Optimal Hospital Volume to Minimise Mortality After Esophagectomy for Cancer in Low Population Density Countries: In Australia and New Zealand

Abstract Background A relationship between hospital volume and postoperative mortality following esophagectomy for cancer has been reported in the UK and Europe, leading to centralisation of surgery for esophageal cancer in most of these countries, including the Netherlands. It is unclear if this is replicated in countries with low population density such as Australia and New Zealand (ANZ). This study determined the relationship between hospital volume and mortality following esophagectomy in ANZ to define optimal hospital caseload. Methods As the standard of care following esophagectomy in ANZ is admission to an intensive care unit (ICU), the prospective ANZ Intensive Care Society Adult Patient Database was used to identify patients undergoing esophagectomy from 2005–22. In-hospital mortality was first determined for hospitals with annual caseloads defined as high (18+), medium-high (12–17), medium-low (6–11) and low (1–5). To define optimal caseload, mortality was also analysed against hospital volume using piecewise linear regression and non-linear (restricted cubic spline) methods. Results 6234 patients underwent esophagectomy in 161 hospitals, 25% of procedures were performed in low-volume hospitals (n = 1558), and 19.9% in high-volume hospitals (n = 1239). Overall, in-hospital mortality ranged from 0.73% in the high-volume hospitals to 5.71% in the low-volume hospitals. High-volume hospitals also had a shorter length of stay in hospital (p 0.001) and ICU (p 0.001). The optimal annual hospital volume for the lowest mortality was identified as 21 cases/year. After adjusting for confounders in multivariable analysis, low-volume hospitals showed the highest risk of mortality with ORs of 3.98 (low), 3.39 (medium-low), 3.32 (medium-high) vs high-volume (all p 0.05). Conclusion A positive volume-outcome relationship in ANZ was demonstrated for mortality following esophagectomy, with hospitals performing 21 or more surgeries per year delivering lowest mortality, which is similar to the previous European studies.