Injections of onabotulinumtoxinA prior to hernia surgery relaxed the abdominal muscles and increased abdominal wall length by an average of 8 cm, based on data from an observational study of 56 patients. The findings were published online in Surgical Endoscopy.
Although laparoscopic ventral hernia repair has a lower recurrence rate than open repair, expanding the abdominal wall remains a challenge, wrote Omar Rodriguez-Acevedo, MD, of the Hernia Institute Australia, Edgecliff, New South Wales, Australia, and colleagues (Surg Endosc. 2017 Jul 21.).
Nearly three-fourths of the patients (73%) had at least one previous repair. The patients underwent injections of either 200 units or 300 units of BTA between 7 and 14 days before surgery. The average age of the patients was 60 years, and the average body mass index was 40 kg/m2. A subset of 18 patients with larger defects underwent preoperative progressive pneumoperitoneum (PPP) in addition to receiving BTA injections.
Overall, BTA injections significantly increased lateral abdominal length in all subgroups. On average, the length increase per side was 4.4 cm in the 300-unit group, 3.6 cm in the 200-unit group, 4.2 cm in the BtA-only group, and 3.7 cm in the BTA-plus-PPP group. In a pooled analysis, the average gain in length was 4.0 per side.
No significant difference in abdominal wall lengthening was observed between the 200-unit and 300-unit patients or between the BTA-plus-PPP and BTA-only patients.
Overall, the injections were well tolerated, and no complications required intervention, the researchers said. The most common side effects included superficial bruising at the injection site, bloating sensations, weak coughing, and back pain.
The findings were limited by the small study population and by the short follow-up period, and additional long-term follow-up is needed to identify delayed hernia recurrence, the researchers noted. However, the results suggest that “the flaccid paralysis delivered by BTA resulted in the relaxation, elongation, and thinning of the chronically contracted abdominal lateral wall musculature,” which “consequently facilitates laparoscopic repair and primary closure of large defects under minimal tension,” they said.
The researchers had no financial conflicts to disclose.