Randomized double-blind trial comparing the cosmetic outcome of cutting diathermy versus scalpel for skin incisions

Background: Controversy exists about whether cutting diathermy for skin incisions leads to a cosmetically inferior scar. Cosmetic outcomes were compared between skin incisions created with cutting diathermy versus scalpel. Wound infection rates and postoperative incisional pain were also compared. Methods: This was a randomized double-blind trial comparing cutting diathermy and scalpel in patients undergoing bowel resection. Scar cosmesis was assessed at 6 months after surgery by a plastic surgeon and a research associate using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). Patients also used POSAS to self-evaluate their scars. Wound infections within 30 days were recorded, and incision pain scores were measured on the first 5 days after operation. Results: A total of 66 patients were randomized to cutting diathermy (31) or scalpel (35). At 6 months, there was no significant difference between the diathermy and scalpel groups in mean(s.d.) VSS scores (4.9(2.6) versus 5.0(1.9); P=0.837), mean POSAS total scores (19.2(8.0) versus 20.0(7.4); P=0.684) or subjective POSAS total scores (20.2(12.1) versus 21.3(10.4); P=0.725). Neither were there significant differences in wound infection rates between the groups (5 of 30 versus 5 of 32; P=1.000). Pain scores on day 1 after operation were significantly lower in the diathermy group (mean 1.68 versus 3.13; P=0.018), but were not significantly different on days 2-5. Conclusion: Cutting diathermy is a cosmetically acceptable technique for abdominal skin incisions. There is no increased risk of wound infection, and diathermy may convey benefit in terms of early postoperative wound pain. Registration number: NCT01496404 (http://www.clinicaltrials.gov).