With approval from the Institutional Review Board of Northwestern University, twenty-one patients with large ventral hernias were selected due to their large hernia size from a pool of 130 patients undergoing abdominal wall reconstruction from January 2007 to December 2008. No patients were excluded based on co-morbid conditions. One patient of the 21 selected was excluded because his preoperative CT scan that was performed at an outside institution was stored in an incompatible format for analysis. Another patient was excluded because it was decided intra-operatively that she could be repaired in a tension-free manner without components separation and was closed with mesh alone. Standard abdominal and pelvic CT scans and pulmonary function tests were performed immediately before hernia repair, and 3 months after repair. Pulmonary function tests were interpreted by blinded members of the Department of Pulmonology. Intra-operative peak airway pressure, bladder pressure, postoperative oxygen requirement, diagnosis of pneumonia, and any other cardio-respiratory complications were recorded on the remaining 19 patients. Routine patient demographics, clinical characteristics, postoperative course and incidence of recurrence were prospectively collected on all patients. Statistical analysis was performed in an intention-to-treat manner, using paired student's t-test where applicable.
