General principles of surgical treatment

Timing of repair

The timing of surgical repair is perhaps the single most contentious aspect of fistula management. While shortening the waiting period is of both social and psychological benefit to patients who are always very distressed, one must not trade these issues for compromise to surgical success. The benefit of delay is to allow slough to separate, and inflammatory change to resolve. In both obstetric and radiation fistulas there is considerable sloughing of tissues, and it is imperative that this should have settled before repair is undertaken. In radiation fistulas it may be necessary to wait 12 months or more. In obstetric cases most authorities suggest that a minimum of 3 months should be allowed to elapse, although others have advocated surgery as soon as slough is separated.

Figure 2

Fistula repair instruments

With surgical fistulas the same principles should apply, and although the extent of sloughing is limited, extravasation of urine into the pelvic tissues inevitably sets up some inflammatory response. Although early repair is advocated by several authors, again most would agree that 10-12 weeks postoperatively is the earliest appropriate time for repair.

Pressure from patients to undertake repair at the earliest opportunity is always understandably great, but is never more so than in the case of previous surgical failure. Such pressure must however be resisted, and 8 weeks is the minimum time that should be allowed between attempts at closure.

Route of repair

Many urologists advocate an abdominal approach for all fistula repairs, claiming the possibility of earlier intervention and higher success rates in justification. Others suggest that all fistulas can be successfully closed by the vaginal route. Surgeons involved in fistula management must be capable of both approaches, and have the versatility to modify their techniques to select that most appropriate to the individual case. Where access is good and the vaginal tissues sufficiently mobile, the vaginal route is usually most appropriate. If access is poor and the fistula cannot be brought down, the abdominal approach should be used. Overall, more surgical fistulas are likely to require an abdominal repair than obstetric fistulas, although in the author's series of cases from the UK, and those reviewed from Nigeria, two-thirds of cases were satisfactorily treated by the vaginal route regardless of aetiology.

Instruments

All operators have their own favoured instruments, although those described by Chassar Moir and Lawson are eminently suitable for repair by any route (Figure 2). The following are particularly useful:

• series of fine scalpel blades on the no. 7 handle, especially the curved no. 12 bistoury blade

• Chassar Moir 30° angled-on-flat and 90° curved-on-flat scissors

• cleft palate forceps

• Judd-Allis, Stiles and Duval tissue forceps

• Millin's retractor for use in transvesical procedures, and Currie's retractors for vaginal repairs

Turner Warwick Abdominal Retractor Set

• Skin hooks to put the tissues on tension during dissection

• Turner-Warwick double curved needle holder— particularly useful in areas of awkward access, and has the advantage of allowing needle placement without the operator's hand or the instrument obstructing the view.

Dissection

Great care must be taken over the initial dissection of the fistula, and this stage should probably take as long as the repair itself. The fistula should be circumcised in the most convenient orientation, depending on size and access. All things being equal a longitudinal incision should be made around urethral or midvaginal fistulas; conversely, vault fistulas are better handled by a transverse elliptical incision. The tissue planes are often obliterated by scarring, and dissection close to a fistula should therefore be undertaken with a scalpel or scissors. Sharp dissection is easier with countertraction applied by skin hooks, tissue forceps or retraction sutures. Blunt dissection with small pledgets may be helpful once the planes are established, and provided it takes place away from the fistula edge. Wide mobilization should be performed, so that tension on the repair is minimized. Bleeding is rarely troublesome with vaginal procedures, except occasionally with proximal urethrovaginal fistulas. Diathermy is best avoided, and pressure or underrunning sutures are preferred.

Suture materials

Although a range of suture materials have been advocated over the years, and different opinions still exist, the author's view is that absorbable sutures should be used throughout all urinary fistula repair procedures. Polyglactin (Vicryl, Ethicon, Edinburgh, UK) 2-0 suture on a 25 mm heavy tapercut needle is preferred for both the bladder and vagina, and polydioxanone (PDS, Ethicon, Edinburgh, UK) 4-0 on a 13 mm round-bodied needle is used for the ureter; 3-0 sutures on a 30 mm round-bodied needle are used for bowel surgery, polydioxanone for the small bowel, and either polydioxanone or braided polyamide (Nurolon, Ethicon, Edinburgh, UK) for large bowel reanastomosis.

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