Risk factors for postoperative ileus after corrective spinal surgery: association with reduction in the retrocrural space area.

The objective of this study was to determine whether a reduction in the retrocrural space (RCS) area is a risk factor for postoperative ileus (POI) in patients with adult spinal deformity (ASD) treated with spinal corrective surgery. In total, 100 patients (mean age 67.5 ± 8.3 years, 9 males and 91 females) with ASD treated with spinal corrective surgery were included in this study. Spinal parameters, including thoracolumbar kyphosis (TLK), and RCS area were measured pre- and postoperatively. The change (Δ) in spinal parameters was calculated. The percent change between pre- and postoperative RCS areas was calculated as ΔRCS. Patients were identified as having POI if they exhibited both gastrointestinal symptoms and radiographic findings. Each parameter was compared between patients with and without POI. Multivariable logistic regression analysis was performed with development of POI as the dependent variable. The incidence of POI was 11.0%. The RCS area was significantly smaller in the POI group than in the non-POI group (p < 0.001). Multivariable logistic regression analysis revealed that ΔTLK and ΔRCS were risk factors for POI (p = 0.029 and p = 0.033, respectively). A reduction in the RCS area is a risk factor for the development of POI after corrective spinal surgery in patients with ASD. Overcorrection of the thoracolumbar junction should be avoided to prevent POI.