Vascular valves and servovalves - and simplified vascular bypass heart transplantation

A perivascular valve for encircling a blood vessel of a pediatric patient, the perivascular valve comprising:

• a valve body and, the valve body defining an integral tubular blood outlet passageway sidestem extending perpendicularly from said valve body, the outlet passageway being continuous with a lumen of the blood vessel,
• wherein the perivascular valve is selectively positional, such that the perivascular valve with sidestem can be positioned at any anatomically available level and rotational angle along the blood vessel,
• wherein the outlet passageway comprises a driven polymeric tongue having an upturned front end configured as a blood outflow diversion chute which is extendable a controllable distance into the lumen of the blood vessel so as to draw off a controllable volume of blood between zero and one hundred percent into said passageway for discharge through the outlet passageway sidestem,
• wherein the valve body comprises a stretchable material comprising expandable furrows to allow radial expansion of the perivascular valve so as to accommodate growth in the pediatric patient.