Small-diameter vascular grafts for bypass surgery / 中国组织工程研究

ABSTRACT

OBJECTIVE: Small diameter vascular grafts (＜ 6 mm) are used predominantly in revascularization and reconstructive procedures. The small diameter vascular grafts already used in our clinical practice include autologous veins or arteries, polyethylene terephthalate (Dacron) and expanded polytetrafluoroethylene (ePTFE) synthetic vascular grafts. Unfortunately these vascular grafts all have some disadvantages that prohibit their uses. Therefore search for ideal small diameter vascular grafts has become the focus in recent years.DATA SOURCES A computer-based online search of Pubmed database was undertaken to identify the articles about small diameter vascular grafts published in English between January 1990 and January 2007 with the key words of "prosthetic graft, vascular bypass graft, small diameter vascular graft, tissue engineering".STUDY SELECTION The data were selected firstly to choose the full-text of articles met the criteria. Inclusion criteria ① Articles about biological vascular grafts; ②Articles about synthetic vascular grafts; ③Articles about small diameter tissue engineering blood vessels. Exclusion criteria Repetitive or analogical articles or case reports.DATA EXTRACTION Totally 113 articles on small diameter vascular grafts were collected and 41 met the inclusive criteria after eliminated the repetitive or similar studies or case reports.DATA SYNTHESIS: Although biological vascular grafts have the outstanding advantages, such as superior long-term patency, relatively resistant to infection, minimal thromboembolism, etc., they also have predominant disadvantages of limited availability, durability and aneurysm formation. Dacron and ePTFE are currently the standard synthetic vascular grafts in the vascular bypass surgery, but their immediate or long-term patency rates are relatively poor due to compliance mismatch, thrombogenicity and poor haemodynamics, especially when they are used in small diameter revascularization and reconstructive procedures. Thus, various modifications have been applied to Dacron and ePTFE grafts to improve their function. In recent two decades, the emergence of tissue-engineering technology has made the development of a novel biologically viable vascular substitute feasible, and it may prove to be the ultimate solution for better small-diameter vascular grafting.CONCLUCTION So far there is no completely biodegradable small diameter vascular graft suitable for the arterial circulation in humans. Construction of an ideal small-diameter vascular graft will require an interdisciplinary effort requiring critical contributions from biologists, engineers, and clinicians, with strong collaborations among these 3 fields being crucial to success.