D. S. Kim1, A. E. Barber1, R. C. Wang1 1University Of Nevada School Of Medicine,Department Of Surgery,Las Vegas, NV, USA
Introduction:
Hypocalcemia is the most common early postoperative complication of total thyroidectomy, with reported incidences up to 50% in some series, due to injury to or removal of parathyroid glands and/or compromise of parathyroid vascular supply. After observing an incidence of 20% transient hypocalcemia in our previous series, we adopted systematic changes in surgical technique in order to decrease postoperative hypocalcemia without routine calcium supplementation.
Methods:
This was a prospective cohort study with chart review. 145 consecutive patients undergoing either total or completion thyroidectomy with or without central neck dissection at a tertiary academic center and a community hospital between May 2013 and June 2016 were included. Initial 70 patients underwent total thyroidectomy using standard techniques. Total thyroidectomy using a modified technique was performed on the subsequent 75 patients. This systematic approach consisted of the following sequential steps: mobilization of the medial and inferior thyroid lobe from the trachea to displace the inferior lobe away from the recurrent laryngeal nerve (RLN), exposure and transection of the attachments of the inferior parathyroid gland to the thyroid gland without compromising its blood supply from the inferior thyroid vessels, exposure of the RLN superiorly followed by completion of mobilization of the thyroid from the trachea and larynx, displacement of the thyroid lobe medially and inferiorly, exposure and transection of the attachments of the superior parathyroid gland to the thyroid gland without compromising the blood supply from either the superior or inferior thyroid vessels, and ligation of terminal superior thyroid vessels on one side and then on the contralateral side. Blunt, blade shaped instruments instead of hemostats were used to dissect around the small parathyroid vessels. Harmonic scissors were used in all patients instead of ligatures whenever feasible. All patients were observed overnight without routine calcium supplementation. Significant biochemical hypocalcemia was defined as total serum Ca < 7.6 mg/dL 12 hours after surgery. Parathyroid hormone was measured in the preoperative, intraoperative and postoperative periods.
Results:
In the standard technique group, 14 of 70 patients (20.0%) developed transient hypocalcemia while 2 patients (2.9%) developed permanent hypoparathyroidism. Following the implementation of the new techniques, the incidence of transient hypocalcemia decreased to 2.7% (n=2/75; χ2=11.1, p<0.001), and there was no incidence of permanent hypoparathyroidism or hypocalcemia. No case of postoperative vocal cord palsy or paralysis was noted in both groups. The durations of surgeries were not significantly different between the two groups.
Conclusion:
The modified thyroidectomy techniques presented in this study improved the preservation of parathyroid gland function and reduced the incidence of postoperative hypocalcemia significantly.