Obstetric fistula (OF), although virtually eradicated from the developed world, has a number of unique features that make this topic worthy of the attention of practitioners of pelvic surgery anywhere. A discussion of the steps of repair of OF is useful to all pelvic surgeons because of the relative difficulty of repair of OF compared with other types of vesicovaginal fistula (VVF). The etiology of OF is wide-field ischemia.¹ OF injuries tend to be much larger, with more tenuous vascular supply, and located in physiologically more important anatomic areas when compared with fistulae seen in wealthy countries.² Therefore, if one can appreciate the basic principles of OF repair, all will apply to the much simpler problem of postoperative VVF as seen in the West. The techniques of OF repair also are well employed in the challenging area of postirradiation fistulae, which share some features with OF. Figures 36-1 and 36-2 demonstrate longitudinal and vaginal views of large circumferential VVFs that demonstrate some of the complexity of these types of fistula.

Generalized material on the generic approach to OF has been published in symposia³ and surgical manuals.⁴

Preparation/Timing

By tradition, many surgeons impose a mandatory waiting period between injury and attempted repair. However, these beliefs are not supported with randomized, prospective data. Subjectively, most practitioners of OF repair would base a decision of timing of surgery on the condition of the patient and the appearance of the tissues at clinical examination. As would be the case with any major pelvic reconstruction, the patient should be assessed for nutritional status and general medical fitness for surgery. It is quite common in OF to see patients present for care in an advanced state of malnutrition. These patients can require long periods of rehabilitation prior to the safe performance of fistula repair. Since OF results most commonly from regional ischemia, it is also not uncommon to encounter patients for whom the process of sloughing of necrotic tissue is not yet complete. In these cases, fistula repair should not be attempted until necrotic tissue is not present.

Approach

Ideally, a fistula surgeon should be comfortable with either the vaginal or the abdominal approaches. There are specific indications where either could be strongly preferred. However, as a routine choice, it is clear that the vaginal approach has significant advantages over the abdominal one. Many fistulae either are located at the bladder neck or involve the urethra. In these cases, an abdominal approach simply will not allow exposure of the defect. If the vagina has been significantly reduced in caliber through ischemia, a vaginal flap can restore normal sexual function to the patient. There is little doubt that a vaginal repair is less morbid, especially in the low-resource settings of hospitals in the developing world, than opening the abdomen.

There are specific indications for abdominal repair. Ureterovaginal fistulae require abdominal reimplantation unless the orifice is lying just outside the bladder and can be successfully mobilized enough to allow reimplantation from below. Some very high fistulae, especially in cases with a closed vagina, can be technically easier to approach from above. However, it is quite possible to repair even uterovesical fistula from a vaginal approach. One fairly common scenario is women with OF and a large ventral hernia from a disastrous cesarean section. In these cases, an abdominal approach can address both issues via a single incision.

All of this being said, the vaginal approach is the gold standard for OF repair, and will be presented here exclusively. The times when abdominal repair is mandated are few.

Positioning and Exposure

If OF repair can be done routinely by a vaginal approach, it is not always easy to do so, and extra care must be taken to allow maximum exposure. The challenge is to be able to see the entire anterior vaginal wall. The result is a modification of the lithotomy position. Seen for the first time, the position seems extreme (Figure 36-3). Taking care to pad the legs adequately, the patient is positioned with her buttocks off the end of the operating table. This position appears inherently unhealthy, as the hips extend in an exaggerated fashion at the lower lumbar spine. Then the table is placed in a 30° to 45° head-down/Trendelenburg position. As the head of the table is lowered to this extent, the exaggerated extension of the lower spine resolves and the buttocks rest on the padding at the end of the table. In some patients, there can be problems with the patient sliding toward the lowered end of the table as the case progresses. If they are available, shoulder supports placed on the side rails of the operating table can prevent this distracting issue.

Since fistula repair is most commonly performed under spinal anesthesia, new fistula surgeons often react with dismay to this patient position for fear of inadvertently inducing a high spinal. However, allowing adequate time between placement of the spinal and positioning of the patient minimizes this risk.

After draping the patient, there are a few remaining maneuvers that can be employed to improve exposure. Whenever possible, an Auvard vaginal speculum is placed. Not infrequently, the degree of loss of vaginal length can preclude the use of an Auvard, and in these cases, the surgeon is left with the awkward prospect of having an assistant place a smaller Sims speculum and pull downward on it throughout the repair. In most cases, labial sutures can help with lateral exposure. Most any suture material can be used for labial retraction provided it is 3-0 or larger in caliber. Sutures are ideally placed between the skin of the perineum and the labia minora at the 10- and 2-o’clock positions. A metal female urethral catheter (such as the Walther) can be placed in the urethra to distract the anterior vagina down into view (Figure 36-4).

One point of variance in technique involves the use of incisions for exposure. For some OF surgeons, deep lateral incisions to release scarring are a routine part of nearly every repair. There are certainly OF cases where the degree of scarring is so severe that there is no other option for exposure of the fistula but to make long, deep cuts on either lateral vaginal wall. The long-term effects of the use of incisions for exposure in fistula repair have not been studied.

Very small and high fistulas can present special difficulty in exposure. In these cases a pediatric Foley catheter (8F) or a Fogarty vascular catheter can be inserted from the vagina into the bladder via the fistula. Then the catheter balloon is inflated and the catheter can be used as a retractor to pull the fistula into view during the initial dissection. It is also possible to place stay sutures in the vaginal edges of the fistula to allow the defect to be exposed.

In larger OF lesions, the bladder will often prolapse through the fistula defect and out into the vagina (Figure 36-5). This differs from a cystocele in that it is the inner mucosal rather than the outer surface of the bladder that presents itself to the surgeon. This may be a positive prognostic sign, since prolapse of the bladder infers that there is plenty of bladder tissue that has survived the ischemic injury. But prolapse of the bladder through the fistula makes it very difficult to see the edges of the fistula. This situation is simply remedied by placing one or two 4 × 4 surgical sponges into the bladder via the fistula. Obviously, the sponges must be removed once closure of the fistula begins.