Using a peptide inhibitor of the glycoprotein IIb/IIIa platelet receptor: initial experience in patients with acute peripheral arterial occlusions

OBJECTIVE: The purpose of this study was to evaluate the efficacy of eptifibatide, an inhibitor of the glycoprotein (GP) IIb/IIIa platelet receptor, in the thrombolytic treatment of patients with acute peripheral arterial occlusive disease. MATERIALS AND METHODS: We retrospectively reviewed our experience with the use of a GP IIb/IIIa receptor inhibitor, eptifibatide, during thrombolysis in 17 patients with acute lower extremity arterial occlusions who also received intraarterial recombinant tissue plasminogen activator (rt-PA) and heparin. Four of the 17 patients received their loading dose of eptifibatide by direct intraarterial injection, whereas the remaining 13 received an IV loading dose. We compared their results with those of 11 other patients who received only rt-PA and heparin with respect to success and complication rates, duration of thrombolytic therapy, and total rt-PA dose. RESULTS: We found no significant difference in successful outcome (p = 1.00), major complications (p = 1.00), duration of therapy (p = 0.21), or total rt-PA dose (p = 0.67) between those who received eptifibatide and those who did not during thrombolytic therapy. However, those patients who received an intraarterial loading dose of eptifibatide required substantially less rt-PA (9.0 +/- 4.4 mg vs 38.9 +/- 30.7 mg) to achieve successful thrombolysis. CONCLUSION: The adjunctive use of a GP IIb/IIIa platelet receptor inhibitor during thrombolysis for arterial occlusions may decrease the total dose of rt-PA required for thrombolysis without compromising success or complication rates. A prospective randomized study is needed to confirm that inhibitors of the GP IIb/IIIa platelet receptor can facilitate thrombolytic therapy in patients with acute lower extremity arterial occlusions.     

Can catheter-directed thrombolysis be applied to acute lower extremity artery embolism after recent cerebral embolism from atrial fibrillation?

PURPOSE: To assess the feasibility and efficacy of catheter-directed thrombolysis with recombinant tissue plasminogen activator (rt-PA) for acute limb embolism in patients with recent cerebral embolism due to atrial fibrillation. MATERIALS AND METHODS: Eight patients (six men, two women; mean age 63.5 years) with acute embolic occlusion of two left common iliac arteries, four femoral arteries (three left; one right), and two right popliteal arteries were treated. All patients had a history of recent cerebral embolism (mean 6 days, range 5-15 days) and all had a history of atrial fibrillation (duration 5-10 years). Catheter-directed thrombolysis started a few hours (mean 6.2h; range 3-10h) after the onset of arterial embolism. Two 5mg boluses of rt-PA were injected into the proximal clot through a 5 F end-hole catheter and, subsequently, two additional boluses of 5mg rt-PA were injected into the emboli. In patients with residual emboli, infusion with rt-PA (1mg/h) was continued. Percutaneous transluminal angioplasty was performed in three patients, and a stent was deployed in one patient. RESULTS: Technical success was achieved in all patients. Clinical success rate was 87.5% (7/8). The one clinical failure was secondary to chronic occlusion of outflow runoff vessels. The mean duration of continuous rt-PA infusion was 3.6h, the mean total dose of rt-PA administered was 23.6mg (range 20-28mg). There was no significant change in stroke scale scores during thrombolysis and no intracerebral haemorrhage was found at computed tomography (CT) after thrombolysis. Minor complications included haematomata at puncture sites (6/8), bleeding around the vascular sheath (2/8), and haematuria (1/8). During the follow-up period of 3-6 months, one patient suffered from recurrent cerebral embolism and died. CONCLUSIONS: Catheter-directed thrombolysis with rt-PA is an option for acute lower extremity arterial embolism in patients with recent cerebral embolism and a history of atrial fibrillation. Further studies should be undertaken to determine the risk of intracerebral haemorrhage caused by catheter-directed thrombolysis in individual stroke patients.     

Thrombosed dialysis grafts: efficacy of intrathrombic deposition of concentrated urokinase, clot maceration, and angioplasty

Forty-one thrombosed polytetrafluoroethylene hemodialysis grafts in 26 patients were treated by a modified method of fibrinolytic therapy and transluminal angioplasty. The modifications included the use of highly concentrated urokinase, intrathrombic injection of urokinase into mechanically macerated thrombi, use of a crossed two-catheter technique, observation of the patient in the angiography suite during the entire procedure, and transluminal angioplasty to correct underlying stenosis immediately after partial or complete thrombolysis. Lysis was initially successful in 37 (90%) of 41 procedures. Successful treatment, defined as a functional graft for longer than 6 months without intervening surgery, was achieved in 16 (62%) of 26 patients. In comparison with previous transluminal or surgical regimens, this modified method permits marked acceleration of thrombolysis, immediate transluminal angioplasty, and sparing of potential future graft sites.     

Thrombolysis and the femorofemoral bypass graft: a new technique.

Two patients with acutely thrombosed femorofemoral bypass grafts are presented. Recombinant human tissue-type plasminogen activator (rt-PA) was used successfully in thrombolysis of the occluded grafts. Utilizing a new technique the grafts were punctured directly and bolus doses of rt-PA administered.     

Transcatheter Thrombolysis with High-Dose Bolus Tissue Plasminogen Activator in Iatrogenic Arterial Occlusion after Femoral Arterial Catheterization

Purpose: To assess the efficacy of percutaneous local thrombolysis with high-dose bolus recombinant tissue plasminogen activator (rt-PA) in patients with acute limb ischemia due to arterial thrombosis after cardiac catheterization. Methods: We treated eight patients (7 men; mean age 56 years) with thrombotic occlusion of both the common femoral artery (CFA) and external iliac artery (EIA) in six patients and of the CFA only in two patients. Two 5 mg boluses of rt-PA were injected into the proximal clot through a 5 Fr end-hole catheter and subsequently two additional boluses of 5 mg rt-PA were given through a catheter with multiple side-holes. In case of a significant amount of residual thrombus, a continuous infusion of 2.5 mg/hr of rt-PA was started. Results: Successful lysis was achieved in all patients. The mean duration of lysis was 2 hr 41 min. The mean total amount of rt-PA delivered was 23.16 mg. In four patients unmasked flow-limited dissections confined to the CFA were managed by prolonged balloon dilatation, while in the remaining four patients with extension of the dissection to the external iliac artery one or two Easy Wallstents were implanted. There was prompt relief of lower limb ischemic symptoms and signs in all patients. Two groin hematomas were conservatively treated. Clinical and color Doppler flow imaging follow-up with a mean duration of 15 months, showed no reappearance of ischemic symptoms or development of restenosis in any of the patients. One patient died 6 months after thrombolysis. Conclusions: Transcatheter thrombolysis with high-dose bolus rt-PA is a safe and effective treatment in patients with iatrogenic arterial occlusion after femoral catheterization. Underlying dissections should be treated by prolonged balloon dilatation but stent implantation is often required.     

Bleeding complications associated with the use of rt-PA versus r-PA for peripheral arterial and venous thromboembolic occlusions

This article analyzes the early experience with alteplase (rt-PA) and reteplase (r-PA) to identify noteworthy differences in bleeding and to determine correlations with dosage, concomitant anticoagulation, and duration of infusion. A retrospective review of the medical records was unavailable for the initial 82 patients who were treated with either rt-PA (44) or r-PA (38) for peripheral arterial or venous occlusions after urokinase therapy. Successful recanalization was achieved in 31/44 (70%) of the patients treated with rt-PA and in 34/38 (89%) of the patients treated with r-PA. Significant bleeding was documented in 20/44 (45%) of the rt-PA-treated patients (including 14 transfusions) versus 3/38 (8%) of the r-PA-treated patients (3 transfusions). Concomitant anticoagulation with either preceding warfarin (international normalized ratio > 1.1) or a bolus of heparin at the outset of the infusion was associated with significant bleeding in 13/17 (76%) of the rt-PA-treated patients (including 9 transfusions) versus 0/17 in the r-PA-treated patients. No significant correlation between either mean dose or total dose and bleeding was shown for either drug. Early experience indicates that r-PA is at least as effective as rt-PA for the thrombolysis of peripheral arterial and venous occlusions. It also appears that r-PA is less likely than rt-PA to be associated with significant bleeding during such infusions, especially if the patient is concomitantly anticoagulated.     

Outcome after catheter-directed thrombolysis of occluded prosthetic femoropopliteal bypasses. A prospective study

Purpose: To evaluate the outcome after catheter-directed thrombolysis of occluded femoropopliteal prosthetic bypasses with the distal anastomosis above the knee.Material and Methods: Twenty-one patients were included in this prospective study. End-hole catheters, a bolus dose and continuous infusion of recombinant tissue-plasminogen activator (rt-PA) were used, with a median total dose of 10 mg (range 7-20 mg).Results: With an intra-thrombotic position of the catheter, total or subtotal lysis was obtained in 19 of 21 patients (90%). No serious complications occurred. In 9 patients, the stenoses were successfully treated with balloon angioplasty (PTA, n=5), local thrombectomy/extension of bypass (n=3), or with a new bypass (n=1). After a median observation time of 18 months (6-24), 5 patients had open bypass. Re-occlusion occurred in all (6/6) bypasses in which no flow-limiting lesion was discovered, in all (4/4) bypasses treated twice with thrombolysis, as well as in all bypasses in which stenoses had not been adequately treated (3/3). One bypass re-occluded immediately due to poor runoff.Conclusion: In the present study, 19/21 infra-inguinal prosthetic bypasses were successfully treated with catheter-directed thrombolysis. However, re-occlusion often took place, especially in bypasses without flow-limiting lesions. If re-occlusion occurs in a bypass in which no stenoses were revealed during the primary thrombolysis procedure, a second catheter-directed thrombolytic treatment does not seem to be warranted. Our results confirm that treatment of flow-limiting lesions is a prerequisite for maintaining patency.     

Catheter-directed thrombectomy and thrombolysis for acute renal vein thrombosis

PURPOSE: To evaluate the technical success and clinical outcome of the percutaneous treatment of acute renal vein thrombosis (RVT). MATERIALS AND METHODS: Retrospective review was conducted of all patients with acute RVT treated with percutaneous catheter-directed thrombectomy with or without thrombolysis at one institution between 2000 and 2004. Demographics, comorbid conditions, and clinical outcomes associated with therapy were assessed. RESULTS: Seven thrombosed renal veins in six patients (mean age, 51.5 +/- 18.8 years) were treated with percutaneous catheter-directed thrombectomy/thrombolysis. Thrombosed renal veins included two allografts and five native veins, and diagnosis was confirmed in all cases by direct renal venography. Inferior vena cava thrombosis was the cause of RVT in one patient, and glomerulopathy was the cause in the remaining patients. Percutaneous mechanical thrombectomy was performed in all cases, and five renal veins were additionally treated with thrombolysis for a mean duration of 22.1 +/- 21.0 hours. Restoration of flow to renal veins was achieved in all thrombosed renal veins. Clinical improvement occurred in all patients: the mean serum creatinine level improved from a preoperative level of 3.3 +/- 1.92 mg/dL to a postoperative level of 1.92 +/- 1.32 mg/dL (P = .008). Mean glomerular filtration rate improved from a preoperative level of 30.8 +/- 23.0 mL/min per 1.73 m(2) to 64.2 +/- 52.4 mL/min per 1.73 m(2) (P = .04). There were no pulmonary emboli or hemorrhagic complications, and no RVT recurrence was documented during a median follow-up of 22.5 months. CONCLUSIONS: Percutaneous catheter-directed thrombectomy with or without thrombolysis for acute RVT is associated with a rapid improvement in renal function and low incidence of morbidity. It is feasible for native and allograft renal veins and should be considered in patients with acute RVT, particularly in the setting of deteriorating renal function.     

Pharmacomechanical thrombolysis and angioplasty in the management of clotted hemodialysis grafts: early and late clinical results.

The results of pharmacomechanical thrombolysis and angioplasty of 121 thrombosed hemodialysis grafts were reviewed. The initial pharmacomechanical method (used in 65 cases) employed clot maceration with hook-shaped catheters and clot lacing with highly concentrated urokinase. The current technique (used in 56 cases) consisted of pulsed-spray injection of urokinase into the clot. All fully treated grafts (117 cases) underwent complete or near-complete thrombolysis, and 93% remained patent after 1 day. Mean time for pulsed-spray lysis was 46 minutes +/- 21. One patient (less than 1%) had gastrointestinal bleeding and received a transfusion; minor complications occurred in 3% of patients. Primary and secondary graft patency rates for both methods at 1 year were 26% and 51%, respectively. While graft age and results of angioplasty did not influence future graft patency, shorter intervals between graft thromboses was predictive of earlier subsequent graft failure. Results suggest that pharmacomechanical thrombolysis and angioplasty provide rapid, consistent, and safe recanalization of clotted hemodialysis grafts and represent a promising additional therapeutic approach to long-term graft management.     

Pharmacomechanical thrombectomy of acute deep vein thrombosis with the Trellis-8 isolated thrombolysis catheter

PURPOSE: To evaluate the performance of the Trellis-8 isolated thrombolysis catheter during single-session pharmacomechanical thrombectomy (PMT) combined with low-dose thrombolysis with tissue plasminogen activator (TPA) in the treatment of patients with acute deep vein thrombosis (DVT) and multiple comorbidities. MATERIALS AND METHODS: Retrospective analysis was performed of 19 consecutive patients with acute above-knee DVT treated by PMT with the Trellis device followed by venous angioplasty and stent placement. Isolated thrombolysis with low-dose TPA was used with all patients. Concurrent therapies included retrievable inferior vena cava filter insertion (n = 4). The primary endpoint was restoration of rapid inline venous flow; the secondary endpoint was thrombus clearance. RESULTS: Restoration of rapid inline venous flow was achieved in all cases; thrombus removal was less than 50% in one case (4%), 50%-95% in 18 cases (82%), and at least 95% in three cases (14%). The median administered dose of TPA was 13.4 mg per patient. The mean treatment time was 91 minutes per limb (range, 61-129 min), with a mean of 21 minutes per thrombosed segment (range, 8-31 min). There were no major complications. Primary patency rate of the treated venous segments at 2 days was 86% (n = 19) and the primary assisted patency rate was 100% at 30 days. Two patients died of advanced malignancy at 17 and 24 days. CONCLUSIONS: The Trellis system was an effective method for the treatment of acute DVT. Based on the present data, the Trellis system could prove to be a safe and feasible single-session PMT method for the treatment of acute DVT in a broader patient population and warrants further investigation in a large-scale study.     

Weight-based rt-PA thrombolysis protocol for acute native arterial and bypass graft occlusions.

PURPOSE: To determine technical success and complications with weight-adjusted dosing of recombinant tissue plasminogen activator (rt-PA) for arterial and bypass graft occlusions. MATERIALS AND METHODS: During an 8-month period, prospective data were collected on patients undergoing catheter-directed thrombolysis. Retrospective review of all medical charts and blood bank data were performed for confirmation. All patients underwent a standard weight-adjusted protocol for catheter-directed thrombolysis. Thrombolytic therapy with rt-PA (0.2 mg/mL) was defined as low-dose when 0.02 mg/kg/h rt-PA was used and high-dose when 0.04 mg/kg/h of rt-PA was used. Low-dose heparin therapy was used. Total infusion time, total dose, and hourly rate of dose were calculated. Technical success, defined as complete removal of all clot without surgical intervention, complications, and frequency of transfusions were tabulated. RESULTS: A total of 35 patients underwent catheter-directed thrombolysis with rt-PA, including a total of 21 bypass grafts (60%) and 14 native arteries (40%). Mean age was 57 years (+/- 22.5; range, 3 mo to 83 y). Average rate of heparin infusion was 472.8 U/h (+/- 227). Success rates for graft thrombolysis were 90% (18 of 21). Success rates for native vessels were 79% (11 of 14). In patients who underwent only a low-dose protocol, the transfusion rate was 15% and major complications were 10%. In patients with a combined low-dose/high-dose administration, the transfusion rate was 46% and major complications were 13%. Overall success rate and major complication rates were 86% (30 of 35) and 11% (four of 35), respectively. Frequency of transfusions was 37% (13 of 35; mean, 2.8 U). CONCLUSION: Although weight-adjusted dosing for rt-PA provides a high efficacy of relieving ischemia, the rate of complications, especially bleeding, seems excessive in comparison to historical experience with urokinase. Administration of short-term high doses of rt-PA did not appear to have any beneficial effect. Further investigation with lower dosing and concentration should be considered.     

Thromboembolism complicating thrombin injection of femoral artery pseudoaneurysm: management with intraarterial thrombolysis

Ultrasound (US)-guided compression of pseudoaneurysms is being rapidly replaced by US-guided percutaneous treatment with thrombin injection because of the less intensive nature of this procedure. Thromboembolism after percutaneous treatment with thrombin injection is rare and has been described in brachial artery pseudoaneurysms. These were managed with intravenous administration of heparin and surgical thrombectomy. In this report, the authors describe thromboembolic complication of thrombin injection after treatment of a femoral artery pseudoaneurysm. This was managed by intraarterial thrombolysis with use of recombinant tissue plasminogen activator (rt-PA) with resolution of all major occlusive changes. A lower dose of thrombin injection and frequent postprocedural monitoring of distal pulses is recommended.     

Transcatheter intraarterial infusion of rt-PA for acute lower limb ischemia: results and complications

PURPOSE: To determine the success and complication rates of intraarterial recombinant tissue-type plasminogen activator (rt-PA) infusion for the treatment of acute lower extremity artery and bypass graft occlusions. MATERIALS AND METHODS: The results of 74 limbs in 70 patients (mean age, 66 y) treated with catheter-directed rt-PA infusion for the treatment of acute lower extremity ischemia were retrospectively evaluated. The group included 42 bypass grafts and 32 native arteries. All limbs were viable at presentation. The mean duration of symptoms was 11.9 days. rt-PA was infused for a mean of 27.9 hours for a mean total dose of 38.7 mg. Initial infusion rates of 3-6 mg/h were lowered to a preferred rate of 1.5 mg/h. Thrombolytic success was defined as 95% thrombolysis of an occluded segment with return of antegrade flow. Major bleeding complications were defined as any hemorrhagic event leading to surgery, extended or unexpected hospitalization, transfusion, death, intracranial hemorrhage, or a decrease in hemoglobin of 5 g/dL or in hematocrit of 15%. Thirty-day mortality and amputation rates were calculated. Patient characteristics and infusion parameters were evaluated as to whether they contributed to thrombolytic success or major bleeding events. RESULTS: Thrombolytic success was achieved in 64 limbs (86%). Major bleeding complications occurred in 33 (47%) patients. In 22 of these patients, bleeding occurred at a vascular puncture site, whereas remote bleeding occurred in seven patients. Remote bleeding complications included two retroperitoneal hematomas, two rectus sheath hematomas, one lower gastrointestinal hemorrhage, one episode of hemoptysis, and one dehiscence of a femoral-popliteal bypass graft revision. No parameters were found to be predictive of thrombolytic success, whereas a negative history of smoking, increasing duration of infusion, and a low preprocedural ankle-brachial index (ABI) were found to be associated with major hemorrhagic events. Four patients (6%) underwent amputation and one patient (1%) died, resulting in a 30-day amputation-free survival rate of 93%. CONCLUSION: Catheter-directed rt-PA infusion is effective in achieving thrombolysis. Despite a significant number of bleeding complications, 30-day mortality and amputation rates were favorable. Nonetheless, complication rates related to bleeding were not trivial and further evaluation with use of variable dosing regimens is indicated.     

Treatment of hemodialysis catheter-associated fibrin sheaths by rt-PA infusion: critical analysis of 124 procedures

PURPOSE: To prospectively evaluate the efficacy of a low-dose, 3-hour infusion of recombinant tissue plasminogen activator (rt-PA) for the treatment of hemodialysis catheter (HDC)-associated fibrin sheaths. This report expands the authors' experience with this technique over that previously reported. MATERIALS AND METHODS: Fifty-five patients with end-stage renal disease (38 women, 17 men) undergoing catheter-directed hemodialysis treatment were evaluated for 124 episodes of HDC dysfunction. This patient group had a mean age of 57 years and an age range of 23-92 years. Radiographic contrast studies and/or clinical evaluation were consistent with the presence of a fibrin sheath on the arterial and/or venous port in all cases. Each patient underwent a thrombolytic infusion consisting of 2.5 mg rt-PA in 50 mL normal saline at 17 mL/h (3-hour infusion) per port. All infusions were performed in the interventional radiology recovery room on an outpatient basis. Patients were followed prospectively for technical success, complications, catheter patency, and long-term outcome. RESULTS: The technical success rate, defined as return of effortless manual aspiration and infusion capability from both ports followed by at least one successful dialysis session, was 91%. No patient was excluded from rt-PA therapy because of contraindications, and the procedure-related complication rate was zero percent. A Kaplan-Meier survival analysis yielded primary patency rates at 30, 60, 90, and 120 days of 0.55, 0.36, 0.25, and 0.15 (SE <.10), respectively; secondary patency rates at 60, 120, 180, and 240 days were 0.70, 0.46, 0.30, and 0.27 (SE <.10), respectively (P < 001). At the end of the study period, all 52 surviving patients continued to undergo catheter-directed hemodialysis and 34 (65%) were using the same catheter present at the time of entrance into the study. Of the 18 patients (35%) requiring catheter exchange, 16 (89%) did for persistent malfunction after rt-PA therapy, one (5.5%) for infection, and one (5.5%) for a fractured hub. CONCLUSION: Thrombolytic therapy with use of a 2.5-mg rt-PA infusion through each port over a 3-hour period would appear to be a safe method for treating HDC-associated fibrin sheaths. Immediate return of catheter function is achieved in most patients, obviating more invasive techniques. Primary patency rates are relatively short, but catheters that fail can be retreated, resulting in secondary patency rates that are substantial and significantly improved.     

Sequestrated thrombolysis: Comparative evaluation in vivo

Purpose: Lysis of a thrombus is a function of the local concentration of thrombolytic enzymes. This study was designed to determine in a porcine model of acute deep vein thrombosis (DVT) whether perithrombic sequestration of small volumes of a concentrated enzyme solution can accelerate the process of thrombolysis. Methods: DVT was induced in both hind limbs using a previously described technique (n = 32). Thirty minutes later the animal was heparinized and unilateral thrombolysis was attempted using 8 mg recombinant tissue plasminogen activator (rt-PA); saline was administered in the opposite leg. For conventional high-volume infusion (CI) (n = 5) rt-PA (0.067 mg/ml) was infused at 1 ml/min. For sequestrated thrombolysis the external iliac vein was endoluminally occluded, and rt-PA (0.25 mg/ml) administered either for proximal injection (ST-P) (n = 5), as a bolus every 3 min through a microcatheter placed via the balloon catheter, or for transthrombic injection (ST-T) (n = 5), as a bolus every 3 min through a Katzen wire in the balloon catheter. At autopsy, the thrombus mass in the iliofemoral veins was measured, and the extent of residual thrombosis in the venous tributaries graded at four sites. From these data a thrombolysis score was calculated. Results: One pig died before thrombolysis could be performed. Only with ST-T was residual thrombus mass in the test limb normalized to control, residual thrombus index (RTI), consistently less than unity. The median RTI of this group was 0.50 (range 0.39–0.97) compared with 1.22 (0.64–1.38) for ST-P and 0.88 (0.37–1.13) for CI. Compared with contralateral controls, a lower grade of residual thrombosis in tributaries was observed in test limbs at more venous sites with ST-T (8/20; 95% confidence interval 5–13) and ST-P (9/20; confidence interval 5–13) than with CI (2/20; confidence interval 0–5) (p= 0.04). A trend toward lower thrombolysis scores was observed with ST-T (p = 0.08). Systemic fibrinogenolysis was not observed in any of the groups. Changes in coagulation parameters during thrombolysis were similar irrespective of treatment protocol. Conclusions:“Transthrombic” sequestrated thrombolysis may offer some advantages over conventional selective infusion for the treatment of acute DVT. However further refinements will be necessary before it can be considered an alternative to the latter.     

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.     

Dialysis Access Graft Thrombolysis: Randomized Study of Pulse-Spray Versus Continuous Urokinase Infusion

Purpose: To compare pulse-spray to continuous-infusion thrombolysis with high-dose urokinase in thrombosed dialysis access grafts. Methods: A prospective randomized controlled trial was performed. From August 1992 to September 1993, 30 thrombosed polytetrafluoroethylene (PTFE) grafts in 24 patients were included, 15 grafts in each group. The success of thrombolysis, mean time to thrombolysis, mean urokinase dose, and 60-day patency rate were evaluated. Results: In the pulse-spray group, the mean time to thrombolysis was 72 min with a mean urokinase dose of 560,000 U. The 60-day patency rate was 71%. In the continuous-infusion group, the mean infusion time to thrombolysis was 55 min with a mean dose of 479,000 U. The 60-day patency rate was 73%. Conclusion: No statistically significant difference was found between the two techniques in the mean time to thrombolysis, the mean urokinase dose used, or the 60-day patency rate.     

Catheter-directed thrombolysis with the Endowave system in the treatment of acute massive pulmonary embolism: a retrospective multicenter case series

PURPOSE: To evaluate the efficacy of thrombolysis with the EndoWave peripheral infusion system in the treatment of patients with massive pulmonary embolism (PE) as compared to patients treated with catheter-directed thrombolysis. MATERIALS AND METHODS: Ten patients (five men and five women; age range, 31-85 years; mean age, 54.20 years) with massive acute PE (17 lesions) were treated with ultrasonography (US)-assisted catheter-directed thrombolysis with the Endowave system. All patients had hypoxia and dyspnea. No patient had contraindication for thrombolysis. Angiographic findings, duration of lysis, dose of thrombolytics used, and procedural complications were recorded. Thrombolytics used were urokinase, tissue-type plasminogen activator (tPA), and Reteplase. RESULTS: Complete thrombus removal was achieved in 13 of the 17 lesions (76%), near complete thrombolysis was achieved in three lesions (18%), and partial thrombolysis was achieved in one lesion (6%). The mean time of thrombolysis was 24.76 hours +/- 8.44 (median, 24 hours). The mean dose of tPA used for the Endowave group was 0.88 mg/h +/- 0.19 (13 lesions). CONCLUSIONS: US-assisted catheter-directed thrombolysis is an effective method for treating massive thrombolysis. It has the potential to shorten the time of lysis and lower the dose of thrombolytics.     

Direct endovascular thrombolytic therapy for dural sinus thrombosis: infusion of alteplase.

PURPOSETo evaluate the efficacy, safety, and results of direct thrombolytic therapy in intracranial dural sinus thrombosis by infusion of alteplase (recombinant tissue plasminogen activator).METHODSNine patients were treated during a 2-year period for intracranial dural sinus thrombosis. A microcatheter was placed directly into the thrombus in the dural sinus via the transfemoral route. Thrombolysis was initiated with a rapid injection of 10 mg of alteplase over 10 minutes, followed in 3 hours by a continuous infusion of 50 mg, then a continuous infusion at 5 mg per hour until complete thrombolysis or a total dose of 100 mg per day had been reached. Repeat thrombolysis was tried the following day if complete recanalization did not occur at 100 mg per day.RESULTSSuccessful recanalization with improvement of symptoms was achieved in all cases. Time required for complete thrombolysis was between 8 and 43 hours. The total dose of alteplase ranged from 50 to 300 mg. Complications of a small intrapelvic hemorrhage and oozing at a femoral puncture site occurred in separate cases, but were not related to the amount of infused alteplase. MR venograms obtained 1 to 4 weeks after the procedure showed no evidence of reocclusion of the dural sinuses.CONCLUSIONDirect fibrinolytic therapy with alteplase is safe, fast, and effective in treating dural sinus thrombosis. However, to prevent hemorrhagic complications, further studies are required to determine its optimal dose and proper rate of administration.     

rt-PA Thrombolysis in Acute Thromboembolic Upper-Extremity Arterial Occlusion

Purpose: Retrospective analysis of the results of rt-PA thrombolysis in the treatment of acute thromboembolic occlusion of the upper limb. Methods: Of 55 patients with demonstrated acute embolic arterial occlusion, rt-PA thrombolysis was performed on 40 occlusions in 38 patients (23 women with a mean age of 62 years, range 32–85 years; 15 men with a mean age of 65 years, range 32–92 years) according to the following design: 6 mg rt-PA/hr for 30 min, 3 mg rt-PA/hr for the next 30 min, 1 mg rt-PA/hr for 7 hr, and 0.4 mg rt-PA/hr until the end of lysis. Onset of symptoms varied from 1 to 14 days. Included were three isolated upper-arm occlusions, nine combined brachial and forearm occlusions, and 28 forearm and hand artery occlusions. Results: The overall success rate was 55%. The lysis results for isolated upper arm, combined brachial and forearm occlusions, and forearm and hand artery occlusions were 100%, 66%, and 46%, respectively. In eight patients surgical embolectomy had to be performed after failed thrombolysis. No amputation was required in the follow-up period. No lethal complications occurred. Conclusions: Interventional rt-PA treatment of proximal upper-extremity arterial occlusions may be performed with comparable success rates to surgical embolectomy and without severe complications. For distal occlusions the results are inferior to the success rates obtained with surgery.