Coronary artery bypass grafting

Why are we operating?

New plumbing around blocked coronaries: conduit from the chest wall and leg, grafted onto the arteries beyond their disease, classically on a heart stopped and lent to a machine.

Indication: Left main or three-vessel coronary disease, and diabetics with multivessel disease, where surgery outlives stenting.

The operation in 4 steps

1. 01Sternotomy and conduit harvest

   Median sternotomy; the left internal mammary artery is taken down from the chest wall while the saphenous vein is harvested from the leg.

   Why: The LIMA is the single best conduit in cardiac surgery: grafted to the LAD it stays open for decades, and that one graft carries most of the operation's survival benefit.

2. 02Cannulation, bypass, arrest

   Heparin, aortic and venous cannulation, onto the pump; the aorta is cross-clamped and cold cardioplegia arrests the heart.

   Why: A still, bloodless field is what lets millimetre anastomoses succeed. Cardioplegia stops the heart in diastole and drops its oxygen demand so far that the clamped hour is survivable.

3. 03The anastomoses

   Each target artery is opened beyond its disease and conduit sewn on with fine continuous suture; proximal vein ends join the aorta.

   Why: The graft lands where the artery is soft and runs downstream of every stenosis; the operation's value is decided by what flows through these joins tomorrow and in ten years.

4. 04Weaning and closure

   The clamp comes off, the heart is re-perfused and paced back to work, bypass is weaned, protamine reverses heparin, drains and sternal wires close.

   Why: Coming off pump is a negotiation, not a switch: rhythm, filling and contractility are rebuilt in order, and the bleeding conversation with protamine ends the case.

Danger zones

• Left main coronary artery

  Two territories hang from one vessel; its disease changes the whole operative plan.

• AV nodal artery

  Injury or occlusion at the crux trades a rhythm for an infarct.

• Coronary sinus

  Thin-walled and posterior, easily torn by retraction during mitral exposure.

Anatomy you need

The coronaries on the surface they actually run on: LAD down the front, circumflex round the left, RCA in the right groove.

What can go wrong

• Postoperative bleeding

  Tachycardia first, hypotension late; falling urine output; a distending abdomen or rising drain output.

• Surgical-site infection

  Wound erythema, warmth, discharge, and pain out of proportion, typically from postoperative day 4–7.

• Atelectasis & pulmonary complications

  Low-grade fever and mild desaturation in the first 48 hours, especially after upper-abdominal incisions.

• Venous thromboembolism

  Unilateral leg swelling, or sudden dyspnoea, pleuritic pain, tachycardia, sometimes the only sign is unexplained hypoxia.