Introduction and Historical Perspective
The Indiana pouch has become one of the most popular forms of catheterizable continent urinary diversions over the past 3 decades, serving a purpose for patients desiring a nonappliance diversion and who are not candidates for bladder replacement or are averse to some of the potential drawbacks, such as daytime and nighttime incontinence or urinary bother. The Indiana pouch continent urinary diversion uses the right colon as a reservoir while using reinforcement of the ileocecal valve for continence and a plicated segment of terminal ileum as a catheterizable efferent limb. Although the Indiana pouch has become the most common form of continent catheterizable urinary diversion, review of initial attempts of ileocecal continent reconstructions may serve as an understanding of the reconstructive changes that lead to its final form as we appreciate it today.
Use of the cecum as a continent reservoir dates back to the early 1900s, when Verhoogen experimentally used the ileocecal segment for urinary diversion in 1908. In his description, the cecum was used as a reservoir and the ileocecal valve as the antireflux mechanism for the ureteral anastomoses into the terminal ileum, and the appendix was brought out as a nontunneled catheterizable stoma. Further attempts at continent urinary diversions were abandoned in the mid-1920s, in large part because of reporting of increased complications with the available diversion at that point in time.
Consequently, work on the continent urinary reservoir was abandoned through 1950, at which point Gilchrist reported on the use of the ileocecal segment to achieve continence via an abdominal catheterizable stoma. In Gilchrist’s technique, the cecum was used as a reservoir, and the ureters were tunneled submucosally into the cecum to achieve antireflux. Continence relied on the need of resistance of the ileocecal valve, the antiperistaltic action of the terminal ileum, and tunneling of the ileal segment to the abdominal wall in an oblique fashion. Lack of reproducibility of Gilchrist’s initial promising results, as well as Bricker’s description of the simple technique of the ileal loop noncontinent diversion, led to the ileocecal segment as a form of continent urinary diversion to be largely abandoned.
There were several variations of the ileocecal reservoir, such as the Mainz pouch, Penn pouch, and Florida pouch; however, detailed description of each of these is beyond the scope of this chapter. Because of the simplicity and excellent functional outcomes, the Indiana pouch has emerged as the most common ileocecal urinary diversion performed in the contemporary era. In 1984, the Indiana University group began using a continent reservoir based on modifications of Gilchrist’s procedure. First, to improve continence and allow for easier catheterization, the ileal segment efferent limb was tapered via stapling, and the ileocecal valve was plicated using 2-0 silk interrupted sutures. Second, owing to the poor continence secondary to high-pressure contractions off the cecum, a modification involved detubularizing the cecal segment. Our initial attempts at detubularization used a detubularized ileal patch placed on the completely detubularized 15-cm cecal segment. To reduce operative time, we then abandoned the ileal patch technique for a simpler technique of opening a 20-cm segment of the right colon and cecum longitudinally and folding it over and closing it transversely in a Heineke-Mikulicz fashion. This has remained the basis of the reconstructive nature of the Indiana pouch continent urinary reservoir, which has been able to be easily reproduced in its much-simplified form.
The use of continent cutaneous urinary diversion has decreased, as bladder replacement has become a more viable procedure in the form of a neobladder over the past 25 years. Despite this, the urologic reconstructive surgeon must maintain the ability to perform continent cutaneous diversion in patients who are unwilling to accept the potential for nocturnal incontinence observed in all forms of bladder replacement, as well as patients who have ineffective sphincter mechanism, need a urethrectomy, or have had adjuvant pelvic radiation because of their primary disease.
Preoperative Planning and Indications and Contraindications to the Indiana Pouch
Patients with renal function compromise with creatinine greater than 2.0 mg/dL or estimated glomerular filtration rate less than 60 mL/min are not ideal candidates for a continent catheterizable urinary diversion. The excellent continence mechanism and approximately 500-mL urinary capacity may predispose such patients for further compromise in renal function. Lack of diligent scheduled catheterizations may allow for increased urinary dwell time and waste metabolite reabsorption with transmission of pressure to the upper tracts and potential injury to already compromised renal units. Such patients are also more susceptible to hypokalemic hyperchloremic metabolic acidosis. Other contraindications are related to life expectancy and primary diseases of the colon, such as inflammatory bowel disease. Prior radiation to the abdomen and pelvis may preclude use of terminal ileum and colon depending on radiation changes encountered intraoperatively.
Body habitus issues or functional limitations, such as paraplegia, may limit the ability to perform a bladder replacement. However, these patients remain candidates for an Indiana pouch given they can demonstrate normal manual dexterity to perform the necessary catheterizations required with an Indiana pouch. The Indiana pouch is a manageable and preferred diversion in such patients as long as the ability to catheterize and irrigate is documented preoperatively.
Although preoperative bowel preparation for small bowel only urinary diversion is not necessary, bowel preparation for an Indiana pouch is routinely performed because of the use of the large colon. Preparation is achieved in a variety of ways according to the surgeon’s preference. We generally use a low-residue clear liquid diet for 24 hours before surgery along with magnesium citrate. A broad-spectrum antibiotic is administered 1 hour before incision. Use of alvimopan, a µ-opioid receptor antagonist, has shown improvement in pain control and shortened length of hospital stay. This is also continued postoperatively.
Surgical Technique for the Indiana Pouch
After a midline incision has been made and carried down into the peritoneal cavity, a self-retaining retractor is used to assist with retraction. If this is being performed at the time of radical cystectomy for urothelial carcinoma of the bladder, the lower midline incision usually requires extension 4 to 6 cm above the umbilicus to assist with proper mobilization of the right colon.
Blood Supply
The blood supply of the Indiana pouch is based off the superior mesenteric artery (SMA) and its branches. Specifically, the right colon uses the right colic and ileocolic arteries with the terminal ileum utilizing the arterial arcade branches of the SMA.
Mobilization of Right Colon
The right colon is mobilized from the cecum to the hepatic flexure ( Fig. 55.1 ). A total of 20 cm of right colon and 10 cm of the terminal ileum are utilized to construct the pouch. The blood supply of the pouch is based off the ileocolic and right colic arteries, which originate from the superior mesenteric artery. After mobilization, mesenteric windows are created near the hepatic flexure and approximately 10 cm distal to the terminal ileum. Both the large and small bowel are then divided using gastrointestinal anastomosis (GIA) stapling devices. Alternatively, a TA stapling device with a Carmalt bowel clamp on the reservoir side can be used to avoid removing a staple line. The segment to be used for the Indiana pouch is positioned inferiorly, and bowel continuity is restored by creating a functional side-to-side ileocolonic anastomosis with a combination of GIA and TA staplers. Alternatively, a sutured hand-sewn ileocolonic anastomosis may be performed depending on surgeon preference. The mesenteric window is not routinely closed with an Indiana pouch.
Appendectomy
If an appendix is present, an appendectomy is performed. There are several methods through which this can be performed. The appendiceal artery is divided. A purse-string 2-0 Vicryl or chromic suture is placed around the base of the appendix at the cecum. The LigaSure or Enseal device or sharp excision can be used the remove the appendix near the base. The stump of the appendix is inverted into the cecum through the purse-string suture and then tied. An absorbable suture is used because this area may be in contact with urine in the pouch, which will avoid stone formation at the appendiceal stump.
Opening the Right Colon
After the appendix is removed as previously described, the right colon is opened longitudinally using electrocautery between the tinea toward to the cecum, sparing the cecal cap ( Fig. 55.2 ). It is then folded in a transverse fashion and closed with a running-locking 3-0 Vicryl suture utilizing a Heineke-Mikulicz technique ( Fig. 55.3 ). Care is taken to invert the mucosal edges along this suture line. After the pouch is closed, a 24-Fr Malecot catheter is placed in the cecal cap. A 2-0 chromic purse-string suture is placed in the cecal cap in the desired location for the Malecot catheter. When the catheter is placed in the middle of the purse string, the 2-0 chromic purse string is secured around the Malecot. The pouch is then irrigated to check for leaks along the suture line. Any leaks are reinforced with interrupted figure of eight 3-0 Vicryl sutures. The large-bore Malecot catheter provides a good irrigation catheter in the initial postoperative period to prevent mucous plugging of the catheters.
