Background:Outcomes after open esophagectomy (OE) have been shown to depend on institution case volume. We aim to determine whether a similar relationship exists for minimallyinvasive esophagogastrectomy (MIE). Methods: Patients who had OE or MIE (excluding robotic procdures) between 2010 and 2013 in the National Cancer Database were included. Outcomes included 30-and 90-day mortality, length-of-stay, hospital readmission, margin positivity, and number of lymph nodes harvested. Logistic and linear regression were used to adjust for possible confounders including age, gender, tumor size, Charlson score, induction therapy, and type of institution (academic vs. community-based). Results:We identified 2371 patients in the MIE group and 6285 patients in the OE group. In multivariate analysis, high case volume was an independent predictor for lower 30-day, 90-day mortality, shorter length-of-stay, and higher rate of negative-margin resection in OE (P<0.001) but not MIE. After quartile ranking of institutions based on volume, MIE outcomes were found to be better in institutions in the highest volume quartile compared to those in the lowest (p< 0.0001). Conclusions:In this dataset, MIE postoperative outcomes, unlike OE, did not correlate with hospital case volume. Volume-outcome relationships may be affected by surgical approach.The effect of case volume on long-term outcomes after MIE warrants further study.

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