Thrombolytic therapy for acute myocardial infarction: what dose should be used?

Most of the concern about dosing of t-PA as presented in the literature is related to the lower weight groups and the increased incidence of bleeding in this patient population. Not much is known or written about what doses of t-PA should be used in the grossly obese patient with an MI. In the patient described briefly at the beginning of this editorial, the usual accelerated dose regimen was used. Although the patient's symptoms resolved quickly, ST-segment elevation never returned to baseline. Creatine kinase-MB and troponin I rose and fell slowly. He had an uneventful course in the hospital but my impression is that he did not reperfuse his myocardium. Unfortunately, because of his weight, we were unable to evaluate this patient with either coronary angiography or echocardiography. As I think more about this case, I am of the opinion that the patient was underdosed with 100 mg of t-PA. If I had it to do over again, I would use a higher dose of t-PA. I would be interested to hear how others would have treated the patient.

Loco-regional thrombolysis for deep vein thrombosis: fact or fiction? A study of hemostatic parameters

Loco-regional thrombolysis for deep-vein thrombosis (DVT) has been claimed to be equally effective and safe compared with systemic thrombolysis. It is not known whether a loco-regional thrombolytic effect exists and of what it might consist. To investigate this issue, we studied eight patients with DVT undergoing loco-regional thrombolysis with 20 mg alteplase infused over 4 h in a dorsal foot-vein of the affected leg, while the leg was kept tightly bandaged; alteplase infusions were repeated every 24 h, the number of therapy cycles (TC) was seven, and full-dose heparin was given. For coagulation analyses, 'loco-regional' blood samples were taken from a vein of the affected leg and 'systemic' samples were taken from an antecubital vein. After a median number of six TC, good partial reperfusion was achieved in 4/8 patients, moderate partial reperfusion in 2/8, major bleedings occurred in 2/8, and minor bleedings in 1/8 patients. During the first TC, recombinant tissue-type plasminogen activator (rtPA) activity and antigen, as well as FgDPs and d-dimers, were elevated significantly loco-regionally over systemic values, and a complete breakdown of plasmin-inhibitor activity occurred with only a slight systemic reduction; no other differences were found. During successive TC, differences in rtPA-activity and -antigen levels decreased, and no significant differences were found for all other parameters. Thus, a local fibrinolytic effect was demonstrable during loco-regional thrombolysis for DVT; the magnitude of this effect diminished during successive TC, giving rise to the hypothesis that the fibrinolytic efficacy may be decreased due to growing, antifibrinolytic activity. The preserved, loco-regional plasmin-inhibitor activities during the later TC, in contrast to the complete breakdown during the first TC, suggest that part of the enhanced antifibrinolytic activity is due to loco-regionally increased plasmin-inhibitor activity. The ultimate goal of loco-regional thrombolysis, the induction of local fibrinolysis without systemic effects, has not, however, been achieved.

[Fibrinolytic therapy in thrombosis of a mitral valve prosthesis]

A 48-year-old woman presented with progressive dyspnea due to thrombosis of a mitral valve prosthesis. The patient had undergone mitral valve replacement (St. Jude Medical) six years prior to admission because of mitral stenosis (Class III); three years later the prosthesis had to be replaced (St. Jude Medical) because of valve thrombosis. At admission, transesophageal echocardiography showed a thrombus on the atrial side of the fixed valve leaflet and a thrombus (2.4 x 1.6 cm) floating from the left atrial roof. Because of the previous thoracotomies, thrombolysis was initiated despite the mobile thrombus with the attendant risk of embolization. Urokinase was infused in a dose to maintain the fibrinogen level around 100 mg/dl. After 24 h, the mean pressure gradient across the prosthetic mitral valve (measured by doppler echocardiography) had decreased from 23 to 11 mmHg. After 13 days of this modified thrombolytic regimen, the clinical symptoms of the patient had resolved and echocardiography showed a normal function of the prosthetic mitral valve without evidence of residual thrombosis. This patient demonstrates that prolonged cautious thrombolysis can be effective for the treatment of prosthetic valve thrombosis in hemodynamically moderately compromised patients.

[Ischemia of the lower extremity due to a persistent a. ischiadica--a possible interventional therapeutic approach]

The sciatic artery is a rarely seen variant of the vessels of the lower limb. Anatomically it is the prolongation of the inferior gluteal artery and accompanies the sciatic nerve from the sciatic foramen to the knee. More than other vessels, the sciatic artery shows vasculopathies like diffuse dilatation or aneurysms. This report describes an interesting case of embolic acute ischemia, caused by a persistent sciatic artery with an aneurysm. We treated the ischemia with intra-a. lysis and bridged the aneurysm with an covered stent.

Timing of recanalization after tissue plasminogen activator therapy determined by transcranial doppler correlates with clinical recovery from ischemic stroke

BACKGROUND

The duration of cerebral blood flow impairment correlates with irreversibility of brain damage in animal models of cerebral ischemia. Our aim was to correlate clinical recovery from stroke with the timing of arterial recanalization after therapy with intravenous tissue plasminogen activator (tPA).

METHODS

Patients with symptoms of cerebral ischemia were treated with 0.9 mg/kg tPA IV within 3 hours after stroke onset (standard protocol) or with 0.6 mg/kg at 3 to 6 hours (an experimental institutional review board-approved protocol). National Institutes of Health Stroke Scale (NIHSS) scores were obtained before treatment, at the end of tPA infusion, and at 24 hours; Rankin Scores were obtained at long-term follow-up. Transcranial Doppler (TCD) was used to locate arterial occlusion before tPA and to monitor recanalization (Marc head frame, Spencer Technologies; Multigon 500M, DWL MultiDop-T). Recanalization on TCD was determined according to previously developed criteria.

RESULTS

Forty patients were studied (age 70+/-16 years, baseline NIHSS score 18.6+/-6.2). A tPA bolus was administered at 132+/-54 minutes from symptom onset. Recanalization on TCD was found at the mean time of 251+/-171 minutes after stroke onset: complete recanalization occurred in 12 (30%) patients and partial recanalization occurred in 16 (40%) patients (maximum observation time 360 minutes). Recanalization occurred within 60 minutes of tPA bolus in 75% of patients who recanalized. The timing of recanalization inversely correlated with early improvement in the NIHSS scores within the next hour (polynomial curve, third order r(2)=0.429, P<0.01) as well as at 24 hours. Complete recanalization was common in patients who had follow-up Rankin Scores if 0 to 1 (P=0.006). No patients had early complete recovery if an occlusion persisted for >300 minutes.

CONCLUSIONS

The timing of arterial recanalization after tPA therapy as determined with TCD correlates with clinical recovery from stroke and demonstrates a 300-minute window to achieve early complete recovery. These data parallel findings in animal models of cerebral ischemia and confirm the relevance of these models in the prediction of response to reperfusion therapy.

Superselective ophthalmic arterial fibrinolysis with urokinase for recent severe central retinal venous occlusion: initial experience

PURPOSE

To investigate the effects of local ophthalmic arterial fibrinolysis on central retinal venous occlusion (CRVO).

MATERIALS AND METHODS

Thirteen patients had recent severe nonischemic CRVO for which no alternative therapy was available. A flow-guide microcatheter was introduced coaxially via the femoral artery into the ophthalmic arterial ostium, and urokinase was perfused for 40 minutes. Vision, funduscopic findings, and retinal perfusion were assessed during 1 year of follow-up.

RESULTS

Five of the 13 patients treated experienced visual improvement (P =.05) and retinal perfusion within 24-48 hours. Vision returned to normal within 24-48 hours in three patients, within 1 week in one patient, and within 1 month in one patient. These five patients exhibited progressive lesion regression within 2-4 weeks at funduscopy. Their clinical course prior to treatment resembled that of combined central retinal arterial occlusion (CRAO) and CRVO, which typically has a poor visual outcome. One patient relapsed 1 month after fibrinolysis. Of the remaining eight patients, one had normal vision at 12 months, and seven had no improvement. No technical complications were observed.

CONCLUSION

Although there was no control group, the short period between fibrinolysis and substantial visual improvement, combined with marked retinal perfusion improvement, suggests that fibrinolysis is beneficial for CRVO, especially for recent CRAO and CRVO.

Combined cataract extraction and submacular blood clot evacuation for globe perforation caused by retrobulbar injection

A 45-year-old woman, originally scheduled for cataract surgery in the left eye, was referred for management of a globe perforation noticed after the retrobulbar injection of an anesthetic solution. There was a moderate degree of vitreous hemorrhage, and initial visual acuity was hand movement. A submacular blood clot of about 4-disc diameter was detected when the vitreous hemorrhage gradually cleared. One week after the incident, combined phacoemulsification, intraocular lens implantation, pars plana vitrectomy, and submacular clot removal using tissue plasminogen activator (tPA) as an adjunct were performed. Recovery was uneventful. At the last follow-up 6 months after surgery, best corrected visual acuity was 20/30.

[Rheological properties of blood during pulsatile pharmacomechanical and continuous local thrombolysis]

BACKGROUND

The aim of the work was to find out whether the controlled administration of a thrombolytic directly into the arterial occlusion could prevent formation of the systemic lytic state, which may result in distant bleeding complications.

METHODS AND RESULTS

In patients subjected to pulsatile pharmacomechanical (94 patients) and local continual thrombolysis (74 patients) changes in blood and plasma viscosity, coagulation tests, fibrinogen levels and some other parameters were investigated.

CONCLUSIONS

Pulsatile pharmacomechanical thrombolysis, similarly to other forms of thrombolysis, is accompanied with systemic lytic state and the risk of unwanted resorption of the hemostatic thrombosis. Urokinase administration brings about regress of systemic changes, which is similar to the use of either tested thrombolytic administration. As treatment by the continual thrombolysis takes is approximately 40 times longer, the risk of systemic lytic state and bleeding complication growths.

High levels of platelet inhibition with abciximab despite heightened platelet activation and aggregation during thrombolysis for acute myocardial infarction: results from TIMI (thrombolysis in myocardial infarction) 14

BACKGROUND

We evaluated platelet activation and aggregation in patients with acute myocardial infarction (AMI) treated with thrombolytic therapy alone or with reduced-dose thrombolysis and concomitant abciximab.

METHODS AND RESULTS

The study was performed in 20 control subjects and 51 patients with AMI before and after reperfusion with either alteplase or reteplase or reduced doses of these agents with concomitant abciximab. Platelet activation was assayed by platelet surface expression of P-selectin. Turbidometric platelet aggregation in response to ADP was measured in patients before thrombolytic therapy and 90 minutes and 24 hours after the beginning of thrombolytic therapy. P-selectin expression was greater at baseline in patients than normal control subjects (30.4% versus 9. 8%, P<0.0001) but was identical between the 2 groups after stimulation with ADP (64.4% versus 69.3%, P=0.37). However, at 24 hours, basal P-selectin expression declined in patients (P=0.0025 versus baseline), whereas ADP-stimulated P-selectin expression was lower in patients than in control subjects (48% versus 69%, P=0. 0004). When combined with reduced doses of either alteplase or reteplase, abciximab achieved 91% and 83% inhibition of 5 and 20 micromol/L ADP-induced platelet aggregation, which decreased to 46% and 40%, respectively, at 24 hours. No appreciable difference in the platelet inhibition profile of abciximab was observed between the 2 thrombolytics.

CONCLUSIONS

Platelet activation and aggregation are heightened in the setting of thrombolysis for AMI. Despite this enhanced level of platelet activation, abciximab, combined with a reduced-dose thrombolytic, inhibited platelet aggregation similarly to the level reported in elective settings.

Evaluation of thrombolysis and angioplasty in a porcine iliac artery thrombosis model: application of endovascular stent-graft-induced thrombosis

PURPOSE

To develop a novel endovascular thrombosis model in the porcine iliac artery for the evaluation of thrombolysis and angioplasty.

MATERIALS AND METHODS

A stent-inversion-graft (SIG) model combining either a 3-mm or 5-mm tapered expandable polytetrafluoroethylene (ePTFE) graft attached within a self-expandable, 10-mm nitinol stent was placed in the left common iliac artery via an ipsilateral common femoral artery approach in 24 pigs. When the iliac artery was thrombosed, urokinase (250,000 IU) plus heparin (1,000 units) were pulse sprayed via a contralateral femoral approach (n = 12). Saline pulse-spray was used as a control group (n = 12). Balloon angioplasty was performed to eliminate the stenotic tapered graft within the stent after successful thrombolysis. The efficacy of the thrombolysis was assessed with use of intravascular ultrasound (IVUS) and arteriogram.

RESULTS

Both the 3-mm tapered and 5-mm tapered SIG models caused iliac artery occlusion in 22 +/- 5 and 41 +/- 9 minutes, respectively, after the deployment. Luminal patency was re-established successfully in all occluded arteries after urokinase infusion. Angioplasty was successful in eliminating the tapered stenosis and restoring the normal diameter in all iliac arteries treated with urokinase. Complete thrombolysis was achieved in both models treated with urokinase.

CONCLUSION

This novel endovascular approach of inducing arterial thrombosis is simple to perform and reliably produces arterial thrombosis. The intraluminal stenosis is also amenable to angioplasty. This model is useful for the evaluation of antithrombotic treatment modality and adjunctive endovascular interventions.

Pneumatic displacement of submacular hemorrhage

Patients with thick submacular hemorrhage complicating age-related macular degeneration and other disorders typically have a poor visual prognosis. A new outpatient procedure, consisting of intravitreal injection of tissue plasminogen activator and gas followed by brief prone positioning, is effective in displacing thick submacular blood and facilitating visual improvement in most patients. Injection of gas alone also appears to be effective in many eyes. The procedure is technically simple and the rate of serious complications appears to be acceptably low. Although the final visual outcome is often limited by progression of age-related macular degeneration, significant and stable visual recovery is possible in selected eyes. Prospective clinical trials are needed to clarify the role for intravitreal tissue plasminogen activator and to provide definitive outcome comparisons with other management approaches.

Urokinase cisternal irrigation therapy for prevention of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage: a study of urokinase concentration and the fibrinolytic system

BACKGROUND AND PURPOSE

Cisternal irrigation therapy with urokinase (UK) was performed in multiple institutions to prevent symptomatic vasospasm. The efficacy and safety of this therapy were evaluated, and the optimal concentration of UK was estimated.

METHODS

This therapy was performed in 28 patients who underwent surgery within 72 hours of the onset of severe subarachnoid hemorrhage (Fisher's group 3, CT number [Hounsfield units] >60). After the aneurysm was clipped, irrigation tubes were placed in the Sylvian fissure (inlet) unilaterally and in the prepontine or chiasmatic cistern (outlet). Lactated Ringer's solution with UK (30, 60, or 120 IU/mL) was infused at a rate of 30 mL/h. The presence of symptomatic vasospasm was evaluated by changes in the clinical symptoms and the presence of a new low-density area on CT scan. Drained irrigation fluid and peripheral blood were examined chronologically to evaluate the fibrinolytic system.

RESULTS

Symptomatic vasospasm was observed transiently in 3 cases (10.7%) without any low-density area on CT scan. In the 120-IU/mL group, no symptomatic vasospasm occurred. Analysis of drainage fluid suggested that UK 120 IU/mL is effective. The mean values of total drained blood volume for the respective groups were as follows: 58 mL in 30 IU/mL, 106 mL in 60 IU/mL, and 143 mL in 120 IU/mL. No abnormal changes were observed in the coagulative and fibrinolytic systems after UK irrigation.

CONCLUSIONS

These results suggest that cisternal irrigation therapy with UK is safe and effective for the prevention of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage.

Treatment of complicated pleural effusion with intracavitary urokinase in children

Intrapleural administration of fibrinolytic agents such as urokinase (UK) has been advocated as an alternative method to manage complicated pleural effusion (CPE). Despite the increasing number of empyemas successfully treated with UK in adults, the experience in children is limited to a few cases. We report the results of image-guided catheter drainage (IGCD) with intracavitary instillation of UK in six children with CPE. Urokinase (25,000-100, 000 IU) was diluted in 20 mL of normal saline and instilled into the pleural cavity via a percutaneously placed drainage catheter. After 4 hr, the clamped catheter was released and connected to water-seal suction at a negative pressure of 20 cm H(2)O. UK instillation was repeated daily until no further drainage occurred. During IGCD, repeated radiographic and ultrasound imaging determined the location and amount of any remaining pleural fluid. Mean duration of hospital stay before initiating UK therapy was 4.3 days. Mean duration of catheter drainage before initiating UK therapy was 3.5 days, and the mean total drainage was 86 mL. All patients had an increase in chest tube drainage within 24 hr after the first instillation of UK. The mean net total drainage after UK instillation was 281 mL, most of the drainage being occurring in the first 2 days of treatment. Mean hospital stay following UK treatment was 5.8 days, and the average total duration of hospital stay was 13.8 days. No complications and no adverse events occurred during treatment with UK. Complete resolution of the consequences of the pleural effusion was observed in all patients at follow-up. Our results suggest that IGCD with adjunctive UK therapy is a reliable, simple, and safe approach to treat CPE, and it can reduce the risks associated with thoracotomy and decortication.

Usefulness of postischemic thrombolysis with or without neuroprotection in a focal embolic model of cerebral ischemia

OBJECT

Recent studies have shown that the use of thrombolysis in the setting of acute stroke is associated with an increased risk of cerebral hemorrhage. The time of onset of symptoms to initiation of medication and the dose levels of the thrombolytic agents are important determinants for the risk of cerebral hemorrhage. The authors evaluated the time course of thrombolysis-related hemorrhages in experimental settings and tested whether the addition of neuroprotective medication augments the efficacy of thrombolysis and reduces the incidence of hemorrhages.

METHODS

Male Wistar rats were subjected to right middle cerebral artery embolization with an autologous thrombus and were then randomly assigned to one of the following groups: Group 1, saline-treated (2 hours after ischemic insult) animals as controls; Groups 2 to 4, high-dose urokinase (5,000 U/kg) at 2, 3, and 6 hours after the insult; Group 5, low-dose urokinase (2,500 U/kg) at 2 hours after the insult; Group 6, 20 mg/kg topiramate (TPM) at 2 hours after the insult; Group 7, a combination of 20 mg/kg TPM at 2 hours and low-dose urokinase (2,500 U/kg) at 6 hours after the insult; and Group 8, 20 mg/kg TPM (20 mg/kg) at 2 hours and high-dose urokinase (5,000 U/kg) at 2 hours after the insult. Neurological behavior and the infarct volume in the brain were assessed following cerebral embolism and the various treatments. All animals in the single therapy and low-dose combination groups survived surgery. Three of eight animals treated with high-dose urokinase alone at 6 hours and three of six animals in the combined high-dose urokinase and TPM group developed fatal intracerebral hemorrhages. There was a significantly better neurological outcome at 24 hours in the animals treated with either medication compared with controls. The volume of the infarct in the saline-treated group was 54.2 +/- 9%. The use of TPM at 2 hours led to a decrease in the infarct to 20.1 +/- 11.2% (p < 0.01). Treatment with urokinase at 6 hours after the occlusion showed a trend toward protection; the infarct volume was 31.9 +/- 14.1% (p < 0.05). The addition of TPM to low- or high-dose urokinase achieved better neuroprotection (8.2 +/- 6% and 11.9 +/- 10.7%, respectively; both p < 0.01).

CONCLUSIONS

In this study the authors show that the volume of the infarct can be significantly decreased with 2 to 6-hour delayed intraarterial thrombolysis with urokinase and that the efficacy of thrombolysis may be enhanced by combining neuroprotective agents like TPM. It is also shown that low-dose combination therapy may decrease the likelihood of cerebral hemorrhage.

Retinal toxicity of commercial intravitreal tissue plasminogen activator solution in cat eyes

BACKGROUND

We previously reported retinal toxic reactions in rabbit eyes receiving intravitreal injections of commercial tissue plasminogen activator (tPA) in concentrations greater than or equal to 50 microg/0.1 mL, and recent clinical experience suggests that intravitreal tPA solution may produce toxic effects in human eyes. We therefore investigated the dose-dependent retinal toxicity of intravitreal commercial recombinant tPA solution in cat eyes, which have a vascularized inner retina and vitreous volume similar to that of human eyes.

METHODS

Commercial tPA in L-arginine solution was injected into the mid vitreous cavity of normal cat eyes in doses of 25, 50, 75, and 100 microg/0.1 mL and 200 microg/0.2 mL. Control (fellow) eyes received an equal volume of sterile saline solution. After injection, eyes were evaluated by ophthalmoscopy and electroretinography for 14 days and then enucleated for histopathological evaluation.

RESULTS

Fundus pigmentary alterations were observed in eyes receiving doses greater than or equal to 50 microg/0.1 mL. Changes were centered in the area around the injection site, and the area's size increased in proportion to the dosage. Mean electroretinography B-wave amplitude measured at 14 days was significantly reduced in eyes receiving greater than or equal to 50 microg of tPA in a dose-dependent fashion. Light microscopy of the involved areas showed loss of photoreceptor elements with necrosis and proliferation of the retinal pigment epithelium.

CONCLUSION

Intravitreal injection of commercial tPA solution results in dose-dependent retinal toxicity in cat eyes.

CLINICAL RELEVANCE

Because cat eyes are similar to human eyes regarding retinal vascularity and vitreous volume, intravitreal injections of commercial tPA (with L-arginine vehicle) in concentrations greater than 25 microg/0.1 mL are potentially unsafe in human eyes.

Endovascular treatment of multiple visceral artery paradoxical emboli with mechanical and pharmacological thrombolysis

PURPOSE

To report a case of paradoxical emboli to multiple visceral vessels treated with both mechanical (AngioJet device) and pharmacological (urokinase) thrombolysis.

METHODS AND RESULTS

A 72-year-old man presented with a 48-hour history of symptomatic right renal ischemia, which was treated with heparinization. Five days later, an abrupt creatinine elevation prompted arteriography, which demonstrated thromboembolism of the superior mesenteric artery (SMA) and both renal arteries. The AngioJet aspiration device was employed to successfully remove the clot from the SMA; urokinase infusion restored flow to the left kidney. At the 16-month follow-up evaluation, the patient was normotensive without medication and had a stable creatinine (1.4 mg/dL).

CONCLUSIONS

Because of its speed and minimal morbidity, the AngioJet device may be an attractive alternative to surgical embolectomy or pharmacological thrombolysis in highly selected cases of acute visceral artery thromboembolism.

Tissue plasminogen activator in the treatment of vitreoretinal diseases

Tissue plasminogen activator (tPA) is a thrombolytic agent that activates plasminogen into plasmin almost exclusively in the presence of fibrin. Intraocular injection of tPA has been proposed for the treatment of vitreoretinal diseases, such as vitreous hemorrhage, postvitrectomy fibrin formation, submacular hemorrhage, retinal vascular occlusive disorders, suprachoroidal hemorrhage and endophthalmitis. Currently, intraocular tPA is only used in the treatment of postvitrectomy fibrin formation and submacular hemorrhage. For other indications, tPA has not been shown to be safe or effective. This article reviews the use of tPA in the treatment of vitreoretinal disorders.

Intravenous tissue-type plasminogen activator for treatment of acute stroke: the Standard Treatment with Alteplase to Reverse Stroke (STARS) study

CONTEXT

Tissue-type plasminogen activator (tPA) is the only therapy for acute ischemic stroke approved by the Food and Drug Administration.

OBJECTIVE

To assess the safety profile and to document clinical outcomes and adverse events in patients treated with intravenous tPA for acute stroke in clinical practice.

DESIGN AND SETTING

Prospective, multicenter study of consecutive patients enrolled between February 1997 and December 1998 at 57 medical centers in the United States (24 academic and 33 community).

INTERVENTION

Intravenous tPA (recombinant alteplase).

PATIENTS

Three hundred eighty-nine patients with a mean age of 69 years (range, 28-100 years); 55% were men.

MAIN OUTCOME MEASURES

Time intervals between stroke symptom onset, hospital arrival, and treatment with tPA; pretreatment computed tomographic scan results, intracerebral hemorrhage, and major systemic bleeding. The modified Rankin Scale score was used to assess clinical outcomes at 30 days.

RESULTS

Median time from stroke onset to treatment was 2 hours 44 minutes, and the median baseline National Institutes of Health Stroke Scale score was 13. The 30-day mortality rate was 13%. At 30 days after treatment, 35% of patients had very favorable outcomes (modified Rankin score, 0-1) and 43% were functionally independent (modified Rankin score, 0-2). Thirteen patients (3.3%) experienced symptomatic intracerebral hemorrhage, including 7 who died. Twenty-eight patients (8.2%) had asymptomatic intracerebral hemorrhage within 3 days of treatment with tPA. Protocol violations were reported for 127 patients (32.6%), and included treatment with tPA more than 3 hours after symptom onset in 13.4%, treatment with anticoagulants within 24 hours of tPA administration in 9.3%, and tPA administration despite systolic blood pressure exceeding 185 mm Hg in 6.7%. A multivariate analysis found predictors of favorable outcome to be a less severe baseline National Institutes of Health Stroke Scale score, absence of specific abnormalities (effacement or hypodensity of >33% of the middle cerebral artery territory or a hyperdense middle cerebral artery) on the baseline computed tomographic scan, an age of 85 years or younger, and a lower mean arterial pressure at baseline.

CONCLUSIONS

This study, conducted at multiple institutions throughout the United States, suggests that favorable clinical outcomes and low rates of symptomatic intracerebral hemorrhage can be achieved using tPA for stroke treatment.

Augmented experimental pulse-spray thrombolysis with tissue plasminogen activator, enabling dose reduction by one or more orders of magnitude

PURPOSE

To critically evaluate and optimize methodologic details of pulse-spray thrombolysis with tissue plasminogen activator (tPA) in a subacute rabbit inferior vena cava thrombosis model.

MATERIALS AND METHODS

Occlusive inferior vena cava thrombi were produced in 104 rabbits and 2 days later were treated for 1 hour with pulse-spray thrombolysis using tPA. Methodologic variables included pulse frequency, concentration and amount of tPA, infusion versus pulse therapy, and admixture of heparin. After the rabbits were killed, residual thrombus was weighed.

RESULTS

The authors' earlier standard regimen (3 mg of tPA in 6 mL of heparinized saline, 0.2-mL hand pulses, frequency 1 pulse per 2 minutes) produced 60% mean lysis. Optimization involved increasing the pulse frequency to two per minute and decreasing tPA concentration by 98% to 0.01 mg/mL, modifications that produced 22% more thrombolysis, despite 92% reduction in amount of tPA to 0.25 mg.

CONCLUSION

Consistent with the in vitro work of other investigators, a roughly bell-shaped dose-response curve was elicited in vivo for pulse-spray with tPA. By diluting tPA to an optimal level, and increasing pulse frequency to two per minute, thrombolysis was markedly augmented. These results suggest that the conventional dose of tPA used for clinical pulse-spray thrombolysis can be reduced by one to two orders of magnitude, possibly markedly reducing procedural risk.

Use of tissue-type plasminogen activator for acute ischemic stroke: the Cleveland area experience

CONTEXT

Little is known regarding outcomes after intravenous tissue-type plasminogen activator (IV tPA) therapy for acute ischemic stroke outside a trial setting.

OBJECTIVE

To assess the rate of IV tPA use, the incidence of symptomatic intracerebral hemorrhage (ICH), and in-hospital patient outcomes throughout a large urban community.

DESIGN

Historical prospective cohort study conducted from July 1997 through June 1998.

SETTING

Twenty-nine hospitals in the Cleveland, Ohio, metropolitan area.

PATIENTS

A total of 3948 patients admitted to a study hospital with a primary diagnosis of ischemic stroke (International Classification of Diseases, Ninth Revision, Clinical Modification code 434 or 436).

MAIN OUTCOME MEASURES

Rate of IV tPA use and occurrence of symptomatic ICH among patients treated with tPA; proportion of patients receiving tPA whose treatment deviated from national guidelines; in-hospital mortality among patients receiving tPA compared with that among ischemic stroke patients not receiving tPA and with mortality predicted by a model.

RESULTS

Seventy patients (1.8%) admitted with ischemic stroke received IV tPA. Of those, 11 patients (15.7%; 95% confidence interval [CI], 8.1%-26.4%) had a symptomatic ICH (of which 6 were fatal) and 50% (95% CI, 37.8%-62.2%) had deviations from national treatment guidelines. In-hospital mortality was significantly higher among patients treated with tPA (15.7%) compared with patients not receiving tPA (5.1%, P<.001) and compared with the model's prediction (7.9%; P<.006).

CONCLUSIONS

A small proportion of patients admitted with acute ischemic stroke in Cleveland received tPA; they experienced a high rate of ICH. Cleveland community experience with tPA for acute ischemic stroke may differ from that reported in clinical trials.

[Thrombolytic therapy for acute myocardial infarction: circadian sensitivity]

AIM

To identify additional factors which may influence the results of thrombolytic therapy (TT) with streptokinase in acute myocardial infarction (AMI).

MATERIALS AND METHODS

122 case histories of males treated with streptokinase for AMI were analyzed. The patients were subdivided into 3 groups according to TT effectiveness: effective (74 patients-60.7%, age 61.3 +/- 11.9 years, group 1); probably successful (13 patients-10.7%, age 68.9 +/- 9.3, group 2), unsuccessful (35 patients-28.6%, age 64.9 +/- 13.6, group 3).

RESULTS

Between groups 1 and 3 there were no differences by age, AMI location, coronary risk factors (smoking, hypertension, diabetes mellitus, hyperlipidemia, family history of coronary disease), previous MI, Q and non-Q-wave MI prevalence. Significant differences were, on the contrary, obtained for the Killip class (1.82 +/- 0.46 vs 2.26 +/- 0.74, p = 0.0001), fibrinogen level before TT (314.6 +/- 87.2 vs 215.5 +/- 121.9 mg%, p = 0.003), LVEF% (by echo) 24 hours after the treatment (41.9 +/- 6.3 vs 36.5 +/- 7.8, p = 0.0001), time delay of TT from AMI symptoms onset (2.45 +/- 1.14 vs 3.08 +/- 1.73 hours, p = 0.014). Circadian variation has been discovered for efficacy of streptokinase: in the evening (from 16 to 24 pm) the effectiveness of TT was highest--38.0% vs 14.7% (p = 0.005) and at night (from 24 pm to 08 am) the effect was the lowest--22.5% vs 41.2% (p = 0.024). Smoking was not an independent factor for TT success.

CONCLUSION

Multiple regression analysis (step by step) has shown that the main independent determinants for TT success in males were: Killip class (p = 0.002), time delay of TT (p = 0.014), day time of TT beginning (p = 0.023) and MI location (p = 0.123). These findings may have several clinical implications, for example: dose adjustment of streptokinase for the time of day or preference for primary coronary angioplasty in the morning.

Mechanical versus chemical thrombolysis: an in vitro differentiation of thrombolytic mechanisms

PURPOSE

To assess differing mechanisms of thrombolysis determining time to reperfusion, completeness of thrombus dissolution, and embolic potential.

MATERIALS AND METHODS

An in vitro perfusion model designed to mimic arterial flow conditions was created. Bifurcated limbs allowed continuous flow through one channel and the placement of radiolabeled (iodine-125) thrombus housed in a 5-cm segment of polytetrafluoroethylene graft in the other. The three experimental groups consisted of a standard continuous urokinase infusion, a pulsed pressurized injection of saline, and a similar injection with urokinase. A continuous infusion of 5% dextrose served as a control group. Time to reflow (as assessed with ultrasonic flow monitoring), completeness of thrombus dissolution (I-125 liberated into solution), and the number and size of embolic particles produced (detected by a series of graduated filter sizes) were analyzed.

RESULTS

Time to reflow was significantly faster for both groups when pressurized injections were used (P < .001). There was no reflow in the control arm at 90 minutes. Completeness of thrombus dissolution was higher when a continuous infusion of urokinase was used in comparison to either of the power injection groups or the control (P < .05). The amount of embolic debris produced was significantly lower with a continuous infusion of urokinase compared with either of the power lysis groups (P < .05), but significantly greater than the control arm (P < .001). The size of the embolic particles in the power pulsed lysis groups was significantly decreased by the addition of urokinase (P < .05).

CONCLUSIONS

Reflow is more rapidly established by the use of mechanical means. However, a less complete dissolution of thrombus in conjunction with a greater amount of embolic debris is achieved with this approach. The size of the embolic particles produced is reduced by the addition of a thrombolytic agent.

The effects of thrombus, thrombectomy and thrombolysis on endothelial function

OBJECTIVE

this study was undertaken to examine and compare the effects of thrombus, thrombectomy, and thrombolysis on endothelial function as measured by endothelium-dependent vasorelaxation (EDR).

METHODS

adult, male New Zealand white rabbits underwent ligation of the left common iliac to femoral artery to induce thrombosis and were then randomly assigned to one of five groups, n=6 in each. Group A consisted of ligation and thrombosis for 4 h. Group B underwent similar ligation for 4 h, but without intraluminal thrombus present. Following 4 h of ligation and thrombosis, Group C underwent thrombectomy while group D was treated with urokinase (UK), 4000 U/min for 30 min. Group E underwent UK infusion alone. The right external iliac artery served as control vessel in each group. All arteries were removed and endothelial function was determined by measuring EDR.

RESULTS

the presence of thrombus reduced EDR by 50% (group A) compared to control. Vessels with interrupted flow, but not exposed to thrombus, retained normal EDR (group B). Thrombectomy decreased EDR significantly (group C) compared to thrombolysis (group D) and control. UK did not significantly alter EDR (groups D, E).

CONCLUSIONS

exposure of endothelium to thrombus significantly decreases EDR. EDR was not affected by interruption of blood flow in the absence of thrombus. Thrombectomy appeared to cause a further additive insult to the endothelium. In contrast, thrombolysis with UK preserved residual endothelial function. These data suggest that it is important to differentiate the effects of thrombus on endothelium from effects due to thrombectomy or thrombolysis when evaluating treatment modalities for arterial thrombosis.

Cisternal irrigation therapy with urokinase and ascorbic acid for prevention of vasospasm after aneurysmal subarachnoid hemorrhage. Outcome in 217 patients

BACKGROUND

Cisternal irrigation therapy with urokinase and ascorbic acid was introduced to prevent symptomatic vasospasm after aneurysmal subarachnoid hemorrhage (SAH). To dissolve and wash out the subarachnoid clot, cisternal irrigation with urokinase is used. Ascorbic acid is added to degenerate oxy-hemoglobin, one of the strongest spasmogenic substances, into verdohemelike products, which are nonspasmogenic. The efficacy and safety of this therapy were evaluated.

METHODS

This therapy was performed consecutively in 217 patients. The degree of SAH of the patients was classified as Fisher CT Group 3, and the highest CT number (Hounsfield number) exceeded 60 in the SAH, which suggested a significant risk for symptomatic vasospasm. All patients underwent surgery within 72 hours from the onset of SAH. After clipping the aneurysm, irrigation tubes were placed in the Sylvian fissure (inlet) unilaterally or bilaterally and in the prepontine or chiasmal cistern (outlet). Lactated Ringer's solution with urokinase (120 IU/mL) and ascorbic acid (4 mg/mL) was infused at a rate of 30 mL/hour/side for approximately 10 days.

RESULTS

Of the 217 patients studied, symptomatic vasospasm was observed in 6 cases (2.8%), and two of these six cases (0.9%) demonstrated sequelae. The average total blood volume calculated from the drainage fluid was approximately 114 mL. Analysis of the absorption spectrum of the drainage fluid revealed disappearance of the oxy-hemoglobin-specific 576-nm peak. Complications occurred in eight patients during irrigation therapy; two patients experienced seizures, two patients developed meningitis, and four patients had an intracranial hemorrhage. However, all of these patients recovered without neurological deficits.

CONCLUSIONS

These results suggest that cisternal irrigation therapy with urokinase and ascorbic acid is effective in preventing symptomatic vasospasm after aneurysmal SAH.

Accelerated infusion of streptokinase in acute myocardial infarction results in better TIMI flow grade in infarct-related artery

Bolus followed by rapid infusion of tissue plasminogen activator results in higher grade of TIMI flow in infarct-related artery as compared to slow infusion. In the present study, an accelerated regimen of streptokinase given over 15 minutes was compared with conventional infusion over one hour in 47 patients presenting within 12 hours of acute myocardial infarction. Forty-seven patients (44 males, 3 females; mean age 54.0 +/- 1.1 years) were randomly allocated to receive 1.5 million units of streptokinase either over 15 minutes (group 1, n = 24) or over one hour (group 2, n = 23) at a mean interval of 5.4 +/- 3.6 hours after onset of symptoms. All the patients received aspirin and intravenous heparin (1000 U/hr) for 96 hours after thrombolysis. Coronary angiography was performed in 43 patients (22 in group 1, 21 in group 2) prior to discharge from the hospital (mean 7 +/- 2.1 days after acute myocardial infarction) and patency of the infarct-related artery and grade of TIMI flow were determined. Infarct-related artery was patent (TIMI 2/3 flow) in 19 (86.4%) patients in group 1 as compared to 12 (57.1%) in group 2 (p < 0.05). TIMI grade 3 flow in the infarct-related artery was present in 13 (59.1%) in group 1 as compared to 7 (33.3%) in group 2 (p = 0.1). There was no significant difference between group 1 and 2 in time of presentation (mean 5.3 +/- 3.9 hrs vs 5.5 +/- 3.2 hrs), time to needle in hospital (25.6 +/- 11.2 min vs 26.3 +/- 6.2 min), site of infarct (anterior myocardial infarction 12 in group 1 vs 11 in group 2), relief of pain at 90 min (13 vs 12), more than 50 percent reduction of ST elevation at 90 minutes (17 vs 12) and left ventricular ejection fraction (48.8 +/- 9.1% vs 49.8 +/- 16.0%), respectively. Streptokinase was well tolerated in both the groups, although hypotension was more common with the accelerated regimen (5 in group 1 vs 3 in group 2; p = NS). Thus, 'accelerated' streptokinase given over 15 minutes in patients presenting within 12 hours of acute myocardial infarction is well tolerated and results in higher grades of TIMI flow in the infarct-related artery as compared to the "conventional" one-hour infusion regimen.

Safety and efficacy of abciximab use in conjunction with intracoronary urokinase in patients requiring angioplasty

Abciximab decreases ischemic complications during angioplasty. Intracoronary urokinase lyses intracoronary thrombus. We studied the combination of both drugs. Twenty-six consecutive patients with acute coronary syndromes and intracoronary thrombus underwent intervention with abciximab and intracoronary urokinase. All received aspirin and IV heparin. The dose of abciximab was a weight-adjusted bolus and a 12-hr infusion. The dose of urokinase was 250,000 to 633,000 units. Hemorrhagic complications were classified according to the TIMI study group. Hemoglobin and platelet counts were measured before and 12 and 48 hr after the procedure. Procedural success was achieved in 24 patients. There were no deaths or repeat interventions. No patient had a major bleeding complication. Only two had minor complications. One patient needed blood transfusion. None had a stroke or thrombocytopenia. The use of abciximab and intracoronary urokinase in the presence of intracoronary thrombus is associated with encouraging efficacy and few complications. Cathet. Cardiovasc. Intervent. 49:113-116, 2000.

Selective infusion of urokinase and thrombectomy in the treatment of acute cerebral sinus thrombosis

Acute cerebral sinus thrombosis caused a patient to decompensate rapidly and required immediate relief of her venous thrombosis as a life-saving procedure. The thrombus was laced with urokinase and removed from the sinuses with thrombectomy catheters. This reinstituted flow and she recovered full neurologic function within 4 hours.

Visual outcome after treatment with low-dose recombinant tissue plasminogen activator or hemodilution in ischemic central retinal vein occlusion

The ischemic type of central retinal vein occlusion (CRVO) is associated with a poor visual and ocular prognosis. Although several reports have indicated that hemodilution or thrombolytic therapy may be of benefit, there is still no consensus among ophthalmologists about the management of this disorder. In our study, we retrospectively evaluated the visual outcome after medical treatment in 58 patients with ischemic CRVO and severe visual loss (< or = 20/50). We separately investigated three different groups, depending on the following criteria: onset of symptoms within 11 days prior to admission and thrombolytic treatment with 50 mg of recombinant tissue plasminogen activator (rtPA) and intravenous heparinization (n = 23) or hemodilution therapy (n = 22) or onset of symptoms >11 days before the initial visit and hemodilution (n = 13). An advancement of 2 or more lines on the logarithmic visual acuity chart was noted in 10 cases (44%) in the rtPA group and in 3 subjects (14%) in the early-phase hemodilution group, whereas only 1 patient in the late-phase hemodilution group showed a comparable improvement. Our findings suggest that treatment with low-dose rtPA or hemodilution aimed at early restoration of blood flow has the potential to improve the visual prognosis in ischemic CRVO. The finding that thrombolysis had a favorable outcome supports the hypothesis that specific subgroups of patients may benefit from this therapeutic approach. Further investigation will be required to definitively prove the effectiveness of fibrinolytic agents.

Weekly prophylactic urokinase instillation in tunneled central venous access devices

PURPOSE

To determine the safety and efficacy of weekly prophylactic urokinase therapy in tunneled central venous access devices (VADs).

MATERIALS AND METHODS

A prospective, randomized study was performed in 105 patients who underwent tunneled VAD placement between March 1997 and April 1998. The patients were randomized to receive either twice-daily heparin flushes (14 heparin flushes per week; group A, n = 52) or twice-daily heparin flushes with once-weekly urokinase (UK) instillation (13 heparin flushes, one UK flush per week; group B, n = 53). Patients were followed up by examination and/or interview at 1, 3, and 6 months for signs and symptoms of delayed catheter-related complications.

RESULTS

The total number of indwelling catheter-days was similar between groups (5,450 in group A, 5,276 in group B). The total number of infectious complications and fibrin sheaths formed was greater for group A (n = 11; 21.1%) than group B (n = 3; 5.7%) (P = .02). There were no side effects noted from the prophylactic UK administrations.

CONCLUSION

Prophylactic UK is advantageous in preventing delayed catheter-related complications.

Multivariable analysis of predictive factors related to outcome at 6 months after intra-arterial thrombolysis for acute ischemic stroke

BACKGROUND AND PURPOSE

Recent reports have suggested that a rapid assessment of pretreatment residual cerebral blood flow (CBF) could be used to optimize selection criteria for thrombolysis in patients with acute ischemic stroke to improve clinical outcome. We investigated retrospectively residual CBF and other clinical factors related to outcome at 6 months after intra-arterial thrombolysis by using multivariable analysis.

METHODS

Seventy-six patients received intra-arterial thrombolysis within 6 hours of symptom onset. The multiple regression method was used to analyze associations between the modified Rankin scale (MRS) at 6 months after treatment and clinical factors including age, infarction type, duration of ischemia, dose of urokinase, degree of recanalization, hemorrhage, National Institutes of Health Stroke Scale score (NIHSSS), and residual CBF evaluated by pretreatment single-photon emission-computed tomography; these values were assessed with the use of the regional-to-cerebellar activity (R/CE) ratio of ischemic region to cerebellum and asymmetry index.

RESULTS

MRS at 6 months was good (0 to 3) in 65% and poor (4 to 6) in 35%. Factors significantly related to MRS at 6 months were R/CE ratio (P<0.0001), NIHSSS at baseline and the following day (P<0.0001), cardioembolic infarction (P=0.0014), age (P=0.0074), and recanalization grade (P=0. 007). NIHSSS of >20, R/CE ratio of <0.35, cardioembolic infarction, incomplete recanalization (grade <3), and older age (>75 years) were determined to be significant independent predictors of poor outcome.

CONCLUSIONS

The residual CBF, neurological score at baseline and the following day, age, and recanalization grade correlated significantly with long-term outcome. The NIHSSS of >20 and R/CE ratio of <0.35 were determined to be significant independent predictors of poor outcome by multivariable analysis.

Intraarterial catheter-directed thrombolysis: urokinase versus tissue plasminogen activator

The purpose of this study was to evaluate the differences between tissue plasminogen activator (TPA) and urokinase (UK) in the management of ischemic limbs. A total of 58 limbs (24 in the TPA group and 34 in the UK group) in 53 patients were studied prospectively. The two groups were based on the surgeon's preference for lytic agent. The dose regimen for UK was 150,000 IU/hr over 1/2 to 2 hr followed by a continuous infusion of 50,000 IU/hr. TPA was given as a 5-mg bolus followed by 1 mg/hr. Both groups received heparin at a rate of 400 IU/hr through the side arm of the arterial sheath. There was no significant difference in efficacy between UK and TPA, but TPA acted faster and had a higher incidence of bleeding complications.

Intraoperative intraarterial urokinase in early postoperative stroke following carotid endarterectomy: a useful adjunct

The purpose of this study was to determine the efficacy of intraoperative intraarterial urokinase (UK) in patients who suffered an acute stroke immediately following carotid endarterectomy (CEA). From January 1995 to March 1998, 823 carotid endarterectomies were performed. The subsequent results showed that intraarterial UK in the setting of early post-CEA neurologic events appears to be safe and may be a useful adjunct to re-exploration in improving neurologic outcomes.

Intra-arterial thrombolysis in a patient presenting with an ischemic stroke due to spontaneous internal carotid artery dissection

We describe a case of a 38-year-old male who presented with acute onset of right-sided hemiplegia and aphasia, who was transferred for emergent percutaneous intervention. Angiography revealed a dissection with total occlusion of the left internal carotid artery (ICA) with propagation of thrombus in the distribution of the middle cerebral artery (MCA). Therapy was directed at the MCA and not the ICA. Intra-arterial thrombolysis was performed on the M1 and M2 branches of the left middle cerebral artery, resulting in almost complete resolution of symptoms during the angiography procedure. Heparin was continued postprocedure, and the patient was discharged home on warfarin and aspirin with minimal residual symptoms.

Percutaneous transluminal angioplasty for intracranial atherosclerotic lesions: evolution of technique and short-term results

OBJECT

A retrospective analysis of a 9-year experience with balloon angioplasty for intracranial atherosclerotic stenosis was undertaken with the goals of illustrating development of a safe technique for treatment of intracranial atherosclerotic disease and reporting the immediate results in this series of patients.

METHODS

Three distinct periods are defined, based on the technique used. In the early period, in which eight patients were treated, the angioplasty balloon size approximated the vessel size, but was always smaller. Angioplasty was moderately rapid and brief (15-30 seconds). Clinical improvement occurred in seven (87.5%) of eight patients, dissection without consequence occurred in four (50%) of eight, and residual stenosis greater than 50% was found in three (37.5%) of eight. No neurological complications occurred. In the middle period, in which 12 patients were treated, the balloon size approximated the vessel size, but oversizing by up to 0.25 mm was permitted. Angioplasty was extremely rapid and brief. Angiographically visible dissection occurred in nine (75%) of 12 patients, necessitating urokinase infusion in five (41.7%) of 12 and producing abrupt occlusion in one (8.3%) of 12, resulting in death. Occlusion secondary to the recrossing of the lesion occurred in one (8.3%) of 12, resulting in stroke. Good outcome was eventually achieved in 10 (83.3%) of 12. In the current period, in which 50 patients have been treated, the balloon is always undersized and inflation is extremely slow (several minutes). Dissection occurred in seven (14%) of 50 patients, necessitating fibrinolysis in two of 50 (4%, both uneventful) and producing no abrupt occlusion or stroke. Residual stenosis greater than 50% occurred in eight (16%) of 50, with no stenosis greater than 70%. Late restenosis occurred in four (9%) of 44 and successful repeated angioplasty was performed in all four. One guidewire vessel perforation occurred (2%), resulting in the patient's death. Good angiographic and short-term clinical outcome was achieved in the other 49 patients (98%).

CONCLUSIONS

Extremely slow balloon inflation combined with balloon undersizing results in decreased intimal damage, decreased acute platelet/thrombus deposition, and decreased acute closure. This technique sometimes yields suboptimal angiographic results but achieves the clinical goal safely. Intracranial angioplasty can be safely performed using this technique and modern equipment.

Mesenteric and portal vein thrombosis in a young patient with protein S deficiency treated with urokinase via the superior mesenteric artery

A 32-year-old man, who was previously healthy, had acute abdominal pain without peritonitis. Diffuse mesenteric and portal vein thrombosis were shown by means of a computed tomography scan. A protein s deficiency was found by means of an extensive workup for hypercoagulable state. Successful treatment was achieved with urokinase infusion via the superior mesenteric artery without an operation. This represents an attractive alternative approach to treating patients with this disease. The previous standard of operative intervention(1) can now be reserved for complications, such as bowel infarction with peritonitis, or for those patients with absolute contraindications to thrombolytic therapy.

Local low-dose urokinase treatment of acquired intracardiac thrombi in preterm infants

We report three cases of intracardiac thrombi in preterm infants of very low birth weight, in whom local low-dose urokinase treatment achieved complete thrombolysis without any signs of systemic fibrinolytic activity or side-effects. This new treatment strategy seems to be safe, requires minimal monitoring of fibrinolytic activity, and may be a new option for thrombolysis in high-risk patients such as premature infants, patients recently operated on, and patients presenting with other contra-indications for systemic fibrinolytic therapy.

Intraarterial thrombolysis for treatment of acute stroke: experience in 26 patients with long-term follow-up

BACKGROUND AND PURPOSE

Since the approval of intravenous tissue plasminogen activator for acute ischemic stroke, great interest has been generated in cerebral fibrinolysis. Our purpose was to assess long-term outcome and hemorrhagic risk in patients with anterior circulation ischemic stroke treated with intraarterial urokinase.

METHODS

Twenty-six patients were treated within 6 hours of ictus; of these, 21 were followed up for an average of 23 months. Angiographic reperfusion was classified according to thrombolysis in myocardial infarction (TIMI) grades. The Rankin Scale (RS) and the modified Barthel Index (mod BI) were used as outcome measures (good outcome: RS = 0-2, mod BI = 16-20; poor outcome: RS = 3-5, mod BI < or = 15).

RESULTS

Ten of the 21 patients (average age, 48 years) had a good outcome; three (average age, 71 years) had a poor outcome; eight patients (average age, 78 years) died. Partial/complete (successful) recanalization was observed in 11 of 26 patients and minimal or no (unsuccessful) recanalization in 15. Recanalization favored a better outcome: nine of 21 had successful recanalization, with a good outcome in seven; 12 of 21 had unsuccessful reperfusion, with poor outcome/death in nine. Poor outcome was noted in five patients with internal carotid artery (ICA) bifurcation occlusions, four of whom had unsuccessful recanalization and poor outcome or death. Hemorrhage occurred in 10 of the 26 patients, with clinical deterioration in three. The average dose of urokinase was higher in the hemorrhage group, and mortality was higher in patients who hemorrhaged.

CONCLUSION

Intraarterial thrombolysis is feasible in the setting of acute stroke. Successful reperfusion is associated with a better outcome, and the prevalence of hemorrhage does not exceed that which occurs in the natural history of embolic stroke. Poor outcome or death is associated with nonrecanalization, older age, hemorrhage, and ICA bifurcation occlusions.

When is urokinase treatment an effective sole or adjunctive treatment for acute limb ischemia secondary to native artery occlusion?

BACKGROUND

Intra-arterial thrombolytic therapy is currently a therapeutic option for the treatment of acute limb ischemia. A recent large prospective randomized trial (TOPAS) comparing lytic therapy and operative intervention showed that both forms of treatment had similar results in terms of amputation-free survival. However, the exact role for lytic treatment is unclear.

METHOD

Over a 4-year period we treated 60 cases of acute limb ischemia in 57 patients secondary to native artery occlusion with thrombolytic therapy with urokinase. All patients were evaluated at 1 week, 1 month, and then at 3-month intervals posttreatment. Follow-up evaluations included pulse examination, pulse volume recordings, and duplex examinations to confirm arterial patency. No patients were lost to follow-up with a range of 8 to 54 months (mean 26).

RESULTS

Of these 60 native arterial occlusions, complete lysis was achieved in 46 cases (76%). Of these 46 cases, 18 required lysis only, 19 cases (9 iliac, 7 superficial femoral artery (SFA), and 3 popliteal) required angioplasty of lesions uncovered by clot lysis, and 9 patients had lysis and angioplasty of iliac arteries followed by infrainguinal bypasses. Eight of the 57 patients (14%) who had been asymptomatic presented with symptoms limited to new onset claudication, all of which were successfully lysed. Cumulative patency for the 43 successful cases was 90% +/- 5% at 1 year and 75% +/- 4% at 2 years. The 1-year amputation-free survival for all native artery occlusions was 85% +/- 6%.

CONCLUSION

Thrombolysis with urokinase simplified the treatment of native arterial occlusion proving to be the sole therapy in 18 (29%) patients or a valuable adjunct by facilitating the angioplasty of arterial lesions and avoiding open surgery in 60% of patients treated. In addition, the correction of inflow lesions reduced the magnitude of required subsequent bypass procedures to achieve limb salvage. In conclusion, successful thrombolysis of native artery occlusion provided durable arterial patency and limb salvage, particularly in patients with new onset claudication.

Evaluation of reperfusion and recovery of brain function before and after intracarotid arterial urokinase therapy in acute cerebral infarction with brain SPECT

PURPOSE

Perfusion defects can be demonstrated reliably at an early stage with regional cerebral blood flow studies using SPECT. The administration of thrombolytic therapy in ischemic stroke is targeted at restoring cerebral perfusion immediately, leading to salvage of ischemic penumbra, smaller infarct size, and improved clinical outcome. This study considered the role of brain perfusion SPECT in the evaluation of reperfusion and brain function recovery of the infarcted area after early recanalization (less than 6 hours) of the occluded artery using intracarotid arterial urokinase therapy (ICAU).

METHODS

Intracranial artery occlusion was confirmed in seven patients using emergency carotid angiography performed within the initial 6-hour period. Intracarotid arterial urokinase (500,000 to 800,000 units) was administered into the occluded arterial system (the left middle cerebral artery in four and the right middle cerebral artery in three patients). CT scanning was performed when the patients arrived in the emergency department and was repeated 24 to 48 hours after ICAU and at 7 days or earlier if clinically indicated. All patients had two SPECT studies, the first before urokinase administration and the second 24 or 48 hours later.

RESULTS

Complete recanalization of the occluded vessels was seen in one patient after ICAU, effective partial recanalization was achieved in four patients, and minimal recanalization occurred in the other two. Before ICAU, Tc-99m HMPAO brain SPECT showed decreased uptake of the infarcted area in all patients, whereas the follow-up brain SPECT performed 24 or 48 hours after ICAU revealed improvement in the uptake of the recanalized area on qualitative and semiquantitative assessments using an asymmetry index, suggestive of brain function recovery and clinical improvement. Hemorrhagic transformation adjacent to the reperfused regions occurred in two patients with partial recanalization of the left middle cerebral artery.

CONCLUSIONS

Reperfusion of the recanalized area and brain function recovery could be achieved if the occluded artery is recanalized within the initial 6-hour period using ICAU, and this was documented using brain perfusion SPECT without a delay in the therapeutic time window. Because the number of patients we studied was limited, further study is necessary to evaluate the effect of ICAU and to determine its prognostic significance.

Intraarterial catheter thrombolytic therapy for acute peripheral arterial occlusions

Intraarterial thrombolytic therapy was performed in 36 patients with acute arterial occlusions of the extremities. Intraarterial thrombolytic therapy was effective in 19 of 24 patients (79.2%) with embolic occlusions. However, the results were poor in patients who had multiple arterial occlusions including those at sites other than the extremities. Only four of 12 patients (33.3%) with thrombotic occlusions had good initial technical results. Six patients died shortly after the thrombolytic procedure, and seven patients underwent amputation. The long-term patency rate of 21 patients who were treated successfully was 92.7% after one year and 74.6% after five years. Intraarterial catheter thrombolytic therapy was effective for embolic occlusion even when more than six hours had elapsed from the onset of symptoms. The indications for thrombotic occlusions may be limited, since associated marked atherosclerotic change was often present.