Computationally Designed 3D Printed Self-Expandable Polymer Stents with Biodegradation Capacity for Minimally Invasive Heart Valve Implantation: A Proof-of-Concept Study

Background Transcatheter valve-in-ring strategies have been developed to treat recurrent mitral regurgitation (MR) after failing surgical annuloplasty. However, suboptimal THV expansion with consecutive paravalvular leakage (PVL) is a procedure-immanent issue. Methods A rigid, saddle-shaped ring was cut at four locations. The segments were reconnected with pull-springs, rearranged to the original shape, and covered with a sewing cuff. The length of the annuloplasty ring construct, including extended pull-springs, was defined by the perimeter of an appropriate THV. We deployed a Sapien XT within the new ring, expanded it to its maximum extent, and investigated the geometrical changes. Results Fluoroscopy confirmed oval, saddle-shaped ring before dilation. After THV implantation, the ring segments spread apart and pull-springs were stretched. The extended ring changed its configuration from “oval” to “round” and anchored the THV leaving no paravalvular or central gaps as potential source for PVL. Conclusion We developed an expandable annuloplasty ring that is perfectly concerted to THV implantation. This proof-of-concept study revealed no PVL and good oversizing ability that might impact future annuloplasty ring design. Further studies have to evaluate durability and device safety.

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TCT-275 First-in-Man Transfemoral Stent-in-Valve Implantation as Bail-Out for Failed Transcatheter Heart Valve Implantation: Proof of Concept

Journal of the American College of Cardiology ◽

10.1016/j.jacc.2021.09.1128 ◽

2021 ◽

Vol 78 (19) ◽

pp. B112-B113

Author(s):

Won-Keun Kim ◽

Holger Nef ◽

Yeong-Hoon Choi ◽

Christian Hamm

Keyword(s):

Heart Valve ◽

Proof Of Concept ◽

Transcatheter Heart Valve ◽

Valve Implantation ◽

Bail Out

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Abstract 5839: Living Tissue Engineered Heart Valves Based On A Composite Self-Expandable Sandwich-Structured Scaffold And Autolgous Adult Stem Cells: First In Vivo Experiences Towards A Complete Minimally Invasive Approach

Circulation ◽

10.1161/circ.118.suppl_18.s_1013-b ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Doerthe Schmidt ◽

Christine Mariani ◽

Arja Puolakka ◽

Marja Rissanen ◽

Jens Kelm ◽

...

Keyword(s):

Minimally Invasive ◽

Heart Valve ◽

Adult Stem Cells ◽

Heart Valves ◽

Heart Valve Tissue ◽

Tissue Engineered Heart Valves ◽

Valve Implantation ◽

Cell Harvest ◽

Composite Self

Background : A clinically relevant heart valve tissue engineering concept requires minimally invasive techniques for both cell harvest and valve implantation. Here, we present first experiences with autologous tissue engineered heart valves fabricated from composite self-expandable biodegradable scaffolds and adult stem cells implanted by minimally invasive procedures in a sheep model. Methods : Sandwich-structured heart valve scaffolds (n= 12) were fabricated from non-woven PLDLA meshes coated with electrospun PLDLA nanofibers and integrated in self-expanding nitinol stents. Scaffolds were seeded with either autologous ovine bone marrow (BMC; n= 4) or jugular vein-derived cells (JVC; n= 8) and cultured in bioreactors. After 9d, heart valves were endothelialized with autologous peripheral blood-derived endothelial progenitor cells and jugular vein-derived endothelial cells, respectively. After additional 3d, heart valves (n= 6) were implanted trans-apically in pulmonary position. Controls were analysed (n= 6) as to tissue formation and composition (histology, biochemical assays). Mechanical properties were determined by tensile tests. In vivo performance was assessed by echocardiography up to 4 weeks. Results : Histology revealed cell attachment and ingrowth into the scaffold material resulting in layered tissues with endothelialized, eNOS positive surfaces. Amounts of GAG and cell number were similar in all heart valves, comparable to native tissues. Collagen production was higher in BMC based heart valves compared to JVC-derived tissues (Hydroyproline amount 34% vs. 20% of native tissues). Mechanical profiles demonstrated physiological tissue strength (max. tensile stress 0.41± 0.21 MPa) but less elasticity (E-Moduli 1.89± 0.79 MPa) independent of the cell source. Echocardiography displayed in vivo functionality (transvalvular mean pressure gradient 10.36± 3.17 mm/Hg) with more flexibility of BMC based heart valves leaflets. Conclusions : These results demonstrate that heart valve tissue engineering based on a minimally invasive technique for both cell harvest and valve implantation is feasible. This clinically relevant approach is currently investigated in long-term animal studies.

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