Biomedical subjects

W Steinbrich

Publications and source records attributed to W Steinbrich.

130 records · Page 8Linked to original sources

PubMedDate not supplied

A new rotational thrombectomy catheter: system design and first clinical experiences.

PURPOSE: To describe a new catheter for the percutaneous mechanical removal of fresh and organized thrombi, and to assess its efficacy and safety in vitro and in vivo. METHODS: The catheter consists of a coated stainless steel spiral that rotates at 40,000 rpm over a guidewire inside the whole length of an 8 Fr, single-lumen, polyurethane catheter, driving a dual-blade cutting crown. Abraded occlusion material is sucked into the catheter head through distal side holes and transported by the spiral into a reservoir at the proximal end. The efficacy of the device was tested in arterial models and fresh bovine carotid arteries (n = 72). In a clinical pilot study 10 patients (8 women, 2 men; mean age 70.6 +/- 10.1 years) with occlusions of the superficial femoral artery (2-12 cm, mean 5.8 cm), not older than 4 weeks, underwent thrombectomy with the new catheter. RESULTS: In arterial models and bovine cadaver arteries the catheter completely removed fresh thrombi. Occlusion material of higher consistency was cut into particles of 100-500 micron and transported outside. Thrombectomy was successful and vessel patency restored in all 10 patients. The ankle/brachial pressure index significantly (p < 0.0005) increased from 0.41 +/- 0. 18 before intervention to 0.88 +/- 0.15 after 48 hr and to 0.84 +/- 0.20 after 3 months. Two reocclusions occurred within 14 days after the intervention. CONCLUSION: Thrombectomy with the new device appears to be feasible and safe in patients with acute and subacute occlusions of the femoropopliteal artery.

Aged↗

PubMedDate not supplied

Anterior neopharyngeal pseudodiverticulum. A possible cause of dysphagia in laryngectomized patients.

Anterior neopharyngeal pseudodiverticula are out-pouchings of the neopharyngeal lumen in laryngectomized patients which can cause postoperative dysphagia. In this study 20 laryngectomized patients were examined endoscopically and with barium swallow to determine the frequency of pseudodiverticulum formation, the correlation with clinical symptoms, and to evaluate the best modality for diagnosis. In 12 patients an anterior neopharyngeal pseudodiverticulum was present. Of these patients eight complained of dysphagia. The barium swallow showed more clearly the pseudodiverticula than laryngoscopy and gave additional information on functional implications. All symptomatic patients were successfully operated on with endoscopic laser therapy.

Adult↗

PubMedDate not supplied

PET, CT, and MR imaging in cerebrovascular disease.

Forty-five patients with cerebrovascular disease (single and multiple infarcts, intracerebral hemorrhages) were examined with X-ray CT, magnetic resonance (MR) imaging, and positron emission tomography (PET). In six patients with acute infarcts repeat measurements with all techniques were performed after 2 weeks. Magnetic resonance and PET were more sensitive in the detection of ischemic lesions than X-ray CT. With PET, functional disturbances could be demonstrated even in two cases where CT and MR were normal, while the latter techniques were superior in exactly localizing a lesion. Changes in lesion appearance with time were observed with all techniques, and the pathophysiologically important phenomena of hyperperfusion or hypermetabolism were documented in four infarcts with PET.

Brain↗

PubMedDate not supplied

Combined 1H-MR imaging and localized 31P-spectroscopy of intracranial tumors in 43 patients.

Combined imaging and volume-selective spectroscopy of normal human brain tissue and tumors located anywhere in the brain could be obtained routinely in a clinical setting. Image-guided localized phosphorus MR spectra of healthy brain tissue have been reproducible, but further examinations seem necessary to determine individual physiologic variations. Compared with healthy brain tissue, spectra from meningiomas demonstrated the most obvious differences: the phosphocreatine peak decreased below the level of adenosine triphosphate, and the phosphodiester signal was reduced, whereas the phosphomonoester peak increased in some cases. Malignant gliomas showed less distinct changes: in particular, the phosphodiester peak was reduced and, in several cases, seemed to split. Often the phosphocreatine signal was diminished. In tumors with cystic components a poor signal-to-noise ratio was found. Four nonmalignant astrocytomas could not be differentiated from normal brain tissue spectroscopically. It has to be proved by an increased number of cases and quantification whether the observed spectral patterns can be correlated to histology. In three patients, follow-up studies during and after radiotherapy were performed. Metabolic changes were observed in one patient in a time frame in which imaging methods did not detect any change. Phosphorous spectroscopy has the potential to emerge as a useful tool in this field.

Adult↗