Benedikt W. Sedlmaier

Ventilation time of the middle ear in otitis media with effusion (OME) after CO2 laser myringotomy

Objective The aim of this study was to investigate the transtympanic ventilation time, the healing course of the tympanic membrane, the early and late complications, and the recurrence rate of otitis media with effusion (OME) within 6 months after CO2 laser myringotomy with the CO2 laser otoscope Otoscan.

Impact of laser eustachian tuboplasty on middle ear ventilation, hearing, and tinnitus in chronic tube dysfunction.

Objectives: Long-term Eustachian tube dysfunction (ETD) predisposes to various secondary middle ear diseases. Most surgical and prosthetical interventions on the Eustachian tube itself have proven to be ineffective, whereas middle ear surgeries treat the sequelae of ETD without major influence on the underlying tubal pathology. The purpose of our study was to evaluate the outcome of laser Eustachian tuboplasty (LETP) on tubal function and associated otological symptoms in topically anesthetized ETD patients with intact or perforated eardrums. Design: In a prospective clinical investigation, outpatient LETP was carried out in 31 subjects with therapy-refractory chronic ETD. The study population comprised two groups: 16 patients with mesotympanic eardrum perforations diagnosed with noninflammatory chronic otitis media (COM) and 15 patients with intact eardrums including otitis media with effusion, adhesion processes, and dysfunctional pressure equalization. Clinical examination and data acquisition were performed 2 wks before LETP as well as 8 wks and 1 yr postoperatively. On COM patients, LETP was done at 10-wk intervals before the scheduled tympanoplasty. Assessment of clinical effectiveness was based on transnasal videoendoscopy, ear microscopy, tubal function tests (Valsalva maneuver and passive tubal opening), audio- and tympanometric measurements, and visual analog scales. Tansnasal, fiber-guided laser surgery was performed in contact mode using a semiconductor diode laser (&lgr; = 830 nm, 4 W). We hypothesized that regulated laser ablation of hyperplastic mucosa at the epipharyngeal dorsal circumference of the tubal ostium could be effective in improving the associated symptoms such as dysfunctional pressure equalization, aural fullness, conductive hearing loss, and tinnitus. Results: LETP resulted in persistent volume reduction of the posterior tubal circumference in all patients. Objective parameters revealed significant improvement of tubal function tests and middle ear ventilation in 62% of subjects after 8 wks (66% after 1 yr). Significant long-term reduction of conductive hearing loss was achieved in both patient groups. Besides, tinnitus loudness was significantly reduced in COM subjects after tympanoplasty. Visual analog scales showed very low values for intraoperative pain and discomfort and high scores for long-term overall patient satisfaction as well as improvement of the symptoms such as dysfunctional pressure equalization and aural fullness. Subjects with post-LETP Valsalva feasibility marked higher values for satisfaction and symptom improvement than patients without successful Valsalva maneuver. COM subjects scored higher in hearing improvement and satisfaction after LETP and successful tympanoplasty than patients with intact eardrums. Conclusions: Outpatient LETP seems to be a suitable, safe, easily applicable, and well-tolerated treatment option before (revision) tympanoplasties and in all investigated diseases developing from long-lasting pathologic middle ear ventilation. Minimally invasive shaping of the hyperplastic nasopharyngeal Eustachian tube under topical anesthesia seems to be effective in improving tubal function as well as the associated symptoms such as dysfunctional pressure equalization, aural fullness, and conductive hearing loss in otherwise therapy-refractory chronic ETD.

Das NEN®-HNO-Navigationssystem Erste klinische Anwendung

ZusammenfassungHintergrund. Die intraoperative Navigation wird in naher Zukunft eine wichtige Rolle in der Chirurgie der vorderen und seitlichen Schädelbasis spielen. Elektromagnetische Navigationssysteme bieten gegenüber den optischen Systemen Vorteile, wie z. B. eine bedienungsfreundliche Größe der Hardware oder die uneingeschränkte Bewegungsfreiheit des Chirurgen. Patienten und Methode. Das NEN-Navigationssystem (Nicolet Electromagnetic Navigation System) wurde bei 22 Patienten mit einer polypösen Pansinusitis während der mikroskopisch/endoskopischen Nasennebenöhlenoperation eingesetzt. Es handelt sich um den Prototypen eines neuen Systems, bei dem die Positionsbestimmung über die Messung gepulster elektromagnetischer Gleichfelder realisiert wird. Dieses System wurde für die spezielle Anforderung der HNO-Heilkunde/Kopf-Halschirurgie modifiziert. Die präoperative Bildgebung bestand aus einer axialen Computertomographie (CT) mit einer Schichtdicke von 1 mm bei unwesentlich höherer Strahlenbelastung wie bei einem konventionellen koronaren CT der Nasennebenhöhlen. Die Erfahrungen, die während der klinischen Anwendung gesammelt wurden, wurden genutzt, um die Navigationsgenauigkeit zu optimieren. Ergebnisse. Die Anzahl und die Positionen der Marker wurden schrittweise modifiziert und verbessert. Sechs Marker, die das Volumen der Nasennebenhöhlen umschließen (drei frontal, zwei mastoidal und ein medianer Marker im Bereich der Sutura parietooccipitalis), ergaben die höchste Genauigkeit. Der Einfluss ferromagnetischer Instrumente wie v. a. Nasenspekula, die die Navigationsgenauigkeit beeinflussen, wurden durch Titaninstrumente ersetzt. Des Weiteren wurde eine Registrierungsmöglichkeit der intraoperativen Kopfbewegung mit Hilfe einer sensortragenden Zahnschiene entwickelt, die am Oberkiefer fixiert werden kann. Mit diesen Modifikationen war es möglich eine Navigationsgenauigkeit von 1,5 mm im Bereich des Keilbeins bei freier Kopfbewegung des Patienten zu erreichen. Schlussfolgerung. Die präzise computergestützte Navigation wird mittelfristig ein unverzichtbares Hilfsmittel in der Schädelbasischirurgie werden. Das beschriebene elektromagnetische System bietet eine akzeptable Genauigkeit im Bereich der vorderen Schädelbasis. Für den Routineeinsatz wie z.B. in der endonasalen Nasennebenhöhlenchirurgie müssen die Navigationssysteme preisgünstiger werden und einfach zu bedienen sein.AbstractBackground. Intraoperative computer navigation will soon play an important role in procedures performed on the anterior and lateral skull base. Electromagnetic systems compared to optical systems offer some advantages such as small hardware dimension and free unimpaired mobility of the surgeon. Patients and methods. The NEN navigational system (Nicolet Electromagnetic Navigation System) was used in 22 patients who underwent microscopic/endoscopic surgery for polypoid rhinosinusitis. It is the prototype of a new system, which localizes the surgical probe via the measurement of pulsed electromagnetic DC fields. This system was modified for the needs of head and neck surgery. Preoperative imaging data consisted of an axially oriented spiral computed tomography (CT) resulting in a slice thickness of 1 mm with a radiation dose slightly higher than a routine coronary CT scan of the paranasal sinuses. Results. The data acquired during clinical application was used to optimize navigation accuracy. The number and positions of the markers were gradually modified and improved. Six markers including the volume of the paranasal sinus system (three non-coplanar frontal markers, one on each of the mastoid processes and one median marker on parietooccipital junction) offered the best navigation precision. Additionally, all surgical instruments measured as ferromagnetic, i.e., nasal specula, were replaced by titanium instruments. An adapter affixed to the maxilla designed to hold a second sensor used to track the patients head was developed. With these modifications, it was possible to improve navigation accuracy to 1.5 mm in the plane of the sphenoid bone while retaining free head movement of the patient. Conclusion. For routine procedures such as microscopic/endoscopic endonasal sinus surgery, the systems have to be cost effective and easy to operate.

Correlation of olfactory dysfunction of different etiologies in MRI and comparison with subjective and objective olfactometry

BACKGROUND The clinical diagnosis of olfactory dysfunction of different etiologies has been standardized by the German Working Group of Olfactology and Gustology, but there is no agreement about the most suitable imaging modality for diagnosing this disorder. MATERIAL AND METHODS A total of 24 patients (13 women, 11 men; mean age 52 years) with different types of olfactory dysfunction (anosmia, hyposmia) were examined by objective and subjective olfactometry and magnetic resonance imaging (MRI) of the olfactory bulb. RESULTS There was a positive correlation between objective olfactometry and volumetry of the olfactory bulb but no correlation between subjective olfactometry and MRI. CONCLUSION MRI allows an evaluation of the olfactory bulb and appears to be superior to other modalities such as computed tomography (CT). Objective olfactometry remains the gold standard for reliable diagnosis of olfactory dysfunction.

Development of a tympanic membrane model for laser myringotomy

This study investigates guinea-pig and horse tympanic membranes, sheep dura and chicken eggshell membranes in terms of thickness, histology and tissue interaction with the carbon-dioxide and the erbium:YAG laser. Comparison with formalin-fixed human tympanic membranes as reference structure has provided a suitable model for further research in laser myringotomy. The horse tympanic membrane seems to meet our demands regarding the three parameters mentioned above.

Effects of different IR laser systems on the tympanic membrane

Lasers suitable for myringotomy are the erbium:YAG laser (2940 nm) and the carbon-dioxide laser (10600 nm). The study examines the laser-tissue interaction with tympanic membranes of guinea-pigs, horses and formalin-fixed human tympanic membranes and the effects demonstrated by light-microscopy and scanning-electron-microscopy. The minimum energy densities for a perforation with the erbium:YAG laser in guinea-pig ear drums and formalin-fixed human tympanic membranes are 8 J/cm2 and 16 J/cm2 respectively. There are no thermic side effects. With the carbon-dioxide laser thermic side effects only occur with energy transmission via silver halide polycrystalline fiber. The minimum power density for perforation is 400 W/cm2 (pulse duration 50 ms). With the microslad 719 micromanipulator (Sharplan, Israel, Tel Aviv), the minimum power densities for perforation of guinea-pig and horse eardrums and for formalin-fixed human tympanic membranes are 150 W/cm2, 300 W/cm2 and 600 W/cm2 (pulse duration: 50 ms) respectively. The minimum power density to achieve a perforation with the SwiftLaseTM 757 scanner (Sharplan, Israel, Tel Aviv), is 250 W/cm2 in guinea-pig eardrums (pulse duration: 100 ms). A prototype of a hand-held carbon-dioxide laser otoscope is suitable for performing laser myringotomies in formalin-fixed human tympanic membranes.

Experimentelle und klinische Erfahrungen mit dem Er:YAG-Laserotoskop

ZusammenfassungHintergrund und Fragestellung. Laserotoskope eignen sich für eine ambulante, schmerzfreie Behandlung der sekretorischen Otitis media (SOM) in Oberflächenanästhesie. Lasermyringotomieperforationen sollten einen Durchmesser von mindestens 2 mm haben, um das Mittelohr für etwa drei Wochen zu belüften. Patienten/Methodik. In dieser Arbeit wurde überprüft, inwieweit ein Prototyp eines Er:YAG-Laserotoskops (Fa. Baasel Lasertechnik, Starnberg) zur Durchführung von Lasermyringotomien an Patienten geeignet ist. In In-vitro-Experimenten mit formalinfixierten humanen Trommelfellen wurden die Parameter für den klinischen Einsatz eines Er:YAG-Otoskops erarbeitet. Mit fokussiertem Laserstrahl (Strahldurchmesser 500 μm) erzielt man ab einer Energie von 70 mJ (Energiedichte 36 J/cm2) mit einem Laserpuls Perforationen mit einem Durchmesser von 50 μm. Mit einer Energie von 100 mJ erhält man Perforationen mit einem Durchmesser von 150 μm. Die Ablationsrate des fokussierten Laserstrahls, d. h. der Schichtdickenabtrag pro Laserpuls, beträgt bei einer Energie von 70 mJ ca. 100 μm. Dies bedeutet, dass formalinfixiertes humanes Trommelfell mit einer normalen Schichtdicke von 100 μm mit einem Laserpuls zu perforieren ist. Ergebnisse. Zehn Patienten mit sekretorischer Otitis media wurden in Oberflächenanästhesie des Trommelfells (8% Tetracainbaselösung in Isopropylalkohol für 15 min) mit fokussiertem Strahl mit einer Pulsenergie von 100 mJ (Energiedichte 52 J/cm2) behandelt. Ein ausreichender Perforationsdurchmesser von ca. 2 mm konnte mit durchschnittlich 15 nebeneinander liegenden Pulsen angelegt werden, wobei das Vorgehen durch austretendes Sekret und Trommelfellblutungen behindert wurde. Zwischen den Laserapplikationen musste häufig unter otomikroskopischer Kontrolle abgesaugt werden. Die Heilungsverläufe wurden in klinischen Nachuntersuchungen kontrolliert. Die Perforationen mit einem Durchmesser von 2 mm heilten innerhalb von 14 Tagen. Bei den verwendeten Parametern wurde keine Innenohrfunktionsstörung beobachtet. Schlussfolgerungen. Eine effektive, schnelle und praktische Durchführung der Lasermyringotomie ist mit dem Er:YAG-Otoskop z. Z. noch nicht möglich.AbstractBackground and objective. Laserotoscopes are suitable for low-pain outpatient surgery of otitis media with effusion (OME) under topical anesthesia. The myringotomy perforations should have a diameter greater than 2 mm to ventilate the middle ear for approximately 3 weeks. Patients/Methods. In this study, the clinical applicability of a prototype of an Er:YAG laserotoscope (Baasel Lasertechnik, Starnberg, Germany) was tested. Formalin-fixed human tympanic membranes yielded the parameters suitable for clinical application of an Er:YAG laserotoscope in patients. With a focussed laser beam (beam diameter 500 μm), one is able to achieve perforations of 50-μm diameter with one single laser pulse applying pulse energies of 70 mJ (energy density 36 J/cm2). The ablation rate, i.e. , the tissue layer that is ablated per laser pulse, is 100 μm using pulse energies of 70 mJ. This means that formalin-fixed human tympanic membrane can be perforated with one single laser pulse. Results. Ten patients with OME (otitis media with effusion) were treated under topical anesthesia of the tympanic membrane (8% tetracainbase in Isopropanol for 15 min) with focussed laser pulses (beam diameter 500 μm) with energies of 100 mJ (energy density 52 J/cm2). A sufficient perforation diameter of 2 mm could be achieved with an average of 15 juxtaposed laser applications. The enlargement of the perforations was made difficult by extruding middle ear secretions and slight bleeding of the tympanic membrane. Between laser applications, the target tissue had to be cleaned by suctioning using the operation microscope. The healing of the tympanic membrane was verified and compared in postoperative clinical follow-ups. With a perforation diameter of 2 mm, the Er:YAG laser myringotomies healed within 14 days. The used parameters did not generate side effects such as inner ear hearing loss. Conclusions. An effective, easy, and practical performance of laser myringotomy is not currently possible with the Er:YAG laserotoscope.

Transtympanic Middle Ear Ventilation in Otitis Media with Effusion (OME) after Myringotomy with a CO2 Laserotoscope

Summary The aim was to investigate the transtympanic ventilation time, the healing course of the tympanic membrane, the early and late complications and the recurrence rate of otitis media with effusion within six months after CO 2 laser myringotomy with the CO 2 laser otoscope Otoscan™. In this study, myringotomy was performed with the CO 2 laser otoscope Otoscan™ in a patient population comprising 81 children (159 ears) with a history of otitis media with effusion (OME) associated with adenoidal and sometimes tonsillar hyperplasia. The procedure on the tympanic membrane was accordingly combined with an adenoidectomy, a CO 2 laser tonsillotomy or a tonsillectomy and therefore performed under insufflation anesthesia. In all ears, approximately 2 mm circular perforations were created in the lower anterior quadrants with a power of 12–15 W, a pulse duration of 180 ms and a scanned area of 2.2 mm in diameter. None of the children showed postoperative impairment of cochleovestibular function such as sensoneural hearing loss or nystagmus. Otomicroscopic and videoendoscopic monitoring documented the closure time and healing pattern of tympanic membrane perforations. The mean closure time was found to be 16.35 days with a minimum of 8 and a maximum of 34 days. As a rule, an onion-skin-like membrane of keratinized material was seen in the former myringotomy perforations at the time of closure. At the follow-up six months later, the condition of the tympanic membrane of 129ears could be checked by otomicroscopy and videoendoscopy and the hearing ability by audiometry. The CO 2 laser myringotomy sites appeared normal and irritation-free. Two of the tympanic membranes examined (1.6%) showed atrophic scar formation, and one (0.8%) had a perforation with a diameter of 0.3 mm. The perforation was seen closed in a control otoscopy 15 months postoperatively. OME recurred in 26.3% (n = 10) of the ears seen intraoperatively with mucous secretion (n = 38) and in 13.5% (n = 5) of the ears with serous secretion (n = 37) (p The most important principle in treating OME is ventilation of the tympanic cavity. CO 2 laser myringotomy achieves this via a self-healing perforation whose diameter roughly determines the duration of transtympanic ventilation. Laser myringotomy competes with ventilation tube insertion in the treatment of OME. It may be a useful alternative in the surgical management of secretory otitis media.

Endoscopic CO2 Laser Surgery for Zenker's Diverticulum – Application of Various Scanner Systems

Summary Endoscopic hypopharyngeal myotomy in Zenkers diverticulum is an established alternative to conventional surgical diverticulum resection by external access. This study discusses the surgical procedure, postoperative follow-up and results of endoscopic laser myotomy with various scanner systems. Therapeutic course and success of the procedure are assessed on the basis of a retro- and prospective analysis of symptoms reported by the patients and image documentation of the swallowing process. Two different scanner figures (SurgiTouch™ and AcuBlade™ (Lumenis, Tel Aviv, Israel)) were used intraoperatively and the advantages of their clinical application were evaluated.

IR Lasers and Application Systems for Myringotomy

Abstract.The study examines an Er:YAG laser (2940 nm) and different application systems of the CO2 laser (10 600 nm) with regard to their suitability for a one-shot laser myringotomy of an adequate perforation size (∼2 mm). The laser–tissue interaction of the Er:YAG laser and the CO2 laser in fresh tympanic membranes of horses (thickness: 80–100 µm) as well as in formalin-fixed human tympanic membranes (thickness: 100 µm) is studied correlating perforation diameters to the applied power/energy density and the effects demonstrated by light and scanning electron microscopy are analysed. Using the Er:YAG laser with a focused laser beam (spot diameter: 400 µm) or with a maximally defocused laser beam (spot diameter: 1600 µm) perforations of an adequte size (2 mm) can only be achieved with multiple laser pulses. Histological studies disclose only minimal thermic side effects in the adjacent tissue in both specimens. If the CO2 laser radiation is transmitted via a silver halide polycrystalline fibre (diameter: 900 µm) a maximal perforation diameter of 1300 µm is achieved with significant thermic side effects such as coagulation. Using an Acuspot™ 710 micromanipulator (focused beam diameter: 180 µm) combined with a SilkTouch™ scanner a maximal perforation diameters of 1700 µm can be achieved in horse tympanic membrane with one laser pulse. A prototype of a hand-held CO2 laser otoscope in combination with the SilkTouch™ scanner is suitable for performing laser myringotomies with a diameter of 2 mm with a single laser pulse in fresh horse tympanic membrane.