Q8. Which ofthe following are not used in cardioplegic solution
A) potassium
B) procaine
C) calcium
D) blood
Q9. Best suited graft for anastomoses of left anterior descending artery is
A) saphenous vein graft
B) left internal thoracic artery
C) right internal thoracic artery
D) radial artery graft
Q10. Which of the following is not an indication of re exploration of a patient after CABG
a Mediastinal drain output more than 500 ml in the 1st hour
b Drain output of 200 ml in 2 hours.
c Pericardial tamponade
d Large hemothorax
Answers
8)c
The cardioplegic solution arrests the heart in diastole and is required to decrease the oxygen consumption of the heart.
The solution consists of hyperkalemic crystalloid. Blood maybe added if haematocrit is less than 25 percent.
9) b
Left internal thoracic artery when anastomosed with LAD has a patency rate of 90% at 10 years.
Great saphenous vein is the commonly used conduit and 50% are patent after 15 years.
10) b
2-3% of patients require reexploration for bleeding after CABG .
The increased risk is due to hepatinization, hypothermia, CPB (coronary pulmonary bypass) and protamine.
Persistent blood loss of 200 ml / 4 hrs is an indication for surgery.
All the above statements except (b) are true.
Also CPB (coronary pulmonary bypass) machine use is associated with increased risk of bleeding, neuro cognitive dysfunction, thromboembolism, fluid retention and reversible organ dysfunction. The levels of neutrophil elastase, interleukin 8, C3a and C5 a are also increased in CPB leading to higher rates of infection.
Advantages of OPCAB (off pump coronary artery Bypass)
1. Less blood loss
2. Less ICU and Hospital stay
3. Less neurocognitive dysfuncti
Notes
Newer advances in Coronary Revascular techniques
1. Robotic Intervention
Da Vinci surgical robots for harvesting Internal thoracic artery and CABG
2. Transmyocardial LASER Revascularization
