One of the most devastating consequences of obstructed labor is the vesico-vaginal fistula. To appreciate the nature of this problem in the developing world, it is instructive to compare vesico-vaginal fistula rates in the developed world with those in the developing world. Goodwin and Scardino collected information about vesico-vaginal fistulas that were treated at University of California at Los Angeles (UCLA) and its affiliated hospitals. They found only 43 cases of vesico-vaginal fistulas over 20 years ( Table 2 ). Lawson found 166 cases of vesico-vaginal fistulas over an 18-year period in Newcastle-upon-Tyne, United Kingdom. Compare these with the report of 377 cases in Ibadan, Nigeria, over a 16-year period ( Table 3 ).
Similar to the incidence of fistulas, the etiologies of fistulas are much different in the developed world as compared with the developing world. In the developing world, vesico-vaginal fistulas are overwhelmingly a result of obstructed labor. In the developed world, they are more likely to be due to a surgical injury, or less likely, radiation. Only 2 of the 43 cases of vesico-vaginal fistulas in the UCLA review were due to obstetric causes; the remainder resulted from surgical complications or radiation therapy ( Table 2 ). In the UK study, 21 of the 166 fistulas were due to obstetric causes; only 4 of these 21 were a result of obstructed labor, and all 4 of the obstructed labor cases were referred from developing countries. The other obstetric fistulas resulted from operative deliveries or cesarean sections. In Nigeria, almost all of the fistulas (369 out of a total of 377) were due to obstetric complications, and only 7 resulted from surgical complications ( Table 3 ).
In the developing world, the true incidence of vesico-vaginal fistulas is unknown, as many patients with this condition suffer in silence and isolation. Some estimates place the worldwide prevalence as high as 2 million women worldwide. As previously mentioned, the fistula hospital in Ethiopia treats approximately 700 new patients per year. In his review from West Africa, Elkins noted a fistula rate of 1-3 per 1000 deliveries; and in a review of 22,774 deliveries from Nigeria, Harrison estimated the vesico-vaginal fistula rate to be 3.5 per 1000 births. In some rural areas of Africa, the fistula rate may approach 5-10 per 1000 deliveries -- which is close to the maternal mortality rate in Africa.
Vesico-vaginal fistulas result from tissue ischemia and subsequent necrosis during labor. During normal labor, the bladder is displaced upwards in the abdomen so the anterior vaginal wall, bladder base, and urethra are compressed between the fetal head and the posterior pubis (Figure 4). If this occurs for a short period of time, there is no tissue damage. If, however, there is prolonged obstructed labor, the intervening soft tissues become ischemic. This area undergoes pressure necrosis, and within 3-10 days postpartum, the tissues slough off. Typically, the length of pressure without relief is more important than the magnitude of pressure. Given that the average length of labor for patients at the fistula hospital in Addis Ababa is 3.9 days, with some labors lasting as long as 6 days, it is not surprising that fistulas result. It is important to recognize that the pathophysiology of the obstetric fistula is completely different from that of the surgical fistula. The vesico-vaginal fistulas that result from operative complications are most often focal injuries -- for example, injury from improper clamp placement at the time of hysterectomy. Consequently, the surgical fistula is a small injury surrounded by healthy tissue. By contrast, the obstetric fistula is a field injury with a large defect surrounded by damaged, ischemic tissue.
The fetal head in the pelvis during labor. From Zacharin RF. Obstetric Fistula. New York, NY: Springer-Verlag; 1988. Reprinted with permission from Springer-Verlag.
The typical fistula patient is young, primiparous, separated from her partner, and has had little or no education. Among patients at the fistula hospital in Ethiopia, the average age at which they developed a fistula is 18.9. A study from Nigeria found that more than 30% of the fistula patients were younger than 16 years of age. These women usually have had just 1 pregnancy. In Ethiopia, more than 60% of the fistulas seen are a result of a woman's first delivery. As mentioned previously, these women are usually isolated and have limited support. Another study from Nigeria found that 80% of fistula patients had been abandoned and 60% were divorced or separated. An overwhelming number of these women are uneducated. One report from Nigeria found that 99.4% of the fistula patients were illiterate. In another report of 1443 patients who underwent surgery for vesico-vaginal fistulas, only 3 had received any conventional education. As a result, these women maintain a subordinate position in society. They are often excluded from decision making, even decision making about their own health. As noted by Zacharin, "in an unequal world, these women are the most unequal among the unequal."
Although ischemic damage is the principal cause of obstetric fistula, many factors contribute to its widespread prevalence in the developing world. These important contributing factors explain why this problem persists in the developing world and is essentially obsolete in the developed world. In developing countries, many women have a contracted pelvis, most often a result of malnutrition and increased infection rates in adolescence leading to growth stunting and poor development. This, compounded by the fact that often women marry young and begin childbearing before growth is complete, partially explains the high prevalence of obstetric fistulas in the developing world. In fact, one Nigerian study found that as many as 90% of girls are married before menarche. Genital tract mutilation also contributes to a high fistula rate. In particular, the Gishiri cut -- a cut through the introitus into the anterior vaginal wall against the pubis -- is quite common among the Hausa women in Nigeria. It is used to treat dyspareunia, infertility, prolapse, and, of course, obstructed labor. A report from one Nigerian hospital found that 40% of the fistula patients have experienced a Gishiri cut.
Another factor is the lack of skilled obstetric providers in the developing world. It has been said that the incidence of obstetric fistulas is a direct indicator of quality obstetric care in an area. It is easy to understand that Ethiopia has one of the highest rates of obstetrical fistulas, considering the fact that there are more Ethiopian doctors in New York City than in Ethiopia. As a result, many women rely on traditional healers. They are viewed as more accessible and more familiar. In addition, parturition is regarded as a normal process not requiring medical attention; a hospital is viewed as a place to die, not a place to give birth. Even if women did not want to deliver at home, the physical barriers are so great, and the transportation so limited, that it is nearly impossible for some to deliver within a medical facility. A report from Gambia noted that most women were 20 kilometers from an antenatal clinic and 200 kilometers from emergency obstetric services. In Ethiopia, 82% of the patients traveled more than 700 kilometers to reach the fistula hospital. These women spent an average of 34 hours on a bus and 12 hours on foot to reach the hospital. It is, therefore, quite clear, why Dr. Hamlin emphasizes that vesico-vaginal fistulas result from both obstructed labor and obstructed transport.
Before explaining the management of vesico-vaginal fistulas, it is important to understand their classification. Elkins clearly described the types of obstetric fistula in his 1994 review. These are vesicocervical, juxtacervical, midvaginal vesicovaginal, suburethral vesicovaginal, and urethrovaginal (Figure 5). The remaining discussion of fistula management will focus on the midvaginal vesicovaginal fistula, because a description of the repair of this fistula emphasizes the basic techniques of fistula repair.
There are 5 principal steps involved in closure of the vesico-vaginal fistula. These include mobilization of the bladder from the vaginal wall, identification of the ureters, closure of the bladder wall, placing a graft between the bladder and the vagina, and closing the vaginal skin. The first step in successful closure of the vesico-vaginal fistula is to free the bladder from the vaginal wall. The goal is to allow tension-free bladder closure, for tension significantly increases the risk of failure. Dissection must be sufficient but not excessive, as excessive dissection may disrupt the vascular supply (Figure 6). Most obstetric fistulas are large enough that there is a high likelihood of ureter involvement at or near the fistula edge. Thus, ureter involvement must be presumed in each case until it is disproven, and ureteral orifices should be identified and catheterized. This said, ureteral catheters are not readily available in the developing world, but every attempt should be made to identify the orifices (Figure 7). The bladder is closed using interrupted, absorbable sutures. Ideally, the bladder is closed in a 2-layer approach; however, this is not always possible with very large fistulas. Following closure of the fistula, the patency of the suture line must be tested by injecting methylene blue or sterile milk into the bladder through the catheter (Figure 8).
Mobilization of the bladder. From Zacharin, Obstetric Fistula; 1988. Reprinted with permission from Springer-Verlag. From Zacharin RF. Obstetric Fistula. New York, NY: Springer-Verlag; 1988. Reprinted with permission from Springer-Verlag.
Identification of the ureters. From Zacharin RF. Obstetric Fistula. New York, NY: Springer-Verlag; 1988. Reprinted with permission from Springer-Verlag.
Closure of the bladder wall. From Zacharin RF. Obstetric Fistula. New York, NY: Springer-Verlag; 1988. Reprinted with permission from Springer-Verlag.
The Martius graft was first proposed in 1928 by the German physician, Heinrich Martius. He used the bulbocavernosus muscle inserted between the bladder and vaginal sutures in an attempt to improve the fistula repair. This important technique continues to be used today, and most surgeons recommend that it should be used with all fistulas except the very small and the very large, when it would be inadequate. The benefits of grafting include covering minor defects in the suture line, bringing a fresh blood supply into an area of poor-quality tissues, and keeping the healing of the bladder and vaginal wall apart, which limits the opportunity for communication during the healing process (Figure 9). After placement of a graft, the vaginal mucosa is closed. Some recommend absorbable suture, although others have recommended nylon suture for this portion of the repair (Figure 10). Following repair, the bladder should be completely drained for at least 10 days, and sometimes the catheter must remain in place for up to 3 weeks.
Placement of the Martius graft. From Zacharin RF. Obstetric Fistula. New York, NY: Springer-Verlag; 1988. Reprinted with permission from Springer-Verlag.
Closure of the vaginal wall. From Zacharin RF. Obstetric Fistula. New York, NY: Springer-Verlag; 1988. Reprinted with permission from Springer-Verlag.
The success rate of fistula surgery is quite high. In Elkins' 1994 report of 100 operations in 82 patients, overall, 95% of the patients had successful closures. Urethrovaginal fistulas had the highest cure rate, with 31 of 33 (94%) successfully closed on the first attempt. Midvaginal vesicovaginal fistulas had the lowest primary closure rate (10 of 14, or 71%). Those vesico-vaginal fistulas that were associated with recto-vaginal fistulas or uretero-vaginal fistulas had even lower rates of successful closure, although only 7 patients in the study had combined fistulas (4 of 7 closed, 57%) ( Table 4 ). This study also demonstrated that the success rate declined with increasing attempts at closure. Of patients undergoing their first attempt at closure, 85% had a successful repair, whereas only 33% of those patients undergoing their third attempt had a successful repair ( Table 5 ).
Nonetheless, although many of these women have their fistulas repaired successfully, many continue to suffer other sequelae of obstructed labor. In Elkins' report, 59% of patients had persistent complications of obstructed labor, including gynatresia, amenorrhea, incontinence, and leg weakness. Thus, as Murphy notes, "by far the most satisfactory solution to the problem would be to prevent it." As mentioned, the hope of those at the fistula hospital in Ethiopia is that it will not need to exist in the future. Clearly, education of women is one of the most important interventions needed to reduce the incidence of obstetric fistulas. In addition, women's partners, their relatives, and influential people in the community must also be educated about the dangers of obstructed labor. In Nigeria, it was shown that after women received formal education, the number of women who delivered in hospitals increased from 3866 to 6436. Women who receive antenatal care are more likely to be educated about obstructed labor, and thus, improvements in antenatal care are vital to the prevention of fistulas and other complications of obstructed labor.
Although the ideal situation is to have more health centers and better transportation, many communities have overcome this obstacle by establishing maternity waiting homes where women can live before their delivery. In Nigeria, the perinatal and maternal mortality was compared in areas with and without maternal waiting homes. In the areas without waiting homes, there were 70 perinatal deaths and 7 maternal deaths. In areas with waiting homes, there were 6 perinatal deaths and no maternal deaths. Notably, the number of cases of cephalo-pelvic disproportion was similar in the 2 areas.
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Cite this: Lessons From the Developing World: Obstructed Labor and the Vesico-Vaginal Fistula - Medscape - Aug 15, 2003.