Intestinourinary Fistulas



Intestinourinary Fistulas


RYAN L. MORI

ERIC A. KLEIN

KENNETH W. ANGERMEIER



An intestinourinary fistula is a pathologic extra-anatomic epithelialized connection that can be described based on the respective intestinal and urologic segments involved (i.e., enterovesical, colovesical, rectovesical, rectourethral). This chapter will describe the etiology, evaluation, and management of intestinourinary fistulas with special emphasis on intestinovesical and rectourethral fistulas.


INTESTINOVESICAL FISTULAS


Etiology

The etiology of enterovesical and colovesical fistulas can be divided into three broad categories: inflammatory, neoplastic, and traumatic (Table 25.1). In modern series, diverticular disease is the most common etiology representing 67% of cases, followed by malignancy in 15% and Crohn disease in 9% (1,2). A history of pelvic irradiation increases susceptibility and complexity. Men are affected twice as commonly as women due to the presence of the uterus and broad ligament as a protective barrier. Up to 50% of women with colovesical fistulas have undergone previous hysterectomy (3).



Management

Given the symptomatic nature, the potential for morbidity, and the associated underlying bowel pathology, most intestinovesical fistulas should be addressed surgically. The principles of surgical management include removal of the diseased segment of intestine as well as the fistula tract with or without defunctionalization of the affected bowel segment with a proximal diversion. Typically, the bladder can be managed with 7 to 10 days of catheter drainage with minimal need for resection or repair especially in the setting of benign bowel disease (6). Larger bladder injuries are typically managed with two-layered closures. For this reason, surgery is often directed by the colorectal surgeon with assistance from the urologist when necessary.

A one-stage approach with bowel resection and reanastomosis has become the standard because it is associated with fewer complications and lower mortality, but management must be based on the underlying pathology on a case-by-case basis. Even in the setting of abscess or purulent peritonitis, a one-stage approach can still be safely performed given that the inflammatory focus is resectable and the bowel anastomosis can be “quarantined from any inflammatory nest” (3). A two-stage approach should be considered in patients with bowel obstruction or when there is concern for a healthy anastomosis such as in the setting of extensive locoregional abdominal sepsis, significant inflammation, or in the setting of prior radiation. The two stages may consist of bowel resection with a Hartmann procedure followed by reanastomosis, or resection with anastomosis and proximal diversion followed by delayed restoration of bowel continuity. Some patients, especially those with a history of radiation, may require permanent bowel and/or bladder diversion.

Nonoperative or minimally invasive management may be considered in patients who are deemed unfit for surgery. Spontaneous closure is rare but may occur especially in the setting of traumatic rather than inflammatory fistulas. Evaluation of several series of patients with intestinovesical fistula provides some information on patients who refuse or are unfit for surgery. Although Amin et al. (7) demonstrate that patients with diverticular colovesical fistulas may get by without significant complications in some circumstances, Thomas et al. (1) demonstrate a high rate of mortality without intervention.


Surgical Technique


One-Stage Surgery

On the day prior to surgery, a mechanical bowel preparation is administered and the patient is maintained on a clear liquid diet. Gram-negative and anaerobic coverage is provided by administering a third-generation cephalosporin and metronidazole within 1 hour of surgical incision.

The majority of fistulas can be best approached by a midline laparotomy incision extending from the pubic ramus to the umbilicus (Fig. 25.1), with cranial extension as needed. The peritoneum is entered, adhesiolysis is performed as needed, and the site of the fistula is identified. The remainder of the procedure is determined by the underlying disease causing the fistula and any associated complications. Patients with Crohn disease often have multifocal fistulas not involving the urinary tract and may require multiple resections or stricturoplasties. In malignant fistulas, the requisite oncologic procedure is performed with resection of the fistula tract.

Fistulas associated with malignancy or large cystotomies may require partial cystectomy. Closure of small or unidentified cystotomies is not essential. Larger bladder defects should be closed in two layers with absorbable suture. A large or difficult to access bladder defect may require a midline anterior cystotomy. In the setting of ureteral involvement, ureteroneocystostomy may be required. Whenever possible, healthy tissue such as an omental or peritoneal flap should be interposed between the bowel and the bladder repairs, especially in the setting of radiation or poor tissue quality. Extraperitoneal
drainage should be conducted, especially in the setting of a large bladder repair. A urethral catheter should be maintained for at least 7 days postoperatively, and in the setting of a more involved bladder repair, suprapubic catheter drainage may be used as well. A laparoscopic approach has also been described with good success (8).






FIGURE 25.1 Management of an enterovesical fistula using bowel resection and restitution with primary bladder closure.



RECTOURETHRAL FISTULAS


Background

Over the past decade, there have been some changes in the surgical approach to rectourethral fistulas (RUFs). This has corresponded with a number of new therapies for prostate cancer and the transition of management toward the urologic surgeon. There are several surgical approaches that are acceptable. The management of each case is unique and must consider fistula etiology, complexity, associated urinary or bowel dysfunction, associated urethral or bladder neck stricture, and patient performance status.

The urologic surgeon should be familiar with the transperineal approach because it offers excellent exposure to both the urinary and rectal components of the fistula, allows for multiple potential interposition flaps, and is applicable to the repair of both simple and complex fistulas.

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Apr 24, 2020 | Posted by in UROLOGY | Comments Off on Intestinourinary Fistulas

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