Thrombolytic therapy with recombinant human tissue-type plasminogen activator: a comparison of two doses

The efficacy and safety of two doses of recombinant human tissue-type plasminogen activator (rt-PA) were compared. Forty patients with peripheral arterial occlusions were treated with intraarterial rt-PA. Group A (n = 21) received 0.1 mg/kg/h, and group B (n = 19) received 0.05 mg/kg/h. Infusion durations varied from 4 to 8 hours. Complete thrombolysis occurred in 20 of 21 patients (95%) in group A and in all 19 patients (100%) in group B. In group A, fibrinogen levels were greater than 75% of baseline in ten of 21 patients (48%) at infusion termination. In group B, fibrinogen levels were greater than 75% of baseline in 12 of 19 patients (63%) at infusion termination. Three of 40 patients (7%) had significant complications resulting from rt-PA infusion. The results demonstrate that over similar infusion times, a dose of 0.05 mg/kg/h is as efficacious and results in less systemic fibrinogenolysis than a dose of 0.1 mg/kg/h.     

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.     

Efficacy and safety of radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia in the elderly

INTRODUCTION: Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common regular supraventricular tachycardia in the general population as well as in elderly patients. The purpose of the study was to investigate the success and complication rate particularly regarding the induction of an atrioventricular (AV) block by radiofrequency (RF) ablation in elderly patients with and without a preexisting AV block. METHODS AND RESULTS: Between February 1998 and July 2004, all patients with symptomatic AVNRT referred for slow-pathway ablation in our institution were included and divided into two groups: group 1 patients younger than 75 years (n = 508) and group 2 patients > or =75 years (n = 70). A preexisting prolonged PR interval was present in 17 (3.3%) patients of group 1 and in 26 (37%, P < 0.0001) patients of group 2. Following successful slow-pathway ablation (follow-up time group 1: 37 +/- 22, group 2: 37 +/- 24 months) no induction of an AV block was observed in group 2 but in four patients of group 1 (0.79%) a complete heart block was induced requiring a pacemaker implantation. In group 1, 15 (2.95%) patients with a recurrence of AVNRT were readmitted for a repeat ablation procedure. No recurrences occurred in group 2. CONCLUSION: Despite a higher incidence of preexisting prolonged PR intervals slow-pathway ablation in elderly patients is both effective and safe and should be considered as the first line therapy also in this patient population.     

Percutaneous treatment of urologic complications following renal transplantation

Summary Urologic complications continue to occur in renal transplant recipients. Furthermore, standard, secondary operative intervention for these problems has been associated with high morbidity and even mortality. Currently, percutaneous techniques are being used with increasing frequency for these patients to temporize or even avoid the need for subsequent operative procedures. The indications, techniques, and results of such intervention are reviewed.     

Role of percutaneous nephrostomy in patients with upper urinary tract transitional cell carcinoma

Percutaneous nephrostomy has become a well-established procedure for a wide variety of urologic disorders. However, its role in the management of patients with upper urinary tract transitional cell carcinoma has not been defined. We utilized percutaneous nephrostomy in 23 renal units for the evaluation or treatment of 21 patients in whom standard techniques were inconclusive or inadequate. The percutaneous nephrostomy provided adequate relief of obstruction in the face of significant azotemia or infection. Diagnostic abilities were improved through the use of antegrade pyelography, selective cytologic examination, and, at times, by providing direct access for endoscopic visualization and biopsy. In select cases, the percutaneous access provided a route for definitive or adjunctive treatment of the lesion. Complications were few and seeding of the tract or local tumor spread has not occurred at follow-up ranging from one to one hundred twenty-one (mean 27.8) months.     

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.     

Comparison of cost effectiveness of streptokinase and urokinase in the treatment of deep vein thrombosis

This study examines the comparative efficacy, safety, and cost associated with treatment of deep vein thrombosis with streptokinase or urokinase. Sixty patients were analyzed retrospectively, 30 treated with streptokinase and 30 treated with urokinase. Statistically significant greater fibrinogenolysis was noted when streptokinase was used to treat patients with deep venous thrombosis (p = 0.01). The mean decrease in fibrinogen from preinfusion value was 83% in the streptokinase treated group and 61% in the urokinase treated group. Five of 30 (17%) of the streptokinase treated patients experienced major complications. No major complications were seen in the urokinase treated group (p = 0.019). Cost analysis demonstrates that therapy with urokinase was $11.40 per patient more than streptokinase. If complications are not included in the cost analysis, then urokinase becomes only $650 per patient more expensive than streptokinase therapy. These data support that deep vein thrombosis treatment with urokinase is effective, safer and more cost efficient when compared to streptokinase.     

Transient ST-segment-elevation during pulmonary vein ablation using circumferential coiled microelectrodes in a prospective multi-centre study.

AIMS: Paroxysmal atrial fibrillation (PAF) is predominantly triggered by focal ectopies located within the pulmonary veins (PV). The BITMAP Study (Breakthrough and Isolation Trial: Mapping and Ablation of Pulmonary Veins) investigated prospectively the safety and efficacy of a catheter design with circumferential mapping and ablation electrodes. We report the phenomenon of ST-segment-elevation during catheter placement in the left atrium (LA) and superior PVs in this multi-centre study. METHODS AND RESULTS: Forty-three patients (57+/-10 years) with PAF were included in this study. Radiofrequency catheter (RFC) ablation supported by the 4F REVELATION Helix microcatheter (Cardima Inc., Freemont, CA, USA) with eight distal-coiled microelectrodes for bipolar mapping and ablation. RFC was applied at the ostial region of PV (30 W, 45-50 degrees C) with a maximum of four RFC applications per electrode. In four of the 43 patients from three centres, we recorded the occurrence of ST-segment-elevation greater than 0.2 mV and accompanying left thoracic discomfort. The ECG changes and the symptoms started abruptly and lasted for 4.2+/-2.2 min. Pericardial effusion could instantaneously be excluded by echocardiography in all cases. Coronary angiograms were performed in three patients with the longest episodes; no thrombotic material or air emboli were present. The symptoms and the ECG changes resolved completely in all patients. CONCLUSION: The phenomenon of ST-segment-elevation during LA- and PV-mapping in patients with PAF may be a common occurrence. In this prospective multi-centre trial, we demonstrated the reversibility of this phenomenon; no cardiovascular or cerebral damage was reported during both the procedure and the follow-up. Although the mechanism is still unclear, vasospasm may contribute to this phenomenon because of autonomic dysregulation.