A Prospective Study to Compare the Cosmetic Results of Sutures With Different Absorption Rates for Lower Abdominal Incision

Data from clinical trial and the previous study have demonstrated that wedge excision combined modified buried vertical mattress suture (WE-MBVMS) provides better aesthetic outcomes than traditional ways. As an effectively tension reducing, precisely edge everting and easily performing technique, WE-MBVMS has the following characteristics distinguishing it from other methods: (1) The edge of the incision was excised in a wedge size to guarantee a fully eversion in the edges of the incision; (2) And the stitch embed in the dermis as long as possible to recruit dermal tissue as much as possible in the suture loop, from which a sufficient skin eversion accompanied with visible skin folds is formed.

After the above operation, tension of the incision is effectively reduced and reserved to antagonist the consistently existing tension for a certain time, which is the core of WE-MBVMS in inducing slight scars. Although WE-MBVMS possesses the ability of confronting tension for a long time, the absorbable suture used during the WE-MBVMS decided the length of the tension reserving time. It is known that the period of scar molding is as long as 6-12 months, during which tension reducing contributes a lot in scar suppression. Hence, selecting appropriate material for the WE-MBVMS to achieve enough support for tension reducing of the incision might consequently lead to ideal scar suppression.

Nowadays, various kinds of absorbable sutures can be used in intradermal suture, among which PDS™ (polydioxanone) and Vicryl™ (polyglactin) is most commonly used. With the tension holding time of 90 days and 30 days, respectively, it is easy to relate them to different scar suppressing ability. Considering the crucial role of reducing tension played in suppressing scar and that nonabsorbable suture, also used in intradermal suture, provide prolonged dermal support, the researchers also employed polyester nonabsorbable suture in the WE-MBVMS . Although the ability of polyester suture in reducing tension will not be disturbed by its broken down by the body, tissue cutting and displacement will happen under the continuous action of external force over time. It follows that the efficiency of tension reduction and tissue eversion brought by polyester is prolonged but not permanent.

In this study, the lower abdominal incision will be selected which induced by harvesting autogenous skin grafts for wound repair to perform the comparison of the above three sutures. Because the donation causes incision, which leaves scar in the donor site that is mostly neglected by surgeons but concerned by patients. Besides, the hypogastrium is one of the important aesthetic units, thus scar is aesthetically undesirable or symptomatic8. Moreover, autogenous hypogastric skin graft, as an important skin donor site, is commonly used by plastic surgeons. Through comparing the cosmetic results of scars achieved by materials with different tension holding time, the researchers will further understand the duration of tension-reduction required for optimal scar inhibition and get a reference for suture selection. Taken together, a feasibility trial is required to produce more evidence for a fully powered randomised controlled trial (RCT).

This is a feasibility, single-center RCT with 35 patients aiming to compare the scar of the hypogastric incision sutured by three different-absorption-rate sutures with WE-MBVMS. The incision induced by donating skin grafts is evenly divided into three segments, each segment randomly uses one of three different sutures randomly allocated by the SAS (V.9.4) statistical software. The feasibility of this study will be assessed by the primary outcomes, including patient and clinician enrolment refusal as well as their reasons, reasons for ineligibility, recruitment ratio, retention and withdrawal at each follow-up point (1, 3, and 6 months), reasons for withdrawal, integrity of collected data and adverse event rates. Secondary outcome measures of the cosmetic outcome of scar will help shape future fully powered RCT by formulating the sample size.