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Esophagectomy for cancer: clinical concerns support centralizing operations within the larger hospitals.

Esophagectomy needs experienced surgical techniques and a well-trained perioperative care team. There are now many reports that the mortality rate after esophagectomy is higher in those hospitals with a low volume of esophagectomy and/or low surgeon's volume. The purpose of this study is to decide the respective numbers of esophagectomy operations per year to define low-volume and high-volume hospitals in Japan. If medical policy aims to further reduce mortality and morbidity associated with esophagectomy, then esophagectomy operations should be further centralized, away from low-volume hospitals, into high-volume hospitals. The Japanese Association for Thoracic Surgery has accumulated the surgical outcomes from 31 380 esophagectomy operations, registered from 709 institutes during the period from 2001 to 2006. These institutes are here classified into six groups according to the number of esophagectomy operations per year as 4 or less, 5-9, 10-19, 20-39, 40-79, and 80 or more. Using a statistical model-selection procedure by information criteria, these six groups are then classified into three categories as low-volume, medium-volume, and as high-volume hospitals. Among the 31 380 patients registered, overall, 390 patients (1.2%) died within 30 days, and 1187 patients (3.8%) died during the primary hospital stay. The odds ratio of the greatest volume group to the minimum volume group was 0.307 for the 30-day mortality rate, and 0.288 for the in-hospital mortality rate. For both the 30-day mortality rate and the in-hospital mortality rate, a hospital with less than five esophagectomy operations per year was classified as a low-volume hospital. A hospital with 40 or more esophagectomy operations per year was classified as a high-volume hospital. Concerning the number of esophagectomy operations performed per year in Japan, low-volume hospitals are defined as those where esophagectomy is performed less than five times per year, and high-volume hospitals are defined as those where esophagectomy is performed 40 or more times per year. If medical policy in Japan aims to further decrease the mortality after esophagectomy, then esophagectomy operations should be limited in these identified low-volume hospitals.