Background: We reported phonatory recovery in the majority of 88 patients after recurrent laryngeal nerve (RLN) reconstruction. Here we analyzed factors that might influence the recovery, in a larger patient series.
Methods: At Kuma Hospital, 449 patients (354 females and 95 males) underwent RLN reconstruction with direct anastomosis, ansa cervicalis-to-RLN anastomosis, free nerve grafting, or vagus-to-RLN anastomosis; 47.4 % had vocal cord paralysis (VCP) preoperatively. Maximum phonation time (MPT) and mean airflow rate during phonation (MFR) were measured 1 year post surgery. Forty patients whose unilateral RLNs were resected and not reconstructed and 1257 normal subjects served as controls.
Results: Compared to the VCP patients, the RLN reconstruction patients had significantly longer MPTs 1 year after surgery, nearing the normal values. The MFR results were similar but less clear. Detailed analyses of 228 female patients with reconstruction for whom data were available revealed that none of the following factors significantly affected phonatory recovery: age, preoperative VCP, method of reconstruction, site of distal anastomosis, use of magnifier, thickness of suture thread, and experience of surgeon. Of these 228 patients, 24 (10.5 %) had MPTs <9 s 1 year after surgery, indicating insufficient recovery in phonation. This insufficiency was also not associated with the factors mentioned above.
Conclusions: Approximately 90 % of patients who needed resection of the RLN achieved phonatory recovery following RLN reconstruction. The recovery was not associated with gender, age, preoperative VCP, surgical method of reconstruction, or experience of the surgeon. Performing reconstruction during thyroid surgery is essential whenever the RLN is resected.