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Biomedical subjects

A Berghaus

Publications and source records attributed to A Berghaus.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Glomus tumor of the nose].

Between May 1995 and March 1996 we were able to diagnose and remove glomus tumors of the left nasal cavity from three female patients. Ages of the patients were 9, 36 and 74 years. All patients suffered from a frequent epistaxis and all were extremely sensitive to the slightest nasal touch. One patient reported breathing difficulties due to nasal congestion. Examination revealed a tumor that filled the entire nasal cavity. The method of choice in treatment of these tumors is surgical removal. Hemangiopericytoma, non-chromaffin paraganglioma, hidradenoma, cavernous hemangioma and nevus cell nevi have to be excluded by histology and immunohistochemical techniques. From a clinical perspective the bleeding septal polyp (granuloma telangiectaticum sive pyogenicum sive pediculatum) has to be considered because it often comes from Kieselbachi's plexus, has a mushroom-like appearance and bleeds slightly.

Adult↗
PubMed1999

[Endonasal, microsurgical approach to the retrobulbar region exemplified by intraconal hemangioma].

The posterior orbit contain's a number of important and vulnerable structures, including the optic nerve, the opthalmic artery and vein, the ocular muscles and their motor nerves. Because of their close relation to the ocular bult, surgical access to this region is very difficult. Transfrontal, transfrontal-ethmoidal and transmaxillary procedures have the disadvantage of possible injury to a number of non-tumor affected structures. The endonasal microsurgical transethmoid access is described here along with a case report of a 2 x 1 cm intraconal hemangioma. Ethmoidectomy was performed after septal mobilization. The optic nerve was identified in the wall of the sphenoid sinus. The lamina papyracea was resected between the sphenoid sinus wall, skull base and ethmoid. The medial rectus muscle was mobilized after slitting open the periorbita to expose tumor. The hemangioma was then removed in toto under microscopic control. Surgery in the retrobulbar region could be performed gently and under microscopic magnification with this technique. The procedure used has a minor risk in the hands of an experienced nasalsurgeon and opens up new possibilities for the treatment of retroorbital lesions.

Adult↗
PubMed1999

[Risks of upper eyelid gold implantation in peripheral facial paralysis].

Peripheral facial paresis is often accompanied by incomplete closure of the eyelids and may lead to varying degrees of keratopathy. Conservative therapeutic measures are often not sufficient. To achieve better lid closure tarsorraphy has been the primary method of treatment but has certain functional and cosmetic drawbacks for the patient. Alternatively gold weight implants have been used to close the upper lid by the force of gravity and if needed can be combined with further reconstructive facial surgery. From May 1994 to January 1997 29 patients with peripheral facial paralysis were treated with gold weight upper lid implants. Postoperative closure of the lids was sufficient in all cases, and there was a statistically significant decrease in lagophthalmos and improvement in keratopathy. Complications observed included ptosis (n = 5), cosmetically unacceptable bulging of the gold implant (n = 5), extrusion of the implant (n = 1) and the development of a low-grade corneal astigmatism (n = 7). In all cases of astigmatism correction was achieved by the fitting of cylinder glasses. In all, functional results achieved showed that the gold implant was superior to the cosmetically bothersome tarsorraphy.

Adult↗
PubMed1999

[Corneal astigmatism as a special complication after lid-loading in patients with lagophthalmos].

UNLABELLED: Lid-loading with precious metals, described by Illig in 1958, has become increasingly important. because of its good functional and cosmetic results this method is superior to tarsorrhaphy. Furthermore, lid-loading can be combined with additional surgical techniques to achieve more dynamic lid-closure. In a prospective study we examined the results after lid-loading and discuss postoperative changes of the cornea. PATIENTS AND METHODS: Between May 1994 and June 1998, 36 patients with peripheral facial paresis and lagophthalmos were treated with a pretarsally fixed upper-lid implant. We used 99.99% gold for the implants with a weight of 1.5 g on average. RESULTS: In all cases we obtained sufficient postoperative lid closure which resulted in a statistically significant reduction in lagophthalmos and improved keratopathy. Postoperative complications were: pseudoptosis, remaining lagophthalmos, bulge, extrusion, migration and corneal astigmatism. Depending on the implant pressure, an astigmatism of 1-2 D developed in the vertical meridian. In all cases the initial visual acuity was reached by an ordination of cylindrical glasses. CONCLUSIONS: So far, corneal astigmatism as a complication after lid-loading has not received much attention in the literature. In our opinion, the development of astigmatism is caused by implants that are too heavy, an incorrect implant radius and individual cofactors (consistency of lid and cornea). There has been no need for an explantation in any case.

Adult↗
PubMed1999

Influence of CO2 laser application to the guinea-pig cochlea on compound action potentials.

HYPOTHESIS: Experiments in guinea pigs were performed to clarify which, if any, of the CO2 lasers in different modes (continuous wave [cw] and superpulse) can damage the inner ear on application of the laser parameters required for stapedotomy and to determine their application safety. METHODS: The laser effect connected with perforating the basal convolution of the guinea-pig cochlea (cochleostomy) was examined. Acoustic evoked potentials (compound action potentials [CAPs]) yielded information on inner-ear function. RESULTS: In cw mode, even single applications of an approximately four times higher power density (60,000 W/cm2) than necessary for stapedotomy at a pulse duration of 50 msec (energies up to 1 J) and 20-fold applications of effective parameters for a footplate perforation (power density 16,000 W/cm2; energy 0.2 J) did not cause CAP changes. Experimental studies with the CO2 superpulse laser used (peak pulse powers: ca. 300 W) have demonstrated that irreversible CAP alterations already occur in the effective laser range in > 40% of the animals. CONCLUSIONS: Because damage is expected only at much higher energies (> 2 J) than those used clinically, the CO2 laser in cw mode has a high application safety for laser stapedotomy. The application of the CO2 laser in superpulse mode with peak pulse powers of approximately 300 W in stapedotomy appears to be more unreliable and dangerous for the inner ear.

Animals↗
PubMed1998

[Obliterating frontal sinus operation with abdominal fat. Follow-up with imaging methods].

Between 1983 and 1991 ten patients with chronic frontal sinus disease underwent frontal osteoplastic flaps with fat obliteration. In order to judge operative success on a long-term basis all patients were called for postoperative follow-up. They then completed a questionnaire, in which they were asked about postoperative complaints. Additionally, sinuses were examined by computed tomographic (CT) and magnetic resonance imaging (MR). Among the patients evaluated seven had no complaints, and no evidence of disease could be found by medical examination. CT scans showed complete obliteration of the frontal sinuses in all patients. In these patients, two-thirds of the fat had been replaced by connective tissue. MR was used in an attempt to show evidence for suppurative disease in the frontal sinus, but the MR images failed to correlate with symptoms. Additional results could not be obtained when compared to CT. Overall operating success could only be determined by clinical assessment and confirmed the value of the frontal osteoplastic flap with fat obliteration.

Adipose Tissue↗
PubMed1998

[Glands of the human nasal mucosa--electron microscopy and immunohistochemical studies].

BACKGROUND: Ultrastructural characteristics of the nasal glands are presented and possible changes concerning different diseases of the nasal mucosa are investigated. METHODS AND PATIENTS: Specimens from 23 patients suffering from primary ciliary dyskinesia, allergic rhinopathy, and chronic inflammatory hyperplasia were the subject of electron microscopic and immunohistochemical studies. RESULTS: All preparations exclusively showed glands of the serous type. The end segments of the glands were surrounded by contractile myoepithelial cells in a basket-like fashion. Distinct differences in the fine structure of the glands were not observed between the individual groups. The epithelial cells of the efferent ducts consisted of numerous rows forming one layer with pronounced interlockings. These cells in particular showed a high content of mitochondria. This segment of the duct probably has the function of changing the content of water and ions in the nasal secretion. CONCLUSIONS: Our immunofluorescence and electronmicroscopic investigations present the ultrastructure of the nasal glands in detail. We assume an influence of the efferent ducts on the composition of the nasal secretion.

Biopsy↗
PubMed1998

[Effect of the pulsed Er:YSGG and Ho:YAG laser on the organ of Corti of the guinea pig cochlear--a scanning electron microscopy study].

BACKGROUND: Recent experimental studies have demonstrated that, apart from the continuous wave lasers, several pulsed laser systems are also suitable for stapedotomy. The aim of this study was to clarify whether irradiation of the basal convolution of the guinea pig cochlea could cause morphological inner-ear changes using the Er:YSGG and Ho:YAG laser with laser parameters required for stapedotomy. METHODS: After opening the bulla, the basal convolution of the guinea pig cochlea, whose thickness is similar to that of the human stapes footplate, was irradiated with the Er:YSGG and Ho:YAG laser. The laser parameters used were those necessary for an adequate perforation of a human stapes footplate (500-600 microns). The cochleae were removed 90 minutes, 1 day, 2 weeks, or 4 weeks after laser application. The organ of Corti was examined by scanning electron microscopy in all convolutions. RESULTS: Application of Er:YSGG laser parameters effective for stapedotomy (5 pulses, energy: 85 J/pulse, energy density: 36 J/cm2, total energy: 0.425 J) had no adverse effects on the organ of Corti in the guinea pig cochlea. On the other hand, effective Ho:YAG laser parameters (10 pulses, energy: 210 J/pulse, energy density: 90 J/cm2, total energy: 2.1 J) caused damage to the outer hair cells with fusion of stereocilia and formation of giant cilia leading to partial or total cell loss. The inner hair cells and supporting cells were usually normal. CONCLUSION: Our results clearly demonstrate that the Er:YSGG laser has high application safety. It could prove to be a viable alternative to the thermically acting CO2 laser for stapedotomy. The Ho:YAG laser is not well tolerated in animals and has low application safety. Its use in stapedotomy would be unreliable and dangerous for the inner ear.

Animals↗
PubMed1997

Effects of pulsed laser systems on stapes footplate.

BACKGROUND AND OBJECTIVE: The aim of the present study was to investigate the tissue ablation capacity of various pulsed lasers at the stapes footplate. STUDY DESIGN/MATERIALS AND METHODS: Isolated human stapes and bovine compact-bone platelets were used to determine the effective laser parameters and appropriate application technique for achieving a perforation measuring 500-600 microns in diameter. Of interest were also the shape and quality of the perforations, the reproducibility of the perforation effect, and the thermically altered marginal zones occurring at the footplate. Three pulsed laser systems were used: excimer, holmium:YAG (Ho:YAG), and erbium:YSGG (Er:YSGG) lasers. RESULTS: The tissue-ablating effect of pulsed laser systems permits a precise and controlled management of the stapes footplate through low and readily reproducible ablation rates. The extent of thermic side effects at the footplate is lower in comparison to the purely thermically acting cw and superpulse laser systems. The Er:YSGG laser exhibits the highest ablation rate at the stapes and is thus the most effective laser for perforation of the stapes footplate. Though somewhat less effective, the Ho:YAG laser also appears to be suitable for stapedotomy. On the other hand, we do not consider the applied excimer laser (308 nm) to be particularly appropriate at the stapes because of its low ablation rates. CONCLUSION: Thus, the erbium laser could represent an alternative to the argon, KTP 532, and CO2 lasers, already clinically successful in stapes surgery. However, further studies are necessary to examine the transmission of thermic energy into the vestibule and the acoustic stress to the inner ear during laser stapedotomy, to be able to make a definitive statement about the safest and most effective laser system for stapes surgery.

Animals↗
PubMed1996

Effects of continuous-wave laser systems on stapes footplate.

BACKGROUND AND OBJECTIVE: The aim of the present study was to clarify which of the presently available continuous-wave laser systems are best suited for application in stapes surgery. STUDY DESIGN/MATERIALS AND METHODS: Isolated human stapes and bovine compact-bone platelets were used to investigate the connections between the parameters of various laser systems and their effects on bone tissue. The purpose was to optimize the laser parameters required to achieve a perforation measuring 500 microns to 600 microns in diameter. Three different laser systems were applied: the argon and CO2 laser in continuous wave (cw) mode and the CO2 laser in superpulse mode. RESULTS: The suitability of the argon laser for stapedotomy is doubtful in view of the lower absorption coefficient of the stapes for the argon beam and the considerable influence which the degree of pigmentation of the irradiated medium exerts on its effect with the resultant poor reproducibility of the perforation diameter. The beam of the CO2 laser is far better absorbed at the footplate than that of the argon laser. This results in higher effectivity, lower thermic side effects, and better reproducibility of the perforation. The two modes of the CO2 laser do not show any appreciable differences. CONCLUSION: The experimental results presented indicate that the CO2 laser in cw and superpulse mode is the most suitable of the systems now clinically applied in stapes surgery.

Animals↗
PubMed1996

[Intra-orbital space occupying lesion. Differential diagnostic considerations based on a rare case].

The differential diagnosis of an intraorbital tumor is discussed on the basis of a rare case of cyst formation that presented clinically in the lacrimal duct. Rapid progression of exophthalmos and visual loss required an immediate surgical intervention. Using a medial orbitotomy, a cystic tumor was extirpated that had no connection to the paranasal sinuses. Postoperatively, the visual defect and exophthalmos resolved completely. This case demonstrates the problems of differential diagnosis within the orbit that require close interdisciplinary cooperation. The final diagnosis can often be made only after surgical exploration and histopathology of tissue specimens.

Aged↗
PubMed1995

Experimental studies on the suitability of the erbium laser for stapedotomy in an animal model.

Animal experiments in mature guinea pigs were devised to determine whether and to what extent inner ear damage can be caused by in vivo use of the erbium laser for stapedotomy. The present study examined the laser effect in connection with perforation of the basal convolution of the cochlea and subsequent application in the opened cochlea. Acoustic evoked potentials as compound action potentials (CAP) were recorded for changes in inner ear function. Findings demonstrated that five applications of the erbium:YSGG (yttrium-scandium-gallium-garnet) laser (energy, 85 mJ/pulse; energy density, 36 J/cm2) were needed to create a footplate perforation of 500-600 microns and did not lead to CAP alteration in any animal (n = 20). An increase of the repetition rate from 1 to 5 Hz likewise caused no CAP alteration (n = 17). Application of high total energies in the open cochlea (n = 5) to determine the safety of the laser system for stapedotomy revealed that a 10-fold increase in the total energy required for adequate perforation led to irreversible CAP alterations and no CAP could be recorded at a 15-fold increase in total energy. In contrast, a 5-fold maximum increase in total energy caused no CAP alterations. These results demonstrate the safety of the Er:YSGG laser comparable to that of the CO2 laser for stapedotomy, supporting its utility as an alternative method for surgery.

Acoustic Stimulation↗
PubMed1995

[Animal experiment studies on CO2 laser stapedotomy].

Experiments were performed in guinea pigs to clarify which, if any, of the CO2 lasers used can damage the inner ear on application of the laser parameters required for stapedotomy. A further aim was to determine their application safety. The basal convolution of the guinea-pig cochlea was chosen as the application site, since its thickness is similar to that of the human stapes base. We examined the laser effect in connection with perforation of the basal convolution and subsequent application in the open cochlea. Acoustic evoked potentials (compound action potentials [CAP]) yielded information on inner-ear function. Animals without laser treatment were used as controls. Perforation of the basal convolution and laser applications in the open cochlea with the same parameters did not lead to a measurable CAP alteration with the CO2 cw laser (power: 8 W, pulse duration: 50 ms, power density: 3200 W/cm2). An increase of the laser power to 15 W (power density: 6000 W/cm2) and of the pulse duration to 200 and 500 ms (energy: 3 J and 7.5 J) caused partly irreversible CAP alterations; finally, no potential could be recorded any more at a maximal laser power and pulse duration (15 W and 500 ms). Examination of high power densities (40,000 and 60,000 W/cm2) through reduction of the laser beam diameter to 180 microns yielded comparable results.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

[Subjective and objective evaluation of the outcome of rhinoplasty. A retrospective study].

Between 1983 and 1988, 206 patients underwent a septorhinoplasty in the ENT Department of the University Hospital Benjamin Franklin in Berlin. The results of the operation were analysed by an "objective" evaluation form including measurements of cephalometric angles and a "subjective" questionnaire reflecting the patient's view. Ninety-nine patients responded to our questionnaire. About one third of our patients were foreigners (mostly Turks). Seventy-five percent of the results were good in objective as well as subjective terms. Comparison of results between the two sexes did not show a significant difference. A relevant discrepancy between the objective and the subjective results was seen in the foreign patients. The low average age and therefore unrealistically high expectations are a possible explanation for this phenomenon. Patients with small preoperative deformities also turned out to be less satisfied with the outcome even though the objective result was better. While obtaining the objective results, we also realized that the nasofrontal angle seems to be of minor importance for the facial profile. The nasofacial and the nasolabial angle actually seem to be more important for the rhinoplasty and reflect the aesthetic correction of the nose better than the nasofrontal angle. It was much more often possible to correct the nasofacial and the nasolabial angle, while the nasofrontal angle remained uncorrected in many cases. Our retrospective study was able to answer the question whether the aesthetic outcome after rhinoplasty can be rated objectively.

Adult↗
PubMed1995

[Revision of the stapes foot plate with various laser systems. 1: Continuous laser irradiation].

During stapedotomy, the small dimensions and highly sensitive anatomic structures present require the highest degree of precision and safety. The risk of damage to middle and inner ear structures through manipulation with conventional instruments can be reduced by non-contact perforation of the footplate with the laser beam. The present study was devised to clarify which of the presently available laser systems was best suited for use in stapes surgery and thus represent a significant alternative to conventional stapedotomy. Isolated human stapes and bovine compact-bone platelets were used to investigate the connections between the parameters of various laser systems and their effects on bone tissue. The aim was to optimize the laser parameters required to achieve a perforation of 500 microns to 600 microns in diameter. In addition, the thermal effects of laser irradiation were assessed. Three different systems were employed: the argon and CO2 lasers in continuous wave (cw) modes and the CO2 laser in superpulse mode. The lasers investigated offered the advantage of achieving an adequately large perforation with one or a few juxtaposed applications but caused in part extensive thermal side effects at the stapes footplate. To reduce thermal effects, footplate perforation was best performed by several juxtaposed single shots at low power, short pulse duration and small beam diameter. The suitability of the argon laser for stapedotomy was rendered doubtful in view of the lower absorption coefficient of the stapes for the argon laser beam and the considerable influence exerted by the degree of pigmentation of the irradiated tissue sites with a resultant poor reproducibility of the perforation diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗