Botulinum toxin A-induced paralysis of the lateral abdominal wall after damage-control laparotomy: A multi-institutional, prospective, randomized, placebo-controlled pilot study

Background Damage-control laparotomy (DCL) is a lifesaving operation used in critically ill patients; however, interval primary fascial closure remains a challenge. We hypothesized that flaccid paralysis of the lateral abdominal wall musculature induced by botulinum toxin A (BTX) would improve rates of primary fascial closure, decrease duration of hospital stay, and enhance pain control. Methods Consenting adults who had undergone a DCL at two institutions were prospectively randomized to receive ultrasound-guided injections of their external oblique, internal oblique, and transversus abdominus muscles with either BTX (150 mL, 2 U/mL) or placebo (150-mL 0.9% NaCl). Patients were excluded if they had a body mass index of greater than 50, remained unstable or coagulopathic, were home O₂ dependent, or had an existing neuromuscular disorder. Outcomes were assessed in a double-blinded manner. Univariate and Kaplan-Meier estimates of cumulative probability of abdominal closure were performed. Results We randomized 46 patients (24 BTX, 22 placebo). There were no significant differences in demographics, comorbidities, and physiologic status. Injections were performed on average 1.8 ± 2.8 days (range, 0-14 days) after DCL. The 10-day cumulative probability of primary fascial closure was similar between groups: 96% for BTX (95% confidence interval [CI], 72-99%) and 93% for placebo (95% CI, 61-99%) (HR, 1.0; 95% CI, 0.5-1.8). No difference between BTX and placebo groups was observed for hospital length of stay (37 days vs. 26 days, p = 0.30) or intensive care unit length of stay (17 days vs. 11 days, p = 0.27). There was no difference in median morphine equivalents following DCL. The overall complication rate was similar (63% vs. 68%, p = 0.69), with two deaths in the placebo group and none in the BTX group. No BTX or injection procedure complications were observed. Conclusion The use of BTX after DCL was safe but did not seem to affect primary fascial closure, hospital length of stay, or pain modulation after DCL. Given higher-than-expected rates of primary fascial closure, Type II error may have occurred. Level of Evidence Therapeutic study, level III.