Endothelialization of coronary stents after intra-luminal adenoviral VEGF-A gene transfer in a preclinical porcine restenosis model - Studies with optical coherence tomography, angioscopy, multiphoton and scanning electron microscopy.

Background: Coronary stenting operations have become the main option for the treatment of coronary heart disease. Vessel recovery after stenting has emerged as a critical factor in reducing possible complications. In this study, we evaluated the feasibility, safety and efficacy of locally administered intraluminal gene therapy delivered using a specialized infusion balloon catheter.

Synthetic Flavonoid 3,7-Dihydroxy-Isoflav-3-Ene (DHIF) Reduces In-Stent Restenosis in an Atherosclerotic Watanabe Heritable Hyperlipidemic Rabbit Stent Model.

Inflammation is a major component of the pathogenesis of atherosclerosis and the formation of in-stent restenosis (ISR). A novel flavonoid, DHIF, attenuates reactive oxygen species and nf-κB signaling and has potential to limit ISR via antioxidant action. While current drug eluting stents (DESs) perform well in clinical practice, new therapies to prevent ISR without dependance on cytotoxic drugs are warranted.

Critical limb-threatening ischaemia and microvascular transformation: clinical implications.

Background And Aims: Clinical management of critical limb-threatening ischaemia (CLTI) is focused on prevention and treatment of atherosclerotic arterial occlusions. The role of microvascular pathology in disease progression is still largely unspecified and more importantly not utilized for treatment. The aim of this explorative study was to characterize the role of the microvasculature in CLTI pathology.

Evaluation of Biodegradable Stent Graft Coatings in Pig and Rabbit Models.

Aims: Percutaneous coronary intervention is routinely performed to treat occlusive coronary artery disease. Coronary perforation is a potential complication and can be treated with a stent graft. Current stent grafts are associated with high restenosis rates.

Serial Optical Coherence Tomography at Baseline, 7 Days, and 1, 3, 6 and 12 Months After Bioresorbable Scaffold Implantation in a Growing Porcine Model.

Background: Little is known about serial changes in lumen and device dimensions after bioresorbable scaffold implantation in a growing animal model.

Methods and results: ABSORB (n=14) or bare metal stents (ICROS amg [Abbott Vascular, Santa Clara, CA, USA], Winsen-Luhe, Germany; n=15) were implanted in the coronary arteries of domestic swine (a hybrid of Finnish-Norwegian Landrace swine) weighing 30-35 kg. Angiography and optical coherence tomography (OCT) were performed immediately after implantation and repeated at 7 days, 1, 3, 6 and 12 months after the index procedure.

Improved endothelialization of small-diameter ePTFE vascular grafts through growth factor therapy.

Background: Prosthetic vascular grafts in humans characteristically lack confluent endothelialization regardless of the duration of implantation. Use of high-porosity grafts has been proposed as a way to induce endothelialization through transgraft capillarization, although early experiments failed to show increased healing in man.

Objectives: We hypothesized that transduction of tissues around the prosthetic conduit with vectors encoding VEGF receptor-2 (VEGFR2) ligands would augment transinterstitial capillarization and induce luminal endothelialization of high-porosity ePTFE grafts.

Local adventitial anti-angiogenic gene therapy reduces growth of vasa-vasorum and in-stent restenosis in WHHL rabbits.

Background: Antiproliferative drugs in drug eluting stents (DES) are associated with complications due to impaired re-endothelialization. Additionally, adventitial neovascularization has been suggested to contribute to in-stent restenosis (ISR). Since Vascular Endothelial Growth Factors (VEGFs) are the key mediators of angiogenesis, we investigated feasibility and efficacy of local gene therapy for ISR utilizing soluble decoy VEGF receptors to reduce biological activity of adventitial VEGFs.

Biodegradable coronary scaffolds: their future and clinical and technological challenges.

Angioplasty and stenting are standard treatment options for both stabile occlusive coronary artery disease and acute myocardial infarctions. Over the last years, several biodegradable stent systems have entered pre-clinical and clinical evaluation and into clinical practice. A strong supporting scaffold is necessary after angioplasty to prevent elastic recoil of the vessel but in the long term a permanent metallic stent will only impair normal physiology of the artery wall.