Anatomic variations in retaining ligaments during minimally invasive resection of subcutaneous lipomas.

Objective: Lipomas are common, benign tumors usually located in the subcutaneous tissue. The "one-inch method" is a minimally invasive technique for resecting large subcutaneous lipomas through a one-inch incision after blunt dissection of the lipoma from its peripheral retaining ligaments. The limitations of this method are currently unclear.

Materials and methods: We assessed twenty-five patients with large lipomas, defined as a tumor diameter greater than 5 cm. The location of the lipoma was at the shoulder in fifteen patients, the extremity in six patients, and the torso in four patients.

Results: The mean operative time for all lesions was 28.3 minutes, with a mean time of 25.9 minutes for lipomas at the shoulder, 21.8 minutes for the extremities, and 47.0 minutes for the torso. We classified patients into three groups according to operative time: the short group (10-29 min), middle group (30-49 min), and long group (50-70 min). For lipomas of the shoulder, there were eleven patients (73%) in the short group, three patients (20%) in the middle group, and one patient (7%) in the long group. For lipomas of the extremity, the groups contained five patients (83%), one patient (17%), and no patients (0%), respectively. For lipomas of the torso, the groups contained one patient (25%), no patients (0%), and three patients (75%), respectively.

Conclusions: Lipomas of the torso require a longer operative time than those of the shoulder or extremity; this difference could be due to the number of retaining ligaments present, which is reportedly higher in the back than in the anterior or side body. Lipomas of the back are less amenable to the one-inch method, and posterior shoulder lipomas may take more time than those at other parts of the shoulder or at the extremities.