Intraoperative mapping of the recurrent laryngeal nerve and parathyroid glands to improve thyroid surgery outcomes

To perform an intraoperative topographic analysis of the recurrent laryngeal nerve (RLN) and parathyroid glands during thyroid and parathyroid surgery, focusing on their relationship with the inferior thyroid artery (ITA), RLN branching patterns, and glandular positioning. Based on a high-volume surgical cohort, the study proposes a standardized dissection approach to reduce RLN injury and postoperative hypoparathyroidism.

A retrospective cohort of 500 patients undergoing thyroidectomy and/or parathyroidectomy between 2011 and 2021 was analyzed. All cases followed a uniform dissection technique emphasizing consistent neurovascular identification. A total of 773 RLNs were documented. The RLN-ITA relationship was classified as retroarterial, prearterial, or interarterial. RLN bifurcation and parathyroid gland topography were systematically recorded. Intraoperative nerve monitoring (IONM) was selectively applied. Postoperative complications were assessed.

RLN identification was achieved in 99.2% of cases. Retroarterial positioning predominated on the left (70.3%), while prearterial and interarterial courses were more common on the right (51.1% and 30.5%, respectively; p < 0.01). RLN bifurcation occurred in 32.5%, more often on the right (44.6% vs. 27%, p = 0.001). Superior parathyroid glands were consistently high (84.1%), whereas inferior glands were predominantly low (71%), with 29% in middle positions. IONM confirmed nerve function in 87.7% of monitored cases. Transient RLN paresis occurred in 1.2%, permanent paralysis in 0.7%, and permanent hypoparathyroidism in 6.7%.

A standardized dissection focused on neurovascular landmarks ensures high nerve and parathyroid glands identification rates. These findings support a reproducible anatomical strategy to optimize safety in both routine and complex endocrine neck procedures.