Artificial venous valves are considered the Holy Grail of chronic venous disease (CVD). It is believed that replacement venous valves would cure the most difficult-to-treat CVD conditions such as venous ulcers.
But what's taking so long to develop an artificial venous valve? And if we did have an artificial venous valve where would it be located and what types of patients would benefit?
These questions are addressed in an extensive article from Vein Magazine and can be accessed here:
https://www.veindirectory.org/magazine/article/techniques-technology/runnin-down-a-dream-a-round-table-discussion-on-artificial-vein-valves
The participants in the article (presented as a round table discussion) are many and include Thomas O'Donnell, Bob Kistner and Fedor Lurie. It would have been interesting to have Tony Comerota and Vito Mantese in the discussion but maybe next time.
First question, where would artificial venous valves be most useful? If you consider very simply that the venous system is made up of superficial veins, perforator and deep veins, then artificial valves would mostly target damaged or missing valves in the deep veins.
There are currently very effective options to treat the superficial and to a lesser extent perforator vein complications. Namely, endovenous laser treatment (EVLT) is used to close off superficial veins that are varicosed and diseased. The blood is able to route around these locations after they are sealed. For perforator veins, a procedure known as subfascial endoscopic perforator surgery (SEPS) has been used to cut and clamp diseased perforator veins. This procedure, however, has been mostly phased- out since it has not been shown to be very effective in treating CVD conditions.
There are very limited options to treat deep vein insufficiency. Yet, most of the major CVD complications such as venous ulcers are due to deep vein complications. The reason is because the deep veins are the main "highway" that carries approximately 80% of the blood back to the heart. The rest goes through the superficial system. Therefore, if there were a working artificial venous valve, it would be most effectively used in the deep vein system. What's surprising is that there are only 3 valves in the femoral popliteal vein segment and if one of those are faulty it results in a cascade of CVD conditions.
A problem that has plagued artificial venous valves is that they thrombose in the low pressure blood flow that occurs in the deep veins.