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Biomedical subjects

D F aWengen

Publications and source records attributed to D F aWengen.

13 recordsLinked to original sources
PubMed2000

[A new self-retaining titanium-gold stapes prosthesis].

Various aspects of stapes surgery have been improved since its introduction in 1958 by Shea. However, fixation of the prosthesis on the long process of the incus remains difficult. Furthermore, the functional result of crimping cannot be predicted. Necrosis of the lenticular process still occurs. A new stapes prosthesis has been developed with the Kurz Co. The use of titanium allowed an innovative design: titanium has a shape memory, and a clip was constructed which uses this memory for fixation on the incus. Two new instruments were also developed to facilitate application of the prosthesis: a prosthesis inserter and a prosthesis crimper. The clip does not strangulate the incus; it is attached only to the superior and inferior surface of the incus, which are the crucial locations for mechanical transmission of the piston-like movements of the ossicular chain. Avoidance of circumferential attachment should reduce the risk of incus necrosis. Once the clip is pushed onto the incus no further crimping is necessary. The piston is of pure gold, as in this company's gold piston which has been in use for many years. In future the prosthesis may be all-titanium.

Gold↗
PubMed1998

[Nasal obstruction].

Explore the source record for details and available documents.

Administration, Intranasal↗
PubMed1998

[Fixation of the temporarily removed posterior wall of the auditory canal with plate osteosynthesis: a new technique].

BACKGROUND: Temporary removal of the posterior external ear canal wall allows excellent exposure of the middle ear and epitympanum without the negative sequelae of a cavity as can occur after canal-wall down procedures. Safe fixation of the bony canal wall, however, has not always been possible with a risk for prolonged healing and bone necrosis. MATERIAL AND METHODS: A new technique permits rigid internal fixation of the posterior canal wall. A titanium miniplate of 10 holes length commonly used for orbital rim surgery is adapted to the cortical surface of the mastoid just posterior to the external ear canal. Six holes for 1.3 mm screws are drilled into the cortical bone: two screws behind the ear canal, two screws on the temporal line, and two on the mastoid tip. All fixation material is then removed and a mastoidectomy is carried out with preservation of the cortical bone for the screws. The external ear canal skin, which has been incised previously near the fibrous annulus with lateral extensions, is mobilized laterally using a newly designed retroflected microraspatory. This creates a vital skin flap that might be essential to avoid bone necrosis. No other skin incisions are needed in the canal. The posterior bony canal wall is cut using an oscillating saw Osseoscalpel, secured by facial nerve monitoring. After middle ear surgery and tympanoplasty have been completed, the canal wall is repositioned and fastened precisely in its place with rigid internal fixation allowing a secure stabilization. RESULTS: This new technique has proven to be safe and reliable on the first five patients. There has been no bone necrosis within an observation period of 18 months. CONCLUSIONS: Rigid internal fixation is an alternative technique to safely readapt the posterior auditory canal wall.

Bone Plates↗
PubMed1998

[A new multivariable sigmoid sinus and dura retractor].

Retraction of the sigmoid sinus and the dura requires a strong instrument. The instruments currently available allow only a limited degree of freedom due to their lack of mobility and versatility. A new sigmoid sinus retractor (Micro-France/Instrumentarium) was designed to facilitate the surgeon's task by offering the following advantages: Three-dimensional mobility of the blade: lateral, rotatory and longitudinal Safe positioning of the retractor by three sets of sharp teeth Fixation of the blade by a single screw Strong retraction without giving way.

Cerebellum↗
PubMed1996

[Improved depth exposure for monocular anterior rhinoscopy with the fiber optic headlight reflector].

The usual position of the light reflector of the fiberoptic headlight over the nose of the physicians allows exposure of only the anterior half of the depth of the nose. This limitation is due to the distance between the visual axis and the axis of light. A simple rotation of the reflector towards the dominant eye of the physician decreases the distance between these axes. This allows exposure of structures within the entire nose and into the nasopharynx. This technique not only facilitates diagnostic assessment but also improves postoperative care after endonasal surgery.

Endoscopes↗
PubMed1995

The airway endoscopy mask: useful device for fibreoptic evaluation and intubation of the paediatric airway.

A mask is presented which allows the administration of 100% oxygen, inhalational anaesthetics, continuous positive airway pressure and intermittent positive pressure ventilation during diagnostic airway endoscopy and difficult intubation with a fibreoptic bronchoscope in paediatric patients. The mask is particularly useful in small or critically ill patients. It may also have its place in teaching situations.

Adolescent↗
PubMed1995

Measurements of the stapes superstructure.

Ten human stapes from fresh temporal bones were measured to obtain relevant distances of the stapes superstructure. The dimensions of the parts of the superstructure are as follows: 1) stapes head 1.14 mm (range, 0.91 to 1.49) in diameter parallel to the axis of the footplate and 0.83 mm (range, 0.65 to 1.08) perpendicular to it; 2) stapes head to shoulders 0.93 mm (range, 0.81 to 1.07), head to foramen 1.26 mm (range, 1.15 to 1.39), and head to lateral surface of stapes footplate 3.19 mm (range, 2.91 to 3.45); 3) neck width parallel to the axis of the footplate 1.18 mm (range, 0.88 to 1.47) and 0.64 mm (range, 0.48 to 0.88) perpendicular to it; 4) anterior crus 0.58 mm wide (range, 0.41 to 0.74) at the shoulder of the arch and 0.51 mm (range, 0.39 to 0.65) closer to the stapes footplate; 5) posterior crus 0.65 mm wide (range, 0.46 to 0.77) at the shoulder of the arch and 0.55 mm (range, 0.38 to 0.75) closer to the stapes footplate; and 6) maximum width of entire superstructure near footplate 2.48 mm (range, 2.06 to 2.98).

Age Factors↗
PubMed1993

[Marijuana and malignant tumors of the upper aerodigestive tract in young patients. On the risk assessment of marijuana].

Advocates of free distribution of marijuana and hashish describe these drugs as harmless. Several experimental in-vitro and in-vivo studies have shown the mutagenic and carcinogenic properties of tetrahydrocannabinol. Several carcinogenic polycyclic aromatic hydrocarbons have been extracted from tar of marijuana pipes. Tetrahydrocannabinol also inhibits the function of the immune system. T-cell lymphocyte counts are lower in chronic marijuana smokers compared to nonsmokers. Phytohaemagglutinin stimulation of lymphocytes as well as phagocytosis by polynucleic granulocytes is decreased. The number of young patients between 20 and 40 years with squamous cell carcinoma of the oral cavity, tongue, and pharynx is rapidly increasing. In the past seven years 34 young patients with squamous cell carcinomas have been treated at this institution. All were chronic marijuana smokers. Due to the often extensive field cancerisation, success of cancer therapy is limited in oral and pharyngeal cancers. Marijuana and hashish cannot be considered harmless. Education of the public about the carcinogenic properties of inhaled substances should include marijuana and hashish.

Adult↗
PubMed1992

The influence of age on the results of stapedectomy.

In a retrospective study, we investigated the results of 384 stapedectomies performed between 1962 and 1989. The purpose was to determine the possible influence of age on the postoperative functional result. The operative technique uniformly consisted of a total stapedectomy, seal of the oval window with perichondrium and replacement of the stapes by a free tragal cartilage graft. The audiometric data at 0.5, 1, 2, and 4 kHz were compared. The patients were divided into five groups based upon chronological age: under 30, 30-40, 41-50, 51-60, over 60 years. Although the preoperative airbone gap (ABG) increased with age at all frequencies, and thus the chance for surgery to improve the ABG, the youngest group showed the best improvement in ABG (P less than 0.05). Using a technique with total removal of the footplate, bone conduction thresholds improved in the frequencies up to 2 kHz. At 4 kHz, they deteriorated in the four oldest groups. The greatest improvement in bone conduction thresholds occurred in the youngest group of patients (P less than 0.05), with a parallel decline in age and postoperative results occurring. The causes of these differences are not yet clear, although spontaneous recovery and greater resistance to operative trauma in the younger age groups might be of influence.

Adult↗
PubMed1992

Screwdriver aspiration. A complication of dental implant placement.

Endosseous implants are part of the prosthodontic rehabilitation of patients who have undergone radical tumor resection in the oral and maxillofacial area. Several complications arising from the use of these implants have been reported. Intraoperative aspiration of a screwdriver as a rare and life-threatening complication is presented. It was followed by a chain of further complications including pneumothorax, late laryngeal obstruction requiring tracheotomy, and pleural effusion requiring drainage. To prevent similar complications, we recommend general anesthesia when placing dental implants in patients who have previously undergone extended radical tumor surgery of the oral cavity.

Aged↗
PubMed1991

Flexible laryngoscopy in neonates and infants: insertion through a median opening in the face mask.

The most common reasons for laryngoscopy in newborns and infants are inspiratory stridor and/or dyspnea. With the help of flexible endoscopes, especially with instruments of diminished diameter, laryngoscopy can be carried out even in premature newborns. We report on a technique of flexible laryngoscopy without the need for restraint and with improved safety. A modified face mask is used for endoscopy. An additional hole is made into the mask with a 4.5 mm drill. It is located in the midline just above the nostrils, about 2.5 cm above the ventilation opening. The flexible endoscope is passed into the nose and pharynx with ease. It does not interfere with the anesthetist's ventilation by the mask. In inhalation anesthesia with halothane, 100% oxygen is supplied. The larynx remains in its physiological position. The head is not retroflexed, and the tongue is not supported by an endoscope as in direct laryngoscopy. No muscle relaxation is used, and muscular activity of the larynx can be observed during spontaneous and assisted ventilation.

Anesthesia, Inhalation↗