Surgical management of lipomas: Proposal of the Z-incision design and surgical algorithm based on tumor size

Surgical excision is the treatment of choice for lipomas. However, linear incision methods or minimal extraction techniques often do not provide a sufficient surgical view. Therefore, removing large lipomas is often difficult. To present the Z-incision and half Z-incision designs for lipoma extraction, this retrospective study analyzed lipomas surgically excised at our institution between September 2015 and December 2018. The area of surgical field exposed by the Z-incision versus that exposed by the linear incision was calculated using a schematic model. Cure rate, complications, and surgical field area were investigated. A total of 84 lipomas were included. A Z- or half Z-incision was used to treat 30 lipomas, while a linear incision was used to treat 54 lipomas. The mean diameter of the mass in the Z- or half Z-incision group was 47.7 mm (range, 15-160 mm), larger than that in the linear incision group (25.5 mm; range, 7-59 mm) (p < .001). The Z-incision involved making rectangular windows by lifting 2 triangular flaps. According to our mathematical model, the Z-incision provided a larger surgical field area than that provided by the linear incision based on stretched angles (1.81 times larger at 30° and 3.14 times larger at 15°). The Z- and half Z-incisions were successfully performed in all but 1 lipoma (29 lipomas, 96.7%). There was 1 lipoma that resulted in postoperative complications (seroma, 3.3%). The Z-incision design can be a useful alternative technique for the extirpation of lipomas, especially large lipomas. Here, we proposed a surgical algorithm for lipoma surgery based on tumor size.