Role of immediate recurrent laryngeal nerve reconstruction in surgery for thyroid cancers with fixed vocal cords

Artificial Nerve Conduit for Recurrent Laryngeal Nerve Reconstruction in Thyroid Surgery

OBJECTIVE

Oncological reconstruction of the recurrent laryngeal nerve (RLN) is sometimes necessary for RLN invaded by thyroid cancer. There have been no case reports of RLN reconstruction using artificial nerve conduits, which are often used for peripheral nerves. In this study, we retrospectively evaluate the feasibility, safety, and efficacy of a collagen conduit with collagen filaments for RLN reconstruction cases at our hospital.

METHODS

Artificial nerve conduits were used in seven cases of RLN reconstruction. Two patients had preoperative unilateral vocal cord paralysis with severe vocal cord atrophy, and two had vocal cord paresis without atrophy. The remaining three patients had functional vocal cords before surgery that had to be resected via surgery due to thyroid cancer infiltration of the RLN. Reconstruction was performed using RENERVE®, which is a collagen conduit. Voice examination and laryngeal endoscopy were performed 1, 3, and 12 months after surgery.

RESULTS

There was no improvement in the phonetics of the two patients with vocal cord atrophy before surgery. In the remaining five cases, three with functional vocal cords improved to preoperative values, and two with vocal cord paresis improved to greater than preoperative values.

CONCLUSION

We report the first case series using an artificial nerve conduit for human RLN reconstruction. In cases of RLN resection when the patient has good voice quality pre-operatively, reconstruction of the RLN using an artificial nerve may be a favorable option in cases where direct anastomosis or ansa cervicalis to RLN anastomosis cannot be performed.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 2023.

The Role of Primary Repair of the Recurrent Laryngeal Nerve during Thyroid/Parathyroid Surgery in Vocal Outcomes-A Systematic Review

Recurrent laryngeal nerve (RLN) injury is a well and long-known complication of thyroid and parathyroid surgery that significantly affects the quality of life of patients. Despite the advances in surgical techniques and technology, it still occurs in clinical practice either as temporary paresis or as permanent paralysis of the corresponding vocal cord. The purpose of the current systematic review is to examine the value of intraoperative repair of the RLN in voice restoration. A systematic review of the existing literature was conducted using PubMed, Scopus, Cochrane Library, and Google Scholar databases according to the PRISMA guidelines. The systematic review resulted in 18 studies, which met the inclusion criteria. An improvement in phonatory function and voice quality was observed in all these studies after immediate RLN reconstruction (not always statistically significant). This improvement appears to be comparable to or even higher than that achieved with other methods of repair, and in some cases, the improvement approaches levels found in normal subjects. Intraoperative RLN reconstruction is not widely used in clinical practice, but the evidence so far makes it a viable and safe alternative to traditional techniques with better long-term results, as it prevents the occurrence of atrophy of the vocal cord and should be considered in the operating room if possible.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Timing of Ansa Cervicalis-to-recurrent Laryngeal Nerve Reinnervation: A Systematic Review

BACKGROUND

Ansa cervicalis-to-recurrent laryngeal nerve anastomosis (ARA) is an established technique for the treatment of recurrent laryngeal nerve (RLN) injury after head and neck surgery. However, the optimal timing of ARA remains unclear, and the evidence bases for ARA performed at each timepoint after RLN injury have not previously been clearly distinguished. We conducted a systematic review of the literature to evaluate the efficacy of ARA performed at different timepoints on postoperative voice outcomes.

METHODS

A review of English-language journal articles published in the last 20 years was undertaken on three electronic databases: Ovid MEDLINE, PubMed and Embase. Studies with a focus on paediatric RLN injury, bilateral RLN injury, ansa cervicalis anatomy and non-ARA techniques alone were excluded.

RESULTS

Twenty eight articles were included in the review. ARA was performed as a delayed surgery in 16/28 studies (57%), while immediate ARA was utilized in 14/28 studies (50%). On qualitative synthesis, delayed ARA was shown to be effective in improving patient-reported, subjective observer-reported and objective observer-reported voice outcomes. Likewise, a substantial body of evidence was identified demonstrating postoperative voice improvement with immediate ARA. On direct comparison of timepoints, some benefit was shown for early delayed ARA relative to late delayed operations, while no comparative data for immediate versus delayed repair were available in the literature.

CONCLUSIONS

ARA at both delayed and immediate timepoints is effective in the treatment of patients with RLN injury after head and neck surgery. The timing of ARA may have some influence on its efficacy, with early delayed repair potentially associated with superior outcomes to late delayed operations, and immediate ARA offering several practical advantages relative to delayed repair. Further comparative studies are required to better characterize the optimal timing of ARA after RLN injury.

Recurrent Laryngeal Nerve Paralysis Following Thyroidectomy: Analysis of Factors Affecting Nerve Recovery

OBJECTIVES

Paralysis of the recurrent laryngeal nerves (RLNs), albeit decreased over the years, leaves the surgeon helpless as there is not much that can be done once it occurs. Nimodipine has been suggested as a remedy that could accelerate the recovery of the nerve. Our study aimed to examine the factors that affect the recovery rate (RR) and time to recovery (TTR) of post-thyroidectomy RLN paralysis, with an emphasis on the use of nimodipine.

METHODS

A total of 197 patients who had undergone thyroid and parathyroid surgeries were retrospectively reviewed from October 2016 to August 2019. Patients who had RLN paralysis following surgery were assessed. The medical records were retrospectively analyzed to look for possible factors that may influence RLN recovery.

RESULTS

A total of 289 nerves were at risk. Temporary RLN paralysis rate was 7.9% while 1.7% was permanent. Age (odds ratio [OR] = 4.8) and intra-operative extra-thyroid extension (OR = 9.0) were independent risk factors for RLN paralysis. The rate of recovery was 82.1%. Loss of signal (LOS; P = .066) was a factor trending for an impact on RR but not nimodipine (P > .05). The mean TTR was 32 days. LOS, nimodipine, and steroid use, among others, were factors trending for an impact on the TTR.

CONCLUSION

Although not reaching statistical significance, nimodipine and steroids might influence TTR but not the RR. Larger studies are warranted to address the effect of nimodipine on the outcome of RLN paralysis.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

A novel method to reconstruct right recurrent laryngeal nerve by transforming into nonrecurrent laryngeal nerve: The end-to-free vagal laryngeal branch end anastomosis

The objective of this study is to demonstrate a novel method for the reconstruction of right recurrent laryngeal nerve (RLN) by transforming into nonrecurrent RLN: the end-to-free vagal laryngeal branch end anastomosis. Here we report a case of locally advanced thyroid carcinoma. The patient underwent radical thyroid surgery with inevitably partial RLN resection and immediate right RLN reconstruction at our institution. With the guidance of intraoperative neuromonitoring (IOMN), we completed a novel end-to-free vagal laryngeal branch end anastomosis. The whole procedure was deliberately monitored by IOMN. Surgeons can procure adequate free nerve for tension-free anastomosis by transforming the right RLN into nonrecurrent nerve. Follow-up laryngoscope showed improved adductory movement of the right arytenoid. The end-to-free vagal end anastomosis is an effective way to reconstruct segmental nerve resection of right RLN. Its long-term postoperative result needs to be further warranted.

Care and Management of Voice Change for Thyroid Surgery: Korean Society of Laryngology, Phoniatrics and Logopedics Clinical Practice Guideline

Voice change is a common complaint after thyroid surgery and has significant impacts on quality of life. The Korean Society of Laryngology, Phoniatrics, and Logopedics set up a task force team to establish guideline recommendations on education, care, and management related to thyroid surgery. The guideline recommendations include preoperative voice education, management of anticipated voice change during surgery, and comprehensive voice care after thyroid surgery, including in-depth information and up-to-date knowledge based on validated literature. The committee constructed 14 key questions (KQ) in three categories: preoperative (KQ1-2), intraoperative (KQ 3-8), and postoperative (KQ 9-14) management and developed 18 evidence-based recommendations. The Delphi survey reached an agreement on each recommendation. Detailed evidence profiles are presented for each recommendation. The level of evidence for each recommendation is classified into high, moderate, and low-quality. The recommendation's strengths are adjusted to consider the level of evidence resulting in the recommendation and are divided into strong and weak. The guidelines are primarily targeted toward physicians who treat thyroid surgery patients and speech-language pathologists participating in patient care. These guidelines will also help primary care physicians, nurses, healthcare policymakers, and patients improve their understanding of voice changes and voice care after thyroid surgery.

Optimal Management of the Unilateral Recurrent Laryngeal Nerve Involvement in Patients with Thyroid Cancer

Simple Summary

Recurrent laryngeal nerve (RLN) is the second most common structure invaded by primary or metastatic thyroid cancer. However, little is known about the optimal procedure for maintaining vocal function in patients with unilateral RLN involvement in thyroid cancer. This study aimed to evaluate various parameters of vocal function to establish the optimal management of thyroid cancer patients with unilateral RLN involvement. Based on our findings, we propose that for optimal management of unilateral RLN involvement in thyroid cancer, first, sharp dissection should be performed, and if this is impossible, a simultaneous RLN reconstruction procedure should be adopted whenever possible. These findings may help improve management of RLN involvement in patients with thyroid cancer and ensure vocal function preservation.

Abstract

We aimed to determine the optimal management of recurrent laryngeal nerve (RLN) involvement in thyroid cancer. We enrolled 80 patients with unilateral RLN involvement in thyroid cancer between 2000 and 2016. Eleven patients with preoperatively functional vocal folds (VFs) underwent sharp tumor resection to preserve the RLN (shaving group). Thirty-three patients underwent RLN reconstruction with RLN resection (reconstruction group). We divided the reconstruction group into two subgroups based on preoperative VF mobility (normal-reconstruction and paralyzed-reconstruction subgroups). In the cases where RLN reconstruction was difficult, phonosurgeries including arytenoid adduction (AA), with or without thyroplasty type I, or nerve muscle pedicle implantation with AA were performed later (phonosurgery group). We evaluated and compared vocal function among the evaluated periods and different groups. Postoperative vocal function in the shaving and normal-reconstruction subgroups was favorable. There were no significant differences between the two groups. In the paralyzed-reconstruction and phonosurgery groups, postoperative vocal function was significantly improved, and vocal function in the paralyzed-reconstruction subgroup was significantly better than that in the phonosurgery group. For optimal management of unilateral RLN involvement in thyroid cancer, first, sharp dissection should be performed, and if this is impossible, a simultaneous RLN reconstruction procedure should be adopted whenever possible.

Immediate Intraoperative Repair of the Recurrent Laryngeal Nerve in Thyroid Surgery

OBJECTIVES

Recurrent laryngeal nerve (RLN) injury is a recognized risk during thyroid and parathyroid surgery and can result in significant morbidity. The aim of this review paper is to consider the optimal approach to the immediate intraoperative repair of the RLN during thyroid surgery.

METHODS

A PubMed literature search was performed from inception to June 2020 using the following search strategy: immediate repair or repair recurrent laryngeal nerve, repair or reinnervation recurrent laryngeal nerve and immediate neurorraphy or neurorraphy recurrent laryngeal nerve.

RESULTS

Methods of immediate intraoperative repair of the RLN include direct end-to-end anastomosis, free nerve graft anastomosis, ansa cervicalis to RLN anastomosis, vagus to RLN anastomosis, and primary interposition graft. Techniques of nerve repair include micro-suturing, use of fibrin glue, and nerve grafting. Direct micro-suture is preferable when the defect can be repaired without tension. Fibrin glue has also been proposed for nerve repair but has been criticized for its toxicity, excessive slow reabsorption, and the risk of inflammatory reaction in the peripheral tissues. When the proximal stump of the RLN cannot be used, grafting could be done using transverse cervical nerve, supraclavicular nerve, vagus nerve, or ansa cervicalis.

CONCLUSIONS

Current evidence is low-level; however, it suggests that when the RLN has been severed, avulsed, or sacrificed during thyroid surgery it should be repaired intraoperatively. The immediate repair has on balance more advantages than disadvantages and should be considered whenever possible. This should enable the maintenance of vocal cord tone, better and prompter voice recovery and avoidance of aspiration. Laryngoscope, 131:1429-1435, 2021.

Immediate Ansa Cervicalis-to-Recurrent Laryngeal Nerve Anastomosis for the Management of Recurrent Laryngeal Nerve Infiltration by a Differentiated Thyroid Carcinoma

OBJECTIVES

The optimal surgical approach to treat recurrent laryngeal nerve (RLN) infiltration by differentiated thyroid cancer (DTC) remains a subject of debate. This study explored the feasibility and efficiency of immediate ansa cervicalis nerve (ACN)-to-RLN anastomosis for the management of RLN infiltration by DTC.

MATERIAL AND METHODS

Fifty-three patients who underwent immediate ACN-to-RLN anastomosis during DTC extirpation were enrolled in the present study. Thirty-seven cases presented with unilateral vocal cord paralysis before the operation (Group A), and another 16 patients presented with normal vocal cord mobility preoperatively (Group B). Multidimensional assessments, videostroboscopy, voice assessment, and laryngeal electromyography (LEMG) were performed preoperatively and postoperatively.

RESULTS

All videostroboscopy, voice assessment and LEMG parameters in Group A deteriorated 1 month after the operation and improved 1 year after the operation compared with preoperative data. In Group B, all parameters 1 year after the operation improved significantly compared with the corresponding parameters 1 month after the operation. LEMG in Group A and B provided substantial evidence for the maturation of neural regeneration from ACN and demonstrated that the laryngeal muscles were reinnervated successfully by this procedure.

CONCLUSIONS

If the RLN is infiltrated by DTC, immediate ACN-to-RLN anastomosis during complete excision of DTC could restore satisfactory phonatory function and does not compromise oncological radicality.