Interrupted subcuticular suture spacing during linear wound closures and the effect on wound cosmesis: a randomized evaluator-blinded split-wound comparative effectiveness trial

Abstract Background Surgical reconstructions following Mohs micrographic surgery and standard surgical excisions are often closed with two layers of sutures: a deep subcuticular layer and a superficial cuticular layer. Some surgeons feel the need to place many deep sutures in order to reduce tension on cuticular sutures, as they believe this may decrease incidence of track marks and dehiscence, and lead to better cosmetic outcomes. However, others feel that a higher number of subcuticular sutures increases the risk of a suture reaction, which leads to patient anxiety and poorer wound cosmesis. To our knowledge, there are no studies published on the effect of subcuticular suture spacing on wound cosmesis. Objectives To determine whether suturing with 1-cm interval subcuticular sutures results in better cosmetic outcomes than suturing with 2-cm interval subcuticular sutures. Methods Fifty patients were enrolled in a randomized clinical trial using a split-wound model, where half of the wound was repaired with sutures spaced 2 cm apart and the other half was repaired with sutures spaced 1 cm apart (ClinicalTrials.gov identifier NCT03327922). Both the evaluators and patients were blinded as to which side received which treatment. The scar was evaluated 3 months post-surgery by two blinded observers and the patients themselves using the Patient and Observer Scar Assessment Scale (POSAS), a validated scar assessment instrument. Results The total mean POSAS score for observers for the sides that received 1-cm interval subcuticular sutures and the sides that received 2-cm interval subcuticular sutures did not differ significantly at 3 months (P = 0·34). There was also no significant difference in the patient assessment scale score between the two sides at 3 months (P = 0·084). Conclusions We found that 1-cm suture spacing was not significantly associated with improved overall cosmetic outcome compared with 2-cm suture spacing when evaluated by blinded observers or the patients themselves. Our results support the use of either interval. What is already known about this topic? Surgeons have differing opinions on the ideal frequency of subcuticular sutures for optimizing cosmetic outcomes and minimizing suture reactions. The effect of subcuticular suture spacing on wound cosmesis has not been previously explored in the literature. What does this study add? There was no significant difference in cosmetic outcome between 1-cm suture spacing and 2-cm suture spacing when evaluated by blinded observers and patients. Dermatology surgeons can use 2-cm suture spacing for increased efficiency, without significantly different cosmetic outcomes, detected by blinded observers and patients.