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Urinary Diversion in Gynecologic Oncology
Pelvic exenteration, the most radical of pelvic procedures, is used with curative or palliative intent in the treatment of women with primary and recurrent pelvic malignancies. In women undergoing total or anterior exenterative procedures, the choice of urinary diversion can have a great impact on functional outcome, intraoperative and postoperative complications, and overall quality of life. The importance of the reconstruction phase on the psychosocial well-being of women cannot be overemphasized because it can avoid the dependence of a permanent colostomy. Over the course of 60 years, various techniques have been described for the construction of urinary diversion since ureterosigmoidostomy was first completed in the early 1900s. The unacceptable rate of retrograde fecal contamination resulting in ascending infections with recurrent pyelonephritis and subsequent loss of renal function paved the way for alternative forms of urinary reconstruction. This chapter describes the various techniques for incontinent and continent urinary diversions that have evolved throughout the years and the management of common postoperative complications.
Historical Perspective of Urinary Diversions
One of the first reported cases of urinary diversion was by Dr. Franklin H. Martin in 1899, who described a ureterosigmoidostomy or wet colostomy. The wet colostomy was the procedure of choice for urinary diversion during the early series of pelvic exenterations as described by Dr. Alexander Brunschwig in 1948. This procedure remained popular from 1900 through the 1950s because it was technically easy to perform and obviated the need to excise an additional and separate section of intestine such as the ileum. Bricker was the first to describe the use of an ileal conduit as an incontinent urinary reservoir as an alternative to the ureterosigmoidostomy, which had proven over time to increase the incidence of electrolyte abnormalities, hyperchloremic metabolic acidosis, urinary and fecal incontinence, recurrent upper urinary tract infections (UTIs), chronic renal insufficiency and failure, hydronephrosis, and ureteral stricturing ( Fig. 21.1 ). He reported a simple and reliable method of urinary diversion with acceptable complication rates, and as a result the ileal conduit became the most common method of diversion in gynecologic oncology. The sigmoid conduit was not reported until 20 years later by Symmonds and Gibbs; this procedure was technically easier and eliminated the necessity to perform an additional small bowel resection and anastomosis. When compared with the ileal conduit, the sigmoid conduit was found to have similar functionality, decreased operative time, and improved postoperative morbidity. Challenges arose in gynecologic oncology practice when sigmoid colon was used for conduit formation, however, because this tissue was often damaged from prior pelvic irradiation. In an attempt to further decrease the rate of conduit leaks, fistulas, and ureteral strictures, the use of the transverse colon for the formation of colonic conduits became popular.
A continent urinary diversion was first described by Gilchrist and colleagues in 1950; this procedure used a segment of cecum, with the ileocecal valve providing the continence mechanism. Subsequent reports highlighted the increase in technical difficulty, higher complication rates, and urinary incontinence resulting from cecal peristaltic hyperactivity. In 1978, Kock and colleagues introduced a continent urinary diversion in which an ileal segment of intestine with an intussuscepted nipple valve was used as the mechanism of continence, with use of a detubularized technique that provided a lower pressure system rather than a straightforward tubular component and a larger volume. The principle of interrupting the circular muscle fibers longitudinally and then folding the intestinal tubular structure to unite the proximal and distal ends, thereby decreasing the pressure gradient produced by the circular muscle contractions, has become the foundation of a low-pressure continent urinary diversion. With a failure rate of 15% to 20% with the Kock ileal pouch, new methods of urinary diversions were explored. In 1986 Thuroff and colleagues published a report describing the creation of a continent urinary diversion, or Mainz pouch, using two loops of ileum, cecum, and ascending colon. The ureters were anastomosed in a nonrefluxing submucosal tunneling technique with an isoperistaltic intussusception distal ileum as the continence mechanism. In 1987, the Indiana pouch was introduced by Rowland and associates; this procedure involved the formation of a right colonic reservoir by plicating the terminal ileum to reinforce the ileocecal valve. With this mechanism, an astounding daytime continence rate of 93% was achieved. Lockhart and Bejany remodeled the Indiana pouch by using the terminal ileum, cecum, and ascending and proximal transverse colon to construct the reservoir, which was folded onto itself; the ileum was plicated with two rows of permanent sutures to form the continent mechanism, allowing for a larger urinary reservoir. The authors reported that a directed nontunneled ureterointestinal implantation was another option to the intussuscepted nipple valve of the Kock pouch to achieve an antireflux ureteral mechanism. In 1989 Penalver and colleagues introduced the Miami pouch into gynecologic oncology; this procedure incorporated modifications such as the placement of the three circumferential permanent sutures in a purse-string fashion proximal to the ileocecal valve and tapering of the ileal segment over a 14F catheter. This surgical technique has become the most popular form of continent urinary diversion in gynecologic oncology. Table 21.1 reviews the different forms of urinary diversions.
Table 21.1
Types of Urinary Diversions
| Ureteral Anastomosis | Cutaneous Anastomosis | |
|---|---|---|
| Incontinent Diversions | ||
| Ureterostomy | Directly to skin | |
| Ureterosigmoidostomy or ureterocolostomy | Anastomosed to the proximal colon | Distal colon exits the skin |
| Ileal conduit | Anastomosed to the proximal ileum | Distal ileum is anastomosed to the skin |
| Sigmoid conduit | Anastomosed to the proximal sigmoid colon | Distal sigmoid is anastomosed to the skin |
| Transverse conduit | Anastomosed to the proximal transverse colon | Distal transverse is anastomosed to the skin |
| Continent Diversions | ||
| Kock pouch | Anastomosed to the proximal afferent nipple made from ileum | Distal efferent nipple of one ileum is anastomosed to the skin |
| Miami pouch | Anastomosed (nontunneled) to a proximal segment of tubularized ascending and transverse colon that is folded onto itself | Terminal tapered ileum with three circumferential sutures abutting the ileocecal valve |
| Indiana pouch | Anastomosed to the proximal end of the ascending colon (transverse colon not used) in a nonrefluxing seromuscular flap | Terminal nontapered ileum with an ileocecal valve bolstered by Lembert sutures |
| Florida pouch | Similar to the Miami pouch | Terminal tapered ileum with two circumferential sutures abutting the ileocecal valve |
| Rome pouch | Anastomosed to the ascending and transverse colon but not tubularized | Terminal tapered ileum with two circumferential sutures or appendix |
| Orthotopic bladder | Anastomosed to a detubularized ileum suture to remaining detrusor and serosa | Native urethra intact |
Indications for Urinary Diversion
Reconstruction of the lower urinary tract has been a challenge for many years. The bladder is a hollow, muscular organ that serves as a low-pressure urine storage reservoir capable of complete emptying via the urethra. Between voids, appropriate bladder capacity maintains continence. When the bladder is crippled by disease and cystectomy is performed, a urinary diversion is needed. The ideal urinary reservoir is one that achieves a low-pressure system that stores a functional amount of urine (about 500 mL), has no absorption of urinary waste products, and is able to maintain complete continence and complete voluntary control of voiding. Metabolic derangements that are encountered from urinary diversion depend on which segment of intestine is used and the specific absorptive function of that specific bowel segment. Consequently, an ideal neobladder has not been found, so any segment of bowel can be used to create a urinary diversion that is functional but may be impaired based on the location, length, intestinal disease, and previous radiation to the specific bowel segment used.
The choice of creating a continent versus an incontinent urinary diversion in the gynecologic oncology patient requires evaluation of a number of different and important factors. First, the surgeon needs to choose a method of which he or she has knowledge—not only of the surgical technique but also of the various complications and their subsequent management. Next, a meticulous evaluation of the size, extent, and previous treatment of the tumor will help exclude specific options. A patient with either primary or recurrent tumor involving the base of the bladder or urethra will not be a candidate for an orthotopic reservoir (use of the patient’s own urethra with a segment of intestine to either augment or replace the bladder). This method of continent urinary diversion restores a more physiologic voiding pattern by allowing the patient to void through the urethra instead of a stoma but requires the patient to provide an adequate Valsalva or suprapubic pressure. The orthotopic neobladder is not frequently described in gynecologic oncology because of the tumor pathophysiology and the frequent involvement of the lower urinary tract in gynecologic cancers. Patients who are elderly or have multiple comorbidities or previous radiation damage should undergo a diversion that has a short operative time and requires less intestinal anastomosis, such as the descending or proximal sigmoid conduit that is outside of the radiation field. If extensive radiation damage is evident, the surgeon should evaluate the previous radiation doses and fields before finalizing any type of urinary diversion.
The patient’s desire, self-image, and ability to manage the care of a continent urinary diversion are central to the decision regarding urinary reconstruction. Patients who are young and have few physical limitations can experience the advantages of continent cutaneous diversions—that is, the elimination of external appliances and the ability to maintain socially acceptable methods of continence ( Fig. 21.2 ). Patients who undergo continent cutaneous diversions must be self-motivated and committed to lifelong intermittent self-catheterization. Patients will also need adequate manual dexterity to perform clean intermittent catheterization through the stoma; therefore, elderly patients who lack the desire or manual dexterity to self-catheterize the neobladder will be better served with an incontinent urinary diversion.
Severe medical comorbidities can result in absolute contraindications for both continent and incontinent cutaneous diversions or orthotopic neobladder. Renal function is important because the patient must be able to tolerate postoperative complications such as ureteral stricture or obstruction or recurrent UTIs and pyelonephritis. Patients with bilateral hydronephrosis should have decompression and improvement of renal function before surgery with either ureteral stenting or percutaneous nephrostomy tubes. If impairment of renal function (defined by a creatinine clearance <50 mL/min or serum creatinine >2.0 mg/dL) persists, than one should consider performing just a cutaneous ureteral diversion. Because most urinary diversions involve the reabsorption and recirculation of urinary constituents and metabolites by the specific bowel segment used, normal liver function is optimal to maintain adequate metabolism and elimination of such byproducts.
Preoperative Management
Preoperative evaluation of every patient undergoing pelvic exenteration and urinary diversion is paramount in decreasing unrealistic expectations, anxiety from changes in body image, unforeseen surprises, and postoperative infectious morbidity and mortality. The morbidity and mortality associated with pelvic exenterations and urinary diversions have decreased over the past few decades as a result of advancements in preoperative care, surgical technique, postoperative care, and interventional radiology techniques. Advancements in surgical technique and surgical critical care have translated into an improved postoperative mortality, which was once reported to be as high as 25% by Brunschwig in 1948. Subsequent articles on pelvic exenterations for gynecologic malignancies have documented improvements in the overall mortality rate to 10% to 12%. The postoperative mortality in the most recent series is about 5%, with a decreasing trend in the past decade, and with causes more often not directly related to the urinary diversion, such as thromboembolic disease, myocardial infarctions, and sepsis.
The great majority of patients who are to undergo pelvic exenteration with urinary diversion and reconstruction are admitted the day of operation, a practice that has changed over the years. Previously, all patients were admitted up to 10 to 14 days before the procedure for total parenteral nutrition, bowel preparation, and consultation with a stoma nurse for ‘’marking’’ for the colostomy and/or urostomy. It is now recommended that a preoperative evaluation be completed in the outpatient setting before the operation to help the surgeon and patient optimize the surgical outcome. This preoperative evaluation includes a thorough preoperative tumor restaging, preoperative clearance, review of previous radiation therapy, evaluation of the medical and nutritional status of the patient, psychological counseling, stoma nurse consultation, preoperative gastrointestinal preparation, and antibiotics.
Tumor Restaging
Magnetic resonance imaging (MRI) and positron emission tomography–computed tomography (PET-CT) are ideal in evaluating the extent and location of the primary or recurrent tumor or urinary defect. This testing enables the surgeon to counsel the patient on the curative or palliative intent of the operation and assists in determining which portion of the gastrointestinal tract is going to be used in the creation of the neobladder. For example, a patient with tumor invasion involving the apical vagina or bladder that is not affecting the bladder neck or levator ani may be a candidate for orthotopic bladder creation. The radiographic findings of possible metastatic disease, which must be confirmed by histopathologic evaluation, would be an essential element in the preoperative counseling of the oncologic patient with regard to her understanding of aborting such a radical procedure if it will not be curative.
Medical Optimization
Pelvic exenteration with concomitant urinary diversions and vaginal and pelvic floor reconstructions are radical and extensive surgical procedures, with long operative times, fluid shifts, and blood loss, that would create a significant physiologic strain on any healthy patient, let alone a woman with unstable comorbidities. For this reason, a detailed medical evaluation with emphasis on the cardiovascular and pulmonary systems is important in order to optimize operative and postoperative care. In addition, routine laboratory testing of hematologic, metabolic, hepatic, and renal function is also required to help predict and manage the metabolic derangements that may result from urinary diversion, such as hypokalemia or hypochloremic metabolic acidosis. Poor nutritional state preoperatively can predict poor wound healing, infection, and delayed recovery postoperatively and should be managed by providing preoperative nutritional supplementation and even postoperative total parenteral nutrition.
Gastrointestinal Evaluation
A preoperative colonoscopy should be considered to help exclude metastatic disease and other pathologic changes such as diverticula, ulcers, large polyps, or strictures that could affect the reconstruction of any given segment of intestine.
Previous Radiotherapy Dosages
A review of a patient’s previous radiation therapy, isodose curves, and total dose administered to the pelvis may be of benefit in avoiding use of heavily pretreated intestinal segments as the donor site for the urinary reservoir. Use of areas of intestine that received an additional boost of radiation above 65 Gy with fraction size above 2 Gy results in a higher incidence of toxicity in the treatment of primary or recurrent cancer and should be avoided. Knowledge of such radiation doses to the pelvis by the surgeon will assist in the preoperative surgical planning with regard to which segment of intestine to use in the reconstruction (e.g., descending colon rather than distal sigmoid).
Psychological Consultation
The diagnosis of recurrent or advanced pelvic malignancy is traumatic, and this trauma is compounded by the radical and often disfiguring extirpation of all or part of the pelvic organs. This results in alteration in body image, changes in sexual intimacy, and a dramatic shift in the patient’s urinary and bowel habits. Psychosocial counseling can help a patient understand, face, and begin to accept the changes that she will be undergoing in the postoperative period. The process of accepting and embracing these bodily changes is paramount in the transition to caring for the new external appliances in the immediate and long-term postoperative care.
Ostomy Nurse or Wound Care Consultation
It is important to determine the positioning of a urinary and fecal diversion stoma preoperatively. The placement of the stoma is dependent on the segment of intestine that is to be used. A transverse conduit stoma can be created in the upper quadrant more easily than in the lower quadrant. As a general rule, one should attempt to position the continent diversion stoma in either the right lower quadrant or the umbilicus. The umbilicus provides a more pleasing cosmetic result but does require some preoperative planning, so that the surgeon knows to leave an adequate amount of fascia lateral to the umbilical base to allow for a safe fascial closure, as well as to evaluate the periumbilical caliber for hernias that would also complicate its use. A nurse will educate the patient regarding the types of appliances, method and frequency of application, and possible complications. For continent reservoirs, the patient will be educated regarding the proper care and maintenance of the drainage catheter, frequency of catheterization, and frequency of saline flushes of the neobladder. The last is important because this practice prevents overdistention and perforation of the neobladder by removing the mucus that may obstruct the outflow.
Mechanical Bowel Preparation
Mechanical bowel preparation is no longer used universally in elective colon resection because a number of randomized trials have shown that there is no benefit in postoperative reduction of surgical site wound infection. However, a number of large retrospective studies compared mechanical bowel preparation with oral antibiotic therapy and found that it can reduce surgical site infection and overall complication rates, except for Clostridium difficile infection, which may be increased. The largest study was performed by the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) targeted colectomy data who reviewed 8442 patients and reported that surgical site wound infection decreased from 12% to 6%, postoperative ileus from 12.3% to 9.2%, and anastomotic leak from 3.5% to 2.1%. In addition, a 2015 meta-analysis of seven randomized trials also showed a reduction in overall surgical site wound infection by half, with no effect on deep infections in patients who received oral antibiotics plus mechanical bowel preparation compared with just mechanical preparation. Specific to urinary diversion, a meta-analysis of two randomized trials failed to show an improvement in rates of obstruction, anastomotic leak, or mortality with mechanical bowel preparation.
Based on the best available data, it is the chapter authors’ practice to administer both mechanical bowel and oral antibiotic preparation in patients undergoing exenteration and urinary diversion. The preferred method of bowel preparation includes neomycin sulfate 1000 mg and erythromycin 1000 mg orally at 1:00 pm , 2:00 pm , and 10:00 pm the day before operation and 8:00 am the day of operation, and start polyethylene glycol 8 oz every 10 minutes until 4 L are ingested starting at 6:00 pm the day before surgery.
Venous Thromboembolism Prophylaxis
Patients with recurrent or advanced cervical cancer who are candidates for exenteration and urinary diversion have the highest risk factors for venous thromboembolic disease, especially when evaluated with the available predictive models such as the Caprini score. Two retrospective studies reported incidence rates of venous thromboembolism (VTE) of 6% to 9% among patients with gynecologic malignancy who underwent exenteration and urinary diversion. The patients in both these studies received heparin subcutaneously, although the timing of administration and the duration are not well documented. The chapter authors’ recommendation is that all patients receive venous thromboembolic prophylaxis immediately after operation, including pneumatic compression devices and unfractionated or low-molecular-weight heparin during the early postoperative period once the hemoglobin level is found to be stable, and for 30 days. In certain patients who appear to be at high risk clinically of having a deep venous thrombosis, a preoperative venous Doppler ultrasound examination should be ordered, and if the findings are indicative of a deep venous thrombosis, an intravenous vena caval filter should be placed.
Preoperative Antibiotics
Because the risk of surgical site wound infection is approximately 5% to 12% for a clean-contaminated wound, and probably higher among high-risk women with previous irradiation and poor nutritional status, preoperative use of antibiotics is prudent. For patients undergoing urinary diversion, the choice for prophylactic antibiotic therapy is best extrapolated from the studies in the colorectal literature. Accordingly, intravenous antimicrobial prophylaxis with a second-generation cephalosporin such as cefoxitin or cefotetan or cefazolin plus metronidazole is warranted. In β-lactam–allergic patients, the intravenous antibiotics indicated include clindamycin plus gentamicin or ciprofloxacin or aztreonam. The antibiotic prophylaxis should be redosed if the surgical time exceeds two half-lives of the drug or if blood loss is greater than 1500 mL.
Blood Products
The average blood loss during an exenterative procedure is about 1000 to 1500 mL, and so preoperative preparation to avoid cardiovascular decompensation is wise. All patients undergoing exenteration with urinary reconstruction should be typed and cross-matched for at least 4 to 6 units of packed red blood cells. Equally important is venous access for urgent fluid or blood product resuscitation with a large-bore intravenous catheter such as a 16- to 18-gauge catheter and also a central venous catheter such as a central or peripherally inserted central catheter (PICC) line, placed before the start of the operation.
Surgical Techniques for Urinary Diversion
The choice of urinary diversion is complicated and multifactorial. Currently, the surgeon has many more options at his or her disposal compared with the initial description of ureterosigmoidostomy or wet colostomy by Brunschwig (see Table 21.1 ). Furthermore, the notion that incontinent conduits are the safer alternative for reconstruction of the urinary bladder in patients with recurrent or advanced gynecologic cancers has been evaluated by a number of authors. These studies have compared various forms of incontinent and continent urinary diversions and have found them to be equivalent in terms of postoperative morbidity and mortality. The next section describes the various urinary diversion techniques, with special emphasis on the Miami pouch or ileocolonic continent urinary reservoir.
Incontinent Urinary Conduits
After the 1940s, the ileal conduit, first described by Bricker, became the preferred method of urinary reconstruction in order to decrease the complications of a wet colostomy such as recurrent UTIs and pyelonephritis and thus loss of the renal unit. The three techniques currently used in the formation of incontinent diversion are the ileal, transverse, and sigmoid colon conduits. In general, these procedures are faster and easier to perform than continent urinary diversions, ideal for patients who have difficulty self-catheterizing or no desire to do so. There remains debate in the gynecologic literature as to which form of conduit is ideal and has the fewest postoperative complications. Most of the largest case series that have either described or compared these various forms of conduit creation have failed to find any significant advantage with a specific host site. Tabbaa and colleagues (2014) from the Mayo Clinic evaluated short-term outcome of ileal, transverse, and sigmoid conduit procedures in 129 patients. They reported no statistically significant difference in rates of conduit-related complications overall but did find that sigmoid conduits tended to have an increased rate of intervention and repair. The overall significant conduit-related complication rate within 30 days was 15% (ileal, 14.7%; transverse, 0%; sigmoid, 20%) and within 90 days was 22% (ileal, 22%; transverse, 0%; sigmoid, 29%). The most common complications included conduits leaks (ileal, 11%; transverse, 0%; sigmoid, 20%), ureteral anastomotic leak (ileal, 4%; transverse, 0%; sigmoid, 0%), and ureteral stricture (ileal, 3%; transverse, 0%; sigmoid, 0%). Similar results were reported in 1986 by the group at MD Anderson; these researchers compared all three types of conduits and found that the sigmoid conduit was associated with the highest incidence of complications and the ileal conduit with the lowest.
The higher rates of short- and long-term complications with both ileal and sigmoid conduit creation have prompted many gynecologic oncologists to recommend the use of the transverse colon, which would avoid use of the segments of intestine within the irradiated field. In addition, the transverse colon anatomically allows for ease of mobilization because of lack of adhesions, facilitates stomal placement, and allows for higher ureteral anastomosis, especially with shortened ureteral lengths. The three most common techniques for incontinent urinary diversion including ileal, transverse, and sigmoid conduits are described in the following sections.
Ileal Conduit Surgical Technique (see Fig. 21.1 )
Surgical Steps
Step 1
A 20- to 25-cm segment of terminal ileum is evaluated for any radiation effects or adhesive disease. This segment should be about 15 cm from the ileocecal valve to allow for ample room for the reanastomosis. If the ileum is found to be compromised, then a segment of jejunum can be used to limit postoperative complications. The length of ileum used is dependent on the length needed from the ureters to the skin.
Step 2
The ureterolysis is performed next to allow a determination of the length of the conduit, but sparingly to allow just enough length for a tension-free anastomosis. The left ureter can be tunneled through the sigmoid or the descending colon mesentery. The ends of the ureters are trimmed to produce healthy ends and then spatulated about 0.5 to 1 cm with Potts scissors, which avoids stricturing of the ureteral anastomosis.
Step 3
The gastrointestinal anastomosis (GIA) 55-mm stapler is used to transect the proximal and distal end through an avascular mesenteric window adjacent to the intestinal serosa to avoid compromising the mesentery. The small bowel can then be reanastomosed in a side-to-side fashion by using a standard approach. Mobilization of the intestinal mesentery is minimized to allow a tension-free approximation to the skin for the stoma.
Step 4
At the proximal end of the ileal conduit (side opposite to the ostomy end), Metzenbaum scissors are used to create a 5-mm opening on both sides of the ileal wall on the antimesenteric end. The distal end is opened at the staple line to irrigate with betadine and saline until clear to remove all remaining fecal material within the ileal conduit.
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