Search

Introduction : AFX is a bifurcated unibody aortic endograft for the treatment of Abdominal Aortic aneurysms. It consists of an inner metallic endoskeleton with multiple metallic struts covered by a polytetrafluoroethylene graft fabric. The endoskeleton is sutured to the outer fabric only at the proximal and distal ends. The unique design of AFX aims at fixation onto the aortic bifurcation while a proximal cuff ensures sealing at the infrarenal level. Areas covered : Since this endograft design by Endologix has undergone significant changes over the last years, the aim of this article is to present its unique structure and deployment method and discuss the relevant clinical results as well as reported complications and associated concerns. Expert commentary : the AFX stent-graft exhibits very satisfactory clinical mid-term results in abdominal aortic aneurysms treated within the instructions-for-use. Its 'active-seal' concept of infrarenal fixation stemming from the loose conjugation of the fabric material to the endoskeleton can accommodate efficiently to challenging necks with thrombus or morphological irregularities, thereby extending the anatomical sealing zone without exerting significant radial outward force. Long-term results are needed to validate the promising performance of AFX.

Introduction: Cardiovascular diseases such as coronary heart disease often necessitate the surgical repair using conduits. Although autografts still remain the gold standard, the inconvenience of harvesting and/or insufficient availability in patients with atherosclerotic disease has given impetus to look into alternative sources for vascular grafts., Areas Covered: There are four main techniques to produce tissue-engineered vascular grafts (TEVGs): i) biodegradable synthetic scaffolds; ii) gel-based scaffolds; iii) decellularised scaffolds and iv) self-assembled cell-sheet-based techniques. The first three techniques can be grouped together as scaffold-guided approach as it involves the use of a construct to function as a supportive framework for the vascular graft. The most significant advantages of TEVGs are that it possesses the ability to grow, remodel and respond to environmental factors. Cell sources for TEVGs include mature somatic cells, stem cells, adult progenitor cells and pluripotent stem cells., Expert Opinion: TEVG holds great promise with advances in nanotechnology, coupled with important refinements in tissue engineering and decellularisation techniques. This will undoubtedly be an important milestone for cardiovascular medicine when it is eventually translated to clinical use.

This article reviews the present state of small-diameter vascular substitution, the mechanisms of graft failure and the ongoing matters of graft design, with particular attention to small-caliber grafts. Tissue engineering of blood vessels with the mechanical properties of native vessels and with the antithrombotic properties required is really a great challenge. Recent advances, however, indicate that the goal of providing a tissue-engineered vascular graft that will remain patent in vivo for substantial periods of time, is achievable. This review describes the specific requirements of the successful replacement artery from a biomaterial- and tissue-engineering perspective, as well as various approaches in vascular tissue engineering including cells and cell sources, scaffolds and their improvements as well as bioreactors and signaling.

Cardiovascular-related syndromes are the leading cause of morbidity and mortality worldwide. Arterial narrowing and blockage due to atherosclerosis cause reduced blood flow to the brain, heart and legs. Bypass surgery to improve blood flow to the heart and legs in these patients is performed in hundreds of thousands of patients every year. Autologous grafts, such as the internal thoracic artery and saphenous vein, are used in most patients, but in a significant number of patients such grafts are not available and synthetic grafts are used. Synthetic grafts have higher failure rates than autologous grafts due to thrombosis and scar formation within graft lumen. Cell and gene therapy combined with tissue engineering hold a great promise to provide grafts that will be biocompatible and durable. This review describes the field of vascular grafts in the context of tissue engineering using cell and gene therapies.

This article reviews the clinical use of stents in the treatment of coronary artery disease and the rationale for the use of degradable, drug-eluting polymer stents. The authors note the challenges of using off-the-shelf polymers for the development of degradable stents, as well as the interplay between polymer properties and a functional stent design. Drug-eluting metal stents are the most significant advancement in the treatment of coronary artery disease, and have significantly reduced the occurrence of in-stent restenosis after placement. Some regard drug-eluting metal stents as the final technologic advancement in the treatment of coronary artery disease, others consider the future development of degradable, drug-eluting stents as the next logical step.

Currently, autologous veins are the first choice for patients in need of bypass grafting materials. However, due to either pre-existing conditions or previous bypass surgery, some patients lack the necessary amount of host tissue for such procedures. Unfortunately, current synthetic vascular grafts of less than 6 mm in diameter have been plagued by a variety of problems. For this reason, there has been significant research aimed at finding more suitable small-diameter vascular graft materials. In order to improve vascular cell functions on such synthetic materials, several techniques are currently under development that attempt to mimic the natural nanometer architecture of the vascular basement membrane. This review presents several processes including colloidal lithography, chemical etching, electrospinning and solid free-form fabrication that could play a role in the future of vascular nanostructured biomaterial development.