For 100 years, the process of vascular anastomosis has largely been the same. Surgeons take a needle and thread and delicately suture together the walls of the blood vessel. Though literally sewing together blood vessels is a widely utilized surgical procedure, it isn’t without its issues. Intimal hyperplasia, a cell response to the trauma of the needle and thread, causes blood vessels to narrow which increases the risk of a blood clot or localized turbulence. Sutures may trigger an immune response that causes dangerous inflammation. Moreover, suturing becomes extremely challenging on blood vessels that are less than one millimeter in diameter.
Microsurgeons at Stanford University have developed a new method of vascular anastomosis that is safer and faster. The key ingredient in this new process is Poloxamer 407, a unique, FDA-approved polymer whose properties can be reversed by heating. In the case of vascular anastomosis, Poloxamer 407 is injected at the site where the blood vessels are to be joined, and the area is heated. The unique properties of Poloxamer 407 cause it to become elastic and solid when heated above body temperature. This causes both openings of a severed blood vessel to become distended, allowing surgeons to precisely join the openings together with Dermabond, a commonly used surgical sealant. After the blood vessels have been joined, a decrease in temperature causes Poloxamer 407 to dissolve harmlessly into the bloodstream.
The process has been successfully demonstrated on blood vessels as small as 0.2 millimeters. If successful, the process could ultimately improve patient care by decreasing amputations, strokes and heart attacks while reducing health-care costs.
Press release from Stanford University: Stanford researchers invent sutureless method for joining blood vessels
Journal abstract in Nature Medicine: Vascular anastomosis using controlled phase transitions in poloxamer gels