# Impact of centre volume on adrenalectomy outcomes: European multicentre study based on EUROCRINE® registry

## TL;DR

High-volume centers perform adrenalectomies with fewer complications, suggesting that centralizing these surgeries could improve patient outcomes.

## Contribution

Identifies a center volume threshold (≥36 adrenalectomies/year) linked to better surgical outcomes using a large European registry.

## Key findings

- High-volume centers had significantly lower rates of high-grade complications, conversion, and reoperation.
- A center volume threshold of ≥36 adrenalectomies per year was associated with better outcomes.
- Minimally invasive surgery and benign tumors were linked to lower complication risks.

## Abstract

The relationship between surgeon volume and patient outcomes in adrenalectomy is well established in the literature and clinical guidelines. However, evidence regarding the impact of centre volume on patient outcomes remains limited. This study aimed to evaluate the effect of centre volume on patient outcomes.

This multicentre study analysed adrenalectomy procedures from the EUROCRINE® registry (2015–2024). A volume threshold was determined using receiver operating characteristic curve analysis to predict high-grade complications (Clavien–Dindo grade ≥ III). Outcomes were compared between high- and low-volume centres, and multivariable logistic regression was used to identify independent predictors of complications and death.

A total of 6672 patients undergoing adrenalectomy from 99 centres across Europe were included. The optimal centre volume threshold was ≥ 36 adrenalectomies per year. Only seven centres (7%) met this threshold, accounting for 36.7% of all procedures. High-volume centres had significantly lower rates of high-grade complications (0.9 versus 2.9%; P < 0.001), conversion (2.3 versus 3.5%), and reoperation (0.7 versus 1.6%), and shorter hospital stays (median 2 versus 3 days). Multivariable analysis showed high-volume centre status to be independently protective against high-grade complications (odds ratio 0.39, 95% confidence interval 0.24 to 0.63; P < 0.001), but not postoperative mortality (odds ratio 0.69; P = 0.480). Functional benign tumours compared with malignant tumours (odds ratio 0.61, 0.39 to 0.93; P = 0.020) and minimally invasive surgery (odds ratio 0.21, 0.14 to 0.31; P < 0.001) were both associated with a significantly lower risk of high-grade complications.

Centre adrenalectomy volume is a key determinant of high-grade complication risk following adrenalectomy. A threshold of ≥ 36 adrenalectomies per year identifies high-performing centres. These findings support centralization of adrenal surgery to optimize outcomes and standardize care across institutions.

This multicentre retrospective study analysed 6672 patients who underwent adrenalectomy from the EUROCRINE® registry to assess the impact of annual centre volume on surgical outcomes. Receiver operating characteristic curve analysis identified ≥ 36 adrenalectomies per year as the optimal threshold, with high-volume centres showing significantly lower rates of high-grade complications. These findings support centralization of adrenal surgery to optimize outcomes and standardize care.