PubMed HealthSearch

SEARCH · PubMed Health

Results for “Recanalization”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources

[Recanalization by catheter of the occluded artery after acute myocardial infarction (transluminal recanalization (author's transl)].

Using guide-wires and special catheters the occluded infarct-related coronary artery was recanalized in 10 patients with acute myocardial infarction 6.6 +/- 7.1 hours after the onset of symptoms. There were no complications. Immediately after recanalization there were 80-95% lesions at the site of the previous occlusion. Angiography, performed in 9 patients in the chronic stage of myocardial infarction, revealed patency of the recanalized vessel in all instances. There was a marked decrease in the narrowing at the time of the second angiogram in 6 patients. Changes in left ventricular function from the acute to the chronic stage were assessed in 8 patients: the ejection fraction increased in 6. The results of this pilot study indicate that transluminal recanalization of acutely occluded coronary arteries is possible without harmful side-effects. Early restoration of flow may salvage the jeopardized myocardium. Further application of this method of treatment in selected patients and efforts to improve the technique seem to be justified.

Adult

Early Transcriptional Changes in Neutrophil-Mediated Processes Following Recanalization After Ischemic Stroke.

BACKGROUND: Ischemic stroke is a leading cause of death and long-term disability worldwide. Recanalization therapies, including thrombolysis and mechanical thrombectomy, restore blood flow, yet many patients experience poor outcomes, a phenomenon known as futile recanalization. Given the short therapeutic window for ischemic stroke, identifying early biomarkers to guide targeted interventions and improve outcomes is critical. METHODS: Using a murine middle cerebral occlusion model that mimics a large vessel occlusion with recanalization, a comprehensive microarray analysis from blood samples collected immediately and 3 hours after recanalization (N=44) was performed. Differentially expressed genes, enrichment pathways, immune cell proportions, enriched cell markers, predicted micro-RNAs, and transcription factors were identified using RStudio. Findings in mice were validated with rat middle cerebral artery occlusion (GSE21136) and patients with stroke (GSE16561) data sets to confirm transcriptional changes in peripheral blood postrecanalization. RESULTS: Il1r2, Cd55, Mmp8, Cd14, and Cd69 were early biomarkers poststroke and postrecanalization. Cross-validation revealed Vcan as a differentially expressed gene conserved across species, making it a novel ischemic marker detected as early as 3 hours postrecanalization (4 hours after middle cerebral artery occlusion) in mice, 24 hours after recanalization in rats (middle cerebral artery occlusion-thrombectomy), and within 24 hours from onset in humans receiving recombinant tissue plasminogen activator-thrombolysis. CIBERSORTx and ImmuCellAI-mouse deconvolution showed neutrophil elevation postrecanalization. Leukocyte and neutrophil activation pathways were enriched early after stroke in mice and humans, with stronger upregulation in the female sex. Several regulatory micro-RNAs were identified, and Nuclear Factor Erythroid 4 (NFE4) and Metal Regulatory Transcription Factor 1 (MTF1) emerged as key transcription factors. A coregulatory network underlying neutrophil activity was constructed, highlighting its central role in early responses to ischemia and recanalization, which was enriched in the female sex. CONCLUSIONS: We identified novel early genomic markers for ischemia and recanalization, including the conserved marker Vcan, and highlighted age- and sex-specific immune responses. Mapping a neutrophil-centered coregulatory network provides mechanistic insight into futile recanalization and supports the development of targeted therapies to improve clinical outcomes.

Animals

[A prospective study to determine the recanalization time with a guide wire/recanalization catheter system in arterial occlusions].

The success rate and time taken for recanalization was determined in a prospective study of 82 consecutive unselected patients (53 men, 29 women; mean age 65.7 +/- 13, from 28 to 88 years). There were 106 complete occlusions of infrarenal arteries and a hydrophilic guide wire with a special 5-F recanalization catheter was used. Mean occlusion length was 12.97 +/- 10 cm (from 1 cm-45 cm). 79.3% of occlusions were in the femoro-popliteal territory, 6.6% were iliac and 14.1% tibial. 101 of the 106 occlusions were recanalized (95.3%). Mean recanalization time was 120.8 +/- 228.1 s (from 1 s-1440 s), mean recanalization velocity was 0.11 cm/s. The majority of obstructions could be recanalized in less than one minute. The five occlusions which could not be recanalized were distal lesions in the superficial femoral artery and which were longer than 10 cm; two were calcified. There were no complications resulting from the recanalization apart from three perforations which were clinically not apparent. Consequent angioplasty proved successful in 78.1% of these patients.

Adult

In vitro laser recanalization of chronically occluded prosthetic grafts.

Polytetrafluoroethylene (PTFE) and Dacron grafts were implanted in canine femoral and carotid arteries using PTFE and Prolene suture, respectively. Arteries containing occluded grafts were explanted and laser recanalization was attempted in vitro. Laser recanalization was successful in 78% of PTFE grafts compared to 30% of Dacron grafts. Recanalization was complete (residual stenosis less than 5%) in opened PTFE grafts, whereas residual stenosis averaged 60% in recanalized Dacron grafts. PTFE graft/PTFE suture anastomotic tensile strength was unchanged after recanalization, while Dacron graft/Prolene suture anastomotic tensile strength decreased significantly. In addition, anastomotic bursting pressure was significantly higher for lased PTFE grafts with PTFE sutures (300 mg Hg) compared to lased Dacron grafts with Prolene sutures (70 mm Hg). Chronically occluded PTFE grafts with PTFE suture can be safely and effectively opened by laser recanalization. In contrast, attempted laser recanalization of Dacron grafts sutured with Prolene suture is seldom successful, significantly weakens the graft artery anastomosis, and should be avoided.

Anastomosis, Surgical

[Recanalization of occluded coronary arteries using the Magnum system].

Recanalization procedures with the "Magnum" system were undertaken in 137 patients (113 men, 24 women; mean age 57.1 +/- 8.1 years) with complete occlusion of a coronary artery. The system consists of a 0.021 inch guidewire with a flexible 1 mm diameter olive tip, a double-lumen probing catheter and a Magnarail balloon catheter. Chronic coronary artery occlusion of maximally 3 months was present in 51 patients (37%), for over 3 months in 52 (38%), while the duration of occlusion was unknown in 18 (13%). An acute coronary occlusion was successfully recanalized in 7 patients (5%), while in 9 (7%) it was accomplished when it had occurred during or shortly after a percutaneous coronary artery angioplasty (PCTA). The occlusion was successfully passed in 87 patients (64%); in 15 of them recanalization with another system had failed. The highest success rates were obtained with an acute occlusion (5 of 7; 71%), occlusion of 3 months' duration or less (39 of 51; 76%), and occlusion during PTCA (8 of 9; 89%). The success rates were lower for occlusions over 3 months' duration (25 of 52; 48%; P < 0.05) and of unknown duration (10 of 18; 56%; n.s.). Recanalization after failed recanalization was successfully accomplished by rotation-angioplasty (n = 2) or a standard system (n = 4).--These results indicate that the Magnum system is suitable for recanalizing chronic or acute coronary occlusion. But cardiologists should be capable of using several systems to increase the chances of successful recanalization.

Adult

Relationship between ophthalmic artery blood flow and recanalization of occluded carotid artery. Ultrasonic Doppler study.

Ophthalmic artery blood flow in 5 patients with internal carotid artery occlusion of sudden onset was monitored by an ultrasonic Doppler flowmeter to investigate the possible relationship to spontaneous recanalization of the occluded artery. The occluded internal carotid arteries of 2 patients were confirmed angiographically to recanalize and the reversed flow of their ophthalmic arteries changed to physiological flow after the recanalization. The ophthalmic artery blood flow remained reversed in 2 patients whose occluded internal carotid arteries did not recanalize on the follow up angiograms. In the other patient, whose ophthalmic artery blood flow was not detected by the ultrasonic Doppler flowmeter in the acute stage, physiological flow through the ophthalmic artery was detected later. The occluded internal carotid artery did not recanalize and this physiological ophthalmic artery blood flow was filled through the circle of Willis.

Acute Disease

Initial experience with transluminal recanalization of the recently occluded infarct-related coronary artery in acute myocardial infarction -- comparison with conventionally treated patients.

In 7 patients, the recently occluded infarct-related vessel was recanalized by transluminal catheter techniques during acute myocardial infarction (Group A). 4 patients had single-vessel disease, 2 patients two-vessels disease and one, involvement of three vessels. Control angiography was performed in 6 patients, 8 days to 7 months later. Changes of coronary artery anatomy and left ventricular function were compared with a group of 9 conventionally treated patients, who were found to have occlusion of the infarct-related vessel in the acute stage (Group B). Five Group B patients had one-vessel disease, 3 patients two-vessel disease and 1 patient, involvement of all three vessels. In the chronic stage, all transluminally recanalized vessels were found to be patent in Group A. There was spontaneous recanalization of the infarct vessel in 4 of 9 Group B patients. In Group A, the length of the akinetic segment (AKS) decreased significantly (p less than 0.05) from 145.4 +/- 48.5 mm to 73.2 +/- 73.4 mm (mean +/- SD). Volume parameters did not change significantly. In Group B, length of the AKS did not change significantly, EDVI increased significantly from 81.1 +/- 19.8 to 106.8 +/- 4.6 ml/m2 (p less than 0.05); ESVI increased significantly from 41.7 +/- 13.7; ml/m2 to 66.8 +/- 37.9 ml/m2 (p less than 0.01). In the acute stage, length of the AKS and volume parameters did not differ significantly between the two groups. In the chronic stage, AKS was significantly shorter (A: 73.2 +/- 63.4 mm; 144.9 +/- 59 mm (p less than 0.0025) and EF was significantly higher (A: 54.6 +/- 11.6%; B: 40.9 +/- 14.5% (p less than 0.05) in Group A. Peak CPK was lower in Group A (A: 1009 +/- 827 U/l; B: 1324 +/- 655 U/l), but this difference did not achieve statistical significance. Results of this pilot study suggest that transluminal recanalization in the early phases of acute myocardial infarction might result in limitation of myocardial injury. However, further research will be needed to improve the technique and to test its results.

Adult

Sanguineous cerebrospinal fluid in recanalized cerebral infarction.

To clarify the causal relationship between spontaneous recanalization of the occluded cerebral artery and development of hemorrhagic infarction, 15 patients with internal carotid or middle cerebral arterial axis occlusion were submitted to consecutive lumbar punctures and follow-up cerebral angiography. Consequently, six of seven recanalized patients had sanguineous cerebrospinal fluid (CSF) on the second or third day after ictus, while only one of eight non-recanalized patients had bloody CSF. It was strongly suggested that recanalization might have an initimate relationship with the development of hemorrhagic infarction.

Adult

Laser recanalization versus endoscopic intubation in the palliation of malignant dysphagia: a randomized prospective study.

Forty patients with histologically confirmed malignant dysphagia were randomized to either endoscopic intubation or laser recanalization. Age, sex, tumour histology and site were evenly distributed between the groups. Results were analysed on an 'intention to treat' basis. All patients treated by laser achieved patency; there was one failed intubation. The best swallowing grade achieved was significantly better with laser recanalization (median 4 (range 3-4)) than with intubation (median 3 (range 2-4)) (P < 0.001). The median survival was 21.5 (range 4-62) weeks in the group receiving laser treatment, compared with 14.5 (range 7-102) weeks in the intubated group (P = 0.09). The median inpatient stay as a proportion of survival time was 14 per cent in the group receiving laser treatment compared with 15 per cent in the intubated group (P > 0.05). The median weight loss was less in the laser-treated patients (2.0 (range 2-8) versus 3.0 (range 0-10) kg, P = 0.04). These results indicate that laser recanalization provides better palliation of dysphagia than does intubation, but this is not reflected in an improvement in survival time.

Adult

Acute coronary occlusion with impending infarction as an angiographic complication relieved by a guide-wire recanalization.

In a 45 year old male patient with a history of previous inferior myocardial infarction and unstable angina pectoris, coronary angiography revealed two-vessel disease: a 60-70% lesion in the middle third of the LAD, and a 90% lesion in the middle third of the very large RCA. There was only a small akinetic segment in the posterobasal region of the left ventricle. During angiography total occlusion of the RCA occurred followed the clinical and electrocardiographic signs of impending inferior reinfarction. Recanalization of the occluded vessel was accomplished by using a guide-wire, which was passed through a Sones catheter, placed in the RCA. The patient's symptoms subsided and the electrocardiographic signs of acute ischemia reverted within eight minutes. Aortocoronary bypass surgery with revascularization of the LAD and RCA was performed within 3 hours after recanalization. Postoperatively there was no evidence of major tissue loss by enzyme or electrocardiographic criteria. Control angiography, performed on the ninth day postoperatively, revealed the graft to the RCA to be widely patent. Left ventricular function was unchanged. It is concluded, that the combined approach of early transluminal recanalization of the acutely occluded RCA followed by successful construction of a graft to this vessel, has averted necrosis of a major portion of the left ventricle. However, general use of this technique does not seem advisable at the present time.

Acute Disease

Surgical recanalization of occluded peripheral arteries.

This article, reflecting on the surgical recanalization of occluded peripheral arteries, has exposed the very essence of vascular surgery. Only the pioneering cardiac anomalies repaired by Gross (patent duct arteriosus, 1938), Blalock and Taussig (tetralogy of Fallot, 1944), and Crafoord and Nylin (coarctation, 1945) and the legendary aortic grafting operations of Oudot (occlusion, 1950) and Dubost and coworkers (aneurysm, 1951) are not a part of this article. The contributions to surgical recanalization of the occluded peripheral arteries are numerous. Some are well conceived, and others are innovative. Perhaps the most significant technique of all, endarterectomy itself, began purely as a serendipitous event. The startling impact of dos Santos' revolutionaly "disobliteration" was realized at once. Intimal injury during the operation did not cause inevitable thrombosis, as historically taught. Thus, all vascular interventions, either endarterectomy, graft repair, or the newer endovascular techniques discussed in this issue, would not have been developed without the understanding of the tolerance of the human intima to injury. Thromboendarterectomy, the basis of surgical recanalization of occluded arteries, unlocked the mystery of arterial rethrombosis after intervention. Recognizing these crucial facts, it will have a lasting place in the expanded discipline of vascular disease and its treatment. Dos Santos, the European founder of endarterectomy, and Wylie, the American pioneer and proponent of endarterectomy, were great friends in life (Fig. 4) and would certainly be pleased to see the further development of technology aimed at the treatment of atherosclerotic obstruction of the peripheral arteries.

Arterial Occlusive Diseases

Ultrasound recanalization of diseased arteries. From experimental studies to clinical application.

At present, percutaneous peripheral ultrasound angioplasty should be considered in those patients with symptoms of claudication or resting limb ischemia. With the development of an over-the-wire system, we treat patients with suprageniculate or infrageniculate lesions. It is expected that the over-the-wire probe will allow application of ultrasound angioplasty not only to lesions below the knee but to contralateral vascular occlusions as well. An intraoperative device for plaque ablation and arterial recanalization is in development for use in less accessible sites such as the coronary arteries. Experimental studies have shown that catheter-delivered therapeutic ultrasound recanalizes complete occlusions, reduces stenoses, dissolves thrombus, vasodilates, and enhances arterial distensibility. The potential clinical applications of therapeutic ultrasound include recanalizing total arterial occlusions, dissolving thrombi, facilitating balloon angioplasty by increasing arterial compliance, and as a stand-alone angioplasty device.

Angioplasty, Balloon

Positive scans in angiographically proved cases of recanalized cerebral infarction.

In 20 patients with acute major cerebral arterial occlusion, follow-up angiograms were obtained to inspect the occluded artery. These angiograms were compared with brain scans in the fourth week after the stroke. The angiograms revealed that frequent recanalization of the occluded arteries occurred within a week after the onset. On the other hand, brain scans showed the increased uptake of radioisotopes even in the patients with angiographically demonstrated arterial recanalization. The present study clarified that positive scans could be obtained in the patients with and without recanalization, and emphasized the diagnostic value of brain scans in the subacute or chronic stage of cerebral infarction, especially in patients with no arterial occlusion appearing on the angiograms.

Acute Disease

Transcervical fallopian tube recanalization: a safe and effective therapy for patients with proximal tubal obstruction.

Over a 13-month period, 14 patients with proximal tubal obstruction underwent transcervical fallopian tube recanalization under fluoroscopic guidance in an outpatient setting at the hospital of the University of Pennsylvania. Twenty-one of 24 attempted tubal dilations (87.5%) were successful, as demonstrated by tubal opacification and contrast spillage into the peritoneal cavity at the conclusion of the procedure. Four intrauterine pregnancies, and no ectopic pregnancies, have followed the recanalization. One pregnancy ended in an early miscarriage, one patient delivered a healthy term female, and two pregnancies are ongoing at greater than twenty weeks' gestation. Two procedure-related complications occurred: in one patient, the isthmic segment of a fallopian tube was perforated, but healed without incident, and another patient experienced a low-grade fever, which resolved with p.o. antibiotics. We therefore conclude that fallopian tube recanalization is a well-tolerated, safe, and effective procedure for the treatment of proximal tubal occlusion.

Adult

[Neodymium--Yag laser in the recanalization of arterial occlusions].

Failure of the guide-wire to recanalize some arterial total occlusion does not preclude balloon angioplasty. Nowadays there are recanalization devices such as the mechanical atherectomy and Lasers. The following report describes the successful use of the Nd: YG Laser in the recanalization of a common iliac artery total occlusion in a patient with claudication, rendering possible balloon angioplasty and a Palmaz Stent implantation, which is the first case performed in our country.

Aged

Intravascular ultrasound guided holmium:YAG laser recanalization of occluded arteries.

Current angioplasty devices are limited by arterial wall dissection and perforation, and by early recurrence from inadequate debulking of lesions. This study evaluated intravascular ultrasound (IVUS) as guidance for concentric laser recanalization of arterial occlusions. Twelve, 2-4-cm-long canine iliac artery occlusions were treated at 2 weeks (organizing thrombus) to 12 weeks (firm fibrous lesions) using a Holmium:YAG laser (2,100 nm wavelength) in free running mode, FRM, (250 musec pulse, 5 Hz), n = 9; and Q-switched mode, QSM (200 ns pulse, 6 Hz), n = 3. A 200 microns (n = 2) or 600 microns (n = 10) optic fiber was centered in the artery coaxial to a 5Fr rotating A scan IVUS probe. The fiber was positioned in the center of the artery distal to the lesion and slowly advanced through the obstruction. In 8 occlusions the same fiber was used as a guidewire for passage of either a 1.6-mm-(n = 2) and/or 3.0-mm (n = 6) diameter multifiber catheter (19 x 100 and 19 x 200 microns fibers, respectively) using FRM energy to further debulk the lesion. In all cases, IVUS guidance enabled concentric initial recanalization of occlusions, although 3 vessel perforations resulted from fiber deviation off the center of the lumen at a distance of 2 to 4 cm from the IVUS imaging element. Both QSM and FRM modes ablated tissue, with FRM modes producing more tissue fragmentation and thermal effect. IVUS images accurately diagnosed the location of lesions compared to angioscopic views and pathologic analysis of the specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Laser