1. OP CAB :-
Techniques and outcome
-DR MANOJ P NAIR
Lead Consultant(Cardio Thoracic Surgery)
Aster Medcity,Cochin,South India.

2. • 1951 Vineburg implanted the internal mammary
artery into the myocardium
• First successful OPCAB was performed in 1961
and Kolesov in 1964 performed the first
successful anastomosis of left internal
mammary
• Outshone by the development of CPB

3. • Resurgence of technique in 1980s in isolated
centers especially with limited resources
• On pump CABG Vs OPCAB- controversial &
focus of discussion in the field of cardiac
surgery .

4. • OP CAB is essentially coronary artery bypass
grafting without the help of cardio pulmonary
bypass

5. Placement of graft to more than one of the three
major coronary arteries is safely possible with
stabilization devices which keep the operating
area of the heart still

6. Stabilizers…

10. ON PUMP OFF PUMP
Evolved methodology Evolving methodology
Conduct of operation and
preoperative selection “ well
defined “
Still incompletely defined
and still evolving

11. Anaesthetic Management
“Close communication between surgeon
and Anaesthesiologist”

12. Surgeon to Anaesthesiologist
• Positioning of heart
• Displacement of Heart
• Shunt placement
• Coronary artery occlusion

14. Anesthesiologist to Surgeon
• Ischemic changes in ECG
• ECG amplitude may be severely decreased
• ST segment changes may be underestimated
• TEE to determine RWMA and right and left
ventricular volumes

15. Surgical steps
• Median sternotomy
• Conduits harvested:saphaneous vein, internal thoracic
artery, radial artery..
• Heparinization done after the completion of mammary
artery dissection
• Pericardium opened,stay sutures placed
• In older patients epicardial ultrasound of Ascending aorta

16. Heparin
• Protocol varies from institution to institution
• Minimum of 5000 U to full heparinization (3mg/kg)

17. Heparin Reversal
With protamine
• No administration
• Partial
• Full dose

18. Temperature management
• Hypothermia should be avoided
• Normothermia with warm IV fluids
and irrigation fluids
• Warming blanket or mattress
• Humidification of airway
• Warm temperature in operating room

19. Surgical Technique
To maintain hemodynamic stability
• Positioning-Trendelenburg position – Increasing
preload
• Rotation of Operating table
• Opening of Right pleura

20. Surgical technique continued..
• Opening right pericardium vertically
• Minimize the manipulation of heart
• Optimal exposure of lateral wall of heart
• Ventricular pacing to prevent bradycardia while RCA
grafting

21. Pre op insertion of IABP
• Increase the tolerance of manipulation of heart
in high risk patients

22. Exposure of LV surfaces
• Apex of heart towards ceiling
• Lateral displacement
• Apex to right or left

24. Use of stay sutures
• Stay sutures are placed in the posterior
pericardium opposite the oblique sinus(most
dependent part of the pericardial cavity)

25. Continued….
• Should avoid injury to aorta and esophagus
• Adjust orientation of the snares
• Circumferential pressure on the heart should be
avoided

26. Myocardial protection in OP CAB
• Brief coronary occlusion to visualize vessels-
Regional- Global dysfunction
• Olden days-Intermittent pharmacologic arrest
+profound bradycardia
• Ischemic preconditioning

27. Myocardial protection..
• Fluids and vasopressors
• good exposure of target vessels
• Selection of order of anastomosis
• Intracoronary shunts
• PADCAB

28. Exposure of RCA or PDA
• Marked elevation of apex of the heart with minimal
lateral displacement
• Using Octopus and or starfish

29. PDA position

30. Exposure of distal RCA
• Leftward traction
• Table left and Trendelenburg position

31. Exposure of LAD
Left and upward towards the head

32. Exposure of OM
• Elevation of the apex and lateral displacement
to the right
• Pericardial and right pleural openings
• Table rightward and Trendelenburg position

33. Sequence of grafting
• LIMA to LAD
• Vein/radial to the OM
• Proximal anastomosis
• Vein/radial to PDA or RCA
• Proximal anastomosis

34. General guideline
• Graft the artery that has the evidence of
collateral blood supply to the distal arterial bed
• Vessels without demonstrable collateral blood
supply are grafted last

35. OP CAB Vs ON PUMP
• Numerous studies and few conclusions
• Meta analysis
• Large retrospective studies
• Randomized trials

36. Evolving trends
• Less blood loss and transfusion requirements
• Less myocardial enzyme release in 24 hours
• Less early Neurocognitive disorders.
• Same length of hospital stay,mortality rate
• Same long term neurological function
• Cardiac outcome

37. • Quality of life
• In severely calcified Aorta where clamping can
cause direct neurological complications
• Large scale prospective studies are needed
• Still “evolving”

38. Findings favoring OP CAB
• Probably less bleeding
• Probably less renal dysfunction
• Probably less short term NCD,especially if aorta
is calcified
• Possibly shorter overall length of hospital stay

39. Findings favoring On Pump CABG
• Less technically demanding
• Shorter “learning curve”
• Possibly better long term graft patency
• Easier to graft posterior (Cx) Bypass targets
• Probably more bypass grafts constructed
ref: Circulation 2005

40. Current indications for OP CAB
• Age 70 years
• Low ejection fraction
• Reoperative surgery
• Patients with significant comorbidities
• Cerebral vascular disease
• Peripheral vascular disease

41. Current indications..
• Hepatic disease
• Bleeding disorders
• COPD
• Renal dysfunction
• Atheromatous or calcified aorta
• Patients who refuse blood products

42. • Duration – 10 years
• Total No – 2098
• Standard CABG - 1617
• OP CAB – 481
• Mortality in standard CABG - 6.8
• Mortality in OP CAB - 1.7
Selection of patients in OP biased
SINGLE SURGEON EXPERIENCE

43. Conclusion :
• Both OP CAB and standard CABG give excellent
results
• Neither should be judged,inferior to the other

44. Thank You