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Step-by-Step Transcatheter Aortic Valve Replacement with a Self-Expanding Valve

Wednesday, May 25, 2022

Abri QA, Reardon MJ, C. Wyler von Ballmoos M. Step-by-Step Transcatheter Aortic Valve Replacement with a Self-Expanding Valve. May 2022. doi:10.25373/ctsnet.19858030 

This video offers a step-by-step approach to transcatheter aortic valve replacement (TAVR) using a self-expanding valve. It features the case of a patient at intermediate surgical risk who chose to undergo TAVR. Although many of the general principles and steps shown apply to the TAVR in general, this case specifically highlights the use of a self-expanding transcatheter valve. 

It is worth noting that the authors perform about 90 percent of their TAVR under monitored anesthesia care. General anesthesia is used when performing a surgical cut-down for alternative access TAVR, in certain high-risk patients, or when a transesophageal echocardiogram is warranted for intraprocedural imaging, among other reasons. The authors also use transcranial doppler ultrasound for neuromonitoring routinely.  

 

The Procedure 

First, all puncture sites are infiltrated with local anesthetic. Using ultrasound guidance and a micropuncture needle, the right jugular vein is accessed, and a tearaway sheath is place over a short J-wire. A transvenous pacing (TVP) wire is placed into the apex of the right ventricle. The capture threshold is checked down to 1mA to ensure good capture. Ultrasound guidance and a micropuncture needle are then used to identify the common femoral artery on the contralateral side of the TAVR access. A safe location above the bifurcation is identified and a 6 French (Fr) sheath is placed.  

In this video, the authors use a left internal mammary artery (LIMA) catheter and a Glidewire endoscopic guidewire to go across the aortic bifurcation into the opposite femoral artery. The Glidewire is exchanged for an .018 steel core wire (e.g., Platinum Plus), and the authors use this as a landmark for the access on the working side (TAVR access site). Importantly, this approach also facilitates quick access to the TAVR side in case of a major access complication. However, it’s important to note that, with a substantial reduction in the profile of TAVR delivery system, this is now less of a concern. Therefore, the authors do not cross over routinely anymore; however, in select cases (e.g., difficult access) this may still be useful.  

Next, an incision is made above the femoral artery on the TAVR side using the safety wire or vascular ultrasound as a guide. Blunt dissection is used to ensure the vascular closure device (ProGlide or Manta) will go down to the artery without difficulties. The key with this vascular access is to get a perfect anterior stick of the common femoral artery wall to ensure the closure device will work properly. This is done using a micropuncture technique with a microwire and microsheath. An arteriogram is then obtained to make sure the access is above the bifurcation but below the inferior epigastric artery. Based on patient criteria, the authors use either a single, large-bore closure device (Manta, Teleflex) or a preclose technique (ProGlide, Abbott) for access site closure. 

 

Using a J-wire, a 10 Fr dilator is advanced into the abdominal aorta. Then an Amplatz Super Stiff guidewire is advanced under direct vision to the proximal extent of the descending thoracic aorta. The large access sheath is then placed over the Amplatz wire after systemic heparin is given. Two checklists are used throughout the procedure to ensure all steps are followed. One is used after placement of the access sheath and the other before implanting the valve. A long J-wire is then placed through the 6 Fr sheath and a 5 Fr marker pigtail catheter is placed in the noncoronary cusp. A root angiogram is obtained in the cusp overlap (L/R) projection, which is now the preferred implantation view, as it isolates the noncoronary cusp and its transition to the R coronary cusp (N-R commissure) underneath which the conduction system runs. Furthermore, it stretches out the LVOT, as compared to the previously commonly used coplanar view, which in return foreshortens the LVOT, making gauging depth of implantation more difficult. These modifications in technique have helped reduce new conduction disturbances and the need for permanent pacemaker implantation. In the authors’ experience, this has resulted in single digit pacemaker incidence after TAVR.  

A J-wire and AL-1 catheter are then advanced through the TAVR sheath and positioned above the aortic valve to cross the latter. The valve is then crossed with a straight tip .035 wire and the AL-1 is then placed over the straight wire into the ventricle. The straight wire is then again exchanged for an exchange-length soft J-wire and a 6 Fr angled pigtail in the LV apex. This is hooked up to manometry for pre-TAVR hemodynamics. Here the surgeons pay attention to the heart rate, pressure gradient, and the LVEDP.  

A preimplant balloon valvuloplasty is then carried out, typically with a noncompliant balloon, sized to the patient’s anatomy. This is not always necessary but preferred when the valve is heavily calcified, and for all patients with bicuspid aortic valves. The transcatheter valve is then checked under fluoroscopy to make sure it has been loaded well before it is being deployed. A precurved, stiff wire such as the extended curve Lunderquist is then placed through the pigtail catheter in the LV, and the balloon for the valvuloplasty is brought into position and inflated under rapid ventricular pacing at a rate of about 180. The balloon is removed, and the valve is introduced. This is done either through the sheath or using the delivery system inline sheath. The valve orientation in the descending thoracic aorta is confirmed to optimize commissural alignment, and the arch is crossed in one smooth movement in an left anterior oblique (LAO) projection.  

The surgeons then return to the cusp overlap projection and carefully advance the transcatheter heart valve (THV) across the native valve. With the marker band centered at the pigtail catheter, care is taken to bring the capsule of the delivery system just to the bottom of the pigtail and deployment of the valve itself is begun. As the valve exits the sheath, ventricular pacing is started at 120–140 bpm to reduce the risk of being pushed too much into the aortic root. The valve is then deployed 80 percent, and at this point implant depth is assessed, but not PVL, as the valve is not yet fully deployed. The depth in the cusp overlap view is checked. Then the surgeons roll over to a 25 LAO position, removing parallax, to assess depth again. They then wait two to four minutes to let the nitinol expand. While doing that, an echo with a long-axis view is obtained to again gauge the depth both on the mitral side and the septal side.  

Once satisfied with the position, the surgeons release the valve. The nose cone is then carefully centralized to not dislodge the THV, and the delivery system is moved back into the descending thoracic aorta, recaptured, and removed. A root angiogram and hemodynamics are repeated to ensure no residual gradient or PVL. This is also confirmed by echo again using color doppler in both short- and long-axis. Subcostal 3- and 5-chamber views are helpful for this assessment. If those are satisfactory, protamine is given and the TAVR sheath is removed over wire with the dilator in place so that the ProGlide can slide down along the dilator.  

When using a preclose technique with a ProGlide, a Rummel tourniquet can be used for temporary hemostasis. After protamine has been in for about two minutes, we reassess the bleeding at the access site. Occasionally, a second ProGlide or a Angio-Seal (Terumo) is required to achieve sufficient hemostasis. A completion angiography of the access vessel is then performed to ensure normal flow and no other new pathology in the access vessel. If the patient has a normal rhythm and narrow complex with no new conduction abnormalities, the authors will also take the TVP out. Otherwise, the TVP is left in place overnight with a backup rate of 40 bpm and reassessment of TVP dependence the next morning. The patient is then taken to the post-anesthesia care unit for recovery. 


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