Ultrasound of colonic neoplasia - An intraoperative tool?

Background: The accuracy of intraoperative ultrasound of the colon in the l ocation and assessment of neoplastic lesions at the time of resection has n ot been reported. Methods: An in vitro study was performed, with ultrasound imaging of coloni c specimens resected for malignancy, The specimens were imaged empty, surro unded by saline, the lumen filled with saline. Results: Excellent ultrasound images were produced, particularly when the c olonic lumen was filled with saline. All lesions were located by this techn ique, and several impalpable synchronous polyps also were found. In two spe cimens, the remnants of a malignant polyp not visible with intraoperative c olonoscopy were found by specimen ultrasound. The clarity of the image was such that the cancer stage often could be assessed. Conclusions: Direct ultrasound of the colon, using a high-frequency intraop erative probe, produced accurate images of neoplastic lesions in an in vitr o setting. This technique may have a role in the intraoperative location an d assessment of colorectal cancer.