Background and aim: For the purpose of precise preoperative diagnosis that ensures complete endoscopic resection, it is important to accurately determine the lateral spread of gastric cancer lesions. The acetic acid + indigocarmine (AI) method used by us has been found to meet this need. This paper reports its usefulness in the determination of lateral spread of gastric cancer before endoscopic submucosal dissection (ESD).
Methods: The present study was conducted in 114 patients who were operated on for an early-stage gastric cancer, after determining the lateral spread of cancerous lesions by the AI method, between September 2005 and December 2006. The negative lateral stump reaction rate obtained in ESD was conducted in areas delineated by the AI method. The borderline clarification rate obtained by the AI method and the indigocarmine (I) method were compared between the lesions with and without clear borders under observation with the naked eye.
Results: The lateral stump after ESD conducted using the AI method was histologically negative in 111 of the 114 patients (97%). The lesion spread was clarified by the AI method in 103 patients (90%): 55 (95%) and 48 (86%) patients with and without clear macroscopic lesion borders, respectively. Compared to the I method, the AI method clarified the lesion spread in a significantly higher percentage of patients with macroscopically unclear lesion borders (P = 0.015).
Conclusion: The present study stresses that the AI method should be used to conduct ESD more safely and accurately in patients with well or moderately differentiated adenocarcinoma.