CVP CVP Cannulation Techniques and Circulatory Support 1 — Questions and Answers
Question 1: What is the most common site for arterial cannulation in standard cardiopulmonary bypass?
- Femoral artery
- Axillary artery
- Ascending aorta (Correct answer)
- Carotid artery
Correct answer: Ascending aorta
The ascending aorta is the preferred arterial cannulation site for standard CPB because it provides direct, high-flow access to the systemic arterial circulation.
Question 2: When is femoral artery cannulation preferred over ascending aortic cannulation?
- In all pediatric patients
- In cases of aortic dissection, severe aortic calcification, or redo sternotomy (Correct answer)
- For routine isolated CABG procedures
- When the patient has peripheral vascular disease
Correct answer: In cases of aortic dissection, severe aortic calcification, or redo sternotomy
Femoral cannulation provides alternative arterial inflow when the ascending aorta is unsafe due to dissection, heavy calcification, or inaccessibility during redo sternotomy.
Question 3: What is the primary risk of cannulating or clamping a severely calcified ('porcelain') aorta?
- Ventricular fibrillation
- Systemic embolization of atherosclerotic debris causing stroke or organ ischemia (Correct answer)
- Acute cardiac arrest
- Pulmonary edema
Correct answer: Systemic embolization of atherosclerotic debris causing stroke or organ ischemia
Manipulating a heavily calcified aorta can dislodge atheromatous plaques that embolize to the brain, kidneys, or other end organs, causing stroke or ischemia.
Question 4: Which venous cannulation technique uses a single cannula positioned in the right atrium with drainage holes extending into the inferior vena cava?
- Bicaval cannulation
- Single two-stage venous cannula (Correct answer)
- Femoral venous cannula
- Superior vena cava cannula
Correct answer: Single two-stage venous cannula
A two-stage venous cannula has drainage holes at the tip (draining the IVC) and mid-section (draining the right atrium), providing adequate venous return through one cannulation site.
Question 5: For which type of cardiac procedure is bicaval cannulation with separate SVC and IVC cannulas specifically required?
- Isolated coronary artery bypass grafting
- Isolated aortic valve replacement
- Open right heart procedures such as tricuspid valve repair or ASD closure (Correct answer)
- Descending thoracic aortic aneurysm repair
Correct answer: Open right heart procedures such as tricuspid valve repair or ASD closure
Bicaval cannulation isolates both venae cavae with snares when the right atrium must be opened, keeping the right heart bloodless and dry for tricuspid valve or septal defect repair.
Question 6: What is the primary purpose of an aortic root vent placed during CPB?
- To administer antegrade cardioplegia exclusively
- To decompress the left heart and remove accumulated air before cross-clamp removal (Correct answer)
- To continuously monitor aortic root pressure
- To drain the right atrium during bypass
Correct answer: To decompress the left heart and remove accumulated air before cross-clamp removal
The aortic root vent removes air from the aortic root and decompresses the left-sided heart during bypass, preventing air embolism when cardiac ejection resumes.
CVP CVP Cannulation Techniques and Circulatory Support 1
What is the most common site for arterial cannulation in standard cardiopulmonary bypass?