Valve-sparing aortic root replacement (also known as the David procedure) is a cardiac surgery procedure which is used to treat

Aortic aneurysm An aortic aneurysm is an enlargement (dilatation) of the aorta to greater than 1.5 times normal size. Typically, there are no symptoms except when the aneurysm dissects or ruptures, which causes sudden, severe pain in the abdomen and lower back ...

s and to prevent

Aortic dissection Aortic dissection (AD) occurs when an injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart. In most cases, this is associated with a sudden onset of agonizing ches ...

. It involves replacement of the aortic root without 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. ...

. Two similar procedures were developed, one by Sir Magdi Yacoub, and another by Tirone David.

Techniques

The valve-sparing aortic root replacement allows for direct narrowing of enlarged aortas, which change the fluid dynamics of outbound blood from the heart, while preserving the natural tissues of the aortic valve, which means the patient does not have to rely on

anticoagulant An anticoagulant, commonly known as a blood thinner, is a chemical substance that prevents or reduces the coagulation of blood, prolonging the clotting time. Some occur naturally in blood-eating animals, such as leeches and mosquitoes, which ...

s. Common features of both techniques of the replacement process are the clamping of the aorta and the use of a length of

Dacron Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods ...

tube (also known as an "aortic graft"), typically 5 cm, to constrict the aortic root to the normal diameter, while the patient is cooled to 20°C and placed on life support. The procedure typically takes 4 to 6 hours in healthy patients.

Re-modeling technique

Established by Sir Magdi Yacoub in the mid-1990s, the process involves cutting the aorta superior of (slightly downstream of) the

and attaching the tube, one end of which has been shaped into a three-lobed wavy ring, directly to the

commissure A commissure () is the location at which two objects wikt:abut#Verb, abut or are joined. The term is used especially in the fields of anatomy and biology. * The most common usage of the term refers to the brain's commissures, of which there are at ...

s connecting the aortic valve to the aortic wall. In other words, the "sinotubular junction" holding the aortic valve in place is reformed with the tube flush with the outermost valve tissue, and extending between the valve's cusps.

Re-implantation technique

Established by Tirone E. David and Christopher Feindel at the

Toronto General Hospital The Toronto General Hospital (TGH) is a major teaching hospital in Toronto, Ontario, Canada and the flagship campus of University Health Network (UHN). It is located in the Discovery District of Downtown Toronto along University Avenue (Toronto), ...

in 2007, this technique differs in the shape of the Dacron tube's end, which here is a ring with a flat edge, and its location, with the sinotubular junction "inserted" into the tube. In other words, the tube acts like a "corset" on the outside of the wall surrounding the aortic valve, though the tube's attachment points are the same as in the Yacoub method.

Results

A 2023 literature review of David method patient outcomes after 2010 found that the chances of complications such as endocarditis and stroke, were reduced to 0.3%, while survival rates were 99% within a year and 89% within a decade afterward. The most common reason for follow-up (typically needed in 5 years) was minor chest bleeding, reported by 5.4% of patients.

References

External links