Mitralign Percutaneous Annuloplasty System for the Treatment of Functional Mitral Regurgitation
aortic valve is crossed. A removable soft obturator, located at the tip of the guide catheter, aids the crossing of the aortic valve and ensures safe deflection of the guide catheter within the left ventricle. The catheter is deflected in order to be positioned over the posterior wall pointing up towards the mitral annulus. The obturator is then removed and the catheter is ready to swing between the papillary muscles. As a next step, the wire delivery catheter is advanced through and extended beyond the tip of the guide catheter so that it can be steered to a target point at the P1 or P3 scallop location of the annulus (see Figure 2A and B). Once a target point is selected and touched by the tip of the steerable catheter, a crossing wire is placed in a position ready to penetrate the annulus. The crossing wire is connected to an RF generator (Valleylab Force FX-C® Generator; Boulder, CO) and, by applying RF energy for one to two seconds, is advanced 1cm through the annulus and into the left atrium. The wire is then pushed deeply into the left atrium and pulmonary vein to provide better support for the next catheter and decrease the risk of losing position during the subsequent exchange of the wire-delivery catheter with the double-leg bident catheter. Prior to using the Bident catheter, one of the legs needs to be selected as a leading leg and loaded on the crossing wire. The catheter is tracked over the wire until the leading leg exits the guide catheter and is positioned in close proximity to the annulus. The second leg, which is collapsed in adjunction to the leading leg, is then pushed forward so that the catheter opens up in a bident configuration with a span of either 14 or 17mm between the legs. A second wire is delivered through the non-leading leg and penetrates the annulus with radiofrequency as described above (see Figure 3).
While maintaining the positioning of two wires, the Bident catheter is withdrawn and a pledget delivery catheter is advanced over each of the wires, one at a time. The pledget delivery catheter is pushed through the annulus until a radiopaque marker, indicating the exit port for the pledget, arrives above the annulus. Using a slide mechanism on the handle of the catheter, the atrial half of the pledget is pushed out of the catheter, and, subsequently, using a cinching wheel on the handle, this straight pledget portion is folded to a small piece (see Figure 4B). The wire is removed, and the pledget delivery catheter is pulled back in the guide catheter until the folded portion of the pledget remains on the atrial side of the annulus and the proximal straight portion of the pledget exits the pledget delivery catheter and the guide catheter. Using the cinching wheel on the handle, the proximal portion of the pledget is folded on the ventricle side of the annulus, and tightened to the atrial half of the pledget (see Figure 4B). When the pledget delivery catheter is withdrawn completely, the suture, which is attached to the pledgets, is freewheeled from the handle and exteriorised. A new pledget delivery catheter is tracked over the second wire to deliver a second pledget on the annulus. Once a pair of pledgets is implanted, the two sutures are exteriorised through the guide catheter and become a tracking rail for the plication catheter. This catheter is advanced up to the annulus so that the tip where the lock is located is positioned strictly underneath one of the pledgets. Using a plication assist device, tension is applied on both sutures and they are pulled together to achieve at least 50% plication. To secure the plication, the sutures are locked with the stainless steel lock. Finally, the plication catheter is exchanged with the suture cutter catheter, which cuts the sutures. Once the procedure is completed at one location (P1 or P3), a second pair of pledgets is delivered at the other scallop location (P3 or P1) and the plication is locked in place.
EUROPEAN CARDIOLOGY
Figure 5: Transoesophageal Guidance of Annulus Crossing with the Radiofrequency Wire
AB Crossing wire
Annulus Annulus
Pledget delivery catheter
A: The pledget delivery catheter; B: The crossing point on the annuls should be 1–2mm outside the hinging point of the leaflet but at least 1mm inside the myocardial wall.
Figure 6: Transoesophageal Guidance of the Guide Catheter Positioning on the Posterior Left Ventricular Wall
AB Guide Guide catheter catheter
The guide catheter needs to be deflected and positioned over the posterior wall. The tip of the catheter should not point to the posterior left ventricular (LV) wall (A) but needs to face the annulus (B).
Figure 7: 3D Transoesophageal Image of the Mitral Valve Demonstrates an Implanted Pledget on the Mitral Annulus
Implanted pledget
Echocardiographic Procedural Guidance Traditionally, percutaneous cardiovascular interventions have used angiographic and fluoroscopic guidance, which is limited when interventions involve the mitral valve.9
As percutaneous therapy for
mitral regurgitation continues to advance, it is inevitable that intraprocedural echocardiographic guidance will continue to evolve rapidly. TEE has been widely used as an alternative to transthoracic echocardiogram (TTE) in guiding complex procedures. TEE offers superior image resolution to TTE and excels at assessing anatomy and physiology, monitoring catheter position and performing dynamic evaluations to detect potential complications.10
A more recent
application of cardiac ultrasound, intra-cardiac echocardiography (ICE), may have considerable potential for monitoring and guiding mitral valve annuloplasty. However, experimental and clinical studies have to
69
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100