Usefulness of a novel electrosurgical knife, the insulation-tipped diathermic knife-2, for endoscopic submucosal dissection of early gastric cancer

Background. Although endoscopic submucosal dissection (ESD) of early gastric cancer using an insulation-tipped diathermic (IT) knife enables the removal of large and ulcerative lesions en bloc, expert endoscopic skill is required. We developed an improved IT knife (IT-2) and compared its efficacy and safety with that of the original IT knife (IT-OM). Methods. We performed ESD of 602 gastric cancers. Of these, 314 previously untreated single lesions of initial onset were analyzed. Operating time, rate of en-bloc resection, and incidence of complications were compared in the IT-2 group (161 patients) and IT-OM group (153 patients). Lesions were further analyzed as to whether they met the Japanese Gastric Cancer Association indications for ESD or extended indications. Results. Mean resection time was significantly shorter in the IT-2 than in the IT-OM group (48 vs 63 min). There were fewer surgeries lasting longer than 2 h in the IT-2 group than in the IT-OM group (3% vs 12%). En-bloc and margin-free resection rates in the IT-OM and IT-2 groups were 95% and 99%, respectively. Perforations occurred in 3.9% of patients in the IT-OM group and in 5% of patients in the IT-2 group (difference not significant [ NS]). The incidence of postoperative hemorrhage was 7.8% in the IT-OM group and 8.7% in the IT-2 group (NS). In both groups, complications were treated endoscopically, and emergency surgery was unnecessary. Conclusion. Resectability and complication rates were similar in the two groups. However, operating time was shorter with IT-2, irrespective of the indications for the performance of ESD. This study suggests benefits of the IT-2 over the IT-OM.