Does Surgeon Volume Impact Morbidity Following Parathyroidectomy? A Study of 16,140 Parathyroidectomies from the UK Registry of Endocrine and Thyroid Surgery (UKRETS) Database

Background Outcomes in endocrine surgery have been shown to improve with surgeon volume. We aimed to study the effect of surgeon volume on morbidity following parathyroidectomy. Methods UKRETS data from 2004 to 2019 was studied. Parathyroidectomies for primary hyperparathyroidism with complete data were included. Exclusion criteria were age <18 or >80 years; surgeons contributing <10 cases overall; and length of stay >28 days. Multivariable analysis was performed. Primary outcome was persistent hypercalcaemia; secondary outcomes were haemorrhage, length of stay, need for re-admission, post-operative hypocalcaemia, and need for calcium/vitamin D supplements to maintain eucalcaemia at 6 months. Results 153 surgeons undertook mean 22.5 (median 17, range 2–115) parathyroidectomies/year. Persistent hypercalcaemia affected 4.8% (776/16140) overall; 5.7% (71/1242) in surgeons undertaking < 10 cases/year; 5.1% (3339/6617) for 10–30 cases/year; 5.0% (270/5397) for 30–50 cases; and 3.3% (96/2884) for >50 cases/year. High-volume (>50 parathyroidectomies/year) surgeons operated 23.4% (809/3464) of negative localisation cases compared to 16.4% (2074/12676) of positive localisation cases. Persistent hypercalcaemia was almost twice as common in image negative (7.9%) compared to image-positive (4%) cases. Persistent hypercalcaemia was significantly more likely to occur in the low volume (<10 parathyroidectomies/year) group than high volume (>50 parathyroidectomies/year), regardless of image positivity ( p = 0.0006). Surgeon volume significantly reduced persistent hypercalcaemia on multivariable analysis (OR = 0.878, 95%CI 0.842–0.914, p < 0.001), along with age, sex, and positive localisation. BNE and re-operation significantly increased persistent hypercalcaemia. Post-operative hypocalcaemia occurred in 3.2% (509/16040) and was reduced with increasing surgeon volume (OR = 0.951, 95%CI 0.910–0.993, p < 0.001). Haemorrhage and length of stay were not significantly associated with surgeon volume. Conclusion The incidence of persistent hypercalcaemia, post-operative hypocalcaemia, and persistent hypoparathyroidism decreased with increasing surgeon volume. The relative reduction in persistent hypercalcaemia with surgeon volume was similar in image negative and positive groups, but the absolute reduction was higher in image negative cases. Restricting image negative parathyroidectomy to high-volume surgeons could be considered.