ABSTRACT
Objective To evaluate the value of ultrasonic mini probe(UMP) in the diagnosis of lower digestive tract lesions . Methods one hundred and fifteen patients with lesions of lower digestive tract were undergone EUS with UMP (Olympus UM-3R, 20MHz; UM-2R, 12MHz). Results Eighty one cases with colorectal carcinoma appeared as a hypoechoic mass under UMP. UMP had an overall accuracy rate of 82. 7% (67/81) in the diagnosis of depth of infiltrative colorectal carcinoma. The sensitivity and specificity of UMP in the diagnosis of lymph node metastasis were 55. 4% and 68. 8% respectively. All 15 cases with submucosal tumors were diagnosed correctly under EUS except one leiomyoma misdiagnosed as leiomyosarcoma and other 10 and 9 cases were ulcerative colitis and Crohn's diseases respectively. Conclusions UMP has a high accuracy in determining the invasive depth of colorectal carcinoma and submucosal tumors. The preoperative UMP may provide much information and influence on the choice of therapy for colorectal carcinoma and submucosal tumors.