Outcomes of chemical component paralysis using botulinum toxin for incisional hernia repairs

Background: Botulinum toxin A (BTX) confers flaccid paralysis and pain modulation when injected into a muscle. We hypothesized that long-term paralysis of the abdominal wall musculature (i.e., chemical component paralysis, CCP) would benefit incisional hernia repair (IHR) by decreasing postoperative pain, the use of opioid analgesia, and thus opioid-related side effects. Methods: Adult patients who underwent elective IHR with preoperative CCP (n = 22) were compared to concurrent matched controls (n = 66, 1:3 ratio) based on age (±5 years), sex, body mass index (±5 kg/m²), history of hernia recurrence (0 vs. ≥1), and type of repair (open vs. laparoscopic). BTX was injected under ultrasonographic guidance into the transversus abdominis and internal and external oblique muscles at three sites bilaterally (300 units total). Results: Patients who underwent IHR with CCP used significantly less opioid analgesia (mean ± SD morphine equivalents) when compared to controls on hospital days (HDs) 2 and 5: HD2, 48 ± 27 versus 87 ± 41; HD5, 17 ± 16 versus 48 ± 45. Likewise, CCP patients reported significantly less pain (visual analogue scale 1-10) when compared to controls on HD2 (5.2 ± 1.5 vs. 6.8 ± 2) and HD4 (3.6 ± 1.2 vs. 5.2 ± 1.9): all p < 0.007 (Bonferroni adjusted). There was no difference in postoperative complications (surgical site, 9 vs. 14 %), opioid-related adverse events (ileus 5 vs. 5 %), hospital stay (4 ± 3 vs. 3 ± 2 days), or hernia recurrence (18 months mean follow-up: 9 vs. 9 %). Conclusions: Despite similar multimodality treatment of postoperative pain after IHR, patients who underwent CCP required significantly less opioid analgesia and reported less pain.