Evolving Practices in Low-Risk Papillary Thyroid Cancer: Impact of the 2015 ATA Guidelines

<b>Background/Objectives</b>: The extent of initial surgical resection for low-risk papillary thyroid carcinoma (PTC) remains debated. Traditionally, total thyroidectomy (TT) has been the standard approach, although the 2015 American Thyroid Association (ATA) guidelines endorsed a more conservative strategy. The real-world adoption of these recommendations, however, is unclear. This study evaluated changes in the surgical management of low-risk PTC in a high-volume center following the implementation of the ATA guidelines and analyzed the impact on postoperative outcomes. <b>Methods</b>: We conducted a retrospective study of 1644 patients who underwent surgery for localized low-risk PTC < 4 cm between 2014 and 2023. Temporal trends in the initial surgical procedure (TT vs. thyroid lobectomy [TL]) were analyzed overall and by tumor size and patient demographics. The need for completion thyroidectomy after TL and postoperative outcomes were also assessed. <b>Results</b>: The use of TL increased from 0% in 2014 to 59.4% in 2023 (<i>p</i> < 0.001). For microcarcinomas, TL rose from 17.5% in 2016 to 78% in 2023, with similar but less pronounced trends for 1-2 cm tumors. TT remained predominant for nodules > 2 cm. The completion thyroidectomy rate declined from 32% in 2016 to 4% in 2022. Patients undergoing TT experienced higher rates of postoperative complications (12.4% vs. 3.0%), particularly transient hypoparathyroidism (8.9% vs. 0%), and permanent hypoparathyroidism (1.8% vs. 0%), as well as longer operative time and hospital stay (all <i>p</i> < 0.001). The incidence of hypoparathyroidism decreased over time as TL use increased. <b>Conclusions</b>: Adoption of the 2015 ATA guidelines has progressively increased the use of TL in the management of low-risk PTC. This shift in surgical practice is associated with a reduction in the overall postoperative complication burden at the population level, largely driven by decreased hypoparathyroidism. Although guideline uptake has been gradual, current trends suggest increasing acceptance of less aggressive surgical strategies in routine clinical practice.