LUSSY score predictive of failure of surgical closure of obstetric rectovaginal fistula in the Democratic Republic of the Congo

Abstract

Introduction: Rectovaginal fistula (RVF) is a complex debilitating condition that results from several etiologies, obstetric trauma being the most common. Occasionally RVF closure is non-successful. The objective of this study is to develop a predictive score to identify predictors of failure of surgical closure of obstetric RVF (FSCORVF) in the Democratic Republic of the Congo. Methods: This was an analytical cross-sectional study conducted on 268 patients with obstetric RVF who have received surgical management. We proceeded with a bivariate and then multivariate analysis. Score discrimination was assessed using the ROC curve and C-index and score calibration was done according to the Hosmer–Lemeshow test. Results: Surgical closure of RVF failed in 12.31% of cases (33/268). After logistic modelling, five criteria emerged as predictive factors of FSCORVF (LUSSY Score): the presence of moderate/severe fibrosis (aOR: 36.25; 95% CI: 1.88–699.37), combined RVF with other type of fistula (aOR: 61.41; 95% CI: 8.78–429.72), fistula size > 3 cm (aOR: 82.45; 95% CI: 10.48–648.58), per-operative hemorrhage (aOR: 27.84;; 95% CI: 5.08–152.47) and postoperative infection (aOR: 1161.35; 95% CI: 46.89–28765.47). A score of 0 to 22 was obtained with a value ≤ 9 points indicating a low risk of FSCORVF, a value between 10 and 12 defining a moderate risk and the value ≥ 13 points corresponding to a high risk of FSCORVF. The area under the ROC curve of the score is 0.9744 with a sensitivity of 90.91%, a specificity of 97.87%, a positive predictive value of 85.71% and a negative predictive value of 98.71%. Conclusion: This study identified predictive factors for FSCORVF in the DRC, grouped in the LUSSY score. Complex fistulas (fistula size > 3 cm, severe fibrosis, combined fistulas) require advanced surgical routes different from the transvaginal and the transperineal ones used in the present study. Prevention of intraoperative hemorrhage and postoperative infections requires rigorous preparation, appropriate antibiotic prophylaxis, and strict postoperative follow-up.