Bentall Procedure: Comprehensive Clinical Overview
What is the Bentall Procedure?
The Bentall procedure is a composite aortic root replacement that simultaneously replaces the ascending aorta and aortic valve with a valved conduit, followed by reimplantation of the coronary arteries into the graft using a "button technique." 1 This operation addresses combined pathology affecting both the aortic root and valve in a single surgical intervention. 1
Primary Indications for Surgery
Size-Based Thresholds
For Marfan syndrome patients, surgery is recommended when the aortic root reaches ≥50 mm diameter. 2, 3 However, earlier intervention at ≥45 mm should be considered when additional risk factors are present, including: 2
- Rapid aortic growth (≥0.3 cm/year or ≥3 mm/year)
- Family history of aortic dissection
- Desire for pregnancy
- Severe aortic regurgitation
- Patient preference
For tricuspid aortic valve patients without genetic syndromes, surgery is indicated at ≥55 mm. 2, 3
For bicuspid aortic valve patients, the threshold is ≥50 mm. 3
Alternative Sizing Criteria
When the maximal aortic cross-sectional area (cm²) divided by patient height (m) reaches ≥10 cm²/m, prophylactic root replacement is reasonable. 2 This indexed approach accounts for body size variations and has demonstrated favorable outcomes. 2
Emergency Indications
Any symptomatic patient with chest pain, back pain, dyspnea, or other symptoms attributable to the aneurysm requires prompt surgical intervention regardless of size. 4 Acute type A aortic dissection involving the aortic root with valve dysfunction mandates emergency Bentall procedure. 1
Pre-Operative Evaluation
Essential Imaging
Obtain cardiovascular computed tomography (CCT) or cardiovascular magnetic resonance (CMR) to define precise anatomy, measure exact diameters, assess valve morphology, and evaluate the extent of aortic involvement. 2, 4 Transthoracic echocardiography (TTE) alone is insufficient for surgical planning. 4
Transoesophageal echocardiography (TOE) should be performed immediately before surgery to assess valve function and confirm the surgical plan. 2
Risk Assessment
Evaluate for connective tissue disorders (Marfan, Loeys-Dietz), bicuspid aortic valve, family history of aortic disease, and prior cardiac surgeries. 5 These factors influence surgical approach and timing. 2
Assess bleeding risk, ability to maintain anticoagulation, and patient age to guide valve selection (mechanical vs. bioprosthetic). 1
Operative Steps
Surgical Access
Perform median sternotomy to expose the ascending aorta and aortic root. 2, 1 Make the pericardial incision in the midline inferiorly to avoid the friable dissected ascending aorta in acute dissection cases. 2, 1
Establish extracorporeal circulation by cannulating a femoral artery and the right atrium. 2, 1
Core Surgical Technique
1. Aortic Root Excision: Remove the diseased ascending aorta and aortic valve completely. 1
2. Annular Suture Placement: Place transmural mattress sutures through the aortic annulus and pass them through the cardiac end of the prosthetic composite graft. 2, 1 Secure the graft to the left ventricular outflow tract proximally. 1
3. Coronary Button Technique: Excise the coronary ostia as circular "buttons" of aortic wall. 1, 6 This full-thickness button technique is superior to the original Bentall method and reduces pseudoaneurysm formation. 3, 7 Create corresponding openings in the sides of the composite conduit at appropriate locations. 1 Anastomose each coronary button directly to its graft opening, ensuring tension-free connections. 1
4. Distal Anastomosis: Attach the distal end of the tube graft to uninvolved ascending aorta. 1 In most cases, extend the replacement to the junction of the ascending aorta and arch, or beyond, to ensure healthy tissue coverage. 1 If aneurysmal disease extends into the proximal aortic arch (>50 mm), perform concomitant hemi-arch replacement. 2
Valve Selection
Mechanical prosthetic valves provide long-term durability but require lifelong anticoagulation with vitamin K antagonists. 2, 1 These are preferred for younger patients who can maintain anticoagulation. 1
Bioprosthetic (tissue) valves avoid lifelong anticoagulation but have limited durability, especially in younger patients. 1 Consider bioprosthetic valves for elderly patients (typically >65 years), those with contraindications to anticoagulation, or those unable to maintain anticoagulation therapy. 1
Critical Technical Pitfalls and Prevention
Coronary ostial tension: When coronary ostia lie close to the aortic annulus and a stiffened aortic wall creates tension, they must be excised as buttons before anastomosis to prevent anastomotic failure. 2, 1
Coronary obstruction or kinking: Meticulous positioning of the coronary buttons and tension-free anastomosis are essential to prevent postoperative coronary obstruction. 1 If a small torn ostium has irreparable damage, bypass grafting using saphenous vein segments is required. 2
Inadequate distal extent: In acute dissections, ensure the distal anastomosis reaches healthy, non-dissected aorta to prevent recurrent dissection. 1 Use teflon felt or tissue adhesive (gelatin resorcinol formaldehyde glue) to create a firm, leak-proof seal on acutely dissected tissue. 2
Bleeding complications: The dissected aortic wall is friable and prone to bleeding. 2 Sandwich dissected layers between teflon felt strips placed inside and outside the aortic wall to achieve hemostasis. 2
Postoperative Management
Anticoagulation
Lifelong vitamin K antagonist (VKA) therapy is mandatory for all patients with mechanical valve prostheses. 2, 3
For bioprosthetic valves, single antiplatelet therapy with low-dose aspirin (75-100 mg/day) or oral anticoagulation using a VKA should be considered for the first 3 months after surgery. 2
Surveillance Imaging
Perform TTE before discharge to assess for immediate cardiac complications (pericardial effusion, valve function). 2
At 1 month postoperatively, obtain TTE to assess valve function and gradients, plus CCT or CMR to evaluate the aortic root and proximal ascending aorta. 2, 3
For mechanical prostheses or native valves (valve-sparing procedures), perform TTE annually or as clinically indicated if new cardiac symptoms develop. 2
For bioprosthetic valves, perform TTE annually to monitor for structural valve deterioration. 2, 3
If the aorta is not fully repaired (residual aneurysmal disease elsewhere), obtain CCT or CMR at 1 year, then every 2 years, then every 5 years if stable. 2, 3 If the entire aorta was repaired, surveillance imaging at 2 years and then every 5 years is reasonable. 2
Potential Complications
Early Complications
Operative mortality at experienced centers is <1% for elective Bentall procedures. 2 However, emergency surgery for acute dissection or rupture carries significantly higher mortality (approximately 10-15%). 7, 8
Bleeding requiring reoperation occurs in 2-5% of cases, particularly in acute dissection. 7
Stroke and neurological complications occur in 1-3% of elective cases. 7
Late Complications
Thromboembolic complications (stroke, systemic embolism) occur at a rate of 1-2% per patient-year with mechanical valves despite anticoagulation. 9
Bleeding complications from anticoagulation occur at 1-2% per patient-year. 9
Prosthetic valve endocarditis occurs at 0.5-1% per patient-year. 7
Reoperation is required in approximately 10-15% of patients at 5 years, primarily for bleeding complications, pseudoaneurysm formation, or valve dysfunction. 7
Structural valve deterioration of bioprosthetic valves necessitates reoperation in 20-30% of patients by 10 years, with higher rates in younger patients. 5
Alternative Surgical Options
Valve-Sparing Root Replacement (VSRR)
Valve-sparing aortic root replacement using the David procedure (reimplantation) or Yacoub technique (remodeling) is recommended in experienced centers when the aortic valve cusps are pliable and durable results are expected. 2 This approach avoids lifelong anticoagulation and its associated risks. 2, 1
The advantage of VSRR is that patients can potentially avoid the lifelong risks and complications associated with prosthetic valves. 2 However, durability of the spared native valve is a concern; approximately 7% develop at least moderate aortic regurgitation at 1 year, and 5-10% require reoperation for valve failure within 5-10 years. 2, 9
VSRR requires longer cardiopulmonary bypass and cross-clamp times compared to Bentall procedures. 5 These procedures are more complex and time-consuming, requiring significant surgical expertise. 2, 1
In emergency settings of acute type A dissection, the Bentall procedure is preferable because it is less complex and faster than valve-sparing operations. 1 Valve-sparing procedures should only be performed in acute dissection by surgeons with broad experience in elective cases. 2
Supracoronary Tubular Graft
For isolated dilatation of the ascending tubular (supra-coronary) aorta without root involvement, a supra-commissural tubular graft is inserted with the distal anastomosis just before the aortic arch. 2, 4 This preserves the native aortic valve and root when they are not diseased. 2
Homograft or Xenograft Root Replacement
Implantation of allografts and xenografts should be restricted to elderly patients or special indications, since late postoperative degeneration may require reoperation on the aortic root. 2 These are not routinely recommended for younger patients. 8
Surgical Risk and Outcomes
When performed by experienced surgeons in multidisciplinary aortic teams, aortic root replacement is associated with very low surgical risk (<1% mortality). 2 Experienced cardiac surgery centers report <1% mortality with elective surgery. 2
In patients with Marfan syndrome, elective aortic root and ascending aortic replacement before aortic dissection improves survival dramatically compared to historical controls. 2 A landmark 1995 report documented marked improvement in lifespan among Marfan patients treated with elective aortic repair. 2
The modified Bentall procedure with button technique is one of the two most commonly performed aortic root replacements in the United States for individuals with Marfan syndrome. 1, 3 The button technique has become the routine procedure of choice, with the classic Bentall and Cabrol variation reserved for special circumstances. 7
Five-year actuarial survival for all Bentall patients is approximately 79-85%, with freedom from reoperation of 87% at 5 years. 7 Event-free survival (freedom from death, reoperation, or valve-related complications) is 67% at 5 years. 7
Comparative studies show that VSRR patients have higher combined freedom from death and reoperation than Bentall patients, but this reflects patient selection bias, as Bentall patients tend to have more severe or emergent cases. 5 In experienced centers, VSRR carries equivalent morbidity and mortality with improved survival in appropriately selected patients. 5, 9