Coronary Artery Bypass Surgery in India

Narrowing of the coronary arteries by atherosclerosis (fatty deposits, calcium, cholesterol and blood clots) is known as coronary artery disease. This may be chronic and cause symptoms such as chest pain (angina) and breathlessness on exertion; or acute, causing acute myocardial infarction (heart attack).

Coronary artery bypass grafting restores blood flow to the heart muscle by adding a bypass graft (vein or artery) to bypass the blocked area. This surgery is usually done through an incision down the middle of the breastbone, called a median sternotomy, but can occasionally be done through an incision below the nipple on the left side, called a thoracotomy.

You may be connected to a heart lung machine (cardiopulmonary bypass) to maintain blood flow to the rest of the body while your heart is stopped to allow the bypass grafts to be sewn onto the coronary arteries. Alternatively, the bypass grafts may be constructed by stabilising the heart with special instruments while it is still functioning (beating heart surgery). Your surgeon will decide which is the most appropriate technique for you.

Coronary artery bypass graft surgery (CABG) involves sewing one end an artery or vein above a blocked coronary artery and the other end below the blockage, thereby allowing blood an alternative means to get to the heart. The arteries or veins used for the bypass (which are known as "grafts") are usually obtained from the leg or the chest wall. Bypass surgery may not be possible if the coronary artery is heavily calcified or if the disease is very widespread. CABG can be done with or without connecting the patient to heart-lung machine, depending on the kind of blockages and surgeon's decision.

Several new surgical approaches are being developed, which can potentially reduce the discomfort and complications associated with traditional bypass surgery. These are collectively referred to as being "minimally invasive." In general, these approaches focus on performing bypass surgery though a very small chest incision and performing bypass surgery while the heart is still beating (ie, without the need for a heart/lung bypass machine).OPCAB (Off Pump Coronary Artery Bypass)

The bypass surgery done without connecting the patient to of heart-lung machine or pump is called OPCAB.

MIDCAB (Minimally Invasive Direct Coronary Artery Bypass)

Bypass surgery done through a small cut (incision) in the lower part of the sternum (chest bone) only, rather than full cut across it. This type of surgery, which is possible in selected cases only, is associated with a small scar, lesser pain and faster recovery. Alternatively, this surgery can also be done through a small cut on the left side of the chest.

The location and degree of coronary artery blockages are determined before surgery by using a procedure called heart catheterization, or coronary angiogram. This procedure provides an outline, like a road map, of the arteries of the heart.

Factors favoring bypass surgery -

Bypass surgery is often recommended over angioplasty when the left main coronary artery is narrowed by more than 50 percent, when angioplasty does not relieve angina, when many arteries are narrowed, or when the heart's left ventricular pumping function is substantially impaired. Bypass surgery is also preferred over angioplasty in diabetic patients who have two or three vessels involved.

Benefits -

Bypass surgery can very effectively relieve angina and can even prolong life in people with severe coronary heart disease, such as those with three-vessel involvement associated with impaired left ventricular pumping function. However, the success of bypass surgery on symptoms and on survival depends upon several factors, including the pattern and extent of arterial narrowing, the general progression of coronary heart disease over time, and the blood vessels used for bypass. In general, bypass surgery is more likely than angioplasty to provide complete revascularisation.

About 95 percent of people who have narrowing of several arteries have improvement or complete relief of their angina immediately after surgery. About 85 to 90 percent of people remain angina-free at one to three years after surgery, and about 75 percent of people remain angina-free or free of major coronary events at five years after surgery. By 10 years, about one-half of all grafted vessels become narrowed or occluded, and by 15 years, about 85 percent of grafted vessels become narrowed or occluded. These late events usually require a second surgery

Recovery from bypass surgery -

It usually takes a while to recover from even routine bypass surgery. However, about 70 to 80 percent of people who have this surgery are eventually able to return to work; this is about the same as the percentage of people who are treated medically and are able to return to work. Factors that appear to have a role in a person's ability to return to work are the presence or absence of angina after surgery, employment status before surgery and income, the function of the heart's left ventricle, and age.

Heart Valve Surgery in India

There are four valves inside the heart to allow blood to pass in one direction only. Occasionally these valves may become narrowed, causing obstruction to the flow of blood (stenosis) or may leak, allowing blood to flow backwards within the heart (insufficiency). This affects the efficiency of the heart's function. Occasionally these valves may be damaged by infection (endocarditis). The two most commonly involved valves are the aortic and the mitral valves. The aortic valve will usually be replaced. The mitral valve is frequently suitable for repair but, if this is not possible, a replacement will be undertaken.

There are two types of replacement valves. One is a tissue valve (bioprosthesis) made from the aortic valve of a pig or the sack around the heart of a cow (pericardium). The other type is a mechanical valve that is made from a very durable material called pyrolytic carbon. Your surgeon will decide with you the type of valve that is most suited to your requirements.

It is essential to use the heart lung machine (cardiopulmonary bypass) for heart valve surgery.

Aortic Surgery in India

The aorta is the main blood vessel that runs from the heart supplying blood to every organ in the body. Occasionally the aorta can become diseased by dilating or enlarging (aneurysm) or by splitting, separating into an inner and outer layer (dissection). Surgery is then undertaken to replace the segment of diseased aorta. The approach may be through the sternum or through an incision in the left chest (thoracotomy). The heart lung machine (cardiopulmonary bypass) is usually required for this type of surgery. Your surgeon will discuss this in greater detail with you. Preparation for and recovery is similar to that of coronary artery bypass or valve surgery.

Enhanced external counterpulsation

Enhanced external counterpulsation (EECP) is a procedure performed on individuals with ischemic cardiomyopathy in order to diminish the symptoms of their ischemia. In various studies, EECP has been shown to relieve angina, improve exercise tolerance, and decrease the degree of ischemia in a cardiac stress test

Method

While an individual is undergoing EECP, they have pneumatic stockings (also known as cuffs) on their legs and are connected to telemetry monitors that monitor their heart rate and rhythm. The most common type in use involves three cuffs placed on each leg (on the calfs, the lower thighs, and the upper thighs (or buttock)). The cuffs are timed to inflate and deflate based on the individual's electrocardiogram. The cuffs should ideally inflate at the beginning of diastole and deflate at the beginning of systole. During the inflation portion of the cycle, the calf cuffs inflate first, then the lower thigh cuffs and finally the upper thigh cuffs. Inflation is controlled by a pressure monitor, and the cuffs are inflated to about 300 mmHg.

When timed correctly, this will decrease the afterload that the heart has to pump against, and increase the preload that fills the heart, increasing the cardiac output. In this way, EECP is similar to the intra-aortic balloon pump (IABP). Since it increases pressure in the aorta while the heart is relaxing (during diastole) EECP also increases blood flow into the coronary arteries, which also occurs during that phase.

Treatment regimen

While the number of EECP treatment sessions vary widely, one widely used regimen in the United States is a total of 35 one hour sessions; One session a day, five days a week, for 7 weeks. This particular regimen is used because it is the regimen studied in the MUST-EECP trial, the first prospective, randomized-control multi center trial on EECP.

There are no clear guidelines on how often the treatment can or should be performed. An individual who has shown benefit with the regimen but later begins having complaints attributable to his ischemic cardiomyopathy may benefit from repeated procedures.

Indications for use

EECP is usually reserved as a "last resort" treatment of individuals with symptoms of ischemic cardiomyopathy who are not amenable to percutaneous coronary intervention or coronary artery bypass graft surgery. It is typically only performed on individuals who continue to have symptoms while on the maximum tolerated doses of conventional medications. To meet these criteria, the individual must have coronary artery disease that includes at least one vessel with at least a 70 percent obstruction. In addition, the individual must have evidence of either an infarction or significant ischemia on a stress test with some form of imaging (ie: nuclear or echocardiographic imaging).

In addition, individuals with advanced heart failure due to an ischemic etiology may benefit from EECP. This is the object of the PEECH trial, a large multi-center currently ongoing study. 5

Physiological considerations

As mentioned above, the deflation of the cuffs at the beginning of systole will decrease the afterload that the heart has to pump against. Because of this, myocardial oxygen demand (the amount of oxygen required by the heart to function properly) will decrease during the EECP session. This is a relatively short-term improvement, however, and is limited to the session of EECP.

The inflation of the cuffs during diastole (when the aortic valve is closed) increases blood flow to the myocardium (the muscle of the heart). This is because, unlike the tissues of the rest of the body, the myocardium receives the majority of its blood during diastole. The increased flow during diastole caused by EECP is believed to promote the formation of collateral arteries in the coronary circulation.

Presumably, it is these newly opened collateral arteries that produced the sustained benefit that EECP provides to individuals after the EECP sessions are complete. While EECP has been in use since the 1980s, the mechanism in which it provides a lasting clinical benefit is still poorly understood. One theory is that EECP exposes the coronary circulation to increased shear stress, and that this results in the production of a cascade of growth factors that result in angiogenesis.

Hemodynamic effects

The acute hemodynamic effects of EECP are transitory and only occur during a treatment session. These effects are also related to the number of cuffs that are placed on each leg. It has been shown that if only calf and lower thigh cuffs are used, flow is increased by 19 percent compared to baseline. Addition of the upper thigh (buttock) cuffs increases the flow to 26 percent over the baseline.

EECP increases cardiac output by a combination of the increased preload and the decreased afterload during the EECP session. Inflation of the cuffs during diastolecompresses the venous system in the legs, causing increased venous return to the heart, thereby increasing left ventricular preload. This increased filling of the left ventricle increases cardiac output. Deflation of the cuffs in systole decrease afterload (the pressure the left ventricle has to overcome in order to eject blood), also increasing the cardiac output.

There are long term hemodynamic effects of EECP, which are presumably due to the decreased ischemic burden noted in individuals after completing an EECP regimen. These include a decrease in the left ventricular end diastolic pressure (LVEDP), and subsequently a decreased in brain natriuretic peptide (BNP) levels, and improved diastolic performance of the left ventricle.

Contraindications

Similar to the intra-aortic balloon pump, contraindications to EECP include severe peripheral vascular disease and significant aortic insufficiency. Other contraindications include:

• Significant unprotected left main disease
• Atrial fibrillation
• Overt congestive heart failure
• Any severe valvular heart disease
• Uncontrolled hypertension (blood pressure > 180/100 while on medications)
• Phlebitis
• Deep vein thrombosis
• Lower extremity stasis ulcers
• Bleeding diathesis (including INR > 2.0)
• Pregnant or potentially pregnant women

Atrial fibrillation is a relative contraindication, because the varying heart rate makes it impossible to time the inflation and deflation of the cuffs. In the subset of individuals with atrial fibrillation, high degree heart block, and a permanent pacemaker who are pacemaker dependent, it may still be possible to perform EECP.

Percutaneous coronary intervention

Percutaneous coronary intervention(PCI), commonly known as coronary angioplasty, is an invasive cardiologic therapeutic procedure to treat thestenotic (narrowed)coronary arteries of the heart. These stenotic segments are due to the build up of cholesterol-laden plaques that form due to coronary heart disease.

Percutaneous coronary intervention can be performed to reduce or eliminate the symptoms of coronary artery disease, including angina(chest pain), dyspnea (shortness of breath) on exertion, and congestive heart failure. PCI is also used to abort an acute myocardial infarction, and in some specific cases it may reduce mortality.

Procedures

The term balloon angioplasty is commonly used to describe percutaneous coronary intervention, which describes the inflation of a balloon within the coronary artery to crush the plaque into the walls of the artery. While balloon angioplasty is still done as a part of nearly all percutaneous coronary interventions, it is rarely the only procedure performed.

Other procedures that are done during a percutaneous coronary intervention include:

• Implantation of stents
• Rotational or laser atherectomy
• Brachytherapy

Endarterectomy

Endarterectomy is a surgical procedure to remove the atheromatous plaque material, or blockage, in the lining of an artery constricted by the buildup of fatty deposits. It is carried out by separating the plaque from the arterial wal.

It was first performed on a superficial femoral artery in 1946 by the Portuguese surgeon João Cid dos Santos. In 1951, E. J. Wylie, a north-american, performed it on the abdominal aorta. The first successful reconstruction of the arotid artery was performed by Carrea, Molins, and Murphy in Argentina, later in the same year.

The procedure is widely used on the carotid artery of the neck as a way to reduce the risk of stroke, particularly when the carotid artery is narrowed by more than 70%. A carotid endarterectomy may itself cause a stroke at the time of operation, which is why it is not performed prophylactically in asymptomatic patients.

Endarterectomy is also used as a supplement to a vein bypass graft to open up distal segments.

Some forms of pulmonary hypertension may be amenable to endarterectomy of the pulmonary artery. This is a highly specialized procedure.

The term atherectomy is used to describe reconstruction through a catheter

Angioplasty

Angioplasty is the mechanical widening of a narrowed or totally-obstructed blood vessel. These obstructions are often caused by atherosclerosis.

The term "angioplasty" is a portmanteau of the words "angio" (from the Latin/ Greek word meaning vessel) and "plasticos" (Greek: fit for moulding). Angioplasty has come to include all manner of vascular interventions typically performed in a minimally-invasive or "ercutaneous" method

Coronary angioplasty

A coronary angiogram (an X-ray with radio-opaque contrast in the coronary arteries) that shows the left coronary circulation. The distal left main coronary artery (LMCA) is in the left upper quadrant of the image. Its main branches (also visible) are the left circumflex artery (LCX), which courses top-to-bottom initially and then toward the centre/bottom, and the left anterior descending (LAD) artery, which courses from left-to-right on the image and then courses down the middle of the image to project underneath of the distal LCX. The LAD, as is usual, has two large diagonal branches, which arise at the centre-top of the image and course toward the centre/right of the image.

A coronary angiogram (an X-ray with radio-opaque contrast in the coronary arteries) that shows the left coronary circulation. The distal left main coronary artery (LMCA) is in the left upper quadrant of the image. Its main branches (also visible) are the left circumflex artery (LCX), which courses top-to-bottom initially and then toward the centre/bottom, and the left anterior descending (LAD) artery, which courses from left-to-right on the image and then courses down the middle of the image to project underneath of the distal LCX. The LAD, as is usual, has two large diagonal branches, which arise at the centre-top of the image and course toward the centre/right of the image.

Percutaneous coronary intervention

Coronary angioplasty, also known as "percutaneous transluminal coronary angioplasty", was first developed in 1977 by Andreas Gruentzig. The procedure was quickly adopted by numerous cardiologists, and by the mid-1980's, many leading medical centers throughout the world were adopting the procedure as a method to avoid bypass surgery.

Angioplasty is sometimes eponymously referred to as Dottering, after Dr Charles Theodore Dotter, who, together with Dr Melvin P. Judkins, first described angioplasty in 1964. As the range of procedures performed upon lumens of coronary arteries has widened, the name of the procedure has changed to percutaneous coronary intervention (PCI).

Sometimes a small mesh tube, or "stent", is introduced into the blood vessel or artery to prop it open using percutaneous methods. Angioplasty with stenting is a viable alternative to heart surgery. It has consistently been shown to reduce symptoms due to coronary artery disease and to reduce cardiac ischemia, but has not been shown in large trials to reduce mortality due to coronary artery disease, except in patients being treated for a heart attack acutely (also called primary angioplasty). There is a small but definite reduction of mortality with this form of treatment compared with medical therapy, which usually consists of the administration of thrombolytic ("clot busting") medication.

Procedure

The angioplasty procedure usually consists of most of the following steps:

• Access into the femoral artery in the leg (or, less commonly, into the radial artery or brachial artery in the arm) is created by a device called an "introducer needle". This procedure is often termed percutaneous access.
• Once access into the artery is gained, a "sheath introducer" is placed in the opening to keep the artery open and control bleeding.
• Through this sheath, a long, flexible, soft plastic tube called a "guiding catheter" is pushed. The tip of the guiding catheter is placed at the mouth of the coronary artery. The guiding catheter also allows for radiopaque dyes (usually iodine based) to be injected into the coronary artery, so that the disease state and location can be readily assessed using real time x-ray visualization.
• During the x-ray visualization, the cardiologist estimates the size of the coronary artery and selects the type of balloon catheter and coronary guide wire that will be used during the case. Heparin (a "blood thinner" or medicine used to prevent the formation of clots) is given to maintain blood flow.
• The coronary guide wire which is an extremely thin wire with a radiopaque flexible tip that is inserted into through the guiding catheter and into the coronary artery. While visualizing again by real-time x-ray imaging, the cardiologist guides the wire through the coronary artery to the site of the stenosis or blockage. The tip of the wire is then passed across the blockage. The cardiologist controls the movement and direction of the guide wire by gently manipulating the end that sits outside the patient through twisting of the guide wire
• While the guide wire is in place, it now acts as the pathway to the stenosis. The tip of the angioplasty or balloon catheter is hollow and is then inserted at the back of the guide wire--thus the guide wire is now inside of the angioplasty catheter. The angioplasty catheter is gently pushed forward, until the deflated balloon is inside of the blockage. The balloon is then inflated, and it compresses the atheromatous plaque and stretches the artery wall to expand.
• If an expandable wire mesh tube (stent) was on the balloon, then the stent will be implanted (left behind) to support the new stretched open position of the artery from the inside.

Coronary stenting

Traditional ("bare metal") coronary stents provide a mechanical framework that holds the artery wall open, preventing stenosis, or narrowing, of coronary arteries. PTCA with stenting has been shown to be superior to angioplasty alone in patient outcome by keeping arteries patent for a longer period of time.

Newer drug-eluting stents (DES) are traditional stents that are coated with drugs, which, when placed in the artery, release certain drugs over time. It has been shown that these types of stents help prevent restenosis of the artery through several different physiological mechanisms, which rely upon the suppression of tissue growth at the stent site and local modulation of the body's inflammatory and immune responses. Three drugs, sirolimus, everolimusand paclitaxel, have been demonstrated safety and efficacy in this application in controlled clinical trials by stent device manufacturers. [citation needed] However, in 2006 three broad European trials seem to indicate that drug-eluting stents may be susceptible to an event known as "late stent thrombosis", where the blood-clotting inside the stent can occur one or more years post-stent. While this event is rare, it is extremely dangerous and is fatal in about one-third of cases when the thrombosis occurs.

Risks

Risks of angioplasty are uncommon, and the procedure is widely practiced. Coronary angioplasty is usually performed by an interventional cardiologist, a medical doctor with special training in the treatment of the heart using invasive catheter-based procedures. [citation needed]

Angioplasty has become considerably safer over the years and is now commonly performed. Although it is associated with some risks these are considerably less than for open-heart bypass surgery with its resulting post-operative pain. However the likelihood of recurrence of angina, and requirement for repeated procedures has been higher with angioplasty. The latest trial (ARTS II) has suggested that PCI with DES may be superior, at least in the short term.

Some chest discomfort occasionally may be experienced and it is for this reason that the patient is awake during minimally invasive angioplasty; the reporting of any symptom allows the cardiologist to take necessary immediate action. Bleeding from the insertion point in the groin is common, in part due to the use of anti-platelet clotting drugs. Some bruising is therefore to be expected, but occasionally a hematoma may form. This may delay hospital discharge as flow from the artery into the hematoma may continue (pseudoaneurysm) which requires repair. Infection at the skin puncture site is rare and dissection (tearing) of the access blood vessel is uncommon. Allergic reaction to the contrast dye used is possible, but has been reduced with the newer agents. Deterioration of kidney function can occur in patients with pre-existing kidney disease, but kidney failure requiring dialysis is rare. Vascular access complications are less common and less serious when the procedure is performed via the radial artery.

In the long term, the most common risk is of the stent restenosis, as discussed above. This has been reduced considerably with the use of newer stents coated with certain medicines (drug-eluting stents). The most serious risk is the rare provocation (3%) of a heart attack during or shortly after the procedure; this may require emergency open cardiac surgery. Angioplasty carried out shortly after a myocardial infarction has a risk of causing a stroke of 1 in 1000, which is less than the 1 in 100 risk encountered by those receiving thrombolytic drug therapy.

The overall risks of death with angioplasty is approximately 1%, but the underlying severity of the heart disease, fitness of the patient and presence of other illness affect each individual’s risk. Hence for those with relatively minor heart disease, preserved good cardiac function, reasonable level of fitness and absence of other illnesses, the risk will be considerably less.

When failures of PTCA occur, they are often treated using coronary artery bypass grafting (CABG).

Peripheral angioplasty

Peripheral angioplasty refers to the use of mechanical widening in opening blood vessels other than the coronary arteries. It is often called percutaneous transluminal angioplasty or PTA for short. PTA is most commonly done to treat narrowings in the leg arteries, especially the common iliac, external iliac, superficial femoral and popliteal arteries. PTA can also be done to treat narrowings in veins. Renal artery angioplasty

Atherosclerotic obstruction of the renal artery can be treated with angioplasty of the renal artery (percutaneous transluminal renal angioplasty, PTRA).Renal artery stenosis can lead to hypertension and loss of renal function.

Carotid angioplasty

Generally, carotid artery stenosis is treated with angioplasty and stenting for high risk patients in many hospitals. It has changed since the FDA has approved the first carotid stent system (Cordis) in July 2004 and the second (Guidant) in August 2004. The system comprises a stent along with an embolic capture device designed to reduce or trap emboli and clot debris. Angioplasty and stenting is increasingly being used to also treat carotid stenosis, with success rates similar to carotid endarterectomy surgery. Simple angioplasty without stenting is falling out of favor in this vascular bed. SAPPHIRE, a large trial comparing carotid endarterectomy and carotid stenting with the Cordis stent found stenting non-inferior to carotid endarterectomy

Stent

In medicine, a stent is either an expandable wire form or perforated tube (conventionally perforated by means of laser cutting) that is inserted into a natural conduit of the body to prevent or counteract a disease-induced localized flow constriction

Applications

The main purpose of a stent is to counteract significant decreases in vessel or duct diameter. Stents are often used to alleviate diminished blood flow to organs beyond an obstruction in order to maintain an adequate delivery of oxygen. Although the most common use of stents is in coronary arteries, they are widely used in other tubular structures, such as central and peripheral arteries and veins, bile ducts, esophagus, colon, trachea or large bronchi, ureters, and urethra.

Problems

One of the drawbacks of vascular stents is the potential development of a thick smooth muscle tissue inside the lumen, the so-called neointima. Development of a neointima is variable but can at times be so severe as to re-occlude the vessel lumen (restenosis), especially in the case of smaller diameter vessels, which often results in reintervention. Consequently, current research focuses on the reduction of neointima after stent placement. Considerable improvements have been made, including the use of more bio-compatible materials, anti-inflammatory drug-eluting stents, resorbable stents, and others. Fortunately, even if stents are eventually covered by neointima, the minimally invasive nature of their deployment makes reintervention possible and usually straightforward.

Etymology

The origin of the word stent remains unsettled. The verb stenting was used for centuries for the process of stiffening garments (a usage long obsolete, per the OED) and some believe this to be the origin. Others attribute the noun stent to Jan F. Esser, a Dutch plastic surgeon who in 1916 used the word to describe a dental impression compound invented in 1856 by the English dentist Charles Stent (1807–1885), which Esser employed to craft a form for facial reconstruction. The full account is described in the Journal of the History of Dentistry. According to the author, from the use of Stent's compound as support for facial tissues grew the eventual use of stent to open various bodily structures. Worth noting though is that the "stents" used in medical pratice were invented by the swedish engineer Hans Wallstén. They were initially called "Wallstents" but are now usually called stents.

Therapy: Stent implantation versus Coronary bypass surgery

Coronary heart disease (CHD) is a major cause of morbidity and mortality throughout the world, and both surgical revascularisation (coronary artery bypass grafting, CABG) and percutaneous coronary intervention (PCI) are established treatment options. The rapid developments in both surgical and percutaneous techniques have been such that the choice of the optimum revascularisation strategy is changing, often without an established evidence base; this is particularly true in complex conditions including patients with three-vessel and left main stem anatomy. The widespread use of drug eluting stents has resulted in a significant reduction in patients referred for CABG although published data favours the surgical approach in this high-risk group.

The SYNTAX Trial aims to explore the interface between treatment with CABG and PCI in patients with three-vessel and left main stem disease, comparing CABG using contemporary techniques and PCI using drug eluting TAXUS stents. The aim of the trial is to establish non-inferiority of PCI with CABG. The unique feature of the SYNTAX trial is the ‘all comers’ strategy. A team comprising a cardiac surgeon and an interventional cardiologist assesses each patient; if equivalent revascularisation is applicable using both techniques, the patient is accepted for randomization; if either CABG or PCI is deemed unsuitable for technical reasons or the presence of co-morbidities, then the patient is recruited into one of two parallel registries which will track these patients undergoing either CABG or PCI. The patient will not be included in the randomized cohort. 1800 patients will be randomized (1:1) between CABG and PCI. The primary end-point is a major adverse, cardiac and cerbrovascular event at one year. All patients will be followed for five years. Of the 1800 patients, 710 with left main stem disease will be randomized between CABG and PCI. In this sub-group, repeat cardiac catheterisation will be undertaken after the one-year primary endpoint to determine graft and native vessel patency (the Le Mans sub-study).

The SYNTAX Trial is one of the most important trials ever undertaken in the field of coronary revascularisation and will provide a rational basis for choosing the optimum revascularisation strategy in patients for many years to come.

Types of Stent

Vascular

• Bare Metal Stent
• Covered Stent and Stent Graft
• Drug-eluting stent

Other

• Urinary Tract Stent
• CHD Stent
• Rectal Stent
• Oesophageal Stent