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A randomized trial comparing metallic and absorbable staples for closure of a Pfannenstiel incision for cesarean delivery
Research
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OBSTETRICS
A randomized trial comparing metallic and absorbable staples for closure of a Pfannenstiel incision for cesarean delivery Catherine A. Feese, MD; Steven Johnson, MD; Emily Jones, MS; Donna S. Lambers, MD OBJECTIVE: The purpose of the study is to compare postoperative
RESULTS: In all, 100 patients enrolled in the study: 50 in each group.
pain, cost, speed of closure, and patient satisfaction of Pfannenstiel skin incisions closed with traditional metallic staples vs absorbable staples after cesarean delivery. It is hypothesized that incisions closed with absorbable staples will cause less postoperative pain than traditional metallic staples. STUDY DESIGN: A randomized, controlled trial was conducted from July 2010 through May 2011. Patients undergoing a scheduled cesarean delivery via a Pfannenstiel skin incision were recruited. Patients were randomized into the control group (metallic staples) or the experimental group (absorbable staples). The postpartum nurse and patient were blinded to the type of staples. Postoperative pain was assessed using a visual analog scale on both postoperative day 1 and day of discharge, and the total dose of oral narcotics taken during the postoperative period was assessed.
Based on visual analog scale scores, there were no significant differences between the 2 groups on postoperative day 1 or day of discharge. There were no significant differences in the total dose of oral narcotics taken or in wound complication rates. The time for skin closure was significantly different: 3.5 1.7 for absorbable and 1.39 0.7 minutes for metallic staples (P < .0001). The calculated cost of each device, including placement and removal, was $285.60 for the absorbable and $150.79 for the metallic staples. CONCLUSION: Postoperative pain is comparable for both devices. The
absorbable staple skin closure time, and therefore cost, is significantly greater than for metallic staples. Key words: absorbable staples, cesarean delivery, Pfannenstiel, postoperative pain, skin closure
Cite this article as: Feese CA, Johnson S, Jones E, et al. A randomized trial comparing metallic and absorbable staples for closure of a Pfannenstiel incision for cesarean delivery. Am J Obstet Gynecol 2013;209:556.e1-5.
C
esarean delivery continues to be the most common surgical procedure in the world, and it is expected that the rates will continue to rise due to multiple factors including declining vaginal birth after cesarean rates, maternal request for cesarean delivery, and macrosomia. With rapidly rising
From the Department of Obstetrics and Gynecology (Drs Feese, Johnson, and Lambers) and Hatton Institute for Research (Ms Jones), Good Samaritan Hospital, Cincinnati, OH. Received April 19, 2013; revised June 20, 2013; accepted Aug. 1, 2013. Incisive Surgical Inc (Plymouth, MN) donated absorbable staple devices. The authors report no conflict of interest. Presented at the 60th Annual Clinical Meeting of the American Congress of Obstetricians and Gynecologists, San Diego, CA, May 5-9, 2012. Reprints not available from the authors. 0002-9378/$36.00 ª 2013 Mosby, Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog.2013.08.001
rates of cesarean deliveries, a welldesigned study in an obstetrical population that compares different skin closure techniques would provide surgeons with more definitive information when choosing a method of skin closure.1,2 The ideal method of closing the skin following a Pfannenstiel incision has not yet been established. Virtually all the studies in the Cochrane Review in 2012 addressing skin closure compare metallic staples and absorbable subcuticular suture. Similar outcomes have been noted in regards to wound infection, pain, and cosmesis.3 Currently, the method of skin closure is a matter of surgeon preference. There is limited evidence regarding which method is considered superior in terms of postoperative pain, patient satisfaction, and cost. This information would be valuable in helping guide surgeons in their choice of skin closure technique. There are even fewer studies that have examined the outcomes associated with some of the newer products on the
556.e1 American Journal of Obstetrics & Gynecology DECEMBER 2013
market for skin closure. One stapling device, INSORB (Incisive Surgical Inc, Plymouth, MN), is a subcuticular absorbable skin stapler. There has been 1 study evaluating this new absorbable stapling device in the obstetrical population, which was retrospective, and revealed less nonsteroidal antiinflammatory drug use, but not postoperative narcotic use.4 Although the manufacturer of the INSORB skin closure device claims that it yields better patient satisfaction compared with traditional staples, there are no clinical outcome data to support these claims. Closure times with the subcuticular staples are estimated to be comparable to traditional metallic staples. Documentation of clinical experience with the absorbable stapling device comments on high levels of patient satisfaction, particularly with respect to reduced anxiety and discomfort associated with removal of traditional metallic staples; but again, there are limited data to support this.5-7
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Obstetrics
FIGURE
Flowchart of patients from enrollment to analysis Assessed for eligibility n = 142
E n r o l l m e n t
Excluded n = 42 Not meeting inclusion criteria n = 32 Declined = 10
Randomized n = 100
A l l o c a t i o n
Metallic staples
F o l l o w u p
Absorbable staples
Allocated to intervention n = 50
Allocated to intervention n = 50
Received allocation n = 50
Received allocation n = 50
No discontinued intervention
No discontinued intervention
Survey not completed n = 32
Survey not completed
6-week postpartum n = 29
At discharge n = 33
VAS not available POD #1 n = 4
6-week postpartum n = 24
VAS not available D/C day n = 6
VAS not available POD #1 n = 3 VAS not available D/C day n = 5
A n a l y s i s
VAS POD #1 n = 47
VAS POD #1 n = 46
VAS D/C day n = 45
VAS D/C day n = 44
Pain pills n = 47
Pain pills n = 48
VAS, visual analog scale. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
The purpose of the study is to compare postoperative pain, cost, speed of closure, and patient satisfaction of Pfannenstiel skin incisions closed with traditional metallic staples vs absorbable staples after cesarean delivery. Our hypothesis is that absorbable staples will result in less pain as compared with metallic staple wound closure.
Good Samaritan Hospital in Cincinnati, OH, who were undergoing a scheduled delivery via cesarean delivery. Approval to conduct this study was obtained from the TriHealth Institutional Review Board. The study was also registered with National Institutes of Health registry of both federally and privately funded clinical trials (identifier no. NCT01198691).
M ATERIALS
Participants The cohort for this study comprised women presenting to Good Samaritan
AND
M ETHODS
A randomized, controlled trial was performed using patients recruited from
Research
Hospital for a scheduled cesarean delivery via Pfannenstiel skin incision, and who met all of the following inclusion criteria: (1) singleton gestation; (2) 18 years of age; and (3) obtained prenatal care through the Good Samaritan Hospital Obstetrics/Gynecology Resident Clinic or the maternal-fetal medicine attending private practice. Excluded from the study were those patients with a history of drug or alcohol abuse, contraindications to postoperative nonsteroidal antiinflammatory drugs or narcotics, and undergoing emergent cesarean delivery. Patients were recruited from July 2010 through May 2011. The Figure reveals the patient flowchart from enrollment to analysis.
Interventions All patients provided informed consent, and were randomized, via sealed envelopes, using a random number generator. The control group received metallic staples using a Proximate PXW35 Skin Stapler (Ethicon Endo-Surgery Inc, Cincinnati, OH) and the experimental group received subcuticular absorbable polylactic/polyglycolic acid staples using a Food and Drug Administratione approved sterile, single-patient-use stapling device. All patients received antibiotics preoperatively within 60 minutes of skin incision. The nursing staff and the patient were blinded to the type of skin closure throughout the postoperative period, and both groups of patients received identical dressings that remained in place until the day of discharge. Prior to using the device, the resident physicians and faculty received an in-service from the company representative on how to place the absorbable sutures. All data were extracted by the primary investigator from the patients’ electronic medical records in OB Trace View (Phillips, Andover, MA). Prenatal records and surveys were obtained either from the Good Samaritan Hospital Obstetrics/Gynecology Resident Clinic or the maternal-fetal medicine attending private practice. Objectives The primary outcome was pain on postoperative day 1, and on the day of
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Research
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Obstetrics
discharge. This was determined by the use of a visual analog scale (VAS) score and the total number and dose of narcotic pills taken by the patient during hospitalization. The VAS score was recorded in the medical record by the postpartum nurse during routine assessments of the patient’s incisional pain on postoperative day 1, and on the day of discharge.8 The total number and type of oral narcotics taken during the postoperative period was determined from the patients’ medical records. Ibuprofen is a self-medication available at the bedside, and therefore, was not counted. All patients were instructed to take 800 mg every 6 hours. The charts were reviewed for any evidence of wound complications, defined as a seroma, cellulitis, hematoma, dehiscence, and wound disruptions. In addition, patients were asked if they were treated for a wound complication on the 6-week postpartum patient survey. Secondary outcomes included time of skin closure, patient satisfaction, and cost. Time of skin closure was recorded by the circulating nurse, using the clock in the operating room in total seconds, and entered into the patient’s medical record. Patient satisfaction was evaluated by a survey that was administered on the day of discharge after the patient’s dressing was removed, but before staple removal, if needed, as well as at the 6-week postpartum visit. Cost was calculated by assessing the cost of the 2 stapling devices used per surgery, operating room costs of $70.00 per 1-minute increments applied to the differences in the times of skin closure between the 2 methods, and the additional costs of staple removal device and registered nurse time for the metallic staples removal (Current Procedural Terminology code 99211). After conducting a power calculation for a 2-group t test with a .050 2-sided significance level, 50 patients were included in each group to have a 90% power to detect the difference of 2.68 in the VAS score.9 For independent samples, t test was used for analyses involving continuous variables, including difference in postoperative pain between the 2 groups. The c2 (or Fisher exact test where
TABLE 1
Maternal demographics Demographic
Absorbable n [ 50
Metallic n [ 50
Maternal age, y
27.38 6.15
28.32 5.63
Race/ethnicity African American Asian Caucasian Pacific Islander
P value .427 .487
23 (46%)
22 (44%)
0 (0%)
2 (4%)
26 (52)
24 (48%)
1 (2%)
2 (4%)
Gestational age, wk
38.86 0.81
38.57 1.60
.251
BMI
36.66 8.05
34.44 7.43
.163
3 (6%)
4 (8%)
> .999
Prior abdominal surgery
44 (88%)
43 (86%)
> .999
Prior CD
41 (82%)
41 (82%)
1.000
Smoker
No. of prior CD
1.51 0.63
1.40 0.54
.406
Anesthesia type Regional
49
49
General
1
1
Intrathecal narcotic
44 (93.6%) (n ¼ 47)
48 (98.0%) (n ¼ 49)
History of Pfannenstiel incision
42 (84%)
42 (84%)
Days from CD to discharge
2.86 0.645 (n ¼ 49)
3.06 0.818 (n ¼ 50)
1.000
.357 1.000 .175
Categorical variables presented as n (%) and continuous variables presented as mean SD. Independent samples t test, 2-tailed, for continuous variables, and c2 or Fisher exact test for categorical variables. BMI, body mass index; CD, cesarean delivery. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
appropriate) was used for analyses involving categorical variables. Software (SPSS, version 19; IBM Corp, Armonk, NY) was used for all analyses.
R ESULTS Of the 100 patients enrolled in the study, 50 received the absorbable staples and 50 received the metallic staples. All patients consented and randomly assigned completed the study protocol, and there were no deviations. There were no significant differences in maternal demographic characteristics between the 2 groups (Table 1). Based on the VAS scores, there was no significant difference between the 2 groups for pain scores on postoperative day 1 or on the day of discharge. Also, there was no significant difference
556.e3 American Journal of Obstetrics & Gynecology DECEMBER 2013
between the 2 groups in the total amount and dose of oral narcotics required during the postoperative period (Table 2). Because there may be differences in efficacy between narcotic medications, only the 95 patients who were prescribed oxycodone (5 mg)/acetaminophen (325 mg) were analyzed. The time for skin closure was significantly different: 3.51 1.7 minutes for absorbable and 1.39 0.69 minutes for metallic staples, P < .001 (Table 3). The rates of wound complications between the 2 groups were comparable, with a total of 4 wound complications in the absorbable staple group, and none in the metallic staple group. These complications included: 1 hematoma, 2 cases of cellulitis, and 1 event of excessive bleeding from the subcuticular layer.
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Obstetrics
TABLE 2
Primary outcome: pain Variable
Absorbable
Metallic
P value
VAS postoperative day 1
2.90 1.54 n ¼ 46
2.56 1.47 n ¼ 47
.279
VAS day of discharge
3.52 5.80 n ¼ 44
2.66 1.47 n ¼ 45
.338
Total no. of narcotic pills (oxycodone [5 mg]/acetaminophen [325 mg])
14 10.18 n ¼ 48
14.4 10.81 n ¼ 47
.851
Continuous variables presented as mean SD. Independent samples t test, 2-tailed, P < .05, 2-tailed test. VAS, visual analog scale score. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
Table 4 shows that the calculated cost of each device, including operating room time, device cost, and cost of removal, was $285.60 for the absorbable and $150.79 for the metallic staples. Surveys at the time of discharge and at the 6-week postpartum visit were assessed for patient satisfaction. A total of 38 initial surveys and 47 of the 6-week postpartum visit surveys were completed. When patients were asked, on their initial and 6week postpartum visit surveys, if they were satisfied with the overall appearance of their incisions, 14 of 17 of those in the absorbable staple group agreed, and 16 of 18 of those in the metallic group agreed. Again, similar results were obtained when patients were asked the same question at their 6-week postpartum visit. A total of 21 of 26 in the absorbable group and 20 of 21 in the metallic group were satisfied with the appearance of their incision. Of
the patients with metallic staples, 48% indicated that they were worried about having their staples removed.
C OMMENT Overall, our results indicate that there is no significant difference between the 2 groups in the amount of postoperative pain, both objectively and subjectively, as assessed by the VAS score, and the total dose of narcotics taken postoperatively. This differs from what has been published for cesarean deliveries4 and in the orthopedic literature.6 In the Nitsche et al4 retrospective cohort study of cesarean deliveries, the investigators found a 1.5-fold decrease in ketorolac use, but not a decrease in ibuprofen and oral narcotics. Our patients routinely have ibuprofen available as a self-medication so the number of pills that the patient took was not assessed.
TABLE 3
Secondary outcomes: wound closure Variable
Absorbable
Metallic
P value
Skin closure time (min), mean
3.51 (1.74) n ¼ 43
1.39 (0.69) n ¼ 37
< .001
Total operative time, min
50.9 (20.59) n ¼ 50
46.4 (9.7) n ¼ 48
.178
EBL (mL), mean
1038.4 (423) n ¼ 49
962.5 (119) n ¼ 46
.234
Wound complication
4 (8.1%) n ¼ 49
0 (0%) n ¼ 46
.118
Categorical variables presented n (%) and continuous variables presented as mean (SD). Independent samples t test, P < .05 Fisher exact test for categorical variables. EBL, estimated blood loss. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
Research
Overall satisfaction rates with respect to cosmesis between the 2 devices appear to be comparable based on survey results. Although this study was not designed to specifically study cosmesis, a simple question on the patient surveys indicated that patients were satisfied with the appearance of the incisions, both at the time of discharge and again at 6 weeks postoperatively. Future studies to examine this relationship are needed to effectively compare cosmesis between these devices. When cost was compared between groups, the average cost of each device, including placement and removal, was $285.60 for the absorbable and $150.79 for the metallic staples, primarily due to the longer skin closure times for the absorbable stapler. An important point to note is that the majority of the surgeons were using the product for the first time, which undoubtedly prolonged closure times. There is a significant learning curve associated with the absorbable device that most likely played a role in the longer skin closure times required for the device. As operators become more experienced with the absorbable device, a significant narrowing of the discrepancy between closure times would be expected. It is important to recognize that although the absorbable stapler is a more expensive option in our study, this is due to longer skin closure times from an unfamiliar stapling device. If with practice, surgeons were able to close the skin with either device in approximately the same time, the cost of absorbable staples would become approximately equal to that of metallic staples. The absorbable staples do eliminate the need for staple removal and eliminates patient anxiety that is associated with the removal process that almost half of the patients indicated on their surveys. Safety is also another concern when using any new skin closure technique. All 4 wound complications occurred in the absorbable group vs none in the metallic group. This discrepancy in complications could be explained by surgeon inexperience with the absorbable staple device. Although these results were not significant, future studies with greater sample size are needed to specifically look at wound complication rates between the
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Research TABLE 4
Calculated costs based on staple device Variable Device
Absorbable Metallic $40.00
$9.00
OR time for skin closure
$245.60
$97.30
Removal device
0
$3.24
RN removal
0
$41.25
Total
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Obstetrics
$285.60
$150.79
OR, operating room; RN, registered nurse. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
devices. Also, the overall cost of a stapling device will increase if the cost of caring for a wound complication is included. Strengths of the study included that it was a randomized controlled trial, and that both the patient and postpartum nurse were blinded. Also, a power calculation was performed and our recruitment goal was met to achieve a 90% power. Objectively and subjectively, we determined that the amount of postoperative pain was equal between the stapling devices.
A limitation of the study was that a nonvalidated patient satisfaction survey was used and that a relatively low response rate was achieved. Our return surveys had only a 38% response rate for the initial patient survey, and a 47% response rate for the 6-week postpartum patient survey. A meaningful conclusion of patient satisfaction cannot be drawn from this low response rate. A post hoc power analysis was conducted because the observed SD varied from the predicted SD used in the a priori calculation, and showed that power was nearly 100% to show a difference of 2.68 in the VAS score on postoperative day 1, but was only 20% to detect the small difference of 0.34 that was actually observed. Although cost remains a considerable barrier to using the absorbable skin closure technique, perhaps it could be offset by the fact that it can eliminate patient worries regarding staple removal, and skin closure times may decrease as surgeons gain more experience with the device. Despite these limitations, this study shows that postoperative pain, patient satisfaction, and wound complication rates are comparable between devices.
556.e5 American Journal of Obstetrics & Gynecology DECEMBER 2013
REFERENCES 1. Altman AD, Allen VM, McNeil SA, Dempster J. Pfannenstiel incision closure: a review of current skin closure techniques. J Obstet Gynaecol Can 2009;31:514-20. 2. Clay FSH, Walsh CA, Walsh SR. Staples vs subcuticular sutures for skin closure at cesarean section delivery: a metaanalysis of randomized, controlled trials. Am J Obstet Gynecol 2011;204:378-83. 3. Mackeen AD, Berghella V, Larsen ML. Techniques and materials for skin closure in caesarean section. Cochrane Database Syst Rev 2012;11:CD003577. 4. Nitsche J, Howell C, Howell T. Skin closure with subcuticular absorbable staples after cesarean section is associated with decreased analgesic use. Arch Gynecol Obstet 2011;284:979-83. 5. Tellis VA. Renal transplant incision closure using new absorbable subcuticular staple device. Clin Transplant 2007;21:410-2. 6. Fisher DA, Bengero LL, Clapp BC, Burgess. A randomized, prospective study of total hip wound closure with resorbable subcuticular staples. Orthopedics 2010;33:665. 7. Cross KJ, Teo EH, Wong SL, et al. The absorbable dermal staple device: a faster, more cost-effective method for incisional closure. Plast Reconstr Surg 2009;124:156-62. 8. Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs 1988;14:9-17. 9. Cepeda MS, Africano JM, Polo R, Alcala R, Carr DB. What decline in pain intensity is meaningful to patients with acute pain? Pain 2003;105:151-7.
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OBSTETRICS
A randomized trial comparing metallic and absorbable staples for closure of a Pfannenstiel incision for cesarean delivery Catherine A. Feese, MD; Steven Johnson, MD; Emily Jones, MS; Donna S. Lambers, MD OBJECTIVE: The purpose of the study is to compare postoperative
RESULTS: In all, 100 patients enrolled in the study: 50 in each group.
pain, cost, speed of closure, and patient satisfaction of Pfannenstiel skin incisions closed with traditional metallic staples vs absorbable staples after cesarean delivery. It is hypothesized that incisions closed with absorbable staples will cause less postoperative pain than traditional metallic staples. STUDY DESIGN: A randomized, controlled trial was conducted from July 2010 through May 2011. Patients undergoing a scheduled cesarean delivery via a Pfannenstiel skin incision were recruited. Patients were randomized into the control group (metallic staples) or the experimental group (absorbable staples). The postpartum nurse and patient were blinded to the type of staples. Postoperative pain was assessed using a visual analog scale on both postoperative day 1 and day of discharge, and the total dose of oral narcotics taken during the postoperative period was assessed.
Based on visual analog scale scores, there were no significant differences between the 2 groups on postoperative day 1 or day of discharge. There were no significant differences in the total dose of oral narcotics taken or in wound complication rates. The time for skin closure was significantly different: 3.5 1.7 for absorbable and 1.39 0.7 minutes for metallic staples (P < .0001). The calculated cost of each device, including placement and removal, was $285.60 for the absorbable and $150.79 for the metallic staples. CONCLUSION: Postoperative pain is comparable for both devices. The
absorbable staple skin closure time, and therefore cost, is significantly greater than for metallic staples. Key words: absorbable staples, cesarean delivery, Pfannenstiel, postoperative pain, skin closure
Cite this article as: Feese CA, Johnson S, Jones E, et al. A randomized trial comparing metallic and absorbable staples for closure of a Pfannenstiel incision for cesarean delivery. Am J Obstet Gynecol 2013;209:556.e1-5.
C
esarean delivery continues to be the most common surgical procedure in the world, and it is expected that the rates will continue to rise due to multiple factors including declining vaginal birth after cesarean rates, maternal request for cesarean delivery, and macrosomia. With rapidly rising
From the Department of Obstetrics and Gynecology (Drs Feese, Johnson, and Lambers) and Hatton Institute for Research (Ms Jones), Good Samaritan Hospital, Cincinnati, OH. Received April 19, 2013; revised June 20, 2013; accepted Aug. 1, 2013. Incisive Surgical Inc (Plymouth, MN) donated absorbable staple devices. The authors report no conflict of interest. Presented at the 60th Annual Clinical Meeting of the American Congress of Obstetricians and Gynecologists, San Diego, CA, May 5-9, 2012. Reprints not available from the authors. 0002-9378/$36.00 ª 2013 Mosby, Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog.2013.08.001
rates of cesarean deliveries, a welldesigned study in an obstetrical population that compares different skin closure techniques would provide surgeons with more definitive information when choosing a method of skin closure.1,2 The ideal method of closing the skin following a Pfannenstiel incision has not yet been established. Virtually all the studies in the Cochrane Review in 2012 addressing skin closure compare metallic staples and absorbable subcuticular suture. Similar outcomes have been noted in regards to wound infection, pain, and cosmesis.3 Currently, the method of skin closure is a matter of surgeon preference. There is limited evidence regarding which method is considered superior in terms of postoperative pain, patient satisfaction, and cost. This information would be valuable in helping guide surgeons in their choice of skin closure technique. There are even fewer studies that have examined the outcomes associated with some of the newer products on the
556.e1 American Journal of Obstetrics & Gynecology DECEMBER 2013
market for skin closure. One stapling device, INSORB (Incisive Surgical Inc, Plymouth, MN), is a subcuticular absorbable skin stapler. There has been 1 study evaluating this new absorbable stapling device in the obstetrical population, which was retrospective, and revealed less nonsteroidal antiinflammatory drug use, but not postoperative narcotic use.4 Although the manufacturer of the INSORB skin closure device claims that it yields better patient satisfaction compared with traditional staples, there are no clinical outcome data to support these claims. Closure times with the subcuticular staples are estimated to be comparable to traditional metallic staples. Documentation of clinical experience with the absorbable stapling device comments on high levels of patient satisfaction, particularly with respect to reduced anxiety and discomfort associated with removal of traditional metallic staples; but again, there are limited data to support this.5-7
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Obstetrics
FIGURE
Flowchart of patients from enrollment to analysis Assessed for eligibility n = 142
E n r o l l m e n t
Excluded n = 42 Not meeting inclusion criteria n = 32 Declined = 10
Randomized n = 100
A l l o c a t i o n
Metallic staples
F o l l o w u p
Absorbable staples
Allocated to intervention n = 50
Allocated to intervention n = 50
Received allocation n = 50
Received allocation n = 50
No discontinued intervention
No discontinued intervention
Survey not completed n = 32
Survey not completed
6-week postpartum n = 29
At discharge n = 33
VAS not available POD #1 n = 4
6-week postpartum n = 24
VAS not available D/C day n = 6
VAS not available POD #1 n = 3 VAS not available D/C day n = 5
A n a l y s i s
VAS POD #1 n = 47
VAS POD #1 n = 46
VAS D/C day n = 45
VAS D/C day n = 44
Pain pills n = 47
Pain pills n = 48
VAS, visual analog scale. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
The purpose of the study is to compare postoperative pain, cost, speed of closure, and patient satisfaction of Pfannenstiel skin incisions closed with traditional metallic staples vs absorbable staples after cesarean delivery. Our hypothesis is that absorbable staples will result in less pain as compared with metallic staple wound closure.
Good Samaritan Hospital in Cincinnati, OH, who were undergoing a scheduled delivery via cesarean delivery. Approval to conduct this study was obtained from the TriHealth Institutional Review Board. The study was also registered with National Institutes of Health registry of both federally and privately funded clinical trials (identifier no. NCT01198691).
M ATERIALS
Participants The cohort for this study comprised women presenting to Good Samaritan
AND
M ETHODS
A randomized, controlled trial was performed using patients recruited from
Research
Hospital for a scheduled cesarean delivery via Pfannenstiel skin incision, and who met all of the following inclusion criteria: (1) singleton gestation; (2) 18 years of age; and (3) obtained prenatal care through the Good Samaritan Hospital Obstetrics/Gynecology Resident Clinic or the maternal-fetal medicine attending private practice. Excluded from the study were those patients with a history of drug or alcohol abuse, contraindications to postoperative nonsteroidal antiinflammatory drugs or narcotics, and undergoing emergent cesarean delivery. Patients were recruited from July 2010 through May 2011. The Figure reveals the patient flowchart from enrollment to analysis.
Interventions All patients provided informed consent, and were randomized, via sealed envelopes, using a random number generator. The control group received metallic staples using a Proximate PXW35 Skin Stapler (Ethicon Endo-Surgery Inc, Cincinnati, OH) and the experimental group received subcuticular absorbable polylactic/polyglycolic acid staples using a Food and Drug Administratione approved sterile, single-patient-use stapling device. All patients received antibiotics preoperatively within 60 minutes of skin incision. The nursing staff and the patient were blinded to the type of skin closure throughout the postoperative period, and both groups of patients received identical dressings that remained in place until the day of discharge. Prior to using the device, the resident physicians and faculty received an in-service from the company representative on how to place the absorbable sutures. All data were extracted by the primary investigator from the patients’ electronic medical records in OB Trace View (Phillips, Andover, MA). Prenatal records and surveys were obtained either from the Good Samaritan Hospital Obstetrics/Gynecology Resident Clinic or the maternal-fetal medicine attending private practice. Objectives The primary outcome was pain on postoperative day 1, and on the day of
DECEMBER 2013 American Journal of Obstetrics & Gynecology
556.e2
Research
www.AJOG.org
Obstetrics
discharge. This was determined by the use of a visual analog scale (VAS) score and the total number and dose of narcotic pills taken by the patient during hospitalization. The VAS score was recorded in the medical record by the postpartum nurse during routine assessments of the patient’s incisional pain on postoperative day 1, and on the day of discharge.8 The total number and type of oral narcotics taken during the postoperative period was determined from the patients’ medical records. Ibuprofen is a self-medication available at the bedside, and therefore, was not counted. All patients were instructed to take 800 mg every 6 hours. The charts were reviewed for any evidence of wound complications, defined as a seroma, cellulitis, hematoma, dehiscence, and wound disruptions. In addition, patients were asked if they were treated for a wound complication on the 6-week postpartum patient survey. Secondary outcomes included time of skin closure, patient satisfaction, and cost. Time of skin closure was recorded by the circulating nurse, using the clock in the operating room in total seconds, and entered into the patient’s medical record. Patient satisfaction was evaluated by a survey that was administered on the day of discharge after the patient’s dressing was removed, but before staple removal, if needed, as well as at the 6-week postpartum visit. Cost was calculated by assessing the cost of the 2 stapling devices used per surgery, operating room costs of $70.00 per 1-minute increments applied to the differences in the times of skin closure between the 2 methods, and the additional costs of staple removal device and registered nurse time for the metallic staples removal (Current Procedural Terminology code 99211). After conducting a power calculation for a 2-group t test with a .050 2-sided significance level, 50 patients were included in each group to have a 90% power to detect the difference of 2.68 in the VAS score.9 For independent samples, t test was used for analyses involving continuous variables, including difference in postoperative pain between the 2 groups. The c2 (or Fisher exact test where
TABLE 1
Maternal demographics Demographic
Absorbable n [ 50
Metallic n [ 50
Maternal age, y
27.38 6.15
28.32 5.63
Race/ethnicity African American Asian Caucasian Pacific Islander
P value .427 .487
23 (46%)
22 (44%)
0 (0%)
2 (4%)
26 (52)
24 (48%)
1 (2%)
2 (4%)
Gestational age, wk
38.86 0.81
38.57 1.60
.251
BMI
36.66 8.05
34.44 7.43
.163
3 (6%)
4 (8%)
> .999
Prior abdominal surgery
44 (88%)
43 (86%)
> .999
Prior CD
41 (82%)
41 (82%)
1.000
Smoker
No. of prior CD
1.51 0.63
1.40 0.54
.406
Anesthesia type Regional
49
49
General
1
1
Intrathecal narcotic
44 (93.6%) (n ¼ 47)
48 (98.0%) (n ¼ 49)
History of Pfannenstiel incision
42 (84%)
42 (84%)
Days from CD to discharge
2.86 0.645 (n ¼ 49)
3.06 0.818 (n ¼ 50)
1.000
.357 1.000 .175
Categorical variables presented as n (%) and continuous variables presented as mean SD. Independent samples t test, 2-tailed, for continuous variables, and c2 or Fisher exact test for categorical variables. BMI, body mass index; CD, cesarean delivery. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
appropriate) was used for analyses involving categorical variables. Software (SPSS, version 19; IBM Corp, Armonk, NY) was used for all analyses.
R ESULTS Of the 100 patients enrolled in the study, 50 received the absorbable staples and 50 received the metallic staples. All patients consented and randomly assigned completed the study protocol, and there were no deviations. There were no significant differences in maternal demographic characteristics between the 2 groups (Table 1). Based on the VAS scores, there was no significant difference between the 2 groups for pain scores on postoperative day 1 or on the day of discharge. Also, there was no significant difference
556.e3 American Journal of Obstetrics & Gynecology DECEMBER 2013
between the 2 groups in the total amount and dose of oral narcotics required during the postoperative period (Table 2). Because there may be differences in efficacy between narcotic medications, only the 95 patients who were prescribed oxycodone (5 mg)/acetaminophen (325 mg) were analyzed. The time for skin closure was significantly different: 3.51 1.7 minutes for absorbable and 1.39 0.69 minutes for metallic staples, P < .001 (Table 3). The rates of wound complications between the 2 groups were comparable, with a total of 4 wound complications in the absorbable staple group, and none in the metallic staple group. These complications included: 1 hematoma, 2 cases of cellulitis, and 1 event of excessive bleeding from the subcuticular layer.
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TABLE 2
Primary outcome: pain Variable
Absorbable
Metallic
P value
VAS postoperative day 1
2.90 1.54 n ¼ 46
2.56 1.47 n ¼ 47
.279
VAS day of discharge
3.52 5.80 n ¼ 44
2.66 1.47 n ¼ 45
.338
Total no. of narcotic pills (oxycodone [5 mg]/acetaminophen [325 mg])
14 10.18 n ¼ 48
14.4 10.81 n ¼ 47
.851
Continuous variables presented as mean SD. Independent samples t test, 2-tailed, P < .05, 2-tailed test. VAS, visual analog scale score. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
Table 4 shows that the calculated cost of each device, including operating room time, device cost, and cost of removal, was $285.60 for the absorbable and $150.79 for the metallic staples. Surveys at the time of discharge and at the 6-week postpartum visit were assessed for patient satisfaction. A total of 38 initial surveys and 47 of the 6-week postpartum visit surveys were completed. When patients were asked, on their initial and 6week postpartum visit surveys, if they were satisfied with the overall appearance of their incisions, 14 of 17 of those in the absorbable staple group agreed, and 16 of 18 of those in the metallic group agreed. Again, similar results were obtained when patients were asked the same question at their 6-week postpartum visit. A total of 21 of 26 in the absorbable group and 20 of 21 in the metallic group were satisfied with the appearance of their incision. Of
the patients with metallic staples, 48% indicated that they were worried about having their staples removed.
C OMMENT Overall, our results indicate that there is no significant difference between the 2 groups in the amount of postoperative pain, both objectively and subjectively, as assessed by the VAS score, and the total dose of narcotics taken postoperatively. This differs from what has been published for cesarean deliveries4 and in the orthopedic literature.6 In the Nitsche et al4 retrospective cohort study of cesarean deliveries, the investigators found a 1.5-fold decrease in ketorolac use, but not a decrease in ibuprofen and oral narcotics. Our patients routinely have ibuprofen available as a self-medication so the number of pills that the patient took was not assessed.
TABLE 3
Secondary outcomes: wound closure Variable
Absorbable
Metallic
P value
Skin closure time (min), mean
3.51 (1.74) n ¼ 43
1.39 (0.69) n ¼ 37
< .001
Total operative time, min
50.9 (20.59) n ¼ 50
46.4 (9.7) n ¼ 48
.178
EBL (mL), mean
1038.4 (423) n ¼ 49
962.5 (119) n ¼ 46
.234
Wound complication
4 (8.1%) n ¼ 49
0 (0%) n ¼ 46
.118
Categorical variables presented n (%) and continuous variables presented as mean (SD). Independent samples t test, P < .05 Fisher exact test for categorical variables. EBL, estimated blood loss. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
Research
Overall satisfaction rates with respect to cosmesis between the 2 devices appear to be comparable based on survey results. Although this study was not designed to specifically study cosmesis, a simple question on the patient surveys indicated that patients were satisfied with the appearance of the incisions, both at the time of discharge and again at 6 weeks postoperatively. Future studies to examine this relationship are needed to effectively compare cosmesis between these devices. When cost was compared between groups, the average cost of each device, including placement and removal, was $285.60 for the absorbable and $150.79 for the metallic staples, primarily due to the longer skin closure times for the absorbable stapler. An important point to note is that the majority of the surgeons were using the product for the first time, which undoubtedly prolonged closure times. There is a significant learning curve associated with the absorbable device that most likely played a role in the longer skin closure times required for the device. As operators become more experienced with the absorbable device, a significant narrowing of the discrepancy between closure times would be expected. It is important to recognize that although the absorbable stapler is a more expensive option in our study, this is due to longer skin closure times from an unfamiliar stapling device. If with practice, surgeons were able to close the skin with either device in approximately the same time, the cost of absorbable staples would become approximately equal to that of metallic staples. The absorbable staples do eliminate the need for staple removal and eliminates patient anxiety that is associated with the removal process that almost half of the patients indicated on their surveys. Safety is also another concern when using any new skin closure technique. All 4 wound complications occurred in the absorbable group vs none in the metallic group. This discrepancy in complications could be explained by surgeon inexperience with the absorbable staple device. Although these results were not significant, future studies with greater sample size are needed to specifically look at wound complication rates between the
DECEMBER 2013 American Journal of Obstetrics & Gynecology
556.e4
Research TABLE 4
Calculated costs based on staple device Variable Device
Absorbable Metallic $40.00
$9.00
OR time for skin closure
$245.60
$97.30
Removal device
0
$3.24
RN removal
0
$41.25
Total
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$285.60
$150.79
OR, operating room; RN, registered nurse. Feese. Staple skin closure at cesarean delivery. Am J Obstet Gynecol 2013.
devices. Also, the overall cost of a stapling device will increase if the cost of caring for a wound complication is included. Strengths of the study included that it was a randomized controlled trial, and that both the patient and postpartum nurse were blinded. Also, a power calculation was performed and our recruitment goal was met to achieve a 90% power. Objectively and subjectively, we determined that the amount of postoperative pain was equal between the stapling devices.
A limitation of the study was that a nonvalidated patient satisfaction survey was used and that a relatively low response rate was achieved. Our return surveys had only a 38% response rate for the initial patient survey, and a 47% response rate for the 6-week postpartum patient survey. A meaningful conclusion of patient satisfaction cannot be drawn from this low response rate. A post hoc power analysis was conducted because the observed SD varied from the predicted SD used in the a priori calculation, and showed that power was nearly 100% to show a difference of 2.68 in the VAS score on postoperative day 1, but was only 20% to detect the small difference of 0.34 that was actually observed. Although cost remains a considerable barrier to using the absorbable skin closure technique, perhaps it could be offset by the fact that it can eliminate patient worries regarding staple removal, and skin closure times may decrease as surgeons gain more experience with the device. Despite these limitations, this study shows that postoperative pain, patient satisfaction, and wound complication rates are comparable between devices.
556.e5 American Journal of Obstetrics & Gynecology DECEMBER 2013
REFERENCES 1. Altman AD, Allen VM, McNeil SA, Dempster J. Pfannenstiel incision closure: a review of current skin closure techniques. J Obstet Gynaecol Can 2009;31:514-20. 2. Clay FSH, Walsh CA, Walsh SR. Staples vs subcuticular sutures for skin closure at cesarean section delivery: a metaanalysis of randomized, controlled trials. Am J Obstet Gynecol 2011;204:378-83. 3. Mackeen AD, Berghella V, Larsen ML. Techniques and materials for skin closure in caesarean section. Cochrane Database Syst Rev 2012;11:CD003577. 4. Nitsche J, Howell C, Howell T. Skin closure with subcuticular absorbable staples after cesarean section is associated with decreased analgesic use. Arch Gynecol Obstet 2011;284:979-83. 5. Tellis VA. Renal transplant incision closure using new absorbable subcuticular staple device. Clin Transplant 2007;21:410-2. 6. Fisher DA, Bengero LL, Clapp BC, Burgess. A randomized, prospective study of total hip wound closure with resorbable subcuticular staples. Orthopedics 2010;33:665. 7. Cross KJ, Teo EH, Wong SL, et al. The absorbable dermal staple device: a faster, more cost-effective method for incisional closure. Plast Reconstr Surg 2009;124:156-62. 8. Wong DL, Baker CM. Pain in children: comparison of assessment scales. Pediatr Nurs 1988;14:9-17. 9. Cepeda MS, Africano JM, Polo R, Alcala R, Carr DB. What decline in pain intensity is meaningful to patients with acute pain? Pain 2003;105:151-7.