Does sarcopenia have a negative impact on the efficacy of botulinum toxin A in the prehabilitation of patients undergoing incisional hernia repair? A multicentric retrospective study.

[BACKGROUND] Botulinum toxin A (BTA) injections are increasingly used to prepare patients undergoing surgery for incisional hernias larger than 10 cm. The aim of this study was to analyze the impact of sarcopenia on the efficacy of BTA injection in lengthening the lateral abdominal muscles.

[METHODS] Between August 2018 and January 2024, patients with midline incisional hernias ≥ 10 cm undergoing preoperative BTA injections were included in a multicentric database. Sarcopenia was evaluated calculating the muscle area measured on a transverse CT scan at the level of the L3 lumbar vertebra. Muscle characteristics and the volumes of the incisional hernia and abdominal cavity were compared before and 4 to 6 weeks after BTA injection. The effect of BTA on muscle elongation was evaluated according to sarcopenia.

[RESULTS] Fifty-nine patients were included. Sarcopenia did not impair the efficacy of BTA in terms of length of the lateral abdominal wall muscles, with a 1.8 cm increase bilaterally in each group. Regarding the efficacy of BTA injection, 80% of patients experienced elongation of the lateral abdominal wall muscles. Failure of the injection therefore affected 20% of patients. These results were similar in both groups, regardless of sarcopenia. Analysis of the characteristics of 'responders' and 'nonresponders' revealed that 'nonresponders' had a greater length of the lateral abdominal wall muscles on the scan prior to BTA injection, likely due to less significant muscle retraction.

[CONCLUSION] Sarcopenia did not impair the effectiveness of BTA in terms of elongation prior to incisional hernia repair.