Post-thyroidectomy Vocal Cord Paralysis Along With Hypocalcemia: STROBE - Guided Prospective Cohort

Overview

In the present study, the severity of recurrent laryngeal nerve injury (RLNI) and hypocalcemia (H) will be followed-up and the probable interrelation between them will be proposed considering the clinical situation of patients, e.g. improvement in hypocalcemia also make a positive effect on voice? (any objective sign? Ca? PTH?), return of voice is parallel with the improvement in hypocalcemia? Postoperative calcium (Ca), parathyroid hormone (PTH), regular vocal cord evaluations by ear-nose-throat (ENT) exams, deterioration-stability-improvement of clinical symptoms regarding both Ca metabolism and vocal cord function will be noted at regular intervals (postoperative day 1-3-first, weekly control/first month, monthly/first 6-month, 3-monthly/6-12 months) at outpatient controls. Serum Ca, PTH, ENT evaluation of vocal cords-noted.

Total thyroidectomy is currently the preferred surgical treatment modality for both thyroid carcinomas and benign disorders such as multinodular goitre, since it minimizes the risk of recurrence and eliminates the complication risks of repeat or completion surgery. Vocal cord paralysis due to injury to recurrent laryngeal nerve (RLN) is the most dreaded complication of total thyroidectomy. The reported incidence of temporary RLN injury (RLNI) varies between 0 and 12 %, while the incidence of permanent RLNI has been reported to be much lower (0-3.5 %). In case of bilateral RLNI, respiratory distress and aspiration can develop rapidly and may result in mortality. Therefore, all precautions including close monitoring and tracheostomy should be undertaken without any delay. The best known technique to avoid injury to RLN is meticulous dissection of the nerve throughout its anatomic pathway. However, functional impairment of RLN is not visible macroscopically and intraoperative nerve monitoring (IONM) has been developed to monitor the nerve to avoid unnecessary dissection. Meticulous hemostasis can be achieved with harmonic sealing instrument, since improper hemostasis is known to increase the risk of RLNI. Despite the lack of evidence to support an advantage of IONM over the standard anatomic dissection of RLN, surgeons have adopted it in increasing ratios. The second most feared compliation of thyroidectomy is iatrogenic hypocalcemia. Transient symptomatic hypocalcemia after total thyroidectomy occurs in approximately 7% to 25% of cases, but permanent hypocalcemia is less common (0.4% to 13.8%). Size and invasion of tumor, operative trauma and vascular compromise determines the severity of symptoms.