Obstetric fistula: evaluation with ultrasonography.

Twenty-two patients with 24 fistulae were examined prospectively with real-time sonography. Sonographic findings were compared with those of intravenous urograms and correlated with the findings at examination under anesthesia and at surgery. Various genital abnormalities not revealed by intravenous urography were demonstrated by sonography preoperatively. These included cervical injuries, vesicovaginal fistula showing "flat tire" sign and hourglass deformities, and identification of the site, size, and course of fistulae in seven (29%) of the cases. However, the demonstration of the fistulae by sonography is poor relative to that of examination under anesthesia, in which 21 (87%) of the fistulae were identified. The factors responsible for the difficulty in demonstrating the fistulae on sonography, which included size and multiplicity, are discussed. Sonography is complementary to examination under anesthesia in preoperative evaluation of the patients with obstetric fistulae in general and in those with previous unsuccessful repairs in particular.