Feasibility of a No-Implant Approach to Interatrial Shunts: Preclinical and Early Clinical Studies

Figures

• 

  Figure 1. Overview of the Alleviant procedure. (a) The tip of the device is advanced across the interatrial septum. (b) The tip of the device is opened to deploy the tissue anchoring mechanism within the LA. (c) The tip of the device is closed, thereby securing the target tissue, and a pulse of radiofrequency energy is applied to excise the tissue. Abbreviations: LA, left atrium; RA, right atrium.

• 

  Figure 2. Representative images of fresh interatrial shunt situated within the boundaries of the fossa ovalis across all timepoints (right atrial view). (a) Acute specimen shows the orifice edges appear rounded and expose the acutely sectioned tissue. (b) Thirty-day chronic shows surfaces of the shunt orifice edge and neighboring tissue appear smooth and glistening. (c) Sixty-day chronic shows a circular to mildly oval orifice with smooth edges.

• 

  Figure 3. Representative histologic sections across all timepoints. (a) Acutely cut posterior (left panel) and anterior (right panel) shunt edges present a tapered, rounded contour, with modest platelet/fibrin deposition in the anterior edge. A very thin band of coagulative changes (thermal effect) is also present in the myocardium adjacent to the cut (arrows, approximately 400 μm in depth). (b) Thirty-day shunt edges appeared rounded and fully healed, displaying fibrous remodeling and endothelialization. (c) Sixty-day sample (Movat) shows approximately 350 μm of collagen deposition at the rounded shunt edge, indicative of remodeling and normal healing. Stains: hematoxylin and eosin (top) and Movat (bottom); bar = 500 μm.

• 

  Figure 4. Representative images of 3D transesophageal echocardiographic assessment of interatrial shunt immediately following shunt creation in a human subject.

• 

  Figure 5. Representative images of transesophageal echocardiographic assessment of a human subject showing shunt patency sustained through 6-month follow-up. (a) Baseline, immediately post-shunt creation. (b) Six-month follow-up.

• 

  Figure 6. Representative images of cardiac computed tomography assessment showing shunt patency sustained through 6-month follow-up in a human subject. (a) Baseline, immediately postshunt creation. (b) Six-month follow-up.