The most commonly quoted population-based estimates of the number of women with obstetrical fistulas is 2 million worldwide. Annual incidence in Africa is estimated to be 50,000 to 100,000 cases. The estimates do not reflect the true number of obstetric fistulas due to the difficulties in obtaining information about these affected women. Several factors contribute to the difficulties, such as isolated and rural settings, religious and cultural barriers, poor infrastructure within countries, and the inability to obtain proper medical care. Most estimates come from fistula centers and hospitals. The largest number of obstetric fistulas occur in sub-Saharan Africa, however, they are encountered throughout the world. Number of fistulas related to sexual violence is estimated at 1 to 3% of all fistulas in certain parts of Africa. It is our experience that there is an under-reported number of fistulas related to poor surgical technique during cesarean section. To quote Wall, women affected with obstetric fistulas are the most dispossessed, outcast, powerless group of women in the world. Proper treatment of these women has received attention from international organizations. International research trials are underway, however, it has become clear that treatment is not standardized. Therefore, comparing outcomes from different centers is difficult at best. This is due in large part to the lack of an internationally accepted fistula classification system. What is not well known is that attempts to classify fistulas dates back to Sims' pioneering work in the 1850s. From that time, nearly 20 fistula classification systems have been proposed. None of the pre-existing classification systems had associated outcomes data. Recently, Goh in 2008 and Waldick in 2009 published outcomes data for their classifications. These two systems will serve as the basis of this video on classifying fistulas. When examining the key components of fistula staging, there are several components that appear to be most important. These include the location of the fistula, the size of the fistula, the extent of scarring, attachment to the pelvic sidewall which is considered a circumferential fistula, whether there is involvement of the closing mechanism, and whether this is a recurrent fistula. The location of the fistula may be along the entire vagina extending into the pelvis. The Goh classification measures the location of the distal edge of the fistula from the external urethral meatus. The urethra may be involved either partially or in its entirety. The fistula may involve the bladder neck and therefore may involve the continence mechanism. Many fistulas involve the mid-vagina, particularly simple fistulas. A fistula high in the vagina may involve the cervix and is referred to as a juxtacervical fistula. Naturally, some fistulas may involve the uterus. It is not uncommon in Africa for the uterovaginal or cervicalvaginal fistula to be associated with a prior cesarean delivery. Some feel that these fistulas are best repaired through an abdominal approach, but more importantly, it is a call for improved surgical training in performing cesarean sections in rural settings. The next component to consider is the size of the fistula. There is no clear definition of how to quantitate size. Both Goh and Waldeck consider the size of the fistula, however Goh describes the size of the fistula interclassification system. The fistula may be small, perhaps less than 1.5 cm, moderate in size, perhaps 1.5 to 2.5 cm, large in size, perhaps 2.5 to 3.5 cm, or extensive, greater than 3.5 cm. Some fistulas measure greater than 10 cm. Scarring is a very difficult component to describe. According to Goh, scarring is described as none or mild, or moderate to severe. Perhaps one of the more difficult fistulas to repair is a circumferential fistula. When a fistula involves the structures adjacent to the bladder, such as the levator muscles, it is described as circumferential. Often the pubic bone is palpable and there is detachment of the bladder from the bladder neck and urethra. Although circumferential damage to the bladder and surrounding structures is considered, other common injuries related to obstetrical fistulas, such as foot drop, stroke, saddle anesthesia, or skin ulcers, are not part of current classifications. A very significant postoperative problem after fistula repair is incontinence. This may result from a small, contracted bladder after fistula repair, but more often it reflects involvement with the continence mechanism. Fistulas that affect the urethra directly, or the bladder neck, are considered to involve the continence mechanism. The Waldick classification, but not the Goh system, types fistulas in their relationship to the closing mechanism. An alternative scoring system by Aerosmith scores fistulas in relation to urethral involvement as intact, partially damaged, or completely destroyed. Even in expert hands, fistula recurrence can occur. Trained surgeons have a much better chance at closing a fistula on the first attempt. A prognostic classification system could prove useful in triaging certain fistulas to fistula centers to be operated on by expert fistula surgeons. As mentioned earlier, the two most commonly used classification systems at present are the Waldick and Goh systems. However, comparing the two classifications is difficult. Outcomes data from Goh published in 2008 and Waldick presented at the WHO in 2009 both show that between 95 and 98 percent of fistulas can be closed successfully. Incontinence however is a major problem after closure of fistulas involving the urethra or bladder neck, those that are larger in size, and those that are circumferential. Let's look at classifying selected cases of vesicovaginal fistulas. Simple fistulas located away from the continence mechanism, usually in the mid-vagina, have been described by nearly all who have proposed a classification system. Waldick classifies a simple fistula as type 1, which is equivalent to a Goh type 1 as well. The small size, less than 1.5 centimeters, and the lack of scarring would classify this fistula as a Goh type 1A1. However, with Goh it is unclear what the success rate is. She reports the fistula closure rates for type 1 fistulas at 94 percent. However, an overall incontinence rate of 7 percent is noted when you consider size and scarring. Waldick reports however less than 1 percent incontinence for type 1 fistulas. The fistula shown here involves the bladder neck, and therefore is considered to involve the continence mechanism according to Waldick. According to Waldick, this particular fistula would be classified as a type 2AA, indicating subtotal urethral involvement and not circumferential. Goh on the other hand does not address the continence mechanism, therefore this small fistula with mild scarring would be classified as a Goh type 2B1. These fistulas shown here are similar in location to the previous one. They definitely involve the continence mechanism as it is described and may be circumferential. Repair of this type of defect would require end-to-end anastomosis of the detached bladder to the urethra. This fistula would be classified as a Waldick type 2AB and a Goh type 2B3. The fistula shown here clearly involves significant tissue loss at the urethra but not the bladder. The fistula is described as a Waldick type 2BA indicating involvement of the closing mechanism, but it is not likely circumferential. Goh would describe this fistula as a type 3 or possibly 4 depending on its distance from the external urethral meatus. This particular fistula appears to be a type 4B2. One can see the dilemma we face in using the current staging systems. This fistula is large in size. After dissection repair of the fistula, extensive tissue loss of the bladder and surrounding tissues such as the levator muscles, pupal cervical fascia, detrusor tissue, and urethral tissue will be found. This particular fistula would be a Waldick type 2BB or a Goh type 3 or 4B2. How to classify a patient with multiple fistulas is difficult. Waldick would likely consider this a type 3 fistula indicating ureteral involvement or an exceptional fistula. Goh would classify this by location and size but also as a subtype 3 also indicating special circumstances. Understanding fistula staging and developing an internationally accepted classification system is critical. Currently there are several shortcomings using the available classifications. Further research and modifications will ultimately lead to a prognostic classification system.

obstetric fistulas

women's health

global incidence

underreporting

classification systems