Abdominal wall dynamics after component separation hernia repair

Background: The component separation technique (CST) is an important technique now used frequently in complex ventral hernia repair (VHR). Although this technique has demonstrated superior success rates, there is a paucity of research describing how release of the external obliques coupled with rectus myofascial advancement alters the morphology of the abdominal architecture. In this study, we apply the new concept of analytic morphomics to describe the immediate changes in morphology of the abdomen that take place after VHR by CST. Methods: We identified 21 patients who underwent VHR by CST and received both preoperative and postoperative computed tomography scans between 2004 and 2009 in our clinical database. The surgical technique involved incisional release of the external oblique muscle lateral to the linea semilunaris with rectus abdominis myofascial advancement in all patients. Using semiautomated morphomic analysis, we measured the pre- and postoperative dimensions of the abdominal wall including the anterior-posterior distance from the anterior vertebra-to-skin and fascia along with the circumferential area of the skin and fascial compartments. Paired Student t-tests were used to compare pre- and postoperative values. Results: After hernia repair, there was a decrease in the anterior vertebra-to-skin distance (16.6 cm-15.8 cm, P = 0.007). There were also decreases in total body area (968.0 cm²-928.6 cm², P = 0.017) and total body circumference (113.6 cm-111.4 cm, P = 0.016). The distance from fascia to skin decreased as well, almost to the point of statistical significance (3.3 cm-2.9 cm, P = 0.0505). Interestingly, fascia area and circumference did not decrease significantly after the operation (578.2 cm²-572.5 cm², P = 0.519, and 89.1 cm-88.6 cm, P = 0.394, respectively). Conclusions: Morphomic analysis can be used to compare and pre- and post-operative changes in patients undergoing abdominal surgery. Our study demonstrates that component separation affects the dimensions of the entire abdomen, but leaves the fascia area and circumference relatively unchanged. These changes in the abdominal wall may help explain the muscular changes observed as a result of this operation and demonstrate that this is a functional operation that restores fascial area. By better defining the effects of this procedure, we can better understand the reason for its clinical success.