Prospective Measurements of Intra-Abdominal Volume and Pulmonary Function After Repair of Massive Ventral Hernias With the Components Separation Technique

Objective: To assess the effect of components separation on abdominal volume and pulmonary function after repair of hernias with loss of domain. Summary of Background Data: Immediate postoperative abdominal compartment syndrome is a feared complication after hernia repair in patients with a "loss of abdominal domain." Replacement of the viscera within an unyielding stiff abdominal wall may compromise the perfusion of the intestines, elevate the diaphragm, and interfere with ventilation. The components separation technique, used to repair these massive hernias, employs bilateral relaxing incisions in the external oblique muscle and fascia to approximate the rectus abdominis muscles in the midline. Methods: Nineteen consecutive patients with large ventral hernias were enrolled. Intra-abdominal volumes were prospectively measured before and after hernia repair, using computer analysis of abdominal CT scans. Pulmonary function tests were similarly obtained before and after surgery. Statistical analysis was performed using paired student's t test. This study was registered at clinicaltrials.gov (ID# NCT00894582). Results: Nine women and 10 men ages 24 to 76 with an average BMI of 30 kg/m(2) had an average hernia size of 915 mL. Intra-abdominal volume increased significantly after separation of parts hernia repair from an average of 7640 to 8166 mL (P = 0.01). Diaphragm height did not change significantly (37.1 cm to 37.5 cm, P = 0.42). Intraoperative peak airway pressures remained within normal limits for all patients. Pulmonary function testing revealed no significant differences before and after surgery. Conclusions: The components separation repair technique acts to restore lost abdominal domain by increasing its volume, and can be performed on patients with large ventral hernias with acceptable outcomes and without measurable changes in pulmonary function.