The ileal pouch anal anastomosis (IPAA) procedure, also known as ileoanal anastomosis or restorative proctocolectomy, was developed in the 1970s by Sir Alan Parks in London. It was offered as an alternative to performing a Brooke end ileostomy for patients who underwent total colectomies for a variety of diagnoses, most commonly inflammatory bowel disease.^1,2 The Parks’ procedure offered important advantages over the previously used ileoanal end-to-end anastomosis (without a pouch reservoir), which resulted in poor functional outcomes, including higher fecal frequency, urgency, and incontinence rates.^3,4,5 With the addition of a pouch that serves as a lower pressure reservoir, patients are offered the quality-of-life advantage of restoring the continuity of their intestinal tracts, which obviates the need for permanent abdominal wall stomas (and ostomy appliances). When performed on properly selected patients, high rates of fecal continence and patient satisfaction can be expected.^6,7

Over the past several decades minor modifications in the IPAA procedure have been suggested; however, the basic principles of the surgery have been maintained. Parks’ original reservoir was created as an S-shaped (or 3-limbed) ileal pouch.² Alternatives to the 3-limbed S-pouch are the 4-limbed W-pouch and the 2-limbed J-pouch (Figure 15-1). Because fecal continence rates are equal in all the pouch designs, and the 2-limbed approach offers the greatest amount of surgical ease and a lower complication rate, the J-pouch ileoanal anastomosis is most commonly used and is our preferred technique. Other modifications have included the addition of an anorectal mucosectomy (important for primary colonic disorders such as colon cancer, polyposis, or inflammatory bowel disease) and the use of hand-sewn versus stapled techniques.^8,9,10 We believe that the most appropriate technique for patients who undergo an IPAA following radical pelvic resections for gynecologic cancers is a stapled ileal J-pouch anal anastomosis. It is a complex procedure that should be performed by experienced surgeons.

The IPAA is most commonly performed after total colectomy for patients with ulcerative colitis or familial adenomatous polyposis.^6,11,12 Although Crohn disease is a relative contraindication to performing this procedure due to concerns for the development of Crohn enteritis and higher risks for pouch complications, patients with Crohn disease can be cautiously offered this option if total colectomy is required.^13,14,15 Toxic megacolon is another indication for colectomy and IPAA.¹⁶ Patients with colon cancer may also be offered this restorative procedure following colectomy if appropriate counseling with regard to the potential risk of recurrent cancer to the remaining bowel is provided.^17,18,19

There is very little published data with respect to the use of the IPAA in patients who undergo radical surgical procedures for gynecologic cancers.²⁰ Although total (or subtotal) colectomy is rarely indicated for gynecologic cancer resections, selected patients with advanced ovarian, fallopian tube, peritoneal, or endometrial carcinomas may benefit from radical cytoreductive surgeries that include extended colectomies.^{20,21,22 and 23} Such surgical procedures are performed with curative intent in well-selected patients. In most cases, resection of the entire rectum below the pelvic peritoneal reflection is not necessary to achieve the goal of completely debulking visible metastatic disease. Therefore, subtotal—rather than total—colectomy is usually employed in such instances when visible cancer involves the serosal surfaces of all segments of the colon. If complete surgical cytoreduction is achieved, which is associated with a relatively high rate of survival, it is reasonable to perform IPAA to provide these women with restored bowel continuity and maintenance of quality of life.

Superior Mesenteric Artery

The superior mesenteric artery (SMA) arises from the aorta behind the inferior edge of the pancreas and crosses over the duodenum anteriorly (where the duodenum transitions from its third to its fourth segment) to enter the root of the small bowel mesentery. The superior mesenteric artery trunk extends toward the terminal ileum at a location approximately 15 to 20 cm proximal to the cecum. At this location it forms an anastomosis with a branch of one of its own arterial branches—the ileal branch of the superior mesenteric artery. Prior to (and more proximal to) joining the ileal branch of the ileocolic artery, the superior mesenteric artery gives rise to a dozen or so jejunal and ileal branches, which subsequently anastomose to form arcades, which then give rise to the vasa recta, that provide the capillary blood supply to the small intestine.

Ileocolic Artery

The ileocolic artery typically branches from the superior mesenteric artery approximately 3 to 5 cm from its origin and travels within the small bowel mesentery toward the junction of the ileum and cecum. As described above, one of its terminal branches is the ileal branch which doubles back to travel proximally through the ileal mesentery to anastomose with the superior mesenteric artery. The ileal branch of the ileocolic artery travels parallel to and approximately 3 to 4 cm from the serosal surface of the ileum. It provides the terminal ileum with its blood supply via the vasa recta. Knowing this blood supply is imperative to accomplishing an adequate mobilization of the small bowel to ensure a tension-free pouch-anal anastomosis (Figure 15-2).

Duodenum, Pancreas, and Surrounding Structures

On occasion, when additional mobilization of the small bowel is required, a Kocher maneuver may be performed. When utilizing this maneuver, an understanding of the anatomy surrounding the first 3 segments of the duodenum and its neighboring retroperitoneal structures is needed. The first part of the duodenum arises from the gastric pylorus to travel toward the right and posteriorly. The second and third segments travel inferiorly and then toward the left and are overlapped by the head of the pancreas. At the distal end of the third segment of the duodenum (where it becomes the fourth and final ­segment), the superior mesenteric vessels can be found crossing anteriorly. It should be recognized that the bile duct passes posterior to the first part of the duodenum to join the pancreatic duct where they empty into the duodenal (or hepatopancreatic) ampulla in the medial aspect of the second part of the duodenum. The vena cava and aorta are located posterior to the first 3 parts of the duodenum and the head of the pancreas. At this level the celiac trunk arises from the aorta posterior to the superior edge of the pancreas and the superior mesenteric artery arise between the posterior edge of the pancreas and the third and fourth segments of the duodenum.

Extent of Disease

Although it is well established that there is no preoperative imaging test that accurately details the extent of disease for patients with metastatic gynecologic carcinomas, it is advisable to establish whether the disease is confined to the peritoneal cavity prior to attempting a complete and radical cytoreductive surgery in most situations. On our service, ­preoperative computed tomography (CT) of the chest, abdomen, and pelvis is obtained. If thoracic metastases are identified, then we would advocate a maximal thoracic and intraperitoneal cytoreductive effort on selected patients, however, would not recommend an IPAA because there are not enough published data to establish that survival rates are as good as with complete cytoreduction of intraperitoneal disease alone. If preoperative imaging does not identify metastatic disease beyond the peritoneal cavity and intraoperative assessments determine that an extended colectomy is necessary for complete cytoreduction, then the option of performing IPAA is entertained.

Performance Status

For patients undergoing radical resections with or without reconstructive surgical procedures such as the ileal pouch anal anastomosis, outcomes are directly related to preoperative performance status.^22,24 In addition to evaluating the immediate preoperative performance status, we also inquire about the performance status 1 month prior to presentation. IPAA procedures are considered for women who have an immediate preoperative Gynecologic Oncology Group performance status of 0 to 1. Although there is no validation to the predictive value of a remote performance status, in our experience patients with immediate preoperative performance statuses equal to 1 who had a 1-month preoperative performance status equal to 0 have outcomes similar to those with immediate preoperative performance statuses equal to 0.

Medical and Nutritional Status

Blood work, including a comprehensive metabolic panel and complete blood count, are obtained. Electrolyte derangements and anemia are corrected as needed. Medical and cardiac clearance is obtained on selected patients, depending on their medical history and current well being. If the patient is malnourished with albumen levels less than 2.0 mg/dL, then perioperative nutritional counseling is recommended and the possibility of nutritional supplementation and total parenteral nutrition in the postoperative period is discussed (although it is not necessary for the pouch anal anastomosis procedure specifically). Due to the catabolic nature of advanced malignant disease, it is usually not effective or advisable to delay surgery to attempt to restore nutritional status preoperatively in these patients.

Anal Sphincter Competence

Although anodynamic testing can be utilized to document appropriate anal sphincter pressures and continence, it is not possible to accurately select those patients who will require subtotal colectomies as part of their radical gynecologic cancer procedure. Therefore, a simple history of bowel function and fecal continence along with an interactive rectal examinationis performed on all gynecologic cancer patients in the ­preoperative setting. This will determine with reasonably good accuracy which patients have adequate sphincter competence when considering an IPAA as part of their reconstruction after radical surgery.

Bowel Preparation and Enterostomal Therapy Consultation

A complete mechanical bowel preparation is recommended prior to surgery that may include colon resection with or without IPAA. Appropriate prophylactic antibiotics should be administered preoperatively and may be continued up to 23 hours postoperatively at the discretion of the surgeon. The combination of subcutaneously administered heparin and pneumatic compression stockings are used for deep venous thrombosis (DVT) prophylaxis perioperatively. Because the decision to create an IPAA is ultimately made at the time of surgery and since the procedure is frequently performed in 2 stages, it is beneficial to consult the enterostomal therapist to appropriately counsel the patient about life with a stoma and to mark the abdomen for temporary or permanent stomas dependent on intraoperative determinations.

Mobilization of the Small Intestine

The peritoneal pattern of metastatic spread of adnexal, peritoneal, and endometrial adenocarcinomas rarely involves the anus or rectum below the pelvic peritoneal reflection. Therefore, if the serosal surfaces of the cecum, ascending, transverse, and descending colon are involved with substantial metastases, a subtotal colectomy should adequately remove all visible disease without resecting the anus or significant length of the extraperitoneal rectum. If a subtotal colectomy is required for maximal cytoreduction, then other radical procedures are likely to be needed as part of the same surgical effort. Upon completion of the tumor-resection-phase of surgery, if the colon was removed and the patient is deemed a reasonable candidate for reconstructive procedures, then the ileal J-pouch anal anastomosis is considered.

The ileal pouch will be constructed from the distal 30 cm of the terminal ileum, creating a 15-cm long reservoir with double the circumference of the ileum. The distal (or efferent) end of the pouch will be anastomosed to the rectum (or anus). By grasping the ileum 15 cm from its distal end with an atraumatic clamp (such as a Babcock) the segment can be pulled deep into the pelvis to the rectal stump to evaluate the feasibility of establishing a tension-free anastomosis. In some instances, the distal loop of terminal ileum falls easily into the pelvic hollow, requiring no further mobilization. However, if this is not the case, there are several maneuvers that can facilitate the mobilization needed to perform an anastomosis without tension.

The small bowel mesentery should be mobilized by dividing its right-sided peritoneal attachments all the way to and including the junction of the mesenteric root to the third part of the duodenum. The 2 most obvious lines of tension are (1) the mesentery along the path of the ileocolic artery and (2), more proximally, along the path of the superior mesenteric artery. When the mesentery is transilluminated, these 2 vascular bundles can be visualized. As discussed previously, the distal ileum is supplied by the vasa recta arising from the ileal branch of the ileocolic artery, which connects the ileo colic artery to the distal end of the superior mesenteric artery in the mesentery approximately 3 to 4 cm below the ileum. Due to this arterial connection, either the ileocolic or the superior mesenteric vessels (but not both) can be sacrificed without compromising the terminal ileum (see Figure 15-2A).

With gentle traction on the ileum 15 cm from its distal end, the primary point of tension may be a short mesentery restricted by the superior mesenteric vascular supply. In this case, the superior mesenteric artery is identified using transillumination. It is divided and ligated distal to its last jejunal branch and a window is made in the mesentery by dividing it perpendicular to the axis of the superior mesenteric artery (see Figure 15-2B). By doing this the vascular connections between the jejunal and proximal ileal arcades, the distal superior mesenteric vessels, and the ileal branch of the ileocolic vessels remains intact to preserve the vascular integrity of the terminal ileum. Prior to dividing the superior mesenteric vessels, the integrity of the ileocolic artery and the vascular connections is tested by placing a bulldog clamp on the superior mesenteric artery for at least 5 minutes. By dividing the superior mesenteric vessels, an additional 5 cm of length may be provided to the ileal mesentery facilitating adequate mobilization for a tension-free anastomosis.

More commonly, the most obvious point of tension in the ileal mesentery is along the path of the ileocolic vasculature. In this case, the ileocolic vessels are divided proximal to the ileal branch. Once the ileocolic vessels are divided and ligated, the mesentery below and parallel to the ileal branch of the ileocolic artery is divided toward the superior mesenteric ­vessels (see Figure 15-2C). The mesentery is divided with either the LigaSure or a linear stapling device with 2.0-mm staple size. Either of these tools provides excellent hemostasis and prevents the bunching of suture-ligated mesenteric pedicles, which can shorten the small bowel length and prohibit maximum mobilization. This maneuver allows for mobilization of the distal terminal ileum providing approximately 3 cm of extension toward the pelvis.