Endosonography and endosonography-guided biopsy of upper-GI-tract tumors using a curved-array echoendoscope.

Background: The purpose of the present study was to evaluate the accuracy of endoscopic ultrasonography (EUS) with a curved-array transducer and to determine the value of endosonography-guided biopsy.
Methods: EUS was performed in 162 consecutive patients for preoperative staging of gastric or esophageal cancer (n = 122) or for EUS-guided biopsy (n = 40). All patients were examined using a flexible echoendoscope (Pentax FG32-UA) equipped with a 7.5-MHz curved-array transducer. A specially designed fine needle was used for EUS-guided biopsy of submucosal or extrinsic lesions.
Results: Surgery was performed in 19 of 48 patients with esophageal cancer and 60 of 74 patients with gastric cancer. The accuracy in the assessment of the infiltration depth of esophageal cancer and in the determination of lymph node involvement was 84% and 88%, respectively. In gastric cancer the tumor infiltration depth was assessed correctly in only 65% of the patients. The identification of early gastric cancer proved to be a major problem. The accuracy in the detection of lymph node involvement was 73%. Obstructing tumors were examined in 17 patients with carcinoma of the esophagus or the gastric cardia. The accuracy of EUS in determining the T-stage and the N-stage of stenotic tumors was 88% and 86%, respectively. Endosonography-guided needle biopsy was successfully performed in all 40 patients. Histologic analysis revealed malignancy in 50% of the patients. Only two biopsy specimens contained nonrepresentative material (accuracy: 95%). No complications were observed related to the procedure.
Conclusions: EUS with a curved-array transducer provides high accuracy rates in staging of esophageal carcinoma. Evaluation of gastric cancer with this technique appears to be more difficult than with radial transducers. A major advantage of the linear transducer is the ability to perform EUS-guided biopsies of submucosal or extamural lesions.