Chemical Components Separation: Concepts, Evidence, and Outcomes.

Ventral hernias with loss of domain pose a significant challenge to the hernia surgeon. Techniques such as advancement flaps, component separation, progressive pneumoperitoneum, and preoperative injection of botulinum toxin A (BTA) aim to alter the abdominal wall length or form to achieve tension-free primary fascial repair in abdominal wall reconstruction (AWR). Here, we review the current literature on BTA injection as an adjunct to AWR. A literature review identified 22 articles discussing the use of BTA associated with ventral hernia repair. Six primary studies reported preoperative use of BTA. Treatment regimens are not standardized, varying from 300 to 500 u injection on 3-5 sites per laterality, from 4 weeks before the day of surgery. After injection, computed tomography scans demonstrate elongated and thinned abdominal wall muscles with decreased mean defect size and hernia size. Primary fascial closure is usually achieved. Postoperative pain control may be improved with perioperative administration of BTA, and no adverse events associated with BTA injection were reported. Preoperative BTA injection is a promising adjunct to AWR, creating abdominal wall laxity and enabling primary fascial repair. Further investigation will be needed to determine the ideal dosage, timing, and patient population.