Learning curve for endoscopic submucosal dissection of gastric neoplasms

Endoscopic submucosal dissection (ESD) is a widely accepted method for the treatment of early gastrointestinal neoplasms.

To investigate the learning curve of ESD performed by a single endoscopist focusing on developing the performance of dissection, shortening the procedure time, and preventing complications.

Records of 120 consecutive ESD procedures performed by a single endoscopist with an ESD knife from December 2007 to April 2013 were collected. For analysis of the learning curve, total procedures were divided into four periods, each comprising 30 sequential ESD procedures. Adjusted procedure time (min) was calculated as specimen area [π×long length (mm)×short length (mm)/4]÷procedure time. The parameters assessed were the en-bloc resection rate, complete resection rate, duration and speed of procedure time, and related complications.

Procedure times were significantly longer with lesions located at the upper third of the stomach and with the specimen sizes exceeding 1500 mm. There were significant differences in the adjusted overall procedure time from the first to the third quarter (19.9±11.0 vs. 30.3±11.8, P=0.01) and to the fourth quarter (19.9±11.0 vs. 35.8±15.7, P<0.01), and from the second to the third quarter (21.1±8.3 vs. 30.3±11.8, P=0.04) and to the fourth quarter (21.1±8.3 vs. 35.8±15.7, P<0.01).

ESD for gastric neoplasms can be performed with a steady speed after the experience of 60 ESD procedures with proper clinical outcomes. Further studies with different endoknives will be required for ESD operators as a reference.