Recombinant tissue plasminogen activator versus urokinase for local thrombolysis of femoropopliteal occlusions: a prospective, randomized multicenter trial

Early transcatheter thrombectomy and thrombolytic therapy in acute non-cirrhotic and non-malignant mesenteric vein thrombosis: Case report of two cases and literature review

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Non-cirrhotic non malignant acute mescenteric thrombosis could lead to massive bowel ischaemia and is challenging to manage.

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Conventional PV or SMV exploration is associated with significant blood lost, physiological disturbances and may need repeated procedures.

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Catheter directed thrombolysis and thrombectomy provide minimal invasive option to restore patency of PV or SMV.

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Literature review found high success rate and favourable outcome.

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Catheter directed therapy should be the first line therapy.

Aim

To present two cases of acute non-cirrhotic and non-malignant mesenteric vein thrombosis (MVT) treated with early transcatheter thrombectomy and thrombolysis with tissue plasminogen activator (tPA) and to review the literature on transcatheter thrombectomy and thrombolytic therapy of such condition.

Methods

Two cases of acute MVT treated with transhepatic transcatheter thrombectomy and thrombolysis in addition to systemic anticoagulation upon diagnosis are presented. In addition, a Pubmed literature search was undertaken using keywords acute mesenteric vein thrombosis, thrombolysis and thrombectomy. The inclusion criteria were studies examining the impacts of transcatheter thrombolysis and thrombectomy in the management of acute MVT.

Results

Early transcatheter thrombectomy and thrombolysis achieves technical success in both patients and result in nearly complete recanalization of the venous system, with no recurrent thrombosis to date in follow up. Both patients do not require extensive bowel resection despite extensive thrombus on presentation. However, both patients develop intra-abdominal bleeding requiring blood transfusion and embolization of the transcatheter tract.

Conclusion

Catheter-directed first approach provides a minimal invasive approach for management of non-malignant and non-cirrhotic acute mesenteric thrombosis. It offers the benefits of rapid venous recanalization and avoid massing bowel resection despite extensive thrombosis. Subsequent progression into chronic MVT was also reduced. However, the procedure could lead to bleeding from puncture site and hence embolization of the catheter tract is advised during catheter removal.

A systematic review and meta-analysis of endovascular and surgical revascularization techniques in acute limb ischemia

BACKGROUND

The initial treatment of patients with acute limb ischemia (ALI) remains undefined. The aim of this article was to compare the safety and effectiveness of catheter-driven thrombolysis (CDT) with surgical revascularization and evaluate the various fibrinolytic agents, endovascular, and pharmacochemical approaches that aim for thrombectomy.

METHODS

PubMed, Embase, and the Cochrane Library were searched for studies on the management of ALI by means of surgical or endovascular recanalization, returning 520 studies. All randomized, controlled trials, nonrandomized prospective, and retrospective studies were included comparing treatment of ALI.

RESULTS

Twenty-five studies, investigating a total of 4689 patients, were included for meta-analysis spread across nine different comparisons. No differences were found in limb salvage between thrombectomy and thrombolysis. More major vascular events were seen in the thrombolysis group (6.5% compared with 4.4% in the surgically treated group; odds ratio [OR], 0.33; 95% confidence interval [CI], 0.13-0.87; P = .02; I² = 20%). Comparable limb salvage was found for high- and low-dose recombinant tissue plasminogen activator (r-tPA). No significant differences were found in major vascular event between low r-tPA (14%) and high r-tPA (10.5%; P = .13). The 30-day limb salvage rate was 79.7% for r-tPA treatment and 60.4% for streptokinase (OR, 3.14; 95% CI, 1.26-7.85; P = .01; I² = 0%). AngioJet showed more limb salvage at 6 months compared with r-tPa (OR, 2.21; 95% CI, 1.17-4.18; P = .01; I² = 0%).

CONCLUSIONS

Both CDT and surgery have comparable limb salvage rates in patients with ALI; however, CDT is associated with a higher risk of hemorrhagic complications. No conclusions can be drawn regarding the risk of hemorrhagic complications regarding thrombolytic therapy by means of r-tPA, streptokinase, or urokinase. Insufficient data are available to conclude the preference of using a hybrid approach, ultrasound-accelerated CDT, heated r-tPA. or novel endovascular (rheolytical) thrombectomy systems. Future trials regarding ALI need to be constructed carefully, ensuring comparable study groups, and should follow standardized practices of outcome reporting.

Potential Benefits from Heating the High-Dose rtPA Boluses Used in Catheter-Directed Thrombolysis for Acute/Subacute Lower Limb Ischemia

Purpose:

To explore the potential benefits from heating recombinant tissue plasminogen activator (rtPA) before catheter-directed thrombolysis in patients with lower-limb ischemia of <30 days' duration.

Methods:

Over a 2-year period, 34 patients (26 men; mean age 63.5 years, range 39–80) with 10 iliac and 24 infrainguinal arterial occlusions (5 embolic and 29 thrombotic) were treated with two 5-mg boluses of rtPA injected into the proximal clot, followed by 2 additional 5-mg boluses of rtPA. In the first 18 patients (group A), room temperature rtPA was administered, whereas in the last 16 patients (group B), the rtPA boluses were heated to 38°C for 30 minutes before injection. Residual thrombus was treated with a continuous infusion of 2.5 mg/h of rtPA for 4 hours then at a reduced dose (1 mg/h).

Results:

Successful thrombolysis was achieved in 28 (82%) arteries. Unmasked lesions were treated with balloon angioplasty/stenting in 17 cases and with surgery in 4. One fatal retroperitoneal hematoma occurred in group A. Heating the rtPA did not significantly alter the outcome of thrombolysis. However, a statistically significant reduction in the total rtPA dose was observed in group B (24.28 mg versus 27.9 mg in group A, p = 0.05), as well as quicker lysis (2 hours, 42 minutes versus 6 hours, 12 minutes in group A, p = 0.001). There was no statistical difference in the amputation-free survival at 30 days between the groups.

Conclusions:

In patients with acute or subacute lower limb ischemia treated with catheter-directed thrombolysis, heating the rtPA results in faster lysis with a considerable reduction in the total dose of the lytic agent.

Fibrinolytic agents for peripheral arterial occlusion

BACKGROUND

Peripheral arterial thrombolysis is used in the management of peripheral arterial ischaemia. Streptokinase was originally used but safety concerns led to a search for other agents. Urokinase and recombinant tissue plasminogen activator (rt-PA) have increasingly become established as first line agents for peripheral arterial thrombolysis. Potential advantages of these agents include improved safety, greater efficacy and a more rapid response. Recently drugs such as pro-urokinase, recombinant staphylokinase and alfimperase have been introduced. This is an update of a review first published in 2010.

OBJECTIVES

To determine which fibrinolytic agents are most effective in peripheral arterial ischaemia.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched March 2013) and CENTRAL (2013, Issue 3) for randomised controlled trials (RCTs) comparing fibrinolytic agents to treat peripheral arterial ischaemia.

SELECTION CRITERIA

RCTs comparing fibrinolytic agents to treat peripheral arterial occlusion.

DATA COLLECTION AND ANALYSIS

Data were analysed for the outcomes vessel patency, time to lysis, limb salvage, amputation, death, complications including major haemorrhage, stroke, and distal embolization.

MAIN RESULTS

Five RCTs involving a total of 687 participants with a range of clinical indications were included. No new studies were included in this update. In one three-pronged study, vessel patency was greater with intra-arterial recombinant tissue plasminogen activator (rt-PA) than with intra-arterial streptokinase (P < 0.04) or intravenous rt-PA (P < 0.01). In participants with peripheral arterial occlusion there was no statistically significant difference in limb salvage at 30 days with either urokinase or rt-PA, though this may reflect the small numbers in the studies. Incidences of haemorrhagic complications varied with fibrinolytic regime but there was no statistically significant difference between intra-arterial urokinase and intra-arterial rt-PA. In the three-pronged study intravenous rt-PA and intra-arterial streptokinase were associated with a significantly higher risk of haemorrhagic complications than with intra-arterial rt-PA (P < 0.05).

AUTHORS' CONCLUSIONS

There is some evidence to suggest that intra-arterial rt-PA is more effective than intra-arterial streptokinase or intravenous rt-PA in improving vessel patency in people with peripheral arterial occlusion. There was no evidence that rt-PA was more effective than urokinase for patients with peripheral arterial occlusion and some evidence that initial lysis may be more rapid with rt-PA, depending on the regime. Incidences of haemorrhagic complications were not statistically significantly greater with rt-PA than with other regimes. However, all of the findings come from small studies and a general paucity of results means that it is not possible to draw clear conclusions.

Antithrombotic therapy in peripheral artery disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline focuses on antithrombotic drug therapies for primary and secondary prevention of cardiovascular disease as well as for the relief of lower-extremity symptoms and critical ischemia in persons with peripheral arterial disease (PAD).

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

The most important of our 20 recommendations are as follows. In patients aged ≥ 50 years with asymptomatic PAD or asymptomatic carotid stenosis, we suggest aspirin (75-100 mg/d) over no therapy (Grade 2B) for the primary prevention of cardiovascular events. For secondary prevention of cardiovascular disease in patients with symptomatic PAD (including patients before and after peripheral arterial bypass surgery or percutaneous transluminal angioplasty), we recommend long-term aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 1A). We recommend against the use of warfarin plus aspirin in patients with symptomatic PAD (Grade 1B). For patients undergoing peripheral artery percutaneous transluminal angioplasty with stenting, we suggest single rather than dual antiplatelet therapy (Grade 2C). For patients with refractory claudication despite exercise therapy and smoking cessation, we suggest addition of cilostazol (100 mg bid) to aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 2C). In patients with critical limb ischemia and rest pain unable to undergo revascularization, we suggest the use of prostanoids (Grade 2C). In patients with acute limb ischemia due to acute thrombosis or embolism, we recommend surgery over peripheral arterial thrombolysis (Grade 1B).

CONCLUSIONS

Recommendations continue to favor single antiplatelet therapy for primary and secondary prevention of cardiovascular events in most patients with asymptomatic PAD, symptomatic PAD, and asymptomatic carotid stenosis. Additional therapies for relief of limb symptoms should be considered only after exercise therapy, smoking cessation, and evaluation for peripheral artery revascularization.

[Peripheral arterial disease. Diagnosis and therapy according to current guidelines]

Guidelines conduce to establish consistent standards of therapy and contribute to the orientation and safeguard of the attending physician. Peripheral arterial disease (PAD) may be classified according to its stage as intermittent claudication, chronic critical limb ischemia or acute limb ischemia. Since these diseases are common and life-threatening, current guidelines are of major interest for the attending physician, not least because of forensic reasons. This overview describes the current principles of diagnosis and therapy as well as recent developments in peripheral endovascular intervention. Current national and international guidelines, particularly the Transatlantic Intersociety Consensus (TASC), were taken into account.

Thrombolysis for Acute Lower Limb Ischaemia—A Prospective, Randomised, Multicentre Study Comparing Two Strategies

OBJECTIVES

To test if initial high-dose, pulse-spray thrombolysis improves the early and late outcome of lower limb ischaemia as compared with low-dose infusion alone.

DESIGN

Prospective randomised multicentre study.

MATERIAL AND METHODS

Patients with acute and sub-acute (<30 days) lower limb ischaemia were randomised following angiography. Group 1 (n=58) received pulse-spray infusion of recombinant plasminogen activator (rt-PA, 15 mg/h) for 2h followed by low-dose infusion if needed. Group 2 (n=63) were only treated with low-dose infusion (0.5mg/h) of rt-PA for 48 h. Underlying lesions were corrected if required.

RESULTS

The study was stopped prematurely. Complications were equally frequent in both groups. More than 75% lysis was accomplished in 78 versus 67% of the patients (p=0.21). Primary endpoints (re-occlusion, incomplete lysis, life-threatening complication, amputation, or death) were reached in 24 versus 32% of the patients (p=0.35). Neither vascular patency nor clinical parameters differed during the first year, but re-interventions tended to be more frequent (p=0.040 at 1 month; p=0.090 at 1 year) and of a greater magnitude (p=0.028) in group 2.

CONCLUSIONS

There was no obvious advantage with initial high-dose thrombolysis, which may be a type-2 error. A reduction of major re-interventions was recorded.

Transhepatic fibrinolysis of mesenteric and portal vein thrombosis in a patient with ulcerative colitis: A case report

AIM: To present a case of acute mesenteric and portal vein thrombosis treated with thrombolytic therapy in a patient with ulcerative colitis in acute phase and to review the literature on thrombolytic therapy of mesenteric-portal system. Treatment of acute portal vein thrombosis has ranged from conservative treatment with thrombolysis and anticoagulation therapy to surgical treatment with thrombectomy and/or intestinal resection.

METHODS: We treated our patient with intraportal infusion of plasminogen activator and then heparin through a percutaneous transhepatic catheter.

RESULTS: Thrombus resolved despite premature interruption of the thrombolytic treatment for neurological complications, which subsequently resolved.

CONCLUSION: Conservative management with plasminogen activator, could be considered as a good treatment for patients with acute porto-mesenteric thrombosis.

Thrombolytic Therapies:The Current State of Affairs

Thrombotic occlusive diseases are manifested in several disorders that have significant morbidity and mortality, including acute myocardial infarction, pulmonary embolism, deep venous thrombosis, and cerebrovascular accidents. This review summarizes the recently published literature covering thrombolytic therapies in these diseases, with particular attention to comparisons between the fibrin-specific tissue plasminogen activators (alteplase, reteplase, and tenecteplase) and the nonfibrin-specific activators (streptokinase or urokinase plasminogen activator). These agents act to convert plasminogen to plasmin, which in turn cleaves fibrin as part of the lysis process. Fibrin-specific activators were anticipated to be more efficacious and safer than nonspecific agents in thrombolytic occlusive diseases because of their pathophysiologically restricted mechanism of action. However, the fibrin-specific activators also lyse physiological hemostatic plugs, which can result in costly adverse events. Efficacy of fibrin-specific tissue plasminogen activators has been shown to be generally equivalent, with similar mortality rates compared with nonspecific agents; however, fibrin-specific agents may be associated with an increased incidence of intracerebral hemorrhage and with increased costs. Therefore, it appears that given equivalent efficacy, nonfibrin-specific activators, such as streptokinase or urokinase, may be a safer choice in many thrombotic situations.

Safety of Thrombolytic Therapy with Urokinase or Recombinant Tissue Plasminogen Activator for Peripheral Arterial Occlusion:A Comprehensive Compilation of Published Work

PURPOSE

To report a comprehensive literature review focused on comparing the risk of complications with urokinase versus recombinant tissue plasminogen activator (rtPA) for thrombolytic treatment of peripheral arterial occlusions.

METHODS

The English-language literature between 1985 and 2002 was searched for studies that used tissue-derived urokinase or rtPA in the treatment of peripheral arterial occlusions. Forty-eight studies (22 urokinase, 22 rtPA, and 4 that included both treatments) were identified, encompassing 2226 urokinase-treated patients and 1927 rtPA-treated patients. The safety of each thrombolytic agent was assessed based on the incidence of major hemorrhage, intracerebral hemorrhage, major limb amputation, transfusions, and mortality.

RESULTS

The review revealed a wide range of study protocols, patient conditions, ages of occlusions, dosages/delivery methods of lytic agents, and criteria for reporting complications. The incidence of major hemorrhage varied widely, but the overall rate was lower among urokinase-treated patients (6.2%) than for patients treated with rtPA (8.4%, p=0.007). The overall incidence of intracerebral hemorrhage was also significantly lower for urokinase (0.4% versus 1.1% for rtPA, p=0.020). The major amputation rate was similar for both treatments (urokinase 7.9%, rtPA 7.2%), but the mortality rate was significantly lower for urokinase (3.0% versus 5.6% for rtPA, p<0.001). The need for transfusions was less frequent with urokinase (11.1% versus 16.1%, p=0.002).

CONCLUSIONS

These results from a large body of published literature suggest that urokinase may be associated with a lower incidence of complications than rtPA in the treatment of peripheral arterial occlusions.

Percutaneous infusion system for in situ thrombolysis in the abdominal aorta and iliac arteries

PURPOSE

To report successful treatment of an occluded aorta with a new percutaneous infusion system.

CASE REPORT

A 57-year-old man was admitted in severe pain with cyanosis and acrocyanotic pigmentation in the lower abdomen and limbs. The patient had symptoms of renal disease and severe oligoanuria. Ultrasound scanning detected no flow in the lower limbs, and angiography identified total thromboembolic occlusion of the aorta immediately below the origin of the renal arteries. A new Trellis percutaneous thrombolytic infusion system was used for controlled site-specific infusion and dispersion of streptokinase into the abdominal aorta and the iliofemoral arteries bilaterally with successful restoration of flow and no complications.

CONCLUSIONS

The Trellis system is effective for rapid lysis of thrombotic emboli using low doses of lytic agents. The unique design of the Trellis allowed complete aspiration of the residual thrombus, thus avoiding adverse effects.