Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Recanalization”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,225 records · Page 68Linked to original sources
PubMed1991

Results and follow-up after percutaneous pulsed laser-assisted balloon angioplasty guided by spectroscopy.

BACKGROUND: Few data are available on the long-term outcome of patients who undergo laser-assisted balloon angioplasty for recanalization of occluded peripheral arteries. Because the cost of laser angioplasty is high, the value of the method should be carefully analyzed before it can be considered a routine method for recanalization. The purpose of this study was to evaluate the early and late results of laser-assisted balloon angioplasty in patients who could not be recanalized by conventional techniques. METHODS AND RESULTS: Laser angioplasty was performed in 66 patients with total occlusion of the iliofemoral artery in whom mechanical techniques failed to recanalize the obstructed vessel. The system consisted of a pulsed dye laser operated at 480 nm, 2 microseconds/pulse, 5 Hz, 50 mJ/pulse coupled into a 0.021-in. laser catheter. The treatment laser was connected with a diagnostic laser to induce tissue fluorescence for spectroscopic analysis via the same fiber. The treatment laser was emitted only when atheromatous tissue was recognized. After a pilot hole was created by laser emission, dilatation was performed to enlarge the channel. The mean length of occlusion was 8.8 +/- 6.1 cm. The primary success rate was 82%. It did not depend on the length of occlusion but was greater in non-calcified than in calcified lesions (88% versus 71%, p less than 0.03). Complications included seven early reocclusions that could be recanalized and eight perforations without clinical sequelae. At a mean 18-month follow-up, 64% of the laser-treated arteries remained patent. The rate of patency was related neither to the length of the occlusion nor to calcifications but was lower in patients who had early reocclusion (p less than 0.02). CONCLUSIONS: Pulsed dye laser-assisted balloon angioplasty is effective for recanalization of totally occluded arteries that cannot be treated by conventional means. The efficacy is limited by calcifications. The long-term patency rate is acceptable given the severity of the lesions.

Angioplasty, Laser↗
PubMed1991

Ultrasonic angioplasty in totally occluded peripheral arteries. Initial clinical, histological, and angiographic results.

BACKGROUND: Ultrasonic angioplasty was recently shown to ablate thrombi and atherosclerotic plaques in vitro and to recanalize occluded arteries in experimental animal models. The goal of the present study was to examine the clinical feasibility of ultrasonic angioplasty. METHODS AND RESULTS: Intraoperative ultrasonic angioplasty was performed in vivo on totally occluded peripheral arteries (n = 7). The ultrasonic angioplasty device consists of a 1.6-mm diameter flexible wire attached to a piezoelectric crystal generating ultrasound at 20 kHz. The controls, totally occluded human atherosclerotic femoral arterial segments (n = 6), were crossed mechanically with the ultrasound wire ex vivo but without application of ultrasonic energy. Ultrasonic angioplasty achieved successful recanalization without perforation in all vessels. Angiograms of the treated arteries showed an average lumen patency of 82.5%. Histological examination of the recanalized arteries revealed that the recanalization had taken place through intima diffusely involved with complicated plaque. The treated arteries, compared with the controls, had greater area of recanalized lumen (5.9 +/- 1.8 versus 1.7 +/- 0.4 mm2, p less than 0.05) and more flow (49.3 +/- 16.0 versus 11.8 +/- 4.9 ml/min, p less than 0.03). The damage in treated and control arteries was similar. Size-distribution analysis of the plaque debris from the treated arteries showed that 41 +/- 5% of the debris was 0.2-8 microns, 48 +/- 8% was 8-30 microns, and the remainder was 30-100 microns. In the mechanically crossed arteries, there was a shift in the distribution to larger size debris with 47 +/- 1% greater than 100 microns (p less than 0.001). CONCLUSIONS: Ultrasonic angioplasty may be a useful clinical method for recanalization of total occlusions in patients with peripheral vascular disease. Ultrasonic energy appears to cause controlled injury to the atherosclerotic intima by selectively disrupting the ultrasound-sensitive occlusion.

Aged↗
PubMed1995

New variant of human tissue plasminogen activator (TPA) with enhanced efficacy and lower incidence of bleeding compared with recombinant human TPA.

BACKGROUND: The thrombolytic properties of a new variant of tissue plasminogen activator (TPA) (T103N, N117Q, KHRR 296-299 AAAA, or TNK-TPA) with longer plasma half-life, greater fibrin specificity, and increased resistance to inhibition by plasminogen activator inhibitor (PAI-1) were investigated in a rabbit thrombosed carotid artery model. METHODS AND RESULTS: After 60 minutes of arterial occlusion, TPA (1.5, 3.0, 6.0, or 9.0 mg/kg as a front-loaded IV infusion for 90 minutes; n = 22) or TNK-TPA (0.38, 0.75, or 1.5 mg/kg as IV bolus; n = 16) was administered. Blood flow through the artery was monitored for an additional 120 minutes. Bleeding was assessed by weighing the amount of blood absorbed in a gauze pad placed in a subcutaneous muscular incision. Recanalization rates and duration of recanalization were dose dependent. The doses that produced > 80% recanalization rates with the longest duration of recanalization were 9.0 mg/kg for TPA and 1.5 mg/kg for TNK-TPA. At these doses, time to reperfusion (mean +/- SEM) was significantly faster (11 +/- 2 versus 23 +/- 7 minutes) and duration of recanalization longer (77 +/- 9 versus 51 +/- 18 minutes) for TNK-TPA compared with TPA (P < .025). Weights of the residual thrombi of the TPA group were greater than those of the TNK-TPA group (P = .004). Concentrations of fibrinogen, plasminogen, and alpha 2-antiplasmin at 120 minutes were significantly higher for TNK-TPA-treated animals compared with TPA-treated animals (P < .001). ANOVA of the blood loss data determined that there were significant differences between thrombolytic agents but not between doses. After correction for saline controls, total blood loss for pooled doses of TPA and TNK-TPA was 82 +/- 6 mg and 40 +/- 4 mg, respectively (P < .01). CONCLUSIONS: From these data, we conclude that TNK-TPA, given as a bolus, produces faster and more complete recanalization of occluded arteries in a rabbit experimental model compared with TPA, without increasing systemic plasmin generation or peripheral bleeding. In addition, we observed that TNK-TPA, unlike TPA, did not potentiate collagen-induced aggregation of platelets obtained from human plasma. This lack of effect on platelet aggregation by TNK-TPA potentially could be associated with a decreased risk of reocclusion after successful thrombolysis.

Animals↗
PubMed1995

Deleterious effects of a systemic lytic state on reperfused myocardium. Minimization of reperfusion injury and enhanced recovery of myocardial function by direct angioplasty.

BACKGROUND: The beneficial effects of flow restoration and the deleterious impact of reperfusion injury on ischemic myocardium are well known. However, most experimental studies have induced reperfusion by mechanical release of nonthrombotic occlusions, only occasionally in the presence of a systemic lytic state. Conditions differ markedly in patients undergoing pharmacological or mechanical recanalization of thrombotically occluded coronary arteries. Accordingly, this study was designed to determine whether the method of coronary occlusion and mode of recanalization influence the response of the heart to reperfusion. METHODS AND RESULTS: The acute effects of reperfusion on right ventricular (RV) function and histology were studied in open-chest dogs subjected to right coronary artery (RCA) balloon occlusion and deflation alone (group 1), pharmacological lysis of thrombotic occlusions (group 2), balloon occlusion with reperfusion induced by balloon deflation in the presence of a systemic lytic state (group 3), and recanalization of thrombotically occluded vessels by direct angioplasty (group 4). In all groups, 1 hour of RCA occlusion led to RV free wall (FW) dyskinesis. In group 1, reperfusion promptly improved RVFW function, with normal RVFW thickness and only minimal edema by microscopy. In contrast, in group 2, clot lysis led to acute RVFW swelling and impaired recovery of RVFW contraction associated with striking interstitial edema, contraction band necrosis, and hemorrhage by microscopy. In group 3, balloon deflation in the presence of a lytic state led to a similar but less severe pattern of abrupt RVFW swelling and impaired recovery of RVFW function but lesser histological alterations than in group 2. However, mechanical recanalization of thrombotically occluded vessels (group 4) led to prompt recovery of RVFW function without significant RVFW swelling or histological abnormalities. CONCLUSIONS: Our observations indicate that the responses of ischemic myocardium to reperfusion are influenced by factors beyond those effects attributable to ischemia and reperfusion per se. Pharmacological lysis of coronary thrombi results in alterations characteristic of reperfusion injury and associated with impaired functional recovery. Such changes are also evident, although to a lesser extent, when reperfusion of northrombotic occlusions is induced by mechanical recanalization in the presence of a systemic lytic state but not in its absence. However, such effects were not seen with direct mechanical recanalization of thrombotically occluded vessels. In aggregate, these findings indicate that induction of a systemic lytic state, together with products released by lysis of intracoronary thrombi, generates an inurious milieu that exerts adverse effects on reperfused myocardium.

Angioplasty, Balloon, Coronary↗
PubMed2002

Thrombolysis-related hemorrhagic infarction: a marker of early reperfusion, reduced infarct size, and improved outcome in patients with proximal middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: The role of early and delayed recanalization after thrombolysis in the development of hemorrhagic transformation (HT) subtypes remains uncertain. We sought to explore the association between the timing of recanalization and HT risk in patients with proximal middle cerebral artery (MCA) occlusion treated with intravenous recombinant tissue plasminogen activator (rtPA) <3 hours of stroke onset and to investigate the relationship between HT subtypes, infarct volume, and outcome. METHODS: Thirty-two patients with acute stroke caused by proximal MCA occlusion treated with rtPA <3 hours of symptom onset were prospectively studied. Serial transcranial Doppler examinations were performed on admission and at 6, 12, 24, and 48 hours. Presence and type of HT were assessed on CT at 36 to 48 hours. Modified Rankin scale was used to assess outcome at 3 months. RESULTS: Early and delayed recanalization was identified in 17 patients (53.1%) and 8 patients (25%), respectively. HT was detected in 14 patients (43.7%): 4 (12.5%) with hemorrhagic infarction (HI1), 5 (15.6%) with HI2, 3 (9.3%) with parenchymal hematoma (PH1), and 2 (6.8%) with PH2. Distribution of HT subtypes differed significantly (P=0.025), depending on the time to artery reopening. Eight of 9 (89%), 1 of 5 (20%), and 8 of 18 (44.4%) with HI1-HI2, with PH1-PH2, and without HT, respectively, recanalized in <6 hours. Delayed recanalization was observed in 1 patient with HI1-HI2 (11%), 4 with PH1-PH2 (80%), and 3 without HT (16.6%). Neurological improvement was significantly (P<0.001) more frequent in patients with HI1-HI2 (88%) than in those without HT (39%). Infarct volume was significantly (P<0.031) lower in patients with HI1-HI2 (51.4+/-42 cm3) than in patients with PH1-PH2 (83.8+/-48 cm3) and those without HT (98.4+/-84 cm3, P=0.021). The modified Rankin scale score was significantly lower in HI1-HI2 compared with PH1-PH2 patients (1.9+/-1.1 versus 4.6+/-1.2, P<0.001) and with those without HT (1.9+/-1.1 versus 3.5+/-2.0, P=0.009.). CONCLUSIONS: Thrombolysis-related HI (HI1-HI2) represents a marker of early successful recanalization, which leads to a reduced infarct size and improved clinical outcome.

Adult↗
PubMed2005

Microbubble administration accelerates clot lysis during continuous 2-MHz ultrasound monitoring in stroke patients treated with intravenous tissue plasminogen activator.

BACKGROUND AND PURPOSE: We sought to evaluate the effects of administration of microbubbles (MBs) on the beginning, speed, and degree of middle cerebral artery (MCA) recanalization during systemic thrombolysis and continuous 2-MHz pulsed-wave transcranial Doppler (TCD) monitoring. METHODS: We evaluated 111 patients with acute stroke attributable to MCA occlusion treated with intravenous tissue plasminogen activator (tPA). Thirty-eight patients were treated with tPA plus continuous 2-hour TCD monitoring plus 3 doses of 2.5 g (400 mg/mL) of galactose-based MBs given at 2, 20, and 40 minutes after tPA bolus (MB group). These patients were compared with 73 patients who were allocated to receive tPA plus continuous 2-hour TCD ultrasound (US) monitoring (tPA/US group) or tPA plus placebo monitoring (tPA group), most of whom were enrolled in a previous study of US-enhanced thrombolysis. The beginning, degree, and time to maximum completeness of recanalization during the first 2 hours of tPA bolus were recorded. RESULTS: Median prebolus National Institutes of Health Stroke Scale (NIHSS) score was 18. Eighty patients (72%) had a proximal and 31 (28%) a distal MCA occlusion on TCD. Thirty-seven patients (33%) received tPA/US, 38 (34%) received tPA/US/MB, and 36 (32%) were treated with tPA alone. Stroke severity, time to treatment, location of MCA occlusion, and presence of carotid artery disease were similar among groups. Two-hour recanalization was seen in 14 (39%), 25 (68%), and 27 patients (71%) in the tPA, tPA/US, and tPA/US/MB groups, respectively (P=0.004). Two-hour complete recanalization rate was significantly (P=0.038) higher in the tPA/US/MB group (54.5%) compared with tPA/US (40.8%) and tPA (23.9%) groups. The time to beginning of recanalization after tPA bolus was 26+/-18 minutes in the tPA/US group and 19+/-12 minutes in the tPA/US/MB group (P=0.12). Four patients (3.6%) experienced symptomatic intracranial hemorrhage: 2 (5.5%), 1 (2.7%), and 1 patient (2.6%) who received tPA only, tPA/US, and tPA/US/MB, respectively, experienced symptomatic intracranial hemorrhage. At 24 hours, 31%, 41%, and 55% of tPA, tPA/US, and tPA/US/MB improved >4 points in the NIHSS score. CONCLUSIONS: Administration of MBs induces further acceleration of US-enhanced thrombolysis in acute stroke, leading to a more complete recanalization and to a trend toward better short- and long-term outcome.

Adult↗
PubMed2006

Intravenous versus combined (intravenous and intra-arterial) thrombolysis in acute ischemic stroke: a transcranial color-coded duplex sonography--guided pilot study.

BACKGROUND AND PURPOSE: Determine feasibility and safety of intravenous (IV) versus combined (IV-IA [intra-arterial]) thrombolysis guided by transcranial color-coded duplex sonography (TCCD). METHODS: Thirty-three patients eligible for IV thrombolysis, within 3 hours of onset of symptoms, with occlusion in middle cerebral artery territory (TCCD monitoring, thrombolysis in brain ischemia [TIBI] flow grade [0-3]), underwent IV thrombolysis (tissue plasminogen activator, 0.9 mg/kg). In case of recanalization (modification of TIBI score > or =1) after 30 minutes IV thrombolysis was continued over 1 hour; otherwise, it was discontinued, with subsequent IA thrombolysis. Recanalization was determined by TIBI (TCCD) and angiographically by thrombolysis in myocardial infarction (TIMI) flow grades. Clinical outcome measures were assessed at baseline, 24 hours (NIHSS) and 3 months (modified Rankin Scale). RESULTS: In the IV group, 10/17 patients (59%) with complete or partial recanalization after 30 minutes had a favorable outcome at 3 months (modified Rankin Scale 0 to 2). TIBI flow grades 3 to 5 after 30 minutes of IV thrombolysis predicted a good prognosis compared with TIBI grades 1 to 2 (P<0.05). In the combined IV/IA therapy group (no recanalization after 30 minutes), 9/16 patients (56%) had a favorable outcome at 3 months. One symptomatic intracerebral hemorrhage occurred in each group. CONCLUSIONS: Combined IV-IA versus IV thrombolysis guided by TCCD was feasible and safe. Recanalization after 30 minutes of IV thrombolysis led to a favorable outcome in 59% of the patients, provided TIBI flow grades were of 3 to 5. In the absence of early recanalization during IV thrombolysis, there was clinical benefit to proceed to IA therapy for a significative proportion of patients (56%).

Acute Disease↗
PubMed1988

Intra-arterial thrombolytic therapy improves outcome in patients with acute vertebrobasilar occlusive disease.

In this retrospective analysis we report our treatment experience in 65 consecutive patients with clinical signs of severe brainstem ischemia with angiographically demonstrated thrombotic vertebrobasilar artery occlusions who received either local intra-arterial thrombolytic therapy (urokinase or streptokinase) (43 patients) or conventional therapy (antiplatelet agents or anticoagulants) (22 patients). We analyzed the data with respect to cerebral artery occlusion patterns, posttreatment arterial recanalization, and the clinical categories of favorable/unfavorable outcome and survival/death. In subgroup analyses, recanalization in patients who received thrombolytic therapy correlated significantly with clinical outcome; in 19 of 43 patients, recanalization was demonstrated angiographically, while in 24 patients the occlusion persisted. All patients without recanalization died, but 14 of the 19 patients displaying recanalization survived (p = 0.000007), 10 with a favorable clinical outcome. Only three of the 22 patients who received conventional therapy survived, all with a moderate clinical deficit. When we compared the treatment groups, highly significant differences in both outcome quality (p = 0.017) and survival (p = 0.0005) were found to depend on establishing recanalization. Our data support the concept that technically successful thrombolysis of vertebrobasilar artery occlusions is associated with beneficial clinical outcome.

Acute Disease↗
PubMed2001

Utility of perfusion-weighted CT imaging in acute middle cerebral artery stroke treated with intra-arterial thrombolysis: prediction of final infarct volume and clinical outcome.

BACKGROUND AND PURPOSE: The goal of this study was to evaluate the utility of perfusion-weighted CT (PWCT) in predicting final infarct volume and clinical outcome in patients with acute middle cerebral artery (MCA) stroke. METHODS: Twenty-two consecutive patients with MCA stem occlusion who underwent intra-arterial thrombolysis within 6 hours of stroke onset had noncontrast CT and CT angiography with whole-brain PWCT imaging before treatment. Infarct volumes were computed from the initial PWCT and follow-up scans; clinical outcome was measured with the modified Rankin scale. RESULTS: Initial PWCT lesion volumes correlated significantly with final infarct volume (P=0.0002) and clinical outcome (P=0.01). For the 10 patients with complete recanalization, the relationship between initial and final lesion volume was especially strong (R(2)=0.94, P<0.0001, slope of regression line=0.92). For those without complete recanalization, there was progression of lesion volume on follow-up imaging (R(2)=0.50, P=0.01, slope of regression line=1.61). All patients with either initial PWCT lesion volumes >100 mL or no recanalization had poor outcomes (Rankin scores, 4 to 6). Mean admission NIH Stroke Scale scores and mean lesion volumes in the poor outcome group were significantly different compared with the good or fair outcome (Rankin scores, 0 to 3) group (21+/-4 versus 17+/-5, P=0.05, and 106+/-79 versus 29+/-37 mL, P=0.01). Patients with initial volumes <100 mL and partial or complete recanalization all had good (Rankin scores, 0 to 2) or fair (Rankin score, 3) outcomes. CONCLUSIONS: Lesion volumes on admission PWCT images approximate final infarct volume for patients with early complete recanalization of MCA stem occlusion. For those without complete recanalization, there is subsequent enlargement of lesion volume on follow-up. Initial PWCT lesion volumes also have predictive value; volumes >100 mL are associated with a poor clinical outcome. In these highly selected patients, initial PWCT lesion volume was a stronger predictor of clinical outcome than was initial NIH Stroke Scale score.

Acute Disease↗
PubMed1998

Percutaneous endoluminal treatment of iliac occlusions: long-term follow-up in 105 patients.

PURPOSE: To evaluate the long-term results of percutaneous recanalization techniques in occluded iliac arteries. METHODS: Percutaneous recanalization was attempted in 105 patients (97 men; mean age 56 years, range 34 to 80) with iliac occlusions using thrombolysis (n = 15), excimer laser (n = 4), mechanical thrombectomy (n = 16), balloon angioplasty alone (n = 23), and angioplasty plus stenting (n = 69). The majority of lesions (n = 72) were in the common iliac artery (CIA); 33 were in the external iliac artery (EIA). RESULTS: The primary recanalization rate was 88% (92/105) independent of location (EIA: 90%, CIA: 86%) and lesion length, but dependent on age of thrombus (< 3 months: 100%, > 3 months: 79%, p < 0.02). Complications included 5 (4.8%) cases of distal embolism treated by thromboaspiration or Fogarty balloon embolectomy. Seven (6.7%) early thromboses were treated surgically. Primary and secondary patency rates were calculated at 6 years for all 105 cases and for the 92 recanalized lesions using life-table analysis. Overall, primary patency was 52% (CIA: 58%, EIA: 34%) and secondary 66% (CIA: 74%, EIA: 40%). Lesions < 6 cm had a primary patency of 70%, while those > 6 cm had a 31% rate (p < 0.01). Secondary patencies were 86% and 42%, respectively (p < 0.01). Among recanalized lesions, the primary patency was 61% (CIA: 69%, EIA: 38%) and secondary 77% (CIA: 88%, EIA: 45%; p < 0.05). Lesions < 6 cm had a primary patency rate of 72%, while longer lesions had a primary rate of 44% (p < 0.04); secondary patencies were 89% and 59%, respectively (NS). Primary patency without stent was 57% and with stent 65% (NS); secondary patency without stent was 71% and with stent 82% (NS). CONCLUSIONS: Percutaneous recanalization of iliac occlusions represents a true alternative to vascular surgery and a first-line treatment option. Stents have a tendency to improve long-term results and are recommended for routine use in chronic iliac occlusions.

Adult↗
PubMed1995

Fibrinolytic therapy for acute embolic stroke: intravenous, intracarotid, and intra-arterial local approaches.

To clarify the efficacy and limitations of the intra-arterial local infusion of a high-dose fibrinolytic agent for acute embolic stroke, we analyzed the results of 44 patients and compared them with those of 51 patients treated with intracarotid (18 patients) or intravenous (33 patients) infusion therapy. Ten megaunits of recombinant tissue plasminogen activator or 24 x 10(4) IU of urokinase were administered through a microcatheter placed into or proximal to an embolus for 20 minutes. When arterial recanalization was not achieved, a second or third infusion was performed. The rates of complete and partial recanalization just after the local infusion were 52 and 32%, respectively. They were high in middle cerebral and basilar artery occlusion and low in internal carotid artery occlusion (69, 78, and 20%, respectively). In our use, there was no difference between tissue plasminogen activator and urokinase in restoring blood flow. The mean time interval from onset to recanalization in patients with middle cerebral artery occlusion showing marked improvement was 4.8 hours, and it was 5.8 hours with basilar artery occlusion. The size of infarction was reduced, and the outcome was good in patients with complete recanalization achieved. The incidence of hemorrhagic infarction within 24 hours was 22%, and only one patient clinically deteriorated. In the intracarotid infusion group (20 x 10(4) IU of urokinase for 30 min), only two patients showed partial recanalization without clinical improvement. The incidence of hemorrhagic infarction was 28%. The outcome in this group and the intravenous infusion group (18 x 10(4) IU of urokinase a day for 1 wk) was poor compared with that in the local infusion group showing complete recanalization. This preliminary study appears to suggest that intra-arterial local fibrinolytic therapy could be a new strategy for acute embolic stroke.

Acute Disease↗
PubMed2006

Durability of aneurysm embolization with matrix detachable coils.

OBJECTIVE: Matrix detachable coils (MDC; Boston Scientific/Target, Fremont, CA) are platinum coils coated with a bioabsorbable polymeric material (polyglycolic-polylactic acid). In animal models, the introduction of polyglycolic-polylactic acid-coated coils into experimental aneurysms resulted in a cellular reaction which promoted stable intra-aneurysmal scar tissue formation. The current study was undertaken to assess the durability of aneurysm occlusion after embolization with MDC. METHODS: All patients undergoing embolization were prospectively enrolled in an endovascular database at our institution. All coils used for embolization were recorded in the operative notes for the procedure. Only aneurysms embolized with 50% or greater length of MDC were included. All patients with Neuroform stents (Boston Scientific/Target, Fremont, CA) were excluded from the study. Patients were followed with conventional angiography and magnetic resonance angiography. RESULTS: During a 20-month period, 131 aneurysms were embolized with MDC. Follow up data (average, 6.9 mo; range, 1.5-22 mo) were available for 82 aneurysms (61 with conventional angiography, 21 with magnetic resonance angiography only). Of the aneurysm patients with follow-up available, 65 had small aneurysms with small necks, three were small aneurysms with wide necks, 12 were large aneurysms, and two were giant aneurysms. Overall, there were 30 (36.6%) recanalizations, 19 (23.1%) of which required retreatment. In two additional patients, retreatment was either recommended (n = 1) or attempted unsuccessfully (n = 1). Fifty-two aneurysms were unchanged or demonstrated progressive thrombosis (63.4%). The recanalization rate for small aneurysms with small necks was 26.1% (17 out of 65) with a 13.8% retreatment rate (9/65). The recanalization rate for large aneurysms was 75% (9 out of 12) with seven requiring retreatment. CONCLUSION: In the absence of Neuroform stent support, aneurysms embolized with the MDC system demonstrated a significant rate of recanalization. Many of the recanalizations were of sufficient size to warrant retreatment. The rates of recanalization observed in the present series were comparable to, or worse than, those reported for bare platinum coils.

Adult↗
PubMed1997

Mitral insufficiency as a complication of acute myocardial infarction and left ventricular remodeling.

The presence of mitral insufficiency after acute myocardial infarction (AMI) often leads to hemodynamic impairment and heart failure. This study was designed to examine the relationship between mitral regurgitation (MR), an indicator of mitral insufficiency, and the course of recovery from AMI. We evaluated the course of MR after AMI in 223 patients by color Doppler echocardiography. MR was detected in 21% (47/223) of patients at the onset of AMI, and developed in 18% (40/223) of patients during follow-up. Patients were grouped according to the course of MR as well as the success of acute recanalization therapy. No correlation was observed between the presence or course of MR and the site of infarction. The incidence of successful recanalization was higher in patients with MR that improved during follow-up than in patients with MR that was unchanged or that worsened during follow-up. Although no significant differences in hemodynamic variables were noted among the groups at admission, the group with unsuccessful recanalization and unimproved MR (BS-) showed a significantly greater left ventricular end-diastolic diameter (LVDd), left ventricular end-systolic diameter, and left ventricular end-diastolic volume (LVEDV) as well as a lower left ventricular ejection fraction than patients with successful recanalization and no MR (CS+) during the convalescent period. The extent of change in LVDd and LVEDV between admission and convalescence was significantly greater in the BS(-) group than in the CS(+) group. The results suggest that successful recanalization after AMI reduces the incidence of MR. Acute recanalization therapy after AMI may prevent left ventricular remodeling, resulting in a secondary improvement of MR.

Aged↗
PubMed1998

Angiographic study of mutant tissue-type plasminogen activator versus urokinase for acute myocardial infarction.

The effects and problems of intravenous thrombolytic therapy with a bolus injection of mutant tissue plasminogen activator (t-PA) were investigated in 34 patients with first acute myocardial infarction (AMI). In contrast, 114 patients were selected from 1,003 patients with AMI for treatment using intravenous infusion urokinase (UK). Angiography of these 148 patients revealed a complete occlusion of infarct-related artery with no clear contraindications to the study treatment. With the exception of thrombolysis in myocardial infarction (TIMI-3) recanalization 60 min after a bolus injection of mutant t-PA, the patients were given intracoronary UK in addition to mutant t-PA. The study comparisons were assessed using the following criteria: (1) 60-min assessment of recanalization rates, mutant t-PA vs UK; (2) time interval from initiation of thrombolysis to recanalization, mutant t-PA vs UK; (3) angiographic reocclusion rates within 1 month, mutant t-PA alone vs UK vs mutant t-PA plus UK; and (4) intracerebral hemorrhage rates, mutant t-PA alone vs UK vs mutant t-PA plus UK. There were no significant differences in the recanalization rates between mutant t-PA and UK, but there was a significant reduction in the time to recanalization with mutant t-PA (31.8 +/- 12.7 min) compared with UK (56.5 +/- 6.3 min). There was a significant difference in the reocclusion rates among the 3 treatment groups (20% mutant t-PA alone vs 4% UK vs 0% mutant t-PA plus UK). On the other hand, no significant differences in intracerebral hemorrhage rates among the 3 treatments were observed. In conclusion, thrombolytic therapy with a bolus injection of mutant t-PA achieved more rapid recanalization, but treatment with mutant t-PA led to a high rate of reocclusion.

Acute Disease↗
PubMed1994

Pattern of failure and survival in endobronchial laser resection. A matched pair study.

To evaluate the influence of endobronchial laser resection on survival and the pattern of failure in patients with bronchial malignancies, we investigated 75 patients prospectively. These patients had radiation therapy (mean external dose, 53.1 Gy) and endobronchial laser resection to treat an inoperable or recurrent bronchial carcinoma occluding a major airway. Complete recanalization was achieved in 36 percent, partial recanalization was achieved in 51 percent, and no recanalization was achieved in 13 percent. These 75 patients were matched retrospectively with a group of 75 patients who received external radiation therapy because of the same indications, but because of endobronchial compression of a major airway by the tumor, received no laser resection. The patients were matched for age, sex, TNM-status, histologic features, external radiation dose and fractionation, lung resection, cytotoxic therapy, and brachytherapy; they were treated in the same period. The incidence of terminal hemorrhage was four times higher in patients who received endobronchial laser resection (34.5 percent) compared with those who did not (7.7 percent). Successful laser reopening of a major airway influenced the pattern of failure: with full recanalization the cause of death in 23.3 percent of cases was respiratory failure and in 26.7 percent, terminal hemorrhage; whereas with no recanalization these figures were 56.3 percent and 18.8 percent, respectively. Laser resection did not influence overall survival, but in patients with full reopening of a bronchus, the time interval from treatment to death was prolonged by more than 4 months compared with those patients in whom recanalization failed. Comparing our observations on the immediate cause of death with reports in the literature, we conclude that the higher percentage of terminal hemorrhage in patients receiving endobronchial laser resection is not directly related to the treatment, but reflects different patterns of tumor growth with respect to mucosal destruction not covered by the TNM system.

Bronchial Neoplasms↗
PubMed1994

Intra-carotid thrombolytic therapy in acute ischemic stroke of carotid arterial territory.

Intra-carotid urokinase (UK) infusion in 20 patients with acute internal carotid artery (ICA) territorial ischemic stroke achieved immediate recanalization in 45% and the clinical outcome in patients with recanalization was superior to that of patients without recanalization. The procedure was most effective in patients with smaller arterial occlusions: 7 of 10 patients with MCA branch occlusions (M2 to M4) achieved recanalization compared to only 2 of 10 with distal ICA or M1 occlusions, which should be an important issue for the critical evaluation of the efficacy of thrombolytic therapy (TT). Hemorrhagic transformation was observed in 9 patients on CT scan; petechial hemorrhage in 5 and intraparenchymal hematoma formation in 4. Among 4 patients with hematoma formation, clinical deterioration was seen in 3 cases and the angiography at the immediate end of the UK infusion showed recanalization in only one patient. The average dose of UK in patients with parenchymal hematoma formation was higher than that of patients without hemorrhagic transformation (123.3 x 10(4) units vs 101 x 10(4) units). The administration of a large dose of UK, probably more than 100 x 10(4) units, and the absence of immediate recanalization seemed to increase the risk of parenchymal hematoma formation. Despite the effort of investigators, the in-hospital time delay for the TT was significant which was mainly related to the time consuming preparation for angiography especially during night. A more effective system for the earlier intervention of acute ischemic stroke needs to be developed.

Adult↗
PubMed2001

Stroke magnetic resonance imaging within 6 hours after onset of hyperacute cerebral ischemia.

We studied the diagnostic and prognostic value of diffusion- and perfusion-weighted magnetic resonancce imaging (DWI and PWI) for the initial evaluation and follow-up monitoring of patients with stroke that had ensued less than 6 hours previously. Further, we examined the role of vessel patency or occlusion and subsequent recanalization or persistent occlusion for further clinical and morphological stroke progression so as to define categories of patients and facilitate treatment decisions. Fifty-one patients underwent stroke magnetic resonance imaging (DWI, PWI, magnetic resonance angiography, and T2-weighted imaging) within 3.3 +/- 1.29 hours, and, of those, 41 underwent follow-up magnetic resonance imaging on day 2 and 28 on day 5. In addition, we assessed clinical scores (on the National Institutes of Health Stroke Scale, Scandinavian Stroke Scale, Barthel Index, and Modified Rankin Scale) on days 1, 2, 5, 30, and 90 and performed volumetric analysis of lesion volumes. In all, 25 patients had a proximal, 18 a distal, and 8 no vessel occlusion. Furthermore, 15 of 43 patients exhibited recanalization on day 2. Vessel occlusion was associated with a PWI-DWI mismatch on the initial magnetic resonance imaging, vessel patency with a PWI-DWI match (p < 0.0001). Outcome scores and lesion volumes differed significantly between patients experiencing recanalization and those who did not (all p < 0.0001). Acute DWI and PWI lesion volumes correlated poorly with acute clinical scores and only modestly with outcome scores. We have concluded on the basis of this study that early recanalization saves tissue at risk of ischemic infarction and results in significantly smaller infarcts and a significantly better clinical outcome. Patients with proximal vessel occlusions have a larger amount of tissue at risk, a lower recanalization rate, and a worse outcome. Urgent recanalization seems to be of utmost importance for these patients.

Aged↗
PubMed2003

Clinical application of interventional techniques in the treatment of Budd-Chiari syndrome.

OBJECTIVE: To evaluate the clinical value of various kinds of interventional techniques in the treatment of Budd-Chiari syndrome (BCS). METHODS: Multiple techniques such as recanalization of the inferior vena cava (IVC) under the guidance of marker and multi-angled fluoroscopy, recanalization of the hepatic vein with a transjugular approach, PTA, Z-expandable metallic stent (Z-EMS) implantation and modified TIPSS were used to treat 103 patients with BCS. RESULTS: Of 103 patients with BCS, 59 patients with obstruction of IVC were treated using recanalization of IVC. Seventeen patients with hepatic vein obstruction had their hepatic veins recanalized. The rest of the patients were given other methods of interventional treatment. Of all the subjects, 101 successfully underwent their procedures, with a success rate of 98.06%; and only 2 failed to recanalization of the IVC. Fifty-three patients were treated using PTA for the first time, with a success rate of 100%. In the 48 patients undergoing Z-EMS implantation for the first time, the success rate was 95.8%. Five patients were treated with modified TIPSS. After these interventional treatments, the success rate was 100%. Two patients died 16 h and 72 h respectively after operation because of DIC and severe hemoptysis. Seventy-two patients were followed up for 1 - 94 months (with a mean of 42.3 months). The mean follow-up of a BCS patient treated with PTA was 52.1 months, resulting in a primary patent rate of 59.4% and a restenosis rate of 40.6%. The mean follow-up of BCS treated with stenting was 33.5 months, with a primary patent rate of 87.5% and a restenosis rate of 12.5%. Eight patients died 7 - 64 months after the interventional procedure. CONCLUSION: Recanalization of IVC or the hepatic vein transjugularly, PTA, Z-EMS implantation and modified TIPSS can be regarded as safe and effective micro-invasive methods in the treatment of BCS.

Adolescent↗