The current role of intraoperative ultrasound during the resection of colorectal liver metastases: A retrospective cohort study.

INTRODUCTION: Liver resections with negative margins improve survival in patients with colorectal liver metastases (CRLM). Intraoperative ultrasound (IOUS) is a valuable tool that gives information about lesions that ultimately changes surgical strategy to ensure complete removal, which subsequently improves disease free survival (DFS).

METHODS: A retrospective review of patients who underwent a resection for CRLM from 2009 to 2012 was completed to determine the impact of IOUS.

RESULTS: A total of 103 patients had a hepatic resection for CRLM. All patients had preoperative imaging to assist with operative planning. IOUS was performed in 72 cases. Surgical strategy changed in 31 (43.1%) cases with IOUS, compared to three (9.7%) with no IOUS (P < 0.001). A new lesion was detected in 13 (18.1%) of the cases. A higher proportion of nonanatomic liver resections were performed in the IOUS group (N = 27, 37.5%) compared to the non-IOUS group (N = 6, 19.4%) (P = 0.07).

CONCLUSION: Achievement of a negative resection margin was comparable between the two groups. However, there was a trend toward improved DFS in the IOUS group. Despite advances in preoperative imaging, IOUS demonstrates utility in providing novel information that allows removal of the entire tumor burden, using parenchymal-preserving techniques when feasible, leading to improved DFS.