CARDIO PLEGIA DELIVERY DR NIKUNJ R SHEKHADA (MBBS,MS GEN SURG,DNB CTS SR)

1. METHODS OF PLEGIA DELIVERY
BY DR NIKUNJ
(CTS RESIDENT STAR HOSPITAL)
(Coordinator:DR P.SATYENDRANATH PATHURI)
(30/10/18)

2. • Based on the concentrations of sodium and potassium ions.
• EXTRACELLULAR solutions contain high levels of potassium, magnesium and
sodium, while
• INTRACELLULAR solutions contain low electrolyte levels. Intracellular solutions
mimic the high potassium/low sodium conditions reducing potential concentration
gradients across the plasma membrane, thereby halting potassium efflux. This
reduction in membrane potential resting state prevents generation of action
potentials.
• The function of the Na+/K+ ATPase channel is reduced in hypothermic conditions,
therefore permitting the intracellular concentrations to persist.
• Extracellular cardioplegia on the other hand works by preventing repolarization of
myocytes. Potassium rich perfusate in the extracellular space reduces the
membrane voltage difference causing depolarization
• Intracellular calcium sequestration occurs via active transport across an ATP-
dependent pump allowing relaxation of the myocardium in diastole.
• Repolarization however is prevented by the high potassium concentration of the
cardioplegic solution.

3. METHODS OF DELIVERY
• INTERMITTENT ANTEGRADE
• ANTEGRADE VIA THE CORONARY
BYPASS GRAFTS
• CONTINUOUS ANTEGRADE
• CONTINUOUS RETROGRADE
• INTERMITTENT RETROGRADE
• ANTEGRADE FOLLOWED BY
RETROGRADE
• SIMULTANEOUS ANTEGRADE AND
RETROGRADE

4. • Clinical studies show that switching from antegrade to retrograde
perfusion increases oxygen uptake and lactate washout, indicating that
each mode perfuseses diffrerent areas. there fore, both antegrade and
retrograde perfusions are required

5. ANTEGRADE CARDIOPLEGIA

6. ANTEGRADE CANNULA
• An antegrade cannula is placed high in the ascending aorta below the proposed
site of the aortic cross-damp.
• 4-0 purse-string suture with a tourniquet is used to secure the cannula
• After commencement of CPB, the heart should empty, as indicated by the collapse
of the pulmonary artery, indicating good systemic venous drainage. The aorta is
clamped, and antegrade cardioplegia is delivered for 2 minutes at a rate of 200
ml/min.
• In coronary bypass procedures additional antegrade cardioplegia is hand delivered
through the saphenous vein graft

7. ANTEGRADE CARDIOPLEGIA
• by use of a catheter or needle, in the ascending aorta has been the initial, traditional
approach.
• DIFFICULTIES
• (1) rupture of an atherosclerotic plaque at the insertion site, resulting in either
microemboli or aortic dissection;
• (2) aortic insufficiency, resulting in ventricular dilation and inadequate flow into the
coronary arteries;
• (3) left main ostial, occlusive, and variable coronary artery obstructions, leading to
cardioplegic maldistribution;
• (4) enlargement of the catheter-induced aortic opening at the insertion site, particularly
in association with a thin-walled aorta related to poststenotic aortic dilation.

8. RETROGRADE PERFUSION OF THE CORONARY SINUS

9. RETROGRADE PERFUSION OF THE CORONARY SINUS
• Retrograde perfusion of the coronary sinus, initially described by Pratt, was first
used clinically by Lillehei and colleagues.
• Reported use of retrograde perfusion to protect heart during aortic valve surgery
• retrograde perfusion improves subendocardial perfusion
•

10. RETROGRADE CANNULA
• malleable stylet and inflating balloon cannula. A high atrial 4-0 purse-string suture
is placed from the right side of the operating table.
• cannula should always enter the coronary sinus easily. cannula is advanced 2 to 3
cm within the coronary sinus. position is confirmed with ECHO images, the
presence of dark blood emerging from the cannula, and the appropriate antegrade
and retrograde delivery and a monitoringin infusion system.

11. RETROGRADE PERFUSION OF THE CORONARY SINUS
• Method r introducing the retrograde cannula from the right side of the operating
table. Note the direct course at 45 degrees from the coronary sinus to the junction
of the coronary sinus and the left atrium.

12. CORONARY SINUS PRESSURE
• Coronary sinus pressure ranges from 30 to 40 mmHg at an infusion rate of 200 to
250 ml/min.
• A coronary sinus pressure of >50 mmHg means improper positioning or cardiac
retraction that kinks the venous system.
• this is treated by reducing the flow rate immediately, repositioning the catheter,
and resuming flow
• Balloons should not be moved during infusion because of coronary sinus wall
traction and possible injury.
• Coronary sinus pressure of < 20 mmHg implies that the balloon is not inflated or
not occluding the coronary sinus.

13. ADVANTAGES OF RETROGRADE PERFUSION
• (1) distribution of the cardioplegic solution to myocardial segments perfused by
obstructed or occluded coronary arteries or the internal mammary artery during redo
coronary surgery;
• (2) avoidance of the need for direct coronary ostial cannulation, with its attendant
traumatic injury and subsequent stenotic potential, in performing aortic root
procedures;
• (3) ability to administer cardioplegia during mitral valve surgery without removal of the
retractor
• (4) ability to provide continuous cardioplegia
• (5) avoidance of debris and subsequent embolization from atheromatous vein graft
material during re-do coronary surgery.

14. DISADVANTAGE
• (1) slowness in achieving diastolic arrest if it is used for the initial introduction of
cardioplegia,
• (2) occasional difculty in blind insertion of the catheter into the coronary sinus,
• (3) easy dislocation of the catheter into the right atrium despite the use of ribbed
balloon-tipped catheters,
• (4) traumatic injury and perforation during insertion of the catheter and
occasionally spontaneous rupture of the great cardiac vein in fragile older patients
even with autoinflatable balloon-tipped catheters, and
• (5) inadequate perfusion of the right ventricle and posterior ventricular septum
• Major technical issues include the requirement to measure coronary sinus
pressure constantly to avoid infusion pressures exceeding 30 mm Hg and never to
exceed an infusion rate greater than 200 mL/min because venovenous
anastomoses and shunts at higher ows will direct more than 60% of the potential
“nutrient flow” into the ventricular cavities through the thebesian channels

15. CORONARY SINUS INJURY
• coronary sinus can be injured due to forceful cannulation or continued adminis
tration of cardioplegia when coronary sinus pressure exceeds 50 to 60 mmHg.
• perfusionist notes high pressure, and then low pressure as a consequence of
acute perforation, or the surgeon sees red blood accumulation within the
pericardial well during infusions.
• Perforation can be repaired directly with 6-0 prolene sutures or with a pericardial
patch

16. SIMULTANEOUS DELIVERY OF CARDIOPLEGIC PERFUSATE
Tubing use for antegrade, retrograde, and vein perfusion connected to the retrograde arm. Note the stopcock that allows simultaneous delivery
of cardioplegic perfusate and monitoring of arterial or coronary sinus pressure. the arm is connected to the retrograde limb, allowing
simultaneous retrograde/ antegrade perfusion down the vein graft or right coronary ostium during aortic valve replacement.

17. INTERMITTENT/CONTINUOUS INFUSION
• CONTINUOUS CARDIOPLEGIC perfusion has been advocated to avoid
ischemia by antegrade or retrograde delivery, but adequate protection
may not be achieved at usual flow rates and vision becomes obscured
during infusion.
• INTERMITTENT replenishment restores hypothermia, maintains
electromechanical arrest, flushes accumulated metabolites, and
counteracts acidosis and edema.

18. • Initially, the heart is arrested with high dose potassium (20 to 40 mEq/L) blood
cardioplegia ,
• and low-dose cold potassium (8 to 10 mEq/L) blood cardioplegia is used for
intermittent repeat doses. Such reinfusions (every 15 to 20 minutes) are
retrograde, directly into the aorta or, via the each coronary ostium.
• Cold blood with a hematocrit of appro mately 20% is infused at a pressure of <40
mmHg and infused for a duration of 2 minutes.
• At the completion of the cardiac procedure, controlled reperfusion is achieved by
administering a dose of warm cardioplegia ("hot shot"), administered either
antegrade, retrograde, or both. is can be followed by a continuous infusion of
warm blood into the aortic root while the crossclamp is still in place at a flow
of300 to 350 ml/min with a pressure of 80 mmHg.
• aorticclamp is released within 5minutes after adequate contractility is observed.

19. • Sites for venting the left ventricle. A: Aortic root cannula; one limb of the "Y" is connected to the
cardioplegia administration system and the other limb to suction (siphon or roller pump) for venting left
heart. B: Cannula inserted at the junction of the right superior pulmonary vein (RSPV) and left atrium and
advanced through the left atrium and mitral valve (mv) into the left ventricle. C: Cannula is inserted
directly into the apex of left ventricle. D: Cannula is inserted into the pulmonary artery. AO, aorta; PA,
pulmonary artery; LA, left atrium; RV, right ventricle; LV, left ventricle. (Modified from Reed CC, Stafford
TB. Cardiopulmonary bypass , 2nd ed. Houston: Texas Medical Press, 1985:277, with permission.)
•

21. Thank you