Ventricular assist device

In an implantable VAD including:

• (a) a pump,
• (b) a compliance chamber,
• (c) a tube connecting said pump and said compliance chamber in liquid and gaseous communication,
• (d) an outlet cannula connected to said pump at a proximal end and to graft tubing adapted to enter the aorta at a distal end,
• (e) a sewable flexible apical cuff adapted to be sewn to a heart,
• (f) a rigid tube adapted to enter a chamber of the heart, and
• (g) means for securing together said cuff and said rigid tube,
• the improvement comprising:
• (A) said compliance chamber forming:
• (i) a reservoir for liquid extending from adjacent the bottom of said compliance chamber upwardly towards the top of said compliance chamber;
• and
• (ii) a chamber for gas disposed above said liquid reservoir and extending upwardly to the top of said compliance chamber, said gas chamber being in gaseous communication with said pump via said tube;
• (B) a subcutaneous access port in liquid and gaseous communication with said liquid reservoir for introducing make-up gas into or removing excess gas from said gas chamber via said liquid reservoir and for removing accumulated liquid from said liquid reservoir;
• (C) conduit means connecting said port and said liquid reservoir in liquid and gaseous communication;
• (D) said outlet cannula comprising a hard polymer tubing commencing adjacent the pump and a relatively soft graft tubing adapted to be secured to the aorta, a distal end of said hard polymer tubing and a proximal end of said graft tubing being secured together by a snap-fit connector;
• and
• (E) said securing means including a collet defining multiple radially compressible circumferentially curved fingers, and a collar for radially inwardly moving said fingers to crimp a length of said cuff intermediate said collet and said rigid tube onto said rigid tube as said collar is rotated relative to said collet from an initial relative orientation.