Effectiveness of pre-operative chemical component separation with computed tomography-guided intramuscular injection of OnabotulinumtoxinA in outcomes of large complex incisional ventral abdominal hernia repair: a propensity score-weighted comparative analysis.

PURPOSE: To evaluate the effectiveness of chemical component separation (CCS) via computed tomography (CT)-guided intramuscular injection of OnabotulinumtoxinA (Botox) in postoperative recurrence of large complex incisional ventral abdominal hernias. MATERIALS AND METHODS: A total of 97 patients with large ventral abdominal hernias who underwent complex hernia repair between November 2017 and October 2021 after (n = 37) (Botox) or without (n = 60) Botox injection (no-Botox) were included in the study. Data were summarized as median [min-max] or frequency (%) and analyzed using the Fisher's exact test, Mann-Whitney U test, multivariate logistic regression with backward stepwise selection of covariates and augmented inverse probability-weighted analysis with Stata BE 18.0 at a significance level set at 0.10. RESULTS: There was no statistically significant difference between Botox and no-Botox groups in patients' age (64[34-78] vs. 62[24-94], p = 0.885), sex (females: 46% vs. 55%, p = 0.410), body mass index (BMI) (32[19-53] vs. 31[18-50], p = 0.431) and hernia volume (3197[226-24232] vs. 2366[140-24314], p = 0.458). Median follow-up duration was 38[2-72] months in Botox and 48[6-81] months in no-Botox groups (p = 0.010), and all-time hernia recurrence was 8% in Botox and 22% in no-Botox groups, respectively (p = 0.097). In multivariate regression analysis, CCS, hernia volume, implanted mesh type and overall postoperative complications were associated with hernia recurrence. After propensity score weighting for follow-up duration, surgical component separation and postoperative discharge destination, CCS was associated with 71% reduced risk of hernia recurrence (p = 0.045). CONCLUSION: The results of this study suggests that CT-guided chemical component separation with intramuscular injection of OnabotulinumtoxinA may be effective in reducing the risk of post-surgical recurrence of large complex incisional ventral abdominal hernias.