MIAMI BEACH – Intraoperative ultrasound during resection of colorectal liver metastases changed operative management in 43% of cases, according to a retrospective study.
Ultrasound employed during surgery identified new lesions not seen on preoperative imaging, and gave additional details about known lesions, said Dr. Sarah Knowles, a surgical resident at the University of Western Ontario, London (Canada).
"Intraoperative ultrasound provided new information about the number, size, location, and appearance of the lesions," she said at the annual meeting of the Americas Hepato-Pancreato-Biliary Association. The procedure was associated with significantly more blood loss, however, and there were no differences in negative surgical margins between patients who had ultrasound during surgery and those who did not.
Dr. Knowles presented a retrospective study of 103 patients who, from 2009 to 2012, underwent liver resection of colorectal cancer metastases. Mean age of the patients was 62 years. Most (94%) had undergone preoperative computerized tomography; the rest had undergone magnetic resonance imaging. The mean time from preoperative imaging to surgery was 66 days. Most of the patients (72) had intraoperative ultrasound imaging.
There were 45 anatomic resections and 27 nonanatomic resections in the group that had intraoperative ultrasound. This was significantly different from the nonultrasound group, which had 25 anatomic and 6 nonanatomic resections.
Ultrasound changed surgical strategy in 43% (31) of those who had it. Surgical strategy changed in 10% of those who had no intraoperative imaging – a significant difference (P = less than .001). Blood loss was significantly greater in the ultrasound group (650 mL vs. 350 mL).
The bulk of the strategic changes in the ultrasound group (17) were due to additional information about the location of lesions – either deeper or more superficial than preoperative imaging suggested. Other reasons for a shift in strategy were the discovery of new lesions (13), a disappearing lesion (1), larger-than-expected lesions (5), smaller-than-expected lesions (2), or a difference in the lesions’ appearance (3).
Resection margins were similar in the two groups. In the ultrasound group, 85% had R0 margins and 15% had R1 margins. In the group without ultrasound, 87% had R0 margins and 13% had R1 margins. There was no significant difference in disease-free 5-year survival.
Dr. Knowles had no financial disclosures.