We reviewed literature examining predictors of urinary fistula repair outcomes in developing country settings, including fistula and patient characteristics, and perioperative factors. We searched Medline for articles published between January 1970 and December 2010, excluding articles that were (1) case reports, cases series or contained 20 or fewer subjects; (2) focused on fistula in developed countries; and (3) did not include a statistical analysis of the association between facility or individual-level factors and surgical outcomes. Twenty articles were included; 17 were observational studies. Surgical outcomes included fistula closure, residual incontinence after closure, and any incontinence (dry vs wet). Scarring and urethral involvement were associated with poor prognosis across all outcomes. Results from randomized controlled trials examining prophylactic antibiotic use and repair outcomes were inconclusive. Few observational studies examining perioperative interventions accounted for confounding by fistula severity. We conclude that a unified, standardized evidence-base for informing clinical practice is lacking.
An obstetric fistula, or abnormal opening between the vagina and the bladder or rectum, is a devastating condition. It is caused by prolonged obstructed labor: the fetus’ head compresses soft tissues of the bladder, vagina, and rectum against the woman’s pelvis, cutting off blood supply, causing these tissues to die, and slough away. It can result in urinary or fecal incontinence or both; concomitant conditions may include painful rashes resulting from constant urine leakage, amenorrhea, vaginal stenosis, infertility, bladder stones, and infection. Women having obstetric fistula may be abandoned by their husbands and ostracized by their communities. Although global prevalence is unknown, the self-reported lifetime prevalence of fistula symptoms reported in Demographic and Health Surveys has ranged from 0.4% in Nigeria to 4.7% in Malawi.
Less frequently, genitourinary and rectovaginal fistulas may result from sexual violence, malignant disease, radiation therapy, or surgical injury (most often to the bladder during hysterectomy or cesarean section [C-section]). Surgical injury, malignant disease, and radiation therapy are the predominant cause of the condition in industrialized countries; indeed, obstetric fistula rarely occurs in settings where competent emergency obstetric care is readily accessible. Fistulas resulting from surgical injury are characterized by discrete wounding of otherwise normal tissue, whereas both obstructed labor and radiation may lead to extensive ischemia and scarring.
There are 2 broad research priorities in the vaginal fistula (hereafter referred to as “fistula”) repair field. One is to evaluate which operative techniques and methods of perioperative patient management are most effective and efficient for fistula closure and prevention of residual incontinence after successful closure. Many fistula surgeons have developed their own methods through experience and thus a wide variety of procedures and methods are commonly used. The other need is for evidence to support the development of a standardized evidence-based system for classifying fistula prognosis, and at a minimum, a system prognostic for fistula closure. Currently at least 25 systems are used and parameters measured by these classification systems vary greatly. To date, the prognostic value of only 2 systems has been tested; these analyses were conducted after the adoption of these systems, rather than to create them. To develop a prognostic system, it is necessary to determine which patient and fistula characteristics independently predict outcomes, and to identify the minimal parameters required for accurate prognosis, because the simpler a classification system, the more likely it is to be used. A prognostic classification system would not only facilitate the evaluation of surgical success rates across facilities, but also the effectiveness of interventions independent of confounding by patient or fistula characteristics; it would also facilitate the comparative analysis of studies that examine treatment outcomes.
In light of the previously described priorities, and increased research on obstetric fistula in recent years, we aimed to systematically review and synthesize the evidence regarding factors that may influence fistula repair outcomes in developing countries, including fistula and patient characteristics, as well as perioperative factors (eg, perioperative procedures and other aspects of service delivery). Based on these findings, our goal was to identify future research priorities to fill existing knowledge gaps.
Materials and Methods
We conducted a systematic review of the Medline database to identify relevant publications by searching for articles published from 1970-2010, using the following topic headings: “obstetric fistula,” “vaginal fistula,” “urinary bladder fistula,” “vesicovaginal fistula” and “fistula”; this yielded 6589 articles. The search was refined by excluding the MeSH headings clearly unrelated to the female genital fistula of interest, namely “infant, newborn,” “male,” “kidney transplantation,” “adenocarcinoma,” “radiotherapy,” “penis,” “animals,” “prostatectomy,” “Crohn’s disease” “child, preschool” “radiation injuries,” and “kidney diseases.” This yielded 2437 articles. We reviewed titles of these articles excluding those clearly not meeting our eligibility criteria. This resulted in 526 articles whose abstracts were reviewed to determine eligibility.
Articles included in the final analysis met the following criteria: peer reviewed; original research; focused on predictors of fistula repair outcomes; published after 1970; and written in French or English. Articles were excluded if they were case reports, cases series, or contained 20 or fewer subjects; focused on fistula in developed countries (because most of these are secondary to surgery or malignancy, and results from such studies may not be generalizable to developing countries where obstetric fistula predominates); and did not statistically analyze associations between predictors and surgical outcomes. Review of references of published papers yielded 1 additional article that met the inclusion criteria. One additional article was identified via an internet search engine (Google) ( Figure ).
Twenty articles examining predictors of fistula surgery outcomes were identified ( Table 1 ), and data on sample characteristics, study design, exposures, outcomes, and effect estimates were abstracted by 1 author. Fourteen studies reported results of retrospective record reviews, 3 were prospective studies, and 3 were randomized controlled trials (RCTs). A minority of the observational studies accounted for potential confounding with multivariate analysis. Sample sizes ranged from 34 to 1045; half had samples over 100 and one-quarter had samples under 50. Studies examined a variety of predictors ( Table 2 ): 8 examined patient or fistula characteristics, 6 examined perioperative factors, and 5 examined both. Three studies were restricted to women undergoing primary repairs.
| Author, y | Study design | Population | Sample size | Outcome definition | Exposures of interest | Analytic approach a |
|---|---|---|---|---|---|---|
| Kirschner et al | Retrospective record review | Patients with vesicovaginal fistula; where unit of analysis was individual patient, analyses were restricted to women undergoing first repair | 1084 records from 926 patients | Continence (dry vs wet), assessed at time of discharge | Patient characteristics (age at surgery, education, parity, number of living children, literacy, language group, and marital status), clinical data (cause of fistula and number of previous surgeries), and surgical data (type/location of fistula, degree of fibrosis, surgical approach, and procedures performed) | Independent sample t tests and χ 2 tests GEE bivariate and multivariate regression. Multivariate models adjusted for confounding by days in labor, number of living children, marital status, months with fistula, and place of delivery |
| Muleta et al | RCT | Patients with obstetric fistula undergoing first repair | 722 patients | Fistula closure, assessed after catheter removal and before discharge | Single-dose gentamycin vs extended antibiotic use. Extended antibiotic use included any 1 or combination of amoxicillin (500 mg IV and oral 6 hourly), chloramphenicol (500 mg IV and oral 6 hourly), or cotrimexazole (800 mg orally every 12 hours) for 7 d. | χ 2 , risk difference |
| Nardos et al | Retrospective record review | Patients with obstetric vesicovaginal fistula undergoing first repairs via vaginal route | 1045 patients | Fistula closure, b assessed after catheter removal and before discharge | Extent of urethral destruction, circumferential damage, extent of scarring, residual bladder size, repair technique (single vs double layer closure) | Logistic bivariate and multivariate regression |
| Lewis et al | Retrospective record review | Patients with genitourinary fistula | 505 records from 435 patients | Continence (dry vs wet), assessed via subjective appraisal after catheter removal and before discharge | Patient demographics (age), obstetric history (index pregnancy), and fistula parameters (number of prior repairs, fistula type, site and size, degree of fibrosis, and urethral status | χ 2 and Wilcoxon rank sum test; bivariate analyses stratified by primary vs subsequent repair GEE multivariate regression |
| Olusegun et al | Retrospective record review | Patients with vesicovaginal fistula | 37 patients | Continence (dry vs wet) at discharge (personal communication, A.K. Olusegun, July 2011) | Duration of fistula before repair | χ 2 |
| Safan et al | RCT | Patients with complicated fistula (defined as recurrence, local moderate to severe fibrosis, fistula location involving the bladder neck, and/or size of the fistula >1.5 cm in largest diameter) | 38 patients | Continence (dry vs wet), assessed at 3 mo follow-up | Primary exposures were fibrin glue vs martius flap as interpositioning layer. Also examined parity, patient age, attempts of previous repairs, fistula size, and fistula location | χ 2 or Fisher exact tests |
| Goh et al | Prospective | Patients with genitourinary fistula (women with rectovaginal fistula only or no bladder tissue excluded) | 987 patients | Fistula closure and residual urinary incontinence after successful closure, assessed after catheter removal and prior to discharge | Components of Goh’s classification system: Fistula type (characterized by distance of fistula from external urinary meatus), size, “special considerations” (extent of fibrosis and vaginal length, and special circumstances such as previous repair, ureteric involvement, etc) | χ 2 test and logistic multivariate regression (residual incontinence only) |
| Morhason-Bello et al | Retrospective record review | Patients with midvaginal fistulas with no fibrosis, evidence of infection, urethral or bladder neck involvement and >1 previous repair attempt | 71 patients | Continence 3 mo after surgery | Abdominal vs vaginal route of repair | Fisher exact test |
| Nardos et al | Retrospective record review | Patients with obstetric fistula (women with rectovaginal fistula only excluded) | 212 patients | Fistula closure and residual incontinence, assessed after catheter removal and before discharge (differences at 6-mo follow-up not tested) | 3 duration of catheterization groups: 10 d (group 1), 12 d (group 2), and 14 d (group 3) | Unspecified (χ 2 assumed); bivariate analyses stratified by components of Goh classification system |
| Raassen et al | Prospective | Patients with obstetric fistula undergoing first-time repair | 581 patients | Fistula closure assessed via dye test prior to catheter removal (14-21 d after surgery) and residual urinary incontinence after successful closure assessed after catheter removal before discharge | Patient characteristics (age and duration of leakage) and components of Waaldijk classification system (type of fistula characterized by extent of involvement of closing mechanism and presence of circumferential defect, exceptional fistulas and size) | χ 2 and Fisher exact tests and logistic multivariate regression (closure only) |
| Holme et al | Retrospective record review | Patients with obstetric fistula | 259 patients | Closure, not closed, residual incontinence; time period unspecified | Scarring | Spearman correlation |
| Browning | Retrospective record review | Patients with obstetric fistula (women with rectovaginal fistula only excluded) | 413 repairs | Fistula closure assessed via dye test prior to catheter removal (14-21 d after surgery) and residual urinary incontinence after successful closure assessed after catheter removal before discharge | Martius graft | Fisher exact or χ 2 tests with continuity correction; bivariate analyses stratified by components of Goh classification system and other fistula characteristics |
| Browning | Retrospective record review | Patients with obstetric fistula (women with breakdown of repair, lack of bladder tissue and rectovaginal fistula only excluded) | 481 women | Residual incontinence after fistula closure, assessed after catheter removal and before discharge | Urethral involvement, repeat surgery, size of fistula, size of bladder, location of ureter, scarring, flap required, presence of rvf, number of vvf, age, parity, duration labor, time since delivery, diameter of fistula, delivery method and outcome of delivery | t test, Mann-Whitney U test, and logistic multivariate regression |
| Chigbu et al | Retrospective record review | Patients with juxtacervical vesicovaginal fistula | 78 women | Fistula closure at either 6 wk or 3 mo (personal communication, H. Onah, July 2011) | Route of repair (vaginal vs abdominal) | t tests and χ 2 tests |
| Melah et al | Retrospective record review | Patients with vesicovaginal fistula | 80 women | Fistula closure and residual incontinence after closure; time period of assessment unspecified | Early (<3 mo) vs late (after 3 mo) closure | χ 2 test |
| Kriplani et al | Retrospective record review | Patients with genital fistula (radiation fistulas excluded) | 34 women | Continence after catheter removal | Age, parity, duration of fistula, route of repair, etiology | Levene’s test of equality of variances and χ 2 test with Yates correction |
| Murray et al | Retrospective record review | Patients with obstetric fistula | 55 women | Residual incontinence after fistula closure, assessed between 4 wk and 3 mo after repair | Mean fistula diameter | Wilcoxon signed rank sum test |
| Rangnekar et al | Retrospective record review | Patients with urinary-vaginal fistulas (excluded fistulas situated high on the posterior wall of the bladder and fistulas <1.5 cm in size) | 46 women | Fistula closure assessed via dye test before catheter removal and residual incontinence after closure, assessed with urodynamic test 3 wk postoperatively | Martius flap repair | Fisher exact test |
| Tomlinson and Thornton | RCT | Patients with obstetric vesicovaginal fistula | 79 women | Fistula closure and continued incontinence (positive pad test) at hospital discharge | 500 mg ampicillin | Mann-Whitney (nonparametric tests) |
| Bland and Gelfand | Prospective | Patients with vesicovaginal fistula | 60 women | Closed fistula 6 wk after repair | Urinary bilharziasis defined by presence of ova on bladder biosopsy or urine examination or rectal snip | χ 2 test with Yates correction |
a Only the analytic approach for the outcome of interest is reported;
b Unless otherwise specified, fistula closure was assessed using dye test if the patient reported urine leakage.
| Predictor | Closure | Residual incontinence | Any incontinence | |||
|---|---|---|---|---|---|---|
| Influence b | No influence/inconclusive c | Influence | No influence/inconclusive | Influence | No influence/inconclusive | |
| Patient characteristics | ||||||
| S haematobium | ||||||
| Age at fistula repair | ||||||
| Age at fistula occurrence | ||||||
| Duration of fistula | ||||||
| Parity | ||||||
| Number living children | ||||||
| Mode of delivery | ||||||
| Days in labor | ||||||
| Education | ||||||
| Literacy | ||||||
| Place of delivery | ||||||
| Fistula characteristics | ||||||
| Etiology | ||||||
| Number of fistulas | ||||||
| Fistula size | ||||||
| Scarring | d | d , | ||||
| Bladder size | ||||||
| Bladder neck/circumferential fistula | ||||||
| Extent of urethral involvement/circumferential fistula | ||||||
| Ureteric involvement | ||||||
| Other fistula location (“low,” juxtacervical) | ||||||
| Combined VVF/RVF | ||||||
| Previous repair | ||||||
| Perioperative factors | ||||||
| Abdominal vs vaginal surgical route | ||||||
| Catheter for 10, 12, 14 d | ||||||
| Single (vs double) layer closure | ||||||
| Relaxing incision | ||||||
| Martius fibrofatty flap/graft | ||||||
| Martius graft (vs fibrin glue) | ||||||
| Antibiotic prophylaxis | ||||||
| Single dose (vs extended antibiotics) | ||||||
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