Surgical Planning of Hepatic Metastasectomy Using Radiologist-Performed Intraoperative Ultrasound

Background: Intraoperative ultrasound (IOUS) of the liver is a useful adjunct for surgical planning during hepatic metastasectomy. This study aims to (1) report the frequency of change in operative plan as a result of IOUS findings and (2) determine whether IOUS is still beneficial after implementing a standardized, comprehensive process of preoperative hepatic imaging. Methods: First, a retrospective review of all patients undergoing hepatic metastasectomy at a single institution was conducted to identify how frequently IOUS findings altered the surgical plan. Second, a prospective study was conducted where patients underwent both preoperative CT and MRI within 30 days before surgery to determine if IOUS may still have benefit despite the implementation of a standardized preoperative imaging protocol. Results: In the retrospective review, 39 liver resections were completed; 100% and 36% of patients underwent preoperative CT and MRI, respectively. The mean time between preoperative imaging and surgery was 46 days (7-126). Operative plans were changed in 10/39 (26%) cases based on IOUS. After the standardization of preoperative imaging, 27 liver resections were performed. All patients underwent preoperative CT and MRI; the mean time between preoperative imaging and surgery was 20 days (1-98) (p=0.001). The operative plan was amended in 5/27 (19%) cases based on IOUS (χ 2=1.405, p=0.24). Conclusion: Even after standardizing the quality and timing of preoperative imaging, the operative plan was changed in nearly 1/5 patients due to IOUS. These findings demonstrate the utility of IOUS in surgical planning for hepatic metastasectomy and provide the basis for a quality improvement strategy regarding standardized preoperative imaging.