Echo-guided liver resection of invisible and non palpable metastatic colorectal cancer

Aims: Several experiences underline that in many cases a neoplastic lesion, especially hepatic metastases from colorectal cancer (CRC), may be missed by surgical inspection and palpation, even if correctly demonstrated by an ideal preoperative imaging assessment. The role of intraoperative ultrasonography (IOUS) in detecting and localizing invisible and nonpalpable CRC liver metastases nodules was evalueted. Methods: In a series of 83 histologically demonstrated CRC liver metastases nodules in 67 patients, liver resection was carried out under ultrasonographic control. Hepatectomies, segmentectomies, systematic sub-segmentectomies and hepatic wedge resections were performed. Results: IOUS showed the presence and the location of 8 (10%) invisible and non palpable lesions, that were resected in all cases. Out of 22 lesions ≤ 1 cm in diameter, 5 (23%) were occult to surgical evaluation, so that 3/39 (8%) nodules 1-5 cm in diameter. All 22 tumours more than 5 cm in diameter were palpable. Among patients with single CRC liver metastases, 5/57 (9%) nodules were detected only by IOUS, compared with 2/10 (20%) in subject with multicentric CRC liver metastases. Conclusions: US intraoperative detection of invisible and nonpalpable CRC liver metastases nodules can be mandatory to avoid blind resections, allowing a selective surgical approach. IOUS role is especially demonstrated in detecting and localizing CRC liver malignancies.