Impact of adrenal surgeon volume on outcome: analysis of 4464 operations from the United Kingdom Registry of Endocrine and Thyroid Surgery (UKRETS)

Abstract Background There is a surgeon volume–outcome effect in adrenal surgery but the threshold for high-volume surgeon remains controversial. This study aimed to determine predictors of high-risk adrenal operations and to explore whether these should be restricted to high-volume surgeons. Methods Patients undergoing adrenal surgery and registered in the United Kingdom Registry of Endocrine and Thyroid Surgery between 2004 and 2021 were analysed. Outcomes included postoperative complications, duration of hospital stay, and mortality. Factors included in multivariable analysis were age, sex, diagnosis, surgical approach, laterality, and surgeon volume. Patients with missing data were excluded. Results A total of 4464 of 6174 patients (72.3%) were analysed. Postoperative complications occurred in 418 patients (9.4%) and 14 (0.3%) died. Median duration of hospital stay was 3 (i.q.r. 2–5) days. Co-variables significantly associated with an increase or decrease in postoperative complications (P < 0.050) were age (OR 1.02, 95% c.i. 1.01 to 1.03), adrenal cancer (OR 1.64, 1.14 to 2.36), minimally invasive approach (OR 0.317, 0.248 to 0.405), bilateral surgery (OR 1.66, 1.03 to 2.69), and surgeon volume (OR 0.98, 0.96 to 0.99). An increase or decrease in mortality was associated with patient age (OR 1.08, 1.03 to 1.13), minimally invasive approach (OR 0.08, 0.02 to 0.27), and bilateral surgery (OR 6.93, 1.40 to 34.34). The incidence of postoperative complications was significantly lower above a threshold of 12 operations per year (P = 0.034) and 20 per year (P < 0.001), but not six per year (P = 0.540). Median duration of hospital stay was 2 days for surgeons doing over 20 operations per year, compared with 3 days for those undertaking fewer than 20, fewer than 12 or fewer than 6 operations per year. Conclusion Increasing surgical volume is associated with shorter hospital stay and fewer complications. This analysis supports the case for centralization of surgery for adrenal cancer and bilateral tumours to higher-volume surgeons performing a minimum of 12 operations per year.