Sutureless inflow cannula assembly for connecting ventricular assist devices to human circulation
An inflow cannula assembly intended for connecting a ventricular assist device (VAD) to a heart chamber without suturing anastomosis is provided. The inflow cannula assembly includes a deformable flow cannula with funnel-shaped bellmouth intake at a first end and a second end interfaced to the inlet of a VAD with minimal interface discontinuity; also includes is a pair of male and female fasteners that can be screw locked to fix and seal the cannula bellmouth against the endocardium for hemostasis purpose; as well as a VAD coupler and a VAD inlet adapter that enable a quick connection of the cannula with the VAD.
1. An inflow cannula assembly, for transporting blood between a heart chamber and a ventricular assist device (VAD), comprising:
a deformable polymeric cannula, wherein the cannula includes:
a first end, with a bellmouth intake to be inserted into heart chamber;
a second end, with a flange ramp; and
a conduit, wherein the first and second ends are integrally joined by the conduit, and the entire inner surface of the cannula is smooth and seamless;
a pair of male and female fasteners, wherein the male and female fasteners are screw interconnected with the male fastener anchored on the cannula;
a ventricular assist device (VAD) coupler having a sandwiched flange base and a pair of collars pinned on the sandwiched flange base; and
a ventricular assist device (VAD) inlet adapter having a beak flange,
wherein the second end is configured to interface with the VAD inlet adapter, and the VAD coupler connects the second end with the VAD inlet adapter;
wherein the beak flange is accepted by the VAD coupler, and the collars have at least one internal grooved slot to receive and compress the sandwiched flange base, the flange ramp of the cannula, and the beak flange of the VAD inlet adapter; and
wherein the VAD inlet adapter further includes a wedge-shaped beak to be interfaced with the second end and a base configured to be integrated with the VAD.
2. The inflow cannula assembly as claimed in claim 1 , wherein the bellmouth has a gradually thinning wall thickness toward its tip, and the tip is sharp-edged.
3. The inflow cannula assembly as claimed in claim 1 , wherein an overlay portion of the conduit is configured to be in contact with cored myocardium is roughened so as to promote cell and tissue ingrowth for hemostasis and immobilization purposes.
4. The inflow cannula assembly as claimed in claim 1 , further comprising a female fastener cap configured to be in contact with an epicardium, wherein the female fastener cap is coated with a porous material.
5. The inflow cannula assembly as claimed in claim 4 , further comprising a Nitinol stent, such that the female fastener cap is supported by the Nitinol stent so as to generate a spring load when locked on the epicardium, allowing the female fastener cap be always attached on the epicardium.
6. The inflow cannula assembly as claimed in claim 1 , wherein the beak of the VAD inlet adapter and the second end are interfaced over the flange ramp, with the inner diameter of the beak slightly larger than the inner diameter of the conduit, wherein an interface surface of the flange ramp is inclined generally 30 to 60 degrees to a centerline of the cannula.
7. The inflow cannula assembly as claimed in claim 1 , wherein the VAD coupler includes an anti-decoupling latch and a collar contour that catches simultaneously onto the entire peripheral rim of the sandwiched flange base to assure a concentric coupling between the second end and the inlet adapter of the connected VAD.
8. The inflow cannula assembly as claimed in claim 1 , further comprising a stent embedment disposed in the cannula wall.
9. The inflow cannula assembly as claimed in claim 8 , wherein the stent is made of Nitinol material.
10. The inflow cannula assembly as claimed in claim 8 , wherein the stent has a zig-zag ring structure, and the stent is distributed over regions covering the bellmouth and the conduit.
11. The inflow cannula assembly as claimed in claim 8 , wherein the stent includes a plurality of arrays of zig-zag rings, wherein the arrays of zig-zag rings having a tubular shape being disposed in the conduit and a cone-shaped array of zig-zag rings disposed in the bellmouth.