Rethinking Oncologic Facial Nerve Reconstruction in the Acute Phase Through Classification of the Level of Injury.

Early facial nerve reconstruction should be offered in every patient with oncological resections of the facial nerve due to the debilitating functional and psychosocial consequences of facial nerve palsy. Oncologic pathology or oncologic resection accounts for the second most common cause of facial nerve palsy. In the case of these acute injuries, selecting an adequate method for reconstruction to optimize functional and psychosocial well-being is paramount. Authors advocate consideration of the level of injury as a framework for approaching the viable options of reconstruction systematically. Authors breakdown oncologic injuries to the facial nerve in three levels in relation to their nerve reconstruction methods and strategies: Level I (intracranial to intratemporal), Level II (intratemporal to extratemporal and intraparotid), and Level III (extratemporal and extraparotid). Clinical features, common clinical scenarios, donor nerves available, recipient nerve, and reconstruction priorities will be present at each level. Additionally, examples of clinical cases will be shared to illustrate the utility of framing acute facial nerve injuries within injury levels. Selecting donor nerves is critical in successful facial nerve reconstruction in oncological patients. Usually, a combination of facial and nonfacial donor nerves (hybrid) is necessary to achieve maximal reinnervation of the mimetic muscles. Our proposed classification of three levels of facial nerve injuries provides a selection guide, which prioritizes methods for function nerve reconstruction in relation of the injury level in oncologic patients while prioritizing functional outcomes.

Malignant Peripheral Nerve Sheath Tumors of the Brachial Plexus: A Single-Center Experience on Diagnosis, Management, and Outcomes.

INTRODUCTION: The incidence of malignant peripheral nerve sheath tumors (MPNSTs) is 0.001%. Commonly, MPNST arise in neurofibromatosis; however, they can occur sporadically, de novo or from a preexisting neurofibroma. Malignant peripheral nerve sheath tumors are aggressive tumors with high rates of local recurrence and metastasis. The prognosis is poor with 5-year survival rates of 15% to 50%. Unfortunately, given the rarity of these tumors, it is not clear how to best manage these patients. The purposes of this study were (1) to discuss our experience with MPNST and particularly our difficulties with diagnosis and management, and (2) to review the literature. MATERIALS AND METHODS: We report on all tumors of the brachial plexus excised between 2013 and 2019. We report 3 cases of MPNST, their treatment, and their outcomes. RESULTS: Thirteen patients underwent surgical excision of an intrinsic brachial plexus mass. Three of these patients (2 male, 1 female; average age, 36 years) were diagnosed with an MPNST. Two patients with an MPNST had neurofibromatosis type 1. All patients with an MPNST had a tumor >8 cm, motor and sensory deficits, and pain. All 3 patients with MPNST underwent a magnetic resonance imaging (MRI) before diagnosis. The average time from initial symptom onset to MRI was 12.3 months. Only 1 of the MRIs suggested a malignant tumor, with no MRI identifying an MPNST. One patient underwent an excisional biopsy, and 2 had incisional biopsies. Because of the lack of diagnosis preoperatively, all patients had positive margins given the limited extent of surgery. Returning for excision in an attempt to achieve negative margins in a large oncologically contaminated field was not possible because defining the boundaries of the initial surgical field was unachievable; therefore, the initial surgery was their definitive surgical management. All patients were referred to oncology and received radiation therapy. CONCLUSIONS: Malignant peripheral nerve sheath tumors must be suspected in enlarging masses (>5 cm) with the constellation of pain, motor, and sensory deficits. Computed tomography- or ultrasound-guided core needle biopsy under brachial plexus block or sedation is required for definitive diagnosis to allow for a comprehensive approach to the patient's tumor with a higher likelihood of disease-free survival.

Robot-Assisted Microsurgery-what does the learning curve look like?

Background: The introduction of robotic assistance in surgical practice has led to advancements such as the MUSA-2 robotic system that was designed for microsurgical procedures. Advantages of this system include tremor filtration and motion scaling. Initial studies showed promising results in skill acquisition for robot-assisted microsurgery. This study evaluated the learning curve for microsurgical anastomosis with and without robotic assistance among surgeons of varying experience levels. Methods: Fifteen surgeons were divided into 3 groups (novice, intermediate, and expert) based on their microsurgical experience. They performed 10 anastomoses by hand and 10 with robotic assistance on synthetic polyvinyl alcohol vessels (diameter of 2 mm) in a laboratory setting. Participants were timed and mistakes such as backwall and leakage were assessed and recorded. Demographic information was collected. Results: Statistical differences were found in manual anastomosis times between the intermediate and novice groups compared to the experts (p < 0.01). However, no statistical difference was found in the mean time between groups for the robot-assisted anastomoses. Novice doctors had the steepest learning curve for hand-sewn anastomosis. Experts had the fastest completion time at the end of the 10th robotic session, finishing at 14 min, compared to 33 min at the 2nd session. All groups reduced their mean time in half through their 10 robotic sessions. Conclusion: This study indicated similarities in the learning curves for robot-assisted anastomosis among surgeons with varied experience levels. Experts excelled technically in manual anastomoses, but robot-assistance enabled novice and intermediate surgeons to perform comparably to the experts. Robotic assistance may aid more novice learners in performing microsurgical anastomosis safely at earlier points in their education.

A Novel Silicone Simulation Model for Microvascular Anastomosis.

Purpose: Surgical simulation of microvascular anastomosis has become increasingly popular. There are several living and silicone models available. Current silicone models fail to accurately reproduce a vessel's loose adventitial layer, which may lead to the development of improper microsurgical technique. Our purpose is to create a realistic 3-dimensional microsurgical simulator that incorporates an adventitial vessel layer for higher fidelity manipulation of vessels. Methods: A microvascular anastomosis simulator was manufactured using metal moulds and inorganic materials. Synthetic tubing was created with a metal cylinder, 1.65 mm in diameter, painted with 2 sequential layers of silicon with a shore hardness of 2A. Silicone was allowed to fully cure in-between layers. Vessel adventitia was created with a 100-micron polyester mesh adhered to the silicone vessel exterior. Once dry, the synthetic tube is removed from the metal cylinder is then clipped to reveal the inner lumen. Both Resident and attending physicians evaluated the model with and without the adventitial layer and completed a questionnaire. Results: Grasping and manipulation of the vessel were scored on Average score 4.5 and 3 out of 5, with adventitia and without, respectively (P = .00906). Usefulness as a teaching tool was scored on average 4.9 and 4.2, with adventitia and without, respectively (P = .0232). The analysis included: simulation realism, educational utility, and overall satisfaction. Responses in all domains were favourable, suggesting the utility of this model. Conclusion: We created a realistic, high fidelity microvascular anastomosis simulator that is low cost and easily reproducible. Initial feedback is encouraging regarding realism, educational utility, and overall usefulness. Further validation is required to assess its effectiveness in resident education and skill transfer to the operating room.

Objectif: La simulation chirurgicale de l'anastomose microvasculaire gagne en popularité. Il existe plusieurs modèles de simulation vivants ou en silicone. Les modèles actuels en silicone ne réussissent pas à reproduire la couche adventitielle lâche, ce qui peut entraîner une technique microchirurgicale inappropriée. Les chercheurs voulaient créer un simulateur microchirurgical tridimensionnel réaliste doté d'une couche adventitielle pour manipuler les vaisseaux avec plus de fiabilité. Méthodologie: Les chercheurs ont fabriqué un simulateur d'anastomose microvasculaire au moyen de moules métalliques et de matières inorganiques. Ils ont créé des tubulures synthétiques à l'aide d'un cylindre métallique d'un diamètre de 1,65 mm, qu'ils ont peint de deux couches séquentielles de silicone d'une dureté Shore A de 2. Ils ont laissé le silicone durcir complètement entre les couches et ont créé la couche adventitielle à l'aide d'une maille de polyester de 100 microns fixée à l'extérieur du vaisseau de silicone. Une fois sèche, la tubulure synthétique est retirée du cylindre métallique, puis coupée pour révéler la lumière interne. Des résidents et des médecins traitants ont évalué le modèle avec et sans la couche adventitielle et rempli un questionnaire. Résultats: La saisie et la manipulation du vaisseau ont obtenu un score moyen de 4,5 et de 3 sur 5, avec et sans la couche adventitielle, respectivement (p = 0,00906). L'utilité de ce vaisseau comme outil d'enseignement a obtenu un score moyen de 4,9 et de 4,2, avec et sans la couche adventitielle, respectivement (p = 0,0232). L'analyse incluait le réalisme de la simulation, l'utilité pour l'enseignement et la satisfaction globale. Les réponses étaient favorables dans tous les domaines, ce qui laisse croire à l'utilité du modèle. Conclusion: Les chercheurs ont créé un simulateur d'anastomose microvasculaire haute-fidélité réaliste, à la fois peu coûteux et facile à reproduire. Les premiers commentaires sont encourageants pour ce qui est du réalisme, de l'utilité pour l'enseignement et de l'utilité globale. Son efficacité lors de l'enseignement aux résidents et du transfert du savoir en salle d'opération devra être validée davantage.