Ultrasound of colonic neoplasia - An intraoperative tool?

Background: The accuracy of intraoperative ultrasound of the colon in the location and assessment of neoplastic lesions at the time of resection has not been reported. Methods: An in vitro study was performed, with ultrasound imaging of colonic specimens resected for malignancy, The specimens were imaged empty, surrounded by saline, the lumen filled with saline. Results: Excellent ultrasound images were produced, particularly when the colonic lumen was filled with saline. All lesions were located by this technique, and several impalpable synchronous polyps also were found. In two specimens, the remnants of a malignant polyp not visible with intraoperative colonoscopy 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 intraoperative probe, produced accurate images of neoplastic lesions in an in vitro setting. This technique may have a role in the intraoperative location and assessment of colorectal cancer.