[Successful therapy of post-traumatic aneurysma spurium by ultrasound-guided percutaneous thrombin injection].
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Biomedical subjects
Publications and source records attributed to K Lackner.
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OBJECTIVE: The purpose of the study was to examine the possibilities for reducing radiation exposure in uroradiology using digital flat-panel silicon X-ray detector radiography. We compared the subjectively determined image quality of abdominal radiographs and urograms obtained on a digital flat-panel detector radiography system with those obtained on a computed radiography system. SUBJECTS AND METHODS. Fifty patients who had a clinical indication for urography underwent unenhanced abdominal imaging that was alternately performed using flat-panel silicon X-ray detector radiography or computed radiography. For patients who required a second radiograph with contrast medium, the examination modality was changed to avoid exposing the patients to excess radiation. The images obtained on flat-panel X-ray detector radiography were obtained at half the radiation dose of the images obtained on computed radiography (800 speed vs 400 speed). The resulting 50 pairs of images were interpreted by four independent observers who rated the detectability of structures of bone and the efferent urinary tract relevant to diagnosis and compared the image quality. RESULTS: At half the radiation dose, digital flat-panel X-ray detector radiography provided equivalent image quality of the liver and spleen, lumbar vertebrae 2 and 5, pelvis, and psoas margin on abdominal radiographs. The image quality obtained with digital flat-panel X-ray detector radiography of the kidneys, the hollow cavities of the upper efferent urinary tract, and the urinary bladder was judged to be statistically better than those obtained with computed radiography. CONCLUSION: With half the exposure dose of computed radiography, the flat-panel X-ray detector produced urograms with an image quality equivalent to or better than computed radiography.
OBJECTIVES: In cancer treatment, arterial blood flow reduction by embolization combined with intra-arterial chemotherapy may be advantageous by achieving high and prolonged drug concentrations in the tumor, and lower systemic drug exposure. The pharmacokinetics of intra-arterial mitomycin C (MMC) was investigated in patients with liver metastases undergoing chemoembolization treatment. METHODS: The chemoembolization treatment consisted of the use of polyvinylalcohol microspheres (ITC-Contour, diameter 150-250 micro m, irreversible vessel occlusion, 20 mg MMC, 15 patients) followed by sealing of the supplying artery with Ethibloc. Alternatively, starch microspheres (Spherex, diameter 45 micro m, biologically degradable, 10 ml of suspension containing 60 mg starch/ml, 20 mg MMC in 7 patients, 15 mg/m2 body surface in 3 patients) were used. MMC was infused over 6 min into the artery supplying the tumor. Serum MMC concentrations were determined from peripheral venous blood samples [protein precipitation with acetonitrile, reverse-phase HPLC with ultraviolet detection (C18 column, elution with 0.01 M, pH 6.5 phosphate buffer/methanol, v/v 70:30, 365 nm)]. The pharmacokinetic parameters were computed assuming an open two-compartment model and linear kinetics. RESULTS: The disposition parameters for MMC in patients treated with polyvinylalcohol microspheres were comparable to data from the literature (C(max)=913+/-98 ng/ml, T(max)=7.7+/-0.3 min, V(c)=0.27+/-0.03 l/kg, V(ss)=0.59+/-0.07 l/kg, Cl=757+/-67 ml/min, T(1/2 alpha)=5.8+/-0.8 min, T(1/2 beta)=50.4+/-4.1 min). There was no significant difference in the disposition parameters for MMC between patients treated with polyvinylalcohol microspheres and those treated with starch microspheres ( P>0.05). In particular, there was no significant difference in the standardized AUC between the groups; this implies that the systemic toxicity of MMC is comparable when polyvinylalcohol microspheres and ethibloc (AUC 1472+/-123 microg min/l per 1 mg MMC) or starch microspheres (AUC: 1448+/-172 microg min/l per 1 mg MMC) are used. CONCLUSION: The AUC values found in this study do not indicate a reduction in the systemic toxicity of MMC if applied intra-arterially in combination with embolizing microspheres, when compared to the AUC values in the literature for intra-arterial application without embolization, or intravenous MMC application. The amount of starch microspheres may have been too small to cause marked effects. On the other hand, there is a very wide range of AUC values reported in the literature for different application modes, and the use of such historical controls is not adequate for detecting more subtle advantages of the chemoembolization procedure, which may, however, exist.
Of decisive importance for the outcome of burn victims are the depth and extent of the burn, and the age and general state of health of the patient. At the site of the injury, the most important initial measure is the abundant application of cold water to the undressed victim. Early intubation of the burn victim should not be employed too readily. When the burns cover more than 10% of the body surface there is an acute danger of shock, and rapid fluid replacement must be aggressively pursued; the infused volume is calculated on the basis of the extent of the burn (Parkland formula). To treat pain, the i.v. administration of opiates or ketamine in combination with benzodiazepines has proven value. The onsite management of the burns should be restricted to the application of sterile dressings. Grade 1 and 2a burns may be treated out of hospital by cooling, cold water application, burn ointment dressings. More severe burns require hospitalization and surgical management. Since the severity of burn trauma is often underestimated, rapid hospitalization is to be recommended.
The formation of a gastric tube for esophageal replacement requires partial devascularization of the stomach and induces microcirculatory changes in the anastomotic region of the gastric fundus. The additional influence of celiac trunk stenosis on anastomotic healing has not been investigated. In total, 23 patients with an esophageal carcinoma underwent transthoracic esophagectomy. Reconstruction was performed by a gastric tube (x22) with cervical or thoracic esophagogastrostomy or colon interposition (x1). All patients had a selective mesenterico-celiacography preoperatively via puncture of the right femoral artery. Preoperative cardiovascular and pulmonary risk factors were assessed. Angiographic findings were correlated to postoperative anastomotic leakage of esophagogastrostomy (x22). In seven out of 23 patients (30.4%), a stenosis of the celiac trunk could be demonstrated (x3 stenosis of 50%, x4 stenosis > 80%). Except for one patient with an additional stenosis of the superior mesenteric artery of > 80%, none of the patients with celiac trunk stenosis developed a postoperative anastomotic leakage of the esophagogastrostomy. Coronary artery disease was the only preoperative risk factor to predict a stenosis of the celiac trunk. Isolated stenosis of the celiac trunk does not seem to impair circulation of the gastric tube.
OBJECTIVES: To evaluate the performance and efficacy of endovascular irradiation after percutaneous transluminal angioplasty (PTA) of de-novo femoropopliteal stenoses in a pilot study. METHODS: 6 patients received non-centered endovascular irradiation (12 Gray at surface of the vessel wall) immediately after angioplasty of de-novo femoropopliteal stenosis, 1 patient was given centered endovascular irradiation using 192-iridium (12 Gray at surface of the vessel wall) Centered irradiation was considered for two other patients. Duplex sonographies and interviews were performed the day before and after PTA and after 1, 3, 6, 9, 12, 18, 24 months up to 4 years. Intraarterial angiography was performed in symptomatic patients. RESULTS: Non-centered endovascular irradiation was possible in all patients without problems or complications. Centered irradiation was not possible in two patients with the cross-over approach. One thromboembolic complication occurred during centered irradiation. Both restenosis and new stenosis at the edge of irradiated distance occurred in 1/7 patients. No other side effects were observed during follow-up. CONCLUSIONS: In our pilot study endovascular irradiation after angioplasty of de-novo femoropopliteal stenosis was possible with low rates of complications and restenosis and taking vessel anatomy into account.
PURPOSE: To evaluate the diagnostic value of digital flat-panel radiography in uroradiology the i. v. urograms of patients who had been examined with computed radiography and digital flat-panel radiography were compared regarding image quality. METHODS: 50 patients who underwent clinically indicated i. v. urography were examined with digital flat-panel radiography and computed radiography. In order to avoid unnecessary double exposure to X-rays, patients were examined either by flat-panel or computed radiography before injection of contrast media. Each further clinically indicated exposure after administration of contrast media was done by alternating the other examination technique. The digital images were compared by 4 radiologists regarding image quality for the detection of defined anatomic structures. RESULTS: Digital flat-panel radiography showed an image quality of the liver, spleen and both kidneys that was similar to computed radiography. The urinary tract, lumbar spine, pelvis and psoas muscle were significantly better visible on flat-panel radiography images. CONCLUSIONS: Compared to computed radiography there is no loss of image information by using digital flat-panel radiography in uroradiology. On the contrary, some anatomic structures on abdominal survey images show better image quality. In conclusion, digital flat-panel radiography has the potential to replace computed radiography in uroradiologic examinations.
OBJECTIVE: Endoscopic procedures may represent an alternative to microsurgery or shunt operations in intra- or paraventricular pathologies. However, the operative results mainly depend on the selection of suitable patients. In the present study of 30 patients with occlusive hydrocephalus, the relevance of differentiated magnetic resonance (MR) imaging for evaluation of the pathophysiological and anatomic prerequisites was investigated. PATIENTS AND METHODS: Apart from conventional axial T(2) -weighted turbo spin echo (TSE) sequences (TR/TE 2126/100 ms) and T(1) -weighted spin echo (SE) sequences (TR/TE 450/15 ms) with and without the administration of Gd-DTPA, the MR protocol included sagittal and coronal thin-sliced T(2) -weighted TSE sequences, cardiac-triggered (TR/TE > 2700/120 ms, slice thickness 3.0 mm) or in volume technique (TR/TE 4000/180 ms, slice thickness 1.4 mm). For the visualization of CSF flow, a sagittal and axial phase-contrast-multi-heart-phase (PCMHP) measurement with 16 phases per cardiac cycle and flow sensitivity in the cranio-caudal direction (TR/TE 18/9.5 ms and 14/9.5 ms) was performed. RESULTS: The combination of imaging and flow sequences provided most information about the extent and the etiology of hydrocephalus. An obstruction of CSF pathways could be detected by the absence of flow voids in T(2) -weighted TSE sequences or of flow signals in PCMHP sequences. The size of the foramen of Monro and of the third ventricle could be evaluated in thin-sliced T(2) -weighted TSE sequences, for the foramen of Monro in coronal and sagittal and for the third ventricle in coronal and axial slice direction, respectively. The basal structures of the third ventricle, including its floor, the infundibular recess, the mamillary bodies, and the basilar artery, could be best identified in sagittal thin-sliced T(2) -weighted TSE scans, cardiac-triggered or in volume technique. CONCLUSION: In occlusive hydrocephalus, a differentiated MR protocol with thin-sliced T(2) -weighted TSE sequences and phase-contrast sequences allows a very precise estimation of the pathophysiological and the anatomic prerequisites for endoscopic procedures. Furthermore, MR imaging can be used for the follow-up documentation of ventriculo-cisternostomies, -cytostomies, or openings of other membranes.
OBJECTIVES: To evaluate the effectiveness of ultrasound thrombolysis in vitro in comparison with thrombectomy, and in vivo as a pilot-study for the treatment of thrombotic occlusions of peripheral arteries. METHODS: Under standardized conditions, one-day-old and five-day-old thrombi of whole blood, thrombin-induced thrombi and old organized thrombi of human blood were treated with ultrasound thrombolysis and Amplatz thrombectomy device (ATD). Four patients with arterial occlusive disease of Fontaine stage IIb-III underwent intraarterial ultrasound-thrombolysis, applied to long segmental occlusions of the superficial femoral or iliac artery ranging in duration from three days to one year. RESULTS: The weight of the thrombi after ultrasound thrombolysis was 1.5 g +/- 0.53 (ATD: 0 g) compared to 3.65 g +/- 0.34 without treatment, with more weight reduction in five-day-old thrombi than in one-day-old thrombi. In vivo, partial recanalization was achieved in a three-day-old femoral occlusion. There was no effect in the other three patients. Urokinase thrombolysis with subsequent PTA and stenting resulted in complete recanalization in three patients. CONCLUSIONS: Ultrasound thrombolysis in vitro was significantly less effective than ATD. The results of ultrasound thrombolysis were influenced by the age of the thrombus and its in vitro formation. Intravascular ultrasound thrombolysis alone was insufficient to treat occluded peripheral arteries in vivo.
RATIONALE AND OBJECTIVE: With the progress of interventional procedures the need for retrieval of iatrogenic materials increases. Here we introduce a new nitinol micro-forceps for retrieval of intravascular objects and report our first in-vitro experiences. MATERIALS AND METHODS: In a tube model simulating arterial anatomy a total of eight endovascular coils were removed from the "carotid artery" using a "trans-femoral" approach. Additionally, the withdrawal of grasped coils through vascular sheaths of F-5, F-6, F-8, F-12 was observed (n = 4/seize). RESULTS: Seven of 8 coils were successfully grasped. Loss of one coil occurred during retrieval. Withdrawal of coils through a vascular sheath was possible only when the coil was grasped at one of its ends. DISCUSSION: The nitinol micro-forceps proved to be a potential tool in endovascular retrieval of foreign objects especially in small caliber vessels. However, further technical modifications are necessary to improve maneuverability and grasping strength.
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The adipocyte-derived hormone, leptin, has been implicated in the regulation of appetite, weight gain and glucose homeostasis as well as in liver fibrogenesis, hematopoiesis and immune function. No previous reports have clearly defined pathologically elevated or decreased serum leptin levels for Caucasian adults. The aim of this study was to define and characterize subjects with relative hyper- and hypoleptinemia in a large population-based German cohort. Percentiles of leptin levels by body mass index (BMI) were calculated from 4971 adult Germans, and the participants with leptin levels above the 95th and below the 5th percentile were defined as relatively hyperleptinemic and relatively hypoleptinemic, respectively, for their BMI. These participants were compared with the intermediate group with respect to anthropometric and clinical data and parameters of glucose and iron metabolism, lipid status, renal, adrenal and reproductive function. Relatively hyperleptinemic participants (HL) showed higher insulin, c-peptide, and total cholesterol levels than the hypoleptinemic subjects; in males, ferritin levels were higher and testosterone levels lower in the HL group. In conclusion, we report the first percentile curves for serum leptin by BMI in a large Caucasian population. Relatively low leptin values may be associated with a lower metabolic risk than relatively high serum leptin values.
We describe the first clinical application of T-cell-recruiting bispecific antibodies directly into the tumor without the need to preactivate the effector cells. In a Phase I clinical trial, 10 patients with low-grade B-cell lymphoma were treated by a single locoregional injection of CD3xCD19 bispecific antibodies. Costimulatory signaling, which is required for the optimal activation of resting T cells, was provided by the simultaneous administration of CD28 antibodies. Equal amounts of both antibodies were injected together at 4 different dose levels (30 microg: 3 patients; 270 microg: 3 patients; 810 microg: 3 patients; 1,600 microg: 1 patient). The injection was well tolerated with mild to moderate adverse effects (2/10 patients) consisting of erythema and fever at the third dose level. The maximum tolerated dose was not reached at 810 microg of injected antibodies. Three patients showed a serum peak of TNFalpha on day 2 or 3 after the antibody application, reflecting rather an activation of CD4-positive T cells than an FcR-mediated effect. Five patients developed anti-mouse antibodies after injection of the murine immunoglobulins. Nine patients were evaluable for restaging examinations 6 weeks after the antibody application, with 2 of them (22%) showing a local clinical response. We found that a single locoregional injection of CD3xCD19+CD28 antibodies is feasible up to a dose of at least 1,600 microg of each antibody. However, the development of human anti-mouse antibodies points toward the requirement for new formats of bispecific proteins with reduced immunogenicity.
We report three adenomatous middle-ear tumours, an adenoma, an adenocarcinoma and a semimalignant adenomatous tumour, with special attention to CT and MRI findings. In all cases we found small intratympanic masses in which the ossicles were embedded. All showed contrast enhancement and similar signal intensity as brain tissue on T1- and T2-weighted images. The biological nature of the tumours was not reflected by the imaging or operative findings.
The purpose of this study was to investigate the effect of fluvastatin on the microcirculation of patients with hyperlipidaemia (low-density lipoprotein cholesterol > 160 mg/dL, triglycerides < 350 mg/dl) inadequately controlled by diet. After a dietary run-in of 4 weeks, patients were randomised in a double-blind study to receive fluvastatin 40 mg twice daily (n = 24) or placebo (n = 24) for 12 weeks. The effect on microcirculation was assessed using capillary microscopy and laser Doppler fluxmetry at the nailfold at baseline and at 6 and 12 weeks after initiation of therapy. Capillaroscopy showed that fluvastatin improved microcirculation, i.e. time to peak flow during postocclusive reactive hyperaemia dropped from 19.7 +/- 7.2 s at baseline to 12.3 +/- 9.5 s at week 6 (P < 0.01) and 10.6 +/- 6.5 s at week 12 (P < 0.0001). These results were confirmed using laser Doppler fluxmetry to study microcirculation in thermoregulatory capillaries at the same site. A significant decrease in total and LDL-cholesterol was achieved during fluvastatin therapy. In conclusion, fluvastatin therapy improves microcirculation in nutritive as well as thermoregulatory capillaries in hypercholesterolaemic patients within 6 weeks.
PURPOSE: Evaluation of the efficacy of direct current and laser therapy in the treatment of colorectal liver metastases in a rat model. MATERIALS AND METHODS: Liver metastases in 49 rats were induced by subcapsular injection of cells of a colorectal tumor cell line. 3 weeks after inoculation 41 tumors were treated by laser and 56 tumors by direct current therapy. 17 tumors served as a control in the direct current group, 12 in the laser therapy group. The inoculation rate and the tumor size 3 and 5 weeks after therapy were determined by MRI. RESULTS: The MR-tomographically determined inoculation rate was 133 tumors after 151 tumor cell injections (88%). Three and five weeks after laser therapy, tumor growth rates of 15% and 18% were documented (maximum tumor diameter). This represented a significant reduction in growth (p < or = 0.01 and p < or = 0.001) compared to the control group (growth rate 230% and 280%). In the direct current therapy group, growth rates were 40% after 3 and 60% after 5 weeks. Compared to the control group (210% and 290%), this also represented a significant reduction (p < or = 0.001). CONCLUSIONS: This animal study is the first to demonstrate an antitumor effect of direct-current therapy on liver metastases of colorectal cancer in rats. Nevertheless, the laser therapy proved to be more effective.
PURPOSE: Evaluation of MR imaging and CSF flow measurement for planning and follow-up of neuroendoscopic third ventriculostomy in occlusive triventricular hydrocephalus. METHOD: 17 patients with occlusive hydrocephalus due to idiopathic or neoplastic aqueductal stenosis were examined before and after surgery with cardiac-gated T2-weighted and cardiac-gated phase contrast cine sequences. The visibility of anatomic structures and the patency of the ventriculostomy were evaluated. RESULTS: In all 17 patients, the relevant anatomic structures were visible. The cine sequence demonstrated occlusion of the aqueduct and patency of the ventriculostomy in all cases, even in patients with doubtful clinical patterns. CONCLUSIONS: MR imaging with additional cardiac-gated cine sequences allows exact preoperative diagnosis of occlusive hydrocephalus as well as patient selection and planning for endoscopic third ventriculostomy. Non-invasive follow-up, especially in patients with a doubtful clinical pattern, is possible.