Absorbable versus nonabsorbable sutures for subcuticular skin closure of a transverse suprapubic incision

A transverse suprapubic (Pfannenstiel) incision is widely used during open gynecologic surgery and cesarean delivery, and is associated with a better cosmetic result [1]. It was reported that 73.9% of obstetricians in the United Kingdom closed with a subcuticular suture after cesarean delivery [2]. Alderice et al. [3], in a Cochrane Review of skin closure at cesarean delivery, included only one trial (66 women) that compared subcuticular absorbable suture with staples, and which showed more favorable results with the former. We hypothesized that an absorbable suture that does not require removal will be associated with greater patient satisfaction. A randomized study was performed to compare absorbable monofilament poliglecaprone 25 (Monocryl, Model W 3650; Ethicon, Somerville, NJ, USA) with nonabsorbable monofilament polypropylene (Prolene, Model W 8630; Ethicon, Somerville, NJ, USA) suture. Ethical approval was obtained and written consent was provided by the participants. Women with no abdominal scar who were scheduled to undergo benign gynecologic surgery or cesarean delivery using a Pfannenstiel incision between April 2006 and December 2007 were recruited to the study. Randomization was generated by a computer in blocks of 10. Sealed and numbered opaque envelopes containing suture packets were prepared. The envelopes were kept in the operating theatre and assigned in order. Participants assigned to the nonabsorbable suture group were told that removal would be required. Surgery was performed according to our institution's standard practice. Skin closure was performed in a standardized fashion with a continuous subcuticular technique. Standard wound management was advised in both groups of women. The participants were assessed at 1 and 4 weeks. The participants' wound experience was the main outcome and was measured using a 10-point visual analogue scale (VAS; 0 = complete dissatisfaction to 10 = complete satisfaction). Assessment of superficial surgical site infection was made by an observer using established criteria [4]. Nonabsorbable sutures were removed at week 1 without anesthesia or analgesia. The VAS score was obtained after suture removal to incorporate this aspect into the participants' experience. Secondary outcome measures were assessed using a simple questionnaire (yes or no responses) to ascertain participants' satisfaction with wound appearance, pain, discharge, itch, and operation to discharge interval. Sample size calculation to detect a 1 point difference in mean VAS assuming a standard deviation of 2, setting alpha at 0.05, and power at 0.8 indicated that 64 women were needed in each arm. Analysis was performed based on intention to treat. Data were analyzed using SPSS version 15 (SPSS, Chicago, IL, USA). P < 0.05 in any test was considered significant and all tests were 2-sided. A total of 107 women were randomized to the polypropylene (nonabsorbable) group and 106 to the poliglecaprone (absorbable) group. All participants underwent their allocated treatment. The characteristics of both groups of women were similar (Table 1). In all, 64/213 women (30%) did not attend for follow-up. The outcomes are shown in Table 2. There was no difference in outcome except for wound itch at week 4: 0/54 (0%) for polypropylene suture versus 4/47 (8.5%) for poliglecaprone suture (P = 0.04). Repeated measures analysis of variance for VAS indicated that there was no change in VAS over time (P = 0.15) and no difference between the groups over time (P = 0.35). No removal of an absorbable suture was needed, and no wound resuturing was required in any participant. Because poliglecaprone 25 is completely absorbed at 3 months it is plausible that a partially absorbed suture at 4 weeks may have caused skin irritation and wound itch. Because of the number of secondary outcomes analyzed and significant dropouts by week 4 this finding should be interpreted with caution. Follow-up was not attended by 30% of participants, and fell from 68% at week 1 to 46% at week 4. This is because many of the participants had returned home for traditional confinement: a reflection of local custom and recent urban migration. At week 1, more women assigned to the poliglecaprone suture group did not attend follow-up (43/106 [41%] vs 25/107 [23%]; P = 0.008). We postulate that participants with an absorbable suture were demotivated from attending because they perceived that there was no real need to attend the appointment. A survey of cesarean delivery practices in the United Kingdom showed that over 99% of respondents used a Pfannenstiel incision and, for skin closure, the following were used: polypropylene (41.1%), polyglactin (17.5%), polyglycolic acid (13.5%), staples (10.4%), clips (6.1%), and poliglecaprone 25 (5.2%) [2]. A 3-arm study of absorbable polydioxanone suture for skin closure at cesarean delivery concluded that intracutaneous closure of the Pfannenstiel incision produced better cosmetic results than lower midline incisions closed by either intracutaneous or percutaneous suturing [1]. These findings do not provide information on the best suture material to use. Our study has some limitations. We did not attempt to blind the participants and the dropout rates were uneven at week 1 and high at week 4. Absorbable and nonabsorbable sutures have a similar short-term outcome. An absorbable suture does not require removal and may be preferred.