What are the indications for Bentall procedure in a patient with Marfan syndrome?

Indications for Bentall Surgery in Marfan Syndrome

In patients with Marfan syndrome, the Bentall procedure (composite valve-graft conduit with coronary reimplantation) is indicated when aortic root diameter reaches ≥5.0 cm, or earlier at ≥4.5 cm when additional risk factors are present, particularly when significant aortic regurgitation coexists or valve-sparing surgery is not feasible. 1

Primary Size-Based Indications

The fundamental threshold for aortic root surgery in Marfan syndrome is an external aortic diameter of ≥5.0 cm, which is lower than the 5.5 cm threshold used for non-syndromic patients due to the increased propensity for dissection at smaller diameters. 1

Body Size Indexing

• When the maximal aortic root cross-sectional area (cm²) divided by patient height (m) reaches ≥10 cm²/m, prophylactic root replacement is reasonable regardless of absolute diameter. 1
• This indexed approach is particularly important for patients with small or large body habitus where absolute measurements may be misleading. 1

Indications for Earlier Surgery (<5.0 cm)

Surgery should be performed at diameters <5.0 cm when any of the following high-risk features are present:

• Rapid aortic growth ≥0.3-0.5 cm/year on serial imaging with side-by-side comparison 1, 2
• Family history of aortic dissection, especially if dissection occurred at diameters <5.0 cm 1, 2
• Severe (3-4+) aortic regurgitation requiring intervention 1, 2
• Desire for pregnancy in women, as pregnancy significantly increases dissection risk when diameter exceeds 4.0 cm 1, 2
• Aortic diameter >4.0 cm in pregnant patients warrants urgent consideration 1

Bentall vs. Valve-Sparing Procedures: Decision Algorithm

The choice between Bentall procedure and valve-sparing root replacement (VSRR, David procedure) depends on specific anatomical and clinical factors:

Bentall Procedure is Preferred When:

• Significant aortic valve pathology exists with moderate-to-severe (3-4+) aortic regurgitation that cannot be repaired 3, 4, 5
• Acute aortic dissection is present, as these patients typically have more valve damage 3, 5
• Emergency or urgent surgery is required 3, 5
• Aortic valve cusps are structurally abnormal and unsuitable for preservation 1

Valve-Sparing (David) Procedure Should Be Considered When:

• Aortic valve cusps are structurally normal with minimal or no regurgitation 1
• Surgery is elective and performed by experienced surgeons in a Multidisciplinary Aortic Team 1
• Patient desires to avoid lifelong anticoagulation, particularly younger patients or women of childbearing age 3, 5
• Aortic diameter is approaching threshold (4.5-5.0 cm) in low-risk surgical candidates 1

Clinical Outcomes and Considerations

Bentall Procedure Characteristics:

• Operative mortality <1.1% in elective cases at experienced centers 6
• Requires lifelong anticoagulation with mechanical valve, carrying 9% thromboembolic event rate at 8 years 3
• Lower reoperation rates (2% at 8 years) compared to valve-sparing 3
• Shorter operative times (cross-clamp 77±17 minutes) 4

Valve-Sparing Procedure Characteristics:

• Avoids anticoagulation but carries 6-7% risk of developing moderate AR requiring reoperation 1, 3
• Freedom from aortic valve replacement 90% at 8 years 3
• Significantly fewer thromboembolic/hemorrhagic events (hazard ratio 0.16) compared to Bentall 5
• Longer operative times (cross-clamp 116±30 minutes) but similar survival 4, 5

Special Populations

Pregnant Patients:

• Aortic diameter >4.0 cm before conception is an indication for prophylactic surgery prior to pregnancy 1, 2
• Frequent cardiovascular monitoring throughout pregnancy and puerperium is mandatory for all Marfan women 1
• Cesarean section with concomitant aortic repair is preferred if dissection occurs during pregnancy 1

Patients with Prior Cardiac Surgery:

• The Bentall procedure may be technically simpler in reoperative cases, though both procedures can be performed safely. 7

Critical Pitfalls to Avoid

• Do not delay surgery until 5.5 cm as used in non-Marfan patients; dissection risk increases substantially above 5.0 cm 1, 2
• Do not use internal diameter measurements alone; guidelines reference external diameters, and internal measurements underestimate true size 1
• Do not assume medical therapy eliminates surgical need; beta-blockers and ARBs slow but do not prevent aortic growth 1
• Do not perform valve-sparing in emergency dissection cases; the Bentall procedure is more appropriate for acute presentations 3, 5
• Do not forget lifelong surveillance of remaining aortic segments post-operatively, as arch and descending aorta remain at risk 1