Smart Artificial Soft Tissue - Application to a Hybrid Simulator for Training of Laryngeal Pacemaker Implantation

Surgical simulators are safe and evolving educational tools for developing surgical skills. In particular, virtual and hybrid simulators are preferred due to their detailedness, customization and evaluation capabilities. To accelerate the revolution of a novel class of hybrid simulators, a Smart Artificial Soft Tissue is presented here, that determines the relative position of conductive surgical instruments in artificial soft tissue by inverse resistance mappings without the need for a fixed reference point. This is particularly beneficial for highly deformable structures when specific target regions need to be reached or avoided. The carbon-black-silicone composite used can be shaped almost arbitrarily and its elasticity can be tuned by modifying the silicone base material. Thus, objective positional feedback for haptically correct artificial soft tissue can be ensured. This is demonstrated by the development of a laryngeal phantom to simulate the implantation of laryngeal pacemaker electrodes. Apart from the position-detecting larynx phantom, the simulator uses a tablet computer for the virtual representation of the vocal folds' movements, in accordance with the electrical stimulation by the inserted electrodes. The possibility of displaying additional information about target regions and anatomy is intended to optimize the learning progress and illustrates the extensibility of hybrid surgical simulators.

Electromyography of the posterior cricoarytenoid muscles: a consensus guideline

PURPOSE

Since the introduction of transcutaneous-transcricoidal needle approaches, electromyography (EMG) of the posterior cricoarytenoid muscle (PCA) became easier to perform and teach. Among the Neurolaryngology working group of the European Laryngological Society, several centers have adopted PCA EMG as part of their routine EMG workup in vocal fold immobility collectively gathering long-term experience. The purpose is to give an update and an extension to already existing guidelines on laryngeal EMG with specific regard to PCA EMG.

METHODS

Consensus of all co-authors is based on continuous exchange of ideas and on joint laryngeal EMG workshop experiences over at least 7 years. A Delphi method of consensus development was used, i.e., the manuscript was circulated among the co-authors until full agreement was achieved.

RESULTS

Step-by-step instructions on how to perform and interpret PCA EMG are provided.

CONCLUSIONS

Further research should include the establishment of normal values for PCA and thyroarytenoid muscle (TA) EMG as well as studies on the nature of some unusual activation pattern commonly seen in chronically lesioned PCA.

Modified vacuum-assisted closure (EndoVAC) therapy for treatment of pharyngocutaneous fistula: Case series and a review of the literature

BACKGROUND

Pharyngocutaneous fistula is a potential life-threatening complication following head and neck surgery. There is only limited evidence about the efficacy of vacuum-assisted closure (VAC) therapy and endoscopic vacuum-assisted closure (EndoVAC) therapy for the treatment of pharyngocutaneous fistulas.

METHODS

In this article, we report on a consecutive case series of six male patients with pharyngocutaneous fistula treated with a modified outside-in EndoVAC technique. We also present a review of the current related literature.

RESULTS

EndoVAC therapy alone was successful in five of the six patients (83.3%) with a median duration of EndoVAC therapy of 18.5 days (range: 7 to 32 days) and a median number of EndoVAC sponge changes of 4 (range: 1 to 9 changes). One patient needed additional reconstructive surgery after prior radiochemotherapy and jejunal transfer. No treatment-related complications were observed.

CONCLUSION

EndoVAC therapy is an easy-to-perform, safe procedure for the treatment of pharyngocutaneous fistulae.

Inter-rater reliability of seven neurolaryngologists in laryngeal EMG signal interpretation

Purpose

Laryngeal electromyography (LEMG) has been considered as gold standard in diagnostics of vocal fold movement impairment, but is still not commonly implemented in clinical routine. Since the signal interpretation of LEMG signals (LEMGs) is often a subjective and semi-quantitative matter, the goal of this study was to evaluate the inter-rater reliability of neurolaryngologists on LEMGs of volitional muscle activity.

Methods

For this study, 52 representative LEMGs of 371 LEMG datasets were selected from a multicenter registry for a blinded evaluation by 7 experienced members of the neurolaryngology working group of the European Laryngological Society (ELS). For the measurement of the observer agreement between two raters, Cohen’s Kappa statistic was calculated. For the interpretation of agreements of diagnoses among the seven examiners, we used the Fleiss’ Kappa statistic.

Result

When focusing on the categories “no activity”, “single fiber pattern”, and “strongly decreased recruitment pattern”, the inter-rater agreement varied from Cohen’s Kappa values between 0.48 and 0.84, indicating moderate to near-perfect agreement between the rater pairs. Calculating with Fleiss’ Kappa, a value of 0.61 showed good agreement among the seven raters. For the rating categories, the Fleiss’ Kappa value ranged from 0.52 to 0.74, which also showed a good agreement.

Conclusion

A good inter-rater agreement between the participating neurolaryngologists was achieved in the interpretation of LEMGs. More instructional courses should be offered to broadly implement LEMG as a reliable diagnostic tool in evaluating vocal fold movement disorders in clinical routine and to develop future algorithms for therapy and computer-assisted examination.

Therapy of bilateral vocal fold paralysis: Real world data of an international multi-center registry

Purpose

To collect data on diagnosis, treatment, patient’s management, and quality of life in patient with bilateral vocal fold paralysis (BVFP).

Methods

A retrospective, observational, multicenter registry study was performed. Medical records of 326 adults with permanent BVFP (median age: 61 years; 70% female, 60% after thyroid surgery) generated between 2010 and 2017.

Results

Median time between BVFP onset and inclusion was 1.2 years. Median post-treatment follow-up was 2 months (range: 0–42). Surgery was treatment of choice in 61.7% of the cases, with a 2-year revision rate of 32.4%. Prior to inclusion, 40.2% of the patients underwent at least one surgery. For tracheotomized patients, decannulation rate was 33.8%. Non-surgical treatments included voice therapy and botulinum toxin injection. Corticosteroid application was the most frequent treatment for post-treatment complications (18%; 1-month after surgery). Older age was an independent predictor for dyspnea (Hazard ratio [HR] = 1.041; CI = 1.005 to 1.079; p = 0.026) and the need for oxygen treatment (HR = 1.098; CI = 1.009 to 1.196; p = 0.031). Current alcohol consumption (HR = 2.565; CI = 1.232 to 5.342; p = 0.012) and a cancer-related etiology (HR = 4.767; CI = 1.615 to 14.067; p = 0.005) were independent factors of higher revision risk.

Conclusions

Surgery for BVFP is currently not standardized but highly variable. Postoperative and BVFP-related complications and revision surgery are frequent. Complications are linked to patients’ alcohol drinking habits and BVFP etiology. These results shall be confirmed by the upcoming evaluation of the prospective data of this registry.

Use of erbium laser in the treatment of persistent post-radiotherapy laryngeal edema: a case report and review of the literature

BACKGROUND

Post-radiotherapy laryngeal edema may affect the patients' quality of life, leading to repeated treatment attempts, which include massage/physical therapy, inhalations, and/or tracheostomy.

CASE PRESENTATION

We report the surgical treatment approach of a 69-year-old patient with severe persistent post-radiotherapy laryngeal edema. After multiple inpatient admissions and failed conservative therapy, we used the erbium laser to treat the arytenoid edema. After repeated procedures, no complications were observed. The patient remained free of symptoms after 30 months of follow-up.

CONCLUSIONS

The authors provide an easy-to-perform, safe, and quick surgical technique without non-severe or severe complications. Using this technique repeatedly, complications from excessive thermal damage with CO₂ laser or unpleasant solutions such as tracheostomy can be avoided.

Isolated choanal and gut atresias: pathogenetic role of serine protease inhibitor type 2 (SPINT2) gene mutations unlikely

Background

Choanal (CA) and gastrointestinal atresias (GA) are an important feature of syndromic congenital sodium diarrhea (sCSD), a disorder recently associated with mutations in the gene for serine protease inhibitor type 2 (SPINT2). It is, however, not known whether isolated non-syndromic CA and GA themselves might result from SPINT2 mutations.

Methods

We performed a prospective cohort study to investigate 19 CA and/or GA patients without diarrhea (“non-sCSD”) for potential sCSD characteristic clinical features and SPINT2 mutations.

Results

We found a heterozygous SPINT2 splice mutation (c.593-1G>A), previously demonstrated in sCSD in homozygous form, in only 1 of the 19 patients of the “non-sCSD” cohort. This patient presented with isolated anal atresia and borderline low laboratory parameters of sodium balance. In the remaining 18 non-sCSD CA/GA patients investigated, SPINT2 sequence analysis and clinical markers of sodium homeostasis were normal. None of the 188 healthy controls tested in a regional Tyrolean population harbored the c.593-1G>A mutation, which is also not listed in the ExAc and gnomAD databases.

Conclusions

The finding of only one heterozygous SPINT2 mutation in 19 patients with isolated CA/GA was not statistically significant. Therefore, SPINT2 mutations are an unlikely cause of non-sCSD atresia.

Trial registration ISRCTN73824458. Retrospectively registered 28 September 2014

A laryngealis electromyographia szerepe a hangszalag-mozgászavarok diagnosztikájában és az alkalmazott kezelés kiválasztásában

Abstract:

The development of the therapeutic possibilities of vocal cord immobility necessitated the parallel renewal of diagnostic methods. In the last years, laryngeal electromyography, which was first introduced more than 70 years ago, has been re-discovered. After reviewing the international literature and their own experience, the authors present the indications, technical requirements, method and, particularly, the evaluation of the results of this procedure. Laryngeal electromyography makes the differentiation between mechanical fixation and immobility with neurological origin of the vocal folds possible. In case of laryngeal paralysis/paresis it also evaluates objectively the severity of neural injury, the prognosis of the disease and the necessity of any glottis-widening procedure. The widespread application of dynamic rehabilitation interventions is not conceivable without the routine application of laryngeal electromyography, so this sensitive diagnostic tool has to be introduced in all laryngological centers. Orv Hetil. 2018; 159(8): 303–311.

Laryngeal pacing for bilateral vocal fold paralysis: Voice and respiratory aspects

OBJECTIVE

To evaluate the effects of neurostimulation with the laryngeal pacemaker (LP) system in patients with bilateral vocal fold paralysis (BVFP) in terms of voice quality and respiratory function.

STUDY DESIGN

Feasibility study, first-in-human, single-arm, open-label, prospective, multicenter study with group-sequential design and 6-month follow-up period, as described in details in our previous publication.

METHODS

Nine symptomatic BVFP subjects were unilaterally implanted with the LP system at three study sites in Germany and Austria. Subjective and objective voice function, spirometric parameters other than peak expiratory/inspiratory flow (PEF/PIF), and PEF-meter self-assessment were evaluated pre- and 6 months postimplantation.

RESULTS

In general, the LP system did not considerably change the voice quality of the implanted patients. Only the sound pressure level range improved significantly 6 months postimplantation (P = 0.018). The LP system implantation did not affect the glottal closure configuration, the duration of the closed phase, and the mucosal wave of the implanted side. The evaluated spirometric parameters were not significantly affected by laryngeal pacing, whereas PEF meter self-assessment showed a stable and significant (P = 0.028) improvement of the PEF within a week upon activation of the LP system.

CONCLUSION

Neurostimulation with the LP system results in an immediate and stable PEF improvement, without negative effects on the voice quality. The PEF meter self-assessment confirmed the spirometry results of the PEF. The stimulated abduction did not affect the glottal closure during phonation. These results should be confirmed in larger and more homogenous patient cohorts.

LEVEL OF EVIDENCE

2b Laryngoscope, 127:1838-1844, 2017.

Laryngeal pacing via an implantable stimulator for the rehabilitation of subjects suffering from bilateral vocal fold paralysis: A prospective first-in-human study

OBJECTIVES/HYPOTHESIS

To evaluate the performance and safety of the newly developed Laryngeal Pacemaker System (LP System) for the treatment of bilateral vocal fold paralysis (BVFP).

STUDY DESIGN

Feasibility, first-in-human, single-arm, open-label, prospective, multicenter study with a group sequential design and a 6-month follow-up period.

METHODS

Nine symptomatic BVFP subjects were implanted unilaterally with the LP System. Pre- and 6-month postimplantation evaluations consisted of the 6-Minute Walk Test (6MWT), the Peak Expiratory and Inspiratory Flow (PEF and PIF) evaluation, the PEF meter analysis, the 36-Item Short Form Health Survey (SF-36), the Glasgow Benefit Inventory (GBI), the 12-Item Voice Handicap Index (VHI-12), and the Fiberoptic Endoscopic Evaluation of Swallowing. The safety profile of the LP System was continuously monitored.

RESULTS

The LP System implantation was achieved in 8/9 cases. Seven of the nine subjects completed the study. Absolute PEF and PIF values improved significantly 6 months postimplantation (P < .05). 6MWT results showed a non-statistically significant improvement (P = .09). The mental component of the SF-36 showed a significant improvement (P = .043), whereas the other SF-36 components, the GBI, and the VHI-12 results did not changed significantly. The LP System did not affect the voice and swallowing quality and maintained a reliable safety profile for the duration of the study.

CONCLUSIONS

This feasibility study showed that the LP System has the potential to become an effective and safe treatment for BVFP subjects without compromising the patients' voice.

LEVEL OF EVIDENCE

2b Laryngoscope, 126:1810-1816, 2016.

Refractory rhinosinusitis complicating immunosuppression: application of N-chlorotaurine, a novel endogenous antiseptic agent

Severe infections are a frequent complication in immunosuppression following transplantations. In the case reported here, a heart-transplanted patient was treated for refractory rhinosinusitis with a combination of sinus surgery and rinsing with N-chlorotaurine (NCT). The daily rinse was well tolerated and effective. The combination of functional endonasal sinus surgery and topical treatment with NCT appeared effective and well tolerated in antibiotic-resistant sinusitis under immunosuppression.

[Viability monitor of free flaps in hypopharynx reconstruction]

Single-stage microvascular reconstruction of neck defects with jejunum or other free flaps are well established methods. However, these flaps usually are buried subcutaneously and viability surveillance is difficult. Alternatively to technical monitoring devices, we present a simple method using a "sentinel" part of the free jejunum flap transposed outside to the skin surface or sutured into the skin when using fasciocutaneous or myocutaneous flaps. Although this method is not new, it is rarely used. Compared to pure technical monitoring devices, it is easily performed and monitoring of buried free flaps especially in the neck region is reliable.

Transnasal treatment of congenital choanal atresia with the KTP laser

This retrospective analysis presents a minimally invasive method for a transnasal approach to treat bilateral and unilateral choanal atresia and stenosis in infants and children. We describe an advanced surgical technique that applies the use of a KTP laser and give recommendations for preoperative diagnosis and postoperative assessment. We report 13 cases of bilateral and unilateral choanal atresia or stenosis treated over a 3 1/2-year period. We used a transnasal approach and endoscopic control. For bilateral choanal atresia, the operation was performed within the first few days of birth. For unilateral choanal atresia or stenosis, surgery was performed several weeks after birth. In all cases, an intranasal stent was inserted. Our findings demonstrate that this transnasal approach provides significant benefits. A primary advantage is the diminished risk of intraoperative or postoperative complications. Additional benefits include lower rates of re-obstruction and a decreased incidence of subsequent disease, including chronic secretory otitis media.

Textured polydimethylsiloxane elastomers in the human larynx: safety and efficiency of use

For the treatment of unilateral laryngeal paralysis with glottic insufficiency injection laryngoplasty is a popular modality of treatment. This procedure augments the volume of the paralyzed vocal fold by endoscopic injection. However, the ideal substance has not yet been found for that purpose. We report for the first time the systematic application and long-term results of vulcanized polydimethylsiloxane (PDMS) particles in the treatment of glottic insufficiency in the human larynx. Of 10 patients treated with PDMS in the early 1990s, 7 patients could be retrieved for reevaluation. Laryngeal function was assessed by videostroboscopy, expert rating, and further characterized by the objective parameters of voice profile and maximum phonation time. In a standardized questionnaire, all patients were asked for their personal impression of the results. Mean follow-up time was 88.4 months (range 69-102 months). Glottic closure was complete in 5 of 7 patients. There were no signs of granuloma formation or other pathologic changes of the injected vocal folds. In 4 cases, voices were rated normal or near-normal; 2 voices were rated as fair; 1 usable. All the patients reported significant and lasting voice improvement. None of the patients reported any problems related to PDMS. PDMS particles provide permanent augmentation of human vocal fold volume without complications. Their use is a valuable and safe alternative when a definitive one-step procedure seems advantageous. However, further studies are needed to assess voice improvement in comparison to other materials.

Rare benign tumors: laryngeal and hypopharyngeal lipomata

Lipomata of the larynx and the hypopharynx are very rare benign lesions; as they look macroscopically like retention cysts, their diagnosis is usually made after surgery. Sometimes, lipomata of the hypopharynx become very large and life-threatening. Plain fluoroscopy and fluoroscopy aided with barium often fail to depict the lesion if it is localized subepiglottically; standard barium swallow examination and computed tomography allow an accurate diagnosis to be made in many cases, although magnetic resonance imaging is still more accurate and allows not only a more specific diagnosis of the lesion, but also a better depiction of the origin of the frequently pedunculated tumor and its extension into the parapharyngeal space. This paper adds 6 cases of hypopharyngeal and 1 case of laryngeal lipoma to the literature and discusses modern diagnostic and therapeutic strategies.

Morphometric measurements of the cartilaginous larynx: An anatomic correlate of laryngeal surgery

BACKGROUND

The increasing application of sophisticated methods of laryngeal framework surgery requires a profound knowledge of the size and proportions of the human larynx and its cartilaginous components. Only inadequate data regarding this subject have so far been accessible. The aim of this study was to collect exact and reliable morphometric data of the human laryngeal framework. Materials and Methods Larynges from 98 corpses (52 male, 46 female) were removed during autopsy 4-64 hours postmortem and processed without delay or fixation. Following a standard routine for preparation, 28 parameters were measured on thyroid cartilage, cricoid cartilage, arytenoid cartilage, epiglottis, and the larynx as a whole organ. None of the patients had histories or visible signs of laryngeal disease. Anatomical preparations were performed with customary surgical tools and morphometric measurements then carried out with a pair of compasses and a caliper rule.

RESULTS

A total of 5,100 measurements was performed on 98 larynges. These included, aside from evaluation of the whole organ, identification of the internal and external diameters of the cricoid cartilage, height and length of the thyroid alae in different planes, angle of thyroid alae, height of arytenoid cartilage, width and length of epiglottic cartilage, and position of the anterior commissure related to the thyroid cartilage. The results provide a full scale of data determining the size and extent not only of the cartilaginous components, but of the laryngeal framework as a whole. Mean values, standard deviations, and sample sizes are given for every parameter separately for both sexes.

CONCLUSION

This study provides a comprehensive and detailed description of the dimensions of the adult human larynx.

Morphology of the human larynx during the first five years of life studied on whole organ serial sections

The morphologic development of the human larynx during the first years of life is poorly understood to date. This study used plastinated whole organ serial sections to determine the growth and structure of the infant larynx. The larynges of 43 children 1 to 60 months old were plastinated. Whole organ serial sections were obtained by cutting the resulting specimen with a diamond band saw. The slices were then submitted to computer-assisted morphometric investigation. We found that the subglottic airway rapidly increases in size during the first 2 years of life. Further growth follows a linear mode. The relative proportion of the mucosal lining decreases likewise. In contrast to that in adults, and comparable to that in most mammals, the cartilaginous glottis accounts for 60% to 75% of the vocal folds' length at <2 years. No sexual dimorphism of the larynx exists during childhood. This study supplies detailed morphometric data on the growth and structure of the human larynx during the first years of life. It is the first to use plastinated whole organ serial sections for morphology of the pediatric larynx. Therefore, this study provides quantitative anatomic data of clinical interest that have not been available to date.

[Voice quality after partial laser laryngectomy]

BACKGROUND

We conducted a prospective study to investigate voice quality after transoral endolaryngeal laser surgery in terms of ability to communicate effectively. Eighty patients with T1 or T2 glottic carcinoma were enrolled in the study. The main objective was to identify the influence of type and extent of surgery on postoperative voice parameters after endoscopic laser surgery.

MATERIAL AND METHODS

The postoperative mechanism of phonation was assessed by videostroboscopy six months after surgery at the earliest. A phonetogram was produced and its area calculated (relative phonetogram, RP) in relation to a gender-specific normal phonetogram. A speech therapist (ST) and a trained otolaryngologist (TO) rated each voice independently for communication ability in a grade from 1 (poor) to 6 (near normal).

RESULTS

After simple cordectomy the mean values were as follows: RP = 24.8%, TO = 3.26, ST = 3.33. When the anterior commissure was completely preserved mean results were better (RP = 34%, TO = 3.92, ST = 3.83). Results were worse following extended cordectomy (RP = 14.7%, TO = 2.82, ST = 3.00) and transglottic resection (RP = 13.7%, TO = 2.30, ST = 2.86), but similar within these two groups. The parameters RP, TO, and ST do not differ significantly between the group who had speech therapy after surgery (N = 33) and the group who did not (N = 47). Voice production at glottic level yields better results for every parameter than supraglottic substitute phonation. The amount of tissue removed was less significant.

CONCLUSION

We conclude that postoperative phonatory results correlate with the postoperative mechanism of phonation. There is no linear correlation with the amount of tissue removed. Comparing similar types of resection preservation of the anterior commissure plays a key role. From the data in this study there is no evidence of a significant benefit from speech therapy. The parameter RP is an effective and relatively simple parameter to complete auditive voice assessment.

[Virtual endoscopy with post-processing helical CT data sets]

PURPOSE

The purpose of this work was to test a newly developed, post-processing software for virtual CT endoscopic methods. Virtual endoscopic images were generated from helical CT data sets in the region of the shoulder joint (n = 2), the tracheobronchial system (n = 3), the nasal sinuses (n = 2), the colon (n = 2), and the common carotid artery n = 1). Software developed specifically for virtual endoscopy ("Navigator") was used which, after a previous threshold value selection, makes the reconstruction of internal body surfaces possible by an automatic segmentation process. We have evaluated the usage of the software, the reconstruction time for individual images and sequences of images as well as the quality of the reconstruction. All pathological findings of the virtual endoscopy were confirmed by surgery.

RESULTS

The post-processing program is easy to use and provides virtual endoscopic images within 50 seconds. Depending of the extent of the data set, virtual tracheobronchoscopy as a cine loop sequence required about 15 minutes. Through use of the threshold value-dependent surface reconstruction the demands on the computer configuration are limited; however, this also created quality problems in image calculation as a consequence of the accompanying loss of data.

CONCLUSIONS

The Navigator software enables the calculation of virtual endoscopic models with only moderate demands on the hardware.

Electromyographic evaluation of vocal cord disorders

In order to perform its basic functions, those of coordination of breathing, swallowing and speech, the larynx requires an intact neural apparatus to permit the perfect, well-coordinated action of the neuromuscular structures of extra- and intralaryngeal muscles. Electrophysiological measurements including electromyography, reflexmyography, electric and magnetic stimulated myography of the central motor nerve functions are the methods of classification of dysfunctions into neurapraxia, axonotmesis, neurotmesis, regeneration or myopathy. Different types of electrodes, depending on the methods of application, show a variety of neurophysiological findings which allow the investigator to decide about the type of lesion. An overview on neurophysiological techniques in vocal cord disorders is presented.

[Using a rotating suction debridement instrument with power generator in endonasal paranasal sinus surgery]

Endonasal nasal and sinus surgery using an endoscope for visual control has minimized the risks of surgery. A new technique is presented in which a suction-irrigation endoscope is used for visual control during surgery. The instrument is combined with a suction-rotation microdebrider with different tips and a power generator. The handling of this instrument is easy and atraumatic and it achieves a relatively bloodless field to reduce further the risk of inadvertent penetration of the skull base and lamina papyracea during endoscopic surgery.

Complete sphenoethmoidectomy and computer-assisted surgery

Many surgical procedures in the field of ENT take place in close proximity to vital structures like the orbit, the skull base, the internal carotid artery etc. In our clinic we have decided to study two different computer-assisted navigation systems to reduce the risk of trauma to these structures during endonasal endoscopic procedures. Such systems should be able to correlate the position of the surgical instrument, ideally in the submillimeter range, to CT- or MR-images. The ARTMA Virtual Patient finds the position of the instrument by permanently measuring magnetic fields. The ISG-system uses a mechanical arm to localize the probe in the patient. Using Computer-Assisted-Surgery (CAS) does not significantly extend the time needed for surgery. We found that it prevents the surgeon from inadvertently injuring structures. Other groups have shown (1) that CAS-systems minimize the risk of complications of surgical procedures in the frontobasis arising from mishaps in the usage of the endoscope or the surgical tool. If properly used, CAS-systems can be a very helpful tool in the hand of an experienced surgeon but will never replace his expertise and knowledge.

Transoral laser resection with staged discontinuous neck dissection for oral cavity and oropharynx squamous cell carcinoma

Transoral laser resection of oral cavity and oropharynx squamous cell carcinoma (OOSCC) is a widely accepted approach in the absence of cervical lymph node metastases. This study investigated the results of transoral laser surgery and discontinuous neck dissection (ND) for OOSCC with clinically obvious or suspected cervical node metastases. One hundred seventeen patients with infiltrating oral carcinoma were treated for cure with transoral resection of the primary and staged ND. Twenty-nine primaries were classified as T1, 50 as T2, 35 as T3, and 3 as T4. Lymph node metastases were identified in the ND specimen of 36 patients. All patients were followed for a minimum of 3 years unless they died. Estimated tumor-related survival after 5 years is 81% for stage I and II disease of the oral cavity, 86% for stage I and II disease of the oropharynx, 73% for stage III disease of the oral cavity, 65% for stage III disease of the oropharynx, and 21% for stage IV disease of the oral cavity and the oropharynx. Local and regional control of cancer was achieved in 72 (62%) of the 117 patients. Forty-five local and regional recurrences were diagnosed during the follow-up period. Two patients died of distant metastases with no evidence of local or regional recurrence. The combination of transoral laser resection and staged ND for the treatment of OOSCC seems to offer satisfactory cure rates for a selected group of patients. These two minor surgical interventions cause less morbidity than commando-type surgery and lead to low perioperative mortality and morbidity.

Treatment of dysfunction of the cricopharyngeal muscle with botulinum A toxin: introduction of a new, noninvasive method

Botulinum toxin is known as a relatively safe and efficacious agent for the treatment of various neurologic and ophthalmologic disorders. Since dysphagia and deglutition problems combined with aspiration are often caused by spasticity, hypertonus, or delayed relaxation of the upper esophageal sphincter (UES), conventional treatment including lateral cricopharyngotomy was replaced by localized injections of botulinum toxin into the cricopharyngeal muscle (CM) in a series of 7 patients. The study comprised patients with slight dysphagia caused by isolated hypertonus of the UES, as well as patients with severe deglutition disorders, complete inability to swallow, and aspiration problems. Preoperative diagnostic evaluation included careful history-taking, physical examination, cineradiography, and esophageal manometry to exclude other causes of dysphagia. For precise localization, injections were performed under general anesthesia after location of the CM by direct esophagoscopy and electromyographic guidance. Injections were administered into the dorsomedial part and on both sides into the ventrolateral parts of the muscle. Depending on the severity of symptoms and the intraluminal pressure of the UES, the dose varied between 80 and 120 units (botulinum toxin A from Dysport). The treatment outcome was evaluated by a disability rating score: patients' complaints were scored by subjective and objective parameters before and after injection. All but 2 patients experienced complete relief or marked improvement of their complaints. There were no severe side effects or postoperative complications. Local botulinum toxin injection proved to be an effective alternative treatment to invasive procedures for patients with isolated dysfunction of the UES, and also for patients with more complex deglutition problems combined with aspiration.

Electrophysiologic investigation of lower cranial nerve diseases by means of magnetically stimulated neuromyography of the larynx

Zoom endoscopic electromyography of the larynx, as introduced in 1979, has contributed greatly to the diagnosis of lower cranial nerve palsies, but in the early stage of a vagus nerve disorder one cannot investigate the nerve conduction from the brain stem to the laryngeal muscles with electrical stimulation. As with the early diagnosis of facial nerve palsies, up to now the intracranial part of the motoric brain nerves could not be stimulated directly. With a new magnetic coil device (Novametrix, Magstim 200) this intracranial stimulation is easily possible in the awake patient with painless magnetic stimuli that induce a muscle action potential into the laryngeal muscles. Hence, an immediate diagnosis is possible. Two coils with mean diameters of 8.5 or 3 cm were used. The stimulator delivered current pulses of peak amplitude up to 5,000 A with rise times of 140 microseconds and 65 microseconds, respectively, that generated peak fields of up to 2 T. In a healthy population, cisternal stimulation of the vagus nerve leads to a muscular response in the vocal muscle after 4 to 6.6 milliseconds (mean 5 milliseconds). Cortical stimulation leads to such a response after 9.5 to 12 milliseconds. Potentials in healthy individuals have been shown to be very uniform. Stimulation in recurrent nerve palsies may show prolongation of these latencies up to 30 milliseconds. The method is limited by the fact that complete neural blocks cannot be overcome by proximal stimulation. We have applied magnetic stimulation to 190 patients with different disorders of the vagus nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

[Automated assessment of cranial nerve paralyses using computerized electromyography]

Until the formulae of Lindstrom et al. the automatic analysis of electromyograms had no empirical basis in the differentiation of neurapraxia and degenerative paralysis. The EMG-analysis computer program modified by Berg et al. was used for the evaluation of average power spectra derived with a Fast Fourier transformation on 37 patients with known neurapraxia and 54 with proven degeneration. In order to work out a characteristic function we calculated average power spectra separately for each type of paralysis (facial or laryngeal muscles). The resulting spectrum configurations and their absolute values (root-mean-square and central frequency) were compared, and their value in automated EMG analysis was analysed. The results provide a basis for the routine use of the computer program in routine clinical diagnosis.