Comparative analysis of one-step and two-step full thickness skin grafting and secondary intention healing for skin defects after surgical management of plantar malignant melanoma

Plantar malignant melanoma is largely managed surgically, particularly in its early stages. However, the plantar region has a lower survival rate of skin grafts than other regions. Furthermore, complete wound healing occurs over a long period of time, postoperatively. Thus, in this study, we retrospectively analyzed the use of skin grafts to reconstruct skin defects, as postoperative complications of plantar malignant melanoma. Forty-nine patients, (23 males, 26 females; mean age 70.4-years) underwent excisional surgery for plantar malignant melanoma at our hospital, between March 2018 and December 2022. The time from initial surgery to wound healing was analyzed, using a multivariate Cox proportional hazards model, to identify related factors. We excluded cases with lesions in non-weight-bearing areas and cases with segmental layer grafts, based on multivariate analysis, to eliminate bias when comparing a one-step resection and reconstruction technique to resection followed by waiting for granulation to occur before reconstruction. Patients were categorized into three cohorts. The first and second cohorts had undergone one-step and two-step skin grafting, respectively. Patients in the third cohort underwent secondary intention healing without skin grafting. The results revealed that the factors associated with wound-healing time included a defect size of >1800 mm², in addition to two-step and split-thickness skin grafting. Therefore, Kaplan–Meier curves were constructed across the three cohorts, based on the data of 37 patients. Nine cases of non-weight-bearing areas and three cases of split-thickness skin grafts were excluded from the original total of 49 patients. The median times from the initial surgery to wound healing were 14.6, 12.0, and 21.9 weeks for the one- and two-step skin grafting and secondary intention healing cohorts, respectively. A statistically significant difference in the treatment time between the skin grafting and secondary intention healing cohorts was observed (p < 0.001) Moreover, a statistically significant difference in the treatment time between the one- and two-step skin grafting cohorts was noted (p = 0.046). Thus, two-step skin grafting after surgical treatment for plantar malignant melanoma may shorten the overall treatment duration by allowing granulation to occur.