PubMed Health⌕ Search

Biomedical subjects

W B Winkler

Publications and source records attributed to W B Winkler.

17 recordsLinked to original sources
PubMed1999

[Vena cava filter for prevention of pulmonary embolism].

Vena caval filters in the prevention of pulmonary embolism All currently available caval filters can be implanted percutaneously in local anaesthesia. In the USA the FDA has approved the stainless steel Greenfield filter, the Titanium Greenfield filter, the Bird's Nest filter, the LGM or VenaTech filter and the Simon Nitinol filter. Some other caval filters are commercially available in Europe, but there exist only few clinical trials about them. The Greenfield filter is implanted since the early seventies and the greatest amount of data has been published about it. Standard indications for filter placement are recurrent pulmonary embolism despite adequate anticoagulation, in patients after pulmonary embolectomy, when there is a contraindication to anticoagulation (e.g. fresh surgical wound, active gastrointestinal bleeding, recent haemorrhagic stroke, major trauma,...) and when serious complications occur after thrombolysis or anticoagulation. In patients who suffer from severe cardiopulmonary disease both a caval filter and anticoagulation may be required. Follow-up investigations include plain abdominal radiography and duplex ultrasound, in special cases computed tomography, cavography, magnetic resonance imaging in newer filter types, and intravascular ultrasound. Complications include recurrent pulmonary embolism, caval obstruction, migration, fracture and perforation of filter struts. As clinically relevant complications are rare, in diligently selected cases the patient will benefit from implantation of a caval filter.

Device Approval↗
PubMed1997

Transcranial Doppler for early identification of potential organ transplant donors.

BACKGROUND: Encouraging results in transplant medicine create a growing demand for organ transplant donors. Transcranial Doppler (TCD) has been used by several investigators to assess arrest of the cerebral circulation in brain dead patients. We report on TCD as a monitoring tool for early identification of potential organ transplant donors. DESIGN: A prospective clinical study. SETTING: Intensive care unit (ICU) of a 900-bed community hospital (primary and tertiary care center) in Vienna, Austria. SUBJECTS AND METHODS: All patients with acute intracranial lesions admitted to our intensive care unit underwent TCD examination at least once daily. In patients with Glasgow Coma Scores < 7, TCD waveforms with high resistance profiles unchanged by therapeutic attempts to lower intracranial pressure indicated the need for repeated TCD up to four times a day. TCD waveform abnormality consisting of absent or reversed diastolic flow or small early systolic spikes in at least two intracranial arteries was considered to constitute intracranial circulatory arrest. Brain death was confirmed by clinical criteria, an isoelectric electroencephalography (EEG) or non filling of the intracerebral arteries on arteriography. RESULTS: From January 1994 to July 1996 we identified 11 comatose patients as potential organ transplant donors with typical TCD findings indicating intracranial circulatory arrest. Diagnosis was subarachnoid hemorrhage in 7 and intracerebral hemorrhage in 4 patients. Brain death diagnosis according to the criteria of Austrian law was initiated immediately after the TCD findings suggested intracranial circulatory arrest. Confirmation of brain death was obtained by clinical criteria and either EEG (6 patients) or cerebral angiography (5 patients). CONCLUSION: TCD examinations on a daily routine basis offer a noninvasive monitoring method for early assessment of intracranial circulatory arrest. TCD enables quick identification and further diagnosis of candidates for organ transplant donation.

Adult↗
PubMed1996

Sex-related differences in acetazolamide-induced cerebral vasomotor reactivity.

BACKGROUND AND PURPOSE: Cerebral vasomotor reactivity can easily be assessed reliably by measuring vasodilatory response to acetazolamide by transcranial Doppler sonography. The aim of this study was to confirm the hypothesis that female sex is associated with an increased cerebrovascular flow reserve. METHODS: Blood flow velocity of the middle cerebral artery was measured by transcranial Doppler sonography in 36 healthy sex- and age-matched subjects. After the initial blood flow velocities were recorded, the subjects received 14.3 mg/kg body wt acetazolamide, ie, 1 g/70 kg, intravenously. The measurements were repeatedly performed at 5-minute intervals starting 10 minutes after injection and lasting for 30 minutes. The highest measured flow velocities were used for further analysis. RESULTS: In both groups mean blood flow velocity increased significantly after acetazolamide (women, from 60.2 +/- 12.5 to 89.9 +/- 14.4 cm/s, P < .006; men, from 54.5 +/- 18.8 to 75.7 +/- 24.5 cm/s, P < .02). The difference in mean blood flow velocity after acetazolamide between groups of women and men was statistically significant (P < .02). CONCLUSIONS: Female subjects show an increased vasodilatory response to the acetazolamide test compared with men.

Acceleration↗
PubMed1995

False diagnosis of myocardial infarction due to an extreme left sided cardiac rotation in two patients.

We present two patients with an extremely rare condition: abnormal cardiac levoposition. Alterations in the ECG caused by this congenital abnormality and additional chest symptoms led to the false diagnosis of previous myocardial infarction. Chest X-ray and echocardiography suggested cardiac malformation. Correct diagnosis of cardiac levoposition was established by magnetic resonance imaging.

Aged↗
PubMed1994

[Syringomyelia as a rare cause of respiratory insufficiency requiring ventilation].

For 17 years a now 45-year-old man had suffered from progressively more severe flaccid paresis of the arms and thoracic muscles, spastic paralysis of the legs and kyphoscoliosis. Artificial ventilation was required when he contracted pneumonia. Although it was being treated with antibiotics, frequent bronchoalveolar lavage had to be done because of repeated atelectases. After 6 weeks clonuses developed in the legs, predominantly on the right, stretch synergisms and opisthotonos. The pupils were small with sluggish reaction to light, and there was a positive "doll's head" phenomenon. The level of consciousness alternated between somnolence and sleepiness. Magnetic resonance imaging demonstrated cavities in cervical and thoracic spinal cord, supporting the diagnosis of an abnormal cerebrospinal circulation due to gliosis in syringomyelia. To secure cerebrospinal fluid drainage, the cerebellar tonsils were resected, together with a duraplasty and partial resection of the atlas. Following this he became fully conscious and the spastic state improved. During the following 8 weeks it became possible gradually to wean him from the artificial ventilation and achieve satisfactory mobilization so that he could be discharged to domiciliary care.

Combined Modality Therapy↗
PubMed1994

Treatment of exudative fibrinous pericarditis with intrapericardial urokinase.

Three male patients with purulent pericarditis, in whom complete drainage could not be obtained by pericardiocentesis, were treated with transcatheter intrapericardial urokinase to prevent the development of chronic constrictive pericarditis. As shown by echocardiography, the intrapericardial fibrin layers disappeared in two cases and were reduced by more than half in the third. Effects on systemic coagulation indices and complications related to intrapericardial lysis were not observed.

Adult↗
PubMed1994

Bedside percutaneous dilational tracheostomy with endoscopic guidance: experience with 71 ICU patients.

OBJECTIVE: To assess the value of endoscopic guidance in bedside percutaneous dilational tracheostomy. DESIGN: The medical critical care unit of a large community hospital. SETTING: 71 consecutive adult patients who required prolonged mechanical ventilation. INTERVENTIONS: 72 elective percutaneous dilational tracheostomies using the Ciaglia technique were performed under view of a flexible fiberoptic bronchoscope. MEASUREMENTS AND RESULTS: Patients were examined during tracheostomy and on days 2 and 7 after the procedure, at discharge and after half a year if they were still alive. A correct median puncture was observed by endoscopic control in 59 interventions. An initial paramedian puncture was detected in 13/72 (18%) procedures and was corrected by renewed insertion in all cases. No severe complications related to percutaneous dilational tracheostomy were noticed. Minor complications occurred in 4/71 (5.6%) patients including minor bleeding in 2, inflammatory infiltration in 1 and one superficial lesion of the posterior tracheal mucosa. Long-term follow-up revealed stomal granulation in 3 patients including one at the tracheal site. At the end of the observation period the tracheostomy still was in use in 14/71 (20%) patients and 12/71 (17%) patients were decannulated. Due to their severe underlying diseases 45/71 (63%) patients had died. To facilitate weaning from the tracheostomy a minitracheostomy tube was used in 3 patients. CONCLUSION: Percutaneous dilational tracheostomy is a simple bedside procedure associated with a low complication rate. We recommend the use of endoscopic guidance to increase the safety of tracheal puncture and dilation procedure.

Adult↗
PubMed1994

Initial experience with intravascular ultrasound imaging during carotid endarterectomy.

BACKGROUND AND PURPOSE: To assess the feasibility of intravascular ultrasound imaging during carotid endarterectomy. METHODS: Intravascular ultrasound imaging was performed during carotid endarterectomy in eight patients using an over-the-wire catheter system with a 30-MHz ultrasound probe. In vitro studies were carried out before the intraoperative application, paying special attention to visualization of the wall layers of normal carotid arteries, structures of more or less diseased vessels, and surgically placed materials such as patch, suture material, and fibrin glue. Although intravascular ultrasound failed to distinguish between intima and media in areas of normal intima, fibrotic and calcified plaques were detected clearly. Dacron patch as well as sutures were identified as highly reflective structures. RESULTS: In seven of the eight patients studied, intravascular ultrasound yielded cross-sectional images of good quality allowing identification of the vessel layers and the structures at the endarterectomy site. In all patients the three layers of the vessel wall were clearly differentiated and the transition zone between the site of endarterectomy and the genuine vessel appeared smooth without intimal flaps or residual arteriosclerotic plaques. In one patient severe eccentric thickening of the media was detected in the distal internal carotid artery. Neither damage of the vessel layers by the shunt nor thrombus formation in the operating area and the internal carotid artery were detected. CONCLUSIONS: Intravascular ultrasound lends itself as a potentially valuable method of quality control during carotid endarterectomy. The method seems to enable an accurate evaluation of the endarterectomy site and the search for residual plaques.

Adult↗
PubMed1994

Embolic stroke by compression maneuver during transcranial Doppler sonography.

BACKGROUND AND PURPOSE: Embolic complications during ultrasound examinations are a rare cause of neurological deficits. The present case documents the occurrence of embolism by a nonobstructive compression maneuver during transcranial Doppler examination, resulting in a minor stroke. CASE DESCRIPTION: A 63-year-old man suffered from recurrent transient ischemic attacks. Duplex sonography showed a small echogenic plaque at the right carotid bifurcation. During transcranial Doppler studies with a reverberating compression maneuver of the right common carotid artery low in the neck, multiple emboli signals were detected, and the patient developed a left-sided hemiparesis with slurred speech. Funduscopy revealed cholesterol emboli in the inferior temporal arteriole of the right eye. These findings suggested embolization as the cause of the stroke. CONCLUSIONS: Compression maneuvers should not be performed in patients with recent neurological symptoms, even in the case of only small lesions in the extracranial carotid territory.

Carotid Artery Diseases↗
PubMed1993

The prevalence of deep venous thrombosis in patients with suspected paradoxical embolism.

OBJECTIVE: To determine the prevalence of venous thrombosis in patients with suspected paradoxical embolism. DESIGN: Observational study. PATIENTS: Two hundred sixty-four patients with clinically suspected embolic events underwent contrast transesophageal echocardiographic evaluation. Forty-nine patients (24 women, 25 men) had a patent foramen ovale. Forty-one patients had acute stroke, and 8 had acute limb ischemia. SETTING: Echocardiography laboratory of a community hospital. MEASUREMENTS: The presence of a patent foramen ovale was assessed by transesophageal contrast echocardiography. Forty-two patients had venographic evaluation of the lower-extremity venous system. RESULTS: Venous thrombosis was clinically suspected in 6 patients and documented in 24 of the 42 patients with patent foramen ovale who underwent venographic study (57%; 95% Cl, 41% to 72%). Venous thrombosis was confined to calf or popliteal veins in 15 cases. Fifteen of 17 patients who had venographic evaluation within 7 days of the index event had thrombosis compared with 9 of 25 patients who had later evaluations (P = 0.001). More patients with venous thrombosis than without venous thrombosis had a history of previous thromboembolism (13 of 24 compared with 1 of 18 [corrected], respectively; P = 0.001). CONCLUSION: When a patent foramen ovale is detected in a patient with embolism, occult leg vein thrombosis is frequently present.

Adult↗
PubMed1993

Duplex sonographic detection of internal jugular venous thrombosis after removal of central venous catheters.

Venous thrombosis is a very common complication of central venous catheters inserted via the jugular or subclavian vein. The aim of this prospective study is to test the suitability of duplex sonography in detecting thrombi in the internal jugular vein after catheter removal and to analyze the number and extent of such thrombus formations. The study group comprised 64 consecutive patients with an average age of 59 +/- 16 years admitted to an internal intensive care unit. In 54 cases the catheters were removed under sonographic control. In 10 cases duplex sonography was carried out within 24 h after removal of the catheters. The data of 63 patients were evaluated. In 40 patients (63.5%), thrombi of varying extent were present in the jugular vein. No significant correlations were found between thrombus formation and the basic disease, duration of cannulation, the type of catheters used, and the mode of heparinization (therapeutic vs. low-dose). Local inflammation signs and local hematoma showed a significantly higher incidence (p < 0.01) in patients with thrombus formation. Duplex sonography lends itself as a valuable diagnostic tool in the diagnosis of thrombus formation in the internal jugular vein after removal of central venous catheters. Sonographic examinations should be carried out in all long-stay patients at an intensive care unit, in whom central venous catheters are inserted repeatedly via the internal jugular vein.

Adult↗
PubMed1992

[Strut fractures in the long-term follow-up of Günther cava filters--the results after 64 filter implantations].

Follow-up of patients with inferior vena cava filters was performed every 3 months with clinical controls, plain radiographs and duplex sonography. Whereas the clinical results were excellent (no recurrence of pulmonary embolism), radiological controls showed broken anchoring legs in 14 cases and a broken filter basket in one patient. In two cases, the broken anchoring prongs had perforated the inferior vena cava wall. All patients with broken filters were clinically asymptomatic. CT showed no morphological changes in these cases. As experience proves, strict follow-up of caval filters for early detection of complications is mandatory even with well-established filter types.

Coumarins↗