173: Endoscopic Resection Techniques

Introduction

Endoscopic resection (ER) of early neoplastic lesions in the gastrointestinal tract has become increasingly important in recent years, both as a diagnostic tool and as a method of performing definitive treatment when the cancer meets certain criteria in which the risk of lymph node metastasis is negligible.¹

Indications for Endoscopic Resection of Early Esophageal Carcinoma

Adenocarcinoma in Barrett Esophagus

The indications for ER in esophageal adenocarcinoma are high-grade intraepithelial neoplasia (HGIN) and mucosal cancer. Risk stratification should be carried out in accordance with known risk factors such as grade of differentiation, lymphatic or venous infiltration, and the infiltration depth of the carcinoma. The limitations of ER in early Barrett cancers should be submucosal infiltration or infiltration of the lamina muscularis mucosa in combination with another risk factor, such as poor tumor differentiation or lymphatic and venous infiltration. The largest series ever published on endoscopic treatment of early Barrett neoplasia showed a long-term complete response in 94.5% of patients. Long-term survival of patients treated for Barrett neoplasia in this series did not significantly differ from that of the normal German population with the same age and gender distribution.²

Squamous Cell Carcinoma of the Esophagus

In esophageal squamous cell neoplasia (SCN), ER should only be carried out if the carcinoma is limited to the mucosal layer as has been shown in several publications.^3,4

Preprocedure Assessment

Accurate staging is mandatory before endoscopic treatment of early esophageal cancer. The most important part of the staging procedure entails careful evaluation of the neoplasia and the borders of the lesion using a high-resolution endoscope, and a thorough search for multifocal neoplasia. In addition, the macroscopic type of the lesion should be determined, as it has been shown to have significant correlation with infiltration depth.^5,6 Conventional endoscopic ultrasound (EUS) and EUS with miniprobes (20 or 30 MHz) can be carried out to evaluate the depth of infiltration and the lymph node status of the tumor. However, the accuracy of T staging is limited, particularly for distinguishing between the important stages of T1 m and T1 sm. The diagnostic accuracy of submucosal cancer ranges from 33% to 85%.^7–11 Underdiagnosis by EUS has been shown in 12.5% to 67% of cases.^7,8 In contrast, EUS is highly accurate in differentiating T1 and T2 tumors.⁹

Endoscopic Resection Techniques

“ER” is the general term for the different resection techniques used to treat neoplastic and uncertain lesions in the gastrointestinal tract. The term “endoscopic mucosal resection” is widely used; however, it is misleading because significant proportions of the submucosal layer are also resected, which is important in the case of submucosal infiltration of the tumor.

Endoscopic Resection with ...