Treatment of a Failing Medtronic Freestyle Stentless Valve with Low Coronary Heights by Symetis ACURATE TA Valve-in-Valve Implantation

IntroductionValve-in-Valve (ViV) TAVI implantation for degenerated surgical valves is becoming increasingly common, especially with stented surgical bioprosthetic valves. However, ViV procedures are less frequent for stentless valves due to the additional risk from the lack of “landmark” stent ring with supporting posts and less standardized information about the aortic valvular complex. Also, several reports show higher rates of coronary obstruction in ViV due to the design limitations of the utilized surgical bioprostheses. We present the first case report of successful ViV with a second-generation transapical self-expanding valve, Symetis ACURATE TA, to treat a failing Medtronic Freestyle stentless valve for a patient with VERY LOW LYING coronary ostia.

Case PresentationIn 2002, the patient underwent CABG (SVG – RCA) and a modified, subcoronary stentless aortic valve replacement

PatIent data• 80 year-old fragile man• Multiple hospital admissions for CHF with

significant dyspnea on effort• Mild-moderate aortic stenosis and severe

aortic insufficiency• ES II: 14.4%, STS: 11.4%• Pmax/Pmean: 36/18 mmHg• NYHA class: III – IV• S/P Concomitant AVR/CABG with 25mm

Medtronic Freestyle Valve• Brittle diabetes – on insulin for over 30 years

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CASE STUdY

dr. Michael Chu, dr. Bob Kiaii, dr. Pantelis diamantouros and dr. Patrick TeefyWestern University, London Health Sciences Centre, London, ON, Canada

Medtronic Freestyle valve

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Transesophageal echocardiography (TEE): severe, transvalvular aortic regurgitation of a Freestyle valve

CASE STUdY

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Angiography: severe aortic regurgitation of a Freestyle valve

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Measurement of the height of the LCA ostium from the aortic annulus

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Measurement of the height of the RCA ostium from the aortic annulus

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Symetis ACURATE TA valve

with a 25 mm Medtronic Freestyle bioprosthesis. Although Freestyle porcine aortic roots (Fig 1) have been implanted with good hemodynamic results, durability has been linked to implantation technique (subcoronary vs. root replacement) and reoperation can be more challenging than after regular stented bioprosthesis1. TTE demonstrated severe structural valve deterioration of the stentless prosthesis with mild-moderate stenosis and severe aortic insufficiency with preserved LVEF (Figs 2 and 3). Pre-operative CT demonstrated an oval aortic annulus measuring 25 x 17 mm, 71 mm by perimeter and 331 mm2 by area. The aortic root

was narrow with a sinus to annular ratio of 1.2:1. LCA ostium height was 8.1 mm and RCA height was 6.3 mm (Figs 4 and 5). Cardiac catheterization confirmed a small, narrow aortic root with severe aortic insufficiency and a dilated left ventricle with grade I-II function. There was no significant disease in ungrafted LCA and 70 % RCA lesion with a patent vein graft.

Case Strategydue to the patient’s advanced age and comorbidities, TAVI was judged as the best treatment plan. However, coronary ostial heights of <10-12 mm and aortic sinus: annular ratio

Aortic Regurgitation

FreestyleTM

Length: 8.1 mm

Length: 6.3 mm

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CASE STUdY

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Small ACURATE TA positioning

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Small ACURATE TA deployment

<1.25:1 are considered contraindications for conventional transcatheter valves. Therefore we decided to employ the Symetis ACURATE TA valve (Fig 6)3-5. This bioprosthesis has a unique nitinol self-expanding stent design with an upper crown that engages the calcified native aortic valve and compresses it towards the aortic annulus, holding calcified leaflets away from the coronary ostia. The lower crown has a robust skirt and the hourglass shape facilitates self-seating and self-sealing, which is associated with very low rates of paravalvular (PV) leak3-5. These characteristics of ACURATE TA were considered key factors to optimize the fit within the failing Freestyle bioprosthesis.

“In addition to the upper crown holding calcified leaflets away from the ostia,

importantly, there is also tactile feedback during implantation. This can be critical in a degenerated Freestyle prosthesis,

where calcification can be sparse or difficult to visualize.”

Dr. Michael Chu - Western University, London Ontario, Canada

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Final angiographic result confirming an appropriate position of the ACURATE TA valve in the absence of aortic insufficiency

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TTE: no evidence of residual aortic regurgitation in the color Doppler

London Health Sciences Centre has been at the forefront of medicine in Canada for 139 years and offers the broadest range of specialized clinical services in Ontario. As a leader in medical discovery and health research, London Health Sciences Centre was the first in North America to implant ACURATE™ devices and has a history of over 65 international and national firsts.

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References1. Mohammadi S, Kalavrouziotis d, Voisine P, dumont E, doyle d, Perron J, et

al. Bioprosthetic valve durability after stentless aortic valve replacement: The effect of implantation technique. Ann Thorac Surg. 2014 Jun;97(6):2011-8.

2. Amabile N, Bical OM, Azmoun A, Ramadan R, Nottin R, deleuze PH. Long-term results of freestyle stentless bioprosthesis in the aortic position: A single-center prospective cohort of 500 patients. J Thorac Cardiovasc Surg. 2014 Feb 26.

3. dvir d, Webb JG, Bleiziffer S, Pasic M, Waksman R, Kodali S, et al. Transcatheter aortic valve implantation in failed bioprosthetic surgical valves. JAMA. 2014 Jul;312(2):162-70.

4. Kempfert J, Mollmann H, Walther T. Symetis ACURATE TA valve. EuroIntervention. 2012 Sep;8 Suppl Q:Q102-9.

5. Kempfert J, Treede H, Rastan AJ, Schonburg M, Thielmann M, Sorg S, et al. Transapical aortic valve implantation using a new self-expandable bioprosthesis (ACURATE TA): 6-month outcomes. Eur J Cardiothorac Surg. 2013 Jan;43(1):52,6; discussion 57.

take away messages• Low coronary clearances of <10 mm can

be treated with a newer-generation TAVI prosthesis that engages aortic calcification and pulls it away from the coronary ostia.

• Thanks to its tactile feedback, the ACURATE TA can treat a degenerated subcoronary implanted Freestyle prosthesis, while minimizing PV leak.

CASE STUdY

3d-CT reconstruction of the ViV construct and its position in the aorta

The information and statements in this document reflect the author’s personal clinical experiences and opinions. Symetis does not accept responsibility for any use that may be made of these materials. Medtronic, Medtronic Freestyle are registered trademarks of Medtronic, Inc.

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mean and peak gradients of 12 mmHg and 23 mmHg, respectively (Figs 9, 10, 11 and 12).The patient did well post-operatively and was discharged home on POd 6 without complication. At 3 months follow-up, he was doing well with no dyspnea (NYHA I) and significant improvement in his quality of life. Transthoracic echocardiography demonstrated a well functioning bioprosthetic aortic valve with no aortic insufficiency and a mean and peak gradient of 15 and 30 mmHg, respectively.

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ResultsPrior to implantation, a coronary guide wire was delivered to the distal LAd through a guide catheter for rapid access to the left coronary system in case of obstruction (Fig 7). A small (21-23 mm) ACURATE TA valve was inserted trans-apically. The upper crown of the Symetis valve was opened just above the annulus to engage the degenerated Freestyle leaflets and pulled slightly ventricularly before releasing the lower crown and sealing skirt to fully deploy the prosthesis (Figs 7 and 8). Post-procedural assessment confirmed an excellent result after ViV implantation with no residual aortic insufficiency and

TAVI Heart Team