Endoscopic Mucosal Resection (EMR) Using the Insulation-Tipped Diathermic Knife (IT Knife) Allows Curative Resection of Residual or Recurrent Gastric Cancer After EMR

Abstract

Background: Repeat EMR to cure local recurrence of gastric cancer is difficult to perform because the initial EMR causes submucosal fibrosis. In turn, submucosal fibrosis causes the commonly used EMR techniques (strip biopsy, ligation, and cap techniques), to be performed piecemeal. Pathological evaluations of piecemeal-resected specimen are often ‘unable to be evaluated’ and thus leading patients to undergo additional palliative therapy such as APC or laser therapy. Without proper staging information, patients may also undergo unnecessary surgery. Newer technique of EMR using the IT knife (EMR-IT) allows submucosal dissection through the fibrosis and thus providing an en-bloc resection. We studied the safety and efficacy of EMR-IT and compared the results to historical controls. Methods: We used our prospectively entered database (1993 to 2003) to identify all patients who had locally recurrent gastric cancers that were treated with repeat EMR. We defined the resections as curative when the lateral and vertical margins were free of cancer. We recommended surgery when resection margin could not be evaluated to be free of cancer or there was submucosal invasion and/or vessel involvement. We used the Fisher's exact test for statistical analysis. Results: Among 61 recurrent gastric cancers, 38 cancers were resected completely in one piece. 43 patients had EMR-IT and 18 had other conventional procedures. EMR-IT led to en-bloc resected specimen in 38 patients (88.4%) as compared to in 0 patient (0%) in other conventional procedures (P < 0.0001). Non-evaluable specimen was only 1 lesion (2.6%) in the total 38 en-bloc resections compared with 10 lesions (43.8%) in the total 23 piecemealed-resection (P < 0.0001). 3 residual tumors (30%) were found in the total 10 non-evaluable specimens. There was no evidence of additional recurrence in curative group (en-bloc;30, peacemeal; 9 lesions) or distant metastasis among the patients who underwent curative EMR during a follow-up period of median 25 months (range; 6 to 68 months). There were 3 perforations by EMR-IT; all were successfully treated endoscopically using the endoclips. Conclusions: EMR-IT allows curative resection of local recurrent gastric cancer after EMR, and allows resections to be performed through submucosal fibrosis and provides en-bloc specimen. In turn, en-bloc resections allow precise staging and prevent residual disease/recurrence.