sirolimus and Carotid-Stenosis

Carotid endarterectomy has demonstrated its superiority over medical treatment of symptomatic as well as asymptomatic stenosis of the extracranial carotid artery. Although minimally invasive methods initially failed to produce similar results, stent implantation is becoming an alternative technique for stroke prophylaxis with technical advances, cerebral protection and careful patient selection. Even though restenosis does not seem to be a major limitation compared to coronary interventions, in-stent restenosis might occur more frequently with an increasing number of procedures performed and longer follow-up periods. Drug eluting stents have shown to attenuate this complication. Currently, no clinical data on drug eluting stents in carotid arteries are available. This article discusses the current literature on carotid artery stenting and the potential role of drug eluting stents in this field.

Topics: Antineoplastic Agents, Phytogenic; Blood Vessel Prosthesis Implantation; Carotid Stenosis; Coated Materials, Biocompatible; Humans; Immunosuppressive Agents; Paclitaxel; Prosthesis Design; Secondary Prevention; Sirolimus; Stents; Stroke; Treatment Outcome

Fully absorbable polymeric scaffolds, as a potential alternative to permanent metallic stents, are entering the clinical field. The aim of this study is to assess the in vivo biocompatibility of a novel Sirolimus-eluting (SIR) absorbable scaffold based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB) for interventional application.. Absorbable PLLA/P4HB scaffolds either loaded with SIR coating or unloaded scaffolds were implanted interventionally into common carotid arteries of 14 female. Bare metal stents (BMS) served as control. Peroral dual anti-platelet therapy was administered throughout the study. Stented common carotid arteries segments were explanted after 4 weeks, and assessed histomorphometrically.. The absorbable scaffolds showed a decreased residual lumen area and higher stenosis after 4 weeks (PLLA/P4HB: 6.56 ± 0.41 mm² and 37.56 ± 4.67%; SIR-PLLA/P4HB: 6.90 ± 0.58 mm² and 35.60 ± 3.15%) as compared to BMS (15.29 ± 1.86 mm² and 7.65 ± 2.27%). Incorporation of SIR reduced the significantly higher inflammation of unloaded scaffolds however not to a level compared to bare metal stent (PLLA/P4HB: 1.20 ± 0.19; SIR-PLLA/P4HB: 0.96 ± 0.24; BMS: 0.54 ± 0.12). In contrast, the BMS showed a slightly elevated vascular injury score (0.74 ± 0.15), as compared to the PLLA/P4HB (0.54 ± 0.20) and the SIR-PLLA/P4HB (0.48 ± 0.15) groups.. In this preclinical model, the new absorbable polymeric (SIR-) scaffolds showed similar technical feasability and safety for vascular application as the permanent metal stents. The higher inflammatory propensity of the polymeric scaffolds was slightly reduced by SIR-coating. A smaller strut thickness of the polymeric scaffolds might have been a positive effect on tissue ingrowth between the struts and needs to be addressed in future work on the stent design.

Topics: Absorbable Implants; Angioplasty, Balloon; Animals; Cardiovascular Agents; Carotid Artery, Common; Carotid Stenosis; Inflammation; Materials Testing; Models, Animal; Polyesters; Prosthesis Design; Sirolimus; Sus scrofa; Time Factors

Topics: Aged; Angioplasty, Balloon; Cardiovascular Agents; Carotid Artery, Internal; Carotid Stenosis; Drug-Eluting Stents; Humans; Male; Plaque, Atherosclerotic; Prosthesis Design; Severity of Illness Index; Sirolimus; Treatment Outcome

A 43-year-old woman was diagnosed with moyamoya disease (MMD) and underwent right-side bypass surgery. After surgery, previous symptoms disappeared. One month later, transient right hemiparetic attacks and motor dysphasia developed. Angiography revealed progressive severe stenosis of left supraclinoid segment of internal carotid artery. Angioplasty using a drug-eluting stent (DES) was performed. For 18 months, she presented no ischemic symptom and no instent stenosis was observed in follow-up angiography. This is the first case report about effect of DES use for MMD. Considering that intimal hyperplasia is a pathophysiology of stenosis, DES may have a role in reducing progression of stenosis in selected moyamoya patients.

Topics: Adult; Angioplasty, Balloon; Carotid Stenosis; Cerebral Infarction; Drug-Eluting Stents; Everolimus; Female; Humans; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Moyamoya Disease; Paresis; Platelet Aggregation Inhibitors; Sirolimus

Intimal hyperplasia produces restenosis (re-narrowing) of the vessel lumen following vascular intervention. Drugs that inhibit intimal hyperplasia have been developed, however there is currently no clinical method of perivascular drug-delivery to prevent restenosis following open surgical procedures. Here we report a poly(ε-caprolactone) (PCL) sheath that is highly effective in preventing intimal hyperplasia through perivascular delivery of rapamycin. We first screened a series of bioresorbable polymers, i.e., poly(lactide-co-glycolide) (PLGA), poly(lactic acid) (PLLA), PCL, and their blends, to identify desired release kinetics and sheath physical properties. Both PLGA and PLLA sheaths produced minimal (<30%) rapamycin release within 50days in PBS buffer. In contrast, PCL sheaths exhibited more rapid and near-linear release kinetics, as well as durable integrity (>90days) as evidenced in both scanning electron microscopy and subcutaneous embedding experiments. Moreover, a PCL sheath deployed around balloon-injured rat carotid arteries was associated with a minimum rate of thrombosis compared to PLGA and PLLA. Morphometric analysis and immunohistochemistry revealed that rapamycin-loaded perivascular PCL sheaths produced pronounced (85%) inhibition of intimal hyperplasia (0.15±0.05 vs 1.01±0.16), without impairment of the luminal endothelium, the vessel's anti-thrombotic layer. Our data collectively show that a rapamycin-loaded PCL delivery system produces substantial mitigation of neointima, likely due to its favorable physical properties leading to a stable yet flexible perivascular sheath and steady and prolonged release kinetics. Thus, a PCL sheath may provide useful scaffolding for devising effective perivascular drug delivery particularly suited for preventing restenosis following open vascular surgery.

Topics: Animals; Cardiovascular Agents; Carotid Artery Injuries; Carotid Stenosis; Cell Proliferation; Chemistry, Pharmaceutical; Delayed-Action Preparations; Disease Models, Animal; Drug Carriers; Hyperplasia; Kinetics; Linear Models; Male; Neointima; Polyesters; Rats; Rats, Sprague-Dawley; Sirolimus; Solubility; Technology, Pharmaceutical

Topics: Angioplasty, Balloon; Cardiovascular Agents; Carotid Stenosis; Drug-Eluting Stents; Humans; Sirolimus

To evaluate the safety and efficacy of a balloon-mounted drug-eluting stent (DES) for recurrent carotid in-stent stenosis (ISS).. As part of our targeted carotid artery stenting (TARGET-CAS) protocol, neurological and ultrasound evaluations have been performed at 3, 6, and 12 months and then annually since 2001 in all carotid stent patients. For angiographically-confirmed >70% ISS, balloon angioplasty was performed as a first-line treatment. Recurrent ISS was treated with a 4.0-mm zotarolimus-eluting coronary stent (ZES) that was postdilated according to intravascular ultrasound imaging. Among the 1350 neuroprotected CAS procedures performed between January 2001 and March 2011, there were 7 (0.52%) patients (5 men; ages 51-72 years), all neurologically asymptomatic, with >70% recurrent ISS that occurred at 5 to 11 months after the initial balloon angioplasty treatment for ISS.. ZES implantation under distal embolic protection was technically successful and uncomplicated. Angiographic stenosis was reduced from 84.6%±7.5% to 10.7%±3.6% (p<0.01). In 5 patients with ZES implanted fully within the self-expanding carotid stent, duplex ultrasound follow-up (mean 17 months, range 6-36) revealed no evidence of restenosis or stent fracture/deformation. In the 2 other patients, the ZES had been implanted for distal edge ISS such that the ZES protruded beyond the original carotid stent. This protruding segment of the ZES demonstrated deformation/kinking in both; in one, this led to symptomatic stent occlusion.. The use of coronary ZES in the treatment of recurrent carotid ISS is feasible and appears effective provided the ZES is placed entirely within the original stent. Placement of a coronary ZES outside the carotid stent scaffold should be avoided.

Topics: Aged; Angioplasty, Balloon; Cardiovascular Agents; Carotid Stenosis; Drug-Eluting Stents; Embolic Protection Devices; Female; Humans; Male; Middle Aged; Poland; Prosthesis Design; Recurrence; Severity of Illness Index; Sirolimus; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Duplex; Ultrasonography, Interventional

Topics: Angioplasty, Balloon; Cardiovascular Agents; Carotid Stenosis; Drug-Eluting Stents; Female; Humans; Male; Sirolimus

Topics: Angioplasty, Balloon; Cardiovascular Agents; Carotid Stenosis; Drug-Eluting Stents; Female; Humans; Middle Aged; Recurrence; Sirolimus; Treatment Outcome

Topics: Angioplasty, Balloon; Cardiovascular Agents; Carotid Stenosis; Drug-Eluting Stents; Humans; Patient Selection; Recurrence; Sirolimus; Treatment Outcome; Ultrasonography, Doppler, Color

The use of bare metal stents to treat symptomatic intracranial stenosis may be associated with significant restenosis rates. The advent of drug-eluting stents (DESs) in the coronary circulation has resulted in a reduction of restenosis rates. We report our technical success rate and short-term restenosis rates after stenting with DESs in the intracranial and extracranial circulation.. This study was a retrospective review of the period between April 1, 2004, and April 15, 2006, of 59 patients with 62 symptomatic intracranial or extracranial atherosclerotic lesions at 2 medical centers (University of Pittsburgh and Borgess Medical Center).. The mean age of our cohort was 61+/-12 years. The location of the 62 lesions was as follows: extracranial vertebral artery 31 (50%), intracranial vertebral artery or basilar artery 18 (29%), extracranial internal carotid artery (ICA) near the petrous bone 5 (8%), and intracranial ICA 8 (13%). There were 2 (3%) periprocedural complications: 1 non-flow-limiting dissection and 1 disabling stroke. Fifty vessels were available for follow-up angiography or computed tomography angiography at a median time of 4.0+/-2 months. A total of 2 of 36 extracranial stents (7%) and 1 of 26 intracranial stents (5%) were found to have restenosis > or = 50% at follow-up.. This report demonstrates that DES delivery in the intracranial and extracranial circulation is technically feasible. A small percentage of patients developed short-term in-stent restenosis. Longer-term follow-up is required in the setting of a prospective study to determine the late restenosis rates for DESs in comparison with bare metal stents.

Topics: Anticoagulants; Aortic Dissection; Calcinosis; Carotid Artery, External; Carotid Artery, Internal; Carotid Stenosis; Catheterization; Cohort Studies; Drug Evaluation; Drug Implants; Feasibility Studies; Female; Follow-Up Studies; Humans; Ischemic Attack, Transient; Male; Middle Aged; Organ Specificity; Paclitaxel; Recurrence; Retrospective Studies; Sirolimus; Stents; Stroke; Vertebrobasilar Insufficiency

To present a patient in whom severe external carotid artery (ECA) stenosis causing ocular ischemia was treated with a drug-eluting stent.. A 55-year-old woman with severe, diffuse atherosclerosis presented with impaired left ocular perfusion and amaurosis fugax. Duplex ultrasonography and angiography documented bilateral occlusion at the origin of the internal carotid arteries, bilateral subtotal ECA stenoses, and subtotal distal left common carotid artery (CCA) restenosis following endarterectomy. Percutaneous revascularization of the left ECA and CCA stenoses was performed using a short coronary balloon-expandable sirolimus-eluting stent and a self-expanding nitinol stent, respectively. The procedure was uneventful, and the ocular symptoms resolved. At 6 months, the patient remained asymptomatic, with angiographically patent stents.. Drug-eluting stenting may be a novel option to treat symptomatic ECA stenosis.

Topics: Alloys; Amaurosis Fugax; Angiography, Digital Subtraction; Blood Vessel Prosthesis Implantation; Carotid Artery, Common; Carotid Stenosis; Coated Materials, Biocompatible; Endarterectomy, Carotid; Eye; Female; Humans; Immunosuppressive Agents; Ischemia; Middle Aged; Postoperative Complications; Reoperation; Sirolimus; Stents; Vascular Patency

Rapamycin, a macrolide antibiotic known to prevent allograft rejection, is a potent inhibitor of cell proliferation. Therefore we studied the effects of orally administered rapamycin in a pig model of balloon injury in an attempt to reduce the cellular proliferation and neointimal formation thought to play a role in restenosis. Twenty Yucatan minipigs, divided into groups of 10 animals each, were subjected to balloon inflation of the carotid arteries. One group received the methylcellulose vehicle for rapamycin, whereas the second group was treated for a total of 31 days with 2.0 mg/kg of rapamycin administered daily by oral gavage. This dose and treatment regimen produced significant (p < 0.05) reductions in neointimal area (59%) and in the maximal thickness of the neointima (59%) when comparisons were made with vehicle-treated animals. These effects were accompanied by a significant increase in the lumen area in animals that received rapamycin (33%). Medial area was decreased by 18% in these animals. Blood samples from rapamycin-treated pigs indicated peak concentrations of 1.87 +/- 0.45 and 1.70 +/- 0.24 ng/ml at 2 and 4 weeks after balloon angioplasty, respectively. Significant increases in blood pressure of 21 mm Hg and decreases in heart rate of 25 beats/min also were observed in rapamycin-treated animals relative to those that received vehicle. These results indicate that the antiproliferative effect of rapamycin can be demonstrated after oral dosing in a pig vascular injury model, suggesting a possible therapeutic utility for rapamycin or its analogs in patients undergoing balloon angioplasty.

Topics: Angioplasty, Balloon; Animals; Anti-Bacterial Agents; Blood Pressure; Carotid Arteries; Carotid Artery Injuries; Carotid Stenosis; Cell Division; Chromatography, High Pressure Liquid; Heart Rate; Lymphocytes; Male; Sirolimus; Swine; Swine, Miniature; Tunica Intima