Purpose: Categorize data to investigate the surgeon volume outcome relationship in thyroidectomies. Determine the evidence base for recommending a minimum number of thyroidectomies performed per year to maintain surgical competency.
Methods: Data on thyroid operations in the United Kingdom Registry of Endocrine and Thyroid Surgery (UKRETS) from 01/09/2010 to 31/08/2016 was analysed. The primary outcome measure was permanent hypoparathyroidism (PH). Recurrent laryngeal nerve palsy (RLN) and post-operative haematoma were also examined. Exclusion criteria included patient age > 85 or < 18 years, and surgeons contributing <10 operations. Data analysis was performed using general additive models and mixed effect logistic regression for PH and binary logistic regression for others.
Results: For PH 10313 bilateral thyroid operations were analysed. The Annual rate (AR, p = 0.012) and nodal dissection (P < 10-7) were significant factors. 25,038 thyroidectomies were analysed to investigate the effect of surgeon Volume on RLN palsy and haematoma. Age, retrosternal goitre, routine laryngoscopy, re-operation, nodal Dissection, bilateral thyroidectomy, RLN monitoring and surgeon volume were significantly associated with RLN palsy. Post-operative haematoma showed no significant correlation to surgeon volume. Categorisation of AR showed that PH and RLN palsy rates declined in surgeons performing >50 cases/year to a minimum of 3% and 2.6% respectively in highest volume AR group (>100 cases/year).
Conclusion: Surgeon annual operative volume is a factor in determining outcome from thyroid surgery. Results are limited by a high proportion of missing data, which could potentially bias the outcome, but tentatively suggests the minimum recommended number of thyroid operations / year should be 50 cases.
Keywords: Chronic hypocalcaemia, permanent hypoparathyroidism, operative volume; Endocrine surgery; Surgeon volume; Thyroidectomy; Volume-outcome.