Version May 2024
INTRODUCTION — Obstetric fistulas are abnormal communications between the genital tract and the urinary tract (urogenital fistula) or the gastrointestinal tract (most commonly, rectovaginal fistula) that occur as the result of obstetric trauma, typically from prolonged obstructed labor. These fistulas result in urinary and/or fecal incontinence, which can result in the patient being shunned by her community. Obstetric fistula is uncommon in countries in which the health care infrastructure is well developed.
Vesicovaginal fistulas, particularly obstetric fistulas, in resource-limited settings are reviewed here. General information regarding genitourinary fistulas is discussed separately. (See "Urogenital tract fistulas in females".)
In this topic, when discussing study results, we will use the terms "woman/en" or "patient(s)" as they are used in the studies presented. However, we encourage the reader to consider the specific counseling and treatment needs of transgender and gender expansive individuals.
EPIDEMIOLOGY — The incidence of vesicovaginal fistulas in resource-limited countries is difficult to ascertain and studies report rates of fistulas arising from obstetric causes and not from other etiologies. The World Health Organization estimates that there are 130,000 new cases of obstetric fistula each year, calculated from an assumption that fistula is likely to occur in 2 percent of the 6.5 million cases of obstructed labor that occur in developing countries [1]. A prospective study of maternal morbidity in sub-Saharan Africa reported an annual incidence of 33,000 obstetric fistulas [2]. The prevalence of obstetric vesicovaginal fistula is directly related to the prevalence of obstructed labor and the accessibility of emergency obstetric care, including facilities capable of performing cesarean delivery. Obstetric fistula closely parallels maternal mortality because both conditions are directly linked to the accessibility of emergency obstetric care. The fistula problem is most severe in sub-Saharan Africa because maternal mortality is highest there, but fistulas are also found in other parts of the world where fertility is high, the status of women is low, and obstetric services are poor, such as Afghanistan, Pakistan, Bangladesh and parts of India. Obstetric fistula is a disease of poverty. Some have classified it as one of the "neglected tropical diseases" [3].
By contrast, in industrialized countries, obstetric fistulas are rare. In the United States, estimates of vesicovaginal fistula formation range from less than 0.5 percent after simple hysterectomy to 10 percent after radical hysterectomy [4-6]. Similar data from the English National Health Service show a vesicovaginal or urethrovaginal fistula occurring after 1 in 788 hysterectomies, with a higher rate of 1 in 87 occurring after radical hysterectomy for cervical cancer [7]. In a 20-year cohort study of fistulas from Norway, there were only four genitourinary fistulas related to obstetric care in 116,389 deliveries, and these were related to complications of cesarean section, cervical cerclage, and uterine rupture, and not from neglected prolonged labor [8]. According to data in the United States National Hospital Discharge registry, out of 2,329,000 operations performed on the female urinary and genital systems in 2007, there were fewer than 5000 procedures for vesicovaginal fistula repair [9]. In wealthy countries, vesicovaginal fistulas largely result from complications of surgery, not from neglected obstructed labor.
Resource-limited countries lack the ability to treat all patients who currently have obstetric fistulas. It is estimated that a million or more women in sub-Saharan Africa currently have an unrepaired vesicovaginal fistula, with between 30,000 and 130,000 new cases occurring each year [1,2]. The current total capacity for fistula repair in sub-Saharan Africa is still quite limited, perhaps around only 10,000 cases per year [10]. This remains inadequate to meet the existing clinical needs.
ETIOLOGY AND PATHOGENESIS — In resource-limited countries, particularly in sub-Saharan Africa, vesicovaginal fistulas are much more common than in industrialized countries [1,2]. Obstetric trauma from prolonged, obstructed labor is the cause of the majority of vesicovaginal fistulas in these settings. The incidence of postoperative fistulas has increased as pelvic surgery has become more accessible. As an example, in a series of 164 genitourinary fistulas reported from a teaching hospital in Ghana, nearly 92 percent were the result of obstetric complications and 7 percent were complications of difficult hysterectomy for large uterine leiomyomata [11]. Other causes of vesicovaginal fistula include traditional practices (eg, genital cutting or vaginal "salt packing") and sexual violence against women (especially in conflict zones). The injury is compounded by economic and societal issues that impact the accessibility to and quality of health care.
By comparison, in resource-rich countries, when a fistula occurs, it is usually the result of a complication of pelvic surgery [12,13]. Less frequently, a fistula arises as a complication of surgical treatment of cancer or radiation therapy.
Obstructed labor — Labor becomes obstructed when the fetal head can no longer advance through the birth canal despite strong uterine contractions. All pregnant women are potentially at risk because obstruction can develop during any labor. When obstructed labor is not diagnosed and treated in a timely fashion, obstetric fistula can develop as a result of pressure necrosis. In countries with poor maternal health services, several factors contribute to inadequate care and a delay in diagnosis and management of obstructed labor, and result in a high rate of obstetric fistulas. These factors include: low social, economic, and political status of women resulting in poor maternal health services; delivery at home with care by untrained birth attendants; limited or no access to emergency obstetric services; infrastructure and economic barriers to travel; lack of or poor quality of secondary and tertiary health care services, and low quality health care in general [14].
●Mechanisms
•Obstetric fistula – An obstetric fistula develops at a point of tissue necrosis. The maternal soft tissues (bladder, vagina, cervix, rectum) become compressed between the boney plates of the fetal head and the maternal pelvic bones. With prolonged compression, tissue ischemia occurs and necrosis develops in the vagina and the connective tissues that separate the vagina from the bladder and rectum. Once they are necrotic, these tissues slough away and one or more fistulas are formed involving the vagina and the urinary and/or gastrointestinal tracts.
•Associated tissue injury – The tissue surrounding a fistula is also in poor condition. An obstetric fistula resulting from obstructed labor is not caused by laceration of otherwise healthy tissues that fail to heal properly; rather, the obstetric fistula is the product of a generalized "field injury" caused by tissue compression. Prolonged obstructed labor produces an extensive crush injury that destroys wide swaths of tissue in the pelvis and leads to fistulization. The margins of the fistula are often heavily scarred and devascularized, potentially complicating future surgical repair.
●Contributing factors – Many different factors contribute to the ultimate development of fistula and there is no specific duration of obstructed labor after which an injury occurs. Tissue necrosis is the final result of a complex set of interactions involving the amount of force exerted on the impacted tissues, the degree of distension of the bladder, the level in the pelvis at which labor has become obstructed, the blood flow through the affected tissues, the overall resilience of the tissues, and the amount of time these processes continue.
●Timing of onset – Most fistulas from prolonged obstructed labor will develop within the first two weeks after delivery, and sometimes the injury is immediately apparent after delivery in cases where labor has been extremely prolonged.
●Associated complications – The process of obstructed labor may also produce a broad spectrum of other maternal and neonatal injuries (eg, neurologic, musculoskeletal), referred to as the obstructed labor injury complex (table 1 and algorithm 1) [15]. Stillbirth rates of 84 to 93 percent have been reported by patients presenting with obstetric fistula [15,16].
Surgical complications — Urogenital fistulas following gynecologic surgery are typically a discrete injury to otherwise healthy tissue. Most posthysterectomy fistulas are small and are located at the vaginal cuff where the bladder was dissected off the lower uterine segment and cervix. A pool of urine leaking from the injured bladder prevents normal healing of the edges of the vaginal cuff, thereby allowing a fistula to form between the raw surfaces of the bladder and the vagina.
A small proportion of vesicovaginal fistulas in sub-Saharan Africa result from surgical complications usually associated with hysterectomy. Currently, access to surgical services is limited in many developing countries. As this access increases, the number of cases of fistula associated with surgery will increase [17]. As in industrialized countries, fistula is likely to remain a rare complication of pelvic surgery. (See 'Epidemiology' above.)
Fistulas associated with surgery can be regarded as "diseases of medical progress" [18]. This phenomenon is seen as medical care advances. Better obstetric care decreases the number of patients experiencing prolonged labor and access to other medical and surgical interventions increases [19]. As an example, in a series of 230 cases of vesicovaginal fistula in Bangkok, Thailand between 1969 and 1997, only 10 fistulas were due to prolonged or difficult childbirth; the rest occurred as complications of hysterectomy, radiation therapy, pelvic fracture, or other etiologies [20]. A follow-up study from the same institution, reporting an additional 45 patients with fistulas seen between 1998 and 2005, discovered that the vast majority of fistulas there were the result of laparoscopic hysterectomy, and that none in this latest series were the result of obstetric trauma [21].
Traditional practices — In some countries, a small number of obstetric fistulas result from injuries associated with traditional medical practices such as genital cutting or "salt packing" [22,23].
Various traditional forms of genital cutting continue to be practiced in many countries as a rite of passage to womanhood. There are now active campaigns throughout the world to eliminate these harmful practices, which nonetheless are still deeply entrenched in many cultures. These practices may result in a fistula through direct urogenital trauma at the time at which they are performed; only rarely do they cause a fistula by creating scarring at the pelvic outlet that obstructs normal vaginal delivery. The importance of genital cutting lies in the fact that it is a profound marker for the low social status of women in those societies where it is practiced. Genital cutting is a sign that the status of women is low, extreme poverty exits, educational services are lacking, high-quality obstetric services are not available, and a society has a poorly-developed infrastructure to meet women's health care needs [24]. (See "Female genital cutting".)
Salt packing is a traditional practice that is now rarely practiced, found largely in Arab countries. In this practice, the vagina of a postpartum woman is packed with mineral salts to "tighten it." It may create a fistula by direct chemical burning, particularly after a prolonged labor.
In some cases, genital cutting may be performed by traditional medical practitioners for what they perceive as therapeutic purposes based on their understanding of gynecologic or behavioral pathology. This form of genital cutting, referred to as gurya cutting in Niger, can result in genitourinary fistula by direct injury to the affected tissues [25].
Economic and societal issues — Economic, societal, and cultural factors contribute to the circumstances in which injuries that result in obstetric fistula occur (algorithm 1). These injuries overwhelmingly affect resource-poor, uneducated, and socially and politically disenfranchised patients. These conditions contribute to injury. A small number of fistulas result from sexual violence perpetrated against child brides who are not yet physically able (or emotionally ready) to have intercourse, from complications of unsafe abortion, or from atrocities committed to terrorize civilian populations in areas of armed conflict [22,23,26-28]. In addition, these factors hinder timely access to emergency obstetric and gynecologic services. The resulting injuries have been described as part of the "structural violence" that exists in these countries: the economic, political, legal, religious, and cultural forces that impact people living in marginal circumstances that prevent them from reaching their full potential [29-32].
PREVENTION — Obstetric fistulas are caused by delay in the diagnosis and treatment of obstructed labor. If obstructed labor is diagnosed promptly and effective treatment (cesarean delivery or operative vaginal delivery) is instituted, the cascade of injuries that characterize the obstructed labor injury complex can be avoided. The following is a useful conceptualization of the phases of delay that lead to maternal mortality and morbidity [33]:
●Delay in making the decision to seek care in an obstetric emergency
●Delay in arriving at a suitable health care facility once the decision to seek care has been made
●Delay in receiving appropriate care once the patient arrives at a health care facility
In developing countries, improved access to obstetric care and drainage of the bladder with a catheter after prolonged labor are useful preventive measures when they can be initiated.
EVALUATION AND DIAGNOSIS — Issues that are relevant to the clinical presentation, evaluation and diagnosis of women in resource-limited settings with an obstetric fistula are discussed here. The clinical manifestations, evaluation, and diagnosis of women with a urogenital fistula are discussed in detail separately. (See "Urogenital tract fistulas in females".)
An obstetric fistula should be suspected in women who present with a complaint of continuous urine loss beginning immediately following childbirth, particularly after a long labor. The amount of time from the onset of symptoms to the presentation of the patient to a health care provider depends on the patient's ability to access health care. There are many barriers to accessing a health care facility, particularly a facility that can provide treatment for a fistula [34]. These obstacles include patient awareness that treatment is available and where to find it, distance, expense, arranging care for children, and cultural and linguistic differences between patients and clinicians.
Physical examination — On pelvic examination, a continuous pool of urine is evident in most patients. Smaller fistulas, particularly ones that persist after previous attempts at repair, may not be so readily discernible. Simple digital examination is often sufficient to document the presence of a fistula, especially if large amounts of urine are pooling in the vagina, but examination of the vagina with a speculum and a good light source is mandatory prior to attempting surgical repair.
More than one fistula may be present, and they can occur in almost any location, depending on the point at which the progress of labor became obstructed and the types of interventions that were attempted prior to delivery. In some cases, the cervix or urethra may have been completely destroyed. The anatomy of the vagina may be completely distorted and dense scarring is often present, making the exact location of the fistula difficult to determine. Sometimes, the fistula may be easily diagnosed by palpating the defect in the bladder or rectum. In some cases, so much tissue may have been destroyed that the raw surface of the pubic bone may be palpated directly. Obstructed labor may result in total amputation of the proximal urethra. In such cases, upon digital palpation in the vagina, the finger can directly abut the pubic bone.
The presence of a fistula can usually be confirmed with a simple dye test using sterile water mixed with indigo carmine or methylene blue dye. These supplies are usually available at surgical hospitals in resource-limited countries. In general, cystoscopy is not needed in order to diagnose a vesicovaginal fistula in resource-poor settings, but cystoscopy is a useful tool to evaluate the bladder for other pathology, such as the presence of a bladder stone, which may occur in a patient with an obstetric fistula. In general, it is best to remove the stone and allow the bladder lining to heal before attempting fistula repair.
Classification — The location and size of the fistula, along with any complicating factors (eg, scarring, rectovaginal fistula) should be recorded in the patient's chart. There is no generally accepted international classification system for obstetric fistulas. The Goh classification system is most widely used [35]. The system has been validated by intra- and interobserver correlation and also appears to correlate well with surgical outcome [36,37]. The World Health Organization classification system is shown in the table (table 2).
MANAGEMENT — The mainstay of treatment for obstetric fistulas is surgical repair. A few fistulas, particularly if they are small and are diagnosed immediately after delivery, may heal spontaneously if an indwelling urinary catheter is placed and is allowed to remain for several weeks [38].
Management of obstetric fistula and other issues that are relevant to the management of women in resource-limited settings with an obstetric fistula are discussed here. General principles of the management of urogenital fistulas are discussed in detail separately. (See "Urogenital tract fistulas in females".)
Obstetric fistula repair
Operative conditions — The fundamental prerequisite for carrying out fistula repair operations in low-resource settings (whether the operations are done by local surgeons or by visiting doctors) is whether appropriate care can be delivered [39]. The operating surgeon should possess adequate skill to handle the anticipated difficulties of the case. Generally, this will mean that the surgeon has had significant previous experience in doing fistula repair operations in low-resource settings. If the operating surgeon or other medical staff do not speak the patient's language, a competent interpreter should be readily available. Adequate anesthesia (usually spinal anesthesia), lighting, intravenous fluids, medications (antibiotics, analgesics), suture material, and surgical equipment should be available. Access to blood products is desirable, but is not always possible in the circumstances under which care is often delivered. There should be a back-up plan for emergencies and adequate clinical coverage must be arranged in case the patient develops a postoperative complication and the operating surgeon is no longer available for consultation. There should be adequate perioperative nursing care, including the ability to monitor vital signs and catheter drainage in the immediate postoperative period, as well as provision for adequate pain relief. Patients should have adequate food, clothing, and shelter while they recover from surgery.
The presence of such resources is assumed when operations are done in hospitals in affluent countries, but they cannot be taken for granted when working in impoverished nations. In settings where the available resources are marginal, the wisest decision may be to cancel or postpone the operation, rather than to engage in risky practice. Particularly in complicated cases, the surgeon should recognize that what would normally be a minor complication in Europe or North America can end catastrophically if the resources commonly needed to deal with it are not available.
Preoperative preparation — A basic general medical screening of the patient should be performed prior to surgery. It is usually not necessary (and often is not even possible) to carry out an extensive preoperative medical work-up unless obvious physical signs and symptoms of significant systemic disease are present. Patients should be fit enough to undergo the operation. If they are not, the operation should be postponed. Active parasitic infections, such as malaria, should be treated preoperatively. If the patient is extremely anemic, it may be preferable to treat her with iron supplementation for several months, or intravenous iron if available, prior to attempted repair.
The patient should be washed thoroughly with soap and water before surgery, but no specific preparation of the fistula site is necessary other than what would normally be carried out in the operating room. Although most surgeons use prophylactic antibiotics (such as a single dose of gentamicin), there are currently no good data that demonstrate that this improves the outcome of fistula repair operations.
Procedure — The basic principles of obstetric fistula repair are [40,41]:
●Broad mobilization of the fistula so that it can be closed without tension at the site of the repair
●Water-tight closure of the injury
●Adequate bladder emptying in the postoperative period so that the suture line does not become over-distended and break down
Application of these principles to any individual case may be quite challenging, particularly if the fistula is complicated. Fistula repair surgery should be performed by an experienced pelvic surgeon.
●Exposure of fistula – The starting point for successful fistula repair is to visualize the entire fistula and expose it fully so that the surgeon is aware of the margins for closing it completely. The precise steps depend on degree of scarring and local pathology that is present. These steps will vary enormously from patient to patient. Generally, the initial incision is one that circumscribes the fistula so that the surrounding tissues can be adequately mobilized for closure. The next step is to mobilize the surrounding tissue. The edges of the fistula should be free enough that they can be brought together without tension on the suture line. Many attempted fistula repairs are unsuccessful because the fistula was not adequately mobilized at the initial dissection. For large fistulas, almost the entire anterior vagina may need to be mobilized, as well as dissection into the retropubic space of Retzius. In cases where there is heavy vaginal scarring, relaxing incisions in the surrounding scar tissue may be required to free up the fistula so that it can be closed. In many cases, this may require a generous mediolateral episiotomy that must subsequently be repaired.
●Closure of bladder wall – Once the fistula has been exposed and the surrounding tissues have been widely mobilized, the bladder wall is closed. The most important point is to make sure that the closure is water-tight or the repair will likely fail.
•Initial closure – Closure is typically accomplished using either interrupted sutures or a continuous running suture of delayed-absorbable material (eg, 3-0 polyglactin 910, Vicryl). The use of interrupted sutures has the advantage that should one suture fail, the entire suture line is not disrupted, as would be the case in a break involving a continuous running suture.
•Avoid permanent suture – Permanent suture should not be used for fistula repair unless it can reliably be removed 7 to 14 days after surgery. If permanent sutures are left in place, they will often become the nidus for the formation of a bladder or vaginal stone. Sutures left in place may also lead to breakdown of the repair and/or pain and discomfort.
•Possible imbrication suture – There is some debate as to whether a second layer of imbricating suture in the bladder wall is required. A second layer serves to buttress and support the initial closure, but if dense scarring or markedly reduced bladder capacity is present, it may not always be possible to place a second layer.
●Test bladder wall integrity – The integrity of the bladder wall closure should be tested. This is generally done by instilling a solution of sterile water colored with indigo carmine or methylene blue dye (5 to 10 mL in 500 mL of saline) into the bladder via a bladder catheter. The bladder should be filled with roughly 250 mL of fluid and the suture line carefully checked for leakage. If a leak is discovered, the repair must be revised until it is watertight; failure to do this virtually guarantees failure. As the United States surgeon J. Marion Sims noted in his classic 1852 paper on fistula repair, "if a single drop of urine finds its way through the fistulous orifice, it is sure to be followed by more and thus a failure to some extent is almost inevitable" [40]. The intention here is to fill the bladder to a reasonable volume to check the integrity of the repair, not to make it undergo a "pressure test," which could itself break down the repair by over-distension.
●Close vaginal epithelium – The vaginal epithelium is closed using either interrupted or running absorbable sutures. Absorbable sutures should be used if possible. Many surgeons place a vaginal pack for one or two days to improve hemostasis and provide support to the healing tissues.
●Additional surgical considerations
•Possible use of vascular flap – Use of a vascular tissue flap as an adjunct to repair is an ongoing controversy in fistula repair. The most commonly used flap is a bulbocavernosus fat pad interposition (Martius flap). Because the obstetric fistula results from a crush injury that involves a broad swath of tissue, the rationale for using a flap is to bring a fresh blood supply to the surgical field with the aim of improving wound healing. Another potential advantage of the use of full-thickness Martius skin grafts to close the vagina is that they may preserve vaginal depth and reduce the rate of postrepair vaginal stenosis [42]; however, patients who have undergone a repair using a Martius flap may develop stress urinary incontinence in 10 to 20 percent of these repairs [43]. At present, there seems to be a movement away from the routine use of bulbocavernosus flaps in obstetric fistula repair.
The available evidence regarding whether to use a vascular flap comes largely from observational studies. For example, a retrospective review of 46 obstetric fistula repairs in India compared those done with and without a Martius flap and found substantially better results in patients who had undergone a repair with a flap [44]. In contrast, a study of 440 fistula repairs done in Ethiopia with and without the use of a Martius flap found no significant difference in outcomes between the two groups [45]; the author attributed the high rates of success attained in both groups to the experience of the surgeon rather than the use of a flap.
Use of a vascularized pedicle flap, such as a gracilis muscle transposition flap or Singapore fasciocutaneous flap, has been reported in more complicated cases, such as those with broader areas of tissue loss or repeated prior failed attempts at fistula closure [46,47].
•Creation of neourethra – Fistulas in which the urethra has been transected ("circumferential fistula") or destroyed remain among the most challenging to repair. In many cases, an attempt is made to create a neourethra by mobilizing vulvar and labial tissues [48,49]. In some cases, it may be possible to mobilize a flap from the anterior bladder itself, roll it into a tube, and bring it down as a neourethra [50]. Patients who develop stress urinary incontinence after a vesicovaginal fistula repair, and particularly those who have stress incontinence after fistulas involving the urethra, may be candidates for some type of suburethral sling. When sling operations are performed, they should use the patient's own tissues (rectus fascia, fascia lata). Commercial "mesh kit" suburethral slings have no role in obstetric fistula surgery [51].
Postoperative care — At the end of the procedure, a bladder catheter is placed to avoid putting pressure on the repair by bladder distension. We prefer soft, flexible latex catheters to stiff silicone catheters.
Postoperative care after fistula repair is discussed separately. (See "Urogenital tract fistulas in females", section on 'Postoperative care'.)
OUTCOME AND COMPLICATIONS — Fistula surgeons have traditionally reported "success" as their ability to close the hole between the bladder and the vagina. From the obstetric fistula patient's point of view, however, "success" occurs only when the fistula is closed, when she has normal bladder storage and emptying functions, when she has regained normal sexual functioning, when her menstrual cycle has returned, when she has normal reproductive capacity often including the ability to have additional children, and when she is accepted once again as a full participating member of her local community and the wider society in which she lives. This is a very tall order indeed. "Success" lies in the eye of the beholder and the definition of success that is used is extraordinarily important. Because prolonged obstructed labor produces injuries at multiple levels, the only appropriate measure of success is a holistic one that sees the entire woman in her social context and not merely a "hole" to be closed by the surgeon.
The complexity of obstetric fistula repair varies across patients. The degree of scarring at the fistula site, the size of the fistula, and the extent to which the continence mechanism of the urethra and bladder neck is involved all appear to have considerable prognostic significance [37,52-54]. The World Health Organization has developed criteria for differentiating between simple and complicated fistulas that may be helpful in predicting surgical outcomes, but this system has not been validated (table 2) [55]. A different system defines surgery as easy, intermediate, or difficult based on a clinical scoring system [56]. Given the enormous variability in the types and kinds of fistulas that are seen, it is extremely difficult to compare outcomes. The best opportunity to correct the problem and close the fistula lies in the initial operation; the success rate drops steadily with subsequent repairs [56]. In a study of 384 women who completed a review 6 months after fistula surgery, the odds of having a closed and dry outcome decreased with the increasing number of surgeries [56].
Persistent incontinence after surgical repair — Persistent incontinence after fistula repair is either persistent incontinence from a fistula that has not been successfully closed or it represents transurethral incontinence from another source. It should not be assumed that postrepair incontinence is stress incontinence without further systematic evaluation.
Patients should be counseled preoperatively about the risk of persistent incontinence. The discrepancy between successful fistula closure and postoperative continence has been called "the continence gap" [57]. If, starting from her very first visit, the effort is made to help a patient develop realistic expectations about the results of surgery, this will be of great assistance when complications arise and outcomes are less than had been initially hoped. Particularly in low-resource settings where there is a huge disparity in education and knowledge between the patient and her caregivers, every effort must be made to communicate clearly and consistently as to what will happen and what she may expect. It is often extremely useful to provide "peer counseling," which refers to engaging a former fistula patient from similar socioeconomic circumstances who has been through surgery and recovery herself to explain the process to the patient and help serve as her guide through the process.
In general, there are three possible outcomes from a fistula repair operation: "closed and dry," when the fistula has been repaired and continence has been restored; "not closed," when the repair has not been successful; and "closed but wet," when the fistula has been closed, but the patient still experiences transurethral loss of urine [56]. In the past, it has often been assumed that these patients have "type III stress incontinence." Further investigation has demonstrated that this is often not the case. Patients who are still incontinent after successful fistula closure may have any number of reasons for their urine loss, including stress incontinence, detrusor overactivity, incomplete bladder emptying or urinary retention, the presence of a bladder stone, marked reduced bladder capacity, etc.
When postoperative incontinence is present, the cause must be identified. The first step is to determine if a fistula is still present. This is best done by performing a vaginal examination and a dye test. A catheter is inserted into the bladder, the urethra is compressed with a gauze pad to prevent leakage around the catheter, and the bladder is filled with a solution of colored saline or sterile water. Leakage through an unclosed fistula should be apparent (see "Urogenital tract fistulas in females", section on 'Dye test'). Examination may reveal leakage from the repair site or even a separate vesicovaginal fistula that had been inadvertently overlooked. In general, unless complete breakdown of the repair is obvious immediately after surgery, it is prudent to wait at least six weeks for optimal healing to occur before making another attempt at surgical repair. In such cases, continued catheter drainage may allow the fistula to heal, particularly if the defect is small.
Some women with continued incontinence may have a ureterovaginal fistula that was not accurately diagnosed before surgery. Use of oral phenazopyridine (to turn the urine orange) in combination with a dye test of the bladder can help to identify these defects. Facilities that can perform an intravenous urogram will be able to document a ureterovaginal fistula radiographically, but this technology is often not available in low-resource settings. The evaluation and treatment of this type of fistula are discussed separately. (See "Urogenital tract fistulas in females", section on 'Evaluation of suspected urogenital fistula' and "Urogenital tract fistulas in females", section on 'Ureterovaginal fistulas'.)
If extraurethral loss of urine through a fistula cannot be documented and the patient still has leakage, the patient should be evaluated for etiologies of transurethral urinary incontinence, including stress incontinence, detrusor overactivity, incomplete bladder emptying, or a bladder stone. Although not yet widely available in centers performing fistula surgery, equipment to perform urodynamic studies is likely to prove invaluable in making a precise diagnosis in women with postrepair incontinence [58].
Although it seems somewhat counter-intuitive, patients with obstetric fistula are at an increased risk of incomplete bladder emptying. Innervation of the detrusor muscle passes through the trigone, which is often injured in obstructed labor. The extensive dissection needed to mobilize the fistula at the time of closure may also contribute to neuropathic injury. Bladder emptying can be assessed by checking the postvoid residual urine volume, either by catheterization or the use of an ultrasonic bladder scanner (if available). (See "Postoperative urinary retention in females", section on 'Voiding trials'.)
A bladder stone develops in some patients following fistula repair, particularly if nonabsorbable sutures were used. Passage of a short metal catheter into the bladder not only allows measurement of the postvoid residual, but it also allows the bladder to be probed for the presence of a bladder stone. If the presence of a stone is suspected, cystoscopy can confirm its presence. Removal of a bladder stone is best performed under anesthesia in an operating room.
Treatment of stress incontinence by placing a synthetic mesh sling (usually from a prepackaged "surgical kit") has a high rate of erosion in obstetric fistula patients, even following repair, and should be avoided [51].
A theoretically attractive alternative in appropriately selected patients is the use of a removable urethral plug (eg, FemSoft) [59]. This is a "high technology" solution to incontinence developed in the industrialized West, but directly applicable to the obstetric fistula patient with a nonfunctioning urethra. The insert keeps the urethra closed; it is removed by the patient every three hours to void, and is then reinserted. The main difficulty with the urethral plug is making it accessible to patients. The only current source for such technology is usually through a specialist fistula center that keeps them in store for patient use. As these devices have not been commercially successful in the developed world, they are increasingly difficult to locate in resource-limited countries.
The treatment of last resort is an ileal conduit or some type of continent urinary diversion. For patients in low-resource settings, any treatment that requires ongoing maintenance, supervision, or the use of catheters, bags, or other appliances may be problematic.
The evaluation and treatment of urinary incontinence are discussed separately. (See "Female urinary incontinence: Evaluation" and "Female urinary incontinence: Treatment".)
Long-term outcomes — There is little known about the long-term outcomes for patients in resource-limited settings who undergo obstetric fistula repair. Postoperative data on fistula repair have generally included only the patient's condition at the time of discharge from hospital, often only a few weeks after surgery. Most patients come from rural areas where communication is poor and access to reliable transportation is difficult. Some patients who are still incontinent after surgery return seeking care, but the long-term outcomes for most patients remain unknown. There is an urgent need for better information on long-term clinical outcomes, including postoperative continence, particularly after subsequent childbirth, future reproductive health, and the ability of these patients to reintegrate into their home communities. Because motherhood is the desired and expected life-goal for many African women and because fistulas often develop in a woman's first pregnancy, there is a real need to understand the likelihood of fertility after previous fistula repair and the outcomes of the pregnancies that occur. Current evidence suggests that former fistula patients have reduced fertility and a high risk for obstetric complications in subsequent pregnancies [60,61]. One strategy that has been employed by some centers to encourage women to return for follow-up is to hold an annual "reunion" of fistula patients, with food, song and dance, that is held over several days [62].
A longitudinal study of 481 women discharged with a closed fistula from three repair centers in Guinea followed for a median of 28 months after surgery reported 73 recurrent fistulas in this population for a cumulative incidence of 71 fistulas per 1000 person-years. Of 447 women who were continent at the time of discharge from hospital, there were 24 cases of postrepair urinary incontinence, a cumulative incidence of 23.1 per 1,000 person-years. Of the 305 women who were at-risk for pregnancy after fistula repair, there were 73 total pregnancies (67 pregnant once, 5 pregnant twice, and 1 pregnant three times). There were 11 ongoing pregnancies at follow-up and 6 women had aborted or miscarried. Of the 50 women who delivered during the follow-up period, there were 29 vaginal deliveries (19 home births and 10 in health facilities), resulting in 8 stillbirths, 5 recurrent fistulas, and 1 maternal death. There were also 21 cesarean sections (9 elective and 12 emergencies). The emergency cesarean sections resulted in four stillbirths and two recurrent fistulas [63]. These data clearly demonstrate the deficiencies in health care systems that continue to affect the lives of birth-injured women. The best outcomes after fistula repair result from scheduled cesarean delivery in a health facility, but such services remain beyond the reach of those women most at risk for fistula formation.
Urinary diversion — Cases in which there is no viable bladder tissue remaining and cases in which the entire urethra has been destroyed have a poor prognosis for cure. Controversy exists as to whether or not such patients should be offered some form of urinary diversion, such as an ileal conduit (which, in effect, is an operation to move the fistula from the pelvis to the abdominal wall) or a continent urinary diversion, such as a Mainz II pouch or a ureterosigmoidostomy, which divert the urine into the large intestine [64].
In the case of an ileal conduit, the patient will remain incontinent unless she has access to good stoma care and ostomy supplies in which to collect the urine; if such supplies cannot be provided, the patient may be even worse off and more stigmatized in her culture than if she had never had surgery in the first place. Clinical ethics mandate that such consequences be considered well in advance of surgery, and that adequate provisions to meet these ongoing needs are in place before the diversion takes place. In the case of a ureterosigmoidostomy, it is imperative to insure that the patient has anal continence before the operation is performed. Usually this is done by giving her a large water enema and insuring that she can retain it. If she does not have good anal continence to liquids, then diversions of this kind will result in high volume anal incontinence. The surgeon must also remember that there is an increased risk of colon cancer in patients who undergo a standard ureterosigmoidostomy, and that such patients are also liable to develop electrolyte imbalances that must be monitored and treated.
Continent diversions such as the Mainz II pouch can be done successfully in low-resource settings [65,66], but this requires surgical experience and good postoperative medical and nursing support if it is to be done safely. Not all medical facilities in developing countries will be able to perform such operations skillfully and with acceptable morbidity and mortality. Such operations will also require general, as opposed to spinal, anesthesia, which may not be available in all locations. It is imperative that centers that undertake the performance of such operations simultaneously make the commitment to provide ongoing lifetime care for the needs of these patients and the complications that may develop.
RESOURCES — Resources for clinicians and patients regarding obstetric fistula include:
●The Association for the Rehabilitation and Re-orientation of Women for Development
●United Nations Population Fund: Maternal Health
SUMMARY AND RECOMMENDATIONS
●Definition and clinical significance – Obstetric fistulas are abnormal communications between genital tract and the urinary tract (urogenital fistula) or gastrointestinal tract (most commonly, rectovaginal fistula) caused by obstetric trauma, usually from prolonged obstructed labor. These injuries result in urinary or fecal incontinence. Obstetric fistula is uncommon in countries in which the health care infrastructure is well developed. (See 'Introduction' above.)
●Etiology of obstetric fistula – Obstetric fistulas are caused by an extensive crush injury of pelvic tissues due to obstructed labor during the second stage that is not diagnosed and treated in a timely fashion. With prolonged compression of the tissue between the fetal head and the maternal pelvic bones, tissue ischemia occurs and necrosis develops in the vagina and the connective tissues that separate the vagina from the bladder and rectum. (See 'Obstructed labor' above.)
●Contributing factors – The societal and health care infrastructure factors that contribute to a high prevalence of obstetric fistula include: low social, economic, and political status of women resulting in poor maternal health services; delivery at home with care by untrained birth attendants; limited or no access to emergency obstetric services; infrastructure and economic barriers to travel; lack of or poor quality of secondary and tertiary health care services, and low quality health care in general. (See 'Obstructed labor' above.)
●Evaluation and diagnosis – An obstetric fistula should be suspected in women who present with a complaint of continuous urine loss beginning immediately following childbirth, particularly after a long labor. The amount of time from the onset of symptoms to the presentation of the patient to a health care provider depends upon the patient's ability to access health care. The diagnosis is made by physical examination and a bladder dye test. Access to additional testing (eg, cystoscopy or imaging) is often limited in resource-limited settings. (See 'Evaluation and diagnosis' above.)
●Classification – Classification systems for obstetric fistulas include the World Health Organization system and the Goh system. Complex fistulas are best handled at specialist fistula centers by surgeons who have extensive experience in their management. (See 'Classification' above.)
●Principles of obstetric fistula repair – The three most important principles in obstetric fistula repair are (see 'Procedure' above):
•Broad mobilization of the fistula so that it can be closed without tension at the site of the repair.
•Water-tight closure of urogenital fistulas should be tested intraoperatively before the operation has concluded.
•Adequate bladder emptying in the postoperative period to prevent over-distension of the repair and subsequent breakdown of the suture line.
●Role of diverting procedures – The treatment of last resort is an ileal conduit or other type of urinary diversion. For patients in low-resource settings, any treatment that requires ongoing maintenance, supervision, or the use of catheters, bags, or other appliances may be problematic. (See 'Urinary diversion' above.)
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