Therapeutic outcomes in 1000 cases of endoscopic submucosal dissection for early gastric neoplasms: Korean ESD Study Group multicenter study.

BACKGROUND: The technique of endoscopic submucosal dissection (ESD) was introduced to be able to obtain en bloc specimens of large early GI neoplasms. The drawback of ESD is its technical difficulty, which, consequently, is associated with a higher rate of complication and which requires advanced endoscopic techniques and a long procedure time.
OBJECTIVE: To assess the therapeutic outcome of ESD by expert endoscopists who have at least 3 years' experience of EMR in Korea.
DESIGN: A retrospective, multicenter study. PATIENTS: From January 2006 to June 2007, 1000 early gastric cancers in 952 patients (502 men, 450 women; mean age 62.1 years, range 43-90 years) were treated by using ESD at 6 Korean ESD study group (KESG)-related university hospitals in Korea. INTERVENTION: We performed ESD procedures with typical sequences (marking, incision, and submucosal dissection). MAIN OUTCOME MEASUREMENTS: The rate of en bloc resection, incidence of complication, and length of procedure. Predetermined factors (various endoscopic and final pathologic features) for these outcomes.
RESULTS: The rates of en bloc resection, complete en bloc resection, vertical incomplete resection, and piecemeal resection were 95.3%, 87.7%, 1.8%, and 4.1%, respectively. The rates of delayed bleeding, significant bleeding, perforation, and surgery related to complication were 15.6%, 0.6%, 1.2%, and 0.2%, respectively. The mean procedure time was 47.8 +/- 38.3 minutes. The rates of en bloc resection differed significantly in relation to the location of the lesions (upper portion vs middle portion vs lower portion of the stomach, 88.6% vs 95.2% vs 96.0%, respectively; P = .02), presence of a scar (no vs yes, 96.0% vs 89.5%, respectively; P = .002), and histologic type (low-grade adenoma vs high-grade adenoma vs differentiated early gastric cancer vs undifferentiated early gastric cancer, 95.8% vs 94.6% vs 96.2% vs 83.8%, respectively; P = .007). The rates of delayed bleeding differed significantly in relation to location (upper portion vs lower portion of the stomach, 28.6% vs 13.8%, respectively; P = .003), the size of the tumor (>40 mm vs <20 mm, 28.6% vs 13.7%, respectively; P = .009), recurrent lesion (29.4% vs 15.1%, respectively; P = .024), and macroscopic type (flat vs elevated, 18.8% vs 12.4%, respectively; P = .047). Factors related to the longer procedure time were location (upper portion vs lower portion of the stomach, 64.8 vs 44.1 minutes, respectively; P < .001), the size of the tumor (>40 mm vs < 20 mm, 67.1 vs 42.0 minutes, respectively; P < .001), the presence of ulcer (54.6 vs 46.8 minutes; P < .045), and the presence of a scar (69.2 vs 45.0 minutes; P < .001).
CONCLUSIONS: ESD is an effective and safe therapy in the management of early gastric neoplasms. Endoscopists have to accept the need for advanced endoscopic techniques for performing ESD in the case of large lesions, scar lesions, undifferentiated cancers, or for the lesions in the upper portion of the stomach. Endoscopists require more experience to decrease complications in patients who have a large or recurrent lesion in the upper portion of the stomach; these lesions also take more time to complete the ESD procedure.