The Impact of Preoperative Botulinum Toxin a (Bta) Injection on Subxiphoid (M1) Hernia Repairs

Background Preoperative relaxation of the abdominal wall with Botulinum Toxin A (BTA) injection can assist with fascial closure and decrease the need for component separation (CST). Its efficacy in subxiphoid (M1) hernias is unclear with high rates of CST reported despite BTA. For M1 hernias requiring CST, we assessed whether use of preoperative BTA offered any additional benefit toward fascial closure or recurrence rates. Methods A tertiary hernia center’s prospectively maintained database was reviewed for M1 hernias, as defined on CT imaging. Patients who underwent subsequent CST were grouped based on whether preoperative BTA injections were performed. Results Of 67 M1 hernia patients, 30 (44.8%) received BTA and 37 (55.2%) did not. BTA versus non-BTA groups had similar age (56.0 ± 14.1 vs. 61.5 ± 11.8 years; P = 0.087), ASA score, diabetes history, and defect size (499.2 ± 185.5 vs. 416.1 ± 238.6 cm2; P = 0.144). BTA group had lower BMI (28.9 ± 5.1 vs. 32.7 ± 7.2 kg/m2; P = 0.018), fewer current and former smokers (0% vs. 10.8%, 40.0% vs. 62.2%; P = 0.006), more contaminated and dirty cases (20.0% vs. 5.4%, 33.3% vs. 13.5%; P = 0.008), and more biologic mesh used (62.1% vs. 35.1%; P = 0.046). Neither panniculectomy rates nor CST techniques differed (external oblique release: 80.0% vs. 62.2%; P = 0.179, posterior rectus sheath release: 70.0% vs. 67.6%; P > 0.999, transversus abdominus release: 26.7% vs. 35.1%; P = 0.598). Rates of unilateral versus bilateral CST were not statistically different. There were no differences in fascial closure (90.0% vs. 94.6%; P = 0.650), recurrence (6.7% vs. 2.7%; P = 0.583), or in-total wound complication rates (33.3% vs. 43.2%; P = 0.458) between BTA and non-BTA groups with follow-up of 12.7 ± 18.8 versus 24.1 ± 28.2 months (P = 0.062). Conclusions M1 hernia repair often requires CST despite BTA injections. BTA as a preoperative adjunct in this population does not benefit fascial closure rates, risk of recurrence, or frequency of bilateral CST.