[Diagnostic nomograms for the treatment of urogenital fistula]

Studies on non-obstetric urogenital fistula provide limited information on predictive factors. The aim of our study was to specify and to analyze the predictors for long-term anatomical and functional results in women with non-obstetric urogenital fistula.

A cross-section study of surgical repair for non-obstetric urogenital fistula repairs was carried out. From 2012 to 2018, a total of 446 patients with urogenital fistulas were treated in two tertiary centers. Patients with vesicovaginal and urethrovaginal fistulas with at least 12 months of follow-up were identified and contacted by phone and/or examined in the clinic. Anatomical outcome was assessed by resolution of symptoms and/or results of clinical examination. Urinary distress inventory (UDI-6) was used for the measurement of functional outcomes. The nomogram is based on a multiple regression equation, the solution of which is performed using a computer. The nomogram is presented as a set of scales, each of which corresponds to a certain variable. The baseline parameter is assigned certain points, depending on its value, then the sum of all parameters is calculated. As a result, it is possible to determine the risk using a couple or three scales.

Overall, 169 patients were studied (mean age of 49.2, mean follow-up of 34 months). The most common cause of fistulas included hysterectomy (69.4%), followed by pelvic radiotherapy (18.9%). Only 64% of cases were primary fistula. Closure rate was 90.7% (98/108). Anatomical success depended on the surgical approach. For transvesical procedure, success rate was 89.4% (42/47), compared to 84% (89/106) and 87.5% (14/16), respectively for transvaginal and transabdominal success rate. According to Clavien-Dindo, complications were grade 1 (11.8%) and grade 2 (4.7%). As UDI-6 showed, the most common symptoms were frequency (62%), urgency (50%), incontinence (73%), pain (55%) and voiding symptoms (27%). Fistula size > 3.0 cm, pelvic radiation, and previous vaginal surgeries were associated with a higher risk of failure or more severe lower urinary tract symptoms. A high number of re-do cases and complex fistulas could be a limitation of this study. Factors for successful non-obstetric urogenital fistula closure were fistula size less than 3.0 cm, absence of pelvic radiation, and previous vaginal surgeries.

According to our results, only fistula size > 3 cm, previous vaginal procedures and pelvis irradiation were unfavorable predictors for anatomic success of fistula repair. In addition, our results allow to determine the predictors for successful repair and risk of recurrence lower urinary tract symptoms postoperatively.