The Art of SAPIEN 3 Transcatheter Mitral Valve Replacement in Valve-in-Ring and Valve-in-Mitral-Annular-Calcification Procedures

Abstract

The SAPIEN 3 is the only transcatheter heart valve commercially available for compassionate transcatheter mitral valve replacement in patients with previous mitral surgical rings and mitral annular calcification (valve in ring [VIR] and valve in mitral annular calcification [VIM]). Reported outcomes have been inconsistent or poor. The review provides an overview of the authors' approach to achieve largely consistent results despite the intrinsic limitations of SAPIEN 3 VIM and VIR. The approach includes bedside modifications of the valve implant, the delivery system, and of the cardiac substrate itself. Until purpose-built devices are readily available, VIR and VIM procedures will require aggressive multidisciplinary cooperation, meticulous planning and execution, and postprocedure management by experienced, high-volume operators.

Keywords: LAMPOON; SAPIEN 3; mitral annular calcification; transcatheter electrosurgery; transcatheter mitral valve replacement; valve-in-ring.

FIGURE 1. Left Ventricular Hypertrophy and MAC

Left ventricle in (A) diastole and (B) systole in a patient with severe mitral annular calcification (MAC) with severe left ventricular hypertrophy and mid-cavitary obstruction. Calcific aortic stenosis has been previously treated with transcatheter aortic valve replacement (TAVR). Ao = aorta; LA = left atrium.

FIGURE 2. Computed Tomography Analysis to Determine Landing Zone in Mitral Annular Calcification

(A) Different quadrants of calcification in a patient with mitral annular calcification (B) that are defined by placing virtual marker points at mitral leaflet insertion. The aortomitral curtain is colored purple. (C) The lateral commissure (LC) and medial commissure (MC) are depicted on the short axis.

FIGURE 3. Computed Tomography Before and After TMVR in Rigid and Compliant Landing Zones

Computed tomography analysis (A, C, E, G) before and (B, D, F, H) after transcatheter mitral valve replacement (TMVR) for valve in mitral annular calcification (MAC) and valve in ring. (A, C) In patients with a rigid landing zone, the TMVR is sized to the widest distance (often intercommissural distance) of the landing zone and area oversizing is minimal. (E, G) The SAPIEN 3 (S3) valve becomes noncircular in most cases. In patients with a nonrigid landing zone, the TMVR should be significantly oversized (>20%) compared with the area of the mitral annulus. The deployed S3 valve is circular and symmetrically expanded.

FIGURE 4. How to Place a Virtual Valve in the Landing Zone to Plan TMVR Procedure

The virtual valve is centered in the mitral short axis, then oriented along the left ventricular (LV) axis toward the apex, and finally, depth is adjusted so the external skirt of the SAPIEN 3 valve (7-8 mm) contacts the entire landing zone (usually 80% ventricular and 20% atrial). In this final position, neo-LV outflow tract (LVOT) and paravalvular leak (PVL) can be predicted. Ao = aorta; other abbreviations as in Figure 3.

FIGURE 5. Causes of Fixed and Dynamic LVOT Obstruction: Neo-LVOT, Skirt Neo-LVOT, and Long Anterior Leaflets

View from (A) 3-chamber and (B) Left ventricular outflow tract (LVOT) shows the difference between the resulting neo-LVOT and skirt neo-LVOT after transcatheter mitral valve replacement (TMVR). The skirt neo-LVOT is Larger and more basal with flow through the open cells of the SAPIEN 3 frame. (C) When the Length of the anterior mitral Leaflet is Longer than the height of the SAPIEN 3 TMVR (>22 mm), (D) the overhanging prolapsing Leaflet and associated Venturi effects may interfere with the SAPIEN 3 TMVR and (E) cause central mitral regurgitation. Tip-to-base LAMPOON (Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left ventricular Outflow tract ObstructioN) should be considered in these cases. LA = left atrium; LAA = left atrial appendage; LV = left ventricle; THV = transcatheter heart valve.

FIGURE 6. The Difference Between the Apical Trajectory and the Orthogonal Trajectory Measured Is the Emory Angle: Planning and Use of the Para-Apical Rail Decreases the Emory Angle and Improves Coaxiality

(A, B) Two examples of the Emory angle, measured as the angle between the centerline of the LV true apex (apical trajectory) and the mitral valve annulus centerline (orthogonal trajectory). A minor angulation should result in coaxial deployment of the SAPIEN 3 TMVR. (C, inset) More significant angulation (≥15°), results in poor coaxiality (dotted red lines do not match with solid green lines) when the SAPIEN 3 is deployed using a standard wire in the LV. (D) Correction of coaxiality (dotted red lines do match with solid green lines) results with SAPIEN 3 deployment along an LV rail. Cardiac computed tomography is used to plan percutaneous LV access to the mitral annulus centerline in both (E, G) the right anterior oblique (RAO) and (F, H) left anterior oblique (LAO) (or en face) projection. (E, F) The pre-procedure computed tomography angles, (G, H) bony landmarks such as ribs and coronaries help plan the trajectory. CAU = caudal; LAD = left anterior descending artery; LCx = left circumflex artery; MAC = mitral annular calcification; MV = mitral valve; RCA = right coronary artery; other abbreviations as in Figure 5.

FIGURE 7. LV Access, Completion, and Closure of Percutaneous Left Ventricular Rail

The needle (red bullseye) is directed (A) en face and (B) in right anterior oblique into the center of the mitral annulus. (C) The LV para-apical rail is completed by snaring the wire (blue line) using a transseptal snare in the aorta (orange petals). (D) The apex is closed using an Amplatzer Duct Occluder II 6/4 and a 0.014-inch safety wire. (dotted white line = MAC, solid green line = left anterior descending, dotted green line = LV). Abbreviations as in Figures 5 and 6.

FIGURE 8. LAMPOON and LAMPOON Variants to Modify Mitral Anterior Leaflet

(A, B) The antegrade technique is used instead of retrograde LAMPOON (intentional Laceration of the Anterior Mitral leaflet to Prevent left ventricular Outflow tract ObstructioN) for valve in mitral annular calcification. (C) For enhanced splay of the anterior leaflet, balloon-augmented LAMPOON may help. (D) The tip-to-base technique is used in which the aortomitral curtain is protected by a surgical device such as valve in ring. (E) For patients with previous Alfieri stitch or MitraClip, the ELASTIC or ELASTA-Clip techniques are used.

FIGURE 9. Preparation of S3 TMVR for POULEZ and Commissural Alignment

(A) The SAPIEN 3 (S3) is crimped on the balloon so that the pledgeted commissure (red asterisk) aligns to 12 o’clock and the suture is at 3 o’clock. (A) The suture passes through the nosecone with a stopper knot and (B) the other end passes through the pusher. (C, D) Traction on the suture deflects the trailing end of the SAPIEN 3 (S3) transcatheter mitral valve replacement (TMVR) much like 4-wheel steering on a fire truck causing (E) an exaggerated curve in the delivery system. This technique also helps orient (E) the “roll” (yellow arrow) of the S3 such that (E, F) the commissures of the TMVR (red dotted lines) (F) are not in front of the left ventricular outflow tract. Blue arrow = suture. Ao = aorta; LA = left atrium; LAA = left atrial appendage; POULEZ = Preparation of U-stitch to correct Lateral deflection for Endovascular mitral replacement in short landing Zone; RA = right atrium.

FIGURE 10. Fabric Skirts on the SAPIEN 3 to Improve Sealing

(A) The SAPIEN 3 has a shorter external fabric skirt (blue dotted line) (B) compared with the SAPIEN 3 Ultra (green dotted line). The Ultra is not commercially available in 29 mm. (C, D) The existing skirt can be augmented using polytetrafluoroethylene (blue and green dotted line). (E to H) The augmented skirt prevents paravalvular leak (red arrows and red flame) from geographic miss and allows more atrial deployment (yellow arrows = mitral annulus).

FIGURE 11. Use of Biplane Echocardiography and Catheter Maneuvers to Improve TMVR Coaxiality

Biplane transesophageal echocardiography can be used to determine (A) noncoaxial or (B) coaxial alignment before deployment in both the anteroposterior and mediolateral dimensions (orange line = mitral annulus, blue line = TMVR axis). (C) Thereafter, the x-ray projection angle can be adjusted orthogonal to the TMVR device without parallax (red box) pre-deployment. (C to E) The ventricular end of the TMVR will take the direction of the ventricular wire, while the atrial end of the TMVR is determined by the curvature of the delivery system (asterisk). These are positioned (C) by techniques including simultaneously pushing on both delivery system and delivery wire (push-push technique, mild deflection in delivery system), (D) by pulling a suture attached to deflect the nose cone (POULEZ technique, more extreme deflection of delivery system), or (E) by simultaneously pushing on the left ventricular apical rail and delivery system (red arrow = left ventricular sheath, more extreme deflection). AL = anterior mitral leaflet; AO = aorta; LC = lateral commissure; MC = medial commissure; PL = posterior mitral leaflet; other abbreviations as in Figure 9.

CENTRAL ILLUSTRATION. Key Considerations for TMVR (VIR and VIM) and LVOT Management Algorithm

(A) Key considerations for successful transcatheter mitral valve replacement (TMVR) valve in ring (VIR) and valve-in-mitral-annular-calcification (VIM) procedures. (B) The algorithm for left ventricular outflow tract (LVOT) management in TMVR VIM and VIR is based on computed tomography (CT) analysis. Important factors in the decision tree include neo-left ventricular outflow tract (LVOT) or skirt-LVOT, possibility of ventricular septal modification, and mitral leaflet length. Ao = aorta; LA = left atrium; LV = left ventricle; POULEZ = Preparation of U-stitch to correct Lateral deflection for Endovascular mitral replacement in short landing Zone; RF = radiofrequency; RV = right ventricle; SCHM-Ultra = Skirt Composed of High Molecular weight textile onto the SAPIEN 3 to resemble Ultra.