Diagnostic and prognostic value of early MR Imaging vessel signs in hyperacute stroke patients imaged <3 hours and treated with recombinant tissue plasminogen activator

BACKGROUND AND PURPOSE

Analogous to the CT hyperattenuated vessel sign (HMCAS), MR imaging may show hypo- or hyperintense vessels in acute ischemic stroke (AIS) patients. We assessed the diagnostic and prognostic strength of early MR imaging vessel signs in AIS patients treated with intravenous thrombolysis (IVT) within 3 hours of the onset of symptoms.

METHODS

We studied AIS patients both treated with IVT and stroke MR imaged within 3 hours of the onset of symptoms and at 2 hours and 24 hours after treatment. We assessed the presence or absence of early vessel signs (hyperintense fluid-attenuated inversion recovery sign [FLAIR HVS]; gradient-echo susceptibility vessel sign [GRE SVS]) compared with a combined MR angiography/perfusion-weighted imaging reference and their strength for predicting clinical outcome (favorable vs. poor, independent vs. dependent, or dead, death), recanalization (by clot composition and flow), and hemorrhage in uni- and multivariate analysis.

RESULTS

Fifty-six patients (age range, 76 years +/- 13 years; median National Institutes of Health stroke scale score [NIHSSS], 11) met the inclusion criteria. Forty-four patients (78.6%) had a vessel occlusion at baseline; 22 of them (50%) recanalized. Nineteen patients (33.9%) suffered some form of intracranial hemorrhage (ICH), 24 patients (42.9%) had an independent outcome, 18 patients (32.1%) a favorable outcome, and 14 patients died. Compared with our combined reference for vessel status PWI/MRA, the sensitivities of CT HMCAS, FLAIR HVS, and GRE SVS were 40%, 66%, and 34%, respectively, and improved during the hours that followed. Localization was accurately reflected by FLAIR HVS but not by GRE SVS. Only NIHSSS and age were independent predictors for recanalization and all clinical outcomes in multiple logistic regression analysis.

CONCLUSION

Although early vessel signs can be helpful in the diagnosis of intravascular disease, they do not independently predict recanalization, ICH, or any of the three clinical outcomes in a multivariate logistic regression model. Thrombus composition as reflected by signal intensity characteristics on GRE and FLAIR does not predict the therapeutic effect of IVT.

Medical management of parapneumonic pleural disease

Considerable heterogeneity exists in the management of parapneumonic pleural disease. A randomized controlled trial (RCT) demonstrated the effectiveness of small-catheter drainage with fibrinolysis, but surgical devotees suggest this may only be applicable to "early" cases. We examined evidence-based medical management in "all-comers." We performed a retrospective database analysis of the management of all children with complex pleural effusion admitted to the John Radcliffe Hospital over the 7-year period 1996-2003. One hundred and ten children were admitted. Ten were excluded as they were part of a multicenter RCT and had received intrapleural saline instead of urokinase. Of the remaining 100, 51 were female and 49 male. Median age on admission was 5.8 years (range, 0.3-16.5). Symptoms preadmission averaged 11 days, with December the most common month for presentation. Ninety-six underwent chest ultrasound, confirming an effusion in all, described as loculated/septated (68) or echogenic (11). In 17 cases, no specific comment was made regarding the nature of the fluid seen on ultrasound. Ninety-five had subsequent chest tube drainage and then received intrapleural fibrinolysis with urokinase. An etiological organism was identified in 21 cases (21%) (Streptococcus pneumoniae in 10, group A Streptococcus in 5, Staphylococcus aureus in 4, Haemophilus influenzae in 1, and coliform in 1). In a further 9 cases (9%), Gram-positive organisms were seen on pleural fluid microscopy, but did not grow on culture. Two (2%) required surgery due to the persistence of symptoms and an inadequate response to medical management. Median duration of admission was 7 days (range, 2-21 days); median duration of stay from intervention was 5 days (range, 2-19 days). At median follow-up of 8 weeks (range, 3-20 weeks), all children were symptom-free, with minimal pleural thickening on chest X-ray. In conclusion, antibiotic therapy with chest drain insertion and intrapleural urokinase is effective in treating complex parapneumonic effusion and is associated with a good long-term outcome.

Combined IV and intra-arterial thrombolysis for acute ischemic stroke

Combined IV and intra-arterial (IA) thrombolysis for acute ischemic stroke may offer advantages over either technique alone. Sixty-two nonrandomized patients with NIH Stroke Scale scores of > or =10 who met standard criteria for IV thrombolysis were treated with an IV/IA approach. Three-month modified Rankin Scale scores were 0 to 2 for 50% of patients, mortality was 18%, and symptomatic intracerebral hemorrhage occurred in 8%. IV/IA thrombolysis appeared safe and effective in this group.

Angiography and revascularization in patients with heart failure following fibrinolytic therapy for ST-elevation acute myocardial infarction

We evaluated the use of coronary angiography and clinical outcomes among patients who had heart failure and were enrolled in the Intravenous Novel Plasminogen Activator (NPA) for the Treatment of Infarcting Myocardium Early study, a large international trial of fibrinolytic therapy in ST-elevation myocardial infarction.

Reversal of Locked-In Syndrome With Anticoagulation, Induced Hypertension, and Intravenous t-PA

INTRODUCTION

Widespread use of intravenous tissue plasminogen activator (t-PA) for acute ischemic stroke is limited by multiple contraindications to its use.

CASE REPORT

This article describes a patient with stuttering symptoms of pontine ischemia caused by vertebrobasilar dissection who suddenly deteriorated into a locked-in state 32 hours after symptom onset. The quadriparesis was successfully reversed within 3 hours of onset with the combination of pharmacologically induced hypertension, anticoagulation, and intravenous t-PA.

DISCUSSION

Even in the face of numerous contraindications (including hypertension, anticoagulation, and treatment beyond 3 hours of symptom onset), intravenous t-PA can be used successfully in carefully selected cases.

Analysis of combined treatment of embolic stroke in rat with r-tPA and a GPIIb/IIIa inhibitor

Suppression of platelet activation improves the efficacy of thrombolytic therapy for stroke. Thus, combination treatment with recombinant tissue plasminogen activator (r-tPA) and 7E3 F(ab')2, a GPIIb/IIIa inhibitor that binds the platelet to fibrin, may improve the efficacy of thrombolytic therapy in embolic stroke. Magnetic resonance imaging (MRI) was used to monitor treatment response in rats subjected to embolic middle cerebral artery (MCA) occlusion (MCAo). Animals were randomized into treated (n=12) and control (n=10) groups and received intravenous combination therapy or saline, respectively, 4 hours after MCAo. Magnetic resonance imaging (MRI) measurements performed 1 hour after MCAo showed no difference between groups. However, an increased incidence (50%) of MCA recanalization was found in the treated group at 24 hours compared with 20% in the control group. The area of low cerebral blood flow at 24 and 48 hours was significantly smaller in the combination treatment group, and the lesion size, as indicated from the T2 and T1 maps, differed significantly between groups. Fluorescence microscopy measurements of cerebral microvessels perfused with fluorescein isothiocyanate-dextran and measurements of infarct volume revealed that the combination treatment significantly increased microvascular patency and reduced infarct volume, respectively, compared with the control rats. The efficacy of combination treatment 4 hours after ischemia is reflected by MRI indices of tissue perfusion, MCA recanalization, and reduction of lesion volume. The treatment also reduced secondary microvascular perfusion deficits.

Long-term treatment of plastic bronchitis with aerosolized tissue plasminogen activator in a Fontan patient

OBJECTIVE

To report the successful treatment of plastic bronchitis with aerosolized tissue plasminogen activator.

DESIGN

Case report.

PATIENTS

A 4-yr-old boy with congenital heart disease, who developed plastic bronchitis 33 months after a Fontan operation

INTERVENTIONS

Long-term treatment with aerosolized tissue plasminogen activator.

MEASUREMENTS AND MAIN RESULTS

We describe the case of a boy who developed recurrent episodes of life-threatening airway obstruction secondary to plastic bronchitis. Following the failure of multiple therapeutic interventions, his condition improved significantly with aerosolized tissue plasminogen activator. Several attempts to wean him off this treatment resulted in clinical deterioration. He has remained on long-term aerosolized tissue plasminogen activator.

CONCLUSION

Treatment of plastic bronchitis with aerosolized tissue plasminogen activator may benefit patients in whom other therapies have failed.

Acute Myocardial Infarction in a Patient With Essential Thrombocythemia Successful Treatment With Percutaneous Transluminal Coronary Recanalization

A 65-year-old woman with essential thrombocythemia (ET) was admitted to hospital where she was diagnosed as acute myocardial infarction (AMI). Because of abundant thrombus of right coronary arteries, percutaneous transluminal coronary recanalization by administration of urokinase was selected as the reperfusion therapy, resulting in successful revascularization with Thrombolysis in Myocardial Infarction grade III coronary flow. The maximum creatine kinase reached 507 IU/L, and left ventriculography performed at 1 month after initiation of both anticoagulant and antiplatelet therapies revealed reduced motion in the inferior wall with an ejection fraction of 57%. Despite good recovery of left ventricular function, bleeding complications, such as epistaxis or ecchymoma, which did not require blood transfusion, occurred during the clinical course. Because ET causes not only thrombus formation but also bleeding tendency, it is very important to carefully follow-up any clotting abnormality in AMI patients with ET.

Pulmonary microthrombi during left ventricular assist device implantation

Critically ill heart failure patients undergoing left ventricular assist device implantation have alterations in their coagulation profiles; as a result, hemorrhagic complications during the postoperative period are the most common and serious problems during device support of these patients. The use of aprotinin therapy is generally accepted for reducing bleeding after coronary artery bypass grafting procedures, heart transplantation, and insertion of a left ventricular assist device. We describe the case of a patient who had a suprasystemic increase in pulmonary artery pressure, caused by thromboembolic occlusion of the pulmonary arterioles after urgent implantation of a left ventricular assist device. The complications developed after the patient was weaned from cardiopulmonary bypass and heparinization was reversed with protamine. Although the thrombosis was successfully reversed with intraoperative administration of tissue plasminogen activator directly to the pulmonary artery, the patient died of massive hemorrhage 6 hours later. To our knowledge, the direct application of tissue plasminogen activator into the pulmonary artery in such a catastrophic situation has not been used elsewhere.

Comparison of intravenous and intra-arterial urokinase thrombolysis for acute ischaemic stroke

Intravenous fibrinolysis (IVF) with rt-PA (alteplase) provides significant benefits in acute ischaemic stroke when it is given within the first three hours following stroke onset. Intra-arterial fibrinolysis (IAF) with pro-urokinase in PROACT II study provides quite the same benefit in the first 6 hours. IVF and IAF have never been compared. To compare the efficacy and safety of IVF and IAF with urokinase given within the first 6 hours of acute ischaemic stroke. Patients fulfilling the selection criteria were randomly assigned to receive urokinase 900,000 units via intravenous or intra-arterial routes. This randomised monocentre study was done between December 1995 and August 1997. The primary outcome was defined as the number of patients with a modified Rankin score of 2 or less. Secondary outcomes included mortality, frequency of symptomatic intracranial haemorrhage (SIH), neurological and functional scores. Fourteen patients were given IVF and 13 IAF. The study was terminated by the National Health Authorities when 27 patients had been included because of the mortality rate. Seven patients (26%) died, 4 in the IV group (oedematous infarct in 3 and recurrence in 1), 3 in the IA group (SIH in 2, and oedematous infarct in 1). Patients given IVF were treated significantly earlier (4:16 h vs 5:24 h; p=.007). Although IA patients showed greater and earlier improvement there was no significant difference in primary and secondary outcomes. Because of premature termination, the trial was too small to provide any reliable and conclusive results. Intra-arterial fibrinolysis began significantly later than IV fibrinolysis but it gave non-significantly better results in this prematurely terminated study.

Intra-Arterial Thrombolysis of a Distal Internal Carotid Artery Occlusion in an Adolescent

INTRODUCTION

This article describes the first reported case of an adolescent being treated with intra-arterial urokinase for a distal internal carotid artery occlusion.

METHODS

A 15-year-old male presenting with an acute ischemic stroke caused by a distal internal carotid artery occlusion was treated with intra-arterial urokinase at 5 hours and 45 minutes after symptom onset.

RESULTS

The artery completely recanalized, and the patient improved significantly from an admission National Institutes of Health Stroke Scale (NIHSS) score of 28 to a NIHSS score of 8 at a 2.5-month follow-up, despite an asymptomatic intraparenchymal hemorrhage.

CONCLUSION

This article reviews the only two reported cases of intravenous thrombolysis and three cases of intra-arterial thrombolysis in children with ischemic stroke and suggests that thrombolytic therapy should be considered a treatment option in selected pediatric patients with stroke, especially in adolescents who are generally treated as young adults.

The Desmoteplase in Acute Ischemic Stroke Trial (DIAS): a phase II MRI-based 9-hour window acute stroke thrombolysis trial with intravenous desmoteplase

BACKGROUND AND PURPOSE

Most acute ischemic stroke patients arrive after the 3-hour time window for recombinant tissue plasminogen activator (rtPA) administration. The Desmoteplase In Acute Ischemic Stroke trial (DIAS) was a dose-finding randomized trial designed to evaluate the safety and efficacy of intravenous desmoteplase, a highly fibrin-specific and nonneurotoxic thrombolytic agent, administered within 3 to 9 hours of ischemic stroke onset in patients with perfusion/diffusion mismatch on MRI.

METHODS

DIAS was a placebo-controlled, double-blind, randomized, dose-finding phase II trial. Patients with National Institute of Health Stroke Scale (NIHSS) scores of 4 to 20 and MRI evidence of perfusion/diffusion mismatch were eligible. Of 104 patients, the first 47 (referred to as Part 1) were randomized to fixed doses of desmoteplase (25 mg, 37.5 mg, or 50 mg) or placebo. Because of an excessive rate of symptomatic intracranial hemorrhage (sICH), lower weight-adjusted doses escalating through 62.5 microg/kg, 90 microg/kg, and 125 microg/kg were subsequently investigated in 57 patients (referred to as Part 2). The safety endpoint was the rate of sICH. Efficacy endpoints were the rate of reperfusion on MRI after 4 to 8 hours and clinical outcome as assessed by NIHSS, modified Rankin scale, and Barthel Index at 90 days.

RESULTS

Part 1 was terminated prematurely because of high rates of sICH with desmoteplase (26.7%). In Part 2, the sICH rate was 2.2%. No sICH occurred with placebo in either part. Reperfusion rates up to 71.4% (P=0.0012) were observed with desmoteplase (125 microg/kg) compared with 19.2% with placebo. Favorable 90-day clinical outcome was found in 22.2% of placebo-treated patients and between 13.3% (62.5 microg/kg; P=0.757) and 60.0% (125 microg/kg; P=0.0090) of desmoteplase-treated patients. Early reperfusion correlated favorably with clinical outcome (P=0.0028). Favorable outcome occurred in 52.5% of patients experiencing reperfusion versus 24.6% of patients without reperfusion.

CONCLUSIONS

Intravenous desmoteplase administered 3 to 9 hours after acute ischemic stroke in patients selected with perfusion/diffusion mismatch is associated with a higher rate of reperfusion and better clinical outcome compared with placebo. The sICH rate with desmoteplase was low, using doses up to 125 microg/kg.

Hypothenar-Hammer-Syndrom als Ursache einer schweren digitalen Ischämie

HISTORY AND CLINICAL FINDINGS

A 69-year-old amateur carpenter complained of a sudden stabbing pain and a white discoloration of D4 and D5 of the right hand while shoveling snow. On admission in our clinic twelve days later, clinical inspection showed a gangrene of the distal bone of D5 and proximal garland-shaped radial and ulnar subcutaneous haemorrhage and already ischemic contracture. D4 showed pale livid colour.

INVESTIGATIONS

According to the results of an arteriography acral pulse oscillography revealed a occlusion of the digital arteries. Duplex sonography showed a thrombotic occluded aneurysm of the right ulnar artery over the hypothenar area.

DIAGNOSIS

Hypothenar hammer syndrome with a thrombotic occlusion of an aneurysm of the distal ulnar artery and multiple thromboembolic occlusions of the digital arteries of D4 and D5 of the right hand.

TREATMENT AND COURSE

After initial therapy with Iloprost, treatment of pain and local treatment, an intraarterial locoregional lysis therapy with urokinase was performed. Acral blood circulation improved significantly and the patient was completely painless after treatment.

CONCLUSION

In case of an acute onset of unilateral digital ischemia hypothenar hammer syndrome should be considered. Regional thrombolysis can be performed in case of severe digital ischemia.

Combined regional thrombolysis and surgical thrombectomy for treatment of iliofemoral vein thrombosis

OBJECTIVE

In at least half of patients with iliofemoral deep vein thrombosis post-thrombotic syndrome develops when only anticoagulant therapy is given. We combined thrombolysis, applied under ischemic conditions,with surgical thrombectomy to restore patency and valve function. The technique and the short-term and long-term results in 2 patient series are reported.

METHODS

A catheter was inserted into a foot vein of the thrombosed leg, and the limb was excluded from the circulation with a pneumatic cuff placed on the thigh with the patient under general anesthesia. Urokinase (0.5 million-3 million IU) and heparin were infused and allowed to act for 30 minutes while the pelvic axis was cleared with a Fogarty catheter through an inguinal venotomy. The external iliac vein was then clamped and the cuff removed. Thrombi that detached from the wall were flushed out with reactive hyperemia and squeezed out with manual leg compression. The blood was retrieved, washed, and transfused back into the patient. Various additional procedures were performed to secure outflow. Two patient series are reported: 1 with 12 consecutive patients and 1 with 21 patients who were successfully treated 6 to 10 years previously. Follow-up data were obtained for all patients after 1 year and for 18 of 21 patients after 6 to 10 years. Patency and valve function were assessed with duplex scanning or venography. Studies of blood coagulation and the kinetics of urokinase were performed in 5 additional patients.

RESULTS

Vein patency and valve function were restored in all consecutive patients. At 1 year none of the 33 patients had had recurrence, and none showed clinical signs of post-thrombotic syndrome. At 6 to 10 years 3 of 18 patients had experienced another venous thromboembolism, but none in the treated leg. Sixteen legs were asymptomatic without compression therapy, and 2 had venous claudication. Coagulation studies showed a trace concentration of urokinase and a mild decrease in fibrinogen in the systemic circulation. The concentration of urokinase in blood collected from the treated leg was only 1% of that infused.

CONCLUSION

Regional thrombolysis combined with surgical thrombectomy is relatively easy to perform and seems safe. Vein patency and valve function were restored, and post-thrombotic syndrome was prevented. Additional procedures to overcome pelvic vein obstructions were required in 11 of 33 patients (33%). The procedure should be tested against standard anticoagulation therapy in patients with acute iliofemoral thrombosis.

Endovascular management of iliofemoral deep venous thrombosis due to iliac vein compression syndrome in patients with protein C and/or S deficiency

The purpose of this study was to evaluate the early outcome of endovascular management in patients with iliofemoral deep venous thrombosis (DVT) due to iliac vein compression syndrome (IVCS) and protein C and/or S deficiency. Between September 2000 and January 2003, catheter-directed thrombolysis was performed in 11 patients with a diagnosis of acute iliofemoral DVT: 7 with protein C and/or S deficiency and 4 without protein C and/or S deficiency. After thrombolysis, the diagnosis of IVCS was confirmed in 6 patients: 4 with protein C and/or S deficiency and 2 without protein C and/or S deficiency. Further intervention consisted of angioplasty and stent placement was performed. Four patients with IVCS and protein C and/or S deficiency were included in this study. The immediate technical and clinical success rates were 100% in all 4 patients. There were no complications or clinically detectable pulmonary emboli. This initial experience suggests that endovascular management of iliofemoral DVT due to IVCS in patients with protein C and/or S deficiency is safe and effective.

Ultrasound Identification and Lysis of Clots

Poor recovery after systemic tissue plasminogen activator (tPA) therapy could result from the initial severity of ischemic insult and slow and incomplete thrombolysis. Persisting arterial occlusions can be identified at bedside using portable diagnostic ultrasound by detecting residual flow signals around the thrombus (thrombolysis in brain ischemia [TIBI] flow grades). A narrow pulsed ultrasound beam can be steadily aimed at the thrombus/residual flow interface, exposing more thrombus surface and structures to tPA, and tPA activity can be enhanced with 2 MHz transcranial Doppler (TCD). A randomized, multicenter, clinical trial called CLOTBUST (Combined Lysis of Thrombus in Brain ischemia using transcranial Ultrasound and Systemic tPA) trial showed a 49% rate of complete recanalization or dramatic clinical recovery from stroke within 2 hours after tPA bolus when tPA infusion was continuously monitored with TCD, compared with 30% among patients who received tPA without ultrasound monitoring (P=0.03, number needed to treat, 5). Early complete recanalization was sustained at 2 hours by 38% of monitored patients compared with 12.7% controls. The CLOTBUST Trial showed a trend toward sustaining complete recovery at 3 months (41.5% versus 28%, modified Rankin Scale scores 0 to 1), subject for a pivotal phase III trial. Ultrasound is an inexpensive, noninvasive, real-time monitoring tool to identify nonresponders to systemic tPA and select patients with persisting occlusions for intraarterial interventions. Early brain perfusion augmentation, complete recanalization, and dramatic clinical recovery are feasible goals for ultrasound-enhanced thrombolysis.

Urokinase for restoring patency of malfunctioning or blocked central venous catheters in children with hemato-oncological diseases

GOALS OF WORK

To evaluate differences in success rate between two dosages of intraluminal urokinase (IL-UK) for treatment of withdraw occlusion in central venous catheters (CVC) and to confirm the efficacy of a salvage protocol with low-dose systemic urokinase (S-UK) in case of failure of IL-UK or of complete catheter obstruction.

PATIENTS AND METHODS

All malfunctioning or occluded partially implanted indwelling catheters inserted in a 29-month period in children with cancer at two tertiary care centers (Genoa and Turin) in Italy were eligible for this study. In cases of withdraw occlusion, IL-UK was used as first-line treatment with different schedules of administration in the two centers: a 5,000 IU/ml dose was used in Genoa and a 25,000 IU/ml dose in Turin (Protocol A). In case of failure of the front-line protocol or in case of complete CVC occlusion, S-UK at 1,000 IU/kg per hour for 3 h was used as a salvage protocol in both centers (Protocol B).

MAIN RESULTS

There were 81 episodes of malfunction and three of occlusion recorded in 68 CVCs. Protocol A was successful in 75 (92.5%) of the malfunction episodes. In particular, the dose of 5,000 IU of IL-UK was successful in 42 (89%) CVCs while the 25,000 IU dose resolved 33 (97%) of the episodes (not significant). The six patients with CVC refractory to IL-UK and the three subjects with complete CVC occlusion were treated with S-UK. Patency was obtained in seven cases (78%); the remaining two catheters had to be removed.

CONCLUSIONS

We found that 5,000 IU of IL-UK were as effective as 25,000 IU to resolve withdrawal occlusion in partially implanted CVCs and that systemic treatment with urokinase may rescue a significant proportion of CVCs refractory to IL-UK or that are apparently completely occluded.

Prophylactic urokinase in the management of long-term venous access devices in children: a Children's Oncology Group study

PURPOSE

Infection and thrombosis are serious complications of long-term vascular access devices in children undergoing chemotherapy. Since routine fibrinolytic therapy may decrease these complications, the purpose of this study was to compare the efficacy of an every-2-week administration of urokinase with standard heparin flushes in reducing the incidence of device-related infections and occlusions.

MATERIALS AND METHODS

This study was a prospective, randomized phase III multicenter trial conducted by the Children's Cancer Group, in which patients with implantable ports or tunneled catheters received either urokinase or heparin every 2 weeks for 12 months. Study end points were time to first occlusion or time to first device-related infection.

RESULTS

Five hundred seventy-seven patients from 29 institutions were enrolled, of whom 51% had external catheters and 49% had ports. Urokinase administration resulted in fewer occlusive events than heparin (23% v 31%; P =.02), a longer time to first occlusive event (log-rank analysis, P =.006), and a 1.6-fold difference in the rate of occlusive events (Poisson regression, P =.003). Similar results were noted when comparing ports and tunneled catheters. The urokinase group also had a 1.4-fold difference in the rate of infection (Poisson regression, P =.05) and longer time to first infection (log-rank, P =.07), but the difference was significant only in tunneled catheters.

CONCLUSION

Urokinase administration every 2 weeks significantly affects the rate of occlusive events in ports and tunneled catheters and of infectious events in external catheters compared with heparin administration.

Recanalization by mechanical embolus disruption during intra-arterial thrombolysis in the carotid territory

BACKGROUND AND PURPOSE

Mechanical disruption of a clot with a microcatheter and a guidewire has not been detailed in conjunction with intra-arterial thrombolysis in patients with acute ischemic stroke. The purpose of this study was to evaluate the efficacy of mechanical disruption of an embolus in the carotid artery distribution.

METHODS

We analyzed clinical and radiologic findings and functional outcomes 3 months after thrombolysis with mechanical disruption. Outcomes were classified as good for modified Rankin scale (mRS) scores of 0-2, moderate for mRS scores of 3, and poor for death and mRS scores of 4 or 5.

RESULTS

Twenty-three consecutive patients with severe hemispheric symptoms were treated with several methods of mechanical embolus disruption during the intra-arterial administration of urokinase. Twelve patients had occlusions of the proximal middle cerebral artery (MCA), and 11 had occlusions of the distal internal carotid artery (ICA). Recanalization was observed in all patients with MCA occlusions and in 10 (91%) with ICA occlusions. Outcomes were good in nine patients (75%) with MCA occlusions and in four (36.4%) with ICA occlusions. Early management of vessel perforation, caused by a microguidewire tip in two patients, resulted in early hemostasis. Neither patient had a major deficit attributable to the complication.

CONCLUSION

A high incidence of recanalization and clinical improvement can be observed in patients with occlusions of not only the proximal MCA but also the distal ICA. This method might be an effective additional option to intra-arterial thrombolysis for acute distal ICA and proximal MCA occlusions.

Distributed intraclot thrombolysis: mechanism of accelerated thrombolysis with encapsulated plasminogen activators

BACKGROUND

The delivery of encapsulated plasminogen activators has demonstrated enhanced thrombolysis in vivo in several models. The mechanism of such improvement has not previously been established.

OBJECTIVES

We explored in vitro the mechanism by which microencapsulation of streptokinase in polymeric microparticles accelerates clot digestion and reduces reperfusion times by as much as an order of magnitude in vivo.

METHODS

The efficacy of microencapsulated streptokinase (MESK) was directly compared with identical dosages of unencapsulated streptokinase (FREE SK) at three initial pressure drops using clots formed of plasma or whole blood in 0.2-cm inner diameter glass capillary tubes.

RESULTS

MESK demonstrated accelerated flow restoration compared with FREE SK for each condition in plasma (23.8 +/- 4.5% faster) and whole blood clots (17.2 +/- 9.2% faster). Images collected by light microscopy show sites of thrombolysis internal to the clot only with MESK while the spatial distribution of fluorescently labeled streptokinase by confocal microscopy confirms greater penetration of the encapsulated agent compared with unencapsulated streptokinase. Digestion thus proceeds in three dimensions rather than restricted to a two-dimensional lysis front.

CONCLUSIONS

The improved clot penetration with MESK establishes enhanced transport with encapsulation and the concept of distributed intraclot thrombolysis as a basis for the accelerated dissolution observed with encapsulated plasminogen activators in vivo.

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.

[Effectiveness and safety of intraventricular fibrinolysis in secondary intraventricular hemorrhages (a prospective, randomized study)]

BACKGROUND AND PURPOSE

Intraventricular clot secondary to brain hemorrhage has still one of the worst prognosis among all stroke subtypes, regardless of conservative therapy or surgical interventions. The rapid clot resolution with thrombolytic agents could improve the outcome by restoring the impaired cerebrospinal fluid circulation, for this reason, the authors examined the safety and efficacy of Urokinase therapy in a randomized, controlled study.

METHODS

They enrolled 27 patients with severe intraventricular hemorrhage between 1998 and 2002. All patients had supratentorial intracerebral hemorrhage caused by hypertension, with IVH, moreover clinically worsening course due to the obstructive hydrocephalus confirmed by CT. Eleven persons were treated with ventriculostomy alone and 16 received adjunctive intraventricular urokinase. The authors examined the early, 30-day and 1-year mortality, furthermore the neurological (Scandinavian Stroke Scale) and functional outcome (Barthel Scale). The mean age was 60 +/- 9.5. The initial Scandinavian Stroke Scale was 7.51 +/- 8.64, Glasgow Coma Scale was 6.85 +/- 2.52, intracerebral hemorrhage volume was 22.44 +/- 18.14 ml.

RESULTS

The 1 year survival rate was significant higher in the urokinase treated group (p = 0.014), This tendency in the mortality (31.3% vs. 54.5%) and in the neurological/functional condition (SSS, p = 0.078/Barthel, p = 0.119) at 30th day have been also documented. No hemorrhagic complications due to urokinase were observed. Two meningitis (7.4%) and two intraparenchymal hemorrhages (7.4%) related to drain insertion were detected (p = 0.009). The probability of pulmonary infection was roughly two times higher in the group without clot lysis (RR = 1.870; 95% CI: 1.004-3.482).

CONCLUSIONS

In the authors experience, urokinase treatment reveals to be safe in the intraventricular clot lysis. This therapy allows earlier mobilization and rehabilitation, and decreases the number of infections, which are favorable to the long-term survival rate.

Predictors of Hyperacute Clinical Worsening in Ischemic Stroke Patients Receiving Thrombolytic Therapy

BACKGROUND AND PURPOSE

Although long-term outcome determinants in acute ischemic stroke (AIS) patients have been defined, less is known about those predicting hyperacute worsening after thrombolytic therapy (TT). We investigated predictors of short-term clinical worsening (National Institutes of Health Stroke Scale [NIHSS] change > or =4 within 24 hours of admission).

METHODS

We studied 201 AIS patients who received TT within 6 hours of symptom onset. We determined baseline demographics, comorbidities, NIHSS at baseline and at 24 hours after TT, head computed tomography scan before and within 24 hours after TT, and angiographic recanalization in patients treated with intra-arterial (IA) thrombolysis. Significance of relationships was evaluated by t test or Wilcoxon signed rank sum test. Logistic regression model (LRM) was fitted to determine independence of significant variables.

RESULTS

Of 201 patients, 13% worsened, 39% improved, and 48% remained unchanged 24 hours after TT. Most patients (72%) received IA thrombolysis. Patients who deteriorated, compared with those who improved, were more likely to have complicating intracranial hemorrhage (ICH; P<0.001), absent recanalization (P=0.026), and higher blood glucose (BG; P=0.049). Hyperglycemia (>150 mg/dL) was greater in patients who worsened even in presence of recanalization (P=0.004, odds ratio [OR] 6.47). LRM showed that adjusted OR for increased risk of bad outcome and mortality for an increase of BG by 50 mg/dL is 1.56 and 1.38, respectively.

CONCLUSIONS

Hyperglycemia and ICH are independent predictors of hyperacute worsening in AIS patients receiving TT. Although recanalization is the purpose of IA thrombolysis, its impact on clinical improvement may not be apparent without strict BG control.

Rupture of a thoracic aortic aneurysm: a rare adverse reaction following systemic tissue plasminogen activator infusion

We present a patient with rupture of a thoracic aortic aneurysm occurring after systemic infusion of tissue plasminogen activator for the treatment of acute ischemic stroke, which was successfully treated with the placement of an endovascular stent-graft.

Successful thrombolysis after pulmonary embolectomy for persistent massive postoperative pulmonary embolism

Massive postoperative pulmonary embolism (PE) is associated with a poor prognosis in patients presenting with haemodynamic instability. Since recent surgery is a commonly accepted contraindication for thrombolytic therapy, pulmonary embolectomy is an appropriate therapeutic approach in these patients. If life-threatening symptoms of PE persist after pulmonary embolectomy, however, very few other therapeutic options are available. We report the successful use of locally administered low-dose thrombolysis 2 days after pulmonary embolectomy in a patient with postoperative PE and persistent severe hypoxaemia and pulmonary hypertension. During and after thrombolysis, no bleeding complications occurred. We conclude that low-dose thrombolysis for PE may be considered even in patients who have recently undergone major thoracic and abdominal surgery if embolectomy and continued intravenous heparin have failed to be successful and life-threatening symptoms of PE persist.

Alteplase for treatment of occluded peripherally inserted central catheters: safety and efficacy in 240 patients

PURPOSE

Peripherally inserted central catheters (PICCs) have dramatically improved intravenous therapy, but thrombotic occlusion remains a common problem. Despite the popularity of PICCs, there are few prospective data on the use of fibrinolytic agents to salvage these particular devices. The purpose of this study was to evaluate the efficacy and safety of alteplase treatment.

MATERIALS AND METHODS

A subgroup analysis was performed from a phase IIIB prospective, multicenter trial of 995 patients evaluating the use of alteplase to restore function in occluded venous catheters. Two hundred forty patients (126 men; mean age, 53.5 years; range, 2-90 y) with occluded single-lumen (n = 104) or double-lumen (n = 136) PICCs were identified and constitute the study population. Dysfunction was defined as the inability to withdraw 3 mL of blood. Alteplase (2 mg/2 mL) was instilled into the dysfunctional lumen and assessed at 30 and 120 minutes. If the lumen remained occluded, a second alteplase dose was instilled and assessed at 30 and 120 minutes. Patency was defined as the ability to withdraw 3 mL blood and infuse 5 mL of saline solution. The primary efficacy endpoint was the cumulative restored patency rate after a maximum of two doses of alteplase. The primary safety endpoint was the incidence of intracranial hemorrhage within 5 days of treatment. Serious adverse events were recorded for 30 days after treatment.

RESULTS

The primary efficacy endpoint was 92.9% (95% CI: 88.8%, 95.8%). Cumulative efficacy 30 and 120 minutes after first and second doses were 59.4%, 81.1%, 89.1%, and 92.9%, respectively. The primary safety endpoint was 0.0%. One major hemorrhage was reported: a patient with acute flare of ulcerative colitis experienced hematochezia 3 days after treatment. One serious adverse event (fever) was attributed to study drug.

CONCLUSIONS

Treatment with use of a maximum of two doses of alteplase is safe and effective in restoring function to occluded PICCs.

[Plasminogen activator of urokinase-type: mechanisms of involvement in vessel remodeling and angiogenesis, gene therapy approaches to ischemia]

The review summarizes data obtained by the authors and other laboratories concerning the role of urokinase plasminogen activator in vessel remodeling and angiogenesis. The data have shown that urokinase is involved in unfavorable vascular remodeling during the development of restenosis, atherosclerosis and also in the regulation of angiogenesis. Urokinase is a promising target for therapeutic interventions aimed at restenosis prevention. Urokinase gene therapy may be a perspective strategy for the treatment of tissue ischemia.

Construction and characterization of a recombinant plasminogen activator composed of an anti-fibrin single-chain antibody and low-molecular-weight urokinase

BACKGROUND

Targeting of plasminogen activators to the fibrin component of a thrombus by antibodies directed against human fibrin can enhance their thrombolytic potency and clot specificity.

OBJECTIVES

To overcome the disadvantages of chemical conjugation, we investigated whether the recombinant fusion of a single-chain antibody and a plasminogen activator results in an active bifunctional molecule that might be useful as a therapeutic agent.

METHODS

The cDNA of low-molecular-weight single-chain urokinase-type plasminogen activator, comprising amino acids Leu144-Leu411 (scuPA(LMW)), was cloned from human endothelial cells and fused to a single-chain antibody specific for the 7 N-terminal amino acids (beta(15-22)) in the beta-chain of human fibrin (scFv(59D8)). The fusion protein was purified using affinity chromatography with the beta(15-22)-peptide of human fibrin.

RESULTS

Purified scFv(59D8)-scuPA(LMW) migrated as a 60-kDa band, which is consistent with a molecule composed of one scFv(59D8) and one scuPA(LMW) moiety. Both functions of the fusion molecule, fibrin-specific binding and plasminogen activation, were fully preserved. In human plasma clots, thrombolysis by scFv(59D8)-scuPA(LMW) is significantly faster and more potent compared with the clinically used urokinase.

CONCLUSIONS

ScFv(59D8)-scuPA(LMW) constitutes a new recombinant chimeric plasminogen activator with a significantly enhanced thrombolytic potency and relative fibrin selectivity, that can be produced with modern methods at low cost, large quantities and reproducible activity in Escherichia coli.

[Thrombolysis and stent implantation in a child with an acute occlusion of the modified Blalock-Taussig shunt--a case report]

A case of a 5-year-old boy with complex heart disease and acute occlusion of modified Blalock-Taussig shunt is presented. The patient was treated with balloon angioplasty and local infusion of recombinant tissue plasminogen activator without persistent good effect. He was successful treated with the implantation of two coronary stents into the occluded shunt.

Tissue plasminogen activator levels after single intracisternal injection in patients with subarachnoid hemorrhage

Tissue plasminogen activator (tPA) levels were investigated in the cisternal fluid of patients with subarachnoid hemorrhage treated with single intracisternal injection of recombinant tPA during radical surgery for ruptured aneurysms. Seven patients received different doses of tPA: two of 400 microg/ml, three of 500 microg/ml, one of 700 microg/ml, and one of 800 microg/ml in a total amount of 20 ml distilled water at pH 7. Cerebrospinal fluid samples were taken directly from the cisternal fluid at 15-minute incubation after injection, immediately after irrigation during surgery, and by lumbar tap 2 days after surgery. Cisternal tPA levels decreased to about 60% of the mean injected doses after 15-minute incubation. Simple linear regression analysis showed these tPA levels after incubation correlated with the initial doses. After copious irrigation with Ringer solution at pH 8, tPA levels decreased rapidly without correlation with the initial doses. After spinal drainage for 2 days, tPA levels further decreased by an order of 10(-4) to 10(-6) from the initial dose. These values were still greater than normal controls. The final values of tPA levels were not related to the initial dose. None of the patients suffered from systemic or wound complications. Cisternal tPA injection with increased doses and irrigation may be beneficial for the selective rapid removal of blood clots with controllable safety.

[Study on the reperfusion rate of acute myocardial infarction affected by inspiring nitric oxide and resolving thrombus intravenously before admission]

OBJECTIVE

To observe the reperfusion rate of acute myocardial infarction (AMI) affected by inspiring nitric oxide (NO) and resolving thrombus through veins.

METHODS

Sixty cases with AMI were randomly divided into test group (n=30) and control groups (n=30). Patients in test group were cured with NO (20+/-1)mg/L inspiration for 30 minutes at once before admission and urokinase (150x10(4) U) adding 0.9% sodium chloride intravenously injected within 30 minutes, while patients in control were treated with urokinase as the same method of the test group.

RESULTS

The reperfusion and non-reperfusion patients were 25 and 5 cases in test group, and they were 19 and 11 cases in control group. The reperfusion rate of AMI in test group was significantly higher than that in control group 83.3% vs. 63.3% (P<0.05). No peak periods of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) appeared in test group, and the difference was significant compared to the control group (P<0.05).

CONCLUSION

NO inspiration before urokinase is an effective method to treat AMI and advance the reperfusion rate.

Hängt das Ergebnis einer Thrombolyse mit rekombinantem Gewebe-Plasminogenaktivator (rt-PA) beim Kaninchen vom Erythrozyten- und Fibringehalt eines Thrombus ab?

PURPOSE

It is known from autopsy studies that thromboembolic stroke can be caused by red, white and mixed clots. We therefore examined whether the efficacy of thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) depends on the proportions of fibrin and erythrocytes within thromboembolic material.

METHODS

In 23 rabbits intraarterial thrombolysis with 3 mg rt-PA/kg body weight was started 30 minutes after middle cerebral artery occlusion with either red or white autologous emboli 20 hours old. 20 rabbits served as control. Cerebral perfusion was monitored by MRI.

RESULTS

rt-PA enhanced lysis of red but not of white emboli and decreased the infarct volume only if vascular occlusion was due to red emboli (p <.01). Cerebral perfusion improved only in the red treatment group where the normalized first moment (NFM) decreased (p <.05) and the relative regional cerebral blood volume (rrCBV) reached normal values (p <.05).

CONCLUSION

We suggest that in our animal model the efficacy of thrombolysis increases with the proportion of erythrocytes within thromboembolic material and decreases with its content of fibrin. lf these findings would also be applicable to patients, pretherapeutic estimation of the efficacy of thrombolysis might become feasible because the CT values of red and white thrombi differ.

Intraarterial Thrombolytic Therapy within 3 Hours of the Onset of Stroke

OBJECTIVE

The National Institute of Neurological Disorders and Stroke (NINDS) Recombinant Tissue Plasminogen Activator Stroke Study Group showed that recombinant tissue plasminogen activator (rt-PA) administered intravenously within 3 hours of the onset of ischemic stroke can improve clinical outcome. Intraarterial (IA) thrombolysis has been shown to offer advantages over intravenous (IV) thrombolysis, but experience with this type of therapy within 3 hours of the onset of symptoms has not been reported previously. This study is the first retrospective analysis of a two-institution experience with IA thrombolysis within 3 hours of stroke onset.

METHODS

A total of 36 patients with angiographically demonstrated occlusions were treated with urokinase or rt-PA within 3 hours of stroke onset. Outcome measures included the percentage of patients with no or minimal neurological disability at 30 to 90 days as measured by the modified Rankin Scale, percentage recanalization, incidence of symptomatic intracranial hemorrhage, and mortality rate. The results were compared with those of the NINDS rt-PA study.

RESULTS

The median admission National Institutes of Health Stroke Scale score was 14. Fifty percent of treated patients had a modified Rankin Scale score of 0 or 1 indicating no or little disability at 1 to 3 months compared with 39% of treated patients in the NINDS trial. Recanalization was 75%, symptomatic intracranial hemorrhage was 11% (versus 6.4% with IV rt-PA in the NINDS trial), and the mortality rate was 22% (versus 17% with IV rt-PA in the NINDS trial).

CONCLUSION

The results suggest that IA thrombolysis administered within 3 hours of stroke onset is a feasible and viable alternative to IV rt-PA on the basis of improved clinical outcomes, high recanalization percentage, and comparable mortality rate and despite increased symptomatic intracranial hemorrhage. Whether IA thrombolysis is superior to IV therapy awaits further study.

Relationship Between the Door-to-TIMI-3 Flow Time and the Infarct Size in Patients Suffering From Acute Myocardial Infarction-Analysis Based on the Fibrinolysis and Subsequent Transluminal (FAST-3) Trial-

BACKGROUND

The purpose of this study was to use the findings of a fibrinolysis and subsequent transluminal trial (FAST-3) to evaluate the association between the target time for obtaining a thrombolysis in myocardial infarction (TIMI)-3 flow after arrival at the emergency room with acute myocardial infarction (AMI) and the degree of myocardial salvage.

METHODS AND RESULTS

The FAST-3 trial was administered to 100 patients suffering from AMI. Ranges in the door-to-TIMI-3 flow time (D-T3-time: TIMI-3 flow after arrival at the emergency room) according to quartile were as follows: 30-54 min (quartile 1), 55-77 min (quartile 2), 78-120 min (quartile 3) and 121-330 min (quartile 4). Peak creatine kinase (CK), peak CK-MB, and peak troponin-T values increased in a stepwise fashion across the increasing quartiles of D-T3-time. The left ventricular end diastolic volume index at 30 days after the start of treatment showed low values for quartile 1. In multiple logistic regression analyses for independent predictors of myocardial damage, the adjusted odds ratios for myocardial damage (peak CK>3,000 U/L) in quartiles 3 and 4 of the D-T3-time were 4.0 (95% CI: 1.0-16.1) and 7.0 (95% confidence interval (CI): 1.4-36.0), respectively.

CONCLUSIONS

These findings suggest that physicians should monitor the D-T3-time for at least 55 min.

Thrombolysis 2004: the good, the bad, and the ugly

Nearly 8 years have passed since the U.S. Food and Drug Administration (FDA) released recombinant tissue plasminogen activator (rt-PA) for treatment of patients with acute ischemic stroke. Yet thrombolysis remains an intensely controversial treatment strategy. Clearly thrombolysis is a step forward but there remain problems with its application. The author reviews early investigations that preceded the National Institute of Neurological Disorders and Stroke (NINDS) trial report, discusses NINDS and other randomized trials, and comments on results since the approval and release of tissue type plasminogen activator (tPA). Technology development and use have improved since the release of tPA, and the impact of this development is discussed. Finally, the author shares his advice to doctors about present thrombolytic management of patients with acute ischemic stroke.

[Clinical pathways -- intervention or surgery for acute ischemia of the extremities]

There is still controversial discussion concerning the therapy of limb-threatening ischaemia. In a retrospective study, we investigated and compared surgical and percutaneous interventional methods in the treatment of both embolic and thrombotic vascular occlusions in patients with pre-existing arteriosclerotic disease and attempted to propose therapy guidelines for these methods in the therapy of acute limb ischaemia. Percutaneous mechanical thrombectomy represents a viable therapeutic alternative to surgical or surgical-interventional modalities, particularly in patients with occlusions consisting of soft, embolic material or located in infrapopliteal vessels. The indication for each respective method should be interdisciplinary and must be based on the individual patients' clinical and angiographic findings. Additional intraoperative endovascular procedures increase the range of therapeutic options and permit optimal revascularisation of vessels both proximal and distal to the site of occlusion.

Modulation of PAI-1 and tPA activity and thrombolytic effects of corilagin

In this study, Charlton's and Tomihisa's methods were modified to investigate the thrombolytic effect of corilagin from the Chinese herbal plant Phyllanthus urinaria L., as well as its effect on carotid artery patency status. The activity of type 1 plasminogen activator inhibitor (PAI-1) in rat plasma or platelet-released substances and tissue-type plasminogen activator (tPA) in rat plasma was assayed by use of a chromogenic substrate. The results showed that corilagin had a dose-dependent thrombolytic effect in rats. 5 mg/kg of corilagin produced a nearly similar reperfusion rate to that of 20000 U/kg of urokinase, whereas it produced a lower reocclusion rate than urokinase. Corilagin significantly inhibited PAI-1 activity in rat plasma or platelet-released substances while it elevated plasma tPA activity, in a concentration-dependent manner. Corilagin, however, had no influence on rabbit platelet aggregation. It is indicated that corilagin inhibited PAI-1 activity and increased tPA activity, and this property of corilagin is assumed to be responsible for the thrombolytic effect. Abbreviations. PO:persistent occlusion CR:cyclic reflow PP:persistent patency PAI-1:type 1 plasminogen activator inhibitor tPA:tissue-type plasminogen activator PBS:phosphate buffer solution IC (50):50 % of inhibitory concentration PRP:platelet-rich plasma ADP:adenosine diphosphate AA:arachidonic acid PAF:platelet-activating factor

Prevention of Bleomycin-induced Lung Fibrosis by Aerosolization of Heparin or Urokinase in Rabbits

Bleomycin is a well known fibrogenic agent, provoking an initial adult respiratory distress syndrome-like injury with subsequent strong fibroproliferative response. Severe abnormalities of the alveolar surfactant system, which may be linked to the appearance of alveolar fibrin deposition, have been implicated in the pathogenetic sequence of events. Using a model of standardized aerosol delivery of 1.8 U bleomycin/kg body weight in rabbits, we investigated the influence of repetitive nebulization of heparin or urokinase-type plasminogen activator (u-PA) on the development of lung fibrosis. In an "early" (Days 2-12 postbleomycin) or "late" (Days 14-24 post-bleomycin) treatment protocol, approximately 3,500 U heparin or approximately 6,500 U u-PA was delivered to the bronchoalveolar space. Within four weeks, the bleomycin challenge provoked severe pulmonary fibrosis with reduction of lung compliance, marked increase in soluble collagen (bronchoalveolar lavage fluid) and hydroxyproline content (lung tissue), a typical reticular fibrosis pattern on high-resolution computed tomography, and typical histologic findings. Therapeutic intervention resulted in a far-reaching normalization of compliance, suppression of soluble collagen and hydroxyproline accumulation, and virtual abrogation of the computed tomography scan and histologic features of lung fibrosis, with most prominent effects seen in the early heparin and late u-PA administration. No bleeding complications occurred. These findings strongly support the concept that alveolar fibrin generation is an important event in the development of postbleomycin lung fibrosis. "Compartmentalized" anticoagulation and/or fibrinolysis via inhalational deposition of interventional agents in the alveolar compartment may thus offer a new therapeutic strategy for prevention of fibrosis.

Intraarterielle Lysetherapie bei akuter Extremit�tenisch�mie

Acute limb ischemia is associated with a high risk of death and loss of the extremity. To restore the blood flow, several percutaneous thrombolytic techniques were developed. To achieve a targeted thrombus infiltration, the continuous application of low-dose urokinase or recombinant tissue plasminogen activator using a specific lysis catheter with sideholes is preferable. Concerning the amputation-free survival, thrombolysis is superior to surgery for occlusions of native vessels or bypass grafts that are not older than 2 weeks. Furthermore, the percutaneous approach permits the simultaneous treatment of the underlying lesion by angioplasty or stent implantation after dissolution of the occluding thrombus. The higher risk of complications must be balanced against risks of surgery in each patient.