Cardiac Operations and Cardiopulmonary

bypassProf. Ahmed DeebisHead of Cardiothoracic Surgery Department- Zagazig University

Cardiac Operations

Types of cardiac operations1- Extracardiac Operations

2- Closed Cardiac Operations

3-Open Heart Surgery

1- Extracardiac Operations

• Carried out on the main vessels outside the heart

• Usually performed without cardiopulmonary bypass

• Examples:Pericardiectomy, Ligation of patent ductus arteriosus, Repair of aortic coarctationPalliative procedures for congenital heart diseases

2- Closed Cardiac Operations

• Blind procedures performed by the finger of the surgeon or by an instrument placed inside the heart

• Examples:closed mitral commissurotomy (valvotomy )for mitral

stenosis• These operations are rarely done in current era,

and have replaced with open heart surgery techniques or endovascular catheter-based procedures.

3-Open Heart Surgery• During these operations the heart functionally

disconnected from the circulations, an artificial heart lung machine (cardiopulmonary bypass, extracorporeal circulation) do the function of the heart and the lung temporarily

• The operations performed under direct vision in a bloodless field within the chambers of the heart or great vessels

• Classically performed through median sternotomy excellent exposure

Cardiopulmonary Bypass (CPB) OR

“heart–lung machine”

Cardiopulmonary Bypass (CPB) • Definition:

CPB is a technique that temporarily diverting blood from heart and lungs and provides oxygenation and pump functions in the presence of a still bloodless heart.

• Uses: CPB is used in heart surgery requiring arrested heart either with or without opening of cardiac chambers to support the circulation during that period.

Cardiopulmonary Bypass (CPB), cont.

• Haw?1) Heparinization, 2) Using priming fluids, 3) Cannulation, and 4) Myocardial protection

• 1) Heparinization: heparin dose of 300 U/kg (reversed by protamine sulfate after weaning from CPB and removal of cannulae)

• 2) Using priming fluids: to augment peripheral circulation and to decrease blood viscosity

Cardiopulmonary Bypass (CPB), cont.

3) Cannulation:1) Arterial Cannulation: cannula is inserted usually in Aorta (some cases in femoral artery)

2) Venous Cannulation: usually double cannulation in SVC and IVC (sometimes single cannulation in R.A)

Cardiopulmonary Bypass (CPB), cont.

4) Myocardial protection• After aortic cross–clamping cardioplegic solution

injected either in proximal Aorta (antegrade), Or in coronary sinus (retrograde).Cardioplegia

• 1) Cold, Tepid or Iced. Recently there is also warm blood cardioplegia which is mainly used in our center.

• 2) High potassium (K) content.• N.B The time from beginning CPB to its end is called CPB

Time, while time from aortic cross clamping till aortic de-clamping is called ischemic time.

Cardiopulmonary Bypass (CPB), cont.

Complications of cardiopulmonary bypass:• Prolonged bypass induces cytokine activation

and inflammatory response results in: red cell damage and haemoglobinuria, thrombocytopenia, clotting abnormalities, Reduced pulmonary gas exchange, andCerebrovascular accidents

Minimal invasive cardiac Surgery • Median sternotomy is the standard approach for

open heart surgery, • But ,also other approaches can be used as i) Right sbumammary thoracotomy for ASD closure

and mitral valve surgery, ii) Limited left anterior thoracotomy for bypassing a

stenosed left anterior descending coronary artery with left internal thoracic( mammary) artery.

• The main disadvantage of these incisions is the small field they yield, that is insufficient in emergency situations.

Surgery for Valvular Heart Diseases

Prof. Ahmed Deebis

Head of Cardiothoracic Surgery Department.

Zagazig University

Valvular Anatomy

Types of Valve Disease

• Valvular heart diseases includes valvular stenosis and valvular regurgitation (incompetence) or both Valvular stenosis: When a valve opening is smaller

than normal Valvular regurge : occurs when a valve does not

close tightly, thus allowing blood to leak backwards.

Both valvular diseases can involve all four valves

What Are The Causes Valvular Disease?

• Congenital : Mostly affect the aortic or pulmonary valve

• Acquired : Due to a variety of diseases or infections leading to changes in the structure of the valve as:

Rheumatic fever , Endocarditis, Coronary artery disease, Myxomatous degeneration Cardiomyopathy (heart muscle disease), or Connective tissue diseases

Rheumatic heart diseases are the commonest cardiac lesions in Egypt.

• Chronic stage of rheumatic heart disease produce permanent dysfunction, in the form of valvular stenosis, valvular incompetence or both.

• The most affected valve is the mitral valve followed by the aortic valve.

• Rheumatic tricuspid valve lesions are rare and rheumatic pulmonary valve lesions are extremely rare.

Diagnosis

Clinically : Symptoms & Signs.Chest X-ray & ECGTrans-thoracic Echocardiography (TTE): routinely for

diagnosis of valvular heart lesions & to assess the severity of the lesions.

Trans-esophageal Echocardiography (TEE): detection of thrombotic or vegetative deposits, and malfunctioning prosthetic valve.

Coronary angiography: indicated to detect associated coronary artery lesions in patients over 40 years of age.

Mitral Stenosis

• Almost caused by rheumatic heart disease.• Progressive obstruction of the mitral valve causes

increased L A pressure reflected to the pulmonary circulation ---- pulmonary Hypertension.

• Common symptoms : Congestive symptoms (dyspnea on exertion, orthopnea and paroxysmal nocturnal dyspnea), Palpitation, hemoptysis.

• May be complicated with AF , may lead to LA thrombus formation & thromboembolism

Indications for Surgery in MS

• Sever mitral stenosis with mitral valve area less than 1.2 cm2 (normally 4-6 cm2).

• Moderate mitral stenosis with paroxysmal nocturnal dyspnea, or orthopnea despite adequate medical therapy.

• History of A F and/or systemic emboli (from LA thrombus)

• Worsening pulmonary hypertension

Surgical Options for M S

Percutaneous balloon mitral valvuloplasty: • Needs good leaflet pliability, minimal chordal

thickening and intact subvalvular mechanism. • Contraindicated if left atrial thrombus present.Open mitral commissurotomy• For patients with mild calcification and mild

leaflet/chordal thickening.Mitral valve replacement• For moderate to severe calcification with severely

scarred valve leaflets or subvalvular apparatus

Mitral Regurgitation

• Primarily caused by rheumatic heart disease, but may be congenital, infective endocarditis , ischemic heart disease, or myxomatous degeneration

• Blood flows back into the left atrium during systole• During diastole the regurge output flows into the LV

and increases the volume into the LV• Progression is slowly – fatigue, chronic weakness,

dyspnea, anxiety, palpitations• May develop AF and LV failure• May develop right sided failure as well

The New York Heart Association (NYHA) Functional Classification

N.B.: Heart disease must be present Symptoms (undue fatigue, palpitations, dyspnea and/or anginal pain)

Indications for surgery in MR

• Patients in NYHA class III-IV• Patients in NYHA class I-II symptoms with

onset of AF or evidence of deteriorating LV function.

• Acute MR associated with CHF, cardiogenic shock, or papillary muscle rupture

Surgical Options for MR

Mitral Valve Repair: • Myxomatous degeneration of the MV is ideal for

repair.• Ischemic mitral regurge• Selected cases of rheumatic etiology.Mitral valve replacement• If satisfactory repair can not be accomblished

(heavily calcified annulus, or valve)• Patients with MR due to rheumatic heart disease are

more likely to need MV replacement

Advantages of valve repair versus replacement

• Lack of need for chronic anticoagulation. • Elimination of prosthesis-related complications.• Low rate of endocarditis.

Aortic Valve Disease

• Most patients with aortic valve disease indicated for surgery require aortic valve replacement.

• Aortic valve repair had a limited role in aortic valve surgery ( only in selected cases).

Indications for surgery for Aortic Stenosis(AS)

• Symptomatic patients with mean valve gradient of over 50 mmHg or valve area less than 0.8 cm2 (normal 3-4 cm2).

• Asymptomatic patients with significant stenosis and Left Ventricular Hypertrophy(LVH).

Indications for surgery for Aortic Regurgitation (AR)

• Patients in NYHA class III-IV symptoms, • Evidence of Left Ventricular decompensation

in asymptomatic patient (Echo Data)Ejection Fraction (EF) less than 55%, End-diastolic dimension of the left ventricle more

than 70 mm, End-systolic dimension of the left ventricle more

than 55 mm

Choice of Valve Prosthesis2 types of prosthetic valves, mechanical Valves

and bioprosthetic valves

Mechanical ValvesThese have many designs, e.g., •Caged ball (Starr-Edwards), •Tilting monoleaflet, and •Tilting bileaflet valves.

•The commonly used now are the tilting bileaflet valves.•The patients should be anticoagulated usually with warfarine with a target INR between 2.5 to 3.5.

Bioprosthetic valves

•Valve leaflets are either porcine, bovine, or human from fresh cadavers. •The valve is suspended on a prosthetic ring to allow it to be sewn in place. •The patient does not need long-term anticoagulation, but the durability of the valve is shorter than prosthetic valves.

Common types of heart valve prostheses: Bileaflet (top left); Starr-Edwards ball and cage (top right);

tilting monoleaflet disc (bottom right); stented porcine prosthesis (bottom left).

Mechanical Valve vs. Bioprosthetic Valve

Mechanical Valve Long durability Long-term anticoagulation

with warfarine. Target INR: 2.5-3.5

Increased risk of thromboembolism (1-3%/year).

Increased risk of hemorrhage: 1-2% /year

Bioprosthetic Valve Short durability Usually long-term

anticoagulation not needed.

Low risk of thromboembolism

Low risk of hemorrhage

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