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Biomedical subjects

W Wenz

Publications and source records attributed to W Wenz.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Ethics in radiology].

The use of a highly specialized technology means that the radiologist must bear ethical considerations in mind in order to maintain a satisfactory and exemplary relationship between doctor and patient. The indication for modern imaging techniques must be established responsibly and needless follow-up investigations should be avoided. Equipment must be modern and safe, and, by the same token, personnel must undergo further training in optimum use of equipment and evaluation. The risks attendant on the radiological investigation and treatment methods used, and their potential benefits, must be carefully balanced against each other. Ethical problems in the field of radiology are illustrated by concrete examples drawn from everyday practice.

Ethics, Professional↗
PubMed1991

[A technic of magnetic resonance tomographic pelvimetry in obstetrics].

Magnetic resonance imaging (MRL) allows for the first time direct determination of maternal pelvic dimensions without ionising radiation. Phantom measurements and the correlation with traditional pelvimetric measurements in 10 patients after Caesarean section have shown mean differences of +/- 2 mm, with a maximum of 5 mm. The evaluation of pelvic configuration is obtained analogous to the conventional roentgenogram. In addition to conventional or digital x-ray pelvimetry, the soft tissues of the maternal pelvis and the presenting part of the foetus is delineated with high contrast. Positioning in the body coil can be accomplished even late in pregnancy or in impending labour, acceptance by the pregnant women being high. Whereas in a given indication after delivery conventional x-ray pelvimetry continues to be performed, antenatally MRI pelvimetry has now been established in our Departments as the method of choice--based on meanwhile 107 examinations. Present drawbacks are the relatively high cost and the limited availability of MR units.

Evaluation Studies as Topic↗
PubMed1991

CT-guided interventions. Present and future aspects.

Interventional radiology has given us new diagnostic and therapeutic possibilities and is no longer a heroic procedure. The best information for the safest approach, except interventions in the vascular system, is provided by the CT scan. If the indications and conditions are respected and the intervention is done with care, it is possible to reach parts of the body, that were only accessible by surgery until now. In therapeutic interventions this also means, that the radiologist will be involved much more in the care of the patients than before.

Biopsy, Needle↗
PubMed1991

Paratibial fasciotomy.

Paratibial fasciotomy is a new surgical approach to conservatively therapy-resistant venous leg ulcers. Its technique and preliminary results are reported. It is concluded hypothetically that the fasciotomy splitting itself plays the main role for its therapeutical success.

Bandages↗
PubMed1990

Transjugular intrahepatic portacaval stent shunt: preliminary clinical results.

A percutaneous transjugular, intrahepatic portacaval shunt was created by means of a combined jugular and transhepatic approach. In the hepatic tissue track joining the portal and hepatic veins balloon-expandable stents were placed. Two of three patients with life-threatening variceal bleeding and Child C liver cirrhosis benefited from the procedure. One patient in severe hepatorenal failure prior to the procedure died 11 days after the shunt procedure of pulmonary complications. This procedure may be a promising alternative to current therapy in high-risk patients with esophageal bleeding.

Adult↗
PubMed1990

[Insect sting allergy--indication of desensitization and problems in evaluating the therapy].

The hyposensitization in IgE-mediated insect venom reactions is presently the sole causal method of treatment. In more than 90% it is possible to prevent life-threatening anaphylactic reactions after insect stings. Essential, hitherto unresolved or only partly resolved questions include, for instance, objective parameters of success and, in this connection, the necessary duration of therapy. The determination and assessment of the course of specific IgE- and IgG-antibodies with the venom skin titration yield, for the single case, no absolutely safe information regarding the therapeutic effect. An alternative is the provocative sting under clinical conditions, the limitation chiefly results from personal and temporal restrictions.

Antibodies↗
PubMed1990

[Hemodynamic consequences of portal decompression: which is the optimal shunt?].

Increased sinusoidal resistance in cirrhosis results in a decrease of the portal and a compensatory increase of the arterial blood supply to the liver. With increasing vascular resistance and development of extrahepatic collaterals stagnation and even reversion of the portal blood flow may occur. In the latter condition, the arterial blood leaves the liver through two routes: 1) through the sinusoids and the hepatic veins, and 2) through the portal vein. Experimental and clinical studies revealed that the arterio-portal pathway is metabolically inferior to the regular arterio-hepatic-venous pathway. This suggests a decrease in liver function with an increased incidence of hepatic encephalopathy (HE) in patients with reversed portal blood flow. Based on these findings, surgical shunts may be classified according to their effect on the arterial liver perfusion. The end-to-side shunt and the distal splenorenal shunt (DSRS) do not cause diversion of the arterial liver perfusion. In contrast, side-to-side shunts, with the portal vein available as an outflow tract, consistently lead to diversion of the arterial blood supply resulting in reversed portal blood flow. Thus, side-to-side shunts are supposed to have an increased incidence of HE due to decreased liver function. This hypothesis is supported by 7 controlled and randomized studies which reveal comparable results of end-to-side shunts and DSRS but significant disadvantages of side-to-side shunts compared to DSRS.

Hemodynamics↗
PubMed1989

[Experiences with desensitization of early spring pollen allergy using 2 tree pollen extracts].

Forty patients with tree pollen-induced allergy (rhinitis, conjunctivitis or combination from both with asthma) were hyposensitized with an extract from isolated birch pollen or a pollen mixture (hazel-, alder-, oak- and hornbeam pollen). The distribution of the different extracts was random. After 3-year treatment, no statistical differences were found between the two groups, especially regarding clinical effectiveness, duration of symptoms or symptom score. In conclusion, we recommend a hyposensitization with birch pollen extract in tree pollen-induced allergy. If evidence is present of sensitization against other tree pollens, especially hazel or alder, or in cases without therapeutic effect after two years of hyposensitization with birch pollen, an attempt with a tree pollen mixture extract is indicated.

Adult↗
PubMed1989

[The intrahepatic portosystemic shunt. Initial clinical experiences with patients with liver cirrhosis].

A new nonoperative catheter technique to perform an intrahepatic portosystemic shunt by transjugular approach was applied to ten patients with recurrent bleeding from oesophageal and fundal varices. Therefore a balloon-expandable stent was placed between a portal vein and a hepatic vein. Implantation of the stent was successful in seven of the ten patients. Two of these seven patients died 10 and 11 days, respectively, after the procedure, one of them in consequence of respiratory failure, the other due to an uncontrollable bleeding from the site of the percutaneous transhepatic puncture because of a marked clotting disorder. The intrahepatic shunt construction led to a mean reduction of the pressure gradient between portal and hepatic vein of 40%. No recurrence of variceal haemorrhage occurred during the average follow-up time of 5.6 months (3-9 months). One patient developed several episodes of portosystemic encephalopathy. The transjugular intrahepatic portosystemic shunt is effective in the treatment of portal hypertension and might become an alternative to shunt surgery.

Adult↗
PubMed1989

[Treatment of acute iliac artery occlusion by catheter lysis, catheter dilatation and implantation of a new kind of metallic vascular endoprosthesis].

Methods of interventional radiology have achieved a significant importance for the treatment of acute iliac artery occlusion if either local or general clinical controindications preexclude routine surgical means of vessel repair. The newly developed balloon-expandable metal mesh vascular endoprosthesis is shown to accomplish percutaneously a definitive reconstruction of heavily diseased iliac artery vessel segments which very well compares with the hemodynamic and morphologic aspect of surgical treatment such as thrombectomy combined with TEA or bypass surgery. Both, short and long-term results one year after the implantation of two balloon-expandable metallic vascular stents reflect a much higher efficacy in functional treatment of iliac artery related claudication than a routine percutaneous transluminal angioplasty alone. In addition, it is shown that local lysis based on a standard protocol of selective intrathrombus instillation of urokinase helps to clear totally clogged iliac arteries.

Aged↗
PubMed1989

[Form, size and function of the sports heart--differentiation from pathological findings].

Dependent on the nature, intensity and scope of muscular exercise, regular athletic training can result in changes in the size and form of the heart, which can be recorded by radiologic and echocardiographic techniques. Brief anaerobic exercise and purely static forms of training (sprint, strength sports) do not produce substantial increases in the size of the heart, but a rotund heart shape with rounding of the cardiac tip and in some cases a discrete increase in the wall thickness of the ventricular myocardium is frequently observed. Dependent on the scope of the training and the intensity, aerobic, endurance-oriented training (endurance sports) can induce considerable enlargement of all cardiac chambers with a change in the cardiac configuration, which is most nearly comparable to combination mitral vitium. Comparison of physiological hypertrophy of the athletic heart with pathological forms of cardiac hypertrophy (such as cardiomyopathies) is in many cases not unequivocally possible with plain X-ray films, but it is usually successful with echocardiographic examination methods.

Adult↗