Evolution of thyroid surgery: unravelling complications from the 1930s to the modern era – a retrospective cohort study

STUDY AIMS: At the beginning of the 20th century, iodine deficiency was prevalent and goitre was a frequent indication for thyroid surgery. At that time, the hospital in Riehen (Switzerland) was an established centre for thyroid surgery. This study investigates the specific complications associated with thyroid surgery over time. METHODS: An analysis of thyroidectomy data from two retrospective cohorts of the Riehen hospital was performed for two decades: 1930-1939 (shortly after the start of salt iodination in Switzerland) and 1970-1979 (salt iodination well established). Demographics, clinical and surgical characteristics, and postoperative complications were compared. The primary endpoint included the rate of mortality, Chvostek tetany and recurrent laryngeal nerve injuries. We also compared last-century data with modern-era data consisting of Swiss diagnosis-related group (DRG) data on thyroidectomies for the years 2011-2015 and EUROCRINE registry data for the year 2024 (including data of endocrine surgical interventions from the five largest Swiss surgical centres). RESULTS: Among 3280 thyroidectomies analysed (1826 for 1930-1939 and 1454 for 1970-1979), the 1930s cohort was younger (mean age: 37.3 years, standard deviation (SD): 11.1 years vs 49.9 years, SD: 13.2 years; p <0.01) and more predominantly female (85.5% vs 83.1%; p <0.01). Compared to the 1930s, in the 1970s the weight of the resected thyroid gland had decreased (mean thyroid weight: 141.2 g, SD: 99.9 g vs 107 g, SD: 89.3 g; p <0.01) and there were lower rates of recurrent laryngeal nerve injuries (16% vs 4.2%; p <0.01) and Chvostek tetanies (6.1% vs 1%; p = 0.01). Modern-era data indicate a lower thyroidectomy mortality rate than in the 1970s. CONCLUSION: The reduction in complications following thyroidectomy over time seems to be multifactorial. While iodine supplementation and a decrease in goitre size played a role in the Riehen cohorts, advancements in surgical skills and perioperative management may also have contributed to the even more favourable outcomes in the modern era.