Clinical outcome following intraoperative computed tomography-assisted secondary orbital reconstruction

Abstract

Secondary post-traumatic orbital reconstructions are challenging. Portable computed tomography (CT) provides the option to acquire real-time, intraoperative images that help to detect the insufficient reconstruction of the orbit immediately. We retrospectively analyzed patients who received intraoperative CT imaging and analyzed the effect of intraoperative CT scans on revision rates and orbital volume changes before, during, and after surgery. From August 2014 to September 2016, eleven patients received intraoperative cone-beam CT scans to evaluate the results of secondary orbit reconstruction using Medpor + titanium implants. Patient demographics, surgical details, CT scanning protocol, and follow-up results were analyzed. 3D CT volumetry was used to analyze the orbital volume based on OsiriX MD software. Based on intraoperative CT findings, seven cases required intraoperative revision to further augment the orbital cavity or adjust implants. The mean preoperative measured enophthalmos was 3.41±1.4 mm (range: 2-6 mm), which decreased to 0.73±0.4 mm (range: 0-1 mm) at postop assessment (p<0.0001). On the fracture side, there was a significant difference between preoperative vs. intraoperative and preoperative vs. postoperative volume measurements (p<0.01 for both subsets), but no significant difference between intraoperative vs. postoperative measurements. Intraoperative CT is a valuable tool in secondary orbital reconstruction cases based on clinical enophthalmos evaluation and 3D CT volumetry. For these patients, the avoidance of another revision surgery may outweigh the disadvantage of increased operation time and additional radiation exposure.