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“Valve in valve” percutaneous aortic
valve implantation for severe mixed bioprosthetic aortic valve disease
Frederic De Vroey, Malcolm Legget, John Ormiston, Mark
Webster, James Stewart
Transcatheter aortic valve implantation (TAVI) is an
effective treatment for patients with severe aortic stenosis at high risk for
surgical valve replacement.
We present a case of successful, off-label transfemoral
valve-in-valve implantation of the self-expandable Medtronic-CoreValve
prosthesis in an inoperable elderly patient with structural deterioration of an
existing bioprosthesis in the aortic position.
Case report:A 76-year-old woman, with a past history of bicuspid aortic
valve and rheumatic fever, had undergone aortic valve replacement, with a size
21 Carpentier Edwards Perimount porcine pericardial bioprosthesis, 8 years
previously, for severe aortic stenosis. At operation, friability of the aorta
had been noted. In addition, the patient had smoking-related severe chronic
obstructive pulmonary disease (COPD), requiring intermittent systemic steroid
therapy.
She had become progressively more breathless over the
previous 12 months. Findings on clinical examination were consistent with severe
mixed aortic valve disease, and left ventricular failure. There was elevation of
N-terminal-brain natriuretic peptide (NT-ProBNP) at 145 pmol/L (normal <35),
suggesting a significant cardiac contribution to her symptoms.
Serial echocardiography had demonstrated gradual
degeneration of the porcine aortic valve prosthesis and, at presentation, there
was severe prosthetic valve stenosis (mean gradient of 24 mmHg, peak velocity of
3.1 m/sec, peak to peak gradient 30 mmHg, calculated valve area of 0.8
cm2), and, by standard Doppler
echocardiographic criteria, moderate aortic regurgitation due to prolapse of one
cusp. Left ventricular function had deteriorated with a reduction in
echocardiography-derived ejection fraction from 53% to 38% over the previous 6
months.
Given the patient’s severe COPD, fragile aorta, and
small aortic annulus, the risk of repeat aortic valve replacement was felt to be
prohibitive. The logistic EuroSCORE (European System for Cardiac Operative Risk
Evaluation) for perioperative mortality was 31% and STS (Society of Thoracic
Surgeons mortality risk) score was 40%. A multidisciplinary committee
recommended TAVI. Coronary and peripheral angiography showed trivial coronary
disease, an ascending aortic diameter of 42 mm and suitable iliac and femoral
arteries for a transfemoral approach.
Percutaneous aortic valve replacement was performed under
general anaesthesia, using a size 26 mm CoreValve ReValving system
(Medtronic-CoreValve, Irvine CA). This prosthesis consists of a self-expanding
nitinol frame with valve leaflets fashioned from porcine pericardial tissue,
delivered through a 18 F deployment catheter.
Delivery and deployment of the CoreValve were uncomplicated
(Figure 1) with an immediate reduction in the peak to peak gradient from 30 to 0
mmHg and trivial (Grade 1) aortic regurgitation. Echocardiography 3 days later
showed normal function of the percutaneous aortic valve, with a calculated valve
area of 1.3 cm2 and an improvement in left
ventricular ejection fraction to 53%. She remains well at 18 months with
significantly reduced dyspnoea and no need for a permanent pacemaker.
Figure 1. Shown in A is a frame from a cine
angiogram showing the Carpentier Edwards Perimount bovine pericardial aortic
bioprosthesis, In B, the sheathed CoreValve percutaneous valve prosthesis lies
across the degerated surgical prosthesis with a black arrow indicating the
marker on the distal end of the sheath. In C, the sheath (black arrow) has been
partially withdrawn allowing the nitinol frame to expand partially (White
arrow). In D the sheath has been largely withdrawn but is still attached to the
CoreValve nitinol frame (black arrow). In E, the CoreValve is fully released and
expanded.
![]() Discussion:The need for redo surgery due to structural valve
deterioration is approximately 10% at 10
years,1 depending on valve type and population
studied. Given the large number of tissue valves that have been implanted over
the last 20 years, there will be an increasing number of elderly patients with
multiple co-morbidities and bioprosthetic aortic valve deterioration.
Percutaneous aortic valve replacement will likely become an attractive
therapeutic option in this population.2,3
The ability to treat deteriorating prosthetic aortic tissue
valves percutaneously, may alter valve selection, especially in patients between
the ages of 60–70 years, in whom there is often a clinical dilemma as to
the optimal prosthesis, balancing valve durability against the need for
long-term anticoagulation.4
Percutaneous implantation of an aortic valve for degenerated
bioprostheses may be safer than repeat surgical aortic valve replacement for
native calcific aortic stenosis. First, precise percutaneous valve positioning
is facilitated by the radio-opacity of the bioprosthetic frame.
Second, previous surgical removal of the native heavily
calcified valve lessen the risk of underexpansion of the TAVI prosthesis and
subsequent paravalvular aortic leak, and reduces the risk of valve material
displacement covering a coronary ostium or inducing conduction disorder.
Similarly, there may be a role for balloon expandable valve implantation from
the transvenous or transapical routes for deteriorated mitral valve
bioprostheses.5
This case illustrates that TAVI for a deteriorated aortic
bioprosthesis is feasible in a patient who was not suitable for reoperation.
Long term studies are required before firm recommendations can be made regarding
the optimal treatment in this difficult patient group.
Author information: Frederic De Vroey
(Cardiologist)1; Malcolm Legget, (Cardiologist)
2,3; John Ormiston,
(Cardiologist)2,3; Mark Webster, (Director of
Interventional Cardiology)1,3; James Stewart
(Director Cardiology Department)1,2,3
Correspondence: Dr
Frederic De Vroey, Cardiology Department, Green Lane Cardiovascular Service,
Auckland City Hospital, Park Road 1023 Grafton, Auckland, New Zealand. Email: fredericd@adhb.govt.nz
References:
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