Bipedicled Dartos Myocutaneous flap for perianal defects – A simple flap with immense potential

摘要

Perianal defects pose a particular challenge for reconstruction to the Plastic Surgeon. These defects, depending on their size, have been reconstructed using local advancement, rotation and transposition flaps or regional flaps. We describe the use of scrotal myofasciocutaneous (Dartos) flap for reconstruction of a peri-anal defect. The use of this simple yet robust flap for peri-anal reconstruction is rare. We propose the use of dartos flap as a viable alternative for challenging peri-anal reconstructions. Introduction Peri-anal defects largely result following surgical resection for a variety of malignant and non malignant conditions. Advanced carcinomas of the rectum, vulva, anal squamous cell carcinoma or extra-mammary Paget’s disease require extensive resection and result in large peri-anal defects.. Some non cancerous conditions requiring wide perianal resections include pilonidal sinuses, hydradenitis and very rarely traumatic wounds.The nature of the peri-anal reconstruction is determined by a number of patient factors and clinico-pathologic factors. Patient factors include age, sex, nutritional status, existing co-morbidities, patient’s desires and expectations. Clinico-pathologic factors include the nature of the underlying pathology, local infection, nature of local available tissue, previous radiotherapy and size and extent of the defect.There are a number of possible options for closure of perianal defects, these include local flaps, regional flaps and rarely free flaps. Occasionally skin grafts may be used but usually these have a poor outcome in the perineum. In this paper we discuss the use of dartos flap in a patient with a peri-anal defect secondary to fistula and wound breakdown following ultra low anterior resection due to adenocarcinoma of the rectum. Case A 57 year old male patient was referred by colorectal surgeons for assistance in reconstructing the peri-anal defect and closure of colo-anal fistula. This patient was diagnosed a year ago with a low rectal carcinoma and from the onset was keen on retaining the anal sphincter function. An ultra low sphincter sparing abdomino-perineal resection resulting in coloanal anastomosis with a diversion loop colostomy was undertaken. Subsequently, the patient became septic and sustained an anastomotic breakdown in the 12 to 3 o’clock position with the development of a neo-recto perineal fistula. Recurrent efforts to repair this fistula using both an intra- anal approach and mobilisation of the peri-anal skin flap were unsuccessful and resulted in persistent fistula with an approximately 6cm x 4cm peri- anal defect extending intra-anal (Figure 1).