Endocrine Abstracts

Background: Hypoparathyroidism is one of the most important complications of total thyroidectomy. Its treatment with the use of recombinant parathyroid hormone (PTH) is limited now, therefore the prophylaxis of post-surgical hypoparathyroidism is very important. A method of tension-free thyroidectomy (TFT) was proposed in 2021. TFT uses unusual medial approach to the recurrent laryngeal nerves (RLN) and parathyroid glands (PG), together with several principles decreasing traction applied by the surgeon to these anatomical structures.

Method: 117 consecutive patients underwent total thyroidectomy with the use of TFT technique (there were 468 PGs at risk). In 46 (39.3%) cases patients additionally underwent central neck dissection with preservation of the thymus horns and their blood supply, in 13 cases–lateral neck dissection. Indications for surgery were thyroid cancer (n=56; 47.9%), follicular neoplasia (n=25; 21.4%), Grave’s disease (n=27; 23.1%), nodular toxic goiter (n=7; 5.9%), nodular nontoxic goiter (n=2; 1.7%). Mean thyroid volume was 69 ml (±58 ml). Mean diameter of the thyroid nodule was 42 mm (±64 mm). Intraoperative neuromonitoring was used in all the cases (5 mV). Calcium and PTH levels were measured on the day of surgery and on the day 1. In cases where PTH level dropped, additional calcium and PTH tests were performed on the 14th, 30th, 90th postoperative days. Laryngoscopy was used in all the cases prior and after surgery to evaluate vocal folds mobility.

Results: Unintentional complete PG removal occurred in 1 case (0.2% of PGs at risk), a fragment of parathyroid tissue was unintentionally removed in 14 cases (3.0% of PGs at risk). Hypoparathyroidism occurred in 12 patients (10.2%). In 7 out of these patients PTH level started to rise on the first postoperative day. In all the cases PG function has restored in the next 90 days, thus the rate of permanent hypoparathyroidism was 0%. Only in 2 cases hypoparathyroidism occurred in patients with unintentionally removed PG fragments, which means that the main reason for hypoparathyroidism was ischemia. An additional benefit of TFT was the low rate of RLN palsy which was registered in 2 cases (unilateral palsy; 0.9% of 234 RLNs at risk). In both cases RLN function restored, therefore the rate of permanent RLN palsy was 0%.

Conclusion: This initial study shows that TFT gives an opportunity to achieve the low rate of permanent complications such as hypoparathyroidism and RLN palsy.