Protection of parathyroid function during thyroid surgery with a complete intermediate approach: a retrospective multicenter observational study.

Background: Iatrogenic injury of the parathyroid gland during thyroid surgery cannot be completely avoided. The lateral approach is the most commonly used surgical approach in traditional thyroid surgery, whereas the complete intermediate approach has become common in endoscopic surgery and has been applied in traditional open surgery. In this study, the primary aim was to compare the effects of two surgical approaches on postoperative parathyroid function.

Methods: This study enrolled and analyzed 270 patients with papillary thyroid cancer. The patients underwent total thyroidectomy between January 2020 and December 2022 at three medical centers and were confirmed to have papillary thyroid cancer by paraffin pathology. All the patients were diagnosed by pathologists on the basis of preoperative and postoperative specimens. The sex, age, tumor diameter, lymphatic dissection range, operation time, preoperative parathyroid hormone level, parathyroid hormone level during follow-up, etc., were analyzed. Parathyroid function was monitored at 6 months after the surgery to identify hypoparathyroidism as permanent.

Results: The enrolled patients were divided into two groups: the complete intermediate approach surgical protocol group (the observation group) and the traditional thyroid surgery protocol group (the control group). There was no significant difference in preoperative blood parathyroid hormone levels or serum calcium levels between the observation group and the control group. However, the blood parathyroid hormone levels and blood calcium levels in the observation group were significantly greater than those in the control group on the first day after surgery. During the follow-up, these levels in all the patients in the observation group returned to the normal range, whereas four patients in the control group still exhibited decreased parathyroid hormone levels at the three-month and six-month follow-up, and thus was diagnosed as permament hypoparathyroidism.

Conclusion: Compared with the traditional lateral approach, the complete intermediate approach better protects parathyroid function and reduces the incidence of iatrogenic parathyroid injury.