(1)
Department of Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
Abstract
This chapter discusses the diagnostic and management approach to the rare but important rectourethral fistula. The most common cause of this fistula is iatrogenic at the time of prostatic surgery, although it may also result from prostate brachytherapy. The operative approaches are individualized and may include abdominal, per-anal/endoanal, perineal, transsphincteric (York-Mason), posterior (Kraske style), and pararectal procedures. The outcomes of these approaches and the use of biologic glues for this specific condition are discussed.
Keywords
Rectourethral fistula (RUF)CloacaAnorectal malformationsProstate surgeryExternal beam radiation therapy (EBRT)BrachytherapyRadiofrequency ablationCryotherapyCrohn’s diseasePeriurethral abscessRecurrent perineal abscessProstate cancerRectal cancerTraumaUrinary tract infectionPneumaturiaFecaluriaIntroduction
Given the anatomy of the female pelvis, rectourethral fistulae (RUF) occur only in men. Multiple conditions can result in an RUF, but the most common cause is an iatrogenic fistula usually associated with surgery or therapy for benign prostatic disease or prostate cancer. RUF in prostate cancer has been recognized after brachytherapy, often appearing within 2 years after therapy [1].
The etiologies responsible for RUF include the following:
Congenital – cloaca, low and high anorectal malformations
Iatrogenic – prostate surgery or therapy for prostate conditions utilizing external beam radiation therapy (EBRT), brachytherapy, radiofrequency ablation, and cryotherapy
Inflammatory – Crohn’s disease, periurethral and recurrent perineal abscess
Neoplastic – prostate or rectal cancer
Trauma
Anatomy
The Prostate and the Rectum
The prostate gland is ovoid in shape, with an apex inferiorly and base superiorly, and weighs approximately 18 g. The apex of the gland is located on the urogenital diaphragm. Despite its shape, it is described with anterior, posterior, and lateral borders. The prostate gland is suspended by the puboprostatic ligaments inserting into the anterolateral aspect of its capsule. It is encapsulated in a fibromuscular sheath, which is about 0.5 mm thick posteriorly. The prostatic capsule is adherent to Denonvilliers’ fascia posteriorly and laterally it merges with the endopelvic fascia lying over the levator ani muscle. It is separated from the anterior wall of the rectum by a thin layer of areolar tissue and Denonvilliers’ fascia, which is adherent to the prostate capsule posteriorly.
The urethra within the prostate angles anteriorly about 35°. This angle can vary between 0 and 90°. The urethra is divided into the proximal (preprostatic) and distal (prostatic) urethra. The circular smooth muscle in the preprostatic urethra is condensed and constitutes the involuntary urinary sphincter. The urethra distal to the apex of the prostate is the membranous urethra, which is about 2–2.5 cm in length (range, 0.5–5 cm). It is surrounded by striated muscle constituting the voluntary external urinary sphincter. This sphincter extends the length of the membranous urethra and inserts distally into the perineal body.
The rectum starts at the pelvic inlet as the taenia coli of the colon coalesce into a complete circumferential muscle layer around the large intestine. The rectum is partially intraperitoneal. It then courses behind the seminal vesicles and the prostate around the mid-rectum. The peritoneum lines this cul-de-sac over the seminal vesicles anteriorly and the mid-rectum posteriorly. Denovilliers’ fascia [2] then separates the upper prostate from the rectum (and is thought here to be formed by two layers of peritoneum entrapped between the two organs). Below Denonvilliers’ fascia the lower prostate and the rectum are separated by the prostatic capsule and some mesorectal fat. Below the prostate the membranous urethra comes into close proximity with the lower rectum and the upper anus before it turns anteriorly toward the penile body.
The Anal Triangle
At the apex of the prostate, the rectum turns posteriorly and inferiorly and becomes the anal canal. The anal canal is approximately 4 cm in length and reaches the perineum in the center of the anal triangle. The canal is surrounded by the involuntary internal anal sphincter and the voluntary external anal sphincter. The external anal sphincter has three components: the subcutaneous, superficial, and deep aspects [3].
The Male Urogential Triangle
The urogenital diaphragm lies inferior to the levator ani. It occupies the anterior aspect of the male and female perinea. In men, deep to the skin and subcutaneous fat, the ischiocavernosus muscle surrounds the corpora cavernosi and attaches to the ischiopubic rami and the perineal membrane laterally. The bulbospongiosus encompasses the corpus spongiosus and forms the midline raphe and is fused to the perineal body posteriorly. The superficial and deep transverse perineal muscles constitute the posterior border of the urogenital diaphragm and also are fused to the perineal body [4].
Presentation of RUF
Patients with RUF present with one of the following complaints: passing urine through the rectum, recurrent urinary tract infections, pneumaturia, and fecaluria. There is usually an associated history of prostate surgery, prostatic radiation therapy, or a prior rectal procedure. In addition, some patients may present with metabolic acidosis from excessive reabsorption of urinary acids through the rectum [5]. Also, infertility has been reported as a presenting symptom [6].
In patients who have undergone radiation therapy for prostate cancer (either with seeds or with external beam therapy), persistent perineal or rectal pain may precede presentation of a fistula. In addition, these patients may develop an anterior rectal ulcer and bleeding per rectum years after therapy for prostate cancer, preceding the development or presentation of a fistula. The time to development of an RUF after iatrogenic injury is variable and can be divided into two main categories: early or delayed. Early presentation is defined as within 30 days of surgery. Most patients with an iatrogenic injury during prostate surgery are recognized and the injury is repaired primarily. Failure to heal this iatrogenic repair can lead to development of an RUF approximately 7–10 days after surgery. Unrecognized injuries to the rectum during prostatectomy present early, with complaints of passage of urine through the rectum about 1–3 days after surgery or after removal of the Foley urinary catheter. Patients undergoing brachytherapy or EBRT for prostate cancer present in a delayed fashion. The time to presentation can range from 9 months up to 5 years.
History
Wagernus was the first to describe an RUF in 1685. Sir Astley Cooper made the first surgical attempt to treat an RUF in 1823 by simple perineal drainage. In 1831, Bushe attempted surgical division of an RUF. A detailed description of early attempts and principles used to repair RUF are reported by Weyrauch [7].
Incidence
The incidence of RUF after prostate surgery has been reported in multiple studies. Eastham and Scardino [8] reported an incidence ranging from 0.2 to 2.9 % (average, 0.7 %) among 3,834 patients undergoing radical retropubic prostatectomy (RRP). Thomas et al. [9] reported a 0.53 % rate of RUF in 2,447 patients undergoing radical prostatectomy. Not all unrecognized rectal injuries or rectal repairs after prostate surgery result in RUFs. Smith and Veenema [10] reported 15 rectal injuries in 160 patients undergoing RRP over 20 years, and of these 15 patients, 4 developed RUF. In another study, 23 of 589 patients undergoing RRP and cystoprostatectomy had a rectal injury. Of these 23 injuries, 12 developed RUF [11]. Castillo et al. [12] reported 9 rectal injuries among 110 patients undergoing retroperitoneal laparoscopic prostatectomy. Seven of these injuries were recognized immediately and primarily repaired during surgery. One of the repairs broke down, so the result included a total of three RUFs overall (one repaired injury and two unrecognized rectal injuries).
Ablative techniques including prostatic cryotherapy, radiofrequency ablation, brachytherapy, and prostate hyperthermia can all result in inadvertent injuries to the rectum, which usually are delayed. The incidence of RUF after prostate cryosurgery, prostate biopsy, and brachytherapy for stage T1/T2 prostate cancers has been reported between 2–5, 2.5, and 3.2 %, respectively [13–15]. Theodorescu and colleagues [16] reported an incidence of RUF of 1 % in 754 patients treated with brachytherapy for prostate cancer. The incidence varied between 0.2 % for brachytherapy only and 8.8 % for combined brachytherapy and salvage prostatectomy.
Rectal injury also can occur with newer prostate surgery procedures. An injury occurred in 18 of 11,452 patients undergoing robotic or laparoscopic retropubic prostatectomy over 10 years [17]. Twelve patients were in the robotic surgery group (0.12 % incidence) and six had undergone laparoscopic surgery (0.47 % incidence). Sixteen rectal injuries were recognized and repaired primarily with interposition of omentum to separate the urinary and rectal suture lines. RUF developed in a total of four patients (two with recognized and repaired injuries and two with unrecognized injuries). The incidence of Crohn’s-related RUF is low, with only 13 cases so far being reported, the last of which was in 1995 [18].
Classification
There are two classification systems for RUF. One relates to the position of the fistula, whereas the other refers to patient “function.”
Anatomic Classification
High – rectovesical (rectum to bladder proper or trigone)
Middle – rectoprostatic (rectum to prostatic urethra or membranous urethra)
Low – rectobulbar (rectum to bulbar urethra)
Functional Classification [19] with Suggested Operative Therapies
Stage 1
Low, <4 cm from anal verge, nonirradiated
Transanal repair
Stage II
High, >4 cm from anal verge, nonirradiated
Transrectal/transsphincteric repair and anterior rectal flap
Stage III
Small, <2 cm irradiated fistula
Transrectal/transsphincteric repair and anterior rectal flap
Stage IV
Large, >2 cm irradiated fistula
Perineal repair with gracilis myocutaneous flap
Stage V
Large ischial decubitus fistula
Perineal repair with gracilis myocutaneous flap
Investigations
Most cases of RUF can be detected during physical examination. Rectal examination usually will detect a defect in the anterior wall of rectum and can determine the size, number, and location of fistulous openings. In this respect, physical examination alone diagnoses 94 % of cases of RUF after prostate surgery [20]. Further investigations are, therefore, needed to determine the anatomy of the fistula rather than to confirm the diagnosis.
Flexible sigmoidoscopy is the next best test after the physical examination. The scope will confirm the findings of the rectal examination and rule out other associated pathology such as rectal cancer, recurrent prostate cancer, Crohn’s disease, and radiation proctitis. A biopsy of the edge of the fistulous opening will rule out specific etiologies (including malignancy or Crohn’s disease) that would preclude healing by simple repair. A biopsy should be performed when there is a history of prostate or rectal malignancy to rule out recurrence and when specific etiologies are suspected. However, in a patient who has received brachytherapy, biopsy of an ulcer of the anterior rectum before the onset of an RUF actually can lead to a fistula. In these cases, biopsies should be performed with great care and only if there is a question of malignancy as the cause of the ulcer.
Evaluation of urinary continence is warranted before further investigation because incontinence will not be addressed by repair of the fistula. Cystoscopy is recommended in all patients before attempted repair to determine the size and location(s) of the urethral end of the fistulous opening. The relationship of the urethral injury to the ureteric orifices is also critical to prevent injury to a ureter during the repair. Defining this anatomy is especially important in “high” fistulae. In addition, cystoscopy can rule out a significant urethral stricture that is sometimes associated with an RUF. If present, a urethral stricture will need to be addressed with the repair of the RUF.
Urodynamic studies sometimes are indicated in patients with urinary incontinence or a urethral stricture, particularly after pelvic irradiation because bladder compliance sometimes can be an issue [21]. A voiding cystourethrogram/retrograde urethral cystogram also can be helpful in identifying the course of the fistula. This study may add additional information to previous investigations, especially in patients with a complicated fistulae due to Crohn’s disease. A gastrografin enema may provide additional information about the fistula location. Both urodynamic studies and gastrografin enemas are most useful in evaluating the status of a repair. Magnetic resonance imaging of the perineum has been used to define the course of a fistula, with special attention given to involvement of the anal sphincters and the levator ani muscle; experience in this area has been gained in relation to congenital anorectal malformations [22].
Principles of Repair
Repair of an RUF involves separation of the two epithelialized surfaces: the urothelium and the rectal mucosa. Goodwin et al. [23] in 1958 recommended repair with nonoverlapping suture lines, the introduction of vascularized tissue between the urothelium and the rectal mucosa, and repair preceded by diversion of both the urinary and fecal streams. With the advent of bowel preparation, prolonged antibiotic administration, and long-term indwelling Foley catheters, successful RUF repair without diversion also has been described [7, 23]. Kasraeian and colleagues [24] proposed a single-stage repair without diversion, reporting excellent results. This group diverted the fecal and urinary streams only in patients presenting with peritonitis, uncontrolled sepsis, or frank abscesses. In this respect, Nyam and Pemberton [20] proposed no role for diversion as the sole modality of treatment, using only a colostomy in patients with sepsis or when healing was compromised, such as in the case of large fistulae or in irradiated tissue.
Some fistulae, especially those of small diameter or of long length with no ischemic tissue (without EBRT, brachytherapy, cryotherapy, or hyperthermia), clearly may heal with diversion only [20]. Wilhelm [25] described 9 of 13 fistulas managed with diversion only (all with a colostomy), all of which healed, and, similarly, Goodwin et al. [23] described healing in 9 of 22 cases of RUF with varying lengths of only urinary catheter drainage without surgical intervention or recurrence.
General and local factors impact wound healing and closure of a fistula in all locations. Factors specific to RUF that prevent healing are an inherently short fistula length, overlapping repaired epithelia, significant fibrosis, diminished vascularity after radiation therapy, and, occasionally, concomitant urethral stricture distal to an attempted repair. Clearly, the first repair has the best chance of success, so the main principles described and the most appropriate approach must be undertaken as the first step. Culp and Calhoon [26] in 1964 stressed that surgeons invariably choose the approach that they are most comfortable with, which is as true today as it was then, perhaps echoing the early thoughts of Weyrauch [7], who in 1951 wrote the following:
The operation must be technically simple in order that it may be readily executed by the average urologist. As in all operations, good results are in direct proportion to the simplicity of the procedure. Prompt healing must be assured by one operation and a good functional result as concerns urinary and fecal control is essential.
Today, the incidence of RUF has increased primarily because of an increased use of brachytherapy, EBRT, or the use of other ablative techniques for the treatment of prostate cancer. The incidence of surgical rectal injuries that occur during prostatectomy and result in RUF is relatively stable at less than 2 %. Radiation-induced RUF poses a challenge when repair is contemplated because radiotherapy results in a loss of vascularity, extensive fibrosis, and larger fistulae. With these new types of radiation-induced fistulae, the use of a vascularized flap is essential to facilitate healing and cover larger defects.
Repairing Rectal Injury During Prostatectomy
Rectal injury is relatively rare during prostatectomy or other urological procedures. Rectal injury during cystoscopy may be managed with the placement of a urethral catheter for a few weeks, allowing the urethral and rectal injuries to heal. During prostatectomy, when an injury occurs, the surgeon should debride the rectal wall, especially in cases of cautery injury, and then approximate healthy tissue with primary repair using absorbable sutures. If possible, an omental flap should be created to separate the vesicourethral anastomosis and the repaired rectum. Creation of a colostomy is not essential [27, 28] but is added in some cases as part of a conservative approach. An alternative option includes placing patients on a low-fiber or parenteral diet during immediately after rectal injury repair in conjunction with broad-spectrum antibiotics. The use of a diverting colostomy is based on the quality of the bowel preparation at the time of injury, the extent of the injury, and the presence of immediate or delayed sepsis or frank abscess formation.
Techniques of RUF Repair
Munoz et al. [29] have described 40 different operative approaches for this problem, whereas Nyam and Pemberton [20] from the Mayo Clinic described 8 different methods of repair with 16 cases of RUF. We will limit our discussion to what we believe are the current and best approaches and will not address repair of an RUF in children associated with anorectal malformations.
Surgical Options
Abdominal approach:
Repair of the fistula and a coloanal pull-through procedure
Resection (cystectomy and proctectomy)
Anterior approach:
Perineal approach
Per-anal approach:
The Parks and Motson approach
Transanal endoscopic microsurgery
SILS port approach
Posterior approach:
Transsphincteric (York-Mason) approach
Kraske/transcoccygeal approach
Laterosacral approach
Abdominal Approach
The abdominal approach to the repair of an RUF risks the associated morbidity and mortality of any difficult reoperative intra-abdominal procedure. In addition, it entails a difficult dissection of Denonvilliers’ fascia, which is usually fibrotic as a result of the fistula and because of previous surgery, radiation therapy, or both. Anterior exposure can be limited, preventing repair of the urothelium, although it allows repair of the rectum. An abdominal approach allows for the creation of an omental flap to separate the two epithelial surfaces and is required when a cystectomy or proctectomy is necessary. Typically, these resections are used only after other attempts at repair of an RUF have failed. Results of abdominal repairs are shown in Table 39.1.
Table 39.1
Results of the abdominal approach to repair of RUF
Author (year) [reference] | No. of patients | RT/cryotherapy | Graft | FC | UC | Recurrence | Overall success rate (%) |
|---|---|---|---|---|---|---|---|
Nyam and Pemberton (1999) [20] | 3 | 0/0 | None | NS | NS | 1 | 66 |
Lane et al. (2006) [30] | 9 | 9/0 | Buccal | 5 | 5 | 0 | 100 |
Sotelo et al. (2007) [31] | 3 | 0/0 | None | NS | NS | 0 | 100 |
Perineal Approach
This approach can be used with the patient in either the lithotomy or prone jack-knife positions. The perineum is incised through a midline or transverse incision, approaching the rectal/urethral plane between the urethra and the external anal sphincters. This approach may require division of the transverse perineal muscle. With this approach, a Foley catheter is essential for the identification of the urethra. Sometimes the Foley catheter has to be placed using cystoscopic guidance or retrogradely via the bladder. When the fistula is identified, dissection is continued around the RUF laterally and proximally, if feasible. Alternatively, the RUF can be divided distally, identifying the urothelium and the rectal mucosa and by defining healthy margins laterally and proximally. We try to repair the rectum and the urethra separately and then place a flap or other barrier between the suture lines. The gracilis flap, vascularized tunica albuginea, and a dartos flap all have been described. In addition, the levator ani muscles also have been interposed between repaired suture lines. As an alternative, Young and Stone [32] have reported resection of the involved rectum after mobilization and prolapse through the anus followed by suturing of the proximal rectum to the anus perineally. In addition, they repaired the urothelium and excised the fistula using this approach.
Results of the Perineal Approach
Table 39.2 outlines results of the perineal approach. In 1947, Lewis [41] reported repair of 13 cases of RUF using the perineal approach, with successful results in 11 patients. One patient did not heal, and the results of the other patients are unknown. Nevertheless, their repair involved a perineal approach with identification and division of the RUF. The urethra and rectum were repaired using a chromic catgut suture in two layers. The rectum was mobilized to offset the rectal repair distal to the urethral repair. In addition, the levator ani muscles were mobilized and sutured between the urethral and rectal repairs, as was subsequently described by Goodwin et al. [23].
Table 39.2
Results of the perineal approach to repair of RUF
Author (year) [reference] | No. of patients | RT/cryotherapy | Graft | FC | UC | Recurrences | Overall success rate (%) |
|---|---|---|---|---|---|---|---|
Wilhelm (1945) [25] | 4 | 0/0 | None | Unknown | Unknown | 0 | 100 |
Culp and Calhoon (1964) [26] | 15 | 1/0 | None | 15 | 12 | 6-2P | 60–86.6r |
Nyam and Pemberton (1999) [20] | 3 | 0/0 | NS | NS | NS | 1 | 66 |
Zmora et al. (2003) [33] | 11/5R | 6/0 | Gracilis | 11 | 6a | 2 | 81–100r |
Rabau et al. (2006) [34] | 4/4R | 0/0 | Gracilis | NS | NS | 0 | 100 |
Elliot et al. (2006) [35] | 7 | 1/1 | Dartos(2) | NS | NS | 1 | 85.7 |
Varma et al. (2007) [36] | 8 | 0/0 | Dartos | NS | NS | 2 | 75 |
Gupta et al. (2008) [37] | 15/3R | 0/0 | Gracilis | 14 | 15 | 1 (FE) | 100 |
Ghoniem et al. (2008) [38] | 25 | 17/2 | Gracilis | 19 | 13 + 5b | 2 (FF) | 100 |
Wexner et al. (2008) [39] | 36/13R | 17/4 | Gracilis | 29c | 8-1P | 78–97r | |
Nerli et al. (2009) [40] | 3 | 0/0 | Tunica vag | NS |
