The value of in vitro ultrasonography in the intraoperative staging of gastric cancer. Blind study of 93 cases.

The correct staging is of crucial importance in the choice of surgical treatment in patients affected by stomach carcinoma. In an attempt to achieve a greater accuracy in the diagnosis of depth of tumor invasion, we propose to perform ultrasonography of the gastric wall during surgery (in vitro ultrasonography). Immediately after removal by the surgeon, the portion of the stomach containing the tumor is submitted to ultrasonography with a linear 7.5-MHz probe. To obtain good ultrasonographic images it was necessary to interpose an echo-free standoff pad between the probe and the gastric wall and between the latter and support surface. On completion of ultrasonography, the surgical specimen was sent to the pathologist, who was unaware of the diagnosis formulated on the basis of in vitro ultrasonography (VUS). The VUS diagnosis of T corresponded to the pathological diagnosis in 87/93 cases (93.5% accuracy). In the early cancers the diagnosis was correct in 24/28 cases (85.7%); in the advanced cancers the diagnosis was correct in 63/65 cases (96.9%). In comparison with the results of the other preoperative and intraoperative techniques the accuracy of in vitro ultrasonography in diagnosing the depth of tumor invasion was clearly superior. We feel that VUS may become a basic instrument in T staging and an aid to the surgeon in deciding the extent of the resection and of lymphadenectomy in patients with gastric cancer.