The value of the patency test in microvascular anastomosis: correlation between observed patency and size of intraluminal thrombus: an experimental study in rats.

The value of the double forceps patency test in microvascular surgery is limited. It can only tell the surgeon if there is "some flow" or "no flow" through an anastomosis. An experimental study of microvascular anastomoses in the rat femoral vein and artery was designed to correlate the percentage reduction of the vessel luminal area with the clinical assessment of vessel patency. It was found that even with a proved thrombotic reduction of the luminal area by 75-95%, almost 50% of the anastomoses were classified as fully patent using the traditional patency test.