Formation of vesicovaginal fistula after modified McDonald cerclage placement: a case report with literature review.

Cervical cerclage is a common procedure employed to prevent preterm birth in women with cervical insufficiency. Complications such as injuries to the cervix and bladder, and premature membrane rupture are well-documented, while genitourinary fistulas are a rare occurrence. This article reports a rare case of vesicovaginal fistula (VVF) formation in a 27-year-old woman following the placement of a McDonald cervical cerclage. The patient presented with continuous watery vaginal leakage, which began during the last 2 months of her pregnancy. Clinical and cystoscopic examinations revealed the presence of a VVF, which was further confirmed through voiding cystourethrography and perineal magnetic resonance imaging. Notably, the patient had undergone the cerclage procedure 18 months prior to the onset of symptoms, making this case particularly unusual. We believe that the VVF formation was associated with the use of Mersilene tape, which may have slowly eroded through the cervix and subsequently breached the urothelium. This case underscores the importance of considering cerclage-related genitourinary fistulas as potential complications, especially when evaluating and counseling patients who have undergone cervical procedures like the McDonald technique. In conclusion, this case highlights the need for vigilant monitoring and a high index of suspicion in patients presenting with symptoms of genitourinary fistulas after such procedures. Further research and awareness in this area are warranted to better understand the risk factors and mechanisms underlying this unusual complication.