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Biomedical subjects

H Schwarzenberg

Publications and source records attributed to H Schwarzenberg.

34 records · Page 2Linked to original sources
PubMed1996

[Results of percutaneous implantation of coated vascular prostheses in long-distance femoropopliteal occlusions].

PURPOSE: Evaluation of primary patency rate, complications and midterm follow-up after implantation of endoprostheses in femoropopliteal occlusions. MATERIAL AND METHODS: 25 patients suffering from femoropopliteal occlusion (average length 7 cm) underwent percutaneous femoropopliteal endoprosthesis treatment. A total of 34 endoprostheses were implanted. Clinical and Doppler follow-up was performed after 1, 3, 6 and 9 months. Mean follow-up is 6 months. RESULTS: Percutaneous placement of endoprostheses was successful primarily in 24/25 patients. In one patient an early occlusion of the endoprosthesis occurred, caused by an embolic complication. Primary patency was 64% after 6 months and secondary patency rate was 71%. Severe local pain at the application site and fever was observed in 40% of the patients. CONCLUSION: The occlusion rate of 36% after 6 months is high. Long-term follow-up must be awaited before a general recommendation can be made. The cause of the local pain and fever in the early postinterventional period remains unclear.

Adult↗
PubMed1996

[Mechanical thrombolysis with the Amplatz thrombectomy catheter].

PURPOSE: To determine the efficiency of the Amplatz thrombectomy device (ATD) in thromboembolic occlusions of lower limb arteries and haemodialysis shunts. PATIENTS AND METHODS: 9 patients (mean age 61 years) with either occluded native leg arteries (n = 7) or haemodialysis graft access (n = 2) were treated with the ATD. Mean length of occlusion was 10 +/- 4.47 cm. RESULTS: The occlusions were primarily successfully recanalized by ATD within 44 +/- 17 seconds. Remaining stenoses were treated with percutaneous transluminal angioplasty (PTA, n = 6) and an additional implantation of a vascular stent (n = 3). The ankle-brachial-index (ABI) increased from 0.46 +/- 0.37 to 0.81 +/- 0.2 within 24 hours after intervention. In the first month ABI measured 0.9 +/- 0.15 and decreased from 0.7 +/- 0.23 after three months to 0.72 +/- 0.26 within 6 months. After 5 months, a shunt occlusion and a native leq artery occlusion appeared. CONCLUSIONS: Thrombolysis by ATD is a safe, feasible and simple procedure. There are no contraindications. No complications were seen.

Adult↗
PubMed1996

[Modified manual rt-PA pulse-spray lysis in occlusions of leg arteries and femoro-popliteal bypasses].

PURPOSE: The evaluation of local rt-PA pulse-spray-lysis (PSL) by the Katzen infusion wire for treatment of thrombosed leg arteries and bypass grafts. MATERIAL AND METHOD: 21 patients (mean age 64.4 years) with either occluded leg arteries (n = 19) or femorocrural bypass grafts (n = 2) were treated with PSL. Mean length of occlusion was 13.2 +/- 11.6 cm. Time of occlusion ranged from less than one week to 6 months. RESULTS: In 71.43% (15/21) the occlusions could be successfully recanalized with PSL. The mean rt-PA dose was 10.7 +/- 4.9 mg. Remaining stenoses were handled with PTA (n = 9) and additional stent implantation (n = 3). Additional long-time-lysis with 17.5 mg rt-PA was necessary in two cases, the success rate increased to 81% (17/21). The anlde-brachial-index increased from 0.38 +/- 0.29 to 0.83 +/- 0.32 within 24 hours after intervention. In 4 cases bleeding complications occurred. 5 patients showed reocclusions during 6 months follow-up. CONCLUSIONS: Local fibrinolysis with rt-PA in PSL technique using the Katzen infusion wire is a feasible and promising treatment of thrombosed leg arteries and grafts. Even careful and dosage-minimized rt-PA application cannot prevent bleeding complications.

Adult↗
PubMed1996

Effect of intraarticular pressure on patellar position. Computed tomography study in cadaveric specimens.

RATIONALE AND OBJECTIVES: The purpose of the study was to evaluate the effect of articular fluid distention on patellar position at different degrees of knee angulation. METHODS: Patellar position in 10 cadaveric knee specimens was determined with 30, 100, and 200 mm Hg joint distention at 45, 20, and 5 degrees of knee flexion using computed tomography. Patellar tilting and lateromedial and anteroposterior displacement of the patellar position were analyzed. RESULTS: Lateral tilting increased with greater articular distention and decreasing knee flexion. At 5 degrees of flexion and 200 mm Hg of distention, change in lateral tilting ranged from -7 to +5 degrees. At 45 degrees of flexion and increased distention, the patellar shift ranged from 6 mm medialization to 1 mm lateralization for 200 mm Hg, but the patellar position was more variable at 5 degrees of flexion with increasing intraarticular pressure (range 7 mm medialization to 8 mm lateralization). With increasing articular pressure the patellae were increasingly displaced anteriorly with the most pressure-dependent changes at 45 and 20 degrees of knee flexion. CONCLUSIONS: Fluid distentions of the knee joint have unpredictable and varying effects on the patellar position and vary considerably among persons. When judging patellar position during arthroscopy and in patients with large joint effusions, the arthroscopist and radiologist should be aware of these effects.

Aged↗
PubMed1996

[The initial results of percutaneous therapy of popliteal aneurysms with stents].

PURPOSE: Are percutaneous stents a therapeutic alternative to bypass surgery in the treatment of popliteal aneurysms? MATERIAL AND METHODS: Three patients with femoropopliteal occlusion related to popliteal aneurysms were treated percutaneously. In two cases coated stents were used. In the third patient who underwent prior bypass surgery due to local fibrinolysis a reperfusion of the aneurysm occurred. He was treated with a Wallstent. RESULTS: Primary stent treatment was successful in all cases. There were no complications. One patient was lost to follow-up. One of the two coated stents occluded after one month due to a poor run-off of only one lower limb artery. The other coated stent is still patent after 6 months proven by angiography. CONCLUSION: Percutaneous therapy with coated stents could be an alternative to surgical bypass therapy for popliteal aneurysms. Obviously long-time patency is related to sufficient run-off.

Aged↗
PubMed1996

[CT-guided punctures: diagnostic value, therapeutic consequences and economic aspects].

PURPOSE: To evaluate the diagnostic and clinical relevance and therapeutic consequences of CT-guided biopsy with regard to economic aspects. METHODS: 213 CT-guided biopsies in 190 patients were evaluated. All information regarding patient referral, reason for request, body region, underlying diagnosis, and clinical consequences were registered over a period of 22.2 +/- 9.4 month. RESULTS: Patient referral to biopsy was mainly from the departments of surgery, internal medicine, and radiotherapy with the question of tumor and metastasis. Less than 5% of biopsies were performed in outpatients. Main regions were the lung (39%), the abdomen (35%), and the skeleton (11%). Biopsy and surgical histology corresponded in 73%. Largest diagnosis groups were benign unspecific tissues or other benign lesions in 24%. As a result of CTP no further procedures were necessary in 22.5%. Follow-up studies or conservative treatment were indicated in 11.3%. Surgical procedures were needed in only 15.5%. There was only one complication requiring therapy. CONCLUSION: CT-guided biopsy is a safe procedure, which helps to avoid unneccessary cost-intensive diagnostics and surgical treatment. If CTP is performed early and in outpatients residence time in the hospital is reduced and thus money is saved.

Adult↗
PubMed1995

[A modified technic for local rt-PA catheter-mediated lysis].

PURPOSE: To develop an economic and efficient concept for more time-saving local rt-PA thrombolysis therapy. METHOD: 40 patients with peripheral vascular occlusive disease stage IIb-III according to the Fontaine classification and with angiographically proven occluded segments of pelvic and lower limb arteries were treated by a modified concept of local rt-PA catheter thrombolysis. Via a thin guide wire the catheter for thrombolysis is slowly advanced through the thrombus without fluoroscopic control, outside the room in which angiography is performed. In 24 cases a short-term lysis and in 16 cases a long-term lysis was carried out. RESULTS: The initial success rate was 75%, the patency rate in six months' follow-up was 66.7%. The ankle-brachial index decreased from 0.4 +/- 0.3 to 0.8 +/- 0.2 on the average. There were no relevant clinical complications. The average occupancy time of the angiography room or table was 60 +/- 52 min, the average time of fluoroscopy was 17 +/- 13 min. CONCLUSION: In modified local rt-PA thrombolysis, short-term lysis and long-term lysis were mostly performed outside the angiography room, so that the exposure to radiation and there fore the radiation dose were reduced for both the patient and the attending staff. The angiography room is thus available for other patients and can therefore be used more efficiently.

Adult↗
PubMed1995

[Castleman's disease: evaluation of 338 cases].

PURPOSE: To evaluate a large group of patients with Castleman's tumours (Castleman's disease = MC) with regard to age, sex and tumour localisation. PATIENTS AND METHODS: 338 cases of MC were evaluated. All cases were registered by the Lymphknotenregister of the German Society of Pathology, Kiel. RESULTS: 292 MC of the hyaline vascular type (MC-HV) and 46 of the plasma cell type (MC-PC) were found, 259 (76.6%) in nodal and 79 (23.4%) in extranodal localisation. Main nodal localisation were the neck (25.5%) and the axilla (12.8%). The mediastinum was involved in only 6.2%. There was a slight preference of female (56%) compared to male (44%). Patients with MC-PC (mean age: 50 +/- 16.9 years) were significantly older (p < 0.001) than patients with MC-HV (mean age: 39 +/- 18.9 years). CONCLUSIONS: The main localisation of MC is the neck. MC-HV is more common than MC-PC. There is a slight preference for women. Mean age of patients with MC-PC is approximate 10 years higher than for MC-HV.

Adolescent↗
PubMedDate not supplied

Amplatz thrombectomy device: unexpected interaction with the Cragg endoprosthesis.

In a 74-year-old woman, a Dacron-covered Cragg endoprosthesis was implanted into the left superficial femoral artery after successful recanalization of a 6-cm-long occlusion. At 4.5 months after discharge the endoprosthesis was occluded. In order to perform a thrombectomy, an Amplatz thrombectomy device (ATD) was activated and advanced into the occluded graft. Suddenly, a mechanical failure of the ATD occurred. Extraction of the ATD was achieved only after repeated attempts at rotating motion and jerky pullback maneuvers. The most likely explanation is that one of the graft-struts had advanced into the tip of the ATD and resulted in a broken drive shaft. Recanalization was completed by performing percutaneous transluminal angioplasty and pharmacological thrombolysis with recombinant human-tissue plasminogen activator. In conclusion, users of the ATD have to be aware of interactions of the ATD with the struts of implanted stents or grafts during thrombectomy.

Aged↗
PubMedDate not supplied

Guidewire-controlled advancement of the Amplatz thrombectomy device.

The Amplatz Thrombectomy Device (ATD) is a percutaneous rotational catheter proven to homogenize thrombus. The catheter design allows neither application over a coaxial running guidewire nor the use of the device as a monorail system. We report a technical modification that provides guided advancement of the catheter over a wire in order to prevent failure of application and to facilitate the interventional procedure.

Angiography, Digital Subtraction↗
PubMedDate not supplied

Hyperthermic fibrinolysis with rt-PA: in vitro results.

PURPOSE: To investigate the influence of hyperthermia up to 45 degrees C on fibrinolysis with recombinant tissue-type plasminogen activator (rt-PA). METHODS: Standardized fibrin clots were incubated in a water bath for 5 hr with either rt-PA (test group) or 0.9% sodium chloride (control group) and blood plasma at temperatures of 30-45 degrees C. Concentrations of D-dimer and time to complete clot lysis were measured. RESULTS: The activity of fibrinolysis with rt-PA rose with increasing temperature: time to lysis approximately halved from 30 degrees C to 40 degrees C and the concentration of D-dimer tripled. In the control group clot size did not change. CONCLUSIONS: Activity of rt-PA-induced fibrinolysis rises distinctly with higher temperatures. Since even healthy subjects show a physiologic decline in body temperature in the extremities, in patients with occlusive arterial disease decreased activity of fibrinolysis with rt-PA can be expected. Controlled hyperthermia may improve fibrinolysis with rt-PA and should be investigated in vivo.

Fibrinolysis↗
PubMedDate not supplied

Percutaneous endoluminal stent and stent-graft placement for the treatment of femoropopliteal aneurysms: early experience.

PURPOSE: To determine the efficacy of percutaneous endoluminal stents and stent-grafts for the treatment of isolated femoropopliteal aneurysms. METHODS: Seven men (age 51-69 years) with femoropopliteal occlusions (n = 6) related to aneurysms and a patent femoropopliteal aneurysm (n = 1) were treated percutaneously. In two patients uncovered Wallstents and in five patients polyester-covered nitinol stents were implanted. Assessment was performed with Doppler ultrasound and duplex ultrasonography 24 hr, 1, 3, 6, 12, and 24 months after the intervention. Additionally, intraarterial angiography was performed at 6 months. RESULTS: Stent placement succeeded in all cases. No immediate adjunctive surgical treatment was necessary. Ankle-brachial index (ABI) improved from 0.29 +/- 0. 29 (SD) before to 0.78 +/- 0.23 (SD) 24 hr after the intervention. One patient was lost to follow-up. Stent-graft occlusion occurred in four patients: after 2 days (n = 1), 1 month (n = 2), and 3 months (n = 1). One of the patients, whose stent occluded at 1 month, underwent successful recanalization with local fibrinolysis therapy. Three of the seven, all with three-vessel run-off, demonstrated patency of the stent, which was assessed by duplex ultrasonography at 29, 31, and 34 months. Breaking of the stent struts or significant stent migration was not observed. CONCLUSIONS: These results in a small number of patients warrant further investigation to evaluate the role of percutaneous stents in femoropopliteal aneurysms. Until further data of clinical studies are available, this method cannot be recommended, and it cannot replace surgical treatment.

Aged↗
PubMedDate not supplied

Lower extremity occlusive disease: diagnostic imaging with a combination of cardiac-gated 2D phase-contrast and cardiac-gated 2D time-of-flight MRA.

PURPOSE: The goal of this work was to test the ability of a combination of 2D phase-contrast MR angiography (2D-PC-MRA) and triggered 2D time-of-flight MRA (2D-TOF-MRA) in comparison to intraarterial digital subtraction angiography (DSA) to correctly diagnose the location and shape of occlusive lesions in the iliac and femoral arteries and to determine whether 2D-TOF-MRA is helpful to clarify questionable lesions demonstrated by 2D-PC-MRA. METHODS: In 50 patients with claudication, 2D-PC-MRA was performed in three consecutive coronal positions from the aortic bifurcation to below the trifurcation. Axial 2D-TOF-MRA was performed additionally at the site of detected lesions of >50% and lesions in doubt to obtain more precise information about the stenosis. Lesions were classified as follows: low grade occlusion, <50%; high grade occlusion, >50%. MRA was performed within 24 h of a DSA examination. RESULTS: In all patients, the arterial tree from the aortic bifurcation to the trifurcation could be visualized. One hundred twelve lesions were detected by MRA. Sensitivity was 96% and specificity was 92%. Sixty-two lesions were classified as high grade occlusion and reevaluated. In this category, sensitivity was 100% and specificity was 96%. CONCLUSION: The combination of 2D-PC-MRA with triggered 2D-TOF-MRA detects stenotic lesions in the lower extremity arterial system with high sensitivity and specificity.

Adult↗