Abdominal Perineal Resection with Colostomy

Chapter 26 Abdominal Perineal Resection with Colostomy







OPERATIVE PROCEDURE





Perineal Dissection


Upon completion of the abdominal dissection, the surgeon must reposition himself or herself for the perineal dissection. An elliptical incision is made around the anus, approximately 2 to 3 cm from the anal verge (Fig. 26-1). Once the skin is incised, the dissection is greatly facilitated by the use of a self-retaining retractor (Fig. 26-2). The incision is then carried deeper into the ischiorectal fossa bilaterally (Fig. 26-3). No vital structures are located in the posterior or lateral positions, so dissection in this area is safe and should be continued more deeply using electrocautery. The inferior rectal artery does pass through the ischiorectal fossa and may result in some minor bleeding. This artery can usually be controlled with electrocautery but does occasionally require ligation. As the dissection is carried posteriorly, there is a tendency for the operating surgeon to travel too far and get behind the coccyx (Fig. 26-4). Therefore, careful palpation of the coccyx is critical to guide the surgeon’s dissection above the coccyx. Once the coccyx is clearly identified (Fig. 26-5), a fibrous band extends from the coccyx in the midline position. This is the anococcygeal ligament and needs to be divided. The surgeon is now ready to enter the peritoneal cavity just above the coccyx. This is best done with an assistant placing a hand behind the rectum all the way to the coccyx from the abdominal cavity. Then the operating surgeon should be able to palpate the assistant’s finger. Mayo scissors are then used to poke through the pelvic floor, just above the coccyx (Fig. 26-6). This hole is widened, which allows the operating surgeon to insert a finger into the peritoneal cavity and hook the levator ani muscles. Using electrocautery, these muscles can be divided in both directions (Fig. 26-7). Once 75% of this dissection is complete, the top of the rectum can be grasped and pulled through the perineal defect (Fig. 26-8). This helps define the anterior plane of dissection, which can be the most challenging. With a hand behind the rectum, the anterior plane between the rectum and the prostate or the vagina is developed (Fig. 26-9). In a man, palpation of the Foley catheter can help define this plane (Fig. 26-10). In a woman, a finger in the vagina can be advantageous. The specimen is finally freed and removed. The perineal wound is then closed, using several layers of an absorbable suture, and the skin closed with a subcuticular stitch.












Jun 21, 2017 | Posted by in GENERAL SURGERY | Comments Off on Abdominal Perineal Resection with Colostomy

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