Benchmark values for transthoracic esophagectomy are not set as the defined "best possible"-a validation study

Background: Recently, benchmark values for low-comorbidity patients at high-volume centers were set to define "best achievable results" for transthoracic minimally invasive esophagectomy (MIE). We aimed to validate suggested benchmark values by comparing them to outcomes at a medium-volume center in Finland. Methods: All MIEs (n=82) performed at Central Finland Central Hospital between September 2012 and November 2017 Including 75 totally MIE and 7 hybrid procedures. The aim of die study was to compare the results to previously suggested benchmark parameters for postoperative morbidity measured with the Clavien-Dindo classification and comprehensive complication index. Target benchmark parameters were <= 55.7% for any complications, <= 30.8% for major complications (Clavien-Dindo >= 3a), <= 40.8% for 30-day and <= 42.8% for 90-day comprehensive complication index, <= 20% for anastomosis leak, <= 31.6% for pulmonary complications, <= 1.0% for 30-day mortality and <= 4.6% for 90-day mortality. Results: Compared with benchmark patients, our patients were older (median 68 vs. 58 years), with more comorbidities. All parameters measuring complications showed better results in out study than benchmark values. Median intensive care unit stay of 1 (IQR, 1-1) and hospital stay of 9 (IQR, 9-12) days were also shorter. At least 1 complication developed in 45.1%, and 6.1% faced major morbidity. Median (IQR) comprehensive complication index for both 30 and 90 days was 0 (IQR, 0-20.9 days). Anastomosis leak and pulmonary complications were observed in 3.7% and 22.0%, respectively. The 30- and 90-day mortality was 1.2% (1/82). Conclusions: Benchmark values assessing postoperative morbidity after MIE do not represent the defined "best achievable" results after completed learning curves.