Selective Reinnervation Research Articles

Functional Outcome of single-stage facial reanimation surgery with radical parotidectomy.

Facial nerve sacrifice during radical parotidectomy impairs quality of life. This study assessed the effectiveness of simultaneous single-stage facial reanimation surgery with radical parotidectomy in restoring facial function. A retrospective analysis was conducted on patients who underwent single-stage facial reanimation with radical parotidectomy. Techniques included selective reinnervation and orthodromic temporalis tendon transfer. Outcomes were measured using modified House-Brackmann and Terzis grades, Emotrics facial assessment, and the Facial Disability Index (FDI). Among thirteen patients (median age 54, 69% male), ten received selective reinnervation. Nine of these patients showed improved results of House-Brackmann grade III and Terzis grade 4-5. The remaining three underwent tendon transfer, achieving moderate functional outcomes. Emotrics analysis indicated balanced facial symmetry in the selective reinnervation group. FDI scores reflected satisfactory physical and social/well-being functions. Single-stage facial reanimation effectively restores facial function in patients undergoing radical parotidectomy. This approach offers significant benefits in early facial function recovery.

양측 성대 마비의 치료

Laryngeal reinnervation has been investigated as a treatment option for bilateral vocal fold paralysis (BVFP) that can restore laryngeal function while preserving laryngeal anatomy. Traditionally, BVFP treatment involves irreversible structural changes to the larynx, such as tracheostomy, arytenoidectomy, or cordectomy, which often result in impaired voice and swallowing. In contrast, laryngeal reinnervation aims to restore laryngeal muscle tone and function by providing new neural input to the paralyzed larynx. Reinnervation techniques can be broadly categorized into non-selective and selective methods. Non-selective reinnervation, such as recurrent laryngeal nerve (RLN) end-to-end anastomosis or ansa cervicalis-to-RLN anastomosis, primarily focuses on maintaining muscle bulk and tone. Selective reinnervation techniques, including nerve-muscle pedicle with the ansa cervicalis, selective reinnervation using the phrenic nerve, and bilateral selective laryngeal reinnervation, aim to restore both abduction and adduction function of the larynx. This review summarizes the current laryngeal reinnervation techniques for BVFP treatment.

Management of Pediatric Bilateral Vocal Fold Paralysis: A State-of-the-Art Review of Etiologies, Diagnosis, and Treatments.

This paper reviews the current literature about epidemiology, etiologies, diagnosis, and management of pediatric bilateral vocal fold paralysis (PBVFP). According to PRISMA statements, a narrative review of the current literature was conducted through the PubMed, Scopus, and Cochrane Library databases about the epidemiology, etiologies, diagnosis, and management of PBVFP. PBVCP is the second most common congenital laryngeal anomaly in the pediatric population, accounting for 10% to 20% of pediatric laryngeal conditions. PBVCP is related to idiopathic (42.2%), congenital (19.7%), and neurological (16.9%) conditions. A tracheotomy is required in 60% of cases regarding stridor and dyspnea, which are the most prevalent symptoms. The diagnosis is based on the etiological features, clinical presentation, laryngoscopic findings, and objective examinations. Laryngeal electromyography may be used to support the diagnosis in difficult cases, but its reliability depends on the practitioner's experience. The primary differential diagnosis is posterior glottis stenosis, which needs to be excluded regarding therapeutic and management differences with PBVCP. Transient surgical procedures consist of tracheotomy or laterofixation of the vocal fold. Current permanent procedures include uni- or bilateral partial arytenoidectomy, posterior transverse cordotomy, cricoid splits, and laryngeal selective reinnervation. There is no evidence of the superiority of some procedures over others. PBVCP is the second most common laryngeal disorder in the pediatric population. Diagnosis is based on etiological and clinical findings and may require the use of laryngeal electromyography. Therapeutic management may involve several transient or permanent surgical procedures that are associated with overall subjective improvements in symptoms, laryngeal findings, and low complication rates.

Early and delayed surgical management of the pronator teres syndrome. Selective reinnervation of the anterior interosseous nerve aimed to restore pinch grip among patients with late clinical presentation

Background. The incidence of pronator teres syndrome (PTS) is low. The misdiagnosis leads to delay in surgical treatment and irreversible changes not only within the median nerve (MN) itself, but within the sensory and muscular apparatus as well.Objective: to compare the outcomes of early and delayed surgical management of PTS; to compare the restoration of the pinch grip (PG) after decompression and reinnervation (nerve transfer, NT) of the anterior interosseous nerve (AIN) vs. decompression of MN alone in late terms of the disease (PTS).Materials and Methods. Six patients with verified PTS were included into the study. Three patients with the history of the disease (HoD) less than 3 mos. received surgical decompression (SD) of MN under standartized methodology alone. Another three patients with the HoD more than 3 mos. received SD of MN, with two of them received simultaneous NT of the branches of the radial or MN to AIN. In all patients sensory and motor deficit (function of "extrinsic"and "intrinsic"muscles), intensity of the neuropathic pain, both pre- and post-surgery have been evaluated according to MRC Scale and VAS, respectively. An ability to reproduce PG, or “OK” sign, with help of the thumb (flexor pollicis longus muscle – FPL) and index finger (deep flexor muscle – FDP2) were evaluated.Results. All patients showed complete relief of the neuropathic pain (VAS0) regardless of the terms of the disease. Three patients with HoD less than 3 mos. showed good recovery of FPL, FDP2 (M4-5) – all patients were able to reproduce "OK" sign. One patient with HoD more than 3 mos. after SD of MN alone showed no recovery of FPL, FDP2 (M0-1). Another two patients with the HoD more than 3 mos. showed good recovery of FPL and FDP2 (M3-4) after NT to AIN. No patient with HoD more than 3 mos. was able to reproduce "OK" sign.Conclusions. Early decompression of MN in PTS cases results in complete relief of the sensory and motor neurologic deficit; late decompression of MN in PTS cases does not lead to relief of the sensory deficit within NCP autonomous area, while the prognosis of the recovery of the median nerve innervated “extrinsic” and “intrinsic” muscles is rather unfavorable; In case of late PTS presentation, NT to AIN allows restoring only a single component ("extrinsics") of the motor functions of the hand which are required for the succesfull reproduction of the pinch grip; In case of late PTS presentation, poor recovery of OP should be expected, hence the succesfull reproduction of the pinch grip due to the thumb hyperadduction would be impossible; carefull interpretation of the clinical, radiological and electophysiological data on the pre-surgical stage could potentially help avoiding the misdiagnosis and improve the outcomes of the surgical treatment in all cases of a single or multilevel MN entrapment.

Selective surgical reinnervationn of the axillary nerve due to supraclavicular brachial plexus injury: outcomes of 42 consecutive cases, causes of inefficacy

Objective: retrospective analysis of the outcomes of selective surgical reinnervation (SSR) of the axillary nerve (Ax) in patients with supraclavicular brachial plexus injury (SBPI). Materials and methods. Forty-two patients (mean age 31.2 years) received 25 SSR with extraplexus donor nerves (e-ND) – 9 cases of subtotal SBPI and 16 cases of complete SBPI. In 17 cases of subtotal SBPI exclusively intraplexus donor nerve (i-ND) were utilized. Twenty-nine (69%) patients received SSR in terms up to 6 months, 13 patients (31%) – in terms more than 6 months. All patients at the time of inclusion were examined neurologically, electophisilogically and in 6, 9, 15 and 17 months. Recovery of the deltoid (D) muscle was assessed on Medical Research Council Scale (MRC Scale) – effective power (Еp). Recovery of effective function (Ef) has been assessed on the basis of flexion angle in glenohumeral joint in sagittal plane. Results. Ер of D recovered in 12 patients (28%), in terms up to 6 months - in 31%, more than 6 months – in 23%. Ep of D recovered after SSR with i-ND in 9 patients (52%), in terms up to than 6 months - in 60%, more than 6 months – in 43%. Ep of D recovered after SSR with e-ND in 3 patients (12%), in terms up to 6 months- in 16%, no recovery of Ep has been observed in terms more than 6months.Ef of D recovered in 11 patients (26%), in terms up to 6months - in 31%, more than 6months – in 15%. Ef of D recovered after SSR with i-ND in 8 patients (53%), in terms up to 6 months - in 60%, more than 6 months – in 29%. Ep of D recovered after SSR with e-ND in 3 cases (12%), in terms up to 6months - in 16%, no recovery of Ep has been observed in terms more than 6months. Recovery of Ef of D at subtotal SBPI occurred in 10 cases (38%), regardless of whether i-ND or e-ND have been utilized. SSR with e-ND at subtotal SBPI allowed restoring Ef of D in 2 cases (22%). SSR with i-ND at subtotal SBPI allowed restoring Ef of D in 8 cases (47%). SSR at complete SBPI allowed restoring Ef of D in 1 case (6%). Conclusions. e-ND can be utilized at complete SBPI in order to provide stability to glenohumeral joint in terms up to 6 months; i-ND should be utilized in all cases of subtotal SBPI in order to provide Ef to D in terms up to 6 months.

Surgical treatment of unilateral laryngeal paralysis by selective reinnervation in thyroid surgery

State of the problem: One of the complications in thyroid surgery is a lesion of RLN which can be bilateral with a violation of respiratory function of the larynx and unilateral, in which the first priority is a violation of vocal function of the larynx. The most effective treatment for paralysis of the larynx is the method of laryngeal reinnervation, which can be non-selective, which is usually used in unilateral laryngeal paralysis and promotes reinnervation of both abductors and laryngeal adductors. Selective reinnervation is selectively focuses on the reinnervation of individual target muscles, so it is more often used in bilateral laryngeal paralysis. But despite this, it was used in unilateral laryngeal paralysis during surgery on the thyroid gland during intentional resection of the anterior branch of RLN with partial invasion of its tumour process. Aim: evaluation of the results of surgical treatment unilateral laryngeal paralysis by the method selective reinnervation in thyroidectomy. Materials and Methods: clinical case results of patient A. 15 years old with papillary thyroid cancer and metastases to regional lymph nodes of the neck (T4aN1M0) with absence disorders of laryngeal motility before surgery were analyzed. Examination of the larynx and voice examination were performed before surgery, 2-3 days and 6,12 months after surgery. Changes of laryngoscopic images and evaluation of the Indicators: maximum pho- nation time, fundamental frequency, noise to harmonic ratio, Jitter (loc), Shimmer (loc), Voice Handicap Index-30 (VHI-30), completed version of Jacobcon B. Results: Considering extralaryngeal bifurcation of the recurrent laryngeal nerve (RLN) and invasion of the tumor into the adductive branch of RLN on the left, its dissection was performed and end-to-end neuroanastomosis was formed, completed is selective laryngeal reinnervation. In the immediate postoperative period, patients complained of voice disorders. Study of voice parameters corresponded to severe voice disorders. Partial resumption of the mobility of the larynx and voice function was after 6 months. The signs of the laryngoscopic picture and the spectral analysis of the voice corresponded to the indicators before the operation after 12 months Сonclusions 1. Primary selective reinnervation of the larynx can be used to treat unilateral laryngeal paralysis under the following conditions: extralaryngeal branching of the recurrent laryngeal nerve (bifurcation), lesion of only one of its branches, which will provide sufficient coaxiality to perform anastomosis "end-to-end" and preservation electrical integrity of another branch. 2. This method allows you to restore the motility of the denervated vocal folds and the main indicators of the voice. 3. Given only one clinical case of treatment of unilateral laryngeal paralysis by selective reinnervation, this technique needs further study and refinement.

Nerventranspositionen (Nerventransfers): Entwicklung und Prinzipien

This review article presents the history, indications and techniques for the usual nerve transpositions in the upper extremities. By means of nerve transposition paralyzed muscles are reinnervated using dispensable donor motor axons. Many standard operations on the upper extremities are attributable to concepts of German-speaking surgeons and orthopedists. The reliable return of function by the short-range and selective motor reinnervation using nerve transfer results in a renaissance of these techniques. The spectrum of applications has been substantially extended in recent years. In order to achieve an optimal result, a subtle microsurgical technique is necessary. In this way excellent results can be achieved even for complex proximal nerve injuries.

Selective laryngeal reinnervation for management of bilateral vocal cord paralysis

The surgical treatment of bilateral vocal fold paralysis should pro-vide patients with breathing comfort and adequate vocal function without the risk of foreign body aspiration. Bilateral selective la-ryngeal reinnervation appears to fulfill the above criteria while being an innovative method which opens up new horizons while not precluding the option of traditional static surgeries being car-ried out to expand the rima glottidis in cases of previous treatment failure. Proper selection of patients including detailed diagnostic tests is important for the success of the treatment. Selective rein-nervation of posterior cricoarytenoid muscles facilitates the ab-duction of vocal folds upon breathing. Reconstruction of the se-parate innervation of laryngeal muscles prevents the adduction of vocal folds upon inspiration while simultaneously preventing their atrophy and ensuring proper tension. Pulmonary function impro-vement is observed with good voice quality being maintained and no synkinesis being observed. However, selective laryngeal rein-nervation requires high precision and experience in the formation of microsurgical nerve anastomoses. Temporary tracheostomy is also required in patients. Transient aspiration may occur following the procedure and should be prevented. </br> </br> As seen from the cited studies, long-term follow-up results are favorable and bilateral selective laryngeal reinnervation should be included in the protocols for the management of patients with bilateral vocal fold paralysis.

Functional Outcomes Following Delayed Laryngeal Reinnervation Of Patients with Vagal Paralysis After Paraganglioma and Schwannoma Surgery

We present a prospective case series that aimed to report the functional (voice and swallowing) outcomes of delayed laryngeal reinnervation following vagal interruption by resection of vagal paraganglioma and schwannoma. A dedicated, anonymized database was established in 2012 with a minimum eighteen-month follow up set for this report. Internationally validated self- and observer-reported measures were recorded preoperatively and at six, 12 and, 18 months together with demographics, diagnoses, and operative details. A total of eight patients with a median age of 46 (37-54) underwent excision of vagal paraganglioma (five) and schwannoma (three) with few mild complications. Three underwent selective and five non selective reinnervation. Seven out of eight patients underwent synchronous injection medialization. The voice handicap index (VHI-30) improved from a baseline median 83 (range 52-102) to 7.5 (5-58) at 18 months; maximum phonation time improved from median 8 (range 5-15) to 10.5 (8.5-11); voice grade ("G" in grade, roughness, breathiness, asthenia, and strain [GRBAS] scoring) improved from median three (severe impairment, range 0-3) to one (mild impairment, 0-2); Eating Assessment Tool (EAT-10) score improved from median 12 (range 3.5-27) preoperatively to one (0-16); and reflux symptom index (RSI) improved from median 25 (range 17-36) to 7 (0-36). One patient exhibited no discernible reinnervation, while the remainder exhibited good cord bulk and tone, though without purposive abduction. Delayed laryngeal reinnervation for high vagal paralysis is a safe technique associated with good voice and swallowing outcomes by 12-18 months. Potential confounders in this small series and the absence of a control arm both limit conclusions, but this study suggests that further prospective, controlled studies, and/or case registration are merited.

Topographical, anatomical and neurosurgical aspects of "end-to-side" nerve repair

The article presents the results of a comprehensive anatomical and experimental study of individual variability in the structure and topography of motor branches of peripheral nerves in relation to the justification of methods for selective reinnervation of tissues by the "end-to-side" neurorrhaphy. It was found that relatively longer branches of peripheral nerves with a small number of connecting inter-arm collaterals characteristic of narrow and long limbs create conditions for less traumatic mobilization of motor branches. In cases with relatively wide and short extremities mobilization of peripheral nerves is complicated by the presence of a large number of collateral branches and intra-trunk connections, which are often damaged when separate bundles that make up the mobilized branches of the donor or recipient nerve are isolated from the main nerve trunk. It has been shown that potential recipient nerves should be motor branches of peripheral nerves, the preservation of which is of fundamental importance for the function of the corresponding segment of the limb. To create conditions conducive to selective reinnervation of functionally significant muscle groups of the upper limb, we have developed, justified from anatomical positions, and tested in an experiment on anatomical material methods for connecting the distal motor branches of peripheral nerves by the "end-to-side" neurorrhaphy. The main idea of accelerated recovery of the thumb opposition in injuries of the median nerve is to reinnervate the muscles of the elevation of the I finger due to nerve fibers that are part of the deep branch of the ulnar nerve. For this purpose, surgical techniques have been developed for connecting the recurrent motor branch of the damaged median nerve mobilized at the level of the wrist with the edges of a surgically formed perineurium defect on the lateral surface of the bundles that make up the deep branch of the ulnar nerve. In another clinical situation, in patients with radial nerve injuries, for the muscle reinnervation, а method is proposed for neurotisation of the deep motor branch of the radial nerve by the end-to-side suture to the lateral surface of the median nerve. We assume that performing the "end-to-side" nerve suture at the level of the base of the hand in the cases of proximal damage to the median nerve will reduce the time of reinnervation of the muscles of the thumb elevation by 400450 days. Transposition of the deep branch of the damaged at the proximal level radial nerve with "end-to-side" neurorrhaphy to the median nerve by 250300 days (based on the total length of the shoulder and forearm, which is about 50 cm and the rate of regeneration of nerve fibers 1 mm per day). Accordingly, with higher injuries (brachial plexus), the gain in the time of reinnervation of the distal segments will be even greater. In our opinion, the results can be used as a basis for further clinical research on the development of methods for selective tissue reinnervation in cases with isolated injuries of the peripheral nerves.

Anesthetic Management for Awake Tubeless Suspension Microlaryngoscopy.

Patients' eligibility for bilateral selective laryngeal reinnervation surgery is evaluated by suspension microlaryngoscopy (SML) examination with laryngeal electromyography (LEMG). Maintaining spontaneous ventilation, with remifentanil sedation/analgesia without endotracheal tube, to allow the patient to phonate with the surgeon during awake, LEMG is a major challenge for the anesthesiologist and the otorhinololaryngologist. The objective of this study was to evaluate the safety and efficacy of a novel anesthesia protocol to manage airway access during awake tubeless SML. Retrospective study. Anesthesia records of patients undergoing awake SML with LEMG were retrospectively analyzed. Procedures were performed with remifentanil sedation/analgesia with targeted controlled infusion (TCI) in combination with local anesthesia. The main outcome was the failure rate of the anesthesia protocol during the procedure. Secondary outcomes were as follows: rate of apnea requiring ventilation, airway bleeding, regurgitation, hemodynamic data as well as vasopressor use, complications, and surgeon satisfaction with the procedure. Data were obtained for 39 patients between November 2017 and September 2019, the mean age was 52 years and 29 (74%) were female. All procedures were completed without complications (0% [0-9]). Three patients (8% [1.6-20.8]) had an intraoperative episode of hypoxemia requiring mask reventilation. There was no airway bleeding, no regurgitation, and no hypotensive episode. Three patients (8% [1.6-20.8]) had noninvasive ventilation for respiratory distress after the end of the procedure. Our results show that awake tubeless SML allowing phonation during LEMG can be realized under sedation and local anesthesia. However, further data are needed concerning the intraoperative and postoperative safety of the procedure. 4 Laryngoscope, 131:E2669-E2675, 2021.

Clinical analysis of selective laryngeal reinnervation using upper root of phrenic nerve and hypoglossal nerve branch in the treatment of bilateral vocal fold paralysis

Objective: To evaluate the airway and voice quality improvement in patients with bilateral vocal fold paralysis (BVFP) who underwent selective laryngeal reinnervation surgery. Methods: From January 2012 to December 2016, a retrospective study was conducted in 39 patients with BVFP who underwent selective laryngeal reinnervation surgery in Department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of Navy Medical University. All patients were examined by videostroboscopy, vocal function assessment, laryngeal electromyography and pulmonary function test before and after the surgery, and followed up for at least 2 years to evaluate the efficacy and safety of the surgery.Wilcoxon signed rank test was used to analyze the G score and VHI-10 score data. Paired t-test was used to analyze acoustic parameters, MPT values and pulmonary function parameters. Results: Postoperative infection and hemorrhage occurred in one patient separately.Videostroboscopic videos showed that at 4-8 months postoperatively, vocal folds in 35 patients achieved moderate or severe abduction during inspiration, 2 patients only achieved mild abduction, 2 patients showed no abduction,while all patients achieved adduction in bilateral vocal cords during phonation. The recovery rate of moderate-to-severe abduction was 89.7% (35/39), and these patients were decannulated successfully. At 12 months after operation, G score and VHI-10 score were significantly lower than those before operation (P<0.05), and the acoustic parameters jitter, shimmer, HNR and MPT were significantly improved (P<0.05). Most of the parameters of the pulmonary function test at 3 months postoperatively returned to the normal reference level, while the maximum inspiratory pressure (PImax) at 12 months after operation was still slightly lower than the normal level, but it was significantly improved compared with preoperative value (P<0.05). The EMG data at 12 months postoperatively showed full interference potentials in 37 patients in bilateral posterior cricoarytenoid muscles during inspiration, and full interference potentials in bilateralthyroarytenoid muscles during phonation. Obvious misdirected regeneration electric activitieswere found in two of them. Potentials in posterior cricoarytenoid muscle were weak in 2 cases with poor abduction. During long-term follow-up, only one case showed decreased abduction, but did not affect respiratory function. Conclusions: The selective laryngeal reinnervation procedure applied in the present study can restore physiological motion of vocal cords. The success rate was high, the curative effect was stable, and the complications were rare. It is worth of promotion.

Surgical Considerations for Laryngeal Reinnervation and Future Research Directions

This paper examines the history, current use, and future directions of laryngeal reinnervation surgery. Nonselective laryngeal reinnervation has been refined as a surgical technique for use in unilateral vocal fold paralysis. Selective laryngeal reinnervation is a viable surgical option for bilateral vocal fold paralysis. The use of laryngeal pacing devices, nimodipine, stem cells, and manipulation of the cellular and chemical microenvironment are future areas of study for laryngeal reinnervation. While both thyroplasty and injection laryngoplasty are highly effective and remain the most popular treatment for unilateral vocal fold paralysis, nonselective laryngeal reinnervation offers several benefits that may help surgeons achieve superior results. Similarly, selective laryngeal reinnervation for treatment of bilateral vocal fold paralysis is a viable alternative to the life changing tracheostomy and potentially preserves laryngeal function better than iterations of posterior cordotomy surgery.

Bilateral Selective Laryngeal Reinnervation for Bilateral Vocal Fold Paralysis in Children

Bilateral vocal fold paralysis (BVFP) in pediatric patients is a challenging entity with multiple causes. Traditional approaches to managing BVFP include tracheostomy, arytenoidectomy, suture lateralization, cordotomy, and posterior cricoid enlargement. These interventions are used to create a stable airway but risk compromising voice quality. To assess the use of bilateral selective laryngeal reinnervation (SLR) surgery to manage BVFP and restore dynamic function to the larynx in pediatric patients. In this case series performed at 2 tertiary care academic institutions, 8 pediatric patients underwent bilateral SLR to treat BVFP (5 patients with iatrogenic BVFP and 3 with congenital BVFP) from November 2004 to August 2018 with follow-up for at least 1.5 years. Bilateral selective laryngeal reinnervation surgery. Flexible laryngoscopy findings, subjective and objective measures of voice quality, subjective swallowing function, and decannulation in patients who were previously dependent on a tracheostomy tube. Participants included 6 boys and 2 girls with a median age of 9.3 (range, 2.2 to 18.0) years at the time of surgery. All 8 patients were decannulated; 6 patients had preoperative tracheostomies and 2 had perioperative tracheostomies. Voice quality, as measured using the GRBAS (grade, roughness, breathiness, asthenia, strain) scale, improved in 6 of 8 patients after reinnervation, and swallowing was not impaired in any patients. In 2 patients, GRBAS scale scores remained the same before and after surgery. Inspiratory vocal fold abduction was observed on both sides in 5 patients and on 1 side in 2 patients, with no active abduction observed in 1 patient. The follow-up period was more than 5 years in 7 of 8 patients and at least 1.5 years in all patients. Bilateral SLR appears to be a promising treatment option for children with BVFP; it is currently the only option, to our knowledge, with the potential to restore abductor and adductor vocal fold movement. In patients with complete paralysis, this procedure may provide a strategy for airway management and restoration of the dynamic function of the larynx. It could be considered as a first-line technique before endolaryngeal or airway framework procedures, which carry a risk of compromising voice quality.

Assessment of bilateral vocal fold immobility prior to selective bilateral laryngeal reinnervation.

Assessment of bilateral vocal fold immobility prior to selective bilateral laryngeal reinnervation.

Laryngeal Reinnervation: The History and Where We Stand Now.

Injury to the recurrent laryngeal nerve (RLN) can result in impairment of all three laryngeal functions. The RLN is capable of regeneration, but laryngeal functions in cases of severe injury remain impaired. This permanent impairment is caused by either incomplete regeneration and/or occurrence of laryngeal synkinesis. Laryngeal reinnervation can be approached either nonselectively, focusing on nerve reconstruction, or selectively, focusing on separate target muscle reinnervation. Nonselective reinnervation comprises anastomosis to the mainstem of the RLN leading to reinnervation of both abductor and adductor muscle groups (nerve-based reconstruction). In selective reinnervation, abductor and/or adductor muscles are separately reinnervated (function-based reconstruction). A review of laryngeal reinnervation techniques, results in animal models, and the results achieved in patients are given. The clinical implications of reinnervation in unilateral as opposed to bilateral vocal fold paralysis are considered. For unilateral vocal fold paralysis and nonselective reinnervation, good voice results can be achieved. It has the advantage that no foreign materials need to be implanted and may also be used in a growing larynx in the case of children or adolescents. For bilateral vocal fold paralysis, good functional results, recovery of airway as well as voice, can be achieved with selective (or function-based) reinnervation.

Laryngeal Synkinesis: A Viable Condition for Laryngeal Pacing.

Laryngeal synkinesis as a form of defective healing is the rule rather than the exception in persistent vocal fold paralysis. It typically occurs 4-6 months after the onset of the recurrent laryngeal nerve paralysis. The incidence is up to 85%. Not all laryngeal muscles need to be equally affected. Reliable evidence can only be provided by a laryngeal electromyography. Physiological co-activation of the laryngeal muscles during antagonistic maneuvers must be considered. Although synkinesis undeniably worsens the prognosis for a motion recovery, it protects the muscle fibers from degeneration. A differentiation is required between favorable synkinesis (type I according to Crumley), which does not always require further therapy in the case of unilateral paralysis, and unfavorable forms of synkinesis (type II-IV) according to Crumley, which are associated with a functionally relevant malposition of the vocal fold(s) or with vocal fold jerks. Particularly when bilateral vocal fold motion does not return, type I synkinesis can be a good prerequisite for new dynamic therapy approaches, such as laryngeal pacing. The rarely occurring type II-IV synkinesis should, whenever possible, be transformed into a more favorable type I synkinesis by selective or non-selective reinnervation at an early stage of the disease. The latter applies to expected muscle atrophy with insufficient regrowth of nerve fibers.

Olfactory Ecto-Mesenchymal Stem Cells in Laryngeal Nerve Regeneration in Rats

Selective intralaryngeal reinnervation has been shown to be effective in experimental models. This consists of independently reinnerving the adductor and abductor of laryngeal muscles of the larynx, in order to prevent any misalignment of the axonal regrowth, improve the functional recovery and tend toward reduction of synkinesis. The surgical technique remains complex. Current research focuses on simplifying and improving this technique. Olfactory ectomesenchymal stem cells (OEMSC) represent an interesting candidate for cell therapy and could be obtained from olfactory mucosa. Recent reports suggest a neuroregenerative potential in various animal models of central and peripheral nervous systems injuries. The aim of this study was dual: to develop a simple surgical model of selective reinnervation applicable in humans and to evaluate the relevance of OEMSC-based cell therapy for improving axonal guidance. Eight Fisher syngeneic rats were used to carry out the OEMSCs culture. Thirty-four Fisher syngeneic rats were operated on, divided into three groups depending on the transplanting. For all the rats, we have performed a side to end anastomosis of the vagal nerve with the inferior laryngeal nerve by interposition of a nerve graft from the left femoral nerve. Then, the first group didn't have any injection, the second group has an injection of thrombin and the third group has an injection of one million EOMSCs. Three months after surgery, laryngeal muscle activity was evaluated by videolaryngoscopy and electromyography recordings. In order to illustrate the quality of axonal regrowth, a fluorescent tracer was injected into the right posterior crico-arytenoid muscle (PCA) to reveal the cellular bodies of the motoneurons responsible for reinnervation of the PCA in the central nervous system. In our study, no improvement was found during the videolaryngological functional evaluation or with regard to the electrical activity of the PCA muscle. The cells colabelled in retrograde tracing were numerous in all groups, reflecting abnormal axonal regeneration. The interposition of a nerve graft, as side to end anastomosis between the vagus nerve and the inferior laryngeal nerve, filled with OEMSCs, does not provide better reinnervation of a hemilarynx.

REINNERVATION AS A METHOD OF TREATMENT OF ONE-SIDED ABDUCTION LARYNX PARALYSIS IN OPERATIONS ON THYROID GLAND

Introduction. The use of selective larynx reinnervation creates the prerequisites for the resumption of synchronous mobility of the vocal folds and is used to correct breathing problems in the case of bilateral laryngeal paralysis, but it can be used to correct unilateral abduction paralysis during an operation on the thyroid gland. Objective: To assess the possibility of performing selective larynxreinnervation during abduction unilateral paralysis in thyroid surgery. Materials and methods: All patients underwent examination of the larynx (fibrolaryngoscopy with data archiving) before and after operation, as well as 4, 6,12,18 months after operation, voice spectral analysis, voice quality assessment (VHI-30), EAT-10 survey (determining the degree of dysphagia). Results. Selective reinnervation was carried out in 2 groups of patients with non-peel-shaped branching of RLN. Group 1 (1 patient) with pre-existing postoperative unilateral laryngeal abduction paralysis, severe dysphonic and moderate aspiration disorders, delayed selective larynx reinnervation was performed (autoplasty of the RLN adduction branch using n. transversus colli fragment). Group 2 (1 patient) performed primary selective larynx reinnervation in connection with resection of the adduction branch of the RLN (tumor invasion into it). An anastomosis of the end-to-end RLN branch of the RLN was performed with three epiperineural sutures. In a patient of group 1, a change in the tone and tension of the free edge of the «paralyzed» vocal fold was recorded 15 months after reinnervation, and the first signs of coordinated movement — after 18 months — fully recovered in almost 2 years. In a patient of group 2, the restoration of the tone of the «paralyzed» vocal fold and the restoration of its mobility were recorded 4 months after larynx reinnervation. In both patients, there was a recovery of the main indicators of the spectral analysis of the voice to normal values, as well as a decrease in the indices (points) of dysphagia on the EAT-10 scale and the index of voice disorders on the VHI-30 scale to normal. Conclusions: Selective larynx reinnervation is applicable not only to eliminate respiratory failure with bilateral laryngeal paralysis, but also to restore voice function, to eliminate the symptoms of aspiration in unilateral laryngeal paralysis. Taking into account the statistical unreliability of the groups of this research and the complexity of this methodology in practical application, it requires further study and a multidisciplinary approach.

Selective reinnervation for correction of unilateral paralysis of larynx in thyroidal surgery

Objective. To estimate the possibility of performance of selective reinnervation of larynx in its abductionaal unilateral paralysis in thyroidal surgery.&#x0D; Маterials and methods. There were analyzed the results of selective laryngeal reinnervation in 2 patients, suffering thyroidal cancer. Visual inspection of the larynx was conducted (fibrolaryngoscopy with archiving of the data) in preoperative and postoperative periods, аs well as in 2, 4, 6, 12, 18 and 24 mo postoperatively, spectral vocal analysis, estimation of vocal quality in accordance to the VHI-30 sсale reporting, using questionnaires ЕАТ-10 for determination of the dysphagia degree.&#x0D; Results. Selective reinnervation was performed in 2 patients with extralaryngeal branching of nervus recurrence: in one - the postponed selective reinnervation of larynx (аutoplasty of the adduction branch of nervus recurrence) for correction of its postoperative abductional paralysis, and in the second - primary selective laryngeal reinnervation (аnastomosis of the adductional branch of nervus recurrence in the “end-to-end” style). In the first patient the tone and stretching of the paralyzed vocal cord free edge was registered in 15 mo after reinnervation, the coordinated move signs - in 2 yrs. In a second patient the restoration of tone and mobility of a vocal cord was registered in 4 mo after reinnervation. In both patients the main indices of the voice spectral analysis and of the self-estimation in accordance to the VHI-30 and ЕАТ-10 scales were restored up to normal values.&#x0D; Conclusion. Selective reinnervation of larynx may be applied not for correction of respiratory disorders due to its bilateral paralysis only, but for restoration of a vocal function and elimination of aspiration symptoms in a case of unilateral paralysis of larynx as well.