Medical Archive

Cardiac assessment

Extracorporeal perfusion

Coronary artery disease

Coronary artery bypass grafting

Indications

Percutaneous Coronary Intervention vs. Coronary Artery Bypass Grafting

Summary

Operative Techniques and Results

Bypass Conduit Selection

Conventional Coronary Artery Bypass Grafting

• Complications
  • Atrial fibrillation
    • Commonly (up to 15%-40%) occurs within a few days after CABG and is usually self-limited, with resolution in <24 hours.
  • Soft tissue dehiscence
    • Occurs when only the superficial tissues (eg, skin, muscle) separate. There are no signs of sternal instability or systemic illness
    • Local wound care or debridement followed by primary closure is indicated.
  • Sternal dehiscence
    • Surgical emergency d/t loosening or fracture of the suture wire.
    • Risk factors
      • Obesity, macromastia, sequelae of COPD increase tensile forces on the wound closure.
      • Sternal ischemia (internal thoracic artery harvesting, DM, smoking)
    • Diagnosis
      • Radiograph (eg, displaced sternal wires)
      • Clinical (eg, palpable rocking or clicking of the sternum, Mild pain or sensation of chest wall instability and “clicking” with chest movement)
    • Treatment
      • Urgent surgical exploration, debridement
      • Sternal fixation – rewiring or sternal plate placement
  • Mediastinitis
    • Deep tissue infection, a high-mortality complication of dehiscence.
    • D/t either contiguous spread of superficial infection or intraoperative deep tissue contamination.
    • Diagnosis
      • Systemic symptoms (eg, fever, tachycardia), chest pain, chest wall edema/crepitus, and purulent wound discharge.
      • Chest and sternal imaging
        • Mediastinal fluid collections or pneumomediastinum on CT
        • Any patient with significant sternal wound drainage should be evaluated.
    • Treatment
      • Emergency surgical debridement, tissue culture, and empiric IV antibiotics.

Conventional CABG Results

Off-pump Coronary Artery Bypass

OPCAB results

Minimally Invasive Direct Coronary Artery Bypass

Total Endoscopic Coronary Artery Bypass

Hybrid Coronary Revascularization

Transmyocardial Laser Revascularization

New Developments

Regenerative Medicine and Tissue Engineering

Valvular heart disease

General principles

Long term anticoagulation with warfarin.

Surgical options

Mechanical valves
Tissue valves
Homografts
Autografts
Valve repair

Mitral valve disease

Aortic valve disease

Tricuspid valve disease

Surgical therapy for the failing heart

Surgery for arrhythmias

Surgery for pericardial disease

Cardiac neoplasms

# Prosthetic valve

Prosthetic valve thrombosis (PVT)

Prevention

• Aspirin
  • 75-100 mg/day
• Warfarin
  • Mitral valve: with target INR 2.5-3.5
  • Aortic valve: with target INR 2.0-3.0

Pathophysiology

Mitral valve risk > aortic valve risk

Due to relatively low flow velocity between the left atrium and left ventricle, PVT affects mechanical mitral valves twice as often as mechanical aortic valves.

Inadequate anticoagulation is the strongest risk factor.

Clinical features

Obstructive thrombus mimics valvular stenosis.
Heart failure, cardiogenic shock.
Systemic thromboembolic events (eg, stroke)

Diagnosis and treatment

Echocardiogram visualizes thrombus
Anticoagulation (eg, heparin)
Fibrinolytic therapy (typically avoided if possible)
Immediate surgery for severe heart failure or large thrombus