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 1,459 records · Page 81Linked to original sources
PubMed2005

Long-term treatment of deep venous thrombosis with a low molecular weight heparin (tinzaparin): a prospective randomized trial.

OBJECTIVES: Evaluation of the effectiveness and safety of the low molecular weight heparin (LMWH) tinzaparin versus unfractionated heparin (UFH) followed by acenocoumarol in proximal deep venous thrombosis (DVT). DESIGN: Prospective, randomized clinical trial. MATERIAL AND METHODS: Consecutive patients (n=108) with acute leg DVT, confirmed by duplex, were randomized to either tinzaparin alone or UFH and acenocoumarol for 6 months. Patients were evaluated ultrasonographically at entry, 1, 3, 6 and 12 months. Thrombus regression, reflux distribution and the incidence of complications were studied. A cost-analysis, comparing the two treatments, was performed. RESULTS: The overall incidence of major events (mortality, DVT recurrence, pulmonary embolism, major bleeding, heparin-induced thrombocytopenia) was significantly different (p=0.035) in favor of tinzaparin (7 versus 17 events). The ultrasonographic clot volume score (an index of recanalization) decreased significantly in both treatment groups. However, tinzaparin produced significantly more extended overall recanalization from 3 months onwards (p<0.02). Thrombus regression was equivalent or in favor of tinzaparin in the different DVT subgroups and venous segments, but the statistical significance varied. Reflux showed non-significant differences overall or in subgroups. A cost-analysis resulted in favor of LMWH. CONCLUSIONS: A fixed daily dose of tinzaparin for 6 months was at least as effective and safe as UFH and acenocoumarol. Regarding major events and recanalization, there was a significant benefit in favor of tinzaparin. Long-term DVT treatment with tinzaparin could represent an alternative to conventional treatment.

Acenocoumarol↗
PubMed2005

Prediction of decrease in myocardial perfusion defect size and severity during a 3-month follow-up by the degree of acute resolution of electrocardiographic changes.

Myocardial perfusion in infarct-related artery (IRA) distribution improves progressively until a few months after successful reperfusion therapy. We assessed the rate of electrocardiographic (ECG) stage dynamics to predict perfusion improvement after mechanical, thrombolytic, or spontaneous recanalization of IRA. Thirteen patients were divided into group A (n = 8, with > or = 2 ECG stages per 2-day change rate) and group B (n = 5, no rapid change of ECG stages). There were no significant technetium Tc 99m sestamibi scintigraphic differences between the groups 3 days after recanalization; however, after 3 months, perfusion deficit size (2.8 +/- 1.8 vs 4.8 +/- 1.2, P < or = .03) and severity (1.8 +/- 0.9 vs 3.0 +/- 0, P < or = .03) were smaller in group A vs group B. The prediction sensitivity of the method was 87.5% for decrease in size and 100% for decrease in severity of perfusion defect; the specificity was 80% and 100%, respectively. A change rate of 2 or more ECG stages per 2 days predicts follow-up improvement of myocardial perfusion after IRA recanalization.

Coronary Circulation↗
PubMed2004

Cryorecanalization: a new approach for the immediate management of acute airway obstruction.

OBJECTIVES: Endobronchial cryotherapy is an established recanalization method for stenoses of the respiratory tract. However, previous applications of cryotherapy have not been immediately effective, requiring a second clean-up procedure several days later to finally obtain sufficient recanalization. In this study we demonstrate a newly developed cryoprobe allowing recanalization of tumor stenoses during a single intervention. METHODS: In this prospective study flexible bronchoscopy was used for cryorecanalization of 60 patients with high-grade stenoses of the respiratory tract from exophytic tumors. Tumor tissue was frozen on the tip of the probe and subsequently removed from the surrounding respiratory tract tissue through retraction of the probe. Procedures were carried out on sedated, spontaneously breathing, intubated patients. RESULTS: Fifty (83%) of 60 patients were successfully or partially successfully treated. Tumor bleeding occurred in 6 patients but was stopped with argon plasma coagulator treatment in all patients not requiring rigid bronchoscopy. CONCLUSION: Cryorecanalization with the newly developed cryoprobe permits effective, safe, and inexpensive therapy of endobronchial stenoses of the respiratory tract.

Acute Disease↗
PubMed2004

Ultrasound findings after radiofrequency ablation of the great saphenous vein: descriptive analysis.

OBJECTIVE: As an emerging endovascular alternative to ligation and stripping of the incompetent greater saphenous vein (GSV), radiofrequency ablation was monitored with ultrasound scanning to evaluate anatomic results. Neovascularization and inflammation are potential consequences that lead to the appearance of small vessels. The natural history of the below-knee untreated GSV segment may be important in our understanding of ongoing chronic venous disease. An ultrasound follow-up study was conducted to determine the prevalence of small vessel networks, defined as veins and arteries less than 2 mm in diameter, adjacent to the saphenofemoral junction (SFJ); prevalence of small vessel networks adjacent to the treated GSV in the thigh; and fate of the below-knee untreated GSV distal to the ablated segment. METHODS: One hundred six extremities with radiofrequency ablation of the GSV for treatment of superficial venous insufficiency were followed up with high-resolution ultrasound imaging 4 to 25 months (median, 9 months) after the procedure. Ninety-three limbs had concomitant ligation and division of the SFJ and its tributaries, and 13 limbs underwent radiofrequency ablation without SFJ ligation. Ultrasound was used to evaluate patients for small vessel networks, and concomitant findings of small vessel networks and recanalization at the SFJ and adjacent to the treated GSV. The status of the below-knee segment of untreated GSV was evaluated for patency and reflux. Data analysis compared the findings in the ligation group with those in the no-ligation group, with the chi 2 test and Fisher exact test. RESULTS: We found small vessel networks in 65% (n = 69) of extremities: 15% (n = 16) at the SFJ only, 26% (n = 28) in the thigh only, and 24% (n = 25) at both the SFJ and thigh, resulting in a small vessel network prevalence of 39% (n = 41) at the SJF and 50% (n = 53) in the thigh. The prevalence of small vessel networks at the SFJ was significantly less after radiofrequency ablation with SFJ ligation (34%, 32 of 93) than after radiofrequency ablation without ligation (69%, 9 of 13; P = .035). Small vessel networks and GSV recanalization at the SFJ was more common in patients undergoing radiofrequency ablation without ligation (46%, 6 of 13) than after radiofrequency ablation with ligation (14%, 13 of 93; P = .014). The prevalence of small vessel networks in the thigh was not affected by SFJ ligation. The below-knee GSV was patent in 79% (84 of 106), and 58% (61 of 106) demonstrated reflux, a decrease from the pre-radiofrequency ablation rate of 71% (75 of 106), possibly because thrombosis extended distally beyond the ablated segment in 16% (17 of 106) of the legs. CONCLUSIONS: Small vessel networks were detected adjacent to or in connection with most of the radiofrequency ablation-treated GSVs. SFJ ligation was associated with fewer small vessel networks and proximal GSV recanalization. Most below-knee untreated GSV segments remained patent, and most exhibited reflux.

Adult↗
PubMed2006

Monocyte recruitment in venous thrombus resolution.

OBJECTIVE: To investigate the importance of monocyte recruitment in thrombus resolution and the role of cysteine-cysteine (CC) chemokines and the CC chemokine receptor, CCR2, in this process. METHODS: Peritoneal macrophages, monocyte chemotactic protein 1 (MCP1), or carrier solutions were injected into thrombi induced in the vena cava of rats. Caval thrombi were also formed in CCR2-/- and MCP1-/- mice and in wild-type mice transfected with an adenoviral construct expressing a broad-spectrum CC receptor antagonist. RESULTS: Direct administration of peritoneal macrophages decreased thrombus size by more than fivefold and increased recanalization by more than fourfold compared with controls (P < .001). A 100-ng MCP1dose reduced thrombus size by more than sixfold (P < .01) and increased recanalization by more than sevenfold (P < .01), without affecting macrophage recruitment. Deletion of CCR2 or blockade of all CC chemokines inhibited both monocyte recruitment (P < .05) and thrombus resolution (P < .01), but knocking out MCP-1 had no effect. CONCLUSION: Increasing macrophage numbers in the thrombus enhances its resolution. MCP1 treatment enhances resolution by stimulating recanalization, independent of an effect on monocyte recruitment. CCR2 deficiency has the same effect as blockade of all CC chemokines. CCR2 receptor activation may therefore be an important mechanism in monocyte recruitment into venous thrombi and could be targeted to promote their resolution.

Animals↗
PubMed1984

Thrombolytic therapy in acute myocardial infarction: review of clinical trials.

Intracoronary infusion of streptokinase is associated with recanalization rates of 60 to 90% immediately after the procedure. Mortality data in published trials are conflicting. In 125 registry patients who had paired contrast ventriculograms before streptokinase infusion and hospital discharge, improvement in ejection fraction correlated with incomplete coronary obstruction before angiography, the presence of collateral vessels to the infarct area and recanalization of complete obstruction. In assessing the risk/benefit ratio of intracoronary streptokinase infusion, the risks of angiography in the setting of acute myocardial infarction, reocclusion, bleeding and such secondary interventions as angioplasty or bypass surgery must be considered. Intravenous infusion of conventional doses of streptokinase was associated with improved survival in some trials in which therapy began within 12 hours after the onset of infarction. Immediate recanalization rates in patients who received large doses of intravenous streptokinase were lower than those associated with intracoronary streptokinase infusion. The risks and benefits of high-dose intravenous streptokinase administration must still be assessed.

Clinical Trials as Topic↗
PubMed1988

Advances in balloon technology and reperfusion devices for peripheral circulation.

Major improvements in balloon and wire technology have been occurring for several years and, consequently, the approach to conventional angioplasty has been simplified. Results in isolated stenotic segments in renal circulation and within the iliac and superficial femoral vessels have generally been 95% technically successful, with 1-year patency rates of 80% in the superficial and renal sites and 90% in the iliac vessels. The procedure has been extended to include more distal vessels including the popliteal and tibial circulation as well as more complex lesions involving the mesenteric circulation and pre-Leriche syndromes with stenotic disease involving the infrarenal segment of the abdominal aorta. Successful results have also been achieved in stenotic atherosclerotic disease involving the subclavian artery and the associated subclavian steal syndromes. Preliminary results are also being reported in a few selected series of vertebral and carotid artery angioplasty. Totally occluded segments in the iliac and peripheral circulation had previously been ammenable only to surgical bypass procedures. A series of new recanalization devices are under investigational evaluation for reperfusing these totally obstructed segments. Although technical recanalization in segments as long as 20 cm can be accomplished in approximately 75% of these patients, long-term patency is totally dependent on popliteal-tibial outflow. For these reasons, diffuse disease and totally obstructive disease in the superficial femoral vessels can have recurrence rates as high as 45%, and reestablishing tibial outflow is equally as important as successfully recanalizing the totally obstructed superficial femoral vessels.

Angioplasty, Balloon↗
PubMed1985

Thrombolytic therapy followed by first rib resection for spontaneous ("effort") subclavian vein thrombosis.

Spontaneous (effort) subclavian vein thrombosis in young persons has historically produced long-term disability from arm swelling and exercise limitation because of failure of the occluded vein to recanalize. Several investigators have speculated that the use of thrombolytic therapy to produce clot dissolution followed by resection of the first rib to prevent recurrence might be ideal management of this condition. Our recent experience with treatment of two such patients formed the basis for this report. Two young men were seen within 24 hours of onset of acute arm swelling, found by venography to be caused by acute thrombosis of the subclavian vein at the level of the first rib. They were treated with systemic thrombolytic therapy with intravenous streptokinase. Both had prompt resolution of all signs and symptoms, confirmed by repeat venography to be accompanied by recanalization of the occluded veins. Both were then anticoagulated with heparin followed by warfarin and underwent elective first rib resection, after which anticoagulation was discontinued. Both patients have remained asymptomatic. Persistent venous patency has been confirmed by repeat venography. Thrombolytic therapy to recanalized spontaneous (effort) subclavian vein thrombosis followed by first rib resection appears to be an advance in the treatment of this condition and may avoid the long-term disability with which it has historically been associated.

Adolescent↗
PubMed2000

Revascularization of canine cryopreserved tracheal allografts.

BACKGROUND: We examined the blood supply of a cryopreserved tracheal allograft and its morphohistologic changes after transplantation. METHODS: In each of 22 dogs, a five-ring tracheal segment was replaced by one of the following tracheal grafts: fresh autografts (n = 8), cryopreserved tracheal allografts (n = 8), or fresh allografts (n = 6). The cryopreserved tracheal allografts were preserved at -196 degrees C for 60 days. No immunosuppressant was given to any of the animals. All grafts were retrieved at 1 and 12 weeks and assessed by microangiography and histology. RESULTS: The epithelial denudation and the revascularization of the transverse intercartilaginous arteries were recognized within 7 days as common to each of the three types of grafts. In the cryopreserved tracheal allografts, neither cartilage degradation nor graft shrinkage occurred at 7 days. However, the recanalized transverse intercartilaginous arteries completely disappeared at 12 weeks, and marked shrinkage occurred; the cartilage cells were accompanied by karyolysis and were significantly decreased in number (p < 0.05). Recanalization of the transverse intercartilaginous arteries was also demonstrated in the fresh allografts; however, necrosis abruptly occurred as a result of acute rejection responses. CONCLUSIONS: Cryopreservation of a tracheal allograft provided sufficient reduction of the acute rejection responses, and blood supply to the cryopreserved tracheal allograft was established through the recanalized transverse intercartilaginous arteries within 7 days; however, subsequent chronic rejection responses resulted in occlusion of the transverse intercartilaginous arteries and atrophy.

Animals↗
PubMed2002

Combined X-ray angiography and diffusion-perfusion MRI for studying stroke evolution after rt-PA treatment in rats.

Clinical studies on rt-PA (recombinant tissue-type plasminogen activator) treatment of stroke showed a favorable outcome. However, there are reports of harmful effects of t-PA via the potentiation of excitotoxic injury. We used combined X-ray angiography and MRI imaging to study the balance between the beneficial effect of reperfusion and secondary detrimental effects of rt-PA. Therefore, rats (n=15) were assigned to three groups according to recanalization or lack thereof of the middle cerebral artery (MCA) and rt-PA or saline treatment in an embolic stroke model. Diffusion and perfusion MRI showed that animals had significantly improved perfusion values and final infarct size when recanalization was successful. However, final infarct volumes at 6 h post stroke onset were greater in the rt-PA group compared to controls at comparable perfusion values when the MCA did not recanalize after treatment (67.4+/-5.4 versus 47.7+/-17.9% of ipsilateral hemisphere, P=0.042). Our results demonstrate that the combination of angiography and MR-imaging is useful to further evaluate rt-PA treatment of thromboembolic stroke.

Animals↗
PubMed1995

Percutaneous transluminal angioplasty in femoral artery occlusions: primary and long-term results in 107 claudicant patients using femoral and popliteal catheterization techniques.

To assess the impact of percutaneous transluminal angioplasty (PTA) of occluded femoral arteries, a prospective study of 107 claudicant patients was performed. A total of 117 limbs were treated and were followed for 1-36 months; the mean length of treated occlusions was 7.4 cm (range 2-25 cm). Eighty-nine recanalizations were performed using antegrade femoral and 28 using the retrograde popliteal catheterization technique. With logistic regression a short length of occlusion correlated favourably with early success. Including rePTAs and applying standardized criteria, survival analysis with the Kaplan-Meier method revealed a 3-year secondary patency rate of 55% for all the treated limbs. The following factors had negative influence on primary patency after successful recanalization; presence of soft thrombotic material in the recanalized artery segment and the presence of focal dissections after PTA. In univariate and multiple logistic regression analysis, male gender and a lesser extent of the atherosclerotic disease (assessed by the number of diseased vessels in the treated limb) correlated with a lower frequency of PTA procedure complications. There was no statistically significant difference in the complications, in the primary success or in the long-term results using either the femoral or popliteal route. However, the popliteal approach improved the early success of the originally antegrade access group by 6% and increased by about one-fifth the number of patients considered technically feasible for PTA in femoral artery occlusions. PTA can be used in femoral artery occlusions up to 10 cm long and it is especially suitable in femoral artery occlusions not exceeding 5 cm in length. PTA can be tried in femoral artery occlusions exceeding a length of 10 cm if operative treatment is not suitable.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Laser versus laser plus afterloading with iridium-192 in the palliative treatment of malignant stenosis of the esophagus: a prospective, randomized, and controlled study.

Thirty-nine patients with malignant stenoses of the esophagus (22 adenocarcinomas, 17 squamous cell carcinomas) were treated either with Nd:YAG laser recanalization alone (N = 20) or with laser recanalization and subsequent endoluminal afterloading irradiation with iridium-192 at a dose of 3 x 7 Gy (6 x 7 Gy). Squamous cell carcinoma patients in the afterloading group showed a prolonged dysphagia-free first interval (65 vs. 30 days, p less than 0.03), while patients with an adenocarcinoma did not share this benefit, and had a need for more frequent endoscopic procedures (p less than 0.05). The complication of esophagitis was only seen following afterloading treatment (21%, N = 4). Re-stenosis occurred in all patients. Neither the duration of relative dysphagia nor survival time was prolonged after endoluminal irradiation in adenocarcinoma or squamous cell carcinoma patients. After prior laser recanalization, palliative afterloading treatment with iridium-192 would seem helpful only in cases of squamous cell carcinoma with a high performance status with the aim of prolonging the first dysphagia-free interval.

Adenocarcinoma↗
PubMed2001

Clinical experiences with low-molecular weight heparins in pediatric patients.

The courses of 79 children (2 weeks to 19 years old) treated with two different low-molecular weight heparins (LMWHs)--nadroparin (n=66) and enoxaparin (n=13)--were retrospectively analysed. In 62 patients, LMWHs were given for short-term prophylaxis (1-2 weeks) during immobilization after surgery or trauma. Thirteen children with thromboembolic events received long-term prophylaxis with LMWHs for 2-18 months--six after thrombolytic therapy and seven after therapy with unfractionated heparin (UFH). Because of thromboembolic events, four patients were initially treated with LMWHs. In all patients with short-term prophylaxis, no thrombosis occurred. After thrombolytic therapy, three children had no reocclusion, two had no thrombus apposition and one had complete recanalization. In the seven patients treated with LMWHs after UFH, four had no reocclusion, two had recanalization and one had reocclusion. In all patients receiving LMWHs for initial treatment of thrombosis, no thrombus apposition, but also no recanalization, occurred. For short-term prophylaxis, nadroparin was used independent of the body weight and without determination of anti-factor Xa (anti-FXa) activity. Long-term prophylaxis was given mainly as doses of 45-100 anti-FXa U/kg resulting in anti-FXa activities between 0.2 and 0.4 U/ml. For treatment of thrombosis, doses of 200-300 anti-FXa U/kg corresponded to 0.5-1.0 anti-FXa U/ml. Side effects--slight gastrointestinal bleeding and temporary reversible hair loss--were seen in two patients. In conclusion, LMWHs proved to be efficacious and safe especially in prophylaxis of thromboembolic events in children.

Adolescent↗
PubMed1999

Embolectomy for acute embolic occlusion of the internal carotid artery bifurcation.

BACKGROUND: Acute occlusion of the distal intracranial segment of the internal carotid artery (ICA) causes sudden severe hemispheric ischemia. A low rate of recanalization and a high mortality rate for this condition have been noted, even with endovascular treatment. METHODS: We report the results of emergency embolectomy in six patients with acute embolic occlusion of the internal carotid artery (ICA) bifurcation. All six patients were admitted to our institute within 2 h of the onset of symptoms. Computed tomography (CT) scans on admission revealed no low-density or high-density regions in any patients. The time between onset of symptoms and completion of angiography ranged from 2 to 4 h (2.8 +/- 0.7 h). RESULTS: Emergency embolectomy was performed for each patient. Recanalization was confirmed angiographically in four of the patients. In the remaining two patients, massive infarction in the territory of the ICA was detected on the CT scans obtained the day of the operation, and postoperative angiography was not performed in these two cases. These two patients died of uncal herniation 6 days after onset. Two of the six patients were able to walk with a cane 2 months after surgery. The remaining two patients were unable to walk or attend to their own bodily needs without assistance. The time elapsed between onset of symptoms to reopening of the occluded vessel was within 6 h in the four surviving patients. The recanalization rate was 66.7% (4/6) for the embolectomy procedure, significantly higher than that (12.5%) of the thrombolytic therapy reported in a previous study. CONCLUSIONS: In summary, open embolectomy can be performed when the time after onset of symptoms is less than 6 h.

Acute Disease↗
PubMed2001

A randomized double-blind trial of intravenous trimetazidine as adjunctive therapy to primary angioplasty for acute myocardial infarction.

BACKGROUND: Despite high patency rates, primary angioplasty for myocardial infarction does not necessarily result in optimal myocardial reperfusion and limitation of infarct size. Experimentally, trimetazidine limits infarct size, decreases platelet aggregation, and reduces leukocyte influx into the infarct zone. To assess trimetazidine as adjunctive therapy to primary angioplasty for acute myocardial infarction a prospective, double-blind, placebo-controlled pilot trial was performed. METHODS: 94 patients with acute myocardial infarction were randomized to receive trimetazidine (40 mg bolus followed by 60 mg/day intravenously for 48 h) (n=44) or placebo (n=50), starting before recanalization of the infarct vessel by primary angioplasty. Patients underwent continuous ST-segment monitoring to assess return of ST-segment deviation to baseline and presence of ST-segment exacerbation at the time of vessel recanalization. Infarct size was measured enzymatically from serial myoglobin measurements. Left ventricular angiography was performed before treatment and repeated at day 14. RESULTS: Blinded ST segment analysis showed that despite higher initial ST deviation from baseline in the trimetazidine group (355 (32) vs. 278 (29) microV, P=0.07), there was an earlier and more marked return towards baseline within the first 6 h than in the placebo group (P=0.014) (change: 245 (30) vs. 156 (31) microV respectively, P=0.044). There was a trend towards less frequent exacerbation of ST deviation at the time of recanalization in the trimetazidine group (23.3 vs. 42.2%, P=0.11). There was no difference in left ventricular wall motion at day 14, or in enzymatic infarct size. There was no side effect from treatment. Clinical outcomes were similar between groups. CONCLUSION: Trimetazidine was safe and led to earlier resolution of ST-segment elevation in patients treated by primary angioplasty for acute myocardial infarction.

Adolescent↗
PubMed2003

Determinants of target vessel failure in chronic total coronary occlusions after stent implantation. The influence of collateral function and coronary hemodynamics.

OBJECTIVES: The goal of this study was to assess the influence of collateral function, coronary hemodynamics, and the angiographic result on the risk of target vessel failure (TVF) after recanalization of a chronic total coronary occlusion (CTO). BACKGROUND: Collaterals may have an adverse effect on TVF. METHODS: In 111 consecutive patients, a CTO (duration >2 weeks) was successfully recanalized with stent implantation. Collateral function was assessed by intracoronary Doppler flow velocity and pressure recordings distal to the occlusion. Baseline collateral function was determined before the first balloon inflation, and recruitable collateral function after stenting during a balloon reocclusion. Finally, the coronary flow velocity reserve (CFVR) and the fractional flow reserve (FFR) were measured. RESULTS: Angiographic follow-up after 5 +/- 4 months in 106 patients showed a reocclusion in 17% and a restenosis in 36%. The major determinants of TVF were the stent length (p < 0.01) and number of implanted stents (p < 0.01). No difference was observed in baseline or recruitable collateral function between patients with and without TVF; 52% of patients had a CFVR >or= 2.0, and only 18% a CFVR >or=2.5 after percutaneous transluminal coronary angioplasty, but neither cutoff-value predicted TVF. A low FFR discriminated patients with reocclusion (0.81 +/- 07 vs. 0.86 +/- 08, p < 0.05) but not with restenosis (0.87 +/- 0.06). CONCLUSIONS: This study showed that there is no relation between a well-developed collateral supply and the risk of TVF in recanalized CTOs. This was rather determined by the stented segment length. There was also no adverse effect of the frequently observed impaired CFVR on TVF, whereas a low FFR was associated with a higher risk of reocclusion.

Aged↗
PubMed1986

Percutaneous transluminal coronary angioplasty after thrombolytic therapy: a prospective controlled randomized trial.

In 162 patients with acute transmural myocardial infarction, combined intravenous and intracoronary thrombolytic therapy with streptokinase was initiated. In vessels that remained occluded, mechanical recanalization was performed with a 3F recanalization catheter (group I, n = 79) or a 4F Grüntzig balloon catheter (group II, n = 83). After reperfusion, intracoronary streptokinase was administered superselectively. After termination of streptokinase infusion, angioplasty was performed only in patients in group II. There was no difference between the groups in relation to sex, age, infarct location, creatine kinase levels and time between onset of symptoms and start of treatment. Initial coronary angiography showed an open vessel in 27 (34%) of 79 patients in group I and 21 (25%) of 83 patients in group II. The final reperfusion rate was 90% (71 of 79) in group I and 86% (71 of 83) in group II. Angioplasty was attempted in 69 of the 71 patients in group II with a success rate of 65% and an occlusion rate of 3%. During the hospital stay, reocclusion occurred in 14 (20%) of 71 patients in group I. After thrombolytic therapy, coronary luminal narrowing in group I was 75 +/- 17% in patients without and 87 +/- 6% in patients with reocclusion (p less than 0.05). In group II, reocclusion was found in 10 (14%) of 71 patients. After angioplasty, the degree of coronary stenosis in group II was reduced from 82 +/- 12 to 51 +/- 30% (p less than 0.001). Reocclusion was found in 3 (7%) of the 45 patients with successful angioplasty and in 7 (32%) of the 22 patients with unsuccessful angioplasty (p less than 0.01). Improvement in regional left ventricular function was observed only in patients from group II with anterior myocardial infarction. In conclusion, by combined medical and mechanical recanalization, the rate of coronary reperfusion can be increased and infarct time shortened, providing the possibility of full revascularization by angioplasty, with improvement of regional wall motion and reduction of the rate of reocclusion.

Adult↗
PubMed1997

Dissolution of thrombotic arterial occlusion by high intensity, low frequency ultrasound and dodecafluoropentane emulsion: an in vitro and in vivo study.

OBJECTIVES: We examined the effectiveness of the microbubbles of an echo contrast agent, dodecafluoropentane (DDFP) emulsion, to enhance low frequency ultrasound clot disruption in vitro and in vivo. BACKGROUND: Ultrasound is reported to facilitate clot dissolution, and microbubbles could theoretically enhance ultrasound clot dissolution by augmenting cavitational effects. METHODS IN VITRO STUDIES: The disruption rate of fresh human clots by ultrasound (24 kHz, 2.9 W/cm2) was examined in saline and DDFP emulsion. In vivo studies: Using a rabbit iliofemoral thrombotic occlusion model, recanalization rate and histopathologic findings were compared among groups treated with DDFP emulsion alone, transcutaneous ultrasound (20 kHz, 1.5 W/cm2) alone and with DDFP emulsion and ultrasound combined. RESULTS: The ultrasound clot disruption rate was significantly (p < 0.01) increased, from 72 +/- 18% (mean +/- SD) in saline to 98 +/- 4% in DDFP emulsion in 3 min in vitro. No vessel was recanalized by DDFP emulsion alone (0%), and only a single artery was patent after ultrasound treatment alone (9%). In contrast, 82% of iliofemoral arteries were angiographically recanalized after ultrasound treatment with DDFP emulsion. Histologically, the patent arteries had only minimal focal mural thrombus, with no evidence of vessel wall damage. However, substantial damage was observed in rabbit dermis and subcutaneous tissue. CONCLUSIONS: 1) DDFP emulsion, an echo contrast agent, significantly enhances the clot-disrupting effect of low frequency ultrasound in vitro and in an in vivo rabbit iliofemoral occlusion model. 2) This simple combination therapy has potential for clinical application in patients with thrombotic arterial occlusions.

Animals↗