The accuracy of endorectal ultrasound in staging rectal lesions in patients undergoing transanal endoscopic microsurgery.

BACKGROUND: Endorectal ultrasound (ERUS) is used to preoperatively assess locoregional stage in patients with rectal neoplasms. This study evaluates the accuracy of ERUS in determining the T stage of rectal neoplasms treated by transanal endoscopic microsurgery (TEM).

METHODS: All patients in the St Paul's Hospital TEM database were evaluated and excluded if they had been treated with neoadjuvant therapy. ERUS results were compared with gold-standard postoperative histopathology reports. Tumor height from anal verge was measured by ERUS and endoscopic techniques.

RESULTS: Fifty-three patients were eligible to participate in the study. A Friedman test demonstrated significant difference in the T stage between ERUS and the histopathology reports (P < .001). The tumor height measured by ERUS is significantly higher than the height measured by endoscopy (P < .05).

CONCLUSIONS: This study confirms that ERUS often overstages rectal neoplasms and suggests that ERUS findings should not preclude TEM in clinically appropriate patients.