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B Risius

Publications and source records attributed to B Risius.

At least 37 records · Page 2Linked to original sources
PubMed1986

Peripheral artery and bypass graft thrombolysis with recombinant human tissue-type plasminogen activator.

Recombinant tissue-type plasminogen activator (t-PA) is a DNA-synthesized thrombolytic agent recently approved for clinical trials. We present the results of t-PA infusions in 18 patients with thrombosed peripheral arteries (12 patients) and peripheral bypass grafts (six patients). The duration of occlusion ranged from 1 to 21 days (mean, 6.8 days). Infusions of t-PA were done by way of an intra-arterial approach at a dose of 0.1 mg/kg/hr. All patients demonstrated thrombus lysis angiographically. Fifteen of 18 (83%) had clinical as well as angiographic improvement. Secondary procedures to maintain patency of the arterial segment were required in seven patients. No complications occurred that were related to the t-PA infusion. No significant prolongation of the prothrombin, thrombin, or activated partial thromboplastin times occurred. At the end of t-PA infusion, the mean circulating fibrinogen level was 59% of the starting value. The therapeutic use of t-PA is still in its preliminary stages and the efficacy and safety of this promising agent need to be further established. From our early experience with t-PA, it appears to be safe as well as effective.

Adult↗
PubMed1986

A prospective analysis of the accuracy and cost-effectiveness of digital subtraction angiography for living-related renal donor evaluation.

From 1982 to 1984, we conducted a prospective study to evaluate the usefulness of i.v. renal digital subtraction angiography (DSA) for living-related donor (LRD) evaluation. Twenty-eight LRDs were evaluated with the traditional approach of intravenous pyelography (IVP) and standard catheter arteriography (SCA) (group 1). During the same period, 33 LRDs underwent renal DSA and IVP from a single i.v. contrast injection (group 2). If renal arterial imaging with DSA was considered satisfactory, no further radiographic studies were done (group 2-A, n = 23). If renal arterial imaging with DSA was not satisfactory, SCA was then obtained (group 2-B, n = 10). DSA alone accurately defined the number and location of renal arteries in 21 of 23 patients from group 2-A, and in 5 of 10 patients from group 2-B. The major limitation of DSA was in patients with multiple renal arteries; accurate imaging was obtained in only 7 of these 13 patients (54%). In group 2 overall, preoperative renal imaging was not accurate in 2 of 33 patients (6%); in both cases, an unsuspected polar artery was found at nephrectomy. The mean cost per patient of all radiographic renal imaging studies was $953.00 for group 2 and $1721.00 for group 1. These data suggest that the approach of preferentially evaluating LRDs with DSA-IVP, and obtaining SCA only if DSA yields poor visualization, is more cost-effective but not as accurate as the traditional policy of obtaining SCA and IVP in all cases.

Angiography↗
PubMed1986

Recombinant human tissue-type plasminogen activator for thrombolysis in peripheral arteries and bypass grafts.

Recombinant human tissue-type plasminogen activator (rt-PA) was infused intraarterially at 0.1 mg/kg/h for 1-6 1/2 hours in 25 patients with lower extremity thromboembolic occlusions (13 thrombosed arteries, 12 thrombosed bypass grafts). Occlusion duration ranged from 1 hour to 21 days. Thrombolysis occurred in 23 of 25 patients (92%). Time to lysis varied from 1 to 6.5 hours, with an average time of 3.6 hours. Twenty of 23 patients (87%) in whom thrombolysis was successful benefited clinically from thrombolytic therapy. Twelve of 23 patients (52%) required secondary procedures to maintain arterial segment patency. In 15 of 25 patients (60%) fibrinogen levels were maintained above 50% of baseline values. No major complications directly attributable to rt-PA infusions occurred. rt-PA is a potent, relatively fibrin-specific thrombolytic agent that can achieve rapid thrombolysis while usually avoiding the profound systemic fibrinogenolysis associated with currently available thrombolytic agents.

Adult↗
PubMed1986

Thrombolysis with recombinant human tissue-type plasminogen activator in patients with peripheral artery and bypass graft occlusions.

Thirty-three patients with thrombosed peripheral arteries and bypass grafts, as confirmed by angiography, were treated with recombinant human tissue-type plasminogen activator (rt-PA). Twenty-six patients were treated with a dose of 0.1 mg/kg/hr and seven patients with 0.05 mg/kg/hr. Thrombus lysis and clinical improvement occurred in 22 of 26 (85%) patients in the 0.1 mg/kg/hr group. In seven of seven (100%) patients in the 0.05 mg/kg/hr group angiographic as well as clinical improvement were observed. Fifteen of the 33 patients required anticoagulation to maintain patency. Sixteen required secondary procedures to maintain patency. One (3%) patient required a blood transfusion for a hematoma at the catheter entry site. Three other patients developed small hematomas that were controlled without transfusion or intervention. Sixty-one percent of patients treated with the 0.01 mg/kg/hr dose and 86% of patients treated with the 0.05 mg/kg/hr dose maintained fibrinogen levels greater than 50% of their initial values. Infusion durations ranged from 1 to 6 hr (mean 3.9 hr). rt-PA appears to be a potent and selective thrombolytic agent that rapidly and safely lyses thrombi in peripheral arteries and occluded bypass grafts.

Adult↗
PubMed1985

Digital subtraction angiography for evaluating patients with renal carcinoma.

Intravenous digital subtraction angiography has been performed on 39 patients with renal carcinoma. In 19 patients (group 1) imaging of the renal arteries was done following injection of 40 cc intravenous contrast medium through an antecubital vein. In 20 patients (group 2) 40 cc intravenous contrast medium were injected through a femoral vein and digital subtraction imaging of the inferior vena cava was obtained. In 12 of these patients the renal arteries also were visualized from the same injection of contrast medium. Intra-arterial digital subtraction angiography of the renal arteries also was done in 5 patients in group 2. Intravenous digital subtraction angiography satisfactorily demonstrated main renal arterial anatomy in 29 of 35 patients (83 per cent) over-all but failed to delineate the renal mass in most cases. Excellent visualization of the inferior vena cava was obtained in all 20 patients in group 2. Intraarterial digital subtraction angiography yielded an accurate diagnosis of renal carcinoma in all 5 patients with minimal doses of contrast medium. We conclude that intravenous digital subtraction imaging combined with computerized tomography scanning or ultrasonography yields satisfactory diagnostic and anatomical information for most patients with renal carcinoma.

Angiography↗
PubMed1985

Local thrombolysis in the treatment of thrombosed arteries, bypass grafts, and arteriovenous fistulas.

We reviewed the results, systemic effects, and complications associated with the selective infusion of low-dose streptokinase in 151 patients. Successful thrombus lysis was achieved in 78% of atherosclerotic thrombotic occlusions less than 30 days old, in 81% of post-procedural occlusions less than 14 days old, and in 87% of patients with thrombosed arteriovenous fistulas no more than 4 days old. During the first 12 hours of treatment 81% to 84% of patients had greater than 50% decrease in plasma fibrinogen levels and 100% showed the same decline after 24 hours of treatment. The thrombin time was prolonged to at least 1 1/2 times the control thrombin time in 33% to 42% of patients measured at 4 hours of therapy and in 93% to 97% of patients measured at 24 hours of treatment. Fifteen patients (9.9%) had major complications. Eleven of these had hemorrhagic complications, two had significant distal emboli, one had a thrombosed brachial artery, and one had a false aneurysm at the catheter entry site. We have found that selective low-dose streptokinase is effective in the treatment of acute and chronic thrombotic occlusions and is a useful adjuvant to vascular reconstruction or percutaneous transluminal angioplasty. Although the local infusion dose is substantially lower than the usual systemic dose, a systemic lytic effect was seen in all patients. Hemorrhagic complications occurred despite customary precautions.

Aged↗
PubMed1985

Thoracic aortic dissections: magnetic resonance imaging.

Six patients with documented dissections of the thoracic aorta (two Type A, four Type B) were examined by magnetic resonance (MR) imaging using a 0.6-Tesla superconductive magnet. Cardiac gating was applied in five cases. Correlation was made with CT and angiography. MR imaging demonstrated the dissection in all six cases and accurately differentiated Type A from Type B dissections. Coronal and sagittal MR sections were advantageous in establishing the relationship of the three arch vessels to the dissection. In addition, cardiac-gated MR was useful in demonstrating mural thrombus and in distinguishing the true from the false lumen based on differences in signal intensity resulting from different flow rates. In five cases, the information obtained by MR was equal to or surpassed that obtained by CT. In the one case of a completely thrombosed dissection, the CT scan was more helpful. MR should become an important imaging modality in the evaluation of aortic dissections.

Adult↗
PubMed1985

Percutaneous extraction of renal calculi.

Percutaneous procedures have rapidly gained widespread acceptance for the management of most patients requiring removal of renal calculi. Included in this review is a detailed description of currently applicable techniques.

Dilatation↗
PubMed1984

Catheter-directed low dose streptokinase infusion: a preliminary experience.

Fifty-six patients with acute or chronic arterial or venous thromboembolic occlusions received treatment with low dose (5,000 U per hour) streptokinase via an indwelling intravascular catheter. Successful clot lysis was achieved in 13 of 14 (92%) postprocedural occlusions that were less than one week in age, in 8 of 11 (73%) atherosclerotic occlusions that were less than six weeks in age, in 2 of 3 (67%) emboli from cardiac thrombi, and in all of the pulmonary emboli and superior vena cava occlusions. In the chronic occlusions, successful thrombus lysis occurred less frequently (8 of 21, 38%). Although the initial objective of fibrinolytic therapy is clot lysis, the long term clinical success depends on the diagnosis and treatment of the underlying cause of the thromboembolism.

Adult↗
PubMed1984

Low-dose streptokinase for selective thrombolysis: systemic effects and complications.

The systemic effects and complications associated with the infusion of low-dose (5,000 U/hr) intravascular streptokinase were reviewed in 159 patients. Eighty-two percent of the patients had a 50% decrease in plasma fibrinogen levels during the first 4 hours of treatment, and 100% of the patients showed the same decline following 12 hours of treatment. The thrombin time was prolonged to at least 1 1/2 times the control thrombin time in 42% of the patients at 4 hours of treatment and in 92% at 24 hours of treatment. The rate or degree of change in fibrinogen levels or prolongation of the thrombin time did not correlate with the incidence of complications. Seventeen patients (10.7%) suffered major complications. Thirteen of the 17 had hemorrhagic complications, three had thrombotic or embolic complications, and one had a false aneurysm. In this series, systemic effects occurred in all patients. It is concluded that, despite precautionary measures, hemorrhagic complications may occur. Steps should be taken to minimize complications, including careful observation of the patient and monitoring of plasma fibrinogen levels until adequate regeneration is complete.

Aneurysm↗
PubMed1984

Magnetic resonance imaging of renal transplants.

Nineteen patients were examined to determine the clinical potential of magnetic resonance imaging (MRI) for evaluation of renal transplants. A 0.6-T cryogenic magnet and spin-echo technique with varying pulsing factors were used. T1-weighted images were best for differentiating the cortical and medullary parts of the transplanted kidney. Of the six living-related transplants with good renal function that were imaged, five demonstrated good corticomedullary differentiation (CMD) and one faint CMD. Three transplants with acute rejection were imaged, and all demonstrated a decrease in CMD and decrease in overall signal intensity compared with baseline. No CMD was seen in the three chronically rejecting transplants imaged. The appearance of cadaveric transplants and acute tubular necrosis was quite variable. All perinephric fluid collections were well depicted by MRI. Lymphoceles could be distinguished from hematomas. MRI may prove to be a useful adjunct in the evaluation of renal transplants and perinephric fluid collections.

Adolescent↗
PubMed1982

Sector computed tomographic spine scanning in the diagnosis of lumbar nerve root entrapment.

The diagnosis of lumbar nerve root entrapment was made by sector computed tomography (CT) scanning in 25 patients whose myelograms were normal at the site of the CT scan abnormalities. Sector CT scanning demonstrates preoperatively which neural foramina are narrow. This information, correlated with the patient's history and physical examination, indicates which foramina should be operated on and prevents unnecessary exploration of normal neural foramina. CT findings were confirmed surgically in 14 patients. Eleven of these 14 patients had excellent postoperative results and remain pain free.

Adult↗
PubMed1981

Visualization of the arteries, veins, and nerves of the orbit by sector computed tomography.

Altering the scintillation crystal configuration of a fixed-detector CT scanner increased the spatial resolution from 6.25 to 10 line pairs per centimeter. Sector scans of th orbit with this modified scanner showed the ophthalmic artery and superior ophthalmic vein and their branches and the intraorbital branches of the third, fifth, and sixth nerves, apparently seen with CT for the first time.

Humans↗