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Open Retromuscular Mesh Repair of Complex Incisional Hernia: Predictors of Wound Events and Recurrence
Accepted Manuscript Open Retromuscular Mesh Repair of Complex Incisional Hernia: Predictors of Wound Events and Recurrence William S. Cobb, MD, FACS, Jeremy A. Warren, MD, Joseph A. Ewing, BS, Alex Burnikel, Miller Merchant, Alfredo M. Carbonell, DO, FACS PII:
S1072-7515(15)00058-7
DOI:
10.1016/j.jamcollsurg.2014.12.055
Reference:
ACS 7720
To appear in:
Journal of the American College of Surgeons
Received Date: 17 December 2014 Accepted Date: 22 December 2014
Please cite this article as: Cobb WS, Warren JA, Ewing JA, Burnikel A, Merchant M, Carbonell AM, Open Retromuscular Mesh Repair of Complex Incisional Hernia: Predictors of Wound Events and Recurrence, Journal of the American College of Surgeons (2015), doi: 10.1016/ j.jamcollsurg.2014.12.055. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT 1 Notes to Copyeditor
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Title Page: Burnikel and Merchant have no degrees
ACCEPTED MANUSCRIPT 2 Open Retromuscular Mesh Repair of Complex Incisional Hernia: Predictors of Wound Events and Recurrence
Miller Merchant, Alfredo M Carbonell, DO, FACS
Disclosure Information: Nothing to disclose.
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Greenville Health System, Department of Surgery, Greenville, SC
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William S Cobb, MD, FACS, Jeremy A Warren, MD, Joseph A Ewing, BS, Alex Burnikel,
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Disclosures outside the scope of this work: Dr Cobb is a paid consultant and is paid for lectures for Ethicon and WL Gore & Associates, receives fellowship support from WL Gore & Associates, receives payments for lectures from Atrium Medical, and is paid for developing educational presentations for Ethicon and Covidien. Dr Carbonell is a paid
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consultant for Ethicon, receives grants and payments for lectures from WL Gore & Associates, and is paid for developing educational presentations for Intuitive and Atrium Medical.
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Presented at the Southern Surgical Association 126th Annual Meeting, Palm Beach, FL, November 30–December 3, 2014.
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Correspondence address: William S. Cobb, MD, FACS Greenville Health System Department of Surgery 701 Grove Road Greenville, SC 29605 864-455-6363 (p) 864-455-1320 (f) [email protected]
Running head: Retromuscular Mesh Repair
ACCEPTED MANUSCRIPT 3 ABSTRACT Background: Mesh repair of incisional hernias has been consistently shown to diminish recurrence rates following repair with an increased risk of infectious complications. We present a
determine predictors of wound events and recurrence.
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consecutive series of elective, retro-rectus mesh repairs of the abdominal wall and attempt to
Study Design: A retrospective review was performed to include elective, retro-muscular mesh
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repairs of complex incisional hernias from 8/2006 to 8/2013. Demographics, operative details, and post-operative events including wound events, surgical site infections, and recurrences were
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recorded.
Results: Over the 7-year period, 255 retro-muscular mesh repairs of midline, incisional defects were performed. Median age was 58 years with an average BMI of 32.2. Size of fascial defect was 181.4 cm2 on average with recurrent defects making up 48% of repairs. Wound events
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occurred in 37.7% of cases; surgical site infections occurred in 19.6% of cases. Recurrence rate was 16.9% with mean time to recurrence of 19.2 months. With respect to mesh type, recurrences were 16.2% with synthetic, 17.1% for bioabsorbable, and 25% for biologic mesh. When
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evaluating polypropylene meshes, recurrence was more likely with lightweight mesh (22.9%) versus midweight mesh (10.6%).(p=0.045). Predictors of surgical site infection (SSI) included
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history of mesh infection (OR 4.8, CI 1.9-12.1; p<0.001) and recurrent repairs (OR 2.5, CI 1.15.8; p<0.05). The only predictor of recurrence was the presence of an SSI (OR 3.1, CI 1.5-6.3; p<0.01).
Conclusions: Wound events are common following open mesh repairs of complex incisional hernias. Previous mesh infections and recurrent repairs increase the likelihood of a surgical site
ACCEPTED MANUSCRIPT 4 infection, which significantly increases the risk of recurrence. Recurrences following retro-rectus
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mesh repairs are significantly higher with lightweight compared to mid-weight meshes.
ACCEPTED MANUSCRIPT 5 Introduction As long as surgeons utilize midline fascial incisions to access the abdominal cavity, incisional hernias will remain an unavoidable problem. There is an inherent risk of hernia
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formation that is quoted as high as 20%, and increases with wound infection and patient factors, such as morbid obesity, tobacco abuse, and immunosuppression. [1] The best approach to provide a durable repair of incisional hernias has not been determined. The numerous
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approaches, types of mesh for repair, and possible locations of mesh placement speak to the uncertainty and lack of clear evidence to support any one repair.
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The benefit of mesh reinforcement in incisional hernia repair has been well established in the literature. The best evidence comes from the Dutch prospective trial comparing mesh to suture repair. With ten-year follow-up, Luijendick and colleagues demonstrate a 32% recurrence rate for mesh versus a 63% recurrence rate for suture-based repairs. These defects were less than
today. [2]
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6-cm in diameter which is considered a small defect for most of the incisional hernias repaired
The retromuscular placement of mesh was popularized by Jean Rives and Rene Stoppa in
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the late 1980s. [3] In the United States, this approach was touted by Dr. George Wantz. The repair utilized the potential space posterior to the rectus sheath. The posterior sheath dissection
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provides release of the rectus muscles and provides a well-vascularized pocket for mesh placement, with closure of the midline fascia to recreate native abdominal wall anatomy. We report our outcomes of consecutive, open, retro-rectus mesh repairs of midline,
incisional hernias. The purpose of our study is to determine predictors of wound events, to include any surgical site event or infection, and assess factors that may portend recurrence.
ACCEPTED MANUSCRIPT 6 Materials and Methods An IRB-approved, retrospective review of the hernia database at the Greenville Health System was performed from August 2006 to August 2013. Patients that underwent an elective,
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open repair of midline incisional defects were included for study. Only patients undergoing mesh-based repairs using a retro-rectus approach were considered. All laparoscopic approaches and hernias not involving the midline, such as isolated flank and parastomal defects were
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excluded. Patients’ electronic hospital record and outpatient office notes were reviewed for operative details and follow-up information. Outcome measures focused on surgical site
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occurrences (SSO), surgical site infections (SSI), and recurrent hernia defects. Wound occurrences were considered any event that resulted in delayed healing of the incision. This definition included wound cellulitis, seroma or hematoma formation, skin or fascial dehiscence, and skin necrosis. Surgical site infections were classified based on criteria established by the
Technique
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Centers for Disease Control (CDC), and were divided into superficial, deep, and organ space.
Patients were selected for open repairs based on size of defect, poor quality of overlying
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skin, presence of enterocutanous fistula or mesh infection, concern for loss of abdominal domain, and patient or surgeon desire. All patients received general anesthesia. Epidural pain catheters
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were utilized selectively. Patients were given preoperative antibiotics within one hour of skin incision. Usually, a single dose of cefazolin was given, unless an allergy is reported and gentamicin and clindamycin are used. Patients are prepped and an antimicrobial-impregnated, adhesive drape placed over the skin of the anterior abdominal wall. If an ostomy was present, it was closed with a silk suture in a figure-of-eight fashion and covered with sterile gauze after skin preparation.
ACCEPTED MANUSCRIPT 7 The abdomen is accessed through a midline incision typically through the previous cicatrix. Any attenuated or ulcerated skin in the midline is excised. The midline is entered through the fascia or hernia sac. Intra-abdominal adhesiolysis is performed at least beyond the
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extent of the rectus muscle. Any intra-abdominal mesh encountered is typically removed to
prevent future problems with adhesions or secondary infection. Any fistulas to previous mesh are dealt with by performing the necessary bowel resection. Once adhesiolysis is complete, a moist
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surgical towel is placed over the visceral contents as protection during dissection of the anterior abdominal wall.
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Dissection of the abdominal wall begins with preserving the hernia sac if reasonable. Once the rectus muscle is identified laterally, the posterior rectus sheath is incised just lateral to the linea alba. The dissection plane continues by peeling the posterior fascia off the belly of the rectus abdominis muscle.. This dissection is extended laterally to identify the inferior epigastric
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vessels coursing along the underside of the rectus muscle. Once the segmental perforating vessels are identified just medial to the semilunar line, the dissection is complete. The retrorectus plane is developed for a distance approximately 5 cm superior and inferior to the hernia defect.
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Most defects involve the entire length of the midline, so this dissection extends from pubic symphysis to xiphoid process. Inferiorly, the posterior rectus sheath becomes transversalis fascia
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and peritoneum. The space of Retzius is developed to the level of the symphysis pubis, dropping the bladder flap. Superiorly, the attachments of the posterior sheath to the inferior rib margin are detached, thus entering the retroxiphoid space. At this level, the dissection is pre-peritoneal allowing for mesh to be extended to the level of the xiphoid. The posterior fascia is released as it inserts onto the linea alba to enter the preperitoneal space alone the midline above and below the defect to allow adequate mesh overlap. After the retromuscular space has been developed for
ACCEPTED MANUSCRIPT 8 mesh placement, the ability to close the anterior fascia is assessed. The anterior fascia is brought toward the midline with thyroid tenaculums. If additional mobilization is needed, either a posterior or anterior components separation is performed. [4,5]
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Once the posterior sheath is adequately developed to provide mesh overlap, the posterior fascia is re-approximated with a running 2-0 polydiaxone suture. An appropriate sized piece of mesh is then selected to fill the entire retrorectus space. Mesh choice is surgeon specific and can
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be permanent synthetic, bioabsorbable, or a biologically derived material. Our preference is a large-pore polypropylene permanent mesh, unless extensive contamination is present, then a
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bioasorbable mesh is utilized. Mesh is secured in the midline at both the superior and inferior aspects. Additional sutures can be placed on either side laterally to ensure the flat position of the mesh. One or two drains are then placed ventral to the mesh. The anterior fascia is then reconstructed over the mesh using a 0 polydiaxone suture in a running fashion.
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Statistical Methods
Continuous bivariate analyses were done using Student's t-test. Continuous nonparametric data were compared using Mann-Whitney U test. Discrete variables were compared
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using Chi-squared test or Fishers Exact test for small sample sizes. P-values < 0.05 were considered indicative of statistical significance. Multivariate logistic regression with a forward
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stepwise selection process was used to identify factors contributing to the likelihood of an SSO, SSI, or recurrence of a retromuscular hernia. All data analyses were completed using R statistical software (R Version 3.0.2)
Results
ACCEPTED MANUSCRIPT 9 Over the seven-year study period, 1181 incisional hernias were performed at the Hernia Center at the Greenville Health System in Greenville, South Carolina. Laparoscopic repairs were performed in 721 cases and were excluded. The breakdown of case volume per year and
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comparison of laparoscopic and open approaches is demonstrated in Figure 1. In the first year of analysis, an open approach was utilized 19% of the time, which increased to 52% in year seven of the study. When considering midline defects repaired utilizing a retromuscular approach, there
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were 255 cases that were included for analysis. Eleven of the patients had an associated flank defect and nine had a parastomal hernia in addition to the midline defect.
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The demographic make-up of this population is shown in Table 1. Mean body mass index (BMI) was 32.2 kg/m2, and 83/255 (32.6%) patients had a BMI of or greater than 35 kg/m2 at the time of repair. Current tobacco use was present in 35.2%, and former smokers (those who had quit tobacco greater than one month prior to surgery) made up 14.5%. Approximately 48%
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of the patients in this series had previous failed attempts at repair; 73 patients had one previous repair, 27 had 2 prior repairs, and 20 had 3 or more previous repairs. The types of failed, previous repairs were open, mesh-based (48.7%), laparoscopic (23.8%), and tissue repairs
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(11.9%). One-third of the patients had a previous wound infection complicating their incision, and previous mesh infection was present in 14% of cases.
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The majority of cases were planned open operations; there were 19 patients that were
converted to an open repair from laparoscopy and were included for analysis. Average area of hernia defect was 181.4 cm2 (range 4 -1080 cm2), and the mean width of the defects was 10.3 cm (range 2 – 28 cm). Based on Centers for Disease criteria, 155 cases (60.4%) were clean, 58 cases (22.7%) were clean-contaminated, 14 (5.5%) were contaminated and 29 (11.4%) were dirty. Stoma closure was performed concomitant to the hernia repair in the class III cases. The
ACCEPTED MANUSCRIPT 10 class IV cases were due to active mesh infections in all cases. The choice of mesh differed significantly based on level of contamination. Permanent, synthetic mesh was chosen in the vast majority of clean cases; bioabsorbable and biologic meshes were used more frequently when
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contamination was present. The incidence of surgical site infection was statistically higher in the cases where contamination was present compared to clean cases. [Table 2] Previous mesh was removed in 68 cases; most commonly, this mesh was positioned in the intra-peritoneal location.
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Mean operating times were 230.5 minutes (range; 74 – 561 minutes). Median estimated blood loss was 100 mL (range; 5 - 950 mL).
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Mesh was placed in the retro-muscular position in all cases. Synthetic mesh was utilized in 204 cases and comprised polypropylene (164) and polyester (40). Biologic grafts were employed in 16 cases and bioabsorbable mesh in 35 cases. Average mesh size used in the repairs was 506.1 cm2 (range; 25 – 2072 cm2).
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An adjunctive components separation was utilized in combination with the retromuscular dissection in 150 cases (58.8%). A tranversus abdominis release was performed in 104 repairs, and release of the external oblique aponeurosis was used in 46 instances. Midline closure
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of the anterior fascia was achieved in 91.8% of cases. Drains were placed ventral to the mesh in 195 cases (76.5%). Concomitant panniculectomy was performed in 34 cases.
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A total of 128 wounds events occurred in 96 patients (37.7%). These included seroma
(49), skin dehiscence (39), cellulitis (17), and hematoma (11). Surgical site infection resulted in 50 patients (19.6%). The location of these infections were superficial (30), deep (17), and organ space (6). Mesh explantation was necessitated in only 5 cases (2%). Anterior fascial closure lowered the incidence of wound events (36% vs 57.9%) and surgical site infections (19.1% vs 26.3%) when compared to the repairs where fascial closure was not possible. [Table 3]
ACCEPTED MANUSCRIPT 11 Performing a components separation increased the incidence of both SSO (42.0% vs 31.4%; p=0.086) and SSI (21.3% vs 17.1%; p=0.407) compared to no components separation, but the difference was not significant. In the 34 patients in whom a concomitant panniculectomy was
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performed, the rates of SSO (44.1% vs 36.7%) and SSI (17.7% vs 19.9%) were not significantly increased. The only predictors of surgical site infection (SSI) were history of mesh infection (OR 4.8, CI 1.9-12.1; p<0.001) and recurrent repairs (OR 2.5, CI 1.1-5.8; p<0.05).
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Non-infectious complications occurred in 76 patients (29.8%). The majority of these complications were due to ileus (27) or partial small bowel obstruction (3). There were 4
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anastomotic leaks that occurred postoperatively. Cardiac arrhythmias occurred in 7 patients, and respiratory insufficiency was resulted in 13 patients. Thromboembolic complications occurred in 3 patients, two of which developed a pulmonary embolus. Renal complications included acute tubular necrosis in three and urinary tract infection in six patients. Re-admission rates within 30
failure in each case.
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days of discharge were 8.6%. Rate of mortality was 1.2%. The cause of death was respiratory
With a mean follow-up of 17 months, there were 43 hernia recurrences (16.9%). The
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mean time to recurrence was 19.2 months. The characteristics of the patients who developed recurrences and those who did not are demonstrated in Table 4. The median body mass index
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and presence of chronic obstructive pulmonary disease were significantly higher in the recurrence group. With respect to mesh type, recurrence rates were 16.2% with synthetic mesh, 17.1% for bioabsorbable mesh, and 25% for biologic mesh. Of the recurrences seen in the permanent mesh group, two-thirds occurred in the lightweight mesh patients. When evaluating polypropylene meshes alone, a significant difference in incidence of recurrence was seen when comparing lightweight mesh (22.9%) and midweight mesh (10.6%). (p=0.045) The mechanism
ACCEPTED MANUSCRIPT 12 of recurrence was central mesh fracture or failure in nearly half of the recurrences (46.5%). The incidence of recurrence was higher (31.6%) when fascial closure was not achieved compared to patients who had their anterior fascia closed (16.1%), although there were only 19 patients that
wound infection (odds ratio 3.09; CI 1.50-6.35).
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did not have anterior closure. The only predictor of recurrence was the presence of previous
Following their hernia repair, 57 patients required additional operations. The cause for
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reoperation was for management of infectious complications in 20 patients. Repair of recurrent hernia was the indication for reoperation in 23 cases, and this repair was performed
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laparoscopically with mesh in 18 of these patients. In 10 patients, the indication for additional surgery was unrelated to the index hernia repair, such as sigmoid colectomy for diverticulitis and resection of ovarian mass. Delayed bowel obstructions requiring surgery occurred in 4 patients. The cause of the obstruction in three of these cases was an inter-parietal defect that occurred as a
Discussion
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result of the breakdown of the posterior sheath closure.
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The benefit of the retrorectus space in the repair of abdominal wall defects has been touted over the years. Dr. Usher described dissection of the posterior sheath to create a pocket to house
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the polyethylene mesh that he used for reinforcement of the anterior abdominal wall. [6] Jean Rives and Rene Stoppa were advancing the understanding of the retro-muscular dissection concurrently in the 1980s. Stoppa utilized the space deep to the rectus abdominis below the arcuate line to perform the giant reinforcement of the visceral sac for complex and bilateral inguinal hernias. [3] George Wantz was the biggest advocate of the retro-rectus space in the United States. Once mastering the technique under the tutelage of Rives and Stoppa, he
ACCEPTED MANUSCRIPT 13 beautifully demonstrated the steps in his atlas that many still reference for the approach. In describing his components separation, Oscar Ramirez realized the value of releasing the posterior sheath. While he did not utilize the space to accommodate mesh, he appreciated the
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additional mobilization of the rectus muscles that the release provided. [4]
Utilizing the retro-rectus technique provides two advantages in the reconstruction of complex abdominal wall defects. It does provide a release of the rectus abdominis muscle, which affords
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approximately 2 cm of medialization of the muscle to assist with closure of the anterior fascia. [7] More importantly, the posterior rectus sheath is a potential space that is easily dissected free
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from the overlying muscle, providing a well-vascularized compartment for both synthetic and biologic mesh. This feature distinguishes it from the anterior sheath, which is densely adherent to the tendinous inscriptions of the rectus muscle. Mesh placed in the retro-rectus plane demonstrates more of both type I and type III collagen deposition in a porcine model, when
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compared to the onlay position for mesh. [8] In the only prospective trial utilizing biologic mesh in complex incisional repairs, the recurrence rate was less in the patients where the graft was placed in the retro-rectus position (10%) compared to the intra-peritoneal location (30%). [9] A
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recent meta-analysis evaluating 1,173 sublay repairs compared to 775 onlay repairs demonstrated significantly less recurrences and surgical site infections in the sublay group. [10] In a single
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institution study with one-year follow-up, Venclauskas and colleagues demonstrated wound complications in 49.1% of onlay patients versus 24% of sublay repairs. The incidence of seroma was significantly higher in the onlay repair (45%) compared to the sublay (24%). [11] The retromuscular repair provides two a two-layered closure of the midline. The approach requires adequate mobilization of both the posterior and anterior components in order to achieve this closure. The posterior mobilization may be enhanced by preserving the hernia sac to use for
ACCEPTED MANUSCRIPT 14 re-approximation or by use of the underlying omentum, which is rather healthy is most incisional hernia patients. In extreme cases where there is not enough tissue to close the posterior layer, a bioabsorbable or biologic mesh may be used to recreate the posterior layer. By recreating the
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visceral sac with closure of the posterior layer, the underlying viscera are protected from mesh placed in the retromuscular position. The extra-abdominal location of mesh has a distinct advantage over the intra-peritoneal position. Mesh present in the intra-peritoneal cavity
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significantly complicates additional abdominal surgeries. The chance of subsequent abdominal procedures following hernia repair has been reported at 17%, with recurrent hernia and surgical
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site infection being the most common reason for reoperation. [12] In this series, 57 patients out of 255 (22.4%) required a reoperation. The majority of these procedures were related to recurrence (23) or infectious complications (20). Halm and associates identify the significant risk of subsequent abdominal surgery when intra-peritoneal polypropylene mesh has been placed. In
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their series, the polypropylene mesh was uncoated, and the incidence of small bowel resection was 20% and development of enterocutaneous fistula was 5% compared to none for both events in patients that did not have mesh. [13] In a retrospective review of sixteen Veterans Affairs
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medical centers using the National Surgical Quality Improvement Project, the incidence of enterotomy or unplanned bowel resection during elective incisional hernia repair was more likely
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to occur following prior mesh repairs. This incidence increased to 20.3% with prior mesh repair compared to 5.3% for primary repair and 5.7% following previous suture repair. [14] Closure of the hernia defect by re-approximating the fascia in the midline is one the real advantages of the open repair. By closing the fascia in the midline with mesh dorsal to the defect, the patient is afforded a reinforced repair, which has advantages from a functional standpoint and from a mesh incorporation aspect. [15] After developing the posterior sheath to house the mesh,
ACCEPTED MANUSCRIPT 15 an assessment of the anterior fascial closure must be made. Components separations can be used as adjuncts to the retro-rectus dissection to provide additional mobilization of the anterior fascia and rectus muscle. A posterior component separation can be performed, by releasing the
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tranversus abdominis muscle at the lateral aspect of the posterior sheath. This maneuver provides access to the preperitoneal space lateral to the rectus sheath and provides additional space for mesh placement. [5] If the defect remaining, after the dissection of the posterior rectus space, is
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significant, an anterior components separation can be performed with the retro-rectus dissection to provide maximum medialization of the rectus muscles. The release of the external oblique
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aponeurosis just laterally to its insertion onto the rectus muscles may be divided by raising skin flaps or with perforator preserving techniques. [16] The external oblique release should not be performed in conjunction with the tranversus abdominis release, for fear of weakening the abdominal wall lateral to the rectus muscle at the linea semilunaris.
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The laparoscopic approach to incisional hernia repair has traditionally involved placing a “patch” behind the ventral defect without attempting restore the native anatomy. While wound complications and recurrence rates are favorable, the long-term concern with this bridging
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approach is that the mesh will eventrate through the open defect and create a pseudohernia or bulge that the patient will appreciate. Some authors have advocated closure of the ventral defect
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laparoscopically via the “shoe-lace” technique or by utilizing the robot to assist with suturing the defect closed. [17] Additionally, an endoscopic components separation technique may be combined with a laparoscopic approach to ventral hernia repair to allow for the re-approximation of larger defects. While these techniques achieve temporary closure of the midline, it is not known if this mass closure approach actually remains intact following the repair, and long-term
ACCEPTED MANUSCRIPT 16 recurrence rates are not available. Additionally, the laparoscopic approach leaves mesh in the intraperitoneal position. The concern with the open approach to incisional hernias remains wound and mesh
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infections. The dissection that is required to accommodate mesh and re-approximate the midline can lead to significant wound complications. The difficulty in interpreting the expected rate of wound morbidity following incisional hernia repair from the literature is the heterogeneity of the
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patient comorbidities, mesh selection, and the types of repair. The expected rate of wound
complications in open incisional hernia repairs with the use of components separation and in
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patients with recurrent repairs, significant history of previous wound complications and elevated mean body mass index ranges from 18 – 31%. [9,18] In this series, wound events occurred in 37.7% of patients, but only 19.5% developed a wound infection as based on the CDC criteria. Operative intervention to manage these infections is uncommon, and, more importantly, the need
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for mesh debridement is very rare (2%).
Contamination at the time of incisional hernia repair significantly impacts the success of the operation. In this series, the use of bioabsorbable and biologic grafts was significantly higher
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when contamination was present. These products add significant cost to the direct cost of the case; however, if wound events and infectious complications can be avoided, cost would be
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offset by offering value to the patient. There was a high usage of synthetic mesh in the contaminated cases in this series (53.5%). The concern in this scenario is the risk of mesh infection, which may require removal; however, only one mesh in the 104 contaminated cases required removal. The incidence of wound events were no different between the clean (Class 1) and contaminated (Class II-IV) cases. As would be expected, the likelihood of a wound infection was significantly elevated in the contaminated group (25.7%) versus the clean group (15.6%). In
ACCEPTED MANUSCRIPT 17 the Class II-IV patients, the infections are more likely to be organ space given that these cases typically involve bowel anastomoses which increase the incidence of leaks and intra-abdominal abscesses. Previously, macroporous polypropylene mesh has been used effectively in the retro-
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rectus space in contaminated fields to reinforce terminal ostomies [19] and provide repair of parastomal defects at the time of ostomy reversal. [20] The concern for mesh infection must be weighed against the concern for recurrence. The role of large-pore synthetics, bioabsorbables,
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and biologic grafts in contaminated has yet to be determined, and ongoing prospective, comparative studies will help provide guidance for these difficult patients.
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Even with a retro-rectus repair that avoids development of subcutaneous skin flaps, the incidence of wound complications is not insignificant. Maneuvers to assess the perfusion of the skin flaps may be an option to improve skin healing. [21] Patient factors can more aggressively be altered to improve wound morbidity. Nicotine use negatively impacts wound healing by
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decreasing tissue oxygenation and attenuated the inflammatory healing response. Patients who abuse tobacco should be required to cease the use of nicotine at least 4 weeks prior to surgery to reverse the impact on the healing response [22]. While not a predictor of infection in this study,
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smoking has been demonstrated to increase the incidence of wound infections and 30-day readmissions in patients undergoing open ventral hernia repair. [23] Other patient comorbidities
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such as morbid obesity and diabetes should be maximized preoperatively in an effort to mitigate wound complications.
Improved understanding of the biocompatibility of meshes for hernia repair has provided enhanced mesh constructs. Reduced weight and larger pore meshes have demonstrated improved incorporation of the mesh in the patient. These features have resulted in improved tensile strength of the repair, enhanced compliance of the abdominal wall, and less compression or
ACCEPTED MANUSCRIPT 18 shrinkage of the mesh over time. [24] Lightweight meshes have been defined as having a density of less than 30 g/m2 of polypropylene. The ideal pore size to allow for enhanced collagen deposition has been determined to be greater than 3 mm2. Increasing the porosity or space
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between mesh filaments has been shown to increase the type I and type III collagen deposition in an animal model. [25] While initial burst testing demonstrated adequate strength in reduced weight meshes, there are long-term concerns with providing durability of abdominal wall repair.
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The failure of these meshes is aggravated by bridged repairs and in morbidly obese patients. [26,27] In our experience, 20 of the 43 recurrences were due to central failures of lightweight
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mesh. Our current practice has changed to utilize a macroporous, midweight mesh construct with a density of polypropylene of 45 g/m2. When evaluating the patients that underwent a retromuscular repair with a midweight, macroporous mesh, in this series, the recurrence rate was 10.6%.
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In conclusion, wound events are common following open mesh repairs of complex incisional hernias. Previous mesh infections and recurrent repairs increase the likelihood of a surgical site infection, which significantly increases the risk of recurrence. Central mesh failures leading to
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recurrence are more commonly seen in repairs with lightweight polypropylene mesh. Recurrences following retro-rectus mesh repairs are not insignificant and can occur several
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months after the repair, which stresses the importance of long-term follow-up in reporting recurrence rates after complex incisional hernia repair.
ACCEPTED MANUSCRIPT 19 References 1.
Yahchouchy-Chouillard E, Aura T, Picone O, et al. Incisional hernias. I. Realted risk
factors. Dig Surg 2003; 20:3-9. Burger JW, Luijendijk RW, Hop WC, et al. Long-term follow-up of a randomized
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controlled trial of suture versus mesh repair of incisional hernia Ann Surg 2004; 240(4):578-83. Stoppa RE, Warlaumont CR, Verhaeghe PJ, et al. Prosthetic repair in the treatment of
groin hernias. Int Surg 1986; 71(3):154-8. 4.
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Ramirez OM, Ruas E, Dellon AL. “Components separation” method for closure of
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abdominal-wall defects: an anatomic and clinical study. Plast Reconstr Surg 1990; 86(3):519-26. Novitsky YW, Elliott HL, Orenstein SB, Rosen MJ. Transversus abdominis muscle
release: a novel approach to posterior component separation during complex abdominal wall reconstruction. Am J Surg 2012; 204(5):709-16.
Usher FC, Ochsner J, Tuttle LL. Use of marlex mesh in the repair of incisional hernias.
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6.
Am Surg 1958; 24(12):969-74. 7.
Nguyen V, Shistek KC. Separation of anatomic components method of abdominal wall
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reconstruction – clinical outcome analysis and an update of surgical modifications using the technique. Clin Plastic Surg 2006; 33(2): 247-57. Binnebosel m, Klink CD, Otto J, et al. Impact of mesh positioning on foreign body
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8.
reaction and collagenous ingrowth in a rabbit model of open incisional hernia repair. Hernia 2010; 14(1)71-7. 9.
Rosen MJ, Denoto G, Itani KM, et al. Evaluation of surgical outcomes of retro-rectus
versus intraperitoneal reinforcement with bio-prosthetic mesh in the repair of contaminated ventral hernias. Hernia 2013; 17(1):31-5.
ACCEPTED MANUSCRIPT 20 10.
Timmermans L, de Goede B, van Dijk SM, et al. Meta-analysis of sublay versus onlay
mesh repair in incisional hernia surgery. Am J Surg 2014; 207(6):980-8. 11.
Venclauskas L, Maleckas A, Kiudelis M. One-year follow-up after incisional
12.
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herniatreatment: results of a prospective randomized study. Hernia 2010; 14(6):575-82.
Liang MK, Li LT, Nguyen MT, et al. Abdominal reoperation and mesh explantation
following open ventral hernia repair with mesh. Am J Surg 2014; 208(4):670-6.
Halm JA, deWall LL, Steyerberg EW, et al. Intraperitoneal polypropylene mesh hernia
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13.
repair complicates subsequent abdominal surgery. Word J Surg 2007; 31:423-29. Gray SH, Vick CC, Graham LA, et al. Risk of complications from enterotomy or
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14.
unplanned bowel resection during elective hernia repair. Arch Surg 2008; 143(6):582-6. 15.
Culbertson EJ, Xing L, Wen Y, Franz MG. Reversibility of abdominal wall atrophy and
fibrosis after primary or mesh herniorrhaphy.Ann Surg 2013; 257(1):142-9. Saulis AS, Dumanian GA. Periumbilical rectus abdominis perforator preservation
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16.
significantly reduces superficial wound complications in “separation of parts” hernia repairs. Plast Reconstr Surg 2002; 109(7):2275-80.
Orenstein SB, Dumeer JL, Monteagudo J, et al. Outcomes of laparoscopic ventral hernia
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17.
7. 18.
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repair with routine defect closure using “shoelacing” technique. Surg Endosc 2011; 25(5):1452-
Roth JS, Braithwaite C, Hacker H, et al. Complex ventral hernia repair with a human
acellular dermal matrix. Hernia 2014 Apr 12 [Epub ahead of print] 19.
Janes A, Cengiz Y, Israelsson LA. Preventing parastomal hernia with a prosthetic mesh: a
5-year follow-up of a randomized study. World J Surg 2009; 33(1):118-21.
ACCEPTED MANUSCRIPT 21 20.
Carbonell AM, Criss CN, Cobb WS, et al. Outcomes of synthetic mesh in contaminated
ventral hernia repairs.J Am Coll Surg 2013; 217(6):991-8. 21.
Cho J, May A, Ryan H, Tsuda S. Intraoperative use of fluorescent imaging with
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indocyanine green changes management of abdominal wall flaps during open ventral hernia repair. Surg Endosc 2014 Oct 8 [Epub ahead of print] 22.
Sorensen LT. Wound healing and infection in surgery: the pathophysiological impact of
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smoking, smoking cessation, and nicotine replacement therapy: a systemic review. Ann Surg 2012; 255(6)1069-79.
Lovecchio F, Farmer R, Souza J, et al. Risk factors for 30-day readmission in patients
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23.
undergoing ventral hernia repair. Surgery 2014; 155(4):702-10. 24.
Cobb WS, Kercher KW, Heniford BT. The argument for lightweight polypropylene mesh
in hernia repair. Surg Innov 2005; 12(1)63-9.
Pascual G, Rodriguez M, Gomez-Gil V, et al. Early tissue incorporation and collagen
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25.
deposition in lightweight polypropylene meshes: bioassay in an experimental model of ventral hernia. Surgery 2008;144:427-435.
Petro CC, Nahabet EH, Criss CN, et al. Central failures of lightweight monofilament
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26.
print] 27.
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polyester mesh causing hernia recurrence: a cautionary note. Hernia 2014 Mar 23 [Epub ahead of
Zuvela M, Galun D, Djuric-Stefanovic A, et al. Central rupture of low-weight
polypropylene mesh following recurrent incisional sublay hernioplasty. Hernia 2014; 18(1):13540.
ACCEPTED MANUSCRIPT 22 Table 1. Patient Demographics Patient characteristic 58.6 (21-85)
Body Mass Index, kg/m2, mean (range)
32.2 (15.0-66.6)
Previous failed repair, %
47.9
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Age, y, mean (range)
Previous wound infection, %
33.5
14.0
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Previous mesh infection, % Diabetes, %
27.2 35.0
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Tobacco abuse, %
ACCEPTED MANUSCRIPT 23 Table 2. Characteristics of Repairs based on CDC Wound Classification p Value
150 (97.4) 2 (1.3) 2 (1.3) 55 (35.7) 24 (15.6) 18 (11.7) 7 (4.5) 1 (0.6) 3 (1.9) 23 (14.9)
54 (53.5) 33 (32.7) 14 (13.9) 41 (40.6) 26 (25.7) 12 (11.9) 10 (9.9) 5 (5.0) 1 (1.0) 21 (20.8)
< 0.001* < 0.001* < 0.001* 0.432 0.046* 0.963 0.094 0.037* 1.000 0.298
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Class II-IV 101
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n Mesh Synthetic Bioabsorbable Biologic Surgical site occurrence Surgical site infection Superficial Deep Organ Space Mesh explant Recurrence
Class I 154
ACCEPTED MANUSCRIPT 24 Table 3. Impact of Fascial Closure on Recurrence and Wound Events
p Value 0.086 0.058 0.444
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Fascia not closed 19 6 (31.6) 4 (57.9) 5 (26.3)
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n Recurrence SSO SSI
Fascia closed 236 38 (16.1) 85 (36.0) 45 (19.1)
ACCEPTED MANUSCRIPT 25 Table 4. Analysis of Recurrences
59.0 ± 12.0 59 (52.5, 69.5)
58.5 ± 13.4 58.5 (50, 69)
0.805 0.736
33.7 ± 7.2 33.0 (30.2, 37.1)
32.9 ± 9.3 30.0 (25.5, 36.7)
0.141 0.026*
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0.411 0.003* 0.951
25 (53.5) 9 (20.9) 5 (11.6) 6 (14.0)
131 (61.8) 49 (23.0) 9 (4.2) 23 (10.8)
0.310 0.756 0.066 0.598
22 (51.2) 9 (20.9) 10 (23.3) 4 (9.3) 1 (2.3)
128 (60.4) 38 (17.9) 64 (30.2) 26 (12.3) 1 (0.5)
0.263 0.804 0.361 0.796 0.309
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14 (32.6) 25 (58.1) 15 (34.9)
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p Value
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Comparison group 212
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n Age, y Mean ± SD Median (IQR) BMI, kg/m2 Mean ± SD Median (IQR) Comorbidities, n (%) Diabetes COPD Tobacco use Wound class, n (%) 1 2 3 4 Surgical technique, n (%) CST, y/n B Ramirez B TAR Unilateral TAR Endoscopic *Significant.
Recurrence group 43
ACCEPTED MANUSCRIPT 26 FIGURE LEGENDS Figure 1. Trend of laparoscopic and open incisional hernia repairs. Red bar, open; blue bar,
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laparoscopic.
ACCEPTED MANUSCRIPT 27 Precis Wound events are common after retro-rectus mesh repairs of complex incisional hernias. Previous mesh infections and recurrent repairs increase the likelihood of a surgical site infection,
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commonly seen in repairs with lightweight polypropylene mesh.
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which increases the risk of recurrence. Central mesh failures leading to recurrence are more
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Figure
250
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200
150
Open
Laparoscopic
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100
0 2007
2008
2009
2010
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S1072-7515(15)00058-7
DOI:
10.1016/j.jamcollsurg.2014.12.055
Reference:
ACS 7720
To appear in:
Journal of the American College of Surgeons
Received Date: 17 December 2014 Accepted Date: 22 December 2014
Please cite this article as: Cobb WS, Warren JA, Ewing JA, Burnikel A, Merchant M, Carbonell AM, Open Retromuscular Mesh Repair of Complex Incisional Hernia: Predictors of Wound Events and Recurrence, Journal of the American College of Surgeons (2015), doi: 10.1016/ j.jamcollsurg.2014.12.055. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT 1 Notes to Copyeditor
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Title Page: Burnikel and Merchant have no degrees
ACCEPTED MANUSCRIPT 2 Open Retromuscular Mesh Repair of Complex Incisional Hernia: Predictors of Wound Events and Recurrence
Miller Merchant, Alfredo M Carbonell, DO, FACS
Disclosure Information: Nothing to disclose.
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Greenville Health System, Department of Surgery, Greenville, SC
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William S Cobb, MD, FACS, Jeremy A Warren, MD, Joseph A Ewing, BS, Alex Burnikel,
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Disclosures outside the scope of this work: Dr Cobb is a paid consultant and is paid for lectures for Ethicon and WL Gore & Associates, receives fellowship support from WL Gore & Associates, receives payments for lectures from Atrium Medical, and is paid for developing educational presentations for Ethicon and Covidien. Dr Carbonell is a paid
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consultant for Ethicon, receives grants and payments for lectures from WL Gore & Associates, and is paid for developing educational presentations for Intuitive and Atrium Medical.
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Presented at the Southern Surgical Association 126th Annual Meeting, Palm Beach, FL, November 30–December 3, 2014.
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Correspondence address: William S. Cobb, MD, FACS Greenville Health System Department of Surgery 701 Grove Road Greenville, SC 29605 864-455-6363 (p) 864-455-1320 (f) [email protected]
Running head: Retromuscular Mesh Repair
ACCEPTED MANUSCRIPT 3 ABSTRACT Background: Mesh repair of incisional hernias has been consistently shown to diminish recurrence rates following repair with an increased risk of infectious complications. We present a
determine predictors of wound events and recurrence.
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consecutive series of elective, retro-rectus mesh repairs of the abdominal wall and attempt to
Study Design: A retrospective review was performed to include elective, retro-muscular mesh
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repairs of complex incisional hernias from 8/2006 to 8/2013. Demographics, operative details, and post-operative events including wound events, surgical site infections, and recurrences were
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recorded.
Results: Over the 7-year period, 255 retro-muscular mesh repairs of midline, incisional defects were performed. Median age was 58 years with an average BMI of 32.2. Size of fascial defect was 181.4 cm2 on average with recurrent defects making up 48% of repairs. Wound events
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occurred in 37.7% of cases; surgical site infections occurred in 19.6% of cases. Recurrence rate was 16.9% with mean time to recurrence of 19.2 months. With respect to mesh type, recurrences were 16.2% with synthetic, 17.1% for bioabsorbable, and 25% for biologic mesh. When
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evaluating polypropylene meshes, recurrence was more likely with lightweight mesh (22.9%) versus midweight mesh (10.6%).(p=0.045). Predictors of surgical site infection (SSI) included
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history of mesh infection (OR 4.8, CI 1.9-12.1; p<0.001) and recurrent repairs (OR 2.5, CI 1.15.8; p<0.05). The only predictor of recurrence was the presence of an SSI (OR 3.1, CI 1.5-6.3; p<0.01).
Conclusions: Wound events are common following open mesh repairs of complex incisional hernias. Previous mesh infections and recurrent repairs increase the likelihood of a surgical site
ACCEPTED MANUSCRIPT 4 infection, which significantly increases the risk of recurrence. Recurrences following retro-rectus
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mesh repairs are significantly higher with lightweight compared to mid-weight meshes.
ACCEPTED MANUSCRIPT 5 Introduction As long as surgeons utilize midline fascial incisions to access the abdominal cavity, incisional hernias will remain an unavoidable problem. There is an inherent risk of hernia
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formation that is quoted as high as 20%, and increases with wound infection and patient factors, such as morbid obesity, tobacco abuse, and immunosuppression. [1] The best approach to provide a durable repair of incisional hernias has not been determined. The numerous
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approaches, types of mesh for repair, and possible locations of mesh placement speak to the uncertainty and lack of clear evidence to support any one repair.
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The benefit of mesh reinforcement in incisional hernia repair has been well established in the literature. The best evidence comes from the Dutch prospective trial comparing mesh to suture repair. With ten-year follow-up, Luijendick and colleagues demonstrate a 32% recurrence rate for mesh versus a 63% recurrence rate for suture-based repairs. These defects were less than
today. [2]
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6-cm in diameter which is considered a small defect for most of the incisional hernias repaired
The retromuscular placement of mesh was popularized by Jean Rives and Rene Stoppa in
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the late 1980s. [3] In the United States, this approach was touted by Dr. George Wantz. The repair utilized the potential space posterior to the rectus sheath. The posterior sheath dissection
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provides release of the rectus muscles and provides a well-vascularized pocket for mesh placement, with closure of the midline fascia to recreate native abdominal wall anatomy. We report our outcomes of consecutive, open, retro-rectus mesh repairs of midline,
incisional hernias. The purpose of our study is to determine predictors of wound events, to include any surgical site event or infection, and assess factors that may portend recurrence.
ACCEPTED MANUSCRIPT 6 Materials and Methods An IRB-approved, retrospective review of the hernia database at the Greenville Health System was performed from August 2006 to August 2013. Patients that underwent an elective,
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open repair of midline incisional defects were included for study. Only patients undergoing mesh-based repairs using a retro-rectus approach were considered. All laparoscopic approaches and hernias not involving the midline, such as isolated flank and parastomal defects were
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excluded. Patients’ electronic hospital record and outpatient office notes were reviewed for operative details and follow-up information. Outcome measures focused on surgical site
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occurrences (SSO), surgical site infections (SSI), and recurrent hernia defects. Wound occurrences were considered any event that resulted in delayed healing of the incision. This definition included wound cellulitis, seroma or hematoma formation, skin or fascial dehiscence, and skin necrosis. Surgical site infections were classified based on criteria established by the
Technique
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Centers for Disease Control (CDC), and were divided into superficial, deep, and organ space.
Patients were selected for open repairs based on size of defect, poor quality of overlying
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skin, presence of enterocutanous fistula or mesh infection, concern for loss of abdominal domain, and patient or surgeon desire. All patients received general anesthesia. Epidural pain catheters
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were utilized selectively. Patients were given preoperative antibiotics within one hour of skin incision. Usually, a single dose of cefazolin was given, unless an allergy is reported and gentamicin and clindamycin are used. Patients are prepped and an antimicrobial-impregnated, adhesive drape placed over the skin of the anterior abdominal wall. If an ostomy was present, it was closed with a silk suture in a figure-of-eight fashion and covered with sterile gauze after skin preparation.
ACCEPTED MANUSCRIPT 7 The abdomen is accessed through a midline incision typically through the previous cicatrix. Any attenuated or ulcerated skin in the midline is excised. The midline is entered through the fascia or hernia sac. Intra-abdominal adhesiolysis is performed at least beyond the
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extent of the rectus muscle. Any intra-abdominal mesh encountered is typically removed to
prevent future problems with adhesions or secondary infection. Any fistulas to previous mesh are dealt with by performing the necessary bowel resection. Once adhesiolysis is complete, a moist
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surgical towel is placed over the visceral contents as protection during dissection of the anterior abdominal wall.
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Dissection of the abdominal wall begins with preserving the hernia sac if reasonable. Once the rectus muscle is identified laterally, the posterior rectus sheath is incised just lateral to the linea alba. The dissection plane continues by peeling the posterior fascia off the belly of the rectus abdominis muscle.. This dissection is extended laterally to identify the inferior epigastric
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vessels coursing along the underside of the rectus muscle. Once the segmental perforating vessels are identified just medial to the semilunar line, the dissection is complete. The retrorectus plane is developed for a distance approximately 5 cm superior and inferior to the hernia defect.
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Most defects involve the entire length of the midline, so this dissection extends from pubic symphysis to xiphoid process. Inferiorly, the posterior rectus sheath becomes transversalis fascia
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and peritoneum. The space of Retzius is developed to the level of the symphysis pubis, dropping the bladder flap. Superiorly, the attachments of the posterior sheath to the inferior rib margin are detached, thus entering the retroxiphoid space. At this level, the dissection is pre-peritoneal allowing for mesh to be extended to the level of the xiphoid. The posterior fascia is released as it inserts onto the linea alba to enter the preperitoneal space alone the midline above and below the defect to allow adequate mesh overlap. After the retromuscular space has been developed for
ACCEPTED MANUSCRIPT 8 mesh placement, the ability to close the anterior fascia is assessed. The anterior fascia is brought toward the midline with thyroid tenaculums. If additional mobilization is needed, either a posterior or anterior components separation is performed. [4,5]
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Once the posterior sheath is adequately developed to provide mesh overlap, the posterior fascia is re-approximated with a running 2-0 polydiaxone suture. An appropriate sized piece of mesh is then selected to fill the entire retrorectus space. Mesh choice is surgeon specific and can
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be permanent synthetic, bioabsorbable, or a biologically derived material. Our preference is a large-pore polypropylene permanent mesh, unless extensive contamination is present, then a
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bioasorbable mesh is utilized. Mesh is secured in the midline at both the superior and inferior aspects. Additional sutures can be placed on either side laterally to ensure the flat position of the mesh. One or two drains are then placed ventral to the mesh. The anterior fascia is then reconstructed over the mesh using a 0 polydiaxone suture in a running fashion.
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Statistical Methods
Continuous bivariate analyses were done using Student's t-test. Continuous nonparametric data were compared using Mann-Whitney U test. Discrete variables were compared
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using Chi-squared test or Fishers Exact test for small sample sizes. P-values < 0.05 were considered indicative of statistical significance. Multivariate logistic regression with a forward
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stepwise selection process was used to identify factors contributing to the likelihood of an SSO, SSI, or recurrence of a retromuscular hernia. All data analyses were completed using R statistical software (R Version 3.0.2)
Results
ACCEPTED MANUSCRIPT 9 Over the seven-year study period, 1181 incisional hernias were performed at the Hernia Center at the Greenville Health System in Greenville, South Carolina. Laparoscopic repairs were performed in 721 cases and were excluded. The breakdown of case volume per year and
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comparison of laparoscopic and open approaches is demonstrated in Figure 1. In the first year of analysis, an open approach was utilized 19% of the time, which increased to 52% in year seven of the study. When considering midline defects repaired utilizing a retromuscular approach, there
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were 255 cases that were included for analysis. Eleven of the patients had an associated flank defect and nine had a parastomal hernia in addition to the midline defect.
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The demographic make-up of this population is shown in Table 1. Mean body mass index (BMI) was 32.2 kg/m2, and 83/255 (32.6%) patients had a BMI of or greater than 35 kg/m2 at the time of repair. Current tobacco use was present in 35.2%, and former smokers (those who had quit tobacco greater than one month prior to surgery) made up 14.5%. Approximately 48%
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of the patients in this series had previous failed attempts at repair; 73 patients had one previous repair, 27 had 2 prior repairs, and 20 had 3 or more previous repairs. The types of failed, previous repairs were open, mesh-based (48.7%), laparoscopic (23.8%), and tissue repairs
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(11.9%). One-third of the patients had a previous wound infection complicating their incision, and previous mesh infection was present in 14% of cases.
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The majority of cases were planned open operations; there were 19 patients that were
converted to an open repair from laparoscopy and were included for analysis. Average area of hernia defect was 181.4 cm2 (range 4 -1080 cm2), and the mean width of the defects was 10.3 cm (range 2 – 28 cm). Based on Centers for Disease criteria, 155 cases (60.4%) were clean, 58 cases (22.7%) were clean-contaminated, 14 (5.5%) were contaminated and 29 (11.4%) were dirty. Stoma closure was performed concomitant to the hernia repair in the class III cases. The
ACCEPTED MANUSCRIPT 10 class IV cases were due to active mesh infections in all cases. The choice of mesh differed significantly based on level of contamination. Permanent, synthetic mesh was chosen in the vast majority of clean cases; bioabsorbable and biologic meshes were used more frequently when
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contamination was present. The incidence of surgical site infection was statistically higher in the cases where contamination was present compared to clean cases. [Table 2] Previous mesh was removed in 68 cases; most commonly, this mesh was positioned in the intra-peritoneal location.
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Mean operating times were 230.5 minutes (range; 74 – 561 minutes). Median estimated blood loss was 100 mL (range; 5 - 950 mL).
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Mesh was placed in the retro-muscular position in all cases. Synthetic mesh was utilized in 204 cases and comprised polypropylene (164) and polyester (40). Biologic grafts were employed in 16 cases and bioabsorbable mesh in 35 cases. Average mesh size used in the repairs was 506.1 cm2 (range; 25 – 2072 cm2).
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An adjunctive components separation was utilized in combination with the retromuscular dissection in 150 cases (58.8%). A tranversus abdominis release was performed in 104 repairs, and release of the external oblique aponeurosis was used in 46 instances. Midline closure
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of the anterior fascia was achieved in 91.8% of cases. Drains were placed ventral to the mesh in 195 cases (76.5%). Concomitant panniculectomy was performed in 34 cases.
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A total of 128 wounds events occurred in 96 patients (37.7%). These included seroma
(49), skin dehiscence (39), cellulitis (17), and hematoma (11). Surgical site infection resulted in 50 patients (19.6%). The location of these infections were superficial (30), deep (17), and organ space (6). Mesh explantation was necessitated in only 5 cases (2%). Anterior fascial closure lowered the incidence of wound events (36% vs 57.9%) and surgical site infections (19.1% vs 26.3%) when compared to the repairs where fascial closure was not possible. [Table 3]
ACCEPTED MANUSCRIPT 11 Performing a components separation increased the incidence of both SSO (42.0% vs 31.4%; p=0.086) and SSI (21.3% vs 17.1%; p=0.407) compared to no components separation, but the difference was not significant. In the 34 patients in whom a concomitant panniculectomy was
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performed, the rates of SSO (44.1% vs 36.7%) and SSI (17.7% vs 19.9%) were not significantly increased. The only predictors of surgical site infection (SSI) were history of mesh infection (OR 4.8, CI 1.9-12.1; p<0.001) and recurrent repairs (OR 2.5, CI 1.1-5.8; p<0.05).
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Non-infectious complications occurred in 76 patients (29.8%). The majority of these complications were due to ileus (27) or partial small bowel obstruction (3). There were 4
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anastomotic leaks that occurred postoperatively. Cardiac arrhythmias occurred in 7 patients, and respiratory insufficiency was resulted in 13 patients. Thromboembolic complications occurred in 3 patients, two of which developed a pulmonary embolus. Renal complications included acute tubular necrosis in three and urinary tract infection in six patients. Re-admission rates within 30
failure in each case.
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days of discharge were 8.6%. Rate of mortality was 1.2%. The cause of death was respiratory
With a mean follow-up of 17 months, there were 43 hernia recurrences (16.9%). The
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mean time to recurrence was 19.2 months. The characteristics of the patients who developed recurrences and those who did not are demonstrated in Table 4. The median body mass index
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and presence of chronic obstructive pulmonary disease were significantly higher in the recurrence group. With respect to mesh type, recurrence rates were 16.2% with synthetic mesh, 17.1% for bioabsorbable mesh, and 25% for biologic mesh. Of the recurrences seen in the permanent mesh group, two-thirds occurred in the lightweight mesh patients. When evaluating polypropylene meshes alone, a significant difference in incidence of recurrence was seen when comparing lightweight mesh (22.9%) and midweight mesh (10.6%). (p=0.045) The mechanism
ACCEPTED MANUSCRIPT 12 of recurrence was central mesh fracture or failure in nearly half of the recurrences (46.5%). The incidence of recurrence was higher (31.6%) when fascial closure was not achieved compared to patients who had their anterior fascia closed (16.1%), although there were only 19 patients that
wound infection (odds ratio 3.09; CI 1.50-6.35).
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did not have anterior closure. The only predictor of recurrence was the presence of previous
Following their hernia repair, 57 patients required additional operations. The cause for
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reoperation was for management of infectious complications in 20 patients. Repair of recurrent hernia was the indication for reoperation in 23 cases, and this repair was performed
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laparoscopically with mesh in 18 of these patients. In 10 patients, the indication for additional surgery was unrelated to the index hernia repair, such as sigmoid colectomy for diverticulitis and resection of ovarian mass. Delayed bowel obstructions requiring surgery occurred in 4 patients. The cause of the obstruction in three of these cases was an inter-parietal defect that occurred as a
Discussion
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result of the breakdown of the posterior sheath closure.
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The benefit of the retrorectus space in the repair of abdominal wall defects has been touted over the years. Dr. Usher described dissection of the posterior sheath to create a pocket to house
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the polyethylene mesh that he used for reinforcement of the anterior abdominal wall. [6] Jean Rives and Rene Stoppa were advancing the understanding of the retro-muscular dissection concurrently in the 1980s. Stoppa utilized the space deep to the rectus abdominis below the arcuate line to perform the giant reinforcement of the visceral sac for complex and bilateral inguinal hernias. [3] George Wantz was the biggest advocate of the retro-rectus space in the United States. Once mastering the technique under the tutelage of Rives and Stoppa, he
ACCEPTED MANUSCRIPT 13 beautifully demonstrated the steps in his atlas that many still reference for the approach. In describing his components separation, Oscar Ramirez realized the value of releasing the posterior sheath. While he did not utilize the space to accommodate mesh, he appreciated the
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additional mobilization of the rectus muscles that the release provided. [4]
Utilizing the retro-rectus technique provides two advantages in the reconstruction of complex abdominal wall defects. It does provide a release of the rectus abdominis muscle, which affords
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approximately 2 cm of medialization of the muscle to assist with closure of the anterior fascia. [7] More importantly, the posterior rectus sheath is a potential space that is easily dissected free
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from the overlying muscle, providing a well-vascularized compartment for both synthetic and biologic mesh. This feature distinguishes it from the anterior sheath, which is densely adherent to the tendinous inscriptions of the rectus muscle. Mesh placed in the retro-rectus plane demonstrates more of both type I and type III collagen deposition in a porcine model, when
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compared to the onlay position for mesh. [8] In the only prospective trial utilizing biologic mesh in complex incisional repairs, the recurrence rate was less in the patients where the graft was placed in the retro-rectus position (10%) compared to the intra-peritoneal location (30%). [9] A
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recent meta-analysis evaluating 1,173 sublay repairs compared to 775 onlay repairs demonstrated significantly less recurrences and surgical site infections in the sublay group. [10] In a single
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institution study with one-year follow-up, Venclauskas and colleagues demonstrated wound complications in 49.1% of onlay patients versus 24% of sublay repairs. The incidence of seroma was significantly higher in the onlay repair (45%) compared to the sublay (24%). [11] The retromuscular repair provides two a two-layered closure of the midline. The approach requires adequate mobilization of both the posterior and anterior components in order to achieve this closure. The posterior mobilization may be enhanced by preserving the hernia sac to use for
ACCEPTED MANUSCRIPT 14 re-approximation or by use of the underlying omentum, which is rather healthy is most incisional hernia patients. In extreme cases where there is not enough tissue to close the posterior layer, a bioabsorbable or biologic mesh may be used to recreate the posterior layer. By recreating the
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visceral sac with closure of the posterior layer, the underlying viscera are protected from mesh placed in the retromuscular position. The extra-abdominal location of mesh has a distinct advantage over the intra-peritoneal position. Mesh present in the intra-peritoneal cavity
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significantly complicates additional abdominal surgeries. The chance of subsequent abdominal procedures following hernia repair has been reported at 17%, with recurrent hernia and surgical
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site infection being the most common reason for reoperation. [12] In this series, 57 patients out of 255 (22.4%) required a reoperation. The majority of these procedures were related to recurrence (23) or infectious complications (20). Halm and associates identify the significant risk of subsequent abdominal surgery when intra-peritoneal polypropylene mesh has been placed. In
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their series, the polypropylene mesh was uncoated, and the incidence of small bowel resection was 20% and development of enterocutaneous fistula was 5% compared to none for both events in patients that did not have mesh. [13] In a retrospective review of sixteen Veterans Affairs
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medical centers using the National Surgical Quality Improvement Project, the incidence of enterotomy or unplanned bowel resection during elective incisional hernia repair was more likely
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to occur following prior mesh repairs. This incidence increased to 20.3% with prior mesh repair compared to 5.3% for primary repair and 5.7% following previous suture repair. [14] Closure of the hernia defect by re-approximating the fascia in the midline is one the real advantages of the open repair. By closing the fascia in the midline with mesh dorsal to the defect, the patient is afforded a reinforced repair, which has advantages from a functional standpoint and from a mesh incorporation aspect. [15] After developing the posterior sheath to house the mesh,
ACCEPTED MANUSCRIPT 15 an assessment of the anterior fascial closure must be made. Components separations can be used as adjuncts to the retro-rectus dissection to provide additional mobilization of the anterior fascia and rectus muscle. A posterior component separation can be performed, by releasing the
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tranversus abdominis muscle at the lateral aspect of the posterior sheath. This maneuver provides access to the preperitoneal space lateral to the rectus sheath and provides additional space for mesh placement. [5] If the defect remaining, after the dissection of the posterior rectus space, is
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significant, an anterior components separation can be performed with the retro-rectus dissection to provide maximum medialization of the rectus muscles. The release of the external oblique
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aponeurosis just laterally to its insertion onto the rectus muscles may be divided by raising skin flaps or with perforator preserving techniques. [16] The external oblique release should not be performed in conjunction with the tranversus abdominis release, for fear of weakening the abdominal wall lateral to the rectus muscle at the linea semilunaris.
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The laparoscopic approach to incisional hernia repair has traditionally involved placing a “patch” behind the ventral defect without attempting restore the native anatomy. While wound complications and recurrence rates are favorable, the long-term concern with this bridging
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approach is that the mesh will eventrate through the open defect and create a pseudohernia or bulge that the patient will appreciate. Some authors have advocated closure of the ventral defect
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laparoscopically via the “shoe-lace” technique or by utilizing the robot to assist with suturing the defect closed. [17] Additionally, an endoscopic components separation technique may be combined with a laparoscopic approach to ventral hernia repair to allow for the re-approximation of larger defects. While these techniques achieve temporary closure of the midline, it is not known if this mass closure approach actually remains intact following the repair, and long-term
ACCEPTED MANUSCRIPT 16 recurrence rates are not available. Additionally, the laparoscopic approach leaves mesh in the intraperitoneal position. The concern with the open approach to incisional hernias remains wound and mesh
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infections. The dissection that is required to accommodate mesh and re-approximate the midline can lead to significant wound complications. The difficulty in interpreting the expected rate of wound morbidity following incisional hernia repair from the literature is the heterogeneity of the
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patient comorbidities, mesh selection, and the types of repair. The expected rate of wound
complications in open incisional hernia repairs with the use of components separation and in
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patients with recurrent repairs, significant history of previous wound complications and elevated mean body mass index ranges from 18 – 31%. [9,18] In this series, wound events occurred in 37.7% of patients, but only 19.5% developed a wound infection as based on the CDC criteria. Operative intervention to manage these infections is uncommon, and, more importantly, the need
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for mesh debridement is very rare (2%).
Contamination at the time of incisional hernia repair significantly impacts the success of the operation. In this series, the use of bioabsorbable and biologic grafts was significantly higher
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when contamination was present. These products add significant cost to the direct cost of the case; however, if wound events and infectious complications can be avoided, cost would be
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offset by offering value to the patient. There was a high usage of synthetic mesh in the contaminated cases in this series (53.5%). The concern in this scenario is the risk of mesh infection, which may require removal; however, only one mesh in the 104 contaminated cases required removal. The incidence of wound events were no different between the clean (Class 1) and contaminated (Class II-IV) cases. As would be expected, the likelihood of a wound infection was significantly elevated in the contaminated group (25.7%) versus the clean group (15.6%). In
ACCEPTED MANUSCRIPT 17 the Class II-IV patients, the infections are more likely to be organ space given that these cases typically involve bowel anastomoses which increase the incidence of leaks and intra-abdominal abscesses. Previously, macroporous polypropylene mesh has been used effectively in the retro-
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rectus space in contaminated fields to reinforce terminal ostomies [19] and provide repair of parastomal defects at the time of ostomy reversal. [20] The concern for mesh infection must be weighed against the concern for recurrence. The role of large-pore synthetics, bioabsorbables,
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and biologic grafts in contaminated has yet to be determined, and ongoing prospective, comparative studies will help provide guidance for these difficult patients.
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Even with a retro-rectus repair that avoids development of subcutaneous skin flaps, the incidence of wound complications is not insignificant. Maneuvers to assess the perfusion of the skin flaps may be an option to improve skin healing. [21] Patient factors can more aggressively be altered to improve wound morbidity. Nicotine use negatively impacts wound healing by
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decreasing tissue oxygenation and attenuated the inflammatory healing response. Patients who abuse tobacco should be required to cease the use of nicotine at least 4 weeks prior to surgery to reverse the impact on the healing response [22]. While not a predictor of infection in this study,
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smoking has been demonstrated to increase the incidence of wound infections and 30-day readmissions in patients undergoing open ventral hernia repair. [23] Other patient comorbidities
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such as morbid obesity and diabetes should be maximized preoperatively in an effort to mitigate wound complications.
Improved understanding of the biocompatibility of meshes for hernia repair has provided enhanced mesh constructs. Reduced weight and larger pore meshes have demonstrated improved incorporation of the mesh in the patient. These features have resulted in improved tensile strength of the repair, enhanced compliance of the abdominal wall, and less compression or
ACCEPTED MANUSCRIPT 18 shrinkage of the mesh over time. [24] Lightweight meshes have been defined as having a density of less than 30 g/m2 of polypropylene. The ideal pore size to allow for enhanced collagen deposition has been determined to be greater than 3 mm2. Increasing the porosity or space
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between mesh filaments has been shown to increase the type I and type III collagen deposition in an animal model. [25] While initial burst testing demonstrated adequate strength in reduced weight meshes, there are long-term concerns with providing durability of abdominal wall repair.
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The failure of these meshes is aggravated by bridged repairs and in morbidly obese patients. [26,27] In our experience, 20 of the 43 recurrences were due to central failures of lightweight
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mesh. Our current practice has changed to utilize a macroporous, midweight mesh construct with a density of polypropylene of 45 g/m2. When evaluating the patients that underwent a retromuscular repair with a midweight, macroporous mesh, in this series, the recurrence rate was 10.6%.
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In conclusion, wound events are common following open mesh repairs of complex incisional hernias. Previous mesh infections and recurrent repairs increase the likelihood of a surgical site infection, which significantly increases the risk of recurrence. Central mesh failures leading to
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recurrence are more commonly seen in repairs with lightweight polypropylene mesh. Recurrences following retro-rectus mesh repairs are not insignificant and can occur several
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months after the repair, which stresses the importance of long-term follow-up in reporting recurrence rates after complex incisional hernia repair.
ACCEPTED MANUSCRIPT 19 References 1.
Yahchouchy-Chouillard E, Aura T, Picone O, et al. Incisional hernias. I. Realted risk
factors. Dig Surg 2003; 20:3-9. Burger JW, Luijendijk RW, Hop WC, et al. Long-term follow-up of a randomized
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2.
controlled trial of suture versus mesh repair of incisional hernia Ann Surg 2004; 240(4):578-83. Stoppa RE, Warlaumont CR, Verhaeghe PJ, et al. Prosthetic repair in the treatment of
groin hernias. Int Surg 1986; 71(3):154-8. 4.
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3.
Ramirez OM, Ruas E, Dellon AL. “Components separation” method for closure of
5.
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abdominal-wall defects: an anatomic and clinical study. Plast Reconstr Surg 1990; 86(3):519-26. Novitsky YW, Elliott HL, Orenstein SB, Rosen MJ. Transversus abdominis muscle
release: a novel approach to posterior component separation during complex abdominal wall reconstruction. Am J Surg 2012; 204(5):709-16.
Usher FC, Ochsner J, Tuttle LL. Use of marlex mesh in the repair of incisional hernias.
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6.
Am Surg 1958; 24(12):969-74. 7.
Nguyen V, Shistek KC. Separation of anatomic components method of abdominal wall
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reconstruction – clinical outcome analysis and an update of surgical modifications using the technique. Clin Plastic Surg 2006; 33(2): 247-57. Binnebosel m, Klink CD, Otto J, et al. Impact of mesh positioning on foreign body
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8.
reaction and collagenous ingrowth in a rabbit model of open incisional hernia repair. Hernia 2010; 14(1)71-7. 9.
Rosen MJ, Denoto G, Itani KM, et al. Evaluation of surgical outcomes of retro-rectus
versus intraperitoneal reinforcement with bio-prosthetic mesh in the repair of contaminated ventral hernias. Hernia 2013; 17(1):31-5.
ACCEPTED MANUSCRIPT 20 10.
Timmermans L, de Goede B, van Dijk SM, et al. Meta-analysis of sublay versus onlay
mesh repair in incisional hernia surgery. Am J Surg 2014; 207(6):980-8. 11.
Venclauskas L, Maleckas A, Kiudelis M. One-year follow-up after incisional
12.
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herniatreatment: results of a prospective randomized study. Hernia 2010; 14(6):575-82.
Liang MK, Li LT, Nguyen MT, et al. Abdominal reoperation and mesh explantation
following open ventral hernia repair with mesh. Am J Surg 2014; 208(4):670-6.
Halm JA, deWall LL, Steyerberg EW, et al. Intraperitoneal polypropylene mesh hernia
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13.
repair complicates subsequent abdominal surgery. Word J Surg 2007; 31:423-29. Gray SH, Vick CC, Graham LA, et al. Risk of complications from enterotomy or
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14.
unplanned bowel resection during elective hernia repair. Arch Surg 2008; 143(6):582-6. 15.
Culbertson EJ, Xing L, Wen Y, Franz MG. Reversibility of abdominal wall atrophy and
fibrosis after primary or mesh herniorrhaphy.Ann Surg 2013; 257(1):142-9. Saulis AS, Dumanian GA. Periumbilical rectus abdominis perforator preservation
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16.
significantly reduces superficial wound complications in “separation of parts” hernia repairs. Plast Reconstr Surg 2002; 109(7):2275-80.
Orenstein SB, Dumeer JL, Monteagudo J, et al. Outcomes of laparoscopic ventral hernia
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17.
7. 18.
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repair with routine defect closure using “shoelacing” technique. Surg Endosc 2011; 25(5):1452-
Roth JS, Braithwaite C, Hacker H, et al. Complex ventral hernia repair with a human
acellular dermal matrix. Hernia 2014 Apr 12 [Epub ahead of print] 19.
Janes A, Cengiz Y, Israelsson LA. Preventing parastomal hernia with a prosthetic mesh: a
5-year follow-up of a randomized study. World J Surg 2009; 33(1):118-21.
ACCEPTED MANUSCRIPT 21 20.
Carbonell AM, Criss CN, Cobb WS, et al. Outcomes of synthetic mesh in contaminated
ventral hernia repairs.J Am Coll Surg 2013; 217(6):991-8. 21.
Cho J, May A, Ryan H, Tsuda S. Intraoperative use of fluorescent imaging with
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indocyanine green changes management of abdominal wall flaps during open ventral hernia repair. Surg Endosc 2014 Oct 8 [Epub ahead of print] 22.
Sorensen LT. Wound healing and infection in surgery: the pathophysiological impact of
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smoking, smoking cessation, and nicotine replacement therapy: a systemic review. Ann Surg 2012; 255(6)1069-79.
Lovecchio F, Farmer R, Souza J, et al. Risk factors for 30-day readmission in patients
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23.
undergoing ventral hernia repair. Surgery 2014; 155(4):702-10. 24.
Cobb WS, Kercher KW, Heniford BT. The argument for lightweight polypropylene mesh
in hernia repair. Surg Innov 2005; 12(1)63-9.
Pascual G, Rodriguez M, Gomez-Gil V, et al. Early tissue incorporation and collagen
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25.
deposition in lightweight polypropylene meshes: bioassay in an experimental model of ventral hernia. Surgery 2008;144:427-435.
Petro CC, Nahabet EH, Criss CN, et al. Central failures of lightweight monofilament
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26.
print] 27.
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polyester mesh causing hernia recurrence: a cautionary note. Hernia 2014 Mar 23 [Epub ahead of
Zuvela M, Galun D, Djuric-Stefanovic A, et al. Central rupture of low-weight
polypropylene mesh following recurrent incisional sublay hernioplasty. Hernia 2014; 18(1):13540.
ACCEPTED MANUSCRIPT 22 Table 1. Patient Demographics Patient characteristic 58.6 (21-85)
Body Mass Index, kg/m2, mean (range)
32.2 (15.0-66.6)
Previous failed repair, %
47.9
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Age, y, mean (range)
Previous wound infection, %
33.5
14.0
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Previous mesh infection, % Diabetes, %
27.2 35.0
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Tobacco abuse, %
ACCEPTED MANUSCRIPT 23 Table 2. Characteristics of Repairs based on CDC Wound Classification p Value
150 (97.4) 2 (1.3) 2 (1.3) 55 (35.7) 24 (15.6) 18 (11.7) 7 (4.5) 1 (0.6) 3 (1.9) 23 (14.9)
54 (53.5) 33 (32.7) 14 (13.9) 41 (40.6) 26 (25.7) 12 (11.9) 10 (9.9) 5 (5.0) 1 (1.0) 21 (20.8)
< 0.001* < 0.001* < 0.001* 0.432 0.046* 0.963 0.094 0.037* 1.000 0.298
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Class II-IV 101
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n Mesh Synthetic Bioabsorbable Biologic Surgical site occurrence Surgical site infection Superficial Deep Organ Space Mesh explant Recurrence
Class I 154
ACCEPTED MANUSCRIPT 24 Table 3. Impact of Fascial Closure on Recurrence and Wound Events
p Value 0.086 0.058 0.444
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Fascia not closed 19 6 (31.6) 4 (57.9) 5 (26.3)
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n Recurrence SSO SSI
Fascia closed 236 38 (16.1) 85 (36.0) 45 (19.1)
ACCEPTED MANUSCRIPT 25 Table 4. Analysis of Recurrences
59.0 ± 12.0 59 (52.5, 69.5)
58.5 ± 13.4 58.5 (50, 69)
0.805 0.736
33.7 ± 7.2 33.0 (30.2, 37.1)
32.9 ± 9.3 30.0 (25.5, 36.7)
0.141 0.026*
SC 56 (26.4) 72 (34.0) 75 (35.4)
0.411 0.003* 0.951
25 (53.5) 9 (20.9) 5 (11.6) 6 (14.0)
131 (61.8) 49 (23.0) 9 (4.2) 23 (10.8)
0.310 0.756 0.066 0.598
22 (51.2) 9 (20.9) 10 (23.3) 4 (9.3) 1 (2.3)
128 (60.4) 38 (17.9) 64 (30.2) 26 (12.3) 1 (0.5)
0.263 0.804 0.361 0.796 0.309
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14 (32.6) 25 (58.1) 15 (34.9)
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p Value
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Comparison group 212
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n Age, y Mean ± SD Median (IQR) BMI, kg/m2 Mean ± SD Median (IQR) Comorbidities, n (%) Diabetes COPD Tobacco use Wound class, n (%) 1 2 3 4 Surgical technique, n (%) CST, y/n B Ramirez B TAR Unilateral TAR Endoscopic *Significant.
Recurrence group 43
ACCEPTED MANUSCRIPT 26 FIGURE LEGENDS Figure 1. Trend of laparoscopic and open incisional hernia repairs. Red bar, open; blue bar,
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laparoscopic.
ACCEPTED MANUSCRIPT 27 Precis Wound events are common after retro-rectus mesh repairs of complex incisional hernias. Previous mesh infections and recurrent repairs increase the likelihood of a surgical site infection,
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commonly seen in repairs with lightweight polypropylene mesh.
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which increases the risk of recurrence. Central mesh failures leading to recurrence are more
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Figure
250
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200
150
Open
Laparoscopic
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100
0 2007
2008
2009
2010
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1
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50
2011
2012
2013