Valve-sparing aortic root replacement

Valve-sparing aortic root replacement (also known as the David procedure) is a cardiac surgery procedure which is used to treat Aortic aneurysms and to prevent Aortic dissection.^[1] It involves replacement of the aortic root without replacement of the aortic valve. Two similar procedures were developed, one by Sir Magdi Yacoub,^[2] and another by Tirone David.^[3][4]

Valve-sparing aortic root replacement
Other names	David procedure
Specialty	Cardiology, cardiothoracic surgery

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 anticoagulants. Common features of both techniques of the replacement process are the clamping of the aorta and the use of a length of Dacron 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.^[1][5]

Re-modeling technique

Established by Sir Magdi Yacoub in the mid-1990s, the process involves cutting the aorta superior of (slightly downstream of) the aortic valve and attaching the tube, one end of which has been shaped into a three-lobed wavy ring, directly to the commissures 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.^[6][7]

Re-implantation technique

Established by Tirone E. David and Christopher Feindel at the Toronto General Hospital in 2007,^[8] 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.^[9][10][11]

Comparison with alternative procedures

Valve-sparing aortic root replacement (David procedure) is one of several surgical options for treating aortic root aneurysms and preventing aortic dissection. The choice of procedure depends on the patient's anatomy, the presence of valve disease, and surgeon expertise.

David procedure vs. PEARS procedure

The Personalized External Aortic Root Support (PEARS procedure) is a less invasive alternative to the David procedure:

• Approach: PEARS uses an external, custom-made mesh (ExoVasc®) to reinforce the aortic root without removing aneurysmal tissue, while the David procedure involves internal replacement of the aortic root with a synthetic graft.^[12][13]
• Invasiveness: PEARS is typically performed on a beating heart without cardiopulmonary bypass, resulting in a shorter procedure time (~2 hours) compared to the David procedure (4–6 hours).^[14][15]
• Indications: PEARS is often used for early-stage aortic root dilation, while the David procedure is reserved for more advanced aneurysms or when the aorta reaches a critical size for replacement.^[13][14]
• Tissue Preservation: Both procedures preserve the native aortic valve, but PEARS retains all native aortic tissue, whereas the David procedure excises the aneurysmal root.^[12][16]
• Recovery: PEARS generally results in faster recovery and shorter hospital stays, but long-term outcomes are still under investigation, whereas the David procedure has well-established long-term results.^[15][14]
• Limitations: PEARS is not suitable for very large aneurysms (typically >50 mm), and patients may require further surgery if the aorta continues to dilate.^[12]

David procedure vs. Bentall procedure

The Bentall procedure involves replacement of the aortic root and valve with a composite graft (mechanical or bioprosthetic valve sewn into a Dacron tube).^[17]

• Valve Preservation: Unlike the David procedure, the Bentall procedure replaces the aortic valve, requiring lifelong anticoagulation if a mechanical valve is used.
• Indications: The Bentall procedure is typically chosen when the aortic valve is diseased or cannot be preserved, or in cases of acute aortic dissection.^[17]
• Outcomes: Both procedures have excellent long-term survival, but the David procedure avoids the risks and lifestyle restrictions associated with mechanical valves.^[18]

David procedure vs. Yacoub procedure

The Yacoub procedure (remodeling technique) is another valve-sparing option, differing from the David procedure (reimplantation technique) in the method of graft attachment:

• Technique: The Yacoub procedure reshapes the sinotubular junction with a Dacron graft shaped into a three-lobed ring, while the David procedure reimplants the valve inside a straight Dacron tube.^[19]
• Valve Dynamics: The Yacoub procedure may better preserve native valve dynamics, but the David procedure is associated with lower rates of late valve dysfunction.^[18][20]

David procedure vs. Ross procedure

The Ross procedure involves replacing the aortic valve with the patient's own pulmonary valve (autograft) and replacing the pulmonary valve with a homograft.

• Indications: The Ross procedure is often used in children or young adults, as the autograft can grow with the patient and does not require anticoagulation.
• Complexity: The Ross procedure is more complex and is typically reserved for specific cases, such as young patients with aortic valve disease and a healthy pulmonary valve.^[21]

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.^[22]

See also

• Aortic aneurysm
• Aortic dissection
• Marfan syndrome
• PEARS procedure
• Bentall procedure
• Yacoub procedure
• Ross procedure