Automated surgery planning for an obstructed nose by combining computational fluid dynamics with reinforcement learning

Septoplasty and turbinectomy are among the most common interventions in the field of rhinology. Their constantly debated success rates and the lack of quantitative flow data of the entire nasal airway for planning the surgery necessitate methodological improvement. Thus, physics-based surgery planning is highly desirable. In this work, a novel and accurate method is developed to enhance surgery planning by physical aspects of respiration, i.e., to plan anti-obstructive surgery, for the first time a reinforcement learning algorithm is combined with large-scale computational fluid dynamics simulations. The method is integrated into an automated pipeline based on computed tomography imaging. The proposed surgical intervention is compared to a surgeon's initial plan, or the maximum possible intervention, which allows the quantitative evaluation of the intended surgery. Two criteria are considered: (i) the capability to supply the nasal airway with air expressed by the pressure loss and (ii) the capability to heat incoming air represented by the temperature increase. For a test patient suffering from a deviated septum near the nostrils and a bony spur further downstream, the method recommends surgical interventions exactly at these locations. For equal weights on the two criteria (i) and (ii), the algorithm proposes a slightly weaker correction of the deviated septum at the first location, compared to the surgeon's plan. At the second location, the algorithm proposes to keep the bony spur. For a larger weight on criterion (i), the algorithm tends to widen the nasal passage by removing the bony spur. For a larger weight on criterion (ii), the algorithm's suggestion approaches the pre-surgical state with narrowed channels that favor heat transfer. A second patient is investigated that suffers from enlarged turbinates in the left nasal passage. For equal weights on the two criteria (i) and (ii), the algorithm proposes a nearly complete removal of the inferior turbinate, and a moderate reduction of the middle turbinate. An increased weight on criterion (i) leads to an additional reduction of the middle turbinate, and a larger weight on criterion (ii) yields a solution with only slight reductions of both turbinates, i.e., focusing on a sufficient heat exchange between incoming air and the air-nose interface. The proposed method has the potential to improve the success rates of the aforementioned surgeries and can be extended to further biomedical flows.

[Management of ear, nose and throat emergencies]

Emergency situations involving the ears, nose, and throat (ENT) area can pose considerable challenges for clinicians and often require an interdisciplinary approach due to the involvement of different organ systems. To avoid damage to highly relevant sensory and perception organs and life-threatening bleeding or respiratory complications, strategies that are as quick and targeted as possible are necessary. This article aims to provide an overview of ENT emergency management strategies. The entire spectrum from simple conservative to highly complex surgical measures plays a role here, both diagnostically and therapeutically. Aspects such as bleeding, respiratory problems, inflammation, hearing disorders, vertigo, facial palsy and injuries to the head and neck area are discussed. In addition, important topics such as preventive measures and possible complications are also addressed to ensure optimal patient care.

[Neuroendocrine tumors in head and neck]

INTRODUCTION

NETs are benign or malign tumors, which originate from cells of the endocrine (hormonal) and nervous systems. 0,5-2 % of the neoplasms are neuroendocrine tumors, which are mostly located in the gastrointestinal or bronchopulmonal tract. Die incidence is about 9000/100000. 1% of the head and neck tumors are NET. This study evaluates NETs with different locations, its therapy and outcome.

METHODS

14 patients with a neuroendocrine tumor of the head and neck between 2010 and 2017 were evaluated. 8 patients underwent an operation and adjuvant radiochemotherapy (RCT). Five patients had a prim. RCT with curative intention. One patient had a palliative chemotherapy because of the progress after the radiochemotherapy.

RESULTS

The locations of the tumors are the larynx (n=7), parotid gland (n=2) and the paranasal sinuses (n=5). A resection in sano (R0) could be reached in 6 of 8 cases. The average survival rate was 19±6 months. 2 tumor recurrences occurred out of 14 patients. 1 patient died after 7 months und 1 patient is without recurrence after 32 months. 2 patients had no benefit of the combined radiochemotherapy and died after 6 and 13 months. Die overall survival depends on the stage and the R0 resection of the tumors. The R0 resection is better in comparison to the prim. According to the overall survival time CONCLUSION: Patients with NET of the head and neck have to be treated in specialized cancer centers. Each patient should receive an individual therapy depending on localization and histopathtological findings.

[Current developments in primary and secondary surgical treatment of midface and periorbital trauma]

Fractures of the periorbita and the midface are among the most common bony facial injuries. Aesthetic and functional reconstruction is a challenge in clinical routine. This article illustrates recent developments in the primary and secondary surgical treatment of midface and periorbital trauma. Resorbable patches and films increase the anatomic reconstructive capacity and enable treatment of extensive orbital fractures. Orbital fractures with involvement of supporting key structures are advantageously reconstructed using patient-specific implants (PSI), which are fabricated by computer-assisted manufacturing techniques and positioned by intraoperative navigation. If late complications such as bulbar malposition and enophthalmos have occurred after the initial procedure, they can be addressed by overcorrective restoration of orbital volume. The use of PSI for initial fracture restoration of the midface is not yet established but may be useful in re-osteotomies of misconsolidated fragments. Extensive midface defects with significant soft tissue involvement can be reconstructed using microvascular grafts. Consecutive reconstructive procedures may include orthognathic surgery and local flap reconstruction. In summary, the integration and advancement of computer-assisted techniques now offers individualized reconstruction procedures, which may be a viable alternative to conventional implants and compression miniplates. Future developments may focus on the search for innovative biomaterials, which can be integrated into computer-aided design and manufacturing processes.

Olfactory functioning in adults with Tourette syndrome

Tourette syndrome is a chronic tic disorder characterized by motor and vocal tics. Comorbidities such as attention deficit hyperactivity disorder and obsessive compulsive disorder can be found. The overlap between neuroanatomical regions and neurotransmitter systems in the olfactory system and the pathophysiology of Tourette syndrome let us hypothesize altered olfactory performance in Tourette syndrome. The main objective of this study was to systematically assess olfactory functioning in subjects with Tourette syndrome and to compare it to healthy controls. We assessed 28 adults with Tourette syndrome (age 33.1±9.4 years, disease duration 23.7±9.7 years) and 28 healthy controls (age 32.9±9.0 years) matched in regard to age, sex, education and smoking habits. The “Sniffin Sticks” test battery was applied to assess odor threshold, discrimination, and identification. Additionally, the combined score of the odor threshold test, the odor discrimination test and the odor identification test of the “Sniffin Sticks” test battery was calculated. Although it was not the primary aim of this study, we assessed whether tics and comorbidity could contribute to olfactory alterations in adults with Tourette syndrome. Therefore, clinical scores were used to assess severity of tics and co-morbidity such as attention deficit hyperactivity disorder, obsessive compulsive disorder, anxiety and depression in subjects with Tourette syndrome. Pathology of the nasal cavities was excluded with rhinoendoscopy. Independent sample t-tests were applied to compare performance in olfactory tests. In the case of statistically significant differences (critical p-value: 0.05), multiple linear regression analysis was carried out to explore whether tic severity, social impairment, co-morbidity or medical treatment had an impact on the differences found. Descriptive values are reported as mean ± standard deviation. Tourette syndrome subjects showed lower combined scores (Tourette syndrome subjects 31.9 ± 5.1 versus healthy controls 35.0 ± 3.1; p = 0.007), odor identification scores (Tourette syndrome subjects 12.4 ± 2.0 versus healthy controls 13.7 ± 1.4; p = 0.008) and odor discrimination scores (Tourette syndrome subjects 12.1 ± 2.1 versus healthy controls 13.2 ± 1.6; p = 0.041) in comparison to healthy subjects, while there was no difference in odor threshold (Tourette syndrome subjects 7.3 ± 2.7 versus healthy controls 8.1 ± 2.2; p = 0.22). Seven out of 28 Tourette syndrome subjects (25%) scored in the range of the age- and sex-dependent combined score for hyposmia, while two of 28 healthy controls (7%) had a similar low combined score. None of the participants were found to have functional anosmia. Multiple linear regression analyses suggest that social impairment may a predictor for low combined score and odor identification score in Tourette syndrome subjects (p = 0.003). Compared to healthy controls, altered olfaction in adults with Tourette syndrome was found in this study. Normal odor threshold level but lower scores at tasks involving supra-threshold odor concentrations point towards a central-nervous alteration in the processing of olfactory information in Tourette syndrome.

Cinnarizine and dimenhydrinate in the treatment of vertigo in medical practice

The efficacy and safety of the fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg in the treatment of vertigo of various origins have been investigated in a prospective, noninterventional study involving private practices throughout Germany. A total of 1275 patients with an average age of 61.2 years participated in the study. The vertigo symptoms, measured by a validated mean vertigo score (primary efficacy endpoint) improved by 61 % in the course of the observational period (median: 6 weeks). Concomitant symptoms frequently associated with vertigo such as nausea, vomiting and tinnitus were also markedly reduced by 84, 85 and 51 %, respectively. Overall efficacy has been rated by the physicians as 'very much improved' or 'much improved' in 95 % of the patients. A total of 47 patients (3.7 %) reported 51 adverse drug reactions (all nonserious). The results indicate a good tolerability and efficacy of the fixed combination of cinnarizine and dimenhydrinate in the treatment of vertigo in daily medical practice, which is in line with previous findings of numerous interventional, randomised, double-blind, controlled clinical trials.

[Marketing issues for the otorhinolaryngologist]

BACKGROUND

Economic aspects related to the German health care system are rising. In the outpatient area does this trend influence the organization of the surgery and the treatment procedures as well as the relationship between the patient and the doctor. The patient's free volition of choice is increasing and the patient becomes a "customer" in the health system. The aim of this work is to to elucidate marketing issues for otorhinolaryngologist, which could improve the efficiency of their surgery.

MATERIAL AND METHODS

150 otorhinolaryngologist have undergone a written survey. The subjects of this survey were, how far marketing strategies are used by otolaryngologists and on the other hand, what are their opinions on marketing.

RESULTS

115 returned questionnaires were included in the statistical analysis (response rate: 77%). Only 44% of surveyed otolaryngologists deal yet with economic aspects. After all, 65% of the otorhinolaryngologist offered individual health services. On the other hand only 51% of otolaryngologists were additionaly qualificated and only 14% would like to acquire more skills. At the time of the survey 78% conducted a homepage.

CONCLUSION

This study examined for the first time economic aspect in an otorhinolaryngology outpatient clinic. The interest in economic processes is currently low, but required by German law and in the interest of the owner himself. The 4 pillars of traditional marketing research help to understand the practice economically viable easily and competitive to set up in local contests over a long period.

Vestibular rehabilitation using the Nintendo® Wii Balance Board -- a user-friendly alternative for central nervous compensation

CONCLUSION

The Nintendo® Wii Balance Board is a cost-effective and user-friendly alternative to other popular frequently used systems that aid vestibular compensation, particularly in elderly patients. In addition, further treatment in the home environment is possible.

OBJECTIVE

This cohort study was designed to investigate the impact of the Nintendo® Wii Balance Board as a visual compensation device after acute vestibular neuritis.

METHODS

Subjects were randomly assigned to one of two treatment groups. Group A (n = 37) performed customized exercises with the Nintendo® Wii Balance Board. Group B (n = 34) performed only two elected exercises as a control group for comparison of the results. Both groups underwent additive therapy with steroids (intravenous) in decreasing doses (250 mg decreasing to 25 mg over 10 days). The Sensory Organization Test (SOT), Dizziness Handicap Inventory (DHI), Vertigo Symptom Scale (VSS), and Tinneti questionnaire were evaluated immediately before treatment (baseline), at the end of treatment, i.e. at day 5, and after 10 weeks.

RESULTS

The early use of a visual feedback system in the context of the balance training supports the central nervous vestibular compensation after peripheral labyrinthine disorders. Patients in group B (without training) required a longer in-patient stay (average 2.4 days, SD 0.4) compared with patients following early Wii rehabilitation. The absence of nystagmus under Frenzel's goggles in group A was observed 2.1 days (SD 0.5) earlier than in group B. Group A showed significantly better results in the SOT, DHI, VSS, and Tinneti questionnaire at all time points measured (p < 0.05).

Involvement of the human ventrolateral thalamus in olfaction

It is widely assumed that the thalamus is not involved in olfaction. The ventrolateral thalamus is, however, closely connected to the contralateral cerebellum, which is involved in the sense of smell based on findings from functional imaging studies and findings of olfactory deficits in patients with cerebellar disease. We hypothesized that olfactory deficits following lesions of the ventrolateral thalamus may be similar to olfactory deficits following cerebellar lesions. Fifteen patients with a focal thalamic lesion involving the ventrolateral thalamus were examined and compared to 15 patients with a focal cerebellar lesion and 15 healthy controls. A detailed olfactory test ("Sniffin' Sticks") was used to assess different olfactory functions separately for each nostril. In the group of patients with a lesion of the ventrolateral thalamus, an impairment of the odor threshold was found at the ipsilateral nostril, consistent with the unilateral orientation of the olfactory system in the telencephalon. In the group of patients with a cerebellar lesion, an olfactory deficit at the contralesional nostril emerged. In controls, no significant side difference was found. The involvement of the ventrolateral thalamus in olfaction is comparable to that of the cerebellum in respect to odor threshold. Further study is needed to assess if these findings are related to an impairment of an olfactomotor loop. Present evidence for this hypothesis is indirect. Effects were subclinical as none of the patients reported olfactory disturbance. The results suggest that the cerebello-thalamic axis plays an adjuvant role in olfaction.

Free-text data entry by speech recognition software and its impact on clinical routine

We conducted a study to evaluate speech recognition software in an otorhinolaryngology unit and to assess its impact on productivity prior to general implementation. Current speech recognition software (IBM ViaVoice, version 10) was implemented on a personal computer with a 2-GHz central processing unit, 256 MB of RAM, and a 30-GB hard disk drive, with and without add-on professional vocabulary for otorhinolaryngology. This vocabulary was added by the automated analysis of an additional 12,257 documents from our department. We compared the word recognition error rates for three different text types and determined their impact on the amount of surgeon's time that was invested in the production of an error-free document. Although error rates without any professional vocabulary database were rather high (operation reports: 38.72%; consultation notes: 27.77%), the patient information was edited with a satisfactory result (10.65%). Best results were obtained with the specialty-related vocabulary database added by the analysis of our own documents (operation reports: 5.45%; consultation notes: 5.21%). An increase in productivity compared with that of conventional transcription was found at an error rate of less than 16%.

Free-Text Data Entry by Speech Recognition Software and its Impact on Clinical Routine

We conducted a study to evaluate speech recognition software in an otorhiriolaryngology unit and to assess its impact on productivity prior to general implementation. Current speech recognition software (IBM ViaVoice, version 10) was implemented on a personal computer with a 2-GHz central processing unit, 256 MB of RAM, and a 30-GB hard disk drive, with and without add-on professional vocabulary for otorhinolaryngology. This vocabulary was added by the automated analysis of an additional 12,257 documents from our department. We compared the word recognition error rates for three different text types and determined their impact on the amount of surgeon's time that was invested in the production of an error-free document. Although error rates without any professional vocabulary database were rather high (operation reports: 38.72%; consultation notes: 27.77%), the patient information was edited with a satisfactory result (10.65%). Best results were obtained with the specialty-related vocabulary database added by the analysis of our own documents (operation reports: 5.45%; consultation notes: 5.21%). An increase in productivity compared with that of conventional transcription was found at an error rate of less than 16%.

[Infectious mononucleosis]

The primary infection with Epstein-Barr virus in an immunocompetent individual leads to infectious mononucleosis with symptoms of diphtheroid angina, lymph node swelling in the neck and hepatosplenomegaly. The most common age of infection lies between 15 and 25 years. The illness can affect a number of organs simultaneously and thus requires interdisciplinary diagnostics. For differential diagnosis, a differential blood analysis and a EBV quick test are required. The presence of IgM antibodies demonstrates the presence of the infection. Ultrasound of the abdomen can be made to determine the involvement of additional organs. In most cases, recovery occurs without complications. Acute cases can usually be handled successfully with medication. If symptomatic treatment fails, pharyngeal airway obstruction is possible and a tonsillectomy may be necessary. Otherwise, surgical treatment is obsolete. Generally, the prognosis is good. Severe courses and complications are rare.

Morphological effects of nanosecond- and femtosecond-pulsed laser ablation on human middle ear ossicles

We evaluate the feasibility of nanosecond-pulsed and femtosecond-pulsed lasers for otologic surgery. The outcome parameters are cutting precision (in micrometers), ablation rate (in micrometers per second), scanning speed (in millimeters per second), and morphological effects on human middle ear ossicles. We examine single-spot ablations by a nanosecond-pulsed, frequency-tripled Nd:YAG laser (355 nm, beam diameter 10 microm, pulse rate 2 kHz, power 250 mW) on isolated human mallei. A similar system (355 nm, beam diameter 20 microm, pulse rate 10 kHz, power 160-1500 mW) and a femtosecond-pulsed CrLi:SAF-Laser (850 nm, pulse duration 100 fs, pulse energy 40 microJ, beam diameter 36 microm, pulse rate 1 kHz) are coupled to a scanner to perform bone surface ablation over a defined area. In our setups 1 and 2, marginal carbonization is visible in all single-spot ablations of 1-s exposures and longer: With an exposure time of 0.5 s, precise cutting margins without carbonization are observed. Cooling with saline solution result is in no carbonization at 1500 mW and a scan speed of 500 mms. Our third setup shows no carbonization but greater cutting precision, although the ablation volume is lower. Nanosecond- and femtosecond-pulsed laser systems bear the potential to increase cutting precision in otologic surgery.

Speech perception in elderly patients following cochlear implantation

CONCLUSIONS

Elderly patients benefit from cochlear implantation in terms of speech perception and quality of life. Age alone should be no contraindication for implantation.

OBJECTIVE

There have been concerns whether elderly patients may perform poorly after cochlear implantation due to degenerative processes in the central and peripheral auditory systems. The purpose of this study was to analyze the benefits of cochlear implantation in elderly patients in comparison to younger recipients.

MATERIAL AND METHODS

We examined 26 postlingually deafened adults aged > 65 years who received a cochlear implant at our center regarding preoperative findings, comorbidities, postoperative complications and quality of life. Speech perception was assessed by means of multi- and monosyllabic word recognition and compared to the results obtained by younger patients.

RESULTS

The surgical procedure was well tolerated by all patients without notable perioperative complications. In terms of speech perception, no significant differences between the elderly patients and younger recipients were noted. All patients found that cochlear implantation had a positive impact on their quality of life.

[Time-dependent vestibular function loss of semicircular canals and otolith organs in Menière's disease]

INTRODUCTION

Since Dohlmann's investigations the extremely variable interindividual natural course of Menière's disease has been documented. The description of sub-entities of Menière's disease shows, the localisation of dysfunction within the labyrinth is of considerable importance. The selective investigation of crista and macula sensor organs and its time-dependent progression even provides information for the disease's staging.

METHODS

In the retrospective trial presented here, 126 patients suffering from vertigo were tested by the methods described above. 10 of these patients who showed a triad of symptoms including vertigo attacks, unilateral sudden hearing loss and tinnitus were selected for this study. All 10 patients were tested within 48 hours after the last acute vertigo attack by means of caloric irrigation and VEMPs.

RESULTS

The function loss verified in saccular testing could be found in Menière's disease progression at an earlier stage than the utricular function loss. Most patients with a long history of vertigo attacks also suffered from a dysfunction of the semicircular canals.

DISCUSSION

The differential testing of the otolith function is a valid tool for the recognition of early labyrinth dysfunction in Menière's disease and could lead to an earlier onset of specific therapy. It also provides the base for a differentiated staging prior to therapy planning.

Otolithenfunktionstests - Ein differenziertes, qualitätsgesichertes Screeningsystem

INTRODUCTION

More than 30% of all otogenic vestibular disorders are related to isolated macular dysfunction. Videooculographic examination techniques for the otolith-ocular reflex, e. g. by means of eccentric rotation tests, are not widely used in clinical routine as these put a considerable strain on technical and staff resources. Thus, there is a considerable risk of "false negative" classification of vertigo disorders being labelled as "non-otogenic". By means of vestibular-evoked myogenic potentials (VEMPs) and caloric irrigation in prone and supine position, several examination techniques for a side-related investigation of macula-induced vestibulo-ocular reflexes are available. The objective of this study is to compare and evaluate these techniques as screening tests.

METHODS

In 32 patients with vestibular disorders we performed investigations for VEMPs, eccentric rotation tests, as well as caloric irrigation for macular reaction in prone and supine position. In addition, we performed other audiologic and vestibular function tests which were complemented by the clinical course in order to differentiate each case between otogenic and non-otogenic vertigo with or without macular affection.

RESULTS

The technical feasibility as well as patients' acceptance for VEMP testing is better than for eccentric rotation tests. The sensitivity index for VEMPs (89%) as well as for caloric irrigation in prone and supine position for macular examination (71%) is satisfactory. However, the specificity of VEMPs is inferior (53%) to eccentric rotation (100%).

DISCUSSION

Both the examination for VEMPs as well as caloric macular testing in prone and supine position carry features which make them feasible for screening, even though these two procedures test for two different parts of the otolith system. However, to confirm a diagnosis and to set up a therapeutic concept for macular function disorders, eccentric rotation should be added.

Idiopathic sudden sensorineural hearing loss in children

OBJECTIVE

Although idiopathic sudden sensorineural hearing loss (ISSHL) is a frequent disease in adults, less is known about incidence and treatment of ISSHL in children.

METHOD

A retrospective chart analysis was performed to evaluate the frequency of ISSHL in children aged under 18 years between 2000 and 2003, who were treated in our department. Children received prednisolone intravenously at an initial dose of 3mg/kg bodyweight. Prednisolone dose was reduced to half every second day. The medication was given for a maximum of 14 days or finished 2 days after the hearing normalized in pure-tone audiometry. The follow-up was continued between 3 and 14 months.

RESULTS

The complete recovery rate was 57%, and the partial recovery was 36%. Initial hearing loss of 50dB and more was predictive for poor outcome in children (p=0.028). Presence of tinnitus was without relevance for the outcome. The incidence of ISSHL in the local area of about 250,000 inhabitants was 1/10,000 in children.

CONCLUSION

ISSHL seems to be a less frequent disease in children than in adults. Severe initial hearing loss is coupled with poor outcome. Under treatment with prednisolone hearing improvement was found in 13 of 14 patients.

Subclassification of vestibular disorders by means of statistical analysis in caloric labyrinth testing

OBJECTIVE

In the past, various attempts were made to perform a quantitative analysis of nystagmographic findings but their diagnostic value was limited. Therefore, the authors present a multivariate analysis of nystagmus findings with the aim of increasing the precision of diagnostic differentiation in cases of vestibular dysfunction.

MATERIAL AND METHODS

A group of 387 patients and 40 healthy volunteers were examined over a 14-month period using electronystagmography after stimulation by bithermal, bilateral irrigation of the labyrinth. Amplitude, slow-phase velocity, frequency and directional preponderance were evaluated.

RESULTS

No defined normal values for caloric nystagmus parameters could be obtained. However, by using the Mann Whitney U-test and logistic regression analysis a differentiation between pathological and healthy findings as well as between central and peripheral vestibular disorders and even between distinct vestibular disease entities is possible. Using these methods, the nystagmus amplitude was found to be the strongest discriminating parameter. Therefore, sole assessment of nystagmographic findings by selective calculation of the nystagmus slow-phase velocity falls short of the potential offered by electronystagmographic registration.

CONCLUSION

For daily clinical routine, counting nystagmus beats leads to the same diagnostic precision as the analysis of slow-phase velocities. In contrast, multivariate analysis of several nystagmus parameters can distinguish between distinct diseases with fairly high precision. This stepwise analysis of nystagmographic data could create the basis for an expert-system tool in the near future.

[Electro-mechanic steering device for head-lamp mounted miniature video cameras]

BACKGROUND

Endoscopic or microscopic video recordings set a widely established standard for medico-legal documentation of operative procedures. In addition, they are an essential part of undergraduate as well as postgraduate medical education. Macroscopic operations in the head and neck can be recorded by miniaturised video cameras attached to the surgeon's head lamp.

METHODS

The authors present an electro-mechanic steering device which has been designed to overcome the parallax error created with a head-mounted video camera, especially as the distance of the camera to the operative field varies.

RESULTS

The device can be operated by the theatre staff, while the sterility of the operative field is maintained and the surgeon's physical working range remains unrestricted. As the video image is reliably centred to the operative field throughout the procedure, a better orientation and understanding for spectators who are unfamiliar with the surgical steps is obtained.

CONCLUSIONS

While other adverse factors to macroscopic head-mounted video recordings, such as involuntary head movements of the surgeon, remain unchanged, the device adds to a higher quality of video documentation as it relieves the surgeon from adjusting the image field to the regions of interest. Additional benefit could be derived from an auto-focus feature or from image stabilising devices.

[Clinical experience with power-regulated contact laser surgery for the paranasal sinuses and the anterior skull base]

BACKGROUND

While laser surgical methods in Otorhinolaryngology have become widely established, their use in revision surgery for chronic-polypous sinusitis has been regarded as hazardous due to the vicinity of the anterior skull base and the orbit. However, new experience with laser-tissue interaction in contact irradiation together with effective power feedback control mechanisms require a re-evaluation of laser revision surgery in this field.

PATIENTS AND METHODS

After 742 primary, endonasal-microscopic sinus surgery procedures, 86 patients had 128 Nd:YAG-laser sessions performed within an interval of 1 - 24 months after primary surgery for recurrent polyposis, which had been irresponsive to medication. The maximum power delivered was 10 to 20 W.

RESULTS

Recurrent polyposis appeared mostly in the maxillo-ethmoid angle, followed by the maxillary sinus roof and the maxillary sinus bottom. In 63 of 86 patients, no further polyposis was seen after laser surgery. If more than one laser session had to be performed, recurrent polyposis appeared in a different region in most cases. Those areas lasered first showed a reduced tendency to recurrence. There was moderate bleeding during laser surgery in 6 cases with reduced visibility, but no other serious complications were recorded.

CONCLUSIONS

Laser surgery for chronic-polypous sinusitis is an alternative to conventional revision surgery, if medical treatment fails and recurrent polyposis is confined to certain regions. Feedback-controlled contact laser power delivery adds further therapeutic safety when applied next to the anterior skull base and the orbit.

Long-term follow-up after laser-induced endotracheal fire

The objective of this presentation is to outline long-term complications and their management in contrast to acute measures after endotracheal laser-induced fire. This case focuses on a 56-year-old patient in whom an endotracheal fire occurred during CO2 laser surgery. Despite local swelling and evidence of acute lung injury, the patient was extubated the following day under single-shot cortisone and inhalation of dispersed adrenaline under assisted spontaneous breathing. Wound healing was assessed by regular flexible bronchoscopy and spirometry. Fourteen weeks after uneventful recovery, the patient presented with acute inspiratory stridor, related to a tracheal stenosis 2.5 cm distal to the glottic level. After tracheal end-to-end anastomosis, further follow-up was uneventful. Early extubation under ITU conditions avoided the need for tracheostomy and its sequelae. However, tracheal stenosis did not become apparent before week 14. While in acute management of laser-induced endotracheal fire a conservative approach was established successfully, the risk of further long-term complications implies the need for a prolonged follow-up regime even in cases of less extensive burns.

[Low-grade malignant peripheral nerve sheath tumor of the neck soft tissues]

BACKGROUND

Malignant Peripheral Nerve Sheath Tumours (MPNST) either grow sporadically, after radiation or chemotherapy respectively. In many cases they are associated with Neurofibromatosis I. Because of the multiform histologic picture they are often difficult to differentiate from other soft tissue tumours.

PATIENT

We present the case of a sporadic MPNST which developed from the vagus nerve of a 39-year-old patient following radiation of the neck 7 years before. After complete excision there has been no recurrence up to now.

RESULTS AND CONCLUSIONS

Sporadic MPNST of the head and neck are comparatively rare. With regard to the strong association with Neurofibromatosis I and the difficult differential diagnosis to other soft tissue tumours the emphasis should be put on excluding further manifestations of Neurofibromatosis I and of secondary tumours.