Objective: To study the recovery in phonation after reconstruction of the recurrent laryngeal nerve (RLN) in patients whose thyroid cancer was invading the nerve, and to evaluate the role of ansa cervicalis to RLN anastomosis (ARA) in operations for thyroid cancer.
Design: Retrospective study.
Setting: University hospital and private thyroid clinic hospital, Japan.
Subjects: 34 patients with thyroid cancer who underwent reconstruction of unilateral RLN and 331 consecutive patients operated on for thyroid cancer.
Interventions: Reconstruction was direct anastomosis (DA), free nerve grafting (FNG), vagus-RLN anastomosis (VRA) or ARA, including anastomosis behind the thyroid cartilage.
Main outcome measures: Maximum phonation time (34 normal subjects and 26 patients with vocal cord paralysis served as controls), laryngoscopic examination, and the ratio of reconstruction in patients who needed resection of the RLN.
Results: The maximum phonation time started to increase rapidly 2-5 months postoperatively in most cases as the patients' voices recovered, and 12 months after reconstruction was significantly longer than in those patients with vocal cord paralysis (P < 0.0001). It was comparable to that of the normal subjects, although the reinnervated cords were fixed in the median. The number of reconstructions in the series of 331 patients increased from 18% to 82% after we started doing ARA with the meticulous technique of anastomosis inside the thyroid cartilage.
Conclusions: ARA is as effective as DA or FNG in improving phonation in patients who need resection of a unilateral RLN. As ARA has several advantages over FNG it has a definite place in operations for thyroid cancer.