There is currently no unified classification scheme for accurately describing vesico-vaginal fistulas, thereby limiting communication between surgeons and the ability to compare research. Frajzyngier et al examined prognostic values of classification systems and found them to be “poor to fair.” Goh’s classification is based on the location of the fistula in relation to the external urethral orifice, size of the fistula, and extent of scarring or other subjective factors that might predict success. Waaldijk’s classification is also based on the urethral closing mechanism and size with increasing complexity from type I to III, however, preoperative classification does not significantly predict outcome of surgery. Many other factors related to surgical failure/success have not been explored and surgeons currently do not universally use the same classifications. The objective of this manuscript is to determine which factors are the most important to include in a future obstetric fistula classification scheme.

Members of the International Society of Obstetric Fistula Surgeons were solicited to participate in a non-validated questionnaire. First, surgeons reported how many fistula surgeries they have performed. Experts performed over 200 fistula repairs. Then, surgeons determined whether several factors were important for a future comprehensive obstetric fistula classification scheme. Additionally, participants rated these factors on a scale of 0 to 10.

Eighteen surgeons completed the questionnaire. Surgeons were asked which factors they felt were essential to include in a comprehensive obstetric fistula classification system. Additionally, the surgeons ranked these factors on a Likert scale of zero to ten, with zero of minor importance and 10 of utmost importance. The results are displayed in table 2. The most critical factors that surgeons found necessary to include in an updated fistula classification system are the bladder size (88.9%, n=16, 8.53), degree of fibrosis of the vagina (83.3%, n=15, 8.12), degree of urethral damage (88.9%, n=16, 9.34), location of the fistula (100%, n=18, 9.22), urethral length (94.4%, n=17, 9.06), and whether the fistula is circumferential or not (94.4%, n=17, 9.18). The least important factors were how long the patient had had a fistula (11.1%, n=2, 2.28) and intraoperative complications (22.2%, n=4, 4.59). Factors of intermediate importance included the degree of damage to the vagina (55.5%, n=10, 7.11), fistula size (7.33), history of previous fistula repair (77.7%, n=14, 8), the skill of the operating surgeon (55.5%, n=10, 6.29), vaginal scarring (61.1%, n=11, 7.71), whether the urethra was blocked or not (44.4%, n=8, 6.34).

Upon survey of experienced and expert fistula surgeons, the following factors were deemed as most important for a classification scheme: bladder size, degree of fibrosis of the vagina, degree of urethral damage, location of the fistula, urethral length, and whether the fistula is circumferential or not. Three of the most commonly used classification schemes by Goh, Waaldjik, and WHO only capture some important factors determined by the surgeons. The Goh classification includes essential factors such as bladder capacity seemingly as a function of bladder size, fibrosis of the vagina, and the circumferential defect. It does not include the degree of urethral damage and urethral length. The Goh classification notably allows for a more precise characterization of the location of the fistula than does Waaldjik and WHO; however, its characterization of location is a function of the distance from the external urinary meatus and does not account for whether the fistula is lateral to the sagittal plane of the urethral. While both the Waaldjik and WHO classification systems include the presence of a circumferential defect, they do not characterize bladder size, the fistula's location, and the urethral length. The WHO system utilizes "degree of tissue loss" and "involvement of the urethra/continence mechanism" as proxies to determine the damage to the urethra, but it does not provide enough specific information. Similarly, Waaldjik allows for the classification based on subtotal or total urethra involvement. 

Surgeons determined that the following factors were of lesser importance: how long the patient had had a fistula, intraoperative complications, degree of damage to the vagina, fistula size, history of previous fistula repair, the skill of the operating surgeon, vaginal scarring, and whether the urethra was blocked or not. All three classification schemes include fistula size. The Goh Classification scheme includes prior fistula repair. Any of the three classifications did not include the remaining factors. Fistula size was deemed of intermediate importance by the surgeons receiving a mean score of 7.33. While surgeons found other factors important to include, this data may indicate that a smaller proportion of the classification scheme should be attributed to characterizing the size, and more emphasis should be placed on surgeon-reported critical factors such as bladder size, vaginal fibrosis, urethral damage, location, urethral length, and circumferential defect.

An updated obstetric fistula classification scheme should include bladder size, vaginal fibrosis, urethral damage, location of the fistula, urethral length, and circumferential or non-circumferential defect. This system should expand upon Goh's classification of the location of the fistula to include characterization of the laterality of the fistula and include factors such as degree of urethral damage, urethra length, and bladder size. Additionally, this classification scheme should be tested for homology amongst surgeons to ensure that surgeons are consistently categorizing fistulas correctly according to the newly constructed system. A universally accepted and utilized classification system with a greater degree of applicability to the variability of obstetric fistula presentations would allow for comparative research in terms of the complexity of repair, required skill of the operating surgeon, best surgical approach, and expected outcomes. This classification system would provide surgeons with the tools to better treat obstetric fistula, thus yielding improved patient outcomes.