[The moat technique. A two-step surgical technique for extensive basal cell carcinomas of the lip].

Surgery of large basal cell carcinomas (BCC) in problematic locations is sometimes challenging. A two-step surgical treatment of extensive BCC of the upper lip with the moat technique as an alternative to temporary wound closure will be illustrated using the example of two patients: In the first step, only the safety margin around the tumor is removed. After micrographic examination proves the lateral margins to be tumor-free, the tumor itself with all layers of the upper lip is removed in a second step. The defect is then closed with advancement flaps. If tumor resection does not involve all layers, the histopathologic interpretation of the base is first possible after complete surgical closure. The moat technique offers several advantages: The infection risk is minimized and the patient can eat and drink with an intact lip while resection margins are processed overnight. Tumor-free tissue is spared through the step-by-step procedure; the extent of plastic surgery is thus reduced and good functional and cosmetic results can be achieved. In addition, the perioperative period is less complicated.