Hypothesis / aims of study
Vesicovaginal fistulae (VVF) have a significant negative impact on quality of life, with failed surgical repair resulting in ongoing morbidity. Our aim was to characterize the rate of VVF repair and repair failures over time, and to identify predictors of repair failure.
Study design, materials and methods
We completed a population-based, retrospective cohort study of all women who underwent VVF repair in Ontario, Canada, aged 18 and older between 2005-2018. Risk factors for repair failure were identified using multivariable cox proportional hazard analysis; interrupted time series analysis was used to determine change in VVF repair rate over time.
Results
814 patients underwent VVF repair. Of these, 117 required a second repair (14%). Mean age at surgery was 52 years (SD 15). Most patients had undergone prior gynecological surgery (68%), and 76% were due to iatrogenic injury. Most repairs were performed by urologists (60%). Predictors of VVF re-repair included iatrogenic injury etiology (HR 2.1, 95% CI 1.3-3.45, p=0.009), and endoscopic repair (HR 6.1, 95% CI 3.1-11.1, p<0.05,); protective factors included combined abdominal/vaginal repair (HR 0.51, 95% CI 0.3-0.8, p=0.009), and surgeon years in practice (21+ years - HR 0.5, 95% CI 0.3-0.9, p=0.005). Age adjusted annual rate of VVF repair (ranging from 0.8 to 1.58 per 100,000 women) and re-repair did not change over time.
Interpretation of results
Risk factors for secondary repair were iatrogenic injury as VVF etiology, and endoscopic treatment (fulguration or fibrin glue) as repair. It is not surprising that endoscopic repair was a risk factor for repair failure. This approach is often used for elderly patients attempting to avoid invasive surgery, or as a first resort with the knowledge that definitive repair may become necessary. Iatrogenic injury as VVF etiology was twice as likely to result in the need for VVF re-repair, as compared to malignancy, obstetrical trauma, endometriosis, radiation, and other. This finding is difficult to explain, as one might expect the etiologies to result in poor tissue healing following initial repair. We theorize that this finding may be due to unknown factors not accounted for in this study – perhaps anatomic location or size of VVF, or time from diagnosis to repair. Protective factors found included combined abdominal/vaginal repair and physician years in practice. Specifically, an abdominal approach decreased the risk of a re-repair by 50%. We suspect this is due to the nature of the fistula itself, and less so the surgical approach. Location of fistula is often the determining factor in surgical approach, which we did not capture in our study.
Physician years in practice was associated with a decreased risk of VVF re-repair. Index repairs by surgeons with 21+ years of practice compared to those with 1-5 years of practice were half as likely to result in re-repair. In the literature, whether surgeon experience improves outcomes and complication rates has been mixed.
We examined changes to repair rates over time and found a significant decrease in repair rates of annual VVF repair per 100,000 women, by 0.14 each year from 2005-2009. From 2009 onward this rate continued to decrease, but not significantly. When age-standardized this decrease was not found. Over our 13-year study period the rate of VVF repairs and re-repairs did not change year to year. This may be due to lack of surgical advances in VVF repair, specifically robot-assisted repair, which have not become common place in Canada. Robotic-assisted VVF repair has become popular in other countries and may represent an opportunity for improved repair rates.