Coronary Artery Bypass Grafting (CABG) Flashcards

The internal mammary artery (IMA) is preferred for coronary bypass grafting because:

Answer: It has superior long-term patency compared to saphenous vein grafts

The left internal mammary artery has a 10-year patency rate exceeding 90%, far superior to saphenous vein grafts (50–60%), making it the gold-standard conduit.

The most common coronary artery target for the left internal mammary artery (LIMA) graft in CABG is:

Answer: Left anterior descending (LAD) artery

LIMA-to-LAD grafting is the cornerstone of CABG because the LAD supplies the largest territory and the LIMA-LAD anastomosis has the best long-term outcomes.

Off-pump CABG (OPCAB) differs from conventional CABG primarily in that:

Answer: The procedure is performed on a beating heart without cardiopulmonary bypass

OPCAB avoids CPB by using mechanical stabilizers and heart positioners to expose coronary targets while the heart continues beating.

The saphenous vein graft failure rate at 10 years is approximately:

Answer: 40–50%

Saphenous vein graft attrition is significant, with approximately 40–50% of vein grafts occluded by 10 years due to intimal hyperplasia and atherosclerosis.

Competitive flow in a coronary bypass graft occurs when:

Answer: A native coronary with moderate stenosis provides sufficient native flow to outcompete the graft

Competitive flow occurs when the native coronary is not critically stenosed, allowing antegrade native flow to compete with graft flow and potentially causing graft failure.

Which intraoperative finding most commonly prompts conversion from off-pump to on-pump CABG?

Answer: Hemodynamic instability during cardiac displacement

Hemodynamic instability when the heart is displaced to expose posterior targets is the most common reason for urgent conversion to CPB during OPCAB.