Two trajectories of functional recovery in thyroid surgery related unilateral vocal cord paralysis

Advances in the assessment of cosmetic outcomes, sensory alteration in surgical areas, and health-related quality of life of endoscopic thyroidectomy

BACKGROUND

Endoscopic thyroidectomy has been preliminarily proven effective and safe for thyroid diseases. The cosmetic outcomes and life quality are critical contents of postoperative assessment. This review will primarily focus on the assessment methods and results related to cosmetic outcomes, sensory alteration of surgical area, and quality of life following endoscopic thyroidectomy.

METHODS

A comprehensive search of published articles within the last decade was conducted using the terms "endoscopic/robotic thyroidectomy," "patient satisfaction scores," "questionnaire," "quality of life," and "cosmetic" in PubMed.

RESULTS

Assessment methods for postoperative cosmetic satisfaction and sensory alterations encompassed verbal/visual analog scales, scar evaluations, Semmes-Weinstein monofilament tests, and more. The evaluation of postoperative quality of life in endoscopic thyroidectomy involved tools such as SF-36, SF-12, thyroid-specific questionnaires, thyroid cancer-specific quality of life questionnaires (THYCA-QOL), as well as assessments related to voice and swallow function. The cosmetic results of endoscopic thyroidectomy generally surpassed those of open thyroidectomy, while the quality of life in endoscopic procedures was either superior or equivalent to that in open thyroidectomy, especially with respect to general health, role emotion, and vitality.

CONCLUSIONS

Assessments of cosmetic outcomes and sensory alterations following endoscopic thyroidectomy predominantly relied on patients' subjective feelings. The objective and subjective perspectives of scar assessments remain underutilized. In addition, postoperative laryngoscopy and voice function assessments in endoscopic thyroidectomy procedures require more attention.

Pathophysiological Mechanisms Underlying Unilateral Vocal Fold Paralysis in Female Patients: An Ultrasonographic Study

OBJECTIVES

Laryngeal ultrasonography (LUS) has been suggested as an alternative diagnostic tool for unilateral vocal fold paralysis (UVFP). The present study applied LUS and quantitative laryngeal electromyography (LEMG) in female UVFP patients to investigate the pathophysiologic mechanisms of UVFP.

METHODS

In this cross-sectional study, vocal fold (VF) length parameters included resting and phonating VF length measured using B-mode LUS, and color Doppler vibrating length (CDVL) measured using the color Doppler mode.

RESULTS

Forty female patients with UVFP were enrolled, among whom 11 and 29 were assigned to the thyroarytenoid (TA) muscle+cricothyroid (CT) muscle group (with CT involvement) and the TA (without CT involvement) group, respectively. In the TA group, the turn frequency in thyroarytenoid-lateral cricoarytenoid (TA-LCA) on the paralyzed side, as observed through LEMG, correlated with the VF length during the resting phase (R=0.368, P=0.050) and CDVL values (R=0.627, P=0.000) on the paralyzed side. In the TA+CT group, the turn ratio in the CT muscle correlated with the normalized phonatory vocal length change (nPLC; R=0.621, P=0.041) on the paralyzed side.

CONCLUSION

CDVL and nPLC are two parameters that can be utilized to predict the turn frequencies of TA-LCA in UVFP cases without CT involvement, and the turn ratio of CT in cases of UVFP with CT involvement, respectively. The findings suggest that LUS, as a noninvasive tool, can serve as an alternative method for assessing the severity of laryngeal nerve injury and offer valuable insights into the pathophysiology of UVFP.

Is There Any Reliable Predictor of Functional Recovery Following Post-thyroidectomy Vocal Fold Paralysis?

BACKGROUND

Predicting definitive outcomes of post-thyroidectomy vocal fold paralysis (VFP) is challenging. We aimed to identify reliable predictors based on intraoperative neuromonitoring (IONM) and flexible fiberoptic laryngostroboscopy (FFL) findings.

METHODS

Among 1172 thyroid operations performed from April to December 2021, all patients who exhibited vocal fold paralysis (VFP) at post-operative laryngoscopy were included. IONM data, including type of loss of signal (LOS), were collected. Patients underwent FFL, with arytenoid motility assessment, at 15, 45 and 120 days post-operatively. Patients were divided into two groups: those who recovered vocal fold motility (VFM) by the 120th post-operative day (recovery group) and those who did not (non-recovery group).

RESULTS

Fifty-nine VFP cases (5.0% of total patients) met the inclusion criteria. Eight patients were lost at follow-up and were excluded. Overall, 9 patients were included in the non-recovery group (0.8% of total patients) and 42 in the recovery group. Among various predictive factors, only arytenoid fixation (AF) at the 15th post-operative day and Type I LOS were significant predictors for no VFM recovery (p = 0.007, RR = 9.739, CI:1.3-72.3 and p = 0.001, RR = 9.25, CI:2.2-39.3 for AF and Type I injury, respectively). The combination of type of LOS and arytenoid motility at the 15th post-op day yielded satisfactory predictive values for the progression of transient VFP to permanent.

CONCLUSIONS

Arytenoid motility at the 15th post-op day and type II LOS are associated with recovery of VFM. Type of LOS and FFL could be included in the follow-up protocols of patients with VFP to reliably predict clinical outcomes.