Percutaneous aortic valve replacement (PAVR), also known as percutaneous aortic valve implantation (PAVI), transcatheter aortic valve implantation (TAVI) or transcatheter aortic valve replacement (TAVR), is the replacement of the
aortic valve
The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta. It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve. The ...
of the
heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...
through the blood vessels (as opposed to valve replacement by
open heart surgery
Cardiac surgery, or cardiovascular surgery, is surgery on the heart or great vessels performed by cardiac surgeons. It is often used to treat complications of ischemic heart disease (for example, with coronary artery bypass grafting); to corr ...
, surgical
aortic valve replacement
Aortic valve replacement is a procedure whereby the failing aortic valve of a patient's heart is replaced with an artificial heart valve. The aortic valve may need to be replaced because:
* The valve is leaky (aortic insufficiency, also known as ...
, SAVR). The replacement valve is delivered via one of several access methods: transfemoral (in the upper leg), transapical (through the wall of the heart), subclavian (beneath the collar bone), direct aortic (through a minimally invasive surgical incision into the aorta), and transcaval (from a temporary hole in the aorta near the navel through a vein in the upper leg), among others.
Severe symptomatic
aortic stenosis
Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the heart (where the aorta begins), such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse ove ...
carries a poor prognosis. At present there is no treatment via medication, making the timing of aortic valve replacement the most important decision to make for these patients. Until recently,
surgical aortic valve replacement was the standard treatment for adults with severe symptomatic aortic stenosis. However, the risks associated with surgical aortic valve replacement are increased in elderly patients and those with concomitant severe systolic
heart failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...
or
coronary artery disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pla ...
, as well as in people with comorbidities such as
cerebrovascular
Cerebrovascular disease includes a variety of Medicine, medical conditions that affect the blood vessels of the brain and the cerebral circulation. Arteries supplying oxygen and nutrients to the brain are often Angiopathy, damaged or deformed in ...
and
peripheral arterial disease
Peripheral artery disease (PAD) is an abnormal narrowing of arteries other than those that supply the heart or brain. When narrowing occurs in the heart, it is called coronary artery disease, and in the brain, it is called cerebrovascular diseas ...
,
chronic kidney disease
Chronic kidney disease (CKD) is a type of kidney disease in which a gradual loss of kidney function occurs over a period of months to years. Initially generally no symptoms are seen, but later symptoms may include leg swelling, feeling tired, vo ...
, and chronic respiratory dysfunction.
Overview
Patients with symptomatic severe aortic stenosis have a mortality rate of approximately 50% at 2 years without intervention. In patients who are deemed too high risk for open heart surgery, TAVR significantly reduces the rates of death and cardiac symptoms. Until about 2017 TAVR was not routinely recommended for low-risk patients in favor of surgical aortic valve replacement, however it is increasingly being offered to intermediate risk patients, based on studies finding that it is not inferior to surgical aortic valve replacement.
Transapical TAVR is reserved for patients for whom other approaches are not feasible: an evidence-based
BMJ Rapid Recommendation made a strong recommendation against ''transapical'' TAVR in people who are also candidates for either ''transfemoral'' TAVR or surgery.
[ Current as of October 2022. Has links to relevant BMJ papers.] People who have the option of either transfemoral TAVR or surgical replacement are likely to choose surgery if they are younger than 75 and transfemoral TAVR if they are older than 75.
The rationale for age-based recommendations is that surgical aortic valve replacements are known to be durable long-term (average of durability of 20 years), so people with longer life expectancy would be at higher risk if TAVR durability is worse than surgery.
Devices
Medtronic
Medtronic plc is an American medical device company. The company's operational and executive headquarters are in Minneapolis, Minnesota, and its legal headquarters are in Ireland due to its acquisition of Irish-based Covidien in 2015. While it ...
's CoreValve Transcatheter Aortic Valve is constructed of a self-expanding Nitinol frame and delivered through the femoral artery. This device received FDA approval in January 2014.
[Medscape]
"Transcatheter Aortic Valve Replacement Devices"
Retrieved December 2013.[
]Boston Scientific
Boston Scientific Corporation ("BSC"), incorporated in Delaware, is a biomedical/biotechnology engineering firm and multinational manufacturer of medical devices used in interventional medical specialties, including interventional radiology, in ...
's Lotus Valve system was awarded CE approval in October 2013. It allows the final position to be assessed and evaluated before release and has been designed to minimise regurgitation.
St Jude Medical
St. Jude Medical, Inc. was an American global medical device company headquartered in Little Canada, Minnesota, U.S., a suburb of Saint Paul. The company had more than 20 principal operations and manufacturing facilities worldwide with products s ...
's Portico Transcatheter aortic valve received European CE mark approval in December 2013. The valve is repositionable before release to ensure accurate placement helping to improve patient outcomes.[
]Edwards Edwards may refer to:
People
* Edwards (surname)
* Edwards family, a prominent family from Chile
* Edwards Barham (1937-2014), a former member of the Louisiana State Senate
* Edwards Pierrepont (1817–1892), an American attorney, jurist, and ora ...
' Sapien aortic valve is made from bovine
Bovines (subfamily Bovinae) comprise a diverse group of 10 genera of medium to large-sized ungulates, including cattle, bison, African buffalo, water buffalos, and the four-horned and spiral-horned antelopes. The evolutionary relationship betwee ...
pericardial tissue and is implanted via a catheter
In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Cath ...
-based delivery system. It is approved by the FDA for use in the US.[
]
Implantation
The devices are implanted without open heart surgery. The valve delivery system is inserted in the body, the valve is positioned and then implanted inside the diseased aortic valve, and then the delivery system is removed. The catheter based delivery system can be inserted into the body from one of several sites.
The transfemoral approach requires the catheter and valve to be inserted via the femoral artery. Similar to coronary artery stenting procedures, this is accessed via a small incision in the groin, through which the delivery system is slowly fed along the artery to the correct position at the aortic valve. A larger incision in the groin may be required in some circumstances.
The transapical approach sees the catheter and valve inserted through the tip of the heart and into the left ventricle. Under general anesthesia, a small surgical incision is made between the ribs, followed by a small puncture of the heart. The delivery system is then fed slowly to the correct position at the aortic valve. The puncture in the heart is then sutured shut.
The transaortic approach sees the catheter and valve inserted through the top of the right chest. Under general anesthesia, a small surgical incision is made alongside the right upper breastbone, followed by a small puncture of the aorta. The delivery system is then fed slowly to the correct position at the aortic valve. The hole in the aorta is then sutured shut.
The transcaval approach has been applied to a smaller number of patients who are not eligible for transfemoral, transapical, or transaortic approaches. In the transcaval approach a tube is inserted via the femoral vein instead of the femoral artery, and a small wire is used to cross from the inferior vena cava into the adjacent abdominal aorta. Once the wire is across, a large tube is used to place the transcatheter heart valve through the femoral vein and inferior vena cava into the aorta and from there the heart. This otherwise resembles the transfemoral approach. Afterwards, the hole in the aorta is closed with a self-collapsing nitinol
Nickel titanium, also known as Nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. Different alloys are named according to the weight percentage of nickel; e.g., Nitinol 55 and ...
device designed to close holes in the heart.
In the subclavian approach, an incision is made under the collarbone under general anesthesia, and the delivery system is advanced into the correct position in the aortic valve. The delivery system is then removed and the incision is sutured closed.
After-care
Regular medical checkups and imaging tests are required after TAVI.[
The Mayo Clinic says that blood thinners (]anticoagulants
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where the ...
) are prescribed to prevent blood clots after TAVI. Artificial heart valves are susceptible to bacterial infection; most bacteria that cause heart valve infections come from the mouth, so that good dental hygiene and routine dental cleaning are recommended. Antibiotics are prescribed for use before certain dental procedures.
New or worse post-procedure symptoms that require attention include dizziness or light-headedness, swelling of the ankles, sudden weight gain, extreme fatigue with activity, and signs of infection. Emergency attention is required for chest pain, pressure or tightness, severe, sudden shortness of breath, or fainting.[
]
Complications
When PAVR surgery is performed an important and difficult aspect that affects the patient is the orientation, uniformity and depth at which the valve is inserted. When the valve is not inserted correctly, when there is incomplete sealing between the native heart valve and the stented valve, paravalvular leak (PVL) can occur. Key properties associated with paravalvular leak are the regurgitation volume, the PVL orifice location (anterior or posterior) and the associated fluid dynamic effects that occur from the interactions between the regurgitated flow and the normal transmitral flow.
Morisawa ''et al.'' carried out quantitative research
Quantitative research is a research strategy that focuses on quantifying the collection and analysis of data. It is formed from a deductive approach where emphasis is placed on the testing of theory, shaped by empiricist and positivist philosop ...
to determine how the PVL flow effected normal transmitral flow based on three different in-vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called " test-tube experiments", these studies in biology and ...
situations: no PVL, anterior orifice PVL and posterior orifice PVL. The results showed that while the two PVL cases worsened the fluid dynamics of the normal transmitral flow seen without leakage, the posterior orifice PVL was worse, leading to a higher circulation and kinetic energy, requiring the heart to work harder and consume more energy to maintain normal bodily functions.
Prognosis
Recovery
A 2018 study that interviewed nineteen elderly patients six months after a transapical TAVI procedure found that participants felt weak and tired at first after TAVI, some more than before the procedure. Some reported a later "surprisingly simple rehabilitation" with rapid recovery, while others had a "demanding rehabilitation", with slow recovery, fatigue, and weakness.
Durability
The durability of transcatheter prostheses, in terms of all-cause mortality and the need of re-intervention, was not reliably known due to the lack of long-term follow-up data. A narrative review published in 2021 reported that a 2015 study involving simulation on first-generation prostheses suggested a TAVI durability limited to 7-8 years. Later prostheses have improved durability.
Bioprosthetic valve disfunction (BVD) has historically been divided into SVD (structural valve deterioration, including irreversible intrinsic changes of the prosthetic valve structure), NSVD (non-structural valve deterioration, including irreversible intra- or para-prosthetic regurgitation, prosthesis malposition, and patient-prosthesis mismatch), valve thrombosis, and endocarditis (which can be potentially reversible). Durability seems to be similar between TAVI and surgical implantation (SAVR), but there is a lack of long-term data, with only computed simulation models available. In many respects TAVI and SAVR are comparable, but TAVI still has a higher rate of NSVD. In elderly patients the prostheses should outlive the patient. The 2021 review suggested that in younger patients (with longer average life expectancy) choosing TAVI might still be premature, due to the increased likelihood of the need for future re-operation with worse prognostic impact.[
]
History
The catheter procedure was invented and developed in Aarhus University Hospital Denmark in 1989 by Henning Rud Andersen, who performed the first animal implantations that year. The first implantation in a human was performed on 16 April 2002 by Alain Cribier Alain Cribier, FACC, FESC (born 1945) is a French interventional cardiologist, who is a Professor of Medicine and Director of Cardiology at the University of Rouen's Charles Nicolle Hospital. Alain Cribier is best known for performing the world's ...
in Hopital Charles Nicolle, at the University of Rouen The University of Rouen Normandy (''Université de Rouen Normandie'') is a French university, in the Academy of Rouen.
History and demographics
Located not in Rouen, but in the suburb of Mont-Saint-Aignan (a "township" in the Normandy region), th ...
, France. Technology experts Stan Rowe and Stan Rabinowitz partnered with physicians Alain Cribier and Martin Leon of NewYork–Presbyterian The NewYork-Presbyterian Hospital is a nonprofit academic medical center in New York City affiliated with two Ivy League medical schools, Cornell University and Columbia University. The hospital comprises seven distinct campuses located in the New Y ...
Hospital and others to create the company Percutaneous Valve Technologies (PVT) in 2002. The company was purchased by Edwards Lifesciences
Edwards Lifesciences is an American medical technology company headquartered in Irvine, California, specializing in artificial heart valves and hemodynamic monitoring. It developed the SAPIEN transcatheter aortic heart valve made of cow tissue wi ...
in 2004; its valve became the Sapien valve. It was the first aortic valve device to receive FDA approval, in November 2011 for use in inoperable patients and in October 2012 for use in patients at high surgical risk. The device is effective in improving functioning in patients with severe aortic stenosis. It is now approved in more than 50 countries.
Internationally famous pop singer Mick Jagger
Sir Michael Philip Jagger (born 26 July 1943) is an English singer and songwriter who has achieved international fame as the lead vocalist and one of the founder members of the rock band the Rolling Stones. His ongoing songwriting partnershi ...
had the procedure in March 2019 at NewYork–Presbyterian, which was said to have raised public awareness.
References
Further reading
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Cardiac procedures