Step-by-Step Transcatheter Aortic Valve Replacement with a Self-Expanding Valve
This video demonstrates our approach to transcatheter aortic valve replacement (TAVR) using a self-expanding valve. This is a case of a patient at intermediate surgical risk who chose to undergo TAVR after visiting our multidisciplinary valve clinic and shared decision making. The focus of this video is on a step-by-step description of the TAVR procedure. Although many of the general principles and steps shown here apply to the TAVR in general, this case specifically highlights the use of a self-expanding transcatheter valve.
We now perform about 90% of our TAVR under monitored anesthesia care (MAC). General anesthesia is used when we perform a surgical cut-down for alternative access TAVR, in certain high-risk patients, or when TEE is warranted for intra-procedural imaging, among other reasons.
We also use TCD for neuromonitoring routinely now. 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 sheath is placed. At the time of the recording of this video, we used a LIMA catheter and a Glidewire to go across the aortic bifurcation into the opposite femoral artery. The Glidewire would be exchanged for an .018 steel core wire (e.g. Platinum Plus), and we would 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. With a substantial reduction in the profile of TAVR delivery system this is now less of a concern. We do not cross over routinely anymore; 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 micro sheath. An arteriogram is obtained to make sure the access is above the bifurcation but below the inferior epigastric artery. Based on patient criteria we use either a single, large-bore closure device (Manta, Teleflex) or a pre-close technique (Proglide, Abbott) for access site closure.
Using a J-wire a 10 French dilator is advanced into the abdominal aorta. Then an Amplatz Super Stiff wire is then 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. We use 2 checklists throughout the procedure to ensure all steps are followed. One is used after placement of the access sheath, 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 prefer implantation view as it isolates the non-coronary 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 co-planar view, which in return foreshortens the LVOT, making gauging depth of implantation more difficult. These modifications in technique have helped with reducing new conduction disturbances and the need for permanent pacemaker implantation. In our 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 later. 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 French angled pigtail angled pigtail in the LV apex. This is hook up to manometry for pre-TAVR hemodynamics. Here we pay attention to the heart rate, pressure gradient and the LVEDP. A pre-implant balloon-valvuloplasty is then carried out, typically with a non-compliant 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 pre-curved, 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, 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 LAO projection. We then return to the cusp overlap projection, and carefully advance the THV across the native valve. With the marker band centered at the pigtail catheter we make sure to bring the capsule of the delivery system just to the bottom of the pigtail and we start to deploy the valve itself. as the valve exits the sheath, we start ventricular pacing at 120-140 bpm to reduce the risk of being pushed too much into the aortic root. The valve is then deployed 80% and at this point we assess implant depth, but not PVL as the valve is not yet fully deployed. We check the depth in the cusp overlap view and roll over to a 25 LAO position, removing parallax, to assess depth again. We then wait 2 to 4 minutes to let the nitinol expand. While doing that we obtain an echo with a long-axis view to again gauge our depth both on the mitral side and the septal side. Once satisfied with the position, we 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 we are happy with this, 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 pre-close technique with a Proglide, a Rummel tourniquet can be used for temporary hemostasis. After protamine has been in for about 2 minutes we re-assess the bleeding at the access site. Occasionally, a second Proglide or a Angioseal (Therumo) is required to achieve sufficient hemostasis. A completion angiography of the access vessel is then performed to ensure normal flow and not other new pathology in the access vessel. If the patient has a normal rhythm and narrow complex with no new conduction abnormalities, we will also take the TVP out. Else, the TVP is left in place overnight with a backup rate of 40bpm and re-assessment of TVP dependence the next morning. The patient is then taken to the PACU for recovery.