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Post-Radical Prostatectomy Inguinal Hernia: A Simple Surgical Intervention can Substantially Reduce the Incidence—Results From a Prospective Randomized Trial
Post-Radical Prostatectomy Inguinal Hernia: A Simple Surgical Intervention can Substantially Reduce the Incidence—Results From a Prospective Randomized Trial Johan Stranne,* Gunnar Aus, Svante Bergdahl, Jan-Erik Damber, Jonas Hugosson, Ali Khatami and Pär Lodding From the Department of Urology, Sahlgrenska University Hospital, Göteborg, Sweden
Abbreviations and Acronyms IH ⫽ inguinal hernia PLND ⫽ pelvic lymph node dissection RRP ⫽ radical retropubic prostatectomy Submitted for publication December 9, 2009. Study received local ethics committee approval. * Correspondence: Department of Urology, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden (telephone: ⫹46-31-3429007; FAX: ⫹46-31821740; e-mail: [email protected]).
Purpose: After radical retropubic prostatectomy a postoperative inguinal hernia develops in 15% to 20% of patients. We investigated whether a simple prophylactic procedure during radical retropubic prostatectomy would reduce this incidence. Materials and Methods: A total of 294 consecutive patients scheduled for radical retropubic prostatectomy at our clinic were prospectively included in the study. Patients with a present inguinal hernia or a previous inguinal hernia surgery were not included in the analysis. The subjects were randomized for side of prophylactic intervention (left or right). At radical retropubic prostatectomy a nonresorbable figure-of-8 suture was placed lateral to the internal ring of the inguinal canal and the spermatic cord on either side according to outcome of the randomization. Patients were followed at regular followup visits at the clinic. At the end of the study all patients were invited for a final interview and examination by an independent examiner who was unaware of the side of intervention. Results: Of the patients 86% (254) showed up for the final examination. The cumulative inguinal hernia incidence was 3.5% on the intervention side and 9.1% on the control side (log rank Mantel-Cox p ⫽ 0.011). There were no serious adverse events, and no increase in postoperative discomfort in the groin and testicular region on the intervention side. The procedure added 5 to 10 minutes to the duration of surgery. Conclusions: The prophylactic procedure was simple and safe to perform, and it decreased the risk of postoperative inguinal hernia formation by 62%. We believe it should be considered for patients undergoing radical retropubic prostatectomy. Key Words: prostatectomy; prostatic neoplasms; hernia, inguinal; prevention and control
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INGUINAL hernia is a clinically important complication of radical retropubic prostatectomy, occurring in 15% to 20% of patients within 3 years.1– 6 A majority of postoperative IHs are lateral or indirect, meaning they protrude through a defect in the region of the internal ring of the inguinal canal lateral to the inferior epigastric vessels.2,4 It is likely that the lower mid-
line incision used during RRP affects the integrity of the internal ring and its shutter mechanism and, thereby, is of causative importance for the development of postoperative IHs.5–9 In this prospectively randomized study we investigated whether a prophylactic surgical narrowing of the internal ring of the inguinal canal during RRP could decrease post-RRP IH forma-
0022-5347/10/1843-0984/0 THE JOURNAL OF UROLOGY® © 2010 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
Vol. 184, 984-989, September 2010 Printed in U.S.A. DOI:10.1016/j.juro.2010.04.067
AND
RESEARCH, INC.
SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
tion in patients without a history of IH surgery or clinically overt IH.
MATERIALS AND METHODS Patients eligible for inclusion in this study were men scheduled to undergo RRP at Sahlgrenska University Hospital. Patients with a history of lower abdominal surgery, excluding appendectomy, and those with previous IH repair or a clinical IH on preoperative clinical examination were not eligible for study. A clinical hernia was defined as an IH detectable on physical groin examination before RRP regardless of patient awareness of the hernia. All RRP procedures were essentially performed using the technique of anatomical RRP described by Walsh.10 All patients underwent simultaneous PLND restricted to the obturator fossa bilaterally. A prophylactic procedure was added on the right or the left groin. The procedure was a simplified version of the method of lateral IH repair during RRP described by Schlegel and Walsh.11 The spermatic cord was mobilized and the area of the internal ring of the inguinal canal was identified. The internal ring was freed of excess fatty tissue. The spermatic cord was retracted medially, and a nonresorbable 2-zero figure-of-8 suture was placed between the transversus arch and the iliopubic tract lateral to the spermatic cord, narrowing the opening of the internal ring (fig. 1). According to the protocol the same standardized procedure was performed re-
985
gardless of the appearance of the internal ring. The patients were randomized for intervention side by the year of birth, ie the left side if the patient was born in an odd numbered year (1943, 1945 etc) and the right side if the patient was born in an even numbered year (1942, 1944 etc). The patients were not informed of the randomization algorithm or of the intervention side. By this study design each patient formed his own control. A pre-study 80% power calculation estimated a need to include 300 patients to detect a decrease in IH incidence of 50% (10% to 5%) between the intervention and control side. During the recruitment period of approximately 2.5 years (August 2003 to March 2006) 432 patients met the inclusion criteria and were offered participation in the study. An informed consent was obtained from 354 patients who constituted the study group. Of these patients 60 did not receive a prophylactic suture due to technical difficulties during RRP in 12 and due to omission by the urologist or unknown reasons in 48. Thus, a prophylactic procedure was performed according to the study protocol in 294 patients (fig. 2). The duration of surgery and the amount of blood loss were recorded. During followup the patients were examined at regular postoperative visits. In May and June 2008 all patients were invited for an end of study interview and physical groin examination by a physician not previously associated with the project, who was unaware of the randomization algorithm and the side of intervention. At this
Figure 1. Illustration of prophylactic procedure. A, left spermatic cord is retracted medially and nonresorbable 2-zero double suture is placed between transversus arch and iliopubic tract lateral to spermatic cord. B, internal ring of inguinal canal is narrowed. C, line of incision. Reprinted with permission.11
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SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
evaluation the patients were physically examined in the groin in a standing position including a Valsalva maneuver and were interviewed about any surgical procedures for IH at any time after the RRP as well as about discomfort in the groin area. The patients described the nature of any discomfort in their own words. A total of 254 patients (86%) attended the final examination, 127 of whom had the prophylactic procedure performed on the right side and 127 on the left. The final results are based on these patients (fig. 2). We assessed the cumulative IH incidence for the intervention side over time compared to the control side using Kaplan-Meier survival analysis and Kaplan-Meier plots. The difference between the sides was analyzed using the log rank (Mantel-Cox) test. The influence of potential risk factors for IH development was assessed using univariate Cox regression. The study was approved by the local ethics committee.
Cumulative risk of post-RRP inguinal hernia development
Log Rank (Mantel Cox) p=0.011
Control side
Intervention side
Time (months) Patients at risk:
254
244
237
210
115
42
Figure 3. Kaplan-Meier estimated cumulative risk of post-RRP inguinal hernia.
RESULTS Inguinal hernia developed in 28 patients during followup. Of these hernias 5 occurred on the intervention side, 19 were on the control side and 4 were bilateral. The total estimated cumulative incidence of IH after 36 months on Kaplan-Meier survival analysis was 12.6%, ie 3.5% on the intervention side and 9.1% on the control side. The postoperative IH reduction on the intervention vs the control side was 62% (log rank Mantel-Cox p ⫽ 0.011) (fig. 3).
Mean followup was 38.4 months (median 37.7, range 27.4 to 56.0). Mean, median and range of age, body mass index, duration of surgery and blood loss are shown in table 1. None of these factors influenced the risk of IH development. Intraoperative complications consisted of 2 cases of external iliac vein puncture by the needle when the suture was placed and 1 case of bleeding from the plexus pampiniformis around the spermatic cord. The first 2 cases were managed with the application of a monofilament 6-zero vascular suture over the puncture in the iliac vessel wall and the third case was managed with ligation of some of the veins in the plexus. Bleeding was minimal and none of these patients presented with any further postoperative complications or discomfort. Discomfort at any time postoperatively, usually of a slight degree, was expressed on direct questioning by 30 patients at the end of study evaluation and/or at regular followup visits. The rate and nature of postoperative discomfort from the groin and testicular region are summarized in table 2. The prophylactic procedure on 1 side added approximately 5 to 10 minutes to the duration of the RRP procedure.
Table 1
Figure 2. Inclusion algorithm of study, and reasons for dropout at RRP and at followup visit. 1, previous inguinal hernia surgery in 105 patients, clinical IH in 43 and complicating comorbidity, eg previous kidney transplantation, urinary diversion or rectal amputation, in 5. 2, technical difficulties during RRP in 12 patients, other reasons in 48. 3, 9 patients deceased, 6 moved and 25 no-show at followup visit.
Age Body mass index (kg/m2) Duration of surgery (mins) Blood loss (ml)
Mean
Median (range)
p Value
95% CI
62.9 26.1
62.8 (43.0–73.4) 25.4 (19.8–40.6)
0.919 0.102
0.933–1.080 0.672–1.037
(68–209)
0.230
0.977–1.006
900 (100–4,500)
0.915
0.999–1.001
130 1,073
130
Statistics refer to IH development according to each investigated factor in a univariate Cox proportional hazards test.
SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
Table 2. Postoperative discomfort
Slight discomfort/prickling Small lump Severe discomfort/pain Infection (epididymitis) Lymphocele Totals
No. Intervention Side
No. Control Side
No. Bilat
7 1 0 1 0
5 2 1 0 1
10 0 2 0 0
9
9
12
DISCUSSION Our results show that a prophylactic narrowing of the internal ring of the inguinal canal decreases the post-RRP IH incidence on the intervention side by 62% (p ⫽ 0.011). Furthermore, the addition of the narrowing suture was feasible and safe. Inguinal hernias develop in approximately 15% to 20% of patients after undergoing RRP.1– 6 When considering the addition of a prophylactic surgical maneuver to prevent this problem it is essential that the method is safe, efficient and easy to perform. Our results show that the prophylactic procedure we describe has few, if any, complications perioperatively and it did not lead to late complications (table 2). The method we used is a simplification of a previously well described method for the repair of lateral IHs during RRP.11 This method of repair leaves only the suture as foreign material in the surgical area. To understand why the simplified version of the method is efficient it is important to consider the likely mechanism of post-RRP IH formation. As mentioned previously a majority of the post-RRP IHs are indirect.2,4 A patent processus vaginalis has historically been considered mandatory for indirect IH formation and has a prevalence of approximately 20%.12,13 However, this notion has been challenged and the cause of indirect herniation is likely multifactorial.14 Defects of the supportive tissues of the shutter mechanism, by incrimination of the action of the lateral abdominal muscles by denervation15 or by defects in the connective tissues of the fasciae layers,16 probably contribute to this type of herniation as well. Koie et al suggest that the length of the incision is of importance for IH development.8 They reported a postoperative IH incidence as high as 38.7% after conventional RRP but only 2.9% in a group of 272 patients in whom the procedure was performed through a so-called mini-laparotomy incision of only 6 cm. Matsubara et al also reported an IH incidence of 1.8% after radical perineal prostatectomy in which the whole procedure was performed through a perineal incision and consequently there was no abdominal incision at all.17 Thus, the incision itself as well as the length of the abdominal incision seem to
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affect the postoperative development of IH. We previously demonstrated that IH development is also a frequent complication after other types of urological surgery in men such as cystectomy, open surgery for benign prostatic enlargement and PLND.6,9 Thus, the common denominator for postoperative IH seems to be the lower midline incision. The incision may cause the IH by a disruption of the anatomical-physiological balance between the different fascia layers of the abdominal wall, thereby impairing the shutter mechanism of the inguinal canal.3 By narrowing the internal ring of the inguinal canal as we have done in this study this balance is not restored. However, we believe that the narrowing suture and the subsequent scar tissue formation in the area prevents the bowel from protruding through the ring in most cases, despite the defective shutter mechanism, thereby preventing indirect IH formation. Fujii et al recently described a significant reduction of post-RRP IH by opening the funicle, and identifying and transecting the processus vaginalis/ peritoneal residue found inside.18 The outcome, when compared to a historical control group, suggests a good prophylactic effect, and scar tissue formation around the internal ring is likely important, especially in cases in which no processus vaginalis was found. Results from a small study by Sakai et al, in which mere blunt dissection and isolation of the spermatic cord during RRP reduced the incidence of IH, further suggest that scar tissue formation is important.19 The preventive effect at the internal ring of our chosen method is not absolute, as demonstrated by the occurrence of a few postoperative IHs on the intervention side in our study, but it is still remarkably efficient. The method of surgery in the present study was standardized and all patients underwent simultaneous PLND. Although PLND has previously been shown not to add to the incidence of post-RRP IH formation when performed during RRP, we considered it important that the various steps of the operation be simple and identical in all patients.20 This included the technique for applying the prophylactic suture. Therefore, no distinction was made in the protocol between patients with a normal internal ring, a patent processus vaginalis or a small subclinical IH at surgery. The prevalence of subclinical lesions, depending on the method of detection,21 is reported to be between 13% and 33%.9,22–24 It is plausible that such lesions will be prone to develop into clinically symptomatic IHs if the negative impact of a lower midline incision, for instance during RRP, is added. In view of our results some patients with subclinical IHs have probably been protected from clinical IH formation in 1 of their groins by performance of the prophylactic procedure. Regret-
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SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
tably the presence of subclinical IHs was not specifically recorded during our study so no firm conclusions can be drawn on the effectiveness of the procedure in the repair of subclinical defects. When studying the effect of prophylactic surgical measures during RRP to reduce post-RRP IH, several issues need to be addressed. It is important to study a group of patients that is as homogenous as possible in terms of relevant preoperative risk factors and the method in which the surgery was performed. This homogeneity ensures that any difference in outcome can actually be attributed to the intervention performed rather than other factors. By randomizing the side of the prophylactic intervention we were able to minimize the influence of unrelated factors and each patient could serve as his own control regarding hernia development in each groin. We also limited our study group to patients who were without past or present IH morbidity. Patients who underwent previous IH surgery or those with a prevalent unilateral IH have a post-RRP IH incidence of 18% to 30%.5,20,22,25 These IHs are predominantly on the contralateral side of the previous lesion.20 Thus, the inclusion of such patients in this study would jeopardize the study interpretation since the groins would be at different risks for hernia and, furthermore, would obviously be unsuitable to act as their own controls. Therefore, it is important to note that the total cumulative incidence of post-RRP IH demonstrated in the present study of selected patients (12.6% at 36 months) should not be compared to that of other studies, which usually report higher incidence figures.1– 6 Due to the study design with patients being their own controls we have no control group for duration of surgery and blood loss.
What effects can be anticipated if this prophylactic procedure were also to be used on patients with IH morbidity in the form of previous surgery or present hernia? In fact, it is likely that such patients would especially benefit from a prophylactic procedure on the previously not operated side because this side has an increased risk of post-RRP IH.2,5,20,22,25 We believe that in patients who present with a hernia that is large enough to be detected at clinical examination, regardless of whether it is symptomatic, a regular hernia repair should be performed. Various methods to perform this repair during RRP have been discussed by several authors.11,26,27 IH causes discomfort for patients, is potentially dangerous, and is costly for the individual and for society. A 62% reduction in post-RRP IH incidence would lead to a reduction within 3 years from approximately 15% to 20%, to 6% to 8%.1– 6 Considering the high number of radical prostatectomies performed the prophylactic method has the potential to be beneficial in a large number of patients. The impact might be even greater if the prophylaxis were to be used on male patients also undergoing other surgical procedures involving the use of a lower midline incision. Preoperative identification and adequate repair of prevalent IH will likely reduce the incidence further.
CONCLUSIONS A prophylactic narrowing of the internal ring of the inguinal canal with a lateral suture reduced the risk of post-RRP IH formation by 62% in the selected group of patients without preoperative IH morbidity. This method is easy and safe, causes few if any complications and, therefore, should be considered for these patients.
REFERENCES 1. Regan TC, Mordkin RM, Constantinople NL et al: Incidence of inguinal hernias following radical retropubic prostatectomy. Urology 1996; 47: 536. 2. Lodding P, Bergdahl C, Nyberg M et al: Inguinal hernia after radical retropubic prostatectomy for prostate cancer: a study of incidence and risk factors in comparison to no operation and lymphadenectomy. J Urol 2001; 166: 964. 3. Stranne J: Inguinal hernia after urologic surgery in males with special reference to radical retropubic prostatectomy. A clinical, epidemiological and methodological study. Department of Urology, Institute of Clinical Sciences, the Sahlgrenska Academy at Göteborg University, Sahlgrenska University Hospital, Göteborg, Sweden 2006.
4. Abe T, Shinohara N, Harabayashi T et al: Postoperative inguinal hernia after radical prostatectomy for prostate cancer. Urology 2007; 69: 326. 5. Ichioka K, Kohei N, Yoshimura K et al: Impact of retraction of vas deferens in postradical prostatectomy inguinal hernia. Urology 2007; 70: 511. 6. Stranne J, Hugosson J and Lodding P: Inguinal hernia is a common complication in lower midline incision surgery. Hernia 2007; 11: 247. 7. Nomura T, Mimata H, Kitamura H et al: Lower incidence of inguinal hernia: minilaparotomy radical retropubic prostatectomy compared with conventional technique. A preliminary report. Urol Int 2005; 74: 32. 8. Koie T, Yoneyama T, Kamimura N et al: Frequency of postoperative inguinal hernia after en-
doscope-assisted mini-laparotomy and conventional retropubic radical prostatectomies. Int J Urol 2008; 15: 226. 9. Sekita N, Suzuki H, Kamijima S et al: Incidence of inguinal hernia after prostate surgery: open radical retropubic prostatectomy versus open simple prostatectomy versus transurethral resection of the prostate. Int J Urol 2009; 16: 110. 10. Walsh P: Anatomic radical retropubic prostatectomy. In: Campbell’s Urology, 8th ed. Edited by PC Walsh, AB Retik, ED Vaughan Jr et al. Philadelphia: W. B. Saunders 2002; vol 4, pp 3107–3129. 11. Schlegel PN and Walsh PC: Simultaneous preperitoneal hernia repair during radical pelvic surgery. J Urol 1987; 137: 1180.
SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
12. Hughson W: The persistent or preformed sac in relation to oblique inguinal hernia. Surg Gynecol Obstet 1925; 41: 610. 13. van Wessem KJ, Simons MP, Plaisier PW et al: The etiology of indirect inguinal hernias: congenital and/or acquired? Hernia 2003; 7: 76. 14. Fitzgibbons RJJ, Filipi CJ and Quinn TH: Inguinal hernias. In: Schwartz’s Principles of Surgery, 8th ed. Edited by FC Brunicardi, DK Andersen, TR Billiar et al. New York: The McGraw-Hill Companies, Inc. 2005; pp 1353–1394. 15. Arnbjörnsson E: A neuromuscular basis for the development of right inguinal hernia after appendectomy. Am J Surg 1982; 143: 367. 16. Sorensen LT, Jorgensen LN and Gottrup F: Biochemical aspects of abdominal wall hernia formation and recurrence. In: Nyhus and Condon’s Hernia, 5th ed. Edited by RJ Fitzgibbons and AG Greenburg. Philadelphia: Lippincott Williams & Wilkins 2002; pp 9 –16. 17. Matsubara A, Yoneda T, Nakamoto T et al: Inguinal hernia after radical perineal prostatec-
tomy: comparison with the retropubic approach. Urology 2007; 70: 1152.
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operative inguinal hernia: new perspective for radical prostatectomy-related inguinal hernia. Urology 2006; 68: 267.
18. Fujii Y, Yamamoto S, Yonese J et al: A novel technique to prevent postradical retropubic prostatectomy inguinal hernia: the processus vaginalis transection method. Urology 2010; 75: 713.
23. Nielsen ME and Walsh PC: Inguinal hernia repair at the time of radical retropubic prostatectomy. J Urol 2005; 173: 278.
19. Sakai Y, Okuno T, Kijima T et al: Simple prophylactic procedure of inguinal hernia after radical retropubic prostatectomy: isolation of the spermatic cord. Int J Urol 2009; 16: 848.
24. Watson DS, Sharp KW, Vasquez JM et al: Incidence of inguinal hernias diagnosed during laparoscopy. South Med J 1994; 87: 23.
20. Stranne J, Hugosson J and Lodding P: Postradical retropubic prostatectomy inguinal hernia: an analysis of risk factors with special reference to preoperative inguinal hernia morbidity and pelvic lymph node dissection. J Urol 2006; 176: 2072. 21. Rutkow IM: Epidemiologic, economic, and sociologic aspects of hernia surgery in the United States in the 1990s. Surg Clin North Am 1998; 78: 941. 22. Fukuta F, Hisasue S, Yanase M et al: Preoperative computed tomography finding predicts for post-
25. Twu CM, Ou YC, Yang CR et al: Predicting risk factors for inguinal hernia after radical retropubic prostatectomy. Urology 2005; 66: 814. 26. Choi BB, Steckel J, Denoto G et al: Preperitoneal prosthetic mesh hernioplasty during radical retropubic prostatectomy. J Urol 1999; 161: 840. 27. Finley DS, Rodriguez E Jr and Ahlering TE: Combined inguinal hernia repair with prosthetic mesh during transperitoneal robot assisted laparoscopic radical prostatectomy: a 4-year experience. J Urol 2007; 178: 1296.
Abbreviations and Acronyms IH ⫽ inguinal hernia PLND ⫽ pelvic lymph node dissection RRP ⫽ radical retropubic prostatectomy Submitted for publication December 9, 2009. Study received local ethics committee approval. * Correspondence: Department of Urology, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden (telephone: ⫹46-31-3429007; FAX: ⫹46-31821740; e-mail: [email protected]).
Purpose: After radical retropubic prostatectomy a postoperative inguinal hernia develops in 15% to 20% of patients. We investigated whether a simple prophylactic procedure during radical retropubic prostatectomy would reduce this incidence. Materials and Methods: A total of 294 consecutive patients scheduled for radical retropubic prostatectomy at our clinic were prospectively included in the study. Patients with a present inguinal hernia or a previous inguinal hernia surgery were not included in the analysis. The subjects were randomized for side of prophylactic intervention (left or right). At radical retropubic prostatectomy a nonresorbable figure-of-8 suture was placed lateral to the internal ring of the inguinal canal and the spermatic cord on either side according to outcome of the randomization. Patients were followed at regular followup visits at the clinic. At the end of the study all patients were invited for a final interview and examination by an independent examiner who was unaware of the side of intervention. Results: Of the patients 86% (254) showed up for the final examination. The cumulative inguinal hernia incidence was 3.5% on the intervention side and 9.1% on the control side (log rank Mantel-Cox p ⫽ 0.011). There were no serious adverse events, and no increase in postoperative discomfort in the groin and testicular region on the intervention side. The procedure added 5 to 10 minutes to the duration of surgery. Conclusions: The prophylactic procedure was simple and safe to perform, and it decreased the risk of postoperative inguinal hernia formation by 62%. We believe it should be considered for patients undergoing radical retropubic prostatectomy. Key Words: prostatectomy; prostatic neoplasms; hernia, inguinal; prevention and control
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INGUINAL hernia is a clinically important complication of radical retropubic prostatectomy, occurring in 15% to 20% of patients within 3 years.1– 6 A majority of postoperative IHs are lateral or indirect, meaning they protrude through a defect in the region of the internal ring of the inguinal canal lateral to the inferior epigastric vessels.2,4 It is likely that the lower mid-
line incision used during RRP affects the integrity of the internal ring and its shutter mechanism and, thereby, is of causative importance for the development of postoperative IHs.5–9 In this prospectively randomized study we investigated whether a prophylactic surgical narrowing of the internal ring of the inguinal canal during RRP could decrease post-RRP IH forma-
0022-5347/10/1843-0984/0 THE JOURNAL OF UROLOGY® © 2010 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
Vol. 184, 984-989, September 2010 Printed in U.S.A. DOI:10.1016/j.juro.2010.04.067
AND
RESEARCH, INC.
SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
tion in patients without a history of IH surgery or clinically overt IH.
MATERIALS AND METHODS Patients eligible for inclusion in this study were men scheduled to undergo RRP at Sahlgrenska University Hospital. Patients with a history of lower abdominal surgery, excluding appendectomy, and those with previous IH repair or a clinical IH on preoperative clinical examination were not eligible for study. A clinical hernia was defined as an IH detectable on physical groin examination before RRP regardless of patient awareness of the hernia. All RRP procedures were essentially performed using the technique of anatomical RRP described by Walsh.10 All patients underwent simultaneous PLND restricted to the obturator fossa bilaterally. A prophylactic procedure was added on the right or the left groin. The procedure was a simplified version of the method of lateral IH repair during RRP described by Schlegel and Walsh.11 The spermatic cord was mobilized and the area of the internal ring of the inguinal canal was identified. The internal ring was freed of excess fatty tissue. The spermatic cord was retracted medially, and a nonresorbable 2-zero figure-of-8 suture was placed between the transversus arch and the iliopubic tract lateral to the spermatic cord, narrowing the opening of the internal ring (fig. 1). According to the protocol the same standardized procedure was performed re-
985
gardless of the appearance of the internal ring. The patients were randomized for intervention side by the year of birth, ie the left side if the patient was born in an odd numbered year (1943, 1945 etc) and the right side if the patient was born in an even numbered year (1942, 1944 etc). The patients were not informed of the randomization algorithm or of the intervention side. By this study design each patient formed his own control. A pre-study 80% power calculation estimated a need to include 300 patients to detect a decrease in IH incidence of 50% (10% to 5%) between the intervention and control side. During the recruitment period of approximately 2.5 years (August 2003 to March 2006) 432 patients met the inclusion criteria and were offered participation in the study. An informed consent was obtained from 354 patients who constituted the study group. Of these patients 60 did not receive a prophylactic suture due to technical difficulties during RRP in 12 and due to omission by the urologist or unknown reasons in 48. Thus, a prophylactic procedure was performed according to the study protocol in 294 patients (fig. 2). The duration of surgery and the amount of blood loss were recorded. During followup the patients were examined at regular postoperative visits. In May and June 2008 all patients were invited for an end of study interview and physical groin examination by a physician not previously associated with the project, who was unaware of the randomization algorithm and the side of intervention. At this
Figure 1. Illustration of prophylactic procedure. A, left spermatic cord is retracted medially and nonresorbable 2-zero double suture is placed between transversus arch and iliopubic tract lateral to spermatic cord. B, internal ring of inguinal canal is narrowed. C, line of incision. Reprinted with permission.11
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SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
evaluation the patients were physically examined in the groin in a standing position including a Valsalva maneuver and were interviewed about any surgical procedures for IH at any time after the RRP as well as about discomfort in the groin area. The patients described the nature of any discomfort in their own words. A total of 254 patients (86%) attended the final examination, 127 of whom had the prophylactic procedure performed on the right side and 127 on the left. The final results are based on these patients (fig. 2). We assessed the cumulative IH incidence for the intervention side over time compared to the control side using Kaplan-Meier survival analysis and Kaplan-Meier plots. The difference between the sides was analyzed using the log rank (Mantel-Cox) test. The influence of potential risk factors for IH development was assessed using univariate Cox regression. The study was approved by the local ethics committee.
Cumulative risk of post-RRP inguinal hernia development
Log Rank (Mantel Cox) p=0.011
Control side
Intervention side
Time (months) Patients at risk:
254
244
237
210
115
42
Figure 3. Kaplan-Meier estimated cumulative risk of post-RRP inguinal hernia.
RESULTS Inguinal hernia developed in 28 patients during followup. Of these hernias 5 occurred on the intervention side, 19 were on the control side and 4 were bilateral. The total estimated cumulative incidence of IH after 36 months on Kaplan-Meier survival analysis was 12.6%, ie 3.5% on the intervention side and 9.1% on the control side. The postoperative IH reduction on the intervention vs the control side was 62% (log rank Mantel-Cox p ⫽ 0.011) (fig. 3).
Mean followup was 38.4 months (median 37.7, range 27.4 to 56.0). Mean, median and range of age, body mass index, duration of surgery and blood loss are shown in table 1. None of these factors influenced the risk of IH development. Intraoperative complications consisted of 2 cases of external iliac vein puncture by the needle when the suture was placed and 1 case of bleeding from the plexus pampiniformis around the spermatic cord. The first 2 cases were managed with the application of a monofilament 6-zero vascular suture over the puncture in the iliac vessel wall and the third case was managed with ligation of some of the veins in the plexus. Bleeding was minimal and none of these patients presented with any further postoperative complications or discomfort. Discomfort at any time postoperatively, usually of a slight degree, was expressed on direct questioning by 30 patients at the end of study evaluation and/or at regular followup visits. The rate and nature of postoperative discomfort from the groin and testicular region are summarized in table 2. The prophylactic procedure on 1 side added approximately 5 to 10 minutes to the duration of the RRP procedure.
Table 1
Figure 2. Inclusion algorithm of study, and reasons for dropout at RRP and at followup visit. 1, previous inguinal hernia surgery in 105 patients, clinical IH in 43 and complicating comorbidity, eg previous kidney transplantation, urinary diversion or rectal amputation, in 5. 2, technical difficulties during RRP in 12 patients, other reasons in 48. 3, 9 patients deceased, 6 moved and 25 no-show at followup visit.
Age Body mass index (kg/m2) Duration of surgery (mins) Blood loss (ml)
Mean
Median (range)
p Value
95% CI
62.9 26.1
62.8 (43.0–73.4) 25.4 (19.8–40.6)
0.919 0.102
0.933–1.080 0.672–1.037
(68–209)
0.230
0.977–1.006
900 (100–4,500)
0.915
0.999–1.001
130 1,073
130
Statistics refer to IH development according to each investigated factor in a univariate Cox proportional hazards test.
SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
Table 2. Postoperative discomfort
Slight discomfort/prickling Small lump Severe discomfort/pain Infection (epididymitis) Lymphocele Totals
No. Intervention Side
No. Control Side
No. Bilat
7 1 0 1 0
5 2 1 0 1
10 0 2 0 0
9
9
12
DISCUSSION Our results show that a prophylactic narrowing of the internal ring of the inguinal canal decreases the post-RRP IH incidence on the intervention side by 62% (p ⫽ 0.011). Furthermore, the addition of the narrowing suture was feasible and safe. Inguinal hernias develop in approximately 15% to 20% of patients after undergoing RRP.1– 6 When considering the addition of a prophylactic surgical maneuver to prevent this problem it is essential that the method is safe, efficient and easy to perform. Our results show that the prophylactic procedure we describe has few, if any, complications perioperatively and it did not lead to late complications (table 2). The method we used is a simplification of a previously well described method for the repair of lateral IHs during RRP.11 This method of repair leaves only the suture as foreign material in the surgical area. To understand why the simplified version of the method is efficient it is important to consider the likely mechanism of post-RRP IH formation. As mentioned previously a majority of the post-RRP IHs are indirect.2,4 A patent processus vaginalis has historically been considered mandatory for indirect IH formation and has a prevalence of approximately 20%.12,13 However, this notion has been challenged and the cause of indirect herniation is likely multifactorial.14 Defects of the supportive tissues of the shutter mechanism, by incrimination of the action of the lateral abdominal muscles by denervation15 or by defects in the connective tissues of the fasciae layers,16 probably contribute to this type of herniation as well. Koie et al suggest that the length of the incision is of importance for IH development.8 They reported a postoperative IH incidence as high as 38.7% after conventional RRP but only 2.9% in a group of 272 patients in whom the procedure was performed through a so-called mini-laparotomy incision of only 6 cm. Matsubara et al also reported an IH incidence of 1.8% after radical perineal prostatectomy in which the whole procedure was performed through a perineal incision and consequently there was no abdominal incision at all.17 Thus, the incision itself as well as the length of the abdominal incision seem to
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affect the postoperative development of IH. We previously demonstrated that IH development is also a frequent complication after other types of urological surgery in men such as cystectomy, open surgery for benign prostatic enlargement and PLND.6,9 Thus, the common denominator for postoperative IH seems to be the lower midline incision. The incision may cause the IH by a disruption of the anatomical-physiological balance between the different fascia layers of the abdominal wall, thereby impairing the shutter mechanism of the inguinal canal.3 By narrowing the internal ring of the inguinal canal as we have done in this study this balance is not restored. However, we believe that the narrowing suture and the subsequent scar tissue formation in the area prevents the bowel from protruding through the ring in most cases, despite the defective shutter mechanism, thereby preventing indirect IH formation. Fujii et al recently described a significant reduction of post-RRP IH by opening the funicle, and identifying and transecting the processus vaginalis/ peritoneal residue found inside.18 The outcome, when compared to a historical control group, suggests a good prophylactic effect, and scar tissue formation around the internal ring is likely important, especially in cases in which no processus vaginalis was found. Results from a small study by Sakai et al, in which mere blunt dissection and isolation of the spermatic cord during RRP reduced the incidence of IH, further suggest that scar tissue formation is important.19 The preventive effect at the internal ring of our chosen method is not absolute, as demonstrated by the occurrence of a few postoperative IHs on the intervention side in our study, but it is still remarkably efficient. The method of surgery in the present study was standardized and all patients underwent simultaneous PLND. Although PLND has previously been shown not to add to the incidence of post-RRP IH formation when performed during RRP, we considered it important that the various steps of the operation be simple and identical in all patients.20 This included the technique for applying the prophylactic suture. Therefore, no distinction was made in the protocol between patients with a normal internal ring, a patent processus vaginalis or a small subclinical IH at surgery. The prevalence of subclinical lesions, depending on the method of detection,21 is reported to be between 13% and 33%.9,22–24 It is plausible that such lesions will be prone to develop into clinically symptomatic IHs if the negative impact of a lower midline incision, for instance during RRP, is added. In view of our results some patients with subclinical IHs have probably been protected from clinical IH formation in 1 of their groins by performance of the prophylactic procedure. Regret-
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SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
tably the presence of subclinical IHs was not specifically recorded during our study so no firm conclusions can be drawn on the effectiveness of the procedure in the repair of subclinical defects. When studying the effect of prophylactic surgical measures during RRP to reduce post-RRP IH, several issues need to be addressed. It is important to study a group of patients that is as homogenous as possible in terms of relevant preoperative risk factors and the method in which the surgery was performed. This homogeneity ensures that any difference in outcome can actually be attributed to the intervention performed rather than other factors. By randomizing the side of the prophylactic intervention we were able to minimize the influence of unrelated factors and each patient could serve as his own control regarding hernia development in each groin. We also limited our study group to patients who were without past or present IH morbidity. Patients who underwent previous IH surgery or those with a prevalent unilateral IH have a post-RRP IH incidence of 18% to 30%.5,20,22,25 These IHs are predominantly on the contralateral side of the previous lesion.20 Thus, the inclusion of such patients in this study would jeopardize the study interpretation since the groins would be at different risks for hernia and, furthermore, would obviously be unsuitable to act as their own controls. Therefore, it is important to note that the total cumulative incidence of post-RRP IH demonstrated in the present study of selected patients (12.6% at 36 months) should not be compared to that of other studies, which usually report higher incidence figures.1– 6 Due to the study design with patients being their own controls we have no control group for duration of surgery and blood loss.
What effects can be anticipated if this prophylactic procedure were also to be used on patients with IH morbidity in the form of previous surgery or present hernia? In fact, it is likely that such patients would especially benefit from a prophylactic procedure on the previously not operated side because this side has an increased risk of post-RRP IH.2,5,20,22,25 We believe that in patients who present with a hernia that is large enough to be detected at clinical examination, regardless of whether it is symptomatic, a regular hernia repair should be performed. Various methods to perform this repair during RRP have been discussed by several authors.11,26,27 IH causes discomfort for patients, is potentially dangerous, and is costly for the individual and for society. A 62% reduction in post-RRP IH incidence would lead to a reduction within 3 years from approximately 15% to 20%, to 6% to 8%.1– 6 Considering the high number of radical prostatectomies performed the prophylactic method has the potential to be beneficial in a large number of patients. The impact might be even greater if the prophylaxis were to be used on male patients also undergoing other surgical procedures involving the use of a lower midline incision. Preoperative identification and adequate repair of prevalent IH will likely reduce the incidence further.
CONCLUSIONS A prophylactic narrowing of the internal ring of the inguinal canal with a lateral suture reduced the risk of post-RRP IH formation by 62% in the selected group of patients without preoperative IH morbidity. This method is easy and safe, causes few if any complications and, therefore, should be considered for these patients.
REFERENCES 1. Regan TC, Mordkin RM, Constantinople NL et al: Incidence of inguinal hernias following radical retropubic prostatectomy. Urology 1996; 47: 536. 2. Lodding P, Bergdahl C, Nyberg M et al: Inguinal hernia after radical retropubic prostatectomy for prostate cancer: a study of incidence and risk factors in comparison to no operation and lymphadenectomy. J Urol 2001; 166: 964. 3. Stranne J: Inguinal hernia after urologic surgery in males with special reference to radical retropubic prostatectomy. A clinical, epidemiological and methodological study. Department of Urology, Institute of Clinical Sciences, the Sahlgrenska Academy at Göteborg University, Sahlgrenska University Hospital, Göteborg, Sweden 2006.
4. Abe T, Shinohara N, Harabayashi T et al: Postoperative inguinal hernia after radical prostatectomy for prostate cancer. Urology 2007; 69: 326. 5. Ichioka K, Kohei N, Yoshimura K et al: Impact of retraction of vas deferens in postradical prostatectomy inguinal hernia. Urology 2007; 70: 511. 6. Stranne J, Hugosson J and Lodding P: Inguinal hernia is a common complication in lower midline incision surgery. Hernia 2007; 11: 247. 7. Nomura T, Mimata H, Kitamura H et al: Lower incidence of inguinal hernia: minilaparotomy radical retropubic prostatectomy compared with conventional technique. A preliminary report. Urol Int 2005; 74: 32. 8. Koie T, Yoneyama T, Kamimura N et al: Frequency of postoperative inguinal hernia after en-
doscope-assisted mini-laparotomy and conventional retropubic radical prostatectomies. Int J Urol 2008; 15: 226. 9. Sekita N, Suzuki H, Kamijima S et al: Incidence of inguinal hernia after prostate surgery: open radical retropubic prostatectomy versus open simple prostatectomy versus transurethral resection of the prostate. Int J Urol 2009; 16: 110. 10. Walsh P: Anatomic radical retropubic prostatectomy. In: Campbell’s Urology, 8th ed. Edited by PC Walsh, AB Retik, ED Vaughan Jr et al. Philadelphia: W. B. Saunders 2002; vol 4, pp 3107–3129. 11. Schlegel PN and Walsh PC: Simultaneous preperitoneal hernia repair during radical pelvic surgery. J Urol 1987; 137: 1180.
SURGERY FOR INGUINAL HERNIA AFTER RADICAL RETROPUBIC PROSTATECTOMY
12. Hughson W: The persistent or preformed sac in relation to oblique inguinal hernia. Surg Gynecol Obstet 1925; 41: 610. 13. van Wessem KJ, Simons MP, Plaisier PW et al: The etiology of indirect inguinal hernias: congenital and/or acquired? Hernia 2003; 7: 76. 14. Fitzgibbons RJJ, Filipi CJ and Quinn TH: Inguinal hernias. In: Schwartz’s Principles of Surgery, 8th ed. Edited by FC Brunicardi, DK Andersen, TR Billiar et al. New York: The McGraw-Hill Companies, Inc. 2005; pp 1353–1394. 15. Arnbjörnsson E: A neuromuscular basis for the development of right inguinal hernia after appendectomy. Am J Surg 1982; 143: 367. 16. Sorensen LT, Jorgensen LN and Gottrup F: Biochemical aspects of abdominal wall hernia formation and recurrence. In: Nyhus and Condon’s Hernia, 5th ed. Edited by RJ Fitzgibbons and AG Greenburg. Philadelphia: Lippincott Williams & Wilkins 2002; pp 9 –16. 17. Matsubara A, Yoneda T, Nakamoto T et al: Inguinal hernia after radical perineal prostatec-
tomy: comparison with the retropubic approach. Urology 2007; 70: 1152.
989
operative inguinal hernia: new perspective for radical prostatectomy-related inguinal hernia. Urology 2006; 68: 267.
18. Fujii Y, Yamamoto S, Yonese J et al: A novel technique to prevent postradical retropubic prostatectomy inguinal hernia: the processus vaginalis transection method. Urology 2010; 75: 713.
23. Nielsen ME and Walsh PC: Inguinal hernia repair at the time of radical retropubic prostatectomy. J Urol 2005; 173: 278.
19. Sakai Y, Okuno T, Kijima T et al: Simple prophylactic procedure of inguinal hernia after radical retropubic prostatectomy: isolation of the spermatic cord. Int J Urol 2009; 16: 848.
24. Watson DS, Sharp KW, Vasquez JM et al: Incidence of inguinal hernias diagnosed during laparoscopy. South Med J 1994; 87: 23.
20. Stranne J, Hugosson J and Lodding P: Postradical retropubic prostatectomy inguinal hernia: an analysis of risk factors with special reference to preoperative inguinal hernia morbidity and pelvic lymph node dissection. J Urol 2006; 176: 2072. 21. Rutkow IM: Epidemiologic, economic, and sociologic aspects of hernia surgery in the United States in the 1990s. Surg Clin North Am 1998; 78: 941. 22. Fukuta F, Hisasue S, Yanase M et al: Preoperative computed tomography finding predicts for post-
25. Twu CM, Ou YC, Yang CR et al: Predicting risk factors for inguinal hernia after radical retropubic prostatectomy. Urology 2005; 66: 814. 26. Choi BB, Steckel J, Denoto G et al: Preperitoneal prosthetic mesh hernioplasty during radical retropubic prostatectomy. J Urol 1999; 161: 840. 27. Finley DS, Rodriguez E Jr and Ahlering TE: Combined inguinal hernia repair with prosthetic mesh during transperitoneal robot assisted laparoscopic radical prostatectomy: a 4-year experience. J Urol 2007; 178: 1296.