Modern concepts in facial nerve reconstruction

<p>Abstract</p> <p>Background</p> <p>Reconstructive surgery of the facial nerve is not daily routine for most head and neck surgeons. The published experience on strategies to ensure optimal functional results for the patients are based on small case series with a large variety of surgical techniques. On this background it is worthwhile to develop a standardized approach for diagnosis and treatment of patients asking for facial rehabilitation.</p> <p>Conclusion</p> <p>A standardized approach is feasible: Patients with chronic facial palsy first need an exact classification of the palsy's aetiology. A step-by-step clinical examination, if necessary MRI imaging and electromyographic examination allow a classification of the palsy's aetiology as well as the determination of the severity of the palsy and the functional deficits. Considering the patient's desire, age and life expectancy, an individual surgical concept is applicable using three main approaches: a) early extratemporal reconstruction, b) early reconstruction of proximal lesions if extratemporal reconstruction is not possible, c) late reconstruction or in cases of congenital palsy. Twelve to 24 months after the last step of surgical reconstruction a standardized evaluation of the therapeutic results is recommended to evaluate the necessity for adjuvant surgical procedures or other adjuvant procedures, e.g. botulinum toxin application. Up to now controlled trials on the value of physiotherapy and other adjuvant measures are missing to give recommendation for optimal application of adjuvant therapies.</p

Trends in treatment of head and neck cancer in germany: A diagnosis-related-groups-based nationwide analysis, 2005–2018

Simple Summary Surgery, radiotherapy, and chemotherapy/immunotherapy as monotherapy or in combination are the pillars of the treatment of head and neck cancer (HNC). Nation-wide population-based data on treatment rates per population and year for HNC are sparse. The data of virtually all HNC cases (apart from thyroid cancer) treated as inpatients in Germany between 2005 and 2018 were analyzed. Treatment rates for nearly all treatment types increased for cancer of the oral cavity, oropharynx, and salivary glands. Treatment rates for nasopharyngeal cancer in both sexes and hypopharyngeal cancer in men mainly decreased. In women, surgery for hypopharyngeal cancer decreased, but radiotherapy, chemotherapy, or in combination, increased. Laryngeal cancer showed a mixed picture: Surgery and neck dissection decreased in men and remained unchanged in women, whereas radiotherapy, chemotherapy, or in combination, remained unchanged in men, but increased in women. Changes in treatment are dependent on the subsites and are different for men and women for several subsites. Abstract Advances in head and neck cancer (HNC) treatment might have changed treatment strategies. This study determined, with focus on gender disparity, whether treatment rates have changed for inpatients in Germany between 2005 and 2018. Nation-wide population-based diagnosis-related groups (DRG) data of virtually all HNC cases (1,226,856 procedures; 78% men) were evaluated. Poisson regression analyses were used to study changes of annual treatment rates per German population. For surgery, the highest increase was seen for women with cancer of the oral cavity (relative risk (RR) 1.14, 95% confidence interval (CI) 1.11–1.18, p < 0.0001) and the highest decrease for men with laryngeal cancer (RR 0.90, CI 0.87–0.93). In women with oropharyngeal cancer, the highest increase of radiotherapy rates was seen (RR 1.18, CI 1.10–1.27, p < 0.0001). A decrease was seen in men for hypopharyngeal cancer (RR 0.93, CI 0.87–0.98, p = 0.0093). The highest increase for chemotherapy/immunotherapy was seen for women with oropharyngeal cancer (RR 1.16, CI 1.08–1.24, p < 0.0001), and a decrease in men with hypopharyngeal cancer (RR 0.93, CI 0.88–0.97, p = 0.0014). Treatment patterns had changed for nearly all subsites and therapy types. There were relevant gender disparities, which cannot be explained by the DRG data

Surgery for bilateral vocal fold paralysis: Systematic review and meta-analysis

ObjectivesTo determine the decannulation rate (DR) and revision surgery rate after surgery for bilateral vocal fold paralysis (BVFP).Data SourcesFive databases (MEDLINE, PubMed, Embase, Web of Science, Scopus) were searched for the period 1908–2020.MethodsThe systematic literature review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were pooled using a random-mixed-effects model. Randomized controlled trials and non-randomized studies (case-control, cohort, and case series) were included to assess DR and revision surgery rate after different surgical techniques for treatment of BVFP.ResultsThe search yielded 857 publications, of which 102 with 2802 patients were included. DR after different types of surgery was: arytenoid abduction (DR 0.93, 95%-confidence interval [CI], 0.86–0.97), endolaryngeal arytenoidectomy (DR 0.92, 95%-CI, 0.86–0.96), external arytenoidectomy (DR 0.94; 95%-CI, 0.71–0.99), external arytenoidectomy and lateralisation (DR 0.87; 95%-CI, 0.73–0.94), laterofixation (DR 0.95; 95%-CI, 0.91–0.97), posterior cordectomy (DR 0.97, 95%-CI, 0.94–0.99), posterior cordectomy and arytenoidectomy (DR 0.98, 95%-CI, 0.93–0.99), posterior cordectomy and subtotal arytenoidectomy (DR 0.98, 95%-CI, 0.88–1.00), posterior cordotomy (DR 0.96, 95%-CI, 0.84–0.99), reinnervation (0.69, 95%-CI, 0.12–0.97), subtotal arytenoidectomy (DR 1.00, 95%-CI, 0.00–1.00) and transverse cordotomy (DR 1.0, 95%-CI, 0.00–1.00). No significant difference between subgroups for DR could be found (Q = 15.67, df = 11, p = 0.1540). The between-study heterogeneity was low (τ2 = 2.2627; τ = 1.5042; I2 = 0.0%). Studies were at high risk of bias.ConclusionBLVP is a rare disease and the study quality is insufficient. The existing studies suggest a publication bias and the literature review revealed that there is a lack of prospective controlled studies. There is a lack of standardized measures that takes into account both speech quality and respiratory function and allows adequate comparison of surgical methods

Parameters of Stromal Activation and Epithelial to Mesenchymal Transition as Predictive Biomarkers for Induction Chemotherapy in Patients With Locally Advanced Oral Cavity and Oropharyngeal Squamous Cell Cancer

Objectives Induction chemotherapy (IC) is likely to be effective for biologically distinct subgroups of oral cancer and biomarker development may lead to identification of those patients. Methods We evaluated immune cell infiltration, stroma formation and structure of the invasive front as well as the immunohistochemical expression of alpha smooth muscle actin (ASMA), CD163, E-cadherin, N-cadherin, and the laminin gamma 2 chain in pretreatment biopsy specimens and surgical resections after IC in 20 patients with locally advanced oral cancer who were treated in a prospective, ongoing, phase II trial on IC using docetaxel, cisplatin, and 5-fluorouracil (TPF). Results Significant negative prognostic factors for incomplete pathological tumor response to IC were alcohol abuse (P=0.032), cN+ (P=0.042), and <30% tumor reduction after first cycle of IC (P=0.034). Of the investigated histological parameters and biomarkers only a low membrane-bound expression of E-cadherin showed a trend to be associated with incomplete response to IC (P=0.061). Low expression of ASMA in stromal vessels and a strong tumor invasion front were significantly associated to tumor recurrence (P=0.024 and P=0.004, respectively). The median follow-up of all patients was 35 months. Alcohol abuse (P<0.001), <30% tumor reduction after first cycle of IC (P=0.005), and a strong tumor invasion front (P=0.019) were negative prognostic factors for overall survival. Conclusion A strong predictive biomarker among the investigated parameters for benefitting from TPF IC could not be found. The extent of the tumor invasion front was a negative prognostic marker for recurrence and survival in oral cancer treated by TPF IC followed by surgery and postoperative radiochemotherapy

Surface electrical stimulation for facial paralysis is not harmful

Introduction: Does electrical stimulation (ES) of denervated muscles delay or prevent reinnervation, or increase synkinesis? This retrospective study evaluated the outcome with and without ES of patients with acutely denervated facial muscles. Methods: The effect of ES was analyzed in two experiments: In 39 patients (6 with home-based ES, median 17.5 months) undergoing facial nerve reconstruction surgery (FNRS). Time to recovery of volitional movements was analyzed. The second experiment involved 13 patients (7 with ES, median 19 months) during spontaneous reinnervation. Sunnybrook and eFACE scoring provided functional outcome measures. Results: No difference in time of reinnervation after FNRS was found between the patients with and without ES (median (IQR) 4.5(3.0, 5.25) vs. 5.7(3.5, 9.5) months; p=0.2). After spontaneous reinnervation less synkinesis was noted (Sunnybrook synkinesis: 3.0(2.0, 3.0) vs. 5.5(4.75, 7.0); p=0.02) with ES. Discussion: We find no evidence that ES prevents or delays reinnervation or increases synkinesis in facial paralysis

Let's Get the FACS Straight -- Reconstructing Obstructed Facial Features

The human face is one of the most crucial parts in interhuman communication. Even when parts of the face are hidden or obstructed the underlying facial movements can be understood. Machine learning approaches often fail in that regard due to the complexity of the facial structures. To alleviate this problem a common approach is to fine-tune a model for such a specific application. However, this is computational intensive and might have to be repeated for each desired analysis task. In this paper, we propose to reconstruct obstructed facial parts to avoid the task of repeated fine-tuning. As a result, existing facial analysis methods can be used without further changes with respect to the data. In our approach, the restoration of facial features is interpreted as a style transfer task between different recording setups. By using the CycleGAN architecture the requirement of matched pairs, which is often hard to fullfill, can be eliminated. To proof the viability of our approach, we compare our reconstructions with real unobstructed recordings. We created a novel data set in which 36 test subjects were recorded both with and without 62 surface electromyography sensors attached to their faces. In our evaluation, we feature typical facial analysis tasks, like the computation of Facial Action Units and the detection of emotions. To further assess the quality of the restoration, we also compare perceptional distances. We can show, that scores similar to the videos without obstructing sensors can be achieved.Comment: VISAPP 2023 pape

Treatment With Nimodipine or FK506 After Facial Nerve Repair Neither Improves Accuracy of Reinnervation Nor Recovery of Mimetic Function in Rats

Purpose Nimodipine and FK506 (Tacrolimus) are drugs that have been reported to accelerate peripheral nerve regeneration. We therefore tested these substances aiming to improve the final functional outcome of motoric reinnervation after facial nerve injury. Methods In 18 female rats, the transected facial nerve was repaired by an artificial nerve conduit. The rats were then treated with either placebo, nimodipine, or FK506, for 56 days. Facial motoneurons were pre-operatively double-labeled by Fluoro-Gold and again 56 days post-operation by Fast-Blue to measure the cytological accuracy of reinnervation. The whisking motion of the vibrissae was analyzed to assess the quality of functional recovery. Results On the non-operated side, 93–97% of those facial nerve motoneurons innervating the vibrissae were double-labeled. On the operated side, double-labeling only amounted to 38% (placebo), 40% (nimodipine), and 39% (FK506), indicating severe misdirection of reinnervation. Regardless of post-operative drug or placebo therapy, the whisking frequency reached 83–100% of the normal value (6.0 Hz), but whisking amplitude was reduced to 33–48% while whisking velocity reached 39–66% of the normal values. Compared to placebo, statistically neither nimodipine nor FK506 improved accuracy of reinnervation and function recovery. Conclusion Despite previous, positive data on the speed and quantity of axonal regeneration, nimodipine and FK506 do not improve the final functional outcome of motoric reinnervation in rats

A Proposal to Perform High Contrast Imaging of Human Palatine Tonsil with Cross Polarized Optical Coherence Tomography

The palatine tonsils provide the first line of immune defense against foreign pathogens inhaled or ingested. However, a disruption in the epithelial layer within the tonsil crypts can lead to recurrent acute tonsillitis (RAT). Current imaging techniques suffer from poor resolution and contrast and do not allow a classification of the severity of RAT. We have developed a cross-polarized optical coherence tomography system. The system can detect a change in the polarization of the light after the light-tissue interaction. We demonstrate improved resolution and contrast in tonsil imaging with the developed method. Intensity, as well as retardance images of the excised tonsil tissue, were acquired. Features such as crypt epithelium, lymphoid follicles, and dense connective tissue were observed with improved contrast. Cross polarized optical coherence tomography can be a valuable tool in the clinic to evaluate palatine tonsils as it would allow visualizing common tonsil features without the need for any external contrast agent

Machine-Learning-Based Detecting of Eyelid Closure and Smiling Using Surface Electromyography of Auricular Muscles in Patients with Postparalytic Facial Synkinesis: A Feasibility Study

Surface electromyography (EMG) allows reliable detection of muscle activity in all nine intrinsic and extrinsic ear muscles during facial muscle movements. The ear muscles are affected by synkinetic EMG activity in patients with postparalytic facial synkinesis (PFS). The aim of the present work was to establish a machine-learning-based algorithm to detect eyelid closure and smiling in patients with PFS by recording sEMG using surface electromyography of the auricular muscles. Sixteen patients (10 female, 6 male) with PFS were included. EMG acquisition of the anterior auricular muscle, superior auricular muscle, posterior auricular muscle, tragicus muscle, orbicularis oculi muscle, and orbicularis oris muscle was performed on both sides of the face during standardized eye closure and smiling tasks. Machine-learning EMG classification with a support vector machine allowed for the reliable detection of eye closure or smiling from the ear muscle recordings with clear distinction to other mimic expressions. These results show that the EMG of the auricular muscles in patients with PFS may contain enough information to detect facial expressions to trigger a future implant in a closed-loop system for electrostimulation to improve insufficient eye closure and smiling in patients with PFS