Best Practices in Facial Nerve Monitoring

An analysis of health-related quality of life in children and adolescents after parotidectomy based on patient-reported outcomes

PURPOSE

To assess health-related quality of life (HRQoL) and its influencing factors in these pediatric patients undergoing parotidectomy.

METHODS

This was a cross-sectional study that included 37 children and adolescents (≤ 19 years) with parotid gland tumors who were treated in Sichuan Cancer Hospital between January 2006 and November 2021. HRQoL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30). The Wilcoxon rank sum test was used to analyze the factors influencing patients' HRQoL.

RESULTS

37 children and adolescents were included in the study, including 22 cases of benign tumors and 15 cases of malignant tumors. All patients underwent surgery, and some patients with malignant tumors received radiotherapy or chemotherapy. Malignancy, permanent facial palsy, and Frey syndrome were associated with worse HRQoL in children and adolescents with parotid gland tumors. Radiotherapy and no cervical lymph node dissection were associated with worse HRQoL in pediatric patients with malignancy. The surgical approach of parotid is not a factor influencing HRQoL.

CONCLUSION

Factors associated with HRQoL in children and adolescents with parotid gland tumors include pathological types, permanent facial palsy, and Frey syndrome. In addition, factors affecting patients with malignancy include lateral lymph node dissection and radiotherapy.

A novel method of neurophysiological brainstem mapping in neurosurgery

BACKGROUND

Brainstem mapping with electrical stimulation allows functional identification of neural structures during resection of deep lesions. Single pulses or train of pulses are delivered to map cranial nerves and corticospinal tracts, respectively.

NEW METHOD

We introduce a hybrid stimulation technique for mapping the brainstem. The stimulus consists of an electrical single pulse followed by a short train of 3-5 pulses at 500 Hz, at an interval of 60-75 ms. The responses to this stimulation pattern are recorded from appropriate cranial and limb muscles.

RESULTS

Both the single pulse and the short train elicit electromyographic responses when motor fibers or motor nuclei of the cranial nerves are stimulated. Responses to the train but not to the preceding single pulse indicate activation of the descending motor tracts, in the mesencephalon and the pons. Conversely, in the medulla, limb responses to stimulation of the corticospinal tracts are elicited by a single pulse. Identification of the extra and intra-axial courses of the trigeminal motor and sensory fibers is possible by recording responses from the masseter and the tongue muscles.

COMPARISON WITH EXISTING METHOD(S)

To date, either a pulse or a train is delivered during brainstem mapping, switching from one to the other modality according to the expected target structure. This procedure can be time-consuming and may even lead to false negative responses to the stimulation, eventually leading to inaccurate neurosurgical procedures.

CONCLUSIONS

The novel hybrid pulse-train technique enhances the advantage of brainstem mapping procedure, minimizing pitfalls and improving patient safety.

Visualization of the Facial Nerve with Ultra-high-Frequency Ultrasound

Background

Profound variations in facial nerve branching, combined with the severe impact of facial palsy on the patient's quality of life, make surgery in this region challenging. Recent advancements in ultrasound (US) technology, including the improved visualization of small structures, have led to a sharp increase in its medical indications in various medical disciplines. We aimed to prove the feasibility of using ultra-high-frequency (UHF) US to visualize the facial nerve and to guide surgeons during surgery on and around the facial nerve.

Methods

A cadaveric study was performed on one hemi-face with a UHF US imaging system and state-of-the-art transducers. Firstly, a transcutaneous US was performed, and the facial nerve branches of interest (zygomatic, buccal, and marginal mandibular branches) were marked using US-guided color-injections of filler mixed with methylene blue. Skin and subcutaneous fat were then removed to simulate the intraoperative field. Secondly, an "intraoperative" US examination was performed, and the same branches were marked by US-guided color-injections of filler mixed with indocyanine green. Anterograde facial nerve dissection was performed, and the distance between the nerve branches and the injected filler was measured.

Results

All color-injections (mixed with both methylene blue and indocyanine green) were positioned right next to the nerve branches (<1 mm). The image quality of the US below the skin was observed to be far superior to that of the transcutaneous US.

Conclusion

UHF US can be used to visualize the facial nerve with high precision both transcutaneously and intraoperatively (after elevation of the skin flap).

Litigation in pediatric otorhinolaryngology: Lessons in improving patient care

OBJECTIVE(S)

Medico-legal claims involving children place a substantial financial burden on health services and have a profound emotional and psychological impact on clinicians. Our objective was to analyze both the common causes and cost of litigation in pediatric otorhinolaryngology.

METHODS

A retrospective review of all clinical negligence claims within pediatric otolaryngology (0-17 years inclusive) in NHS (National Health Service) England held by the clinical negligence service 'NHS Resolution between' 4/2013 and 4/2020.

RESULTS

There were 100 claims in pediatric otorhinolaryngology accounting for an estimated potential total cost of just under £49 million with an average of 14 claims per year. Over half (52%) of claims were related to an operation with cause codes "Operator Error/Intra-Op Problem", "Diathermy Injury" and "Failure to Warn - Consent" most cited. The most common operation cited in a claim was tonsillectomy with an average cost per claim of £47,084. There were 21 claims coded as either "failure to diagnose" or "failure to treat" in relation to cholesteatoma, with an average cost per claim of £61,086.

CONCLUSION

This is the largest study to date analyzing the reasons and potential cost of clinical negligence claims within pediatric otolaryngology. Many learning opportunities exist to reduce patient morbidity, mortality and improve the patient experience through litigation data analysis.

A Comprehensive Approach to Facial Reanimation: A Systematic Review

Purpose: To create a systematic overview of the available reconstructive techniques, facial nerve grading scales, physical evaluation, the reversibility of paralysis, non-reconstructive procedures and medical therapy, physical therapy, the psychological aspect of facial paralysis, and the prevention of facial nerve injury in order to elucidate the gaps in the knowledge and discuss potential research aims in this area. A further aim was to propose an algorithm simplifying the selection of reconstructive strategies, given the variety of available reconstructive methods and the abundance of factors influencing the selection. Methodological approach: A total of 2439 papers were retrieved from the Medline/Pubmed and Cochrane databases and Google Scholar. Additional research added 21 articles. The primary selection had no limitations regarding the publication date. We considered only papers written in English. Single-case reports were excluded. Screening for duplicates and their removal resulted in a total of 1980 articles. Subsequently, we excluded 778 articles due to the language and study design. The titles or abstracts of 1068 articles were screened, and 134 papers not meeting any exclusion criterion were obtained. After a full-text evaluation, we excluded 15 papers due to the lack of information on preoperative facial nerve function and the follow-up period. This led to the inclusion of 119 articles. Conclusions: A thorough clinical examination supported by advanced imaging modalities and electromyographic examination provides sufficient information to determine the cause of facial palsy. Considering the abundance of facial nerve grading scales, there is an evident need for clear guidelines regarding which scale is recommended, as well as when the postoperative evaluation should be carried out. Static procedures allow the restoral of facial symmetry at rest, whereas dynamic reanimation aims to restore facial movement. The modern approach to facial paralysis involves neurotization procedures (nerve transfers and cross-facial nerve grafts), muscle transpositions, and microsurgical free muscle transfers. Rehabilitation provides patients with the possibility of effectively controlling their symptoms and improving their facial function, even in cases of longstanding paresis. Considering the mental health problems and significant social impediments, more attention should be devoted to the role of psychological interventions. Given that each technique has its advantages and pitfalls, the selection of the treatment approach should be individualized in the case of each patient.

Monitoring cerebellopontine angle and skull base surgeries

Cerebellopontine angle (CPA) surgery represents a challenge for neurosurgeons due to the high risk of iatrogenic injury of vital neurological structures. Therefore, important efforts in improving the surgical techniques and intraoperative neurophysiology have been made in the last decades. We present a description and review of the available methodologies for intraoperative neuromonitoring and mapping during CPA surgeries. There are three main groups of techniques to assess the functional integrity of the nervous structures in danger during these surgical procedures: (1) Electrical identification or mapping of motor cranial nerves (CNs), which is essential in order to locate the nerve in their different parts during the tumor resection; (2) Monitoring, which provides real-time information about functional integrity of the nervous tissue; and (3) Brainstem reflexes including blink reflex, masseteric reflex, and laryngeal adductor reflex. All these methods facilitate the removal of lesions and contribute to notable improvement in functional outcome and permit on the investigation of their physiopathology in certain neurosurgically treated diseases. Such is the case of hemifacial spasm (HFS). We describe the methodology to evaluate the efficacy of microvascular decompression for HFS treatment at the end of this chapter.