Management of pulmonary thrombo-embolism using catheter manipulation: a report of four cases and review of the literature.
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To date the management of pulmonary thrombo-embolism is still largely limited to anticoagulation. Heparin and oral anticoagulation have been shown to be effective in reducing recurrence and death in venous thrombo-embolism. During the acute stage, systemic thrombolytic therapy has also been advocated for the rapid dissolution of the thrombus in patients with haemodynamic instability. We describe four patients with acute pulmonary thrombo-embolism who were managed with catheter-based thrombus manipulation with intrapulmonary thrombolysis. This management strategy should be considered in patients with pulmonary thrombo-embolism who continue to deteriorate despite conventional management with anticoagulation or systemic thrombolysis. (+info)
Ventricular rate control during atrial fibrillation by cardiac parasympathetic nerve stimulation: a transvenous approach.
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OBJECTIVES: To identify intravascular sites for continuous, stable parasympathetic stimulation (PS) in order to control the ventricular rate during atrial fibrillation (AF). BACKGROUND: Ventricular rate control during AF in patients with congestive heart failure is a significant clinical problem because many drugs that slow the ventricular rate may depress ventricular function and cause hypotension. Parasympathetic stimulation can exert negative dromotropic effects without significantly affecting the ventricles. METHODS: In 22 dogs, PS was performed using rectangular stimuli (0.05 ms duration, 20 Hz) delivered through a catheter with an expandable electrode-basket at its end. The catheter was positioned either in the superior vena cava (SVC, n = 6), coronary sinus (CS, n = 10) or right pulmonary artery (RPA, n = 6). The basket was then expanded to obtain long-term catheter stability. Atrial fibrillation was induced and maintained by rapid atrial pacing. RESULTS: Nonfluoroscopic (SVC) and fluoroscopic (CS/RPA) identification of effective intravascular PS sites was achieved within 3 to 10 min. The ventricular rate slowing effect during AF started and ceased immediately after on-offset of PS, respectively, and could be maintained over 20 h. In the SVC, at least a 50% increase of ventricular rate (R-R) intervals occurred at 22 +/- 11 V (331 +/- 139 ms to 653 +/- 286 ms, p < 0.001), in the CS at 16 +/- 10 V (312 +/- 102 ms vs. 561 +/- 172 ms, p < 0.001) and in the RPA at 18 +/- 7 V (307 +/- 62 ms to 681 +/- 151 ms, p < 0.001). Parasympathetic stimulation did not change ventricular refractory periods. CONCLUSIONS: Intravascular PS results in a significant ventricular rate slowing during AF in dogs. This may be beneficial in patients with AF and rapid ventricular response since many drugs that decrease atrioventricular conduction have negative inotropic effects which could worsen concomitant congestive heart failure. (+info)
Long-term results after recanalisation of chronic iliac artery occlusions by combined catheter therapy without stent placement.
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OBJECTIVES: to evaluate the long-term outcome after recanalisation of chronic iliac artery occlusions by combined catheter therapy without stent placement. DESIGN: retrospective study. MATERIAL AND METHODS: between 1979 and 1995 75 consecutive patients were treated (53 men, 22 women; mean age 63.1+/-13.7 years; mean length of the occluded segment 6.9+/-3.5 cm). The indication for treatment was incapacitating claudication (n=55) or chronic critical ischaemia (n=20). At follow-up clinical data, pulse volume and pressure measurements were recorded and duplex-sonography and/or angiography performed, if clinically indicated. RESULTS: mean follow-up was 7. 2+/-4.1 years. The primary clinical success rate was 64% at 12 months, 57% at 4 years and remained stable for up to ten years. The secondary clinical success rate after 12 months was 83% and remained stable at 81% for up to 10 years. Peripheral embolisation as complication of the intervention occurred in 18 patients (24%) and was treated by percutaneous thromboembolectomy in 15 patients during the same procedure. In the remaining three patients no intervention was necessary. One patient had to undergo surgery for a groin haematoma. CONCLUSIONS: recanalisation of segmental chronic iliac artery occlusions by catheter therapy without stent placement has favourable long-term results comparable to primary stent placement. Randomised controlled studies are required to determine the appropriate role of catheter therapy alone and primary or selective stenting for iliac artery occlusions. (+info)
Methods of obtaining peripheral venous access in difficult situations.
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Peripheral venous access is frequently required in the hospital environment. This can occasionally be difficult to obtain. We have reviewed the pertinent literature and propose a structured algorithmic approach to reduce patient discomfort and to minimise the time involved in securing venous access. (+info)
Expanded indications for ultrasound-guided thrombin injection of pseudoaneurysms.
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PURPOSE: We previously reported preliminary data on a new procedure that we developed for the treatment of femoral pseudoaneurysms after catheterization. This study presents our current results of percutaneous ultrasound-guided thrombin injection for treating pseudoaneurysms that arise from various locations and causes. METHODS: Between February 1996 and May 1999, we performed thrombin injection of 83 pseudoaneurysms in 82 patients. There were 74 femoral pseudoaneurysms: 60 from cardiac catheterization (36 interventional), seven from peripheral arteriography (four interventional), five from intra-aortic balloon pumps, and two from dialysis catheters. There were nine other pseudoaneurysms: five brachial (two cardiac catheterization, two gunshot wounds, one after removal of an infected arteriovenous graft), one subclavian (central venous catheter insertion), one radial (arterial line), and one distal superficial femoral and one posterior tibial (both after blunt trauma). Twenty-nine pseudo-aneurysms were injected while on therapeutic anticoagulation. Patients underwent repeat ultrasound examination within 5 days and after 4 weeks. RESULTS: Eighty-two of 83 pseudoaneurysms had initial successful treatment by this technique, including 28 of 29 in patients who were undergoing anticoagulation therapy. The only complication was thrombosis of a distal brachial artery, which resolved spontaneously. There were early recurrences in seven patients: four patients underwent successful reinjection; reinjection failed in two patients, who underwent surgical repair; and one patient had spontaneous thrombosis on follow-up. After 4 weeks, ultrasound examinations were completely normal or showed some residual hematoma, and there were no recurrent pseudoaneurysms. CONCLUSION: Ultrasound-guided thrombin injection of pseudoaneurysms has excellent results, which support its widespread use as the primary treatment for this common problem. (+info)
Vascular remodeling and the local delivery of cytochalasin B after coronary angioplasty in humans.
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OBJECTIVES: This study sought to determine the safety, feasibility and outcome of local delivery of cytochalasin B at the site of coronary angioplasty. BACKGROUND: Previous failures in the pharmacologic prevention of restenosis may have been related to inadequate dosing at the angioplasty site as a result of systemic drug administration. Alternatively, although previous experimental protocols have typically targeted control of excess tissue growth (intimal hyperplasia), it now appears that overall arterial constriction (vascular remodeling) is the major contributor to late lumen loss. Cytochalasin B inhibits the polymerization of actin and has proved to be a potent inhibitor of vascular remodeling in animal models. METHODS: In this phase I, multicenter, randomized, controlled trial, cytochalasin B (or matching placebo) was administered to the site of a successful balloon angioplasty using a microporous local delivery infusion balloon. RESULTS: The rate of drug delivery at a constant infusion pressure varied significantly from patient to patient (range 1.7 to 20.2 ml/min), perhaps related to a variable constricting effect of the atherosclerotic plaque on the infusion balloon. The minimal stenosis diameter after the procedure was slightly better in the active drug group (1.86 +/- 0.44 vs. 1.49 +/- 0.63 mm, p < 0.03), but this difference was not seen at four to six weeks. Although the study was not powered for clinical outcomes (n = 43), the combined end point (death, nonfatal infarction or repeat revascularization) was encountered in 20% of the patients receiving cytochalasin B and in 38% of the patients receiving placebo. Clinical restenosis occurred in 18% of the treatment group and 22% of the placebo group. There were no significant differences between groups in biochemical or electrocardiographic variables. CONCLUSIONS: Cytochalasin B can be safely administered by local delivery after successful coronary angioplasty and warrants further study of its efficacy in reducing restenosis. (+info)
Popliteal vein entrapment: a benign venographic feature or a pathologic entity?
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PURPOSE: Asymptomatic morphologic popliteal vein entrapment is frequently found in the healthy population (27%). In our institution, popliteal vein compression on plantar flexion was observed in 42% of all ascending venograms. Some authorities consider the lesion benign, without pathologic significance. This study examines the pathophysiologic importance in select patients, describes treatment with surgery, and suggests a diagnostic tool. METHOD: Thirty severely symptomatic patients with venographic evidence of popliteal entrapment were selected to have popliteal vein release after a process of elimination (ie, other causes of chronic venous insufficiency [CVI] were ruled out by means of comprehensive hemodynamic and morphologic studies). In the last nine limbs, popliteal vein pressure was also measured by means of the introduction of a 2F transducer tip catheter. Patients were clinically and hemodynamically assessed before and after surgery, and anatomical anomalies encountered during surgery were recorded. RESULTS: Popliteal vein release was performed without mortality or serious morbidity. Anomalies of the medial head of the gastrocnemius muscle caused entrapment in 60% of the patients; anatomic course venous anomalies were infrequent (7% of the patients). Significant relief of pain and swelling occurred in the patients who had surgery. Stasis ulceration/dermatitis resolved in 82% of patients. Popliteal venous pressures had normalized in the six patients who were studied postoperatively. CONCLUSION: Popliteal vein entrapment should be included in the differential diagnosis of CVI in patients in whom other, more common etiologies have been excluded on the basis of comprehensive investigations. Popliteal vein compression can be demonstrated venographically in a large proportion of patients with CVI, but the lesion is likely pathological only in a small fraction of these patients. A technique for popliteal venous pressure measurement is described; it shows promise as a test for functional assessment of entrapment. Immediate results of popliteal vein release surgery are encouraging; long-term follow-up is necessary to judge the efficacy of surgical lysis of entrapment in symptomatic patients who fail to improve with conservative treatment measures. (+info)
Nitroglycerin to control blood pressure during endovascular stent-grafting of descending thoracic aortic aneurysms.
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Temporary asystole induced with adenosine or electrically induced ventricular fibrillation has previously been proposed to prevent hypertension during transluminal placement of thoracic endovascular stent-grafts. Nitroglycerin is a safe and less invasive alternative to control blood pressure and, in contrast to the methods mentioned, can also be used during stent-grafting performed under local anesthesia. (+info)