PG Seminar presentation

1. AMRUTA N. PAI

2. Cardio Pulmonary Bypass Machine

3. CPBM
 Also known as a heart-lung machine.
 It is a device that does the work of the heart & lungs when the
heart is stopped for a surgical procedure, or for other reasons.
 Most patients are on the pump only as long as it takes to complete
open heart surgery.

4. Components of CPBM
 2 main functional units-
 Pump
 Oxygenator
 Tubing (silicone rubber or PVC)
 Pumps (roller, centrifugal)
 Oxygenator (membrane oxygenators, oxygenation)
 Cannulae (Venous, Arterial)

6. Working schema of CPBM
Special tubing connected to
large blood vessels
Allows oxygen-depleted
blood to leave the body
Travels to CPBMMachine oxygenates the blood
Returns blood to the body
through a second set of tubing Constant pumping of the machine
Pushes the oxygenated blood
through the body

8.  Tubes- placed away from the surgical site- do not interfere with the
surgeon‟s work
 Placed in a blood vessel large enough to accommodate tubing & pressure of
pump.
 2 tubes insure- blood leaves the body before reaching the heart & returns to
the body after the heart, giving a still & mostly bloodless area to operate.
 Third tube- inserted very near or directly into the heart, but not connected to
the CPBM- used to flush heart with cardioplegic, a potassium solution
which stops the heart.
 Once the cardioplegic takes effect, the CPBM is initiated and takes over the
heart and lung function.

9. Purpose of CPBM
 To stop the heart without harming the patient (oxygenated blood must
continue to circulate through the body during surgery)
 The pump does the work of heart (pumping blood through body) and
fulfils the function of lungs (oxygenates the blood while pumping)
 The CPBM is used for 2 primary reasons:
 Many cardiac surgeries would be impossible to perform with the
heart beating- “moving target” - significant blood loss.
 The pump is used not for surgical need, but to help out if a patient has
heart failure. In some cases, a heart failure patient may be placed on
the pump to support the patient until a heart transplant becomes
available.

10. Risks- CPBM
 Formation of small blood clots in blood processed by machine- can
probably cause stroke, MI or renal failure on returning to body's
bloodstream.
 The machine can also trigger an inflammatory process that can damage
many of the body's systems and organs, called „post-pericardiotomy
syndrome‟.
 Post-operative bleeding may be a serious complication, occasionally
requiring a return to the operating room.
 Problems with temporary confusion or memory loss.

11. History
Definition & Introduction
Procedure
Recent advances in CABG
Indications
Contraindications
Complications

12. History of CABG
 John Gibbon- clinically useful cardiopulmonary bypass (CPBM)- 1953
 William Mustard- first direct surgical approach to coronary circulation-1953
 Dr. Robert Goetz & Dr. Michael Rohman- first successful surgeons to
perform CABG with donor vessel anastomosed to the RCA. The actual
anastomosis with the Rosenbach ring developed an atheromatous plaque-
occluded the origin of the IMA used.
 Russian cardiac surgeon, Dr. Vasilii Kolesov- first successful IMA-
Coronary artery anastomosis in 1964.
 1970‟s- first full decade of CABG (relieved angina & improved QoL)

13. Alternative terminologies
 Heart Bypass
 Bypass surgery
 Aorto Coronary Bypass (ACB)
 “Cabbage”
 Single bypass, Double bypass, Triple bypass, Quadruple bypass
and Quintuple bypass

14. Definition
CABG is a surgical procedure in which one
or more blocked coronary arteries are bypassed
by a blood vessel graft to restore normal blood
flow to the heart, with an intent to relieve
angina & prevent death.
Arteries or veins from elsewhere in the
patient's body are grafted to the coronary
arteries to bypass atherosclerotic narrowing's
and improve the blood supply to the coronary
circulation supplying the myocardium.

15. Introduction

16. 2 stages to bypass surgery:
 Stage 1: healthy blood vessel (the graft) is removed from leg or chest wall.
 Stage 2: Connecting graft to coronary artery, „bypassing‟ diseased
segment, improving the blood supply to the heart.
1 of the following technique is used:
i) A heart-lung machine is used to circulate blood around the body, allowing
the surgeon to operate on the heart (“On-pump” surgery)
ii) The „beating heart‟ technique, where the surgery is performed while the
heart is still beating and working. This is called „off pump‟ surgery.
The operation usually takes between3-6 hours
Procedure

18. General anaesthesia is administered Removes the veins or prepares
the arteries for grafting
Saphenous vein or internal mammary
artery, incisions are made
Incision from patient's
neck to navel
Sawed through breastbone Retracts rib cage & exposes heart
Connected to CPBMCardioplegic solution injected
through coronary root
Small opening- just below blockage
in diseased coronary artery
Blood redirected through this
opening once the graft is sewn

19.  Cardioplegic solution avoids tissue damage, lowers the temperature of
heart
 Most patients who undergo CABG, have at least 3 grafts done.
 CABG builds a detour around one or more blocked coronary arteries
with a graft from a healthy vein or artery.
 The graft goes around the clogged artery (or arteries) to create new
pathways for oxygen-rich blood to flow to the heart.
 Electric shocks start the heart pumping again after grafting
 The heart-lung machine is turned off & after the normal bloodflow is
resumed, the chest cavity is closed.

21. Recent advances in CABG
 Totally endoscopic, minimally invasive CABG with use of a surgical
robot, doesn't require an incision and patients can often return to
normal activities in few weeks.
 Keyhole surgery : requires 2-3 inch incision instead of splitting chest
open.
 Hybrid procedures (minimally invasive bypass surgery and stented
angioplasty in one operation).
 Off-pump or "beating heart" bypass

22. Difference- “Off-pump CABG”
 The bypass is sewed onto the heart, while heart continues beating.
Various types of heart stabilizers are used to restrain the heart one section
at a time so the surgeon can operate on it.
 The chest is opened through a midline sternotomy incision. After the
target coronary vessel is exposed & stabilized, it is occluded & opened.
 A bridging plastic tube - which allows blood flow during suturing -- may
be placed. The bypass graft is then sutured to the coronary artery.

24. Advantages of off-pump over on-pump CABG
 Reduced need for blood transfusions
 Reduced risk of bleeding, stroke and kidney failure
 Potential for reduced psychomotor and cognitive problems
 High-risk patients with additional diseases like lung disease,
kidney failure and peripheral vascular disease may benefit from
this kind of operation.

25. Indications
 The 2004 ACC/AHA CABG guidelines state CABG is preferred
treatment for
 Disease of the left main coronary artery (LMCA).
 Disease of all three coronary vessels (LAD, LCX and RCA).
 Diffuse disease not amenable to treatment with a PCI.
 The 2005 ACC/AHA guidelines further state:
CABG is preferred treatment with other high-risk patients such as
those with severe ventricular dysfunction (i.e. low ejection fraction), or
diabetes mellitus.

26. Indications….. contd…..
 Significant (>50%) left main stem stenosis.
 Disabling angina despite maximal medical therapy (surgery can be
performed with acceptable risk)
 3 vessel disease (survival benefit greater when LVEF < 50%).
 2 vessel disease with significant proximal LAD stenosis & either
EF < 50% or demonstrable ischemia on non-invasive testing.

27. Contraindications
 Absence of an open major artery 1 mm or more in diameter beyond the
obstructing lesion
 Absence of viable myocardium in the area supplied by the stenosed artery
 Co-existing severe non-cardiac condition with poor prognosis

28. Complications
Immediate Complications
 Bleeding
 Infection- chest and leg or arm wounds, or lungs
 Myocardial Infarction
 Pain
 Death
 Irregular heart beat
Long Term Complications
 Stroke
 Renal failure

29. Introduction
Indications
Contraindications
Repair, replacement
Types of valvular prosthesis
Complications

30. Introduction
 4 valves in the heart.
 Valves are strong, thin flaps of
tissue, called leaflets.
 The leaflets open to allow blood
to move forward through the
heart during half of the
heartbeat, and close to prevent
blood from flowing backward
during the other half of the
heartbeat.

31.  The tricuspid valve allows blood to move
from the upper chamber of the heart, the
right atrium, into the lower chamber, the
right ventricle.
 The pulmonic valve allows blood to
move out of the right ventricle, which
pumps blood to the lungs. After
absorbing oxygen from the lungs, the
blood flows back into the heart to the left
atrium.
 The mitral valve allows blood to move
from the left atrium into the left
ventricle.
 The aortic valve allows the blood to
move out of the left ventricle, which
pumps the blood out of the heart, to the
rest of the body.

32. Indications
Acquired valvular diseases
 Infection
 Infective endocarditis
 Rheumatic fever
 Structural valve changes
 Stretching or tearing of the
chordae tendineae or
papillary muscles
 Fibro-calcific degeneration
 Dilatation of the valve
annulus.
Congenital valvular diseases
 Improper valve size
 Malformed leaflets
 Irregularity in the way the
leaflets are attached
 Congenital valve diseases
 Bicuspid aortic valve disease
 Mitral valve prolapse

35. Contraindications
 Manifestation of end-stage valve
disease
 Very poor LV function in
association with a regurgitant
lesion
 Severe fixed pulmonary
hypertension
 Extensive extra-annular tissue
destruction due to uncontrolled
endocarditis
 Old age
 Presence of co-morbidities
 Renal failure
 Advanced pulmonary disease
 Severe haemolytic anaemia
 Severe generalized
arteriopathy
 Malignant disease
 Extreme overweight
 Serious infection until
eradication

36. Valvular heart
surgeries
Repair Replacement

37. Valve repair V/S Valve replacement
The potential advantages of valve repair versus valve replacement are:
Decreased risk of infection
Decreased need for life-long anticoagulant medication
Preserved heart muscle strength

38. Types of Valve Repair Surgeries
 Commissurotomy
 Decalcification
 Annulus support
 Creation of new chords
 Quadrangular resection of leaflet
 Patched leaflets and bicuspid aortic valve repair

39. Consists of separating mitral valve leaflets by mechanical means (valve “dilator”)

42. Valve Replacement Surgery
Removal of faulty valve (native valve) and replace it
by sewing a mechanical or biological valve to the
annulus of the native valve.
Biocompatible
Aortic valve replacement- most commonly done
Anticoagulant medications (Warfarin) - rest of the
patient‟s life, depending on the type of valve
replacement that was used- reduces probability of
heart attack or stroke
Need to do regular blood test (PT, INR)

44. Types of Valvular prosthesis
BIOLOGICAL VALVES
MECHANICAL VALVES

45. Biological valve
 Biological valves (tissue or
bioprosthetic valves)- made from
bovine, porcine & allograft or
homograft.
 May have some artificial parts to give
the valve support and to aid placement
 Do not need life-long anticoagulant
therapy after Sx
 May last at least 17 years without a
decline in function

46. Homograft valve
• Human heart valve obtained from a
donor after death, frozen & then
transplanted in recipient
• Used to replace a diseased aortic valve,
or pulmonic valve during the Ross
procedure
• Well tolerated by the body as they are
most like native valves
• Do not need to take anticoagulant
medications for rest of their lives

47. Mechanical Valves
Made totally of mechanical parts- tolerated
well by the body.
Made of metal or carbon, designed to perform
functions of the patient‟s native valve.
Very durable, designed to last a lifetime.
The bi-leaflet valve is the most common type
of mechanical valve
Consists of 2 carbon leaflets in a ring covered
with polyester knit fabric.
Need to take anticoagulant medications for the
rest of their lives
Some patients who have a mechanical valve
replacement report a valve clicking noise at
times (opening and closing)

48. Types of mechanical valves
Ball prostheses
Non-hooked single-disk prostheses
Non-hooked double-disk prostheses
Disadvantage - must be associated to prescription of an anticoagulant treatment
in long-term

49. Used to treat aortic valve disease
Patient‟s own pulmonic valve is removed
and used to replace a diseased aortic
valve.
The pulmonic valve is then replaced by a
homograft valve.
Do not need to take anticoagulant
medications for rest of their lives.
Ross Procedure

50. Smaller incisions than traditional heart
valve surgery
Other techniques- endoscopic or keyhole
approaches (also called port access,
thoracoscopic or video-assisted surgery)
and robotic-assisted surgery
Benefits-
a smaller incision (3 to 4 inches-
instead of 6- to 8-inch incision with
traditional surgery)
smaller scars
 reduced risk of infection
 less bleeding
 less pain & trauma
decreased length of stay in the hospital
(3 to 5 days) & decreased recovery time
Minimally Invasive Valve Surgery

52. Full recovery from valve surgery takes about 2-3 months
To maintain cardiovascular health after surgery, making lifestyle changes
& taking medications- strongly recommended
Lifestyle changes include:
Quitting smoking
Treating high cholesterol
Managing high blood pressure & diabetes
Exercising regularly
Maintaining a healthy weight
Eating a heart-healthy diet
Participating in a cardiac rehabilitation program, as recommended
Following up with your doctor for regular visits
Recovery process

53. Complications
 Structural valve deterioration
(biological & bioprosthetic valves, deterioration is time-dependent)
 Valve thrombosis
 Thromboembolism
 Prosthetic endocarditis
 Major bleeding
 Paravalvular leak

54. Thank You…….