Post-surgical vesico-vaginal fistula: CT diagnosis and follow-up

Clinical History

A female patient with previous radical hysterectomy plus radiotherapy for endometrial carcinoma four years earlier, underwent repeated surgery for left-sided pelvic neoplastic recurrence and was discharged after an uneventful postoperative course.
Afterwards, she began complaining of vaginal discomfort and discharge, without abnormal findings (particularly identifiable fistulous orifices) at gynaecological examination.

Imaging Findings

Compared to previous studies, preoperative CT (Fig. 1) showed appearance of a 3 cm peripherally enhancing lesion consistent with local neoplastic recurrence.
Three weeks after pelvic surgery, CT including multiplanar excretory-phase images (Fig. 2) showed well-distended opacified urinary bladder with Foley catheter and left-sided ureteral stent in place, bilaterally normal nephrographic and pyelographic appearances, nondilated collecting systems and lateral retraction and opacification of the vagina through a short communication indicating vesicovaginal fistula.
Treatment included electrocoagulation of vaginal fistulous orifice, long-term antibiotics and ureteral stenting. Six months later CT-urography (Fig. 3) showed persistent vaginal opacification through a high-output supratrigonal vesicovaginal fistula.
One year after surgery repeated CT (Fig. 4a…c) showed absent vaginal opacification indicating fistula closure, without signs of tumour recurrence. With ureteral stent still in place, follow-up CT three years after surgery (Fig. 4d…g) showed ipsilateral decreased renal size and parenchymal thickness, appearance of ureteropelvic mural thickening interpreted as chronic infectious pyeloureteritis, and persistently healed vesicovaginal fistula.

Discussion

In the developing world, obstructed labour still represents the main cause of vesico-vaginal fistulas (VVFs). Conversely, in Western countries the vast majority of VVFs currently result from surgical trauma [1, 2].
Despite technical advancements and improved experience in open and laparoscopic surgery, iatrogenic urogenital injuries still complicate up to 1% of all gynaecologic and pelvic operations. Among all urogenital postoperative complications, VVFs (approximately 2% of cases) are rare occurrences compared to bladder (60-70%) and ureteral (24-30%) injuries. Nevertheless, VVFs represent the commonest (more than two-thirds) type of iatrogenic pelvic fistulas. The risk of developing a VVF is highest (7.4%) during radical hysterectomy, mostly related to extensive parametrial and nodal dissection, and is further increased by pelvic adhesions and previous irradiation [3-6].
The classical manifestations of VVFs include continuous urinary leakage, foul smelling or discharge from the vagina, and frequently associated perineal dermatitis. Despite overt clinical signs, the actual visualization of the abnormal fistulous communication is often quite difficult at cystoscopy and vaginal exploration [1, 2].
Imaging plays an increasingly pivotal role in the diagnosis and management of postoperative complications after gynaecologic surgery, which include haemorrhage, infection/abscess, bowel perforation or obstruction, bladder perforation, ureteral injuries, and uretero-, vesico- or recto-vaginal fistulas [5, 7, 8]. Traditionally intravenous urography and cystography were used to demonstrate the fistulous tract between the bladder neck and the vaginal stump representing a VVF. Conversely, nowadays cross-sectional imaging with CT and MR mostly replaces radiographic studies. The presence of air or fluid in the vaginal lumen on unenhanced CT images suggests a VVF, which is confirmed by extravasated opacified urine at CT-urography or CT-cystography. As this case exemplifies, multiplanar CT image reformations allow precise identification of site, length and direction of the abnormal tract, and differentiation from other possible complications - particularly a uretero-vaginal fistula [3, 5, 7, 8].
A minority (10%) of VVFs seal spontaneously with prolonged urethral catheterization, antibiotics and electrocoagulation. Conversely, most cases ultimately require surgical treatment, which should be postponed after healing of devitalized tissue and vaginal cuff, pelvic or urinary tract infections in order to reduce the recurrence rate. The transvaginal approach is preferred, but several alternative techniques include transvesical, supravesical or transabdominal approaches, with high success rate (75-97%) and possible (10-33%) recurrences [1, 2, 9, 10].

Differential Diagnosis List

Final Diagnosis

Iatrogenic supratrigonal vesicovaginal fistula after pelvic surgery for recurrent uterine cancer

URL:	https://www.eurorad.org/case/12239
DOI:	10.1594/EURORAD/CASE.12239
ISSN:	1563-4086