OR / Prep · Cardiac Surgery · open
You’re scrubbing into
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.
Read the imaging first
Practice before you scrub
Read the coronary angiogram
A 68-year-old with diabetes and exertional angina despite medical therapy. Coronary angiography is performed. (Fictional educational case.)
- Proximal LAD and left main disease pull hardest toward CABG: the muscle at stake is the argument.
- A lesion is only bypassable if the vessel beyond it is worth sewing to: the surgeon reads targets, not just narrowings.
The anatomy the operation is built on
The operation in 4 steps
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.
02Cannulation, bypass, arrest
Heparin, aortic and venous cannulation, onto the pump; the aorta is cross-clamped and cold cardioplegia arrests the heart.
03The anastomoses
Each target artery is opened beyond its disease and conduit sewn on with fine continuous suture; proximal vein ends join the aorta.
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.
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.
Watch it done
Cardiopulmonary bypass: the role of the circuit
Why the operation needs a machine at all: a still, bloodless heart with the body still perfused.
Source: CTSNet · Watch on YouTubeCardiopulmonary bypass: the circuit
The path blood takes from the venous cannula through the reservoir, oxygenator and pump back into the aorta.
Source: CTSNet · Watch on YouTubeCardiopulmonary bypass: circuit components
Each part of the circuit named and explained: cannulae, reservoir, pump heads, oxygenator, filters and suckers.
Source: CTSNet · Watch on YouTubeCardiopulmonary bypass: pathophysiology
What non-pulsatile flow, haemodilution, hypothermia and the foreign circuit do to the body, and why the ICU course follows.
Source: CTSNet · Watch on YouTubeCardiopulmonary bypass: conduct and weaning
Going on, running the pump, and the choreography of coming off: rewarming, rhythm, filling and the cannulae out.
Source: CTSNet · Watch on YouTubeCardiopulmonary bypass: emergency scenarios
What goes wrong on the pump and what the team does in the first minute: air, dissection at the cannula, pump failure, oxygenator failure.
Source: CTSNet · Watch on YouTubeCoronary artery bypass surgery
Sternotomy, conduit, bypass and the grafts, in the words of the centre that does the most of them.
Source: Cleveland Clinic · Watch on YouTube
Conceptual teaching for learners preparing to observe and assist under supervision, not operative instructions. Five minutes from now you should know why this operation exists, what its shape is, and which structures it is designed not to injure.