Vesicovaginal and Urethrovaginal Fistulas
Rony A. Adam
DEFINITIONS
Fistula—An abnormal passage or communication that leads from one hollow organ to another.
Interposition graft—Placement of tissue attached to its own blood supply into the space between two viscera to enhance the likelihood of successful repair. Examples include a Martius graft or omental flap.
Retropubic vesicovaginal fistula repair—Access to the fistula and its closure involves dissection in the retropubic space (space of Retzius). This may be accomplished by an open laparotomy, by laparoscopy, or robotically.
Transperitoneal vesicovaginal fistula repair—Access to the fistula and its closure involves entry into the peritoneal cavity. This may be accomplished by an open laparotomy, by laparoscopy, or robotically.
Transvesical vesicovaginal fistula repair—Access to the fistula and its closure involves separate entry into the bladder (excluding entry through the fistula itself). This may be accomplished via a retropubic or a transperitoneal approach.
Urethrovaginal fistula—An abnormal communication between the urethra and the vagina.
Vaginal vesicovaginal fistula repair—Access to the fistula and its closure is accomplished through the vagina.
Vesicovaginal fistula—An abnormal communication between the bladder and the vagina.
INTRODUCTION
It is likely that women have suffered from urogenital fistulas throughout human existence as a consequence of childbirth. From an anthropologic perspective, humans experience difficult birthing requiring assistance primarily due to pelvic adaptations resulting from a trade-off between the evolutionary pressures of large brain size and bipedal biomechanics. Findings of a vesicovaginal fistula (VVF) have been identified in mummified remains from ancient Egypt. Since the mid-19th century, the evolution of surgical management of urogenital fistulas as described by Marion Sims, Thomas Emmet, Howard Kelly, and others has had a lasting influence on the development of our specialty.
It has long been recognized that women with VVF are severely afflicted physically, socially, and emotionally owing to the constant uncontrollable dribbling of urine. In the developing world, VVFs are most commonly noted as a consequence of prolonged labor. Perhaps a hundred years ago the situation was very similar in the (currently) developed world; however, due to dramatically improved access to expert obstetrical care, VVFs are now primarily acquired iatrogenically, mostly following hysterectomy. Providers and patients experience a vastly different set of circumstances in these two settings. In the latter, which is the primary focus of this chapter, patients are often litigious, yet they remain among the most grateful once their condition is explained and cured. Although the published literature regarding urogenital fistulas is extensive, it remains dominated by retrospective case series and expert opinion. The various types of urogenital fistulas are listed in Table 43.1 based upon anatomic involvement. This chapter primarily discusses vesicovaginal and urethrovaginal fistulas encountered in gynecologic and urogynecologic practice with a brief overview of obstetrical fistulas.
TABLE 43.1 Anatomic Classification of Genitourinary Fistulas | ||||||||||||||||||||
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ETIOLOGY AND EPIDEMIOLOGY
Genitourinary fistulas can be congenital or acquired. Congenital fistulas are exceedingly rare, with only a few case reports in the literature. Most reported cases are associated with other urogenital anomalies. Acquired fistulas may be the result of childbirth, pelvic surgery, malignancy, irradiation, infection, and an assortment of unusual presentations (Table 43.2). This section discusses obstetrical and nonobstetrical urogenital fistulas. The nonobstetrical fistula portion will further discuss the following issues associated with urogenital fistula etiology and epidemiology: hysterectomyassociated cystotomies, urogynecologic and other gynecologic procedures, urethrovaginal fistulas, and an assortment of miscellaneous circumstances that have been reported in the literature.
Obstetrical Urogenital Fistulas
In the developing world, the most common predisposing factor is prolonged, obstructed childbirth, accounting for over 80% of genitourinary fistulas in these regions. These fistulas develop from the resulting necrosis of the vaginal and bladder wall and, therefore, are large and often associated with other related damages. These circumstances have become exceedingly rare in developed countries owing to improvements in access to and delivery of skilled obstetric care. Ibrahim et al. report that the mean age at diagnosis was 15 years, patients were in labor for 4 days on average, and the fetus died in 87% of cases. These findings are similar to another single-institution series from Nigeria, where 79% of fistula patients had labors that lasted over 2 days, and 21% had been in labor for 4 or more days during the index pregnancy associated with the injury. The fetal fatality rate in these cases was 92%. In a rural, population-based study of parturients in Senegal, the incidence rate was 124 per 100,000 deliveries, whereas no fistulas were noted in six major cities in West Africa. It is estimated that over 33,400 new cases of obstetric fistulas occur annually in sub-Saharan Africa, with an incidence of over 120 per 100,000 births. Constitutional risk factors include short stature, lower
education and socioeconomic levels, and young maternal age. Circumstantial contributing factors include a very high rate of home births attended to by unskilled birth attendants, wherein only 35% of deliveries in Nigeria are attended by trained personnel. Late presentation in northern Nigeria is primarily related to lack of husband’s permission followed by transportation difficulties (distance, nonavailability of vehicle, and bad roads). The general lack of hospital resources including surgical supplies and reliable electrical power have been cited as contributing to delayed cesarean section for those who need it.
education and socioeconomic levels, and young maternal age. Circumstantial contributing factors include a very high rate of home births attended to by unskilled birth attendants, wherein only 35% of deliveries in Nigeria are attended by trained personnel. Late presentation in northern Nigeria is primarily related to lack of husband’s permission followed by transportation difficulties (distance, nonavailability of vehicle, and bad roads). The general lack of hospital resources including surgical supplies and reliable electrical power have been cited as contributing to delayed cesarean section for those who need it.
TABLE 43.2 Conditions Associated with Development of Urogenital Fistulas | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Hilton reviewed VVFs in developing countries and outlined management strategies to include immediate catheter drainage as long as the tract has not yet epithelialized, perhaps even prophylactically following obstructed labor with evident vaginal sloughing. Attention to adequate vulvar skin care, nutrition, lower extremity rehabilitation, and counseling are important adjuncts in the care of obstetrical fistula patients. Arrowsmith et al. similarly remind us of the spectrum of additional trauma sustained by the fistula patient and the need to address more than just the “hole in the bladder.” Additional concurrent injuries may include and result in amenorrhea, total urethral loss, stress incontinence, hydronephrosis, renal failure, anorectal injury, cervical destruction, vaginal stenosis, nerve damage affecting mobility, and other physical maladies. The psychosocial toll is equally devastating with divorce, separation from family and social support structures, worsening economic hardship, isolation, and malnutrition being commonplace.
Surgical correction is curative in the first operation for obstetric VVF in about 80% of cases. Multiple attempts may be necessary to achieve a success rate over 95% for large fistulas. As the reality and complexity of this global tragedy is realized, solutions are suggested for its prevention that include improving the stature of women and access to competent routine and emergency obstetrical care as well as family planning services. Both global and regional economic and political actions will be necessary to effect meaningful and lasting change.
Other obstetric events and procedures have been noted to be associated with urogenital fistula formation worldwide. Cesarean section, especially in patients who have had prolonged, obstructed labor, may result in formation of a vesicouterine fistula (Youssef syndrome). The classic presentation is that of cyclical hematuria (menouria), amenorrhea, and urinary continence, but it may also present with total urinary incontinence with normal menstruation and represents 1% to 4% of all genitourinary fistulas. Vesicovaginal fistulas have also been reported following cesarean section, with or without associated hysterectomy. Even more rarely reported are vesicocervical, urethrovaginal, ureterovaginal, and ureterouterine fistulas following cesarean section. Operative vaginal delivery may rarely result in vesicouterine fistula in a patient undergoing vaginal birth delivery after cesarean section. Similarly, cervical cerclage placed for the treatment of cervical insufficiency has been associated with vesicovaginal and vesicocervical fistulas. A recent case series and pooled analysis suggests that previous cervical procedures (prior cerclage or cervical conization), prior cesarean delivery, and use of the McDonald technique (which does not involve a bladder dissection as with the Shirodkar technique) may play a role in the formation of urogenital fistula in these cases.
Although not an obstetrical practice, the traditional tribal practice of “gishiri cutting” is associated with formation of urogenital fistulas and is common in many parts of northern Nigeria. It involves cutting the anterior vagina with a razor or knife blade and has been noted to be the primary cause of fistula formation in 13% to 15% of cases. In more recently reported series in areas where gishiri cutting was reported, urogenital fistula was noted in 2.3% to 6.2% of cases.
Nonobstetrical Urogenital Fistulas
Nonobstetric urogenital fistulas have been reported as a consequence of gynecologic, urologic, and general surgical procedures and are the most commonly seen in developed countries. Various manifestations of urogenital trauma, certain medical conditions, and even medication instilled into the bladder have also been associated with subsequent development of urogenital fistulas.
Hysterectomy is the most common surgical procedure associated with a VVF. In a retrospective review of the Mayo Clinic experience regarding the treatment of 303 women with genitourinary fistulas, 190 were vesicovaginal. Of these, 156 (82%) were associated with hysterectomy (mostly abdominal), 19 (10%) with cesarean section or forceps delivery, and 6 (3%) each with radiation and with trauma.
Harkki-Siren et al. reviewed the incidence of urinary tract injuries from a Finnish national database of 62,379 hysterectomies with a VVF prevalence of 0.8 per 1,000. In a nationwide registry-based cohort study from Sweden that included all hysterectomies performed for benign indications over 30 years (n = 182,641), the prevalence of surgically managed genitourinary fistulas was 1.1 per 1,000. This is the same rate reported in a retrospective study of two institutions in the
United States but has been reported as high as 3.0 per 1,000 in one of those institutions.
United States but has been reported as high as 3.0 per 1,000 in one of those institutions.
In a retrospective cohort study of 343,771 hysterectomies in the English National Health Service from 2000 until 2008, the overall urogenital fistula (vesicovaginal and urethrovaginal) rate was reported to be 1.3 per 1,000 within the year following surgery. Rates were noted to vary by the procedure type and the indication, with the highest rate in patients undergoing radical hysterectomy due to cervical cancer (11.5 per 1,000) and the lowest for vaginal hysterectomy due to prolapse (0.26 per 1,000). Most interesting was a subanalysis of abdominal hysterectomy for benign conditions excluding prolapse, where a 46% increase in the risk of fistula rates was noted over the course of the study itself from 1.5 per 1,000 in the first 2 years to 2.2 per 1,000 in the last 2 years of the study. See Table 43.3 for a summary of the various epidemiologic studies discussed.
As previously noted, hysterectomy for cancer is associated with an increased risk of fistula formation. In a retrospective study of 536 patients who underwent a radical hysterectomy due to cervical cancer, a VVF rate of 2.6% and a ureterovaginal fistula rate of 2.4% were reported. Risk factors included cancer stage, intraoperative bladder injury, diabetes, and postoperative surgical site infection. Vaginal cancer shows a high likelihood of fistula development (both vesicovaginal and rectovaginal) with no association to radiation therapy.
Hysterectomy-Associated Cystotomy and Vesicovaginal Fistula Formation
The association of a cystotomy sustained at the time of hysterectomy (recognized or not) and subsequent development of a VVF has long been noted but is nonetheless complex (see further discussion under Pathogenesis). A review of published articles reporting on cystotomies during gynecologic surgery showed that the rate of cystotomy is significantly increased in series that employed routine cystoscopy rather than the traditional intra- or postoperative diagnosis on which the other studies relied. These disparate rates of bladder injury continue with two distinct single-institution studies that employed routine cystoscopy at the time of hysterectomy, reporting a cystotomy rate of 2.6% to 2.9%, while estimates from a US national hospital discharge database-derived study reported bladder injury rates of only 0.7% to 1.4% depending on the type of hysterectomy. Although one cannot conclude that the two- to threefold difference in cystotomy rates is due to detection bias, it is not unreasonable to consider that some bladder injuries may go undetected during hysterectomy, which may contribute to the overall posthysterectomy VVF rate.
TABLE 43.3 Prevalence of Vesicovaginal Fistula by Type of Hysterectomy | ||||||||||||||||||||||||||||||||||||||||||||||||
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Even when a cystotomy is immediately recognized and repaired, a subsequent VVF may still occur. In their data on over 43,000 total abdominal hysterectomies, Harkki-Siren et al. report failure of primary bladder repair 18% of the time. In a case-control single-institution study of 1,317 benign hysterectomies, which included routine cystoscopic evaluation, 34 cystotomies were recognized and repaired, but among those, four patients (11.8%) developed a VVF. The degree of bladder injury retrospectively assessed by using the American Association for the Surgery of Trauma (AAST) system was found to be strongly associated with subsequent fistula formation despite cystotomy repair. The AAST grading system is used to describe the degree of injury to the bladder using the location and size of the defect with higher grades denoting worse trauma. Of highest risk are larger extraperitoneal (>2 cm) injuries, any intraperitoneal bladder injuries, and injuries involving the bladder neck or the trigone. Additional associated risk factors for occurrence of a VVF following cystotomy and repair include larger uterus, longer operative time, and longer hospital stay. A trend was noted when the hysterectomy was associated with greater than 1 L blood loss and for tobacco use. The strong association of bladder injury severity with subsequent VVF formation persisted in a subsequent expansion of this original study. There were 5,698 hysterectomies in the combined cohort where 102 cystotomies were diagnosed and repaired. Of these, there were six VVFs (5.9%) identified.
Urogynecologic Procedures
Due to the immediate proximity of the lower urinary tract to the operative field in surgeries for the treatment of urinary incontinence, pelvic organ prolapse, and other pelvic floor disorders, there have been reports of both vesicovaginal and urethrovaginal fistulas with these types of surgery. Surgeries for the treatment of stress urinary incontinence have been implicated, including Burch colposuspension, bone-anchored cystourethropexy, Stamey bladder neck suspension, transobturator tape, and retropubic tension-free vaginal tape procedures.
Surgery for anterior prolapse occurs adjacent to the bladder and may result in immediate or delayed injury to the lower urinary tract. Anterior colporrhaphy has been associated with VVF only in case reports regarding fistula repairs. In a single surgeon case series of 519 anterior colporrhaphy patients (with Kelly-Kennedy urethropexy for the treatment of stress incontinence), the authors reported two urethrovaginal fistulas but no VVFs. Mesh kit procedures for the treatment of anterior prolapse have been associated with VVFs by several investigators. The incidence of VVF from trocar-based mesh kit surgery used for the treatment of anterior prolapse has been noted to be 0.3% in a large series. A recent case report noted a ureterovaginal fistula 28 days following a transobturator mesh kit surgery for anterior prolapse. A case report of a VVF following total abdominal hysterectomy with sacrocolpopexy for uterine prolapse noted that the fistula was adjacent to the distal edge of the colpopexy mesh.
Urethrovaginal fistulas have been associated with each of the various forms of midurethral (mesh) slings, vaginal urethropexies, and even periurethral bulking injections. With the increasing popularity of midurethral slings for the treatment of stress incontinence, reports of associated urethral injury and urethrovaginal fistulas have been accumulating. A literature review identified 3 VVFs and 11 urethrovaginal fistulas with retropubic and transobturator approaches implicated in both fistula types. The reviewed literature was insufficient to estimate the rates of urethrovaginal fistulas.
Urethrovaginal fistulas may occur as a consequence of urethral diverticulum repair. Review of available series, ranging from 18 to 85 patients each, reveals that urethrovaginal fistula develops in 1.2% to 7.8% of patients undergoing vaginal repair of a urethral diverticulum.
Other Gynecologic Procedures
Additional gynecologic procedures associated with urogenital fistulas, although with greater rarity (see Table 43.2), include myomectomy, loop excision of the cervical transformation zone for cervical intraepithelial neoplasia, and voluntary interruption of pregnancy. Fistulas are noted following radiation therapy for gynecologic cancers and uterine artery embolization for leiomyomatous uteri.
Urethrovaginal Fistula
Urethrovaginal fistulas are less common than are VVFs, with an incidence ratio of 1 per 8.5. In the developed world, the most common predisposing event is surgery for urethral diverticulum, anterior vaginal prolapse and incontinence, radiation therapy, or trauma. Operative vaginal delivery and cesarean section also have been reported to precede urethrovaginal fistula formation. There has been an increase in urethrovaginal fistula formation related to the increased use of suburethral slings in the treatment of stress incontinence (please see subsection on Urogynecologic Procedures).
Miscellaneous Circumstances
An assortment of presentations and conditions can be found in the literature associated with urogenital fistulas mostly in the form of case presentations. These include Behçet syndrome; infections such as schistosomiasis, tuberculosis, lymphogranuloma venereum; endometriosis; accidental trauma; sexual trauma; masturbation; and a variety of retained foreign objects. Bladder calculi are found to be rarely associated with long-standing fistulas but not considered etiologic. Additional gynecologic associations include neglected diaphragm, neglected pessary, intrauterine device, and a ureteral wall stent used to treat a ureteral stricture. Intravesical instillation of mitomycin C has been reported to be associated with urogenital fistula formation.
PATHOGENESIS
The pathophysiologic mechanism of fistula formation is not completely understood. Etiologies have been proposed based on interpretation of the epidemiologic data and risk factors previously discussed. Vascular compromise and subsequent epithelial necrosis of the intervening vaginal walls are indisputable in cases of prolonged obstructed labor where the presenting fetal vertex compresses the vaginal walls against the pubic symphysis. If this pressure is present for a sufficient period of time, even once relieved, the affected vaginal, bladder, and/or urethral walls undergo necrosis and sloughing, thus creating the abnormal (often large) communication between adjoining viscera.
The precise pathophysiology of nonobstetrical urogenital fistulas is somewhat less obvious, but can likely also be understood in terms of abnormal healing associated with microvascular compromise coincident with posterior bladder/anterior vaginal wall injury. From empirical evidence, we know that small-sized bladder perforation in the non-gravity-dependent areas of the bladder rarely if ever results in any fistula formation. Consider suprapubic catheters that are removed with initial formation of a vesicocutaneous tract that almost inevitably heals without further intervention, as well as retropubic tension-free tapes that are found perforating the anterior and anterolateral bladder only to be repositioned with little to no consequence, even without prophylactic catheter drainage. On the other hand, the dependent area of the bladder is more prone to fistula formation due to its closer proximity to the vagina and possibly the effect of gravity and the near-constant presence of urine in this part of the bladder.
Experimental evidence further shows that not all injuries result in VVF formation, even in the dependent portion of the bladder. Meeks et al. demonstrated in a rabbit model that fistula formation did not occur when figure-of-eight absorbable sutures were placed incorporating full-thickness bladder wall and vaginal cuff during a hysterectomy. In a laparoscopic dog model, none developed a fistula after bipolar cautery injury to the bladder base nor when absorbable sutures were placed through the bladder and vaginal cuff during a laparoscopic hysterectomy. Fistula formation, however, was noted in the dogs that had a monopolar cautery-induced bladder base laceration and had repair either with single-layer absorbable suture in the normal fashion or with suture that incorporated the anterior vaginal wall. No differences were found histologically in the specimens that primarily showed inflammation, fibrosis, foreign body giant cell reaction, and recanalization of thrombus. It should be noted that these animal models of hysterectomy, because of anatomic differences, do not require any dissection of the bladder off the uterus and in that respect may be different from humans undergoing total hysterectomy.
From the aforementioned data, vascular or microvascular compromise may be the common pathway to fistula formation, which then leads to localized impairment of healing that allows the formation of an epithelialized tract between the two adjacent organs. Such microvascular compromise may aid in the understanding of urogenital fistulas caused by local infection or even subacute infection when foreign materials (suture, mesh, etc.) or electrocautery are used, as well as aid in the understanding of radiation-associated fistulas. Thus, in posthysterectomy urogenital fistulas, the mechanisms involved may be more complex than the previously assumed “undiagnosed bladder injury” or “inadvertently placed suture” that many have previously suggested. Further research into the pathophysiology is needed to elucidate the mechanisms at work in such circumstances.
CLINICAL PRESENTATION
The classic presentation of urogenital fistula is continuous urinary leakage from the vagina several days or weeks following pelvic surgery. This may occur in the absence of urinary urgency, Valsalva maneuvers, or changes in body position. The degree to which leakage presents depends primarily on the precise location and size of the fistula, perhaps the pliability and healing of the surrounding tissue, and the condition of the rest of the vagina. Patients have a spectrum of leakage from truly continuous to intermittent primarily at bladder capacity with attendant urinary odor. Although it is generally accepted that the larger the fistula, the worse the leakage, even small fistulas leak significantly. In developed countries, an antecedent gynecologic, urologic, or general surgical procedure involving the pelvis will often be noted. Delivery by the operative vaginal or, more commonly, cesarean section route may precede the onset of symptoms.
The majority of cases will present in 1 to 10 days following surgery and nearly all by 30 days, although the author has seen patients manifest symptoms as much as 3 months postoperatively. The increasing prevalence of multiple procedures undertaken at the same time for complex pelvic floor disorders (often by multiple surgeons) may complicate the diagnosis of subsequent fistula formation, related to multiple potential sites of injury, preexisting symptoms, and added potential postoperative urinary complications. Indeed, subsequent anti-incontinence procedures have been mistakenly done believing the cause of leakage is stress incontinence. Other potential causes of postoperative urinary leakage should be considered and ruled out, as listed in Table 43.4.
Many patients develop coexisting urinary tract infections and symptoms of frequency, urgency, and dysuria. The predominant organism is Escherichia coli in most cases. Urinary leakage from any genitourinary fistula may be accompanied by hematuria and rarely may have associated stones.
Vesicouterine fistulas tend to present with cyclic hematuria, and if the fistula is located above the cervix, amenorrhea may occur if all the menstrual blood is redirected into the bladder because of a closed cervical canal. Patients with coexistenting mesh erosion into the bladder experience urgency, frequency, voiding dysfunction, and pain. If there is concurrent erosion into the vagina, coital discomfort and a vaginal discharge may occur as well.
Urethrovaginal fistula may present either as continuous vaginal leakage or vaginal voiding either during or just following micturition. This depends primarily on the location of the fistula whether it affects the continence mechanism or not. Vaginal bleeding and dyspareunia may also present concurrently regardless of the fistula’s location and may be exacerbated by foreign material associated with the preceding surgery (mesh, graft, suture, etc.).
Any significant urine leakage for even a short period of time may result in significant irritation of the vagina, the skin of the vulva, or perineum. This often occurs, despite the patient’s attempt at frequent cleansing. Among obstetrical fistula patients, dermatitis symptoms were noted in 20% of patients. If urine leakage persists, severe perineal dermatitis may result owing to exposure of the skin to ammonia. Phosphate crystallization may precipitate on the vagina and vulva, further irritating the area.
TABLE 43.4 Differential Diagnosis of Postoperative Urinary Incontinence | |
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PREVENTION
Since the occurrence of a cystotomy is considered a risk factor for subsequent fistula formation, prevention is discussed primarily in terms of preventing a cystotomy (primary prevention) or adequately detecting and repairing one if it occurs (secondary prevention). Careful consideration of the bladder, trigone, and ureteral anatomy in relation to the anterior vagina, uterus, and cervix is important to maintain during each step of any hysterectomy, but especially with a total hysterectomy (Fig. 43.1).
Anatomically, the bladder base overlies the uterine isthmus and the cervix, the bladder trigone is positioned anterior to the upper third of the vagina, and the external cervical os is proximal to the base of the trigone (the interureteric ridge). During a simple hysterectomy, mobilization of the bladder does not involve the upper third of the vagina and therefore rarely puts the trigone at risk. A subtotal (supracervical) hysterectomy requires no bladder mobilization and indeed results in dramatically fewer fistulas even in large series (see Table 43.3). This is not the case, however, with anterior colporrhaphy or vaginal paravaginal repair, where the anterior vaginal dissection is carried more distally and laterally upon the vagina, indeed involving its middle and upper thirds.
The likelihood of cystotomy is reduced by avoiding blunt dissection at the time of bladder mobilization during hysterectomy (or anterior repair), especially when the vesicovaginal space is scarred from prior cesarean section or other surgery. The precise direction of forces cannot be controlled as accurately when blunt dissection is used, when compared with sharp dissection. Gentle traction and countertraction are helpful in dissecting the correct plane and thereby preventing direct bladder injury, as is utilizing an intrafascial hysterectomy technique. Another cause of bladder injury may be direct trauma by retractors, particularly during vaginal hysterectomy; retractors should always be used with appropriate caution. As previously reviewed (see Pathogenesis section), experimental data suggest a detrimental effect of using monopolar electrocautery. As such, one should consider electrocautery with monopolar current in the vesicovaginal space only after carefully considering the risks and benefits.
If during the course of a hysterectomy or any pelvic surgery, a bladder injury (cystotomy) occurs, it is critical to diagnose and properly manage it prior to the conclusion of the surgery so as to minimize the likelihood of subsequent fistula formation (secondary prevention). See Steps in the Procedure for the surgical steps of cystotomy repair. In addition to careful inspection of the operative field, cystoscopy is often recommended to assess for bladder and ureteral injury following hysterectomy and routinely recommended after surgery for pelvic prolapse or urinary incontinence. The routine use of cystoscopy at the time of hysterectomy remains controversial by some, yet recommended by others. The alternative to routine cystoscopy is performing it as needed when a suspicion for injury arises as may occur with new-onset gross hematuria, while the bladder is catheterized or visualization of fluid in the operative field. Studies in which routine cystoscopy has been performed report a bladder injury detection rate of only 35% to 50% when relying on visualization alone.
 FIGURE 43.1 Anatomic relations of the bladder, rectum, uterus, and vagina. The right ureteral orifice and interureteric ridge are denoted. Note that the cervix and the anterior cervicovaginal sulcus are at a position higher than the interureteric ridge, which explains why the simple posthysterectomy vesicovaginal fistulas are supratrigonal at the level of the vaginal cuff. |
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In the event of a cystotomy, the location, extent, and size as categorized in the AAST grading system previously discussed may be an important factor in assessing prognosis of the repair of a posterior bladder injury. Also, as previously discussed in the Pathogenesis section, a small anterior bladder injury does not result in urogenital fistula formation as observed following removal of suprapubic catheters or trocar injuries from retropubic midurethral slings. Since these injuries are approximately 0.5 cm in diameter, any bladder injury greater than that may be considered for primary repair versus longer catheter drainage to allow for spontaneous healing. Owing to the dependent position of the bladder base however, any significant injury in the posterior bladder requires consideration of suture closure and bladder drainage.
Once a cystotomy is recognized, it may be repaired immediately or delayed until the hysterectomy or other surgical procedure is completed. The benefit of immediate repair is that blood and urine do not continually flow into the surgical field; however, with continued surgery and retraction, there may be potential compromise to the fresh suture line, and this should be meticulously avoided. Cystoscopy, when an injury is first suspected, is helpful in delineating the exact location and extent of the injury as well as distance to the ureters and trigone. Adequate dissection of the bladder off the vagina is usually necessary to ensure tension-free closure and allow sufficient mobilization for a second layer. Careful inspection of the cystotomy is critical to identify the true borders of the defect. Due to the inherent pliability and redundancy of the bladder, repair without careful delineation of the edges may miss a particularly well-hidden portion of the defect, which could lead to nonhealing and subsequent VVF formation. The first layer can be accomplished with 2-0 or 3-0 absorbable suture placed in an interrupted or running fashion (Fig. 43.2A). There is controversy regarding whether this first layer can be placed through the mucosa or should remain extramucosal. It is thought that the extramucosal technique may decrease the likelihood of subsequent fistula formation and perhaps prevent bladder stone formation, although this has not been demonstrated, whereas excluding the urothelial edge may result in bleeding from it. Results from an experimental laparoscopic hysterectomy model of electrocautery-induced bladder injury with laparoscopic repair in dogs suggest that double-layer closure is superior to single-layer closure in preventing VVF. The second layer placed to imbricate the first is thought to diminish tension on the suture line. A third layer of closure usually can be achieved with the peritoneum either vaginally or abdominally (Fig. 43.2B, C). Cystoscopy is important to evaluate ureteral and bladder integrity following completion
of the repair and to ensure there is no significant hematuria, which can obstruct catheter drainage with the formation of clots. Cystoscopy should be done with minimal bladder filling to avoid tension on the suture line.
of the repair and to ensure there is no significant hematuria, which can obstruct catheter drainage with the formation of clots. Cystoscopy should be done with minimal bladder filling to avoid tension on the suture line.
 FIGURE 43.2 Closure of cystotomy associated with total abdominal hysterectomy (abdominal view). A: Initial layer is closed with a running suture. B: An imbricating second layer is being placed using interrupted stitches. C: A third layer covering the repair with peritoneum. |
Transurethral or suprapubic catheter drainage must prevent bladder filling to avoid exerting tension on the suture line that would otherwise occur when the bladder fills. The lack of reliable postoperative catheter drainage as a significant cause of failure of fistula repair was discussed at length in 1852 by Sims in his landmark paper regarding urogenital fistulas. Judgment should be exercised regarding duration of drainage, based on the extent of injury, its location, the security of the closure, and any factors that may impact the normal healing process, but generally should be for 7 to 10 days. Some advocate use of a cystogram prior to catheter removal; however, subsequent VVF in the face of a normal cystogram has been noted anecdotally, calling this extra step into question. A retrospective study of bladder injury in the trauma setting concluded that in patients undergoing simple intraperitoneal bladder injury management, routine follow-up cystograms did not affect clinical management, while all extraperitoneal and complex intraperitoneal injuries required follow-up cystograms.
DIAGNOSIS AND EVALUATION
Often, the diagnosis of nonobstetrical urogenital fistula is straightforward based on history and demonstrable pooling of urine in the vaginal vault; occasionally, however, the diagnosis is elusive. In all cases, it is necessary to evaluate the fistula with regard to its size, precise location, degree of epithelialization, whether it is simple or complex, accessibility, and the overall health status and mobility of the surrounding tissues. In the instance of a recurrent fistula, precise knowledge of prior conservative management and review of the surgical description of prior repair attempts are extremely helpful for choosing the most appropriate route, type, and timing of the repair.
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