UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.
UNASSIGNED: Single-stage facial reanimation effectively restores facial function in patients undergoing radical parotidectomy. This approach offers significant benefits in early facial function recovery.

A regenerative peripheral nerve interface (RPNI) offers a therapeutic solution for nerve injury through reconstruction of the target muscle. However, implanting a transected peripheral nerve into an autologous skeletal muscle graft in RPNI causes donor-site morbidity, highlighting the need for tissue-engineered skeletal muscle constructs. Here, an engineered regenerative isolated peripheral nerve interface (eRIPEN) is developed using 3D skeletal cell printing combined with direct electrospinning to create a nanofiber membrane envelop for host nerve implantation. In this in vivo study, after over 8 months of RPNI surgery, the eRIPEN exhibits a minimum Feret diameter of 15-20 µm with a cross-sectional area of 100-500 µm2, representing the largest distribution of myofibers. Furthermore, neuromuscular junction formation and muscle contraction with a force of ≈28 N are observed. Notably, the decreased hypersensitivity to mechanical/thermal stimuli and an improved tibial functional index from -77 to -56 are found in the eRIPEN group. The present novel concept of eRIPEN paves the way for the utilization and application of tissue-engineered constructs in RPNI, ultimately realizing neuroprosthesis control through synaptic connections.

Breast sensation plays a significant role in the safety and quality of life of women who undergo mastectomy and reconstruction. In 1992, Slezak et al. introduced the concept of abdominal flap neurotization to improve sensation of the reconstructed breast. Over the next 30 years, numerous studies iterated on Slezak\'s technique, suggesting technical modifications and new methodologies for assessing sensory recovery. Despite evidence that reinnervation increases patient satisfaction following autologous breast reconstruction, abdominal flap neurotization remains a rarely performed procedure. In this article, we review the evolution of flap neurotization in breast reconstruction and describe our approach to facilitating sensory recovery of the breast while limiting donor site morbidity.

OBJECTIVE: Laryngeal cancer resections often require excision of portions of the larynx along with sacrifice of the ipsilateral recurrent laryngeal nerve (RLN). In such cases, there are no reconstructive options that reliably restore laryngeal function, rendering patients with severe functional impairment. To address this unmet clinical need, we extend our evaluation of a 3-implant mucosal, muscle, cartilage reconstruction approach aimed at promoting functional laryngeal restoration in a porcine hemilaryngectomy model with ipsilateral RLN transection.
METHODS: Six Yucatan mini-pigs underwent full-thickness hemilaryngectomies with RLN transection followed by transmural reconstruction using fabricated collagen polymeric mucosal, muscle, and cartilage replacements. To determine the effect of adding therapeutic cell populations, subsets of animals received collagen muscle implants containing motor-endplate-expressing muscle progenitor cells (MEEs) and/or collagen cartilage implants containing adipose stem cell (ASC)-derived chondrocyte-like cells. Acoustic vocalization and laryngeal electromyography (L-EMG) provided functional assessments and histopathological analysis with immunostaining was used to characterize the tissue response.
RESULTS: Five of six animals survived the 4-week postoperative period with weight gain, airway maintenance, and audible phonation. No tracheostomy or feeding tube was required. Gross and histological assessments of all animals revealed implant integration and regenerative remodeling of airway mucosa epithelium, muscle, and cartilage in the absence of a material-mediated foreign body reaction or biodegradation. Early voice and L-EMG data were suggestive of positive functional outcomes.
CONCLUSIONS: Laryngeal reconstruction with collagen polymeric mucosa, muscle, and cartilage replacements may provide effective restoration of function after hemilaryngectomy with RLN transection. Future preclinical studies should focus on long-term functional outcomes.
METHODS: NA Laryngoscope, 2024.

A common sequela of peripheral nerve injury is aberrant regeneration and recovery. Aberrant regeneration of injured motor nerves can affect all aspects of the nerve circuit from the motor cortex to the target muscle. A more comprehensive term for the symptoms that develop after aberrant motor neuromuscular reinnervation is aberrant reinnervation syndrome (ARS). Injury to the facial nerve followed by aberrant reinnervation results in a spectrum of symptoms that has been called many things in the literature. The authors support that this commonly encountered sequela of facial nerve injury be called facial aberrant reinnervation syndrome (FARS), a term that is more descriptive of the underlying pathophysiology and more inclusive of the clinical symptoms: facial synkinesis, facial muscle hypertonicity, and facial muscle spasm/twitching, which occur following facial nerve injury and recovery. In the following article, we present the clinical manifestations and sequelae of facial nerve injury and recovery and briefly discuss our evolving understanding of the pathophysiology and treatment of FARS.

Across vertebrate species, the olfactory epithelium (OE) exhibits the uncommon feature of lifelong neuronal turnover. Epithelial stem cells give rise to new neurons that can adequately replace dying olfactory receptor neurons (ORNs) during developmental and adult phases and after lesions. To relay olfactory information from the environment to the brain, the axons of the renewed ORNs must reconnect with the olfactory bulb (OB). In Xenopus laevis larvae, we have previously shown that this process occurs between 3 and 7 weeks after olfactory nerve (ON) transection. In the present study, we show that after 7 weeks of recovery from ON transection, two functionally and spatially distinct glomerular clusters are reformed in the OB, akin to those found in non-transected larvae. We also show that the same odourant response tuning profiles observed in the OB of non-transected larvae are again present after 7 weeks of recovery. Next, we show that characteristic odour-guided behaviour disappears after ON transection but recovers after 7-9 weeks of recovery. Together, our findings demonstrate that the olfactory system of larval X. laevis regenerates with high accuracy after ON transection, leading to the recovery of odour-guided behaviour.

Advancement in microsurgical techniques and innovative approaches including greater use of nerve and tendon transfers have resulted in better peripheral nerve injury (PNI) surgical outcomes. Clinical evaluation of the patient and their injury factors along with a shift toward earlier time frame for intervention remain key. A better understanding of the pathophysiology and biology involved in PNI and specifically mononeuropathies along with advances in ultrasound and magnetic resonance imaging allow us, nowadays, to provide our patients with a logical and sophisticated approach. While functional outcomes are constantly being refined through different surgical techniques, basic scientific concepts are being advanced and translated to clinical practice on a continuous basis. Finally, a combination of nerve transfers and technological advances in nerve/brain and machine interfaces are expanding the scope of nerve surgery to help patients with amputations, spinal cord, and brain lesions.

OBJECTIVE: This paper reviews the current literature about epidemiology, etiologies, diagnosis, and management of pediatric bilateral vocal fold paralysis (PBVFP).
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.

BACKGROUND: Skin-grafted free gracilis muscle flaps are commonly used for lower extremity reconstruction. However, the loss of sensory function may lead to increased patient morbidity. This study prospectively analyzed the sensory and neuropathic pain outcomes of neurotized skin-grafted free gracilis muscle flaps used for the reconstruction of lower extremity defects.
METHODS: Patients undergoing lower extremity reconstructions between 2020 and 2022 with neurotized skin-grafted free gracilis muscle flaps were prospectively enrolled. Sensation was assessed at 3, 6 and 12 months postoperatively using monofilaments, two-point discrimination, a vibration device, and cold and warm metal rods. Sensations were tested in the center and periphery of the flaps, as well as in the surrounding skin. The contralateral side served as the control. Patients completed the McGill pain questionnaire to evaluate patient-reported neuropathic pain.
RESULTS: Ten patients were included. At 12 months postoperatively, monofilament values improved by 44.5% compared to that of the control site, two-point discrimination, cold detection, warmth detection, and vibration detection improved by 36.2%, 48%, 50%, and 88.2%, respectively, at the reconstructed site compared to those at the control site. All sensory tests were significantly better than 3 and 6 months values (p < 0.05), but remained significantly poorer than the control site (p < 0.05). Sensation in the central flap areas were similar to peripheral flap areas throughout the follow-up period (p > 0.05). The surrounding skin reached values similar to the control site at 12 months (p > 0.05). Moreover, 50% of patients reported neuropathic pain at 3 months postoperatively, 40% at 6 months, and 0% at 12 months (p < 0.05).
CONCLUSIONS: Mechanical detection, vibration detection, temperature detection, and two-point discrimination significantly improved over time but without reaching normal sensory function at 12 months postoperatively. Neuropathic pain resolved at 12 months.

OBJECTIVE: This study evaluated the long-term outcomes of intraoperative recurrent laryngeal nerve (RLN) reinnervation for managing thyroidectomy-related unilateral vocal fold paralysis (UVFP) over a period of 10 years and assessed the long-term efficacy of this technique.
METHODS: This study was conducted between March 2006 and July 2022 at Soonchunhyang University Bucheon Hospital. We enrolled 25 patients who underwent RLN reinnervation via direct neurorrhaphy or ansa cervicalis-to-RLN anastomosis and completed subjective and objective voice measurements over 5 years period. Among these, 10 patients completed voice measurements over 10 years period.
RESULTS: Six months post-RLN reinnervation, most subjective voice parameters and some of objective voice parameters showed significant improvement (p < 0.05). Twelve months after the procedure, most parameters demonstrated significant voice improvements. These improvements remained stable in follow-up examinations 10 years post-RLN reinnervation (p < 0.05).
CONCLUSIONS: With stable voice outcomes over a decade, primary intraoperative RLN reinnervation provides satisfactory voice outcomes for 10 years postoperatively. Concerning the long-term survival of thyroid cancer patients, primary intraoperative RLN reinnervation is the first recommended voice rehabilitation technique for thyroidectomy related permanent UVFP.