Challenging Transfemoral Valve-in-Valve Implantation in a Degenerated Stentless Bioprosthetic Aortic Valve

ABSTRACT: Bioprosthetic heart valves are often preferred over mechanical valves as they may preclude the need for anticoagulation. Reoperation is the standard treatment for structural failure of bioprosthetic valves; however, it carries significant risk especially in inoperable elderly patients. Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) seems to be an effective and promising procedure in patients with degenerated bioprosthetic aortic valves avoiding the risks associated with the use of cardioplegia and redo cardiac surgery. We report an interesting case of a high-risk 74-year-old patient with a degenerated Sorin Freedom Solo stentless valve treated successfully with ViV TAVR.

J INVASIVE CARDIOL 2014;26(8):E106-E108

Key words: aortic stenosis, transcatheter aortic valve replacement, valve-in-valve, degenerated stentless valve, Sorin Freedom Solo

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Transcatheter aortic valve replacement (TAVR) is a novel procedure for the treatment of patients with severe symptomatic aortic stenosis (AS) at prohibitive or high operative risk for conventional surgical valve replacement (sAVR). TAVR improves survival and quality of life in patients at prohibitive surgical risk with severe AS and is comparable to sAVR in patients at high surgical risk.^1,2 Likewise, valve-in-valve (ViV) TAVR has been evolving as an effective and promising procedure, avoiding the risks associated with the use of cardioplegia and redo cardiac surgery in high-risk patients with degenerated bioprosthetic aortic valves.^3,4

Bioprosthetic heart valves are often preferred over mechanical valves as they may preclude the need for anticoagulation with its associated risks of bleeding and thromboembolism. However, bioprosthetic valves undergo structural deterioration over time and eventually fail.^5-7 Reoperation is the standard treatment for structural failure of bioprosthetic valves; however, it carries significant risk, especially in inoperable elderly patients. Patients with degenerated bioprosthetic valves are often elderly, with multiple cormobidities, and thus at high risk. Herein, we report an interesting case of a high-risk patient with a degenerated Sorin Freedom Solo stentless aortic valve treated successfully with ViV TAVR.

Case Report. A 74-year-old male patient with severe bioprosthetic aortic valve regurgitation was urgently admitted to our hospital due to advanced congestive heart failure, pleural effusions and ominous pulmonary edema not responding to high doses intravenous furosemide, and pleural drainage. Due to borderline respiratory function, he was intubated and transferred to the intensive care unit. His past medical history included sAVR due to severe aortic stenosis 9 months ago. In particular, he had a successfully supra-annularly implanted stentless bioprosthetic aortic valve (Sorin Freedom Solo, 23 mm) combined with coronary artery bypass grafting (left internal mammary artery [LIMA] to left anterior descending [LAD] artery and saphenous vein graft to the first oblique marginal artery). The first 5 months post procedure, he was generally well. However, he was diagnosed with severe aortic valve insufficiency (3/4+) due to dysfunction of the bioprosthetic valve at 6 months after the operation. Echocardiography showed that at least one of the leaflets was flail and incompetent. Although endocarditis was ruled out by negative blood cultures, he was empirically treated formally for endocarditis with no improvement. Thereafter, he had multiple hospitalizations due to acute heart failure and pulmonary edema and had pleural effusions drained on a number of occasions. Recent transthoracic and transesophageal echocardiographic (TEE) examination confirmed severe bioprosthetic valve insufficiency (4/4+), almost entirely transvalvular, due to dysfunctional/flail leaflet(s). Also, he had moderate mitral valve regurgitation, pulmonary hypertension (systolic pulmonary pressure, 55 mm Hg), moderate left ventricular (LV) failure with estimated LV ejection fraction 40%-45%, and mild LV dilatation (end-diastolic diameter, 61 mm) (Figures 1A, 1B, and 1C). He had a history of chronic renal disease (estimated glomerular filtration rate, 39 mL/min/1.73 m²) and microischemic encephalopathy. Logistic EuroSCORE was 41.6%, STS mortality score 5.5%, and the STS mortality and morbidity score was 37.6%. The patient was previously turned down for reoperation at another institution. Our hospital heart team also considered the patient to be inoperable, and we proceeded with urgent ViV-TAVR. 

The procedure was performed in our hybrid room with the patient placed in supine position and under general anesthesia and TEE guidance. Antibiotics were administered intravenously and intravenous heparin 50 U/kg was administered, targeting an activated clotting time of 250 seconds before valve implantation. Access to the right common femoral artery and vein was obtained. A temporal pacing wire was introduced in the apex of the right ventricle. Access to the contralateral femoral artery was obtained and it was preclosed with three Proglide devices. A 16 Fr eSheath (Edwards Lifesciences) was introduced. Before ViV implantation, coronary angiography confirmed that both grafts were patent and functional.

Under constant TEE guidance and short rapid cardiac pacing (160-200 bpm), a  29 mm CoreValve was successfully implanted on the third attempt. The CoreValve appeared to be mainly anchored in the native annulus except a small arc that was slightly above it, but still below the prosthetic valve annulus. Two previous attempts were unsuccessful due to lack of definitive anchoring points and movement of the CoreValve up to the ascending aorta. The interesting part of this procedure was that the implantation guidance was mainly by TEE, as there were no calcium landmarks and the native annulus was lower to the prosthetic valve annulus (Figure 2). Following valve implantation, the result was checked by angiography and TEE. The acute hemodynamic, angiographic, and TEE results were satisfactory. The valve position was stable, the systemic diastolic pressure increased from 28 to 56 mm Hg, with a mild to moderate paravalvular regurgitation (PVR) originating from the area of the CoreValve arc captured between the native and the bioprosthetic valve annuli (Figures 1D, 1E, and 1F). After sheath removal and Proglide closure, the peripheral entry integrity was checked by angiography. The fluoroscopy time was 45:59 minutes, dose area product was 536.627 mGy cm², and the volume of contrast agent was 125 mL. Postoperatively, the patient was transferred to the intensive care unit, where he was extubated 14 hours later without neurological or other major complications (according to VARC definitions). After 3 days, the patient was transferred to normal station and was discharged on day 7. His convalescence at home remained uneventful; he returned to full activity soon thereafter, with full recovery of his renal function and a clear chest x-ray on day 15. He remained well at 2-month follow-up.

Discussion. We present an interesting case of a patient with severely degenerated stentless bioprosthetic aortic valve who was successfully treated with ViV TAVR. Unlike stented bioprosthetic valves, a stentless valve has no rigid metallic ring for the anchoring of the new prosthesis and no visual landmarks to guide its positioning. This valve type has certain technical characteristics that make such a procedure very demanding. Therefore, the risk of malpositioning was considered relatively high and implantation of a retrievable device, such as CoreValve, was in our case the preferred choice. Moreover, the best ViV position would be one that achieves sealing at the annulus level and at the same time apposition of the degenerated valve leaflets preventing their overhang. This would be difficult with a Sapien XT prosthesis, which in addition would not find a “hard” substrate for anchoring.

When pushed away by the newly implanted valve, Sorin Freedom Solo leaflets can act similar to a covered stent, increasing the risk for coronary ostia obstruction (a risk shared by all stentless aortic valves). In a recent Global ViV Registry, Sorin Freedom Solo had the highest rate of coronary obstruction (50%; 3/6 cases) per type of surgical valve, suggesting that certain surgical bioprostheses may increase the risk of coronary obstruction in the setting of ViV-TAVR.⁸ The Sorin Freedom Solo has very elongated leaflets with a height of 31.5 mm (Figure 2). In our case, this was not a limitation since the left main was protected by a patent and well matured LIMA graft to the LAD.

Bioprosthetic valve dimensions are of great importance in choosing the correct size for ViV. Internal diameter (ID) for the same labeled valve size varies between manufacturers. This is the most critical dimension that determines the correct size of transcatheter valve to use for achieving complete sealing of the old prosthesis.⁹ The leaflet and frame heights should also be considered in degenerated stentless valves. In our case, according to ID of the Sorin Freedom Solo prosthesis (21 mm), a 26 mm CoreValve device could be the correct choice. However, based on multislice computed tomography annulus measurements (aortic valve mean annulus, 25 mm; perimeter, 87.6 mm; area, 503 mm²), we opted to use a 29 mm CoreValve. 

Positioning of the valve was successfully achieved by using optimal fluoroscopic aortic root delineation for the CoreValve release, but mainly by TEE guidance since there were no angiographic marks and the native and the prosthetic valve annuli did not concur. However, we had to retrieve the CoreValve prosthesis twice due to failure of grasping at the annulus level and jumping up in the ascending aorta. On our third attempt, we clearly aimed lower in the native annulus for grasping, but when the valve opened almost at its 2/3, it was still moving freely in the LV outflow tract. Upon slow withdrawal, it finally stabilized with most of its distal margin grasped by the native annulus, except a small arc that was grasped higher but below the prosthetic valve annulus. Better control and stabilization of the prosthesis was assisted greatly by faster rapid pacing during our third successful attempt (200/min instead of the earlier 160/min).

Recently, it was demonstrated that elderly patients may undergo ViV-TAVR without mortality, although these series probably represented small numbers of highly selected cases from expert institutions.¹⁰ A common problem was modestly-elevated gradients across the new transcatheter valve, suggesting blockage in flow and prosthesis-prosthesis mismatch.⁹ Therefore, new TAVR devices dedicated for ViV procedures should be developed, enabling treatment even of smaller bioprosthetic valves with improved efficacy and safety.

In conclusion, transcatheter ViV replacement in stentless bioprothetic aortic valves is a feasible, however technically demanding, procedure. Thorough knowledge of the aortic valve area anatomy and the prosthetic valve characteristics, as well as extensive meticulous planning, are essential for a successful procedure. TEE guidance in the absence of fluoroscopic landmarks is of paramount importance. For these reasons, ViV procedures should be undertaken at experienced centers.

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From the Department of Transcatheter Heart Valves, Hygeia Hospital, Athens, Greece.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted September 30, 2013, provisional acceptance given November 22, 2013, final version accepted December 4, 2013.

Address for correspondence: Konstantinos Spargias, MD, THV Department, Hygeia Hospital, 9 Red Cross Street, 151 23, Athens, Greece. Email: kspargias@hygeia.gr