Endoscopic ultrasonography for assessing the horizontal extent of invasive gastric carcinoma.

Accurately determining the surgical resection line is essential for improving the prognosis of patients with gastric carcinoma. Endoscopic ultrasonography (EUS) was used to assess the horizontal extent of cancerous invasion below the mucosal layer. In 105 patients (110 lesions) with gastric carcinoma, ultrasonographic images of resected specimens were compared with histological findings. The horizontal extent of the hypoechoic region of in vitro ultrasound was compared with the horizontal extent of the cancerous invasion and fibrosis in histological sections. In cases showing echo patterns characteristic of peptic ulcerations within the tumor focus, the horizontal spread of the echo-poor region correlated well with the spread of fibrosis, but not with the cancerous lesion. In other cases with no ulceration, the horizontal spread of the echo-poor region corresponded well with the cancerous lesions. To evaluate oral invasion of the cancerous lesion below the mucosa, 16 patients with gastric carcinoma who had clips placed during endoscopy were subsequently examined by EUS. The use of EUS combined with the clips allowed for a more accurate diagnosis of the invasion, not only in the mucosa, but also into the submucosa and beyond. This combined diagnostic method was safe and useful for determining a suitable surgical resection line.