From: Miniaturized cardiopulmonary bypass: the Hammersmith technique
mCPB | cCPB | ||
---|---|---|---|
Venous cannula | 29 Fr OptiFlow (Sorin) | 34/46 Fr 2-stage (Medtronic) | |
Advantage | • Multi-stage and longer length (increasing drainage and structural support in IVC) | • Convenient and easy placement | |
• Less prone to collapse and blockage due to side holes and grooves | • This type of cannulae is used in common practice | ||
Disadvantage | • Rigid (requiring careful placement) as it extends further down the IVC | • Larger – increased risk of interaction with IVC/RA wall | |
• 2 stage cannula less support in IVC thus more prone to collapse and decreased drainage from Hepatic veins and circulation | |||
Venous line and drainage | 3/8 inch tubing | ½ inch tubing | |
Advantage | • Smaller, active kinetic drainage | • Gravity syphon based | |
• Monitored controlled drainage | • Simple, standard and convenient | ||
• Tailored to patient specific venous collapse pressure | |||
Disadvantage | • Uncontrollable | ||
• Not routinely monitored | |||
VARD | Advisable to use in mCPB but not compulsory | VARD is not required due to the presence of the Venous reservoir but it has been proven to be of benefit in all CPB circuits [8]. However, it is not commonly used. | |
Advantage | • Enhances safety | • Cheaper | |
• Efficient gross air removal | • Simple open system | ||
• Active micro air removal | • The reservoir filters and removes gross air easily | ||
• Decreases FSA versus standard filters used in CPB venous reservoir’s | • Continuity | ||
• All air introduction into system | |||
Disadvantage | • Require perfusion experience | • No active removal of micro-embolic air (just passive) | |
• Extra Component of circuit | • Venous reservoir in series (continued FSA exposure) | ||
• Vented blood has to be manually returned back into the systemic system | • Increases FSA | ||
Reservoir* | SSR or Midi card | Venous reservoir (Sorin Evo) | |
Advantage | • Closed (no ‘in series’ blood-air interface- limits FSA exposure) | • Open | |
• Decreased damage to blood cells | • Common practice | ||
• Optimises vent management | • Venting possible | ||
• Midi card ‘in parallel’ automatic air removal | • Low Pressure Suction and blood venting possible | ||
• | • Vented blood is automatically returned to the systemic circulation | ||
Disadvantage | • SSR requires manual air bubble removal | • ‘In series’ Blood-air interface | |
• No Low Pressure Suction (an issue in cases where there are high volumes of LPS) | • Damage to blood cells | ||
• Vented blood has to be manually returned back into the systemic circulation | • Disguises poor suction/vent management | ||
Centrifugal pump | Revolution (Stöckert, Germany) | Standard roller pump | |
Advantage | • Non-occlusive | • ½ inch silicon tubing | |
• Pressure regulates | • Cost-effective | ||
• Gross safety mechanism | |||
• Less blood cell trauma | |||
Disadvantage | • Cost and training | • Occlusive (No pressure regulation) | |
Heat exchanger and oxygenator | Eos (Sorin Group, Italy) | Avant (Sorin Group, Italy) | |
Advantage | • 1.1 m2 (decreased) FSA | • High ‘factor of safety’ | |
• Efficient use of fibre bundle capacity | • 7.5 L/min blood flow | ||
• high ratio of gas exchange surface area to FSA | |||
Disadvantage | • Reduced (but acceptable) ‘factor of safety’ | • 1.8 m2 FSA | |
• Excessive ‘factor of safety’ for our patient population | |||
Arterial line filter | Pall AL6 low prime | Pall AL6 low prime |