Venous valves rank among the smallest and most delicate organs of the human and animal bodies - so why devote an entire book to them? We were induced to do so by several reasons. First of all we would point out the clinical significance of venous valves. In the pathogenesis of a number of widespread diseases, such as varicose veins or the post-thrombotic syndrome, venous valves are involved as the underlying cause or at least a factor contributory to the symptoms. According to Taheri et al. these venous diseases occur ten times more frequently than arterial obliterations. Incompetence of...