Simulation study on the regionalization of esophagectomy using data from 27,476 patients in Japan

Although a strong volume-outcome association for esophagectomy has been reported in Japan, no national policy for regionalization currently exists. This study simulated the impact of regionalization on operative mortality, patient travel distance, and geographic disparities using a nationwide clinical database.

Patients who underwent esophagectomy with reconstruction for malignant tumors were identified from the Japanese National Clinical Database. Four simulation scenarios were established by setting minimum volume standards (MVSs) at 2, 5, 10, and 15 cases annually. Operative mortality in each simulation scenario was estimated using a model that incorporated both the post-regionalization hospital case volume and the characteristics of reassigned patients. Changes in travel distance were also evaluated across the metropolitan, provincial, and rural regions.

Among 27,476 patients treated across 1,041 hospitals, 76% of hospitals performed < 5 cases annually. The operative mortality decreased with increasing hospital volume (< 2 cases/year: 4.8%, ≥ 15 cases/year: 1.6%). Based on the simulations, applying MVSs of 2, 5, 10, and 15 reduced the mortality rates to 2.7%, 2.1%, 1.8%, and 1.7%, respectively-corresponding to 8-29 fewer deaths annually. However, 7%-38% of patients would need to travel to the nearest eligible hospital. In metropolitan areas, an MVS of 15 would increase the median travel distance by 2.6 km only. In rural areas, the distance would increase by 24 km at an MVS of 2 and by 43 km at an MVS of 15.

Regionalization of esophagectomy in Japan could significantly reduce operative mortality. However, it would increase travel burdens among patients in rural areas. Therefore, balancing outcome improvement and accessibility will be essential for policy implementation.