A Predictive Model for Primary Closure Lengths in Mohs Surgery Based on Skin Cancer Type, Dimensions, and Location.

BACKGROUND: Surgical scar length is a common concern among patients undergoing Mohs micrographic surgery (MMS).

OBJECTIVE: This study evaluates 3 metrics of preoperative lesion size to determine which correlates best with primary linear closure lengths for nonmelanoma skin cancers (NMSCs) treated with MMS. This metric is then used to develop predictive models for linear closure lengths in 10 different anatomical regions.

MATERIALS AND METHODS: A retrospective study of 4,049 NMSCs treated with MMS and repaired with primary linear closure was conducted. Primary closure lengths were plotted against preoperative lesion circumference, area, and short axis length. Linear regression analysis was performed.

RESULTS: Preoperative NMSC circumference correlated best with closure length. Twenty-one of the 28 regression models had coefficients of determination (R) above 0.5. Closure lengths increased by 0.52 to 1.1 mm, depending on location, for every millimeter increase in preoperative NMSC circumference.

CONCLUSION: Preoperative lesion circumference is directly proportional to primary closure length and is a better indicator of closure length than preoperative area and short axis for MMS of NMSCs. Closure lengths located on the nasal tip, supratip, or periocular areas are most sensitive to differences in NMSC size. These data might aid Mohs surgeons with preoperative planning for wound reconstruction and patient counseling.