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Intracoronary urokinase in acute myocardial infarction: prevalence of total coronary occlusion during the early hours, effects on myocardial infarct size and left ventricular function, and outcome of residual coronary stenosis.

The effects of intracoronary thrombolysis (ICT) were studied in 88 acute myocardial infarction patients. Total coronary occlusion was observed in 67 of the 88 patients (76.1%) who were evaluated within 6 hours of the onset of symptoms. Among these 67 patients 42 (62.7%) were successfully recanalized by intracoronary urokinase. The recanalization rate was higher in the lesion at the left anterior descending artery, in younger patients (49 years or less) and in patients with a shorter history of pre-infarction angina. Eight of 11 patients (72.7%) with subtotal coronary occlusion and 17 of 35 patients (48.6%) with recanalization after ICT showed spontaneous regression of the residual coronary stenosis at the chronic stage angiography. There was no re-occlusion in the subtotal occlusion group and only 6 cases of re-occlusion (17.1%) in the recanalization group. The majority of re-occlusions progressed from the lesion with 99% residual stenosis and delayed filling. Accordingly the true value of additional percutaneous transluminal coronary angioplasty would be limited to the latter cases. Reduction in infarct size and improvement in left ventricular function were limited to those patients with incomplete or subtotal coronary occlusion and were not seen in cases with total obstruction which was recanalized by ICT.

Adult↗

Effects of percutaneous transluminal coronary angioplasty on segmental left ventricular function in patients with acute myocardial infarction.

In order to investigate the usefulness of percutaneous transluminal coronary angioplasty (PTCA) on subsequent left ventricular (LV) function in patients with acute myocardial infarction (AMI), regional ejection fraction (REF) was calculated from the left ventriculogram and compared in the acute and chronic phases (4 weeks after infarction) in 19 successful cases of PTCA (group A). In addition, 15 successful cases of intracoronary thrombolysis (PTCR) (group R) and 14 unsuccessful cases (group U) were also analyzed in this study. From the results, the following points were elucidated. (1) REF of group A in the chronic phase showed a significant increase compared to that in the acute phase (10 +/- 18% vs 20 +/- 19%, p less than 0.01), and this was similar to that observed in group R (9 +/- 19% vs 21 +/- 16%, p less than 0.01). (2) All cases in group A showed a significant increase in REF (p less than 0.02), if recanalization occurred within 3 hours after the onset of AMI. Some cases in the 3-6 hour recanalization group showed a decrease in REF. (3) In group A, only patients with subtotal occlusion on the initial coronary angiogram showed a significant increase in REF 4 weeks later (p less than 0.01), whereas patients with total occlusion on the initial coronary angiogram showed no significant increase in REF. (4) In group A, only patients recanalized between 3 and 6 hours showed a severe degree of prolonged contrast staining immediately after successful recanalization following PTCA. Thus, chronic phase regional wall motion was markedly improved by PTCA in those cases with residual flow. In contrast, abrupt recanalization after PTCA might causally decrease regional wall motion due to hemorrhagic infarction, if it is performed in cases with total occlusion.

Angioplasty, Balloon↗

Pulsed-spray thrombolysis of arterial and bypass graft occlusions.

Pulsed-spray thrombolysis is accomplished through forceful injection of a spray of highly concentrated urokinase into clot by using catheters with multiple side holes. We previously reported the immediate technical efficacy of the method in eight arterial and 10 bypass graft occlusions. We now describe the clinical efficacy of the method in a second, larger series of 23 native artery occlusions and 25 bypass graft occlusions. Transluminal angioplasty was performed after thrombolysis in 21 of the arteries and 24 of the bypass grafts. Initial thrombolysis was observed in all artery occlusions and all but one bypass graft occlusion with an average time for pulsed-spray lysis of 65 +/- 28 min in native arteries and 93 +/- 38 min in bypass grafts. Recanalization with improvement in symptoms or distal pulses after thrombolysis and angioplasty was achieved in 74% of treated arterial occlusions and 92% of treated graft occlusions. Of the 15 arteries that were recanalized and did not require adjunctive surgery, seven remained patent at 3-28 months follow-up. Nine of 23 recanalized bypass grafts required early adjunctive surgery. Of the nine synthetic and five saphenous vein grafts successfully recanalized and not requiring surgical revision, the mean patency was 4.3 +/- 3.1 months and 3.0 +/- 2.2 months, respectively. Minor complications were seen in 23% of cases. The two major complications (4%) involved one groin hematoma requiring surgery and one episode of gastrointestinal hemorrhage. We conclude that combined pulsed-spray thrombolysis and angioplasty achieve rapid and consistent arterial and graft recanalization with minimal risk. The method offers a favorable alternative to standard thrombolytic therapy of arterial occlusions. In occluded synthetic and vein bypass grafts, the technique is sometimes beneficial, either alone or combined with surgical revision.

Angioplasty, Balloon↗

Mechanical thrombolysis of acute occlusion of both the superficial and the deep femoral arteries using a thrombectomy device.

OBJECTIVE: Our objective was to evaluate the efficacy of the Amplatz thrombectomy device for recanalization of acute occlusions of both the superficial and the deep femoral arteries. MATERIALS AND METHODS: Eighteen patients with acute occlusions of the femoral arteries (eight male, 10 female; 10-87 years old) were treated using the Amplatz thrombectomy clot macerator. The duration of occlusion was 16 +/- 8 hr. Eighteen patients underwent treatment of the deep femoral artery, and 16 patients had additional involvement of the superficial femoral artery. After primary recanalization of the deep femoral artery, the superficial femoral artery was also recanalized using the Amplatz thrombectomy device. Nine patients required additional aspiration thrombectomy of the tibial arteries, five patients required additional aspiration thrombectomy of side branches of the deep femoral artery, and 12 patients required additional local thrombolysis with urokinase. RESULTS: In 14 (78%) of 18 patients, recanalization of the deep femoral artery was complete without demonstrable residual thrombi. Arterial spasms were observed in five patients (28%). The rate of limb salvage was 94% at a mean follow-up interval of 8.9 +/- 4.1 months. In the 18 patients, the ankle-brachial pressure index went from a median value of 0.56 before therapy to a median value of 0.91 after therapy. No severe complications occurred. CONCLUSION: Mechanical thrombolysis in the deep femoral artery with the Amplatz thrombectomy device is an effective, rapid method of treatment and is rarely associated with complications. In cases of concomitant occlusion of the tibial arteries, recanalization should always be attempted because the deep femoral artery may provide a functionally decisive collateral artery between the iliac and tibial vasculature.

Adolescent↗

Reduction of infarct volume by thrombolysis with rt-PA in an embolic rat stroke model.

Thrombolytic therapy with recombinant tissue plasminogen activator was tested in an embolic stroke model. In rats the internal carotid territory was embolized through the internal carotid artery with 50 microliters thrombin-rich (n = 18), 50 microliters thrombin-poor (n = 17) and 20 microliters thrombin poor (n = 13) suspension of arterial-like microthrombi formed under pressure. Hemispheric cerebral blood flow before and after embolization was measured by intra-arterial 133Xe injection method. Fifteen minutes after embolization 19 animals were treated with tissue plasminogen activator 20 mg kg-1, and 22 animals with saline. Carotid angiography displayed the degree of occlusion of the cerebral arterial supply before and after treatment. Brains were evaluated neuropathologically and infarct volume measured. Cerebral blood flow was reduced 72% after embolization with 50 microliters emboli suspension and 32% after embolization with 20 microliters suspension. The comparison of pre- and post-treatment angiography showed some recanalization in the treated animals, control animals had no recanalization. Thrombolytic therapy reduced the infarct volume from 72.8% to 20.9% of embolized hemisphere volume (p = 0.0037) in the 50-microliters thrombin rich-embolized group, from 22.9 to 9.0 (NS) in the 50-microliters-thrombin-poor-embolized group and from 6.6 to 0.0 (NS) in the 20-microliters-embolized group. One third of treated animals recanalized completely and developed smaller (p = 0.03) infarcts than the non-recanalized. No hemorrhagic complications were observed. Early thrombolytic therapy reduced infarct volume after embolic stroke in this model, this effect was dependent upon recanalization.

Animals↗

Intra-arterial thrombolysis in acute basilar artery thromboembolism: the initial Mayo Clinic experience.

OBJECTIVE: To investigate the feasibility of intra-arterial thrombolysis in acute basilar artery thrombosis. DESIGN: We reviewed a consecutive series of patients in whom intra-arterial thrombolysis was performed during the period from 1994 to 1996. MATERIAL AND METHODS: Intra-arterial thrombolysis with urokinase was done in an attempt to recanalize the basilar artery in a series of nine patients with basilar artery thrombosis admitted to the neurologic intensive care unit. At the time of initial assessment, all nine patients had major neurologic deficits attributable to brain-stem ischemia, including two patients with locked-in syndrome. RESULTS: Recanalization of the basilar artery system was successful in seven of the nine patients (a range of 2 to 13 hours after the ictus). Failure to recanalize the basilar artery occurred in two patients, who died after progressing to coma. Complete recovery or only minimal neurologic deficits were demonstrated in five of the nine patients. Despite recanalization of the basilar artery, two patients had no major change in their neurologic function, and both ultimately had severe ataxia and were fully dependent on others. A cerebellar hemorrhage occurred in one patient but without clinical worsening. Two patients had a retroperitoneal hematoma. CONCLUSION: Intra-arterial thrombolysis with urokinase in acute basilar artery occlusion resulted in recanalization in seven of the nine patients (78%). Five of the nine patients recovered fully, including two patients who had had locked-in syndrome. In light of the devastating natural course of acute basilar artery occlusion, these initial results are encouraging and indicate that intra-arterial thrombolysis may be a useful emergency treatment, even in patients with prolonged symptoms of ischemia (up to 12 hours).

Adult↗

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.

Acute Disease↗

Evaluation of the stability of aneurysms after embolization using detachable coils: correlation between stability of aneurysms and embolized volume of aneurysms.

BACKGROUND AND PURPOSE: The long-term outcome of aneurysmal coil embolization has not been determined. We retrospectively analyzed the results of our cases treated with detachable coils and evaluated the long-term stability of embolized aneurysms. METHODS: This study involved 100 aneurysms in 93 patients who underwent follow-up angiography > or = 3 months after initial treatment between December 1993 and December 1999. The percentage of the coil volume occupying the aneurysm lumen (embolized volume) was used as an index to evaluate the stability of embolized aneurysms. The reliability of the embolized volume was also evaluated by comparing angiographic percentage occlusion. RESULTS: Follow-up angiographic assessment was conducted 12 +/- 8.5 months after initial treatment. Angiographic evaluation of percentage occlusion at initial treatment did not always predict long-term stability of embolized aneurysms. Of 49 aneurysms judged as being totally occluded at initial treatment, 44 remained unchanged and five showed recanalization. The embolized volume of unchanged aneurysms was 30.8 +/- 10.2%, and that of recanalized aneurysms was 19.9 +/- 10.6%. There was a significant difference between these two groups (P=.03). Of 29 subtotally occluded aneurysms, nine had further thrombosis (embolized volume = 31.8 +/- 12.7%), nine remained unchanged (embolized volume = 23.2 +/- 10.3%), and 11 had recanalization (embolized volume = 14.1 +/- 6.1%). The mean embolized volume of 11 recanalized aneurysms was significantly lower than in the thrombosed group and the unchanged group (P=.002 and P <.001, respectively). Large aneurysms tended to have recanalization more frequently (59%) than did small aneurysms (15%). CONCLUSION: There is a significant correlation between embolized volume and stability of embolized aneurysms. Embolized volume is a more objective index than is subjectively angiographic percentage occlusion. In addition to angiographic assessment, measurement of embolized volume could be useful to predict angiographic changes of aneurysms.

Adult↗

Ultrasound-enhanced thrombolysis for acute ischemic stroke: phase I. Findings of the CLOTBUST trial.

BACKGROUND: Tissue plasminogen activator (TPA) activity may be enhanced with ultrasound, potentially 2 MHz transcranial Doppler (TCD). The authors present Phase I data of the CLOTBUST (Combined Lysis of Thrombus in Brain ischemia using transcranial Ultrasound and Systemic TPA). SUBJECTS AND METHODS: Nonrandomized stroke patients with proximal arterial occlusion on a prebolus TCD receiving intravenous 0.9 mg/kg TPA within 3 hours after stroke onset were monitored with portable diagnostic TCD equipment and a standard headframe. Complete recanalization was defined as thrombolysis in brain ischemia (TIBI) flow grades 4-5. RESULTS: 55 patients (mean age 69 +/- 15 years, median baseline NIH Stroke Scale [NIHSS] 18, range 4-29, 90% with 3 9 points) were treated at 125 +/- 36 minutes from symptom onset. TCD monitoring began at 117 +/- 39 minutes. Complete recanalization on TCD within 2 hours after bolus was found in 20 patients (36%). Dramatic recovery (NIHSS score < or = 3) occurred in 20% at 2 hours and in 24% at 24 hours. Overall improvement by > or = 4 NIHSS points was found in 49% at 24 hours. Improvement was associated with recanalization during or shortly after TPA infusion (phi r2 = .5, P = .03); however, in 6/20 patients with complete recanalization (30%), no immediate clinical change was noticed within 2 hours. Overall symptomatic hemorrhage rate was 5.5%. CONCLUSIONS: Continuous TCD insonation for up to 2 hours at maximum intensities allowed by current bio-safety guidelines is safe. Dramatic recovery and complete recanalization shortly after TPA bolus are feasible goals for thrombolysis given with TCD monitoring.

Aged↗

Angiographic assessment of pial collaterals as a prognostic indicator following intra-arterial thrombolysis for acute ischemic stroke.

BACKGROUND AND PURPOSE: This study examines whether anatomic extent of pial collateral formation documented on angiography during acute thromboembolic stroke predicts clinical outcome and infarct volume following intra-arterial thrombolysis, compared with other predictive factors. METHODS: Angiograms, CT scans, and clinical information were retrospectively reviewed in 65 consecutive patients who underwent thrombolysis for acute ischemic stroke. Clinical data included age, sex, time to treatment, National Institutes of Health Stroke Scale (NIHSS) score on presentation of symptoms, NIHSS score at the time of hospital discharge, and modified Rankin scale score at time of hospital discharge. Site of occlusion, scoring of anatomic extent of pial collaterals before thrombolysis, and recanalization (complete, partial, or no recanalization) were determined on angiography. Infarct volume was measured on CT scans performed 24-48 hours after treatment. RESULTS: Fifty-three patients (82%) qualified for review. Both infarct volume and discharge modified Rankin scale scores were significantly lower for patients with better pial collateral scores than those with worse pial collateral scores, regardless of whether they had complete (P < .0001) or partial (P = .0095) recanalization. Adjusting for other factors, regression analysis models indicate that the infarct volume was significantly larger (P < .0001) and modified discharge Rankin scale score and discharge NIHSS score significantly higher for patients with worse pial collateral scores. Similarly, adjusting for other factors, the infarct volume was significantly lower (P = .0006) for patients with complete recanalization than patients with partial or no recanalization. CONCLUSIONS: Evaluation of pial collateral formation before thrombolytic treatment can predict infarct volume and clinical outcome for patients with acute stroke undergoing thrombolysis independent of other predictive factors. Thrombolytic treatment appears to have a greater clinical impact in those patients with better pial collateral formation.

Adult↗

[Platelet activation during thrombolysis and percutaneous transluminal coronary angioplasty in the acute phase of myocardial infarction].

To clarify the mechanism of recanalization and reocclusion in thrombolysis and percutaneous transluminal coronary angioplasty (PTCA), the plasma concentrations of beta-thromboglobulin (beta-TG), thromboxane B2 (TXB2) and platelet aggregation adenosine diphosphate (ADP) (2 microM/ml, collagen 2 micrograms/ml) were assessed in 11 normal subjects and in 19 patients with acute myocardial infarction whose infarct-related vessels were recanalized by thrombolysis and/or PTCA. In patients with acute myocardial infarction, the plasma concentrations of beta-TG and TXB2 were significantly higher than those in normal subjects (beta-TG: 128 +/- 132 ng/ml vs 38 +/- 17 ng/ml, TXB2: 131 +/- 154 pg/ml vs 36 +/- 18 pg/ml). Collagen-induced platelet aggregation decreased significantly in patients with acute myocardial infarction; whereas, ADP-induced platelet aggregation showed no significant difference. Infarct-related vessels recanalized by thrombolysis (seven patients: group 1) and PTCA (seven patients: group 2) were patent on the follow-up angiograms. Infarct-related vessels were reoccluded in five patients immediately after PTCA or during the follow-up angiography (group 3). Beta-TG and TXB2 did not change before and after recanalization in groups 1 and 2, but increased significantly after recanalization in group 3 (beta-TG: 155 +/- 185 ng/ml----269 +/- 233 ng/ml, TXB2: 104 +/- 87 pg/ml----169 +/- 91 pg/ml). Platelet aggregation did not differ significantly among the three groups. We concluded that platelets are not activated during thrombolysis and/or PTCA in cases without reocclusion, while platelets are markedly activated during PTCA in cases with reocclusion. Thus, it is suggested that platelet activation plays an important role in the mechanism of reocclusion.

Adenosine Diphosphate↗

[Various aspects of organogenesis of the colon in Gallus domesticus: morphologic observation].

The authors have investigated the morphological aspects of the wall components of the developing colon in the chick embryo (Gallus domesticus) from the 7th to th 15th day of incubation. Particular attention has been given to the lumen recanalization, phenomenon which occurs also in other animal species. The most significant results can be summarized as follows: 1) the lumen is recanalized at the 7th day only at the proximal part of the colon (Fig. 1, Tav. 1), while at the distal tract it is still completely filled by an epithelial plug (Fig. 2, Tav. 1). Therefore the recanalization of the lumen takes place cranio-caudad. 2) At the 8th day the process of recanalization of the lumen shows, in the distal part of the colon, well defined modalities. Radially oriented intraepithelial spaces within the epithelium filling the lumen join other semilunar intercellular spaces, which are placed near the central part of the occluded lumen (Fig. 3). By the junction of a couple of radially oriented spaces with one semilunar space, an U-shaped intercellular space derives, which delimits an incoming epithelial fold (Tav. 3). Such a phenomenon is continued also during the 9th and 10th day of incubation (Fig. 6, Tav. 2). 3) At the 11th day the colonic lumen is completely open and, in its distal part, the appearance of the primordial previllous ridges can be observed (Fig. 7). In the proximal tract the previllous ridges develop one day later (Fig. 8). 4) At the 13th day, in the distal part of the colon, the first appearance of crypts occurs (Fig. 10). So, while the process of recanalization of the lumen is cranio-caudad, the formation of previllous ridges and crypts proceeds caudo-cranially. 5) From the 11th day onwards the lamina propria is actively involved in the process of formation of the previllous ridges. Only at the 14th day, in the distal part of the colon anlage, the appearance of the muscularis mucosae is observed (Fig. 11). 6) The muscle layer and the subserous stratum do not show appreciable morphological changes in the course the considered period of incubation.

Animals↗

[The significance of early coronary reperfusion in patients with acute myocardial infarction assessed by regional wall motion].

Left ventricular ejection fraction, regional wall motion, hospital mortality rate, and reocclusion rate of the infarct-related coronary artery after thrombolytic therapy were examined in 164 consecutive patients who were admitted within 12 hours of the onsets of their symptoms of acute myocardial infarction. The patients were divided into three groups based on the findings of initial coronary angiography before and after administration of urokinase: (1) stenosed (the infarct-related coronary blood flow was visualized at initial angiography) (n = 41); (2) successfully thrombolysed (n = 82); and (3) unsuccessful (n = 41). The patients in each group were also subdivided into three subgroups based on the recanalized time (hours): within three, three to six hours and six hours or longer. The hospital mortality rates were 4.9% (two of the 41 patients) in the stenosed; 8.5% (seven of the 82 patients) in the thrombolysed; 29.3% (12 of the 41 patients) in the unsuccessful group, and 12.8% (21 of the 164 patients) overall, respectively. There were significant differences among these three groups. The incidence of pump failure as a cause of death in the acute stage was significantly low in the stenosed (two of the 41 patients) and in the thrombolysed (3 of the 82 patients) groups compared to the unsuccessful group (eight of the 41 patients). The rates of rethrombosis one month after thrombolytic treatment were 3% in the stenosed and 4% in the thrombolysed groups. On the contrary, visualization of coronary blood flow at the chronic stage (approximately one month later) was confirmed in 19% of the patients in the unsuccessful group. Left ventricular ejection fraction one month after thrombolytic therapy in the subgroup with the recanalized coronary arteries within three hours was significantly higher than that of the unsuccessful group, but, after three hours of procedure, no significant difference of left ventricular ejection fraction was present among three groups. Regional wall motion in patients with the recanalized coronary artery within 12 hours was better than that of the unsuccessful group. The area of improved wall motion was wide in patients with early recanalization in the stenosed and thrombolysed groups. Thus, early recanalization within three hours is mandatory for reducing mortality and for improving ejection fraction and wall motion.

Humans↗

Comparison of the thrombolytic efficacy of defibrase and urokinase on canine coronary artery thrombosis and the mechanism of urokinase-induced hemorrhage.

The thrombolytic efficacy of defibrase (DF) and urokinase (UK) was evaluated and compared in a canine model in which left circumflex coronary artery (LCX) thrombus formation was initiated by electrical stimulation (150 UA, DC) of the arterial intimal surface via an implanted copper wire electrode. Forty-eight mongrel dogs were equally divided into 8 groups: six groups for both intravenous (iv) and intracoronary (ic) infusion of DF, UK and normal saline 30 min after complete obstruction by a LCX thrombus, the remaining two groups for iv infusion DF and UK 360 min after occlusion. Results showed that in the control groups no LCX recanalization after infusion occurred, but all the treated groups recanalized when drug infusion started 30 min after occlusion. Thrombus wet weight and infarct size were much higher in the control group. No significant differences were found between treated groups except that the recanalizing speed was fastest by ic UK with the highest occurrence rate of reperfusion arrhythmia. For 6-hour-old thrombi, DF was more effective than UK for recanalization. Thrombus wet weight and infarct size were lower in the recanalized dogs. Both agents reduced plasma plasminogen and fibrinogen significantly but serious incision bleeding was only found in the UK group. In order to study the mechanism underlying UK-induced hemorrhage, we observed the influences of UK and DF on blood coagulation factors in another 12 dogs. Results showed that DF only reduced factor 1 while UK additionally reduced coagulation factors 2, 7, 8 and 10, indicating that the non-selective depletive effect on coagulation factors may be one of the mechanisms of UK-induced hemorrhage. We conclude that both DF and UK can lyse fresh coronary thrombi, DF was more effective than UK on lysing older thrombi, considering its convenient use and less frequency of side effects, DF is therefore considered a more promising agent clinically.

Animals↗

Angioscopy as an adjunct to arterial reconstructive surgery: a preliminary report.

To date our use of angioscopy as an adjunct to in situ vein grafting, arterial embolectomy, femoropopliteal bypass surgery, and laser recanalization has been studied in 11 patients. Three angioscopes have been used: a 1.7 mm optiscope, a 2.8 mm laser optiscope, and a 3.2 mm bronchoscope. Scopes were introduced through an arteriotomy and a clear field maintained by continuous saline infusion. Twenty-four angioscopic evaluations were performed in the 14 patients studied. Adequate visualization was achieved with all three scopes. Angioscopy showed total atherosclerotic occlusion of six superficial femoral and popliteal arteries, intimal flaps in two arteries, thrombus in two arteries and one graft, adequate valvulotomy in three saphenous veins used for in situ bypass grafting, and removal of thrombus after embolectomy in one artery. With the 2.8 mm laser optiscope, the optical fiber used for laser recanalization could be positioned at the site of arterial occlusion before lasing and recanalization were done under direct vision. The 1.7 mm scope could be passed through the recanalized artery to inspect the channel and confirm communication with the artery distal to the occlusion. Thus, angioscopy appears to be potentially useful as a diagnostic device in arterial occlusive disease and as an adjunct in in situ saphenous vein grafting or laser recanalization of occluded arterial segments.

Arterial Occlusive Diseases↗

[Dynamic pathophysiology of cerebral infarction and revascularization. I. Ischemic cerebral edema].

A natural history of ischemic cerebral edema was analyzed in 100 patients with occlusive cerebrovascular diseases admitted within one week of onset, with serial computed tomography (CT) and angiograms. Cerebral edema was defined as a low-density area with mass sign on CT. A total of 446 studies of CT were performed. In 40 patients with major completed stroke admitted 24 hours of onset, a total of 73 studies of CT were taken within 48 hours of onset, and a timing of appearance of cerebral edema was analyzed. Patients were allocated to two groups according to the findings on angiograms; 68 patients who showed occlusive lesions on sequential angiograms (the group of no-recanalization), and 32 patients who showed reopening of occluded vessels on the first or sequential angiograms (the group of no-recanalization). In the group of no-recanalization a low-density area gradually appeared between 6 and 24 hours of onset A. mass sign reached its peak on the 3rd day with a peak incidence of 56%, and midline shift was present in 30% of the cases. It was resolved within 2 weeks in most cases. In the group of recanalization, a low density area appeared after 4 hours and rapidly increase after 6 hours. All patients had a low-density area at 12 hours of onset. A mass sign progressed until the 6th day with a peak incidence of 82%, and midline shift was present in 50% of the cases. The duration of mass sign was longer than that in the group of no-recanalization. These results suggest that the permissible duration of ischemia is considered to be within 6 hours of onset in profound ischemia. After 6 hours, ischemic tissue damage may not be reversible by the revascularization, even if CT shows no change during ischemia. An abrupt revascularization may not contribute to the recovery of brain damage, but accelerate the ischemic cerebral edema.

Aged↗

Argatroban tPA stroke study: study design and results in the first treated cohort.

BACKGROUND: The benefit of intravenous recombinant tissue plasminogen activator (rtPA) in acute stroke is linked to clot lysis and artery recanalization. Argatroban is a direct thrombin inhibitor that safely augments the benefit of rtPA in animal stroke models. There are no human data on this combination. DESIGN: We report the first phase of the Argatroban tPA Stroke Study, an ongoing prospective, open-label, dose-escalation, safety and activity study of argatroban and rtPA in patients with ischemic stroke. The primary outcome was incidence of intracerebral hemorrhage; secondary outcome, complete recanalization at 2 hours. After standard-dose intravenous rtPA administration, a 100-mug/kg bolus of argatroban followed by infusion of 1 mug/kg per minute for 48 hours was adjusted to a target partial thromboplastin time of 1.75 times that of the control group. RESULTS: Fifteen patients (including 10 men) were enrolled, with a mean +/- SD age of 61 +/- 13 years. All patients had middle cerebral artery occlusions. Baseline median National Institute of Health Stroke Scale score was 14 (range, 4-25). The mean +/- SD time from symptom onset to argatroban bolus administration was 172 +/- 53 minutes. Symptomatic intracerebral hemorrhage occurred in 2 patients, including 1 with parenchymal hemorrhage type 2. Asymptomatic bleeding occurred in 1 patient and there was 1 death. Recanalization was complete in 6 patients and partial in another 4, and reocclusion occurred in 3 within 2 hours of rtPA bolus administration. CONCLUSION: The safety of low-dose argatroban combined with intravenous rtPA may be within acceptable limits, and its efficacy for producing fast and complete recanalization is promising, but a larger cohort of patients is required to confirm these preliminary observations.

Adolescent↗

Laser angioplasty with a pulsed NdYAG laser: early clinical experience.

Since December 1986, 40 laser angioplasty procedures have been performed using the energy from a pulsed NdYAG laser, delivering near infrared light (1064 nm) in 100-microseconds pulses of approximately 300 mJ per pulse, directly through a transparent sapphire tipped device. All patients had total occlusion of the superficial femoral artery and symptoms severe enough to warrant surgery, with ulceration or gangrene in eight, rest pain in 14 and severe claudication interfering with life-style in the others. The device was introduced through an antegrade puncture of the superficial or common femoral artery and laser recanalization was followed by attempted balloon angioplasty in all cases. Occlusions were a median length of 15 cm (range 2-35 cm); ten patients had previously undergone failed attempts at conventional balloon angioplasty and four had occluded femoropopliteal grafts. Thirty-seven legs of 34 patients were treated with an average of 60 J (range 10-235 J) with successful recanalization in 27 and immediate reocclusion in seven. The 20 successful recanalizations have been followed up for up to 24 months (median 7 months) with only one late occlusion at 5 months. Failed recanalization was due to poor transmission by the delivery device in the early part of the series (five cases), repeated passage of the device down a collateral branch (four cases), dissection at the site of previous surgery (two cases) or no apparent reason (two cases). Immediate reocclusion was due to very poor run off in patients with severely ischaemic limbs (three cases) or technical difficulties with balloon dilatation (two cases). Complete symptomatic relief was obtained in all the cases of radiologically successful laser angioplasty. Early surgery was required in one case following reocclusion of the artery when an angioplasty balloon failed to deflate, and one patient suffered a skin reaction thought to be due to inadequate removal of the sterilizing solution. A different sterilizing procedure is now followed. Laser angioplasty can reduce the number of patients requiring bypass surgery and improvements in the device and access methods may reduce the number of untreatable cases.

Adult↗