Cardio Thoracic & Vascular Surgery

The heart contains contains four  valves -Tricuspid valve, pulmonary valve, mitral valve, aortic valve.

• REGURGITATION
• STENOSIS
• ATRESIA
  

• The procedure of choice for correcting severe mitral regurgitation
• The aim is to restore a large surface of leaflet coaptation, to preserve leaflet mobility.
• MV repair surgery is recommended for patients who are asymptomatic or symptomatic with severe mitral regurgitation.
• Mitral valve repair is superior to Mitral Valve Replacement in better preservation of LV function, avoidance of prosthesis-related events (hazards of anticoagulation, the short life span of bioprosthesis), and reduced hospital mortality.

The general principles of MV repair are to create an apposition of the anterior and posterior leaflet in systole, increase the valve mobility, prevent valve Stenosis, reduce the annular dilatation and remove all the infective foci in case of endocarditis. Stabilization of the annulus with an annuloplasty ring.

The presence of significant annular calcification; valvular dystrophic, inflammatory, or infective changes; subvalvular thickening or fusion; and progressive cardiomyopathy is an indication for primary mitral valve replacement.

During mitral valve replacement, the surgeon removes the part of the native diseased mitral valve and replaces it with a mechanical valve or a tissue valve.

Age >65 years: Tissue valve
Age <65 years: Mechanical valve, in a patient with no contraindication for oral anticoagulation

• No opening of the chest or cutting of bones
• Faster recovery
• Less pain
• Lower risk of complications
• Decreased blood loss and need for blood transfusion
• Minimal scarring
• Shorter hospital stay
• Early return to work

MICS

A new valve is inserted into the heart to treat aortic stenosis, without removing the Diseased aortic valve.

• The TAVI can be considered for symptomatic patients between 65-80 yrs.
• Asymptomatic patients with severe AS <80 years with EF <50%.
• Severe symptomatic AS patients who are at high risk for AVR.

CONTRAINDICATIONS:

• Estimated life expectancy less than 1year
• Inadequate annulus size (<18 mm, >29mm)
• Active endocarditis
• Symmetric valve calcification
• The short distance between the annulus and the coronary ostium
• Plaques with mobile thrombi in the ascending aorta.
• Pure aortic valve regurgitation
• Bicuspid aortic valve
• Associated ascending aortic enlargement

Major advantage of TAVI :

• Surgical repair requires a long incision down the chest wall, whereas TAVI requires just a small incision & a flexible catheter to reach the aorta.
• The expensive procedure with no significant advantage over surgical replacement in the majority of patients.

Coronary artery disease is the most common type of heart pathology affecting patients.

RISK FACTORS

SYMPTOMS AND SIGNS:

1. Chest Pain
2. Breathlessness
3. Fatigue
4. Heart attack

TYPES :

• Stable Angina - relieved by rest and medications
• Unstable Angina - It’s further referred as NSTEMI with an elevation of cardiac enzymes and no ECG changes
• Acute Coronary Syndrome (STEMI) - involves ECG changes and elevation of enzymes.

DIAGNOSIS :

• ECG
• TMT
• Echocardiogram
• Coronary Angiogram
• CT Coronary Angiogram

INDICATIONS FOR SURGERY:

• Left main disease greater than 50%.
• Three-vessel coronary artery disease of greater than 70% with or without proximal LAD involvement.
• Two-vessel disease: LAD + one major artery.
• One or more significant stenosis greater than 70% in a patient with significant anginal symptoms despite maximal medical therapy where percutaneous procedures are not possible.
• One vessel disease greater than 70% in a survivor of sudden cardiac death with ischemia-related ventricular tachycardia where percutaneous treatment is not possible.
• Coronary Disease with associated valve pathology.

SURGICAL MANAGEMENT:

• CABG - CORONARY ARTERY BYPASS GRAFT
• OPCAB- OFF PUMP CORONARY ARTERY BYPASS GRAFT
• MICAS – Minimally Invasive Coronary  Artery Surgery 

CLINICAL BENEFITS:

1. Offers a safe alternative to on-pump CABG
2. Provides an effective option for high-risk patients.
3. Diminishes the need for inotropes and blood products.
4. Reduces the incidence of atrial fibrillation
5. Complete revascularisation and equivalent patency rates are possible in OPCAB
6. Enables a decreased incidence of intraoperative aortic dissection (IAD) after open heart surgery when a no-touch aortic technique is used.

Minimally invasive direct coronary artery bypass (MIDCAB) grafting is the technique to achieve revascularization of the anterior wall of the left ventricle using the left internal mammary artery (LIMA) as the bypass graft to the left anterior descending (LAD) artery, vein, radial artery for other vessels.

The procedure performed through a left anterior mini-thoracotomy has been proposed as a less invasive in alternative to full sternotomy revascularization of all stenosed vessels.

CONTRAINDICATIONS:

• Diffusely diseased vessels.
• Poor LV function.
• RCA  grafting
• Very obese and very thin patients
• Concomitant valve surgery.

COMPLICATIONS OF CABG:

• Stroke
• Renal Failure
• Arrhythmia
• Bleeding
• Infections
• Heart Failure

CABG is superior to PCI with stents in: 

• Triple vessel disease
• Double vessel disease with proximal LAD
• Left main disease
• Diabetic patients with diffuse coronary artery disease.
• When dual antiplatelet therapy is contraindicated
• Small vessels 

It is defined as the structural-functional or positional defect of the heart after birth Signs and symptoms for CHDs depend on the type and severity of the particular defect. Some defects might have few or no signs or symptoms. Others might have the following symptoms:

• Blue-tinted nails or lips
• Fast or troubled breathing
• Tiredness when feeding
• Sleepiness

ASD

Atrial septal Defect -It is a defect in the atrial septum that allows the shunting of blood from left to right atrium.

TYPES

Types of atrial septal defects include:

• Secundum. This is the most common type of ASD occurs in the middle of atrial septum
• Primum. This type of ASD affects the lower part of the atrial septum . Babies with primum ASDs may also have other heart defects, such as  endocardial cushion defect and is mostly associated with Down syndrome.
• Sinus venosus. This rare type of ASD usually occurs in the upper part of the wall separating the heart chambers.  This type is linked with defects in the right pulmonary vein or large veins in the heart called superior or inferior vena cava.
• Unroofed Coronary sinus.  is the rarest type of ASD and involves a missing or incomplete wall between your coronary sinus (a group of veins connected to your heart) and your left atrium.

DIAGNOSIS :

• Chest X-ray
•  ECG  
•  Trans thoracic echocardiogram
•  Transesophageal echocardiogram

INDICATION FOR SURGERY

All patients with isolated ASD  at any age should undergo ASD closure.

ASD CLOSURE 

• SECUNDUM  ASD - Percutaneous device closure Surgical closure if rims are  inadequate

• PRIMUM  ASD - Surgical closure with mitral valve repair   

• SINUS VENOSUS TYPE - Surgical closure with rerouting of partially anamolous pulmonary veins

• CORONARY SINUS ASD - Surgical closure with patch diverting coronary sinus to right atrium

It is defined as the defect in the ventricular septum which leads to shunting of the blood between the left and the right ventricle.

TYPES OF VSD

• Membranous:  This is the most common type of VSD which occurs in  the upper section of ventricular septum
• Muscular: Present in  muscular part of the ventricular septum 
• Inlet: defect is present  just below the tricuspid valve and the mitral valve 
• Outlet (conoventricular): the defect is below the pulmonary and aortic valves

DIAGNOSIS

• Chest X-Ray
• Electrocardiogram 
• Trans thoracic echocardiogram
• Transesophageal echocardiogram
• Cardiac catheterization

INDICATIONS FOR VSD CLOSURE 

• Symptomatic  Patients
• Asymptomatic patients with evidence of LV volume overload 
• History infective endocartitis
• VSD associated with Aortic valve insuffiency

SURGICAL CLOSURE OF VSD

• VSD’s are unlikely to close after 4 years of age.
• Depending upon the size of the VSD, direct or patch closure of the defect is decided.

Complications 

• Eisenmenger syndrome
• Aortic insufficiency due to prolapse of the aortic valve leaflet
• Endocarditis
• Embolization

Tetralogy of Fallot is a combination of four congenital heart defects.

The four heart defects of tetralogy of Fallot include:

1. Pulmonary stenosis:   narrowed pulmonary valve 
2. Ventricular septal defect (VSD): VSD is a hole in the ventricular septum
3. Overriding Of aorta: is due to displacement of the outlet septum into the right ventricle, 
4. Right ventricular Hypertrophy : thickening of the right ventricle 

Signs and symptoms of tetralogy of Fallot at birth may include:

• Cyanosis - bluish discoloration of skin,lips and nail beds
• Clubbing
• Heart murmur
• Trouble feeding or gaining weight
• Difficult or rapid breathing
• Fatigue

DIAGNOSIS

Diagnosis  before birth -  prenatal ultrasounds

After birth, tests for TOF may include:

• Chest X-ray –boot shaped heart 
• Echocardiogram (echo)
• Electrocardiogram (ECG)
• Cardiac catheterization

TREATMENT

All children with tetralogy of Fallot need surgery. 

Palliative Shunt 

Blalock-Taussig shunt, is a palliative procedure done  to increase pulmonary arterial blood flow.

 In a modified BT shunt a Gore-Tex tube graft is placed between the subclavian artery and the pulmonary artery, 

In central shunt a Gore-Tex tube  is placed between the ascending aorta and the pulmonary artery

 A shunt operation is not permanent; patient with a shunt  requires corrective procedure later.

CORRECTIVE SURGERY

A full tetralogy of Fallot repair surgery involves:

• Placing a patch over the ventricular septal defect
• Infundibular resection
• Widening the pulmonary outflow tract

COMPLICATIONS

• Abnormal heart rhythm (arrhythmia)
• Heart failure
• Endocardititis
• Regurgitation from  the repaired pulmonary valve

An aortic aneurysm is a bulge in the aorta. Aneurysm may rupture or split, causes internal bleeding or block the flow of blood from the heart to various parts of the body.

WHAT IS AN AORTIC ANEURYSM?

An aortic aneurysm develops when there is a weakness in  the wall of the aorta. In aneurysm, there is dilation of aorta more than 1.5 times of its normal size.

TYPES:

1. ABDOMINAL AORTIC ANEURYSM (AAA) : 

      Involves the abdominal part of the aorta

2. THORACIC AORTIC ANEURYSM (TAA) : 

• Involves the aorta anywhere from its origin above the heart upto the diaphragm
• Commonly associated with marfan’s syndrome

WHAT IS THE INCIDENCE OF THORACIC AORTIC ANEURSYSM?

• Ascending Aortic Aneursym : 60%
• Descending aorta : 40%
• Arch aneurysm : 10%
• Thoraco abdominal : 10%

WHAT ARE THE RISK FACTORS FOR AORTIC ANEURYSM?

• Smoking
• Age above 65
• Male gender
• Family history
• Hypertension

WHAT  ARE THE CAUSES AORTIC ANEURYSM ?

• Atherosclerosis
• Marfan syndrome and Ehlers-Danlos syndrome
• Injury to an aorta
• Infections, such as syphilis
• Inflammation of the arteries

WHAT ARE THE SYMPTOMS OF AN AORTIC ANEURYSM ?

Most of the patients are asymptomatic until it ruptures.  

Sudden rupture of aortic aneurysm include symptoms like :

• Dizziness or lightheadedness.
• Rapid heart rate .
• Severe chest pain, 
• Abdominal pain or back pain.

HOW IS AORTIC ANEURYSM DIAGNOSED ?

Most of the aneurysms are asymptomatic and are diagnosed  during a routine checkup or screening.

Imaging tests that helps in the diagnosis of an aortic aneurysm are

• CT scan
• CT or MRI angiography
• Ultrasound 

HOW IS AN UNRUPTURED AORTIC ANEURYSM TREATED?

The Physician may prescribe medications to improve bloodflow, lower blood pressure and control cholesterol. This helps slow aneurysm growth and reduces pressure on the artery wall. And also recommend regular screenings. 

All thoracic aneurysm with diameter of  > 5cm should be operated.                                                                                                                                                                                         

WHAT ARE THE TYPES OF AORTIC ANEURYSM SURGERY? 

Bentall’s procedure: for ascending aortic aneurysm, involves replacement of diseased aortic valve .

For descending aortic aneurysm, diseased aorta is grafted with a dacron graft.

COMPLICATIONS 

• Leaking blood around the graft.
• Formation of blood clots.
• Infection.

• Abrupt onset of severe pain in the chest, back, or abdomen. 
• Loss of consciousness 
• Shortness of breath, 
• Pain in the arms or legs, 

• X-ray
• Transesophageal echocardiogram.
• CT Scan
• Magnetic Resonance Imaging (MRI)

Treatment:

• Once the patient is diagnosed with aortic dissection, the goal is to control the tear by reducing the blood pressure and to decide whether surgery is required or not.
• All patients with acute Ascending aortic dissection needs emergency  surgery 
• In case of  descending aorta  dissection surgery is recommended, if  the aorta ruptures or vital organs perfusion is  reduced.
• Surgery incolves replacing the dissected part of the aorta with a synthetic material(Dacron graft),there by preventing the blood flow to the false lumen. 
• The risk of mortality for acute type A aortic dissection is approximately 20%. 

• Multiorgan failure
• Stroke
• MI
• Paraplegia
• Renal failure
• Bowel ischemia
• Tamponade
• Acute aortic regurgitation
• Death