What are the key findings that need to be checked and reported on a CT (Computed Tomography) scan for a patient who has undergone Minimally Invasive Cardiac Surgery (MICS) for Mitral Valve Repair (MVR)?

CT Imaging Requirements for MICS MVR

For patients undergoing minimally invasive cardiac surgery (MICS) for mitral valve repair (MVR), CT angiography of the chest, abdomen, and pelvis with contrast is essential and should systematically evaluate the aorta, peripheral vasculature, mitral valve annulus, chest wall anatomy, and great vessel variants to minimize stroke risk and optimize surgical planning. 1

Critical Vascular Assessment

Aortic Evaluation

• Measure ascending aortic diameter - must be <4 cm if endoaortic balloon occlusion is planned, as complete occlusion becomes inconsistent in larger aortas 1
• Assess atheroma burden including degree, location, and plaque characteristics (hard versus soft plaque) throughout the ascending aorta 1
• Document any aortic pathology that would preclude safe aortic cross-clamping or endoaortic balloon placement 1
• Systematic preoperative CT screening reduces postoperative stroke risk from 2.2% to 1.5% (p=0.03) by identifying high-risk aortic disease 2

Peripheral Arterial Assessment

• Evaluate iliac arteries for aneurysm, tortuosity, plaque burden, and any localized dissection or pseudoaneurysm from previous catheterization sites 1
• Measure common femoral artery diameter and identify the bifurcation point to determine optimal cannulation site 1
• Assess superficial femoral artery patency and caliber for peripheral cannulation planning 1
• Document any significant peripheral vascular disease that would prevent safe retrograde arterial perfusion 1

Venous Anatomy

• Rule out venous anomalies including persistent left superior vena cava or aberrant venous drainage 1
• Identify presence of IVC filters that would complicate venous cannulation 1

Cardiac and Valvular Assessment

Mitral Valve Annulus

• Evaluate degree and location of mitral annular calcification - significant calcification is a relative contraindication for MICS MVR in inexperienced surgeons due to increased risk of atrioventricular disruption 1
• Assess annular geometry to predict repair complexity 3, 4

Great Vessel Variants

• Rule out aberrant anatomy including patent ductus arteriosus, persistent left superior vena cava, and aberrant right subclavian artery 1
• These variants may complicate endoaortic balloon monitoring or central venous access 1

Anatomic Planning for Surgical Access

Chest Wall and Thoracic Anatomy

• Identify optimal working port location relative to the pulmonary hilum - typically the fourth intercostal space, but CT may guide placement above or below to align with the hilum 1
• Assess chest wall deformities including kyphoscoliosis and pectus excavatum that could complicate the surgical approach 1
• Evaluate rib spacing and chest wall thickness to ensure adequate access 1
• Document diaphragm position and any anatomic abnormalities 1

Cardiac Position

• Assess cardiac position within the thorax to predict exposure challenges 5, 4
• Evaluate right ventricular size as massive RV enlargement may compromise surgical access 1

Additional Risk Stratification

Stroke Risk Assessment

• Quantify total atherosclerotic burden in the aorta and great vessels - significant atheroma increases stroke risk and may make MICS MVR less ideal 1
• CT screening reduces need for new dialysis from 2.3% to 0.8% (p=0.02) by identifying high-risk vascular anatomy 2

Coronary Artery Evaluation

• Assess coronary artery anatomy if coronary CT angiography is performed, particularly left main ostium location relative to planned aortic occlusion 1, 5

Common Pitfalls to Avoid

• Failure to obtain contrast-enhanced CT - non-contrast CT provides limited vascular detail and may miss critical atherosclerotic disease 1
• Inadequate imaging of peripheral vessels - imaging must extend through the femoral bifurcation to plan cannulation sites 1
• Overlooking great vessel variants - aberrant anatomy discovered intraoperatively can complicate monitoring and perfusion 1
• Underestimating mitral annular calcification - severe calcification significantly increases technical difficulty and complication risk 1

Integration with Echocardiography

While CT provides superior anatomic and vascular detail, echocardiography remains essential for assessing aortic atheroma in conjunction with chest CT, as some soft plaques may be better visualized with ultrasound 1. TEE is mandatory intraoperatively for real-time guidance and immediate assessment of repair adequacy 5, 6.