Grafts/Materials
Grafts and materials questions test conduit choice, prosthetic behavior and infection risk. The exam expects material-specific complications and long-term trade-offs.
Core rules
- Left internal thoracic artery to LAD is the standard conduit for CABG because of patency and survival benefit; radial artery and saphenous vein have different patency profiles.
- Prosthetic valves require anticoagulation for mechanical valves; bioprosthetic valves have lower anticoagulation burden but structural degeneration over time.
- Patches and conduits differ in infection resistance, handling and durability; Dacron and PTFE are not interchangeable in every site.
- Suture material is selected by tissue, tension and expected healing.
Worked example
A young patient needs aortic valve replacement and cannot reliably take warfarin. The reasoning should weigh mechanical valve durability against anticoagulation risk. A bioprosthesis may be chosen despite younger age if anticoagulation is unsafe, but the trade-off is reintervention risk.
Traps
Do not use prosthetic material in an infected field without debridement; do not assume all bioprostheses avoid anticoagulation entirely; do not ignore conduit quality; do not choose a graft solely by surgeon preference.