Among adults who have complex gastrointestinal (GI) cancer surgery, those who receive care from high-volume anesthesiologists have a lower risk of adverse postoperative outcomes compared with those who receive care from low-volume anesthesiologists, according to a study in JAMA Surgery.

The population-based cohort study examined the association between anesthesiologist volume and short-term postoperative outcomes in patients who have had complex GI cancer surgery. Patients aged 18 years or older who had been diagnosed with GI cancer from January 1, 2007, to December 31, 2018, from health care data sets in Ontario, Canada, were eligible.

The study authors defined primary anesthesiologist volume as the mean annual number of procedures (esophagectomy, pancreatectomy, and hepatectomy) supported by the anesthesiologist in the 2 years before the index surgery. Anesthesiologist volume was dichotomized into low-volume and high-volume groups, and the 75th percentile or 6 or more procedures per year were selected as the cutoff points. A composite of 90-day major morbidity, including mortality and hospital readmission, was the primary outcome.

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The study included 8096 patients—5369 men (66.3%), median age 65 years (interquartile range [IQR], 57-72 years). A total of 842 anesthesiologists and 186 surgeons treated the patients, and the median anesthesiologist volume was 3 procedures (IQR, 1.5-6 procedures) per year. The median surgeon volume was 27 procedures (IQR, 15-45 procedures) per year, and the median institutional volume was 373 procedures (IQR, 127-712 procedures) per year.

A total of 2166 patients (26.7%) received care from high-volume anesthesiologists. The primary outcome was observed in 787 of 2166 patients (36.3%) in the high-volume group compared with 2709 of 5930 participants (45.7%) in the low-volume group. Care from a high-volume anesthesiologist was independently associated with lower odds of the primary composite outcome (adjusted odds ratio [aOR], 0.85; 95% CI, 0.76-0.94).

Care from a high-volume anesthesiologist was independently associated with lower odds of 90-day major morbidity (aOR, 0.83; 95% CI, 0.75-0.91) and unplanned intensive care unit admission (aOR, 0.84; 95% CI, 0.76-0.94). Care from high volume anesthesiologists was not associated with lower odds of mortality or readmissions (aOR, 0.87; 95% CI, 0.73-1.05), though it was associated with a smaller number of events (n = 402; aOR, 1.05; 95% CI, 0.84-1.31).

The association between outcomes and volume remained when the study authors examined 30-day outcomes, with an odds ratio of 0.81 (95% CI, 0.73-0.88) for care by high-volume anesthesiologists compared with care from low-volume anesthesiologists. In addition, the E-value for the association between anesthesiologist volume and the primary composite outcome was 1.63, indicating that an unmeasured variable would be unlikely to substantively change the risk estimates.

The researchers noted several limitations to this retrospective study. The data were not collected specifically to answer the research question, and consistent staging information was not available to assess the extent of disease.

“We believe that the findings support organizing perioperative care to increase anesthesiologist volume and healthcare organizations that facilitate care delivery by high-volume anesthesiologists for complex GI cancer surgery,” the researchers commented.

Disclosures: Two of the study authors reported affiliations with pharmaceutical companies. Please see the original reference for a full list of disclosures.


Hallet J, Jerath A, Turgeon AF, et al. Association between anesthesiologist volume and short-term outcomes in complex gastrointestinal cancer surgery. JAMA Surg. Published online March 17, 2021. doi: 10.1001/jamasurg.2021.0135