(A) Examination of the anastomosis: the vein at the anastomosis will be slightly aneurysmal, and a very forceful pulse will be felt. The thrill will be present only in systole and may be very short and even difficult to detect.
(B) Examination of the stenotic zone: as the palpating finger moves up the vein away from the anastomosis, the pulse goes away rather abruptly. The onset of the stenosis can also frequently be palpated as an abrupt diminution in the size of the vein, almost like a shelf. Above this level (downstream), the pulse is very weak and may be difficult to detect.