Hurlstone DP et al. (2005) 20-MHz high-frequency endoscopic ultrasound-assisted endoscopic mucosal resection for colorectal submucosal lesions: a prospective analysis. J Clin Gastroenterol 39: 596–599

High-frequency endoscopic ultrasound (HFUS) using a miniprobe accurately diagnoses and stages T1 mucosal and submucosal colorectal tumors. Hurlstone et al. have now shown that this technique can be a safe and effective guide for endoscopic mucosal resection (EMR) of these lesions, which means that patients could potentially be treated with a single-stage HFUS/EMR procedure. This finding represents a substantial improvement on conventional management, in which patients are typically offered either surgical resection or endoscopic observation, often without histologic diagnosis.

After an index colonoscopy to confirm the presence of a single mucosal or submucosal lesion <20 mm in diameter, 30 of 33 eligible patients had lesions that met the inclusion criteria and subsequently underwent HFUS-guided EMR. In three cases the lesion could not be detached from the muscularis propria and was surgically resected. The remaining 27 lesions were successfully excised by EMR, and histologic analysis showed that all 27 had negative resection margins. Only one patient suffered minor bleeding at the time of surgery; this low rate might be attributable to the use of an adrenaline-containing submucosal injection solution. No local recurrence was detected in any of the 27 cases at endoscopic follow-up (range 4–18 months). One limitation of the study, however, was that the EMR technique used was not suitable for lesions >20 mm.

While the results are encouraging, it is worth remembering that HFUS-guided EMR is currently recommended only for highly demarcated hypoechoic lesions without umbilication—those most likely to become malignant.