Intra-aortic Balloon Counter Pulsation in Cardiac Surgery

1. IABP
Presenter : Dr Debmalya Saha
Moderator : Prof (Dr.) Subodh Satyarthy

2. Introduction
• Intra-aortic balloon counterpulsation(IABP) is an invasive device, the initial
step in mechanical ventricular support
• Hemodynamic support and/or control of ischemia both before and after
surgery
• In contrast to most inotropic agents,IABP provides physiologic assistance to
the failing heart by
①decreasing myocardial oxygen demand( LV afterload)
②improving diastolic coronary perfusion.

3. INDICATIONS
• Ongoing ischemia refractory to medical therapy/hemodynamic compromise
prior to urgent or emergent surgery
• Prophylactic placement for high-risk patients with critical CAD (usually left
main disease) or severe LV dysfunction
• High-risk patients undergoing off-pump surgery(lateral wall or posterior
wall grafting)
• Unloading for cardiogenic shock or mechanical complications of MI (acute
MR,ventricular septal rupture,arrythmias,ventricular aneurysms)
• Postcardiotomy low cardiac output syndrome unresponsive to moderate
doses of multiple inotropic agents
…..contd

4. INDICATIONS
• Postoperative myocardial ischemia.
• Acute deterioration of myocardial function to provide temporary support or
serve as a bridge to cardiac transplantation

5. CONTRAINDICATIONS
• Aortic regurgitation
• Aortic dissection
• Severe aortic and peripheral vascular atherosclerosis (balloon can be
inserted via the ascending aorta during surgery).

6. PRINCIPLES
• Reduces the impedance to LV ejection (“unloads the heart”) by rapid
deflation just before ventricular systole
• Increases diastolic coronary perfusion pressure by rapid inflation just after
aortic valve closure and improves ITA and graft diastolic flow
• Reduces the time-tension index (systolic wall tension) and increases the
diastolic pressure-time index, favorably altering the myocardial oxygen
supply: demand ratio.
• Improve left ventricular diastolic function after surgery
• The utility of IABP in patients with predominantly RV failure is most likely
based upon improvement in RV perfusion from diastolic augmentation
along with improvement in LV function from unloading

7. INSERTIONTECHNIQUES
• Placed through the femoral artery with the balloon situated just distal to the
left subclavian artery so as not to impair flow into the left internal thoracic
artery.Generally, a 40 cc balloon is selected for most patients,reserving
smaller (25 or 34 cc) balloons (which have a shorter balloon length) for
smaller patients, usually women.
• Seldinger technique:Percutaneous insertion of balloon through a sheath (as
small as 7.5 Fr) over a guidewire.
• Sheathless systems are preferable in patients with peripheral vascular
disease and diabetes
• Surgical insertion by exposing the femoral artery and placing the balloon
through a sidearm graft or directly into the vessel through an arteriotomy or
a percutaneous sheath
• Alternative cannulation sites in patients with severe aortoiliac disease
include the ascending aorta, subclavian artery, and brachial artery.

8. IABPTIMING
ECG
• Inflation : peak of the T wave at the
end of systole
• Deflation : just before or on the R
wave
• The use of bipolar pacing
eliminates the interpretation of
pacing spikes as QRS complexes by
the console
Arterial waveform
• Inflation : at the dicrotic notch
• Deflation : just before the onset of
the aortic upstroke.
• Especially useful in the operating
room, where electrocautery may
interfere with the ECG signal

9. Intra-aortic balloon pump
(IABP) timing: synchronization
with the cardiac cycle. Arterial
pressure waveform with
correct IABP timing
A-one complete cardiac cycle;
B-unassisted aortic end-diastolic pressure;
C-unassisted systolic pressure;
D-diastolic augmentation;
E-reduced aortic end-diastolic pressure;
F-reduced systolic pressure

11. IABP monitor showing the ECG, arterial pressure tracing with balloon
augmentation,
and balloon inflation/deflation pattern

12. IABP Problems & Complications
1.Inability to balloon
a.Unipolar atrial pacing
b.Rapid rates- atrial fibrillation
c.Arrythmias- atrial & ventricular ectopics
d.Volume loss – leaks,improperly unwrapped balloon
e.Balloon rupture – Rx: immediate balloon removal
contd. . .

13. 2.Vascular complications
a.Catastrophy- dissection,rupture,paraplegia
b.Embolization- mesenteric,renal,cerebral circulations
c.Distal ischaemia – most common complication (10-15%)
Rx: IV heparin with target aPTT 1.5-2 times control
3.Thrombocytopenia
mechanical destruction of circulating platelets due to inflation-
deflation.Daily platelet count to be done.

14. WEANING OFTHE IABP
1.Satisfactory cardiac output with minimal inotropic support
ADR @1 micgm/min or DOPA/DOBU @ 5micgm/kg/min
2.Earlier- Complications
a.Distal ischaemia
b.Balloon malfunction
c.Thrombocytopenia
d.Infection

15. • Weaning is initiated by decreasing the inflation ratio from 1:1 to 1:2 for
about 2–4 hours, and then to 1:3 or 1:4 (depending on which console device
is used) for 1–2 more hours. Once it is determined that the patient can
tolerate a low inflation ratio with stable hemodynamics, the IABP should be
removed.
• If there is an anticipated delay in removal of more than a few hours for
manpower reasons or because of the need to correct coagulopathy, the
ratio should be increased to at least 1:2 to prevent thrombus formation.
• The operative mortality for patients receiving a prophylactic IABP is less
than 5%,but it rises to about 30% for patients requiring postcardiotomy
support.

16. IABP RemovalTechniques

17. • Surgical removal should be considered in patients with small or diseased
vessels and in those with very weak pulses or Doppler signals with the
balloon in place.The need for a thrombectomy and embolectomy may be
anticipated in these patients. If the IABP has been in place for more than 5
days, percutaneous removal can be performed, but there is a greater chance
that surgical repair of the femoral artery may be required.
• Coagulation parameters must be checked and corrected before
percutaneous removal or the patient may require groin exploration for
persistent hemorrhage or a false aneurysm.

18. THANK
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