Farhan, a thirty five year old banker, underwent bypass surgery three years ago. He is back to work, working full time and enjoying his game of golf every evening. He flies abroad to attend meetings and makes full contribution to his job. He is only taking a couple of tablets and observes a few restrictions in his diet. For all practical purposes, he is leading a very active and productive life. And so are most people at different ages, employed in different jobs, from both sexes who had bypass surgery!
Bypass surgery is the most commonly performed heart surgery for coronary artery disease. Persons who develop blockages in their tubes that supply the heart called coronary arteries are the candidates for such surgery. More than 300,000 people have successful by pass surgery only in the United States each year. Bypass surgery is now being routinely performed in major centres of Pakistan with acceptable morbidity and mortality.
What is bypass operation?
Arteries supplying heart, called coronary arteries, develop blockages and can become clogged. Bypass surgery improves blood flow to heart employing a new route, or by “bypassing” blockages in the clogged or diseased artery. The surgery involves using a part of vein from leg or an artery from chest or another part of body to bypass the blocked part of the diseased coronary artery. This creates a new route for blood to flow, so that the heart muscle gets uninterrupted oxygen-rich blood.
How is bypass operation performed?
During bypass surgery, the breast bone (sternum) is divided, heart is stopped, and blood is circulated through a heart-lung machine which performs the function of heart and lungs. Unlike other forms of heart surgery, the chambers of heart are not opened during the operation. Heartlung machine takes over circulation and given enough time to operation on a stand still heart which makes surgery like this possible. The use of machine allows the surgeon to stop heart while the vital organs continue to receive blood and oxygen. Meticulous surgery can be done without interference from bleeding or heart’s pumping motion. Used successfully for the first time in 1953, the machine has proved to be a revolutionary piece of equipment. A perfusion technologist operates the machine. Before hooking upto this machine, a blood-thinning medicine called an anticoagulant is given to prevent blood from clotting. Two large sized cannulas are put in and sewn in major vessels which carry the blood back from inferior and superior vena cava. This blood is oxygenated by the machine like lungs as blood passes in close vicinity of controlled oxygen. A mortorized system then drives this blood back to body where it is delivered to aorta through a cannula to be further distributed to all over body. Meticulous control of speed of motors is required, drawing blood out of body and then delivering back. The amount of oxygen and anticoagulation has to be managed carefully.
The surgical team is led by a cardiovascular surgeon and includes other assisting surgeons, an anesthesiologist, and surgical nurses. A long piece of vein from leg (the saphenous vein) is removed. This piece of vein is called a graft. One end of the graft is attached to ascending aorta, the large artery that carries oxygen-rich blood out of the heart to the body. Other end of the graft is attached to coronary artery below the blockage. The surgeon may choose to use an artery from the inside of chest wall (the internal mammary artery) instead. Or the surgeon may use both vein and artery. The procedure can take from 1 to 2 hours, depending on the number of bypasses needed. The stay in the hospital is about a week, including at least 1 to 3 days in the Intensive Care Unit (ICE). It may prolong in case of any complications. Usually the patient is up and about after two to three days and is encouraged to walk liberally after that.
Advances in bypass surgery:
There have been continuous attempts to make bypass surgery lesser invasive and more patient friendly. Minimally invasive coronary artery bypass surgery has been a major advance. It is done through smaller incisions. It may involve using the mammary artery as a graft. Saphenous veins may also be used. The procedure may be done without stopping heart. Some patients can leave the hospital within 48 hours. This operation is only used for patients whose blockages can be bypassed through this smaller incision and whose risk of complications is low.
Off pump surgery has been heralded as a major step forward to improve post operative course and complications besides reducing the cost. Like conventional bypass surgery, off-pump coronary artery bypass surgery (OPCAB) bypasses blockages in coronary arteries. Off-pump bypass involves the same two procedures that are performed during traditional bypass surgery. In the first, the surgeon removes (harvests) one of the patient’s blood vessels – usually either saphenous vein in leg or mammary artery. In the second procedure, the surgeon uses the blood vessel to create a detour (bypass graft) around the blockages in coronary arteries.
Off-pump bypass allows the surgeon to sew the bypass grafts into place in the chest without stopping heart. This eliminates all risks associated with stopping heart that is necessary during traditional bypass surgery. It also reduces the risk that a patient may experience depression and/or mood swings following surgery – a common side effect with traditional bypass surgery. The surgeon uses certain heart stabilizers and positioners to keep the targeted region of heart virtually motionless while working on a particular coronary artery. The stabilizers restrict heart’s motion to create a stable and nearly still work area for the surgeon. Heart maintains its own rhythm throughout the procedure. In addition, bleeding is greatly reduced, so patients are less likely to need blood transfusion.
What does life promise after bypass?
A person can go back to normal life and job in four to six weeks following an uncomplicated surgery. It may take longer in older age group, those with poor heart function and those with coexistent serious medical problems. One can usually go back to work in 4 to 6 weeks for an office job. Those who have more physically demanding jobs may need to wait longer. In some extreme cases, one may need to find a job that is not as physically demanding. Twenty percent or less of bypass patients may need a second procedure like angioplasty or repeat bypass after 10 years.
Does bypass mean an end to walking and abstinence from cholesterol rich diet?
Is bypass surgery a panacea? Does it give a license to eat and drink as one pleases? Two things are of vital importance after bypass operation: first, meticulous control of risk factors and second, regular exercise. After bypass surgery, the diet has to be modified and one has to limit fat and cholesterol. Risk factors have to be regularly watched and scrupulously controlled. Exercises like walking and swimming are recommended, to get the strength back and develop stamina. The role of exercise has been discussed in details in controlling various risk factors. A cardiac rehabilitation program may be joined on doctor’s recommendation. These programs can help to make lifestyle changes like starting a new diet and exercise program, quitting smoking, and learning to deal with stress.
To conclude, bypass surgery has been a landmark in our fight against coronary artery disease. This is an exquisite application of common sense employing body’s own vessels as alternate paths to deliver blood to viatal parts of heart. The operation has seen many advances and is being done as a routine in many centres. The operative mortality is very acceptable and most patients are back to work in four weeks and most can go back to the previous level of activity.
Heart Transplant - Is it a Viable Option?
“Heart transplants have been successfully performed since 1967. Latest figures tell us that 85 percent of those who receive heart transplants survive for more than one year, and 70 percent live five years following the procedure,” I told John Plant, a 40 years old bank with a dilated and poorly pumping heart. He had been in and out of the hospital many times in the last six months. He was on maximal treatment but his effort tolerance remained severely impaired. We had proposed ‘heart transplant’ to him and his first knee jerk reaction was a big ‘no’. “A dream has been transformed into a reality and many patients are enjoying nearly normal life after heart transplant. Today’s heart transplant recipients live longer after surgery than those who received heart transplants just 10 years ago. Many transplant patients go back to work and many participate in moderately strenuous activities, such as walking, swimming and even running,” I added to convince him and eventually he agreed to go for it. Two years down the lane, he was active, playing golf and enjoying holidays in Paris.
Heart transplant has emerged as an established safe and effective theraphy for patients with severe heart problems. Technique of heart transplantation has made great strides of development over the years. Indeed it is a major surgery, in which a severely diseased or damaged heart is replaced with a healthy heart from a recently deceased person. Mortality during surgery is acceptable and the biggest problems are find a heart and prevention of rejection. Patients continue to face a lengthy waiting list to receive a donor heart. According to the recent figures approximately 3,800 patients were waiting for a heart transplant as of June 2007. Only 2,148 people received a donated heart in 2007. According to the American Heart Association, at the present time all over the world, the majority of heart transplant patients were while males. More than half are between the ages of 50 and 64, and about 20 percent are between the ages of 35 and 49. Researches are working to develop equipment to improve the health and comfort for patients waiting for a donor heart and, ideally, to develop a mechanical heart that could permanently solve the shortage problem.
Who needs heart transplant?
When a patient is diagnosed as having an end-stage heart disease, and all medical interventions have failed, and the patient is stable enough to sustain a major surgery then he or she is considered for transplant. End stage heart disease due to decrease in blood supply – coronary artery disease and disease of heart muscle called cardiomyopathy are the most common conditions that may lead to a heart transplant. Heart diseases due to inborn heart problems which are not amenable to surgery are the most common reasons for heart transplant in children. Patients with failure of a previous bypass and persistent angina and heart failure are considered for heart transplant.
Heart transplants are sometimes performed along with lung transplants for individuals with end-stage lung disease that also involves the heart. These conditions are elevated pressures in right sided circulation called pulmonary hypertension. High blood pressure in blood vessels of lungs arising from right side of heart is consequent to either primary – where the cause is not known or Eisenmenger syndrome where the cause is a congenital heart disease. The condition accounts for nearly half of all heart-lung transplants.
Who donates the heart?
Unlike most organs, the heart can only be obtained from donors who die a “brain death,” meaning that the brain dies while the body remains on life support. Organs are obtained from people who give their consent to have certain organs donated. They can also be obtained by permission of next of kin when a suitable donor is considered to be “brain dead.” Although almost 40 percent of donated kidneys are surgically removed from living donors, most major organ donations (e.g., the heart, lungs and liver) are pledged while living and removed when the donor dies. Because of the great demand for organ donors, generally healthy people are strongly encouraged to become donors.
How the heart is transplanted?
Patients waiting for a donor heart are required to report to the hospital immediately on finding a donor. If the donor heart is in the same hospital as the recipient, then the surgery is performed as soon as all preparations have been made. If the donor heart is being transported by ambulance or by air, then the surgical team responsible for the transfer keeps the hospital team informed of their progress.
When the time is right, the patient is given general anesthesia. An incision is made through the chest and sternum, and the ribs are separated. A heart-lung machine takes over the functions of heart and lungs, freeing heart from its normal function so that it can be removed. Some heart muscle is reserved during extraction to act as a support for the new heart as it is sewn into place. When the new heart is positioned and blood vessels are reattached, a heart incision is closed, heart is restarted and blood circulation and oxygen are stored. The warmth of blood should “wake up” the heart and stimulate it to start beating. If this does not occur, it may be necessary to start the heart using an electric shock (defibrillation). Once blood is flowing through the new heart normally and without any leaks, the heart-lung machine is disconnected and chest incision is closed.
After the heart transplant, patient is kept in ICU and monitored during this critical time by cardiac surgeon, cardiologist and other members of the hospital staff. They watch closely for any signs of heart rejection or infection. Medications that suppress the body’s natural immune system are administered to counter the body’s tendency to reject the new heart, and these medications have dramatically reduced the number of rejections.
Patients are unlikely to be very active in the next couple of days, but should be able to walk around in just three or four days. The total length of a hospital stay after a heart transplant is 10 to 14 days. Once a patient is discharged from the hospital, cardiologist and primary physician provide regular medical support, including biopsies and other diagnostic tests several times a year.
The improved life expectancy of patients after a heart transplant is largely due to a new drug called cyclosporine. It is an immunosuppressive drug that appeared in 1983. From its unique way of suppressing the immune system, cyclosporine has become a mainstay in minimizing the body’s tendency to reject a new heart. This is a major risk associated with transplant surgery. When rejection occurs, the immune system sends out antibodies to destroy the new heart, which is perceived as foreign or ‘invading’ tissue cells. Left unchecked, this rejection can result in extensive damage and failure of the transplanted heart.
Problems after the transplant:
Three main problems associated with transplant are rejection, infection and accelerated atherosclerosis.
a. Rejection: Certain tests are required on a regular basis to predict whether the heart is being rejected. These tests include regular biopsies and serial blood tests. Serial biopsies are done to monitor body’s response to the transplanted heart. This involves using a thin tube to remove a small piece of heart tissue. The tube is inserted through a vein either in the groin or side of the neck. Biopsies are outpatient procedures that can be done in under an hour. They are performed often in the first four months after transplantation and, less frequently, in months and years after that. The risk of transplant failure is three times greater among recipients with high levels of troponin I than those with normal levels of this enzyme.
Patients can monitor themselves, as some symptoms may signal rejection, including dizziness, nausea or vomiting, chest pain, shortness of breath, flu-like symptoms like chills, sore throat and fever. Rejection, however, is not necessarily an irreversible event. It can be controlled with different dosage regimen or timing of medications. Patients are encouraged to immediately contact their transplant centre or team, should any of the above symptoms occur.
b. Infection. Patients are urged to immediately report to their physician if any of the following signs of infection like fever, redness, swelling and drainage of fluid appear.
c. Accelerated atherosclerosis. When patients receive a new heart, they also receive new coronary arteries on the surface of that heart. Although these new coronary arteries may have less blockages than their original coronary arteries, heart transplant recipients are more like to develop coronary artery disease (CAD). This disease is thought to be part of the slow rejection process in the transplanted hearts. About 50 percent of heart transplant patients develop CAD. Therefore, patients must undergo cardiac tests periodically to check for the disease.
A longer-term goal for some researchers is the genetically engineered heart. The organ is composed of human tissues – perhaps one’s own – and is cultured or grown over a period of months to match detailed specifications. Currently, this “heart-in-a-box” project exists only in a university research facility, but researchers have a goal to have cryogenically (defined as ‘low-temperature”; in this case, very cold) stored organs available for transplant in less than a decade.
The dreams of yesterday have worn the attire of reality today. Heart transplant is a viable option in selected patients with heart failure, who do not respond to maximal therapy. Due to recent technological advances, the outlook has improved, survival being more than 83% at one year.
Balloons and Heart
The entry of balloons has heralded a new era in the world of medicine with profound effects in its various important fields. The strongest ripples were however felt in cardiology and specialties dealing with gastroenterology, anaesthesia and urinary system. In cardiology it has revolutionized the approach to many commonly encountered problems. Many more fields await the application of this exciting ‘balloon technology’!
What can balloon do for us? It has been used to track into blood carrying tube – vessels, as air is lighter than blood, so this travels along the course of the vessels. It has been used for retention of a tube in a cavity, with balloon inflated on an end of tube after the entry has been secured prevents its slippage. Similarly it has been used to retain the urinary catheter in the bladder by inflating the balloon at the end. Tubes used in anaesthesia used to have leaking of air around it, that problem is solved by inflating balloon around it. Balloons have been used to arrest bleeding in patients with bleeding varices in dire emergency by exerting direct pressure on bleeding varices.
The biggest breakthrough came with the realization that these balloon could be employed to ‘blow up’ blockages in various parts of body. Balloons of different sizes and quality mounted on different structures have been successfully used for this purpose. They have been used to open up obstructions in gastrointestinal tract without surgery. Blockages in urinary system have been dilated by balloons with minimal patient discomfort and without surgery.
The epic of balloon technology can be witnessed in cardiology where the whole scenario has changed in cardiac catheterization laboratory. Initially cardiac catheterization laboratory was used truly as a laboratory where different diseases were diagnosed based on the information gleaned from catheterization. Now the emphasis is shifting from diagnosis to therapeutics. With the advent of echocardiography, most diseases can be accurately diagnosed without cardiac catheterization. In cardiac cath lab, catheter based therapeutics is predominantly dependent on “poor old balloon”, small balloons blowing up obstruction in coronary and other vessels with excellent results and large balloons opening up narrowed valves with enviable results obviating the need for surgery.
Valvuloplasty:
Large balloons ranging from 10 to 30 mm in diameter are used to open up different valves. Obviously, size of balloon depends on the target and size of patient. These valves are either congenitally narrow or narrow down in later life due to various disease process. Previously surgery was required to open up the stenosed valves and remove the impediments in blood flow. Not any more! The procedure is performed without anaesthesia. As an initial step baseline data is recorded, then access beyond the narrowed valve is secured by manipulating a flexible catheter across it. A long wire is left across the valve and a narrow balloon mounted catheter is manipulated on the wire across the narrowed valve. Once satisfied with the position, the balloon is inflated, first a waist appears confirming the impinging valve on balloon and then it slowly gives way. The The valve is open! No ugly scar on chest, no confinement to bed for days, no need for prolonged antibiotics, no loss of work and the beauty is that the patient can actually walk home the next day.
Obviously these balloon mounted catheters are made of very sophisticated material and a lot of research has been done to perfect the technique and hardware. The catheter system to open Mitral valve is named after Inoue. The only way to cut down the costs are to reuse the balloon after proper sterilization. The chances of success are more than ninety five percent and complication rate is quite low. The balloon used for Pulmonic and Aortic valves are different in size and shape.
Angioplasty (PCI)
Balloon have only recently been tamed, to be used in small vessels supplying heart. It started with Andrea Grundzick in 1979, when a blockage in a vessel was opened in a patient. Since then there has been an explosion in the cath lab of angioplasties. In USA, it is called ‘occulo dilating reflex’ which implies that as soon as a cardiologist sees an obstruction in a vessel, he has an irrepressible urge to dilate it. Or, according to our not very good friends, cardiologists on seeing a blockage develop severe stomach ache which can only be relived on opening up that lesion. No doubt there has been a mad race in opening of the lesions and technology is witnessing tremendous progress in this field.
Most research taking place in cardiology is focused on small balloons used in vessels supplying heart. The aim is to produce tough balloons which can endure high pressure without deforming, mounted on catheter which should have very small profile so that it can negotiate the bends and cross the blockage, the catheters should have enough strength to be pushed around and cross the lesion. Similar research is taking place in paraphernalia like catheter and guide wire.
How is it done? After identifying the blockage a strategy is devised regarding the approach and hardware to be employed. The procedure is similar to angiography where no anaesthesia is administered. After doing angiography, the lesion is crossed with the help of a very find guide wire. Care is taken to float this wire across the lesion preventing it from going to small branches. It is like going through a large tree to a specific branch which might take a minute or a couple of hours. Once the lesion is crossed balloon mounted catheter is introduced and parked at the lesion. The size of balloon chosen depends on the size of the vessel. Satisfied with the position of catheter, the balloon is inflated under X-ray control. Patient experiences pain when balloon is inflated as blood supply to a part of heart is totally prevented. The balloon is kept inflated for as long as a patient can tolerate, varying from a few seconds to a minute. The appearance of waist and later giving way is apparent on X-ray. The lesion gives way with increase in lumen size.
Balloon are also being used to dilate obstructions in vessels supplying brain, kidneys and extremities. New territories are being ventured into and with the development of proper hardware the need for surgery will be obviated in most cases.
Introduction of balloon technology is a fine example of application of common sense to common problems. Balloons have been used for retention, and opening up blockages. This has proven to be a major advance in medicine and surgery and almost all specialties are benefiting from this simple but very exciting technology.
Beyond Balloons and Springs
“You people have been creating havoc in tiny little coronary arteries of the heart, what are you people up to now?” is a question very commonly asked. “Nothing much, after blowing up balloons in the depths of chest, now we are venturing on new territories. Shaving off plaque has been on the cards for a long time with the help of ‘atherectomy’ devices, we have been putting up strong metal scaffolding ‘Stents’ in certain obstructions and using laser in the vessels either to create holes or increase the lumen size. Radiotherapy is being used to prevent restenosis. The name of the game is to enlarge the lumen size with balloon or some other technology,” I brief the gentlemen inquisitive about new technology and his heart, “the other major advance had been to put tiny ultrasound probe mounted catheter into the vessels hence opening a new window to study the vessel before and after the dilatation.”
Balloons have been used for tracking, retention, prevention of leakage, and opening up of stenosis in vessels, valves or other organs. They have been used to track into blood carrying vessels as air is lighter than blood so this travels along the course of the vessel. Swan Ganz catheters are balloon mounted catheters used for pulmonary artery and left heart pressure measurement and determination of cardiac output. Similar balloon tipped catheters have been used as temporary transvenous pacemaker lead. Balloons have been used for retention of the tube in a cavity with balloon inflated on an end of tube after the entry has been secured to prevent its slippage. Most commonly this technique is employed to retain the urinary catheter in the bladed by inflating the balloon at the end.
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Ref: Heal Thy Heart written by Prof: Dr. Muhammad Hafizullah
Bypass surgery is the most commonly performed heart surgery for coronary artery disease. Persons who develop blockages in their tubes that supply the heart called coronary arteries are the candidates for such surgery. More than 300,000 people have successful by pass surgery only in the United States each year. Bypass surgery is now being routinely performed in major centres of Pakistan with acceptable morbidity and mortality.
What is bypass operation?
Arteries supplying heart, called coronary arteries, develop blockages and can become clogged. Bypass surgery improves blood flow to heart employing a new route, or by “bypassing” blockages in the clogged or diseased artery. The surgery involves using a part of vein from leg or an artery from chest or another part of body to bypass the blocked part of the diseased coronary artery. This creates a new route for blood to flow, so that the heart muscle gets uninterrupted oxygen-rich blood.
How is bypass operation performed?
During bypass surgery, the breast bone (sternum) is divided, heart is stopped, and blood is circulated through a heart-lung machine which performs the function of heart and lungs. Unlike other forms of heart surgery, the chambers of heart are not opened during the operation. Heartlung machine takes over circulation and given enough time to operation on a stand still heart which makes surgery like this possible. The use of machine allows the surgeon to stop heart while the vital organs continue to receive blood and oxygen. Meticulous surgery can be done without interference from bleeding or heart’s pumping motion. Used successfully for the first time in 1953, the machine has proved to be a revolutionary piece of equipment. A perfusion technologist operates the machine. Before hooking upto this machine, a blood-thinning medicine called an anticoagulant is given to prevent blood from clotting. Two large sized cannulas are put in and sewn in major vessels which carry the blood back from inferior and superior vena cava. This blood is oxygenated by the machine like lungs as blood passes in close vicinity of controlled oxygen. A mortorized system then drives this blood back to body where it is delivered to aorta through a cannula to be further distributed to all over body. Meticulous control of speed of motors is required, drawing blood out of body and then delivering back. The amount of oxygen and anticoagulation has to be managed carefully.
The surgical team is led by a cardiovascular surgeon and includes other assisting surgeons, an anesthesiologist, and surgical nurses. A long piece of vein from leg (the saphenous vein) is removed. This piece of vein is called a graft. One end of the graft is attached to ascending aorta, the large artery that carries oxygen-rich blood out of the heart to the body. Other end of the graft is attached to coronary artery below the blockage. The surgeon may choose to use an artery from the inside of chest wall (the internal mammary artery) instead. Or the surgeon may use both vein and artery. The procedure can take from 1 to 2 hours, depending on the number of bypasses needed. The stay in the hospital is about a week, including at least 1 to 3 days in the Intensive Care Unit (ICE). It may prolong in case of any complications. Usually the patient is up and about after two to three days and is encouraged to walk liberally after that.
Advances in bypass surgery:
There have been continuous attempts to make bypass surgery lesser invasive and more patient friendly. Minimally invasive coronary artery bypass surgery has been a major advance. It is done through smaller incisions. It may involve using the mammary artery as a graft. Saphenous veins may also be used. The procedure may be done without stopping heart. Some patients can leave the hospital within 48 hours. This operation is only used for patients whose blockages can be bypassed through this smaller incision and whose risk of complications is low.
Off pump surgery has been heralded as a major step forward to improve post operative course and complications besides reducing the cost. Like conventional bypass surgery, off-pump coronary artery bypass surgery (OPCAB) bypasses blockages in coronary arteries. Off-pump bypass involves the same two procedures that are performed during traditional bypass surgery. In the first, the surgeon removes (harvests) one of the patient’s blood vessels – usually either saphenous vein in leg or mammary artery. In the second procedure, the surgeon uses the blood vessel to create a detour (bypass graft) around the blockages in coronary arteries.
Off-pump bypass allows the surgeon to sew the bypass grafts into place in the chest without stopping heart. This eliminates all risks associated with stopping heart that is necessary during traditional bypass surgery. It also reduces the risk that a patient may experience depression and/or mood swings following surgery – a common side effect with traditional bypass surgery. The surgeon uses certain heart stabilizers and positioners to keep the targeted region of heart virtually motionless while working on a particular coronary artery. The stabilizers restrict heart’s motion to create a stable and nearly still work area for the surgeon. Heart maintains its own rhythm throughout the procedure. In addition, bleeding is greatly reduced, so patients are less likely to need blood transfusion.
What does life promise after bypass?
A person can go back to normal life and job in four to six weeks following an uncomplicated surgery. It may take longer in older age group, those with poor heart function and those with coexistent serious medical problems. One can usually go back to work in 4 to 6 weeks for an office job. Those who have more physically demanding jobs may need to wait longer. In some extreme cases, one may need to find a job that is not as physically demanding. Twenty percent or less of bypass patients may need a second procedure like angioplasty or repeat bypass after 10 years.
Does bypass mean an end to walking and abstinence from cholesterol rich diet?
Is bypass surgery a panacea? Does it give a license to eat and drink as one pleases? Two things are of vital importance after bypass operation: first, meticulous control of risk factors and second, regular exercise. After bypass surgery, the diet has to be modified and one has to limit fat and cholesterol. Risk factors have to be regularly watched and scrupulously controlled. Exercises like walking and swimming are recommended, to get the strength back and develop stamina. The role of exercise has been discussed in details in controlling various risk factors. A cardiac rehabilitation program may be joined on doctor’s recommendation. These programs can help to make lifestyle changes like starting a new diet and exercise program, quitting smoking, and learning to deal with stress.
To conclude, bypass surgery has been a landmark in our fight against coronary artery disease. This is an exquisite application of common sense employing body’s own vessels as alternate paths to deliver blood to viatal parts of heart. The operation has seen many advances and is being done as a routine in many centres. The operative mortality is very acceptable and most patients are back to work in four weeks and most can go back to the previous level of activity.
Heart Transplant - Is it a Viable Option?
“Heart transplants have been successfully performed since 1967. Latest figures tell us that 85 percent of those who receive heart transplants survive for more than one year, and 70 percent live five years following the procedure,” I told John Plant, a 40 years old bank with a dilated and poorly pumping heart. He had been in and out of the hospital many times in the last six months. He was on maximal treatment but his effort tolerance remained severely impaired. We had proposed ‘heart transplant’ to him and his first knee jerk reaction was a big ‘no’. “A dream has been transformed into a reality and many patients are enjoying nearly normal life after heart transplant. Today’s heart transplant recipients live longer after surgery than those who received heart transplants just 10 years ago. Many transplant patients go back to work and many participate in moderately strenuous activities, such as walking, swimming and even running,” I added to convince him and eventually he agreed to go for it. Two years down the lane, he was active, playing golf and enjoying holidays in Paris.
Heart transplant has emerged as an established safe and effective theraphy for patients with severe heart problems. Technique of heart transplantation has made great strides of development over the years. Indeed it is a major surgery, in which a severely diseased or damaged heart is replaced with a healthy heart from a recently deceased person. Mortality during surgery is acceptable and the biggest problems are find a heart and prevention of rejection. Patients continue to face a lengthy waiting list to receive a donor heart. According to the recent figures approximately 3,800 patients were waiting for a heart transplant as of June 2007. Only 2,148 people received a donated heart in 2007. According to the American Heart Association, at the present time all over the world, the majority of heart transplant patients were while males. More than half are between the ages of 50 and 64, and about 20 percent are between the ages of 35 and 49. Researches are working to develop equipment to improve the health and comfort for patients waiting for a donor heart and, ideally, to develop a mechanical heart that could permanently solve the shortage problem.
Who needs heart transplant?
When a patient is diagnosed as having an end-stage heart disease, and all medical interventions have failed, and the patient is stable enough to sustain a major surgery then he or she is considered for transplant. End stage heart disease due to decrease in blood supply – coronary artery disease and disease of heart muscle called cardiomyopathy are the most common conditions that may lead to a heart transplant. Heart diseases due to inborn heart problems which are not amenable to surgery are the most common reasons for heart transplant in children. Patients with failure of a previous bypass and persistent angina and heart failure are considered for heart transplant.
Heart transplants are sometimes performed along with lung transplants for individuals with end-stage lung disease that also involves the heart. These conditions are elevated pressures in right sided circulation called pulmonary hypertension. High blood pressure in blood vessels of lungs arising from right side of heart is consequent to either primary – where the cause is not known or Eisenmenger syndrome where the cause is a congenital heart disease. The condition accounts for nearly half of all heart-lung transplants.
Who donates the heart?
Unlike most organs, the heart can only be obtained from donors who die a “brain death,” meaning that the brain dies while the body remains on life support. Organs are obtained from people who give their consent to have certain organs donated. They can also be obtained by permission of next of kin when a suitable donor is considered to be “brain dead.” Although almost 40 percent of donated kidneys are surgically removed from living donors, most major organ donations (e.g., the heart, lungs and liver) are pledged while living and removed when the donor dies. Because of the great demand for organ donors, generally healthy people are strongly encouraged to become donors.
How the heart is transplanted?
Patients waiting for a donor heart are required to report to the hospital immediately on finding a donor. If the donor heart is in the same hospital as the recipient, then the surgery is performed as soon as all preparations have been made. If the donor heart is being transported by ambulance or by air, then the surgical team responsible for the transfer keeps the hospital team informed of their progress.
When the time is right, the patient is given general anesthesia. An incision is made through the chest and sternum, and the ribs are separated. A heart-lung machine takes over the functions of heart and lungs, freeing heart from its normal function so that it can be removed. Some heart muscle is reserved during extraction to act as a support for the new heart as it is sewn into place. When the new heart is positioned and blood vessels are reattached, a heart incision is closed, heart is restarted and blood circulation and oxygen are stored. The warmth of blood should “wake up” the heart and stimulate it to start beating. If this does not occur, it may be necessary to start the heart using an electric shock (defibrillation). Once blood is flowing through the new heart normally and without any leaks, the heart-lung machine is disconnected and chest incision is closed.
After the heart transplant, patient is kept in ICU and monitored during this critical time by cardiac surgeon, cardiologist and other members of the hospital staff. They watch closely for any signs of heart rejection or infection. Medications that suppress the body’s natural immune system are administered to counter the body’s tendency to reject the new heart, and these medications have dramatically reduced the number of rejections.
Patients are unlikely to be very active in the next couple of days, but should be able to walk around in just three or four days. The total length of a hospital stay after a heart transplant is 10 to 14 days. Once a patient is discharged from the hospital, cardiologist and primary physician provide regular medical support, including biopsies and other diagnostic tests several times a year.
The improved life expectancy of patients after a heart transplant is largely due to a new drug called cyclosporine. It is an immunosuppressive drug that appeared in 1983. From its unique way of suppressing the immune system, cyclosporine has become a mainstay in minimizing the body’s tendency to reject a new heart. This is a major risk associated with transplant surgery. When rejection occurs, the immune system sends out antibodies to destroy the new heart, which is perceived as foreign or ‘invading’ tissue cells. Left unchecked, this rejection can result in extensive damage and failure of the transplanted heart.
Problems after the transplant:
Three main problems associated with transplant are rejection, infection and accelerated atherosclerosis.
a. Rejection: Certain tests are required on a regular basis to predict whether the heart is being rejected. These tests include regular biopsies and serial blood tests. Serial biopsies are done to monitor body’s response to the transplanted heart. This involves using a thin tube to remove a small piece of heart tissue. The tube is inserted through a vein either in the groin or side of the neck. Biopsies are outpatient procedures that can be done in under an hour. They are performed often in the first four months after transplantation and, less frequently, in months and years after that. The risk of transplant failure is three times greater among recipients with high levels of troponin I than those with normal levels of this enzyme.
Patients can monitor themselves, as some symptoms may signal rejection, including dizziness, nausea or vomiting, chest pain, shortness of breath, flu-like symptoms like chills, sore throat and fever. Rejection, however, is not necessarily an irreversible event. It can be controlled with different dosage regimen or timing of medications. Patients are encouraged to immediately contact their transplant centre or team, should any of the above symptoms occur.
b. Infection. Patients are urged to immediately report to their physician if any of the following signs of infection like fever, redness, swelling and drainage of fluid appear.
c. Accelerated atherosclerosis. When patients receive a new heart, they also receive new coronary arteries on the surface of that heart. Although these new coronary arteries may have less blockages than their original coronary arteries, heart transplant recipients are more like to develop coronary artery disease (CAD). This disease is thought to be part of the slow rejection process in the transplanted hearts. About 50 percent of heart transplant patients develop CAD. Therefore, patients must undergo cardiac tests periodically to check for the disease.
A longer-term goal for some researchers is the genetically engineered heart. The organ is composed of human tissues – perhaps one’s own – and is cultured or grown over a period of months to match detailed specifications. Currently, this “heart-in-a-box” project exists only in a university research facility, but researchers have a goal to have cryogenically (defined as ‘low-temperature”; in this case, very cold) stored organs available for transplant in less than a decade.
The dreams of yesterday have worn the attire of reality today. Heart transplant is a viable option in selected patients with heart failure, who do not respond to maximal therapy. Due to recent technological advances, the outlook has improved, survival being more than 83% at one year.
Balloons and Heart
The entry of balloons has heralded a new era in the world of medicine with profound effects in its various important fields. The strongest ripples were however felt in cardiology and specialties dealing with gastroenterology, anaesthesia and urinary system. In cardiology it has revolutionized the approach to many commonly encountered problems. Many more fields await the application of this exciting ‘balloon technology’!
What can balloon do for us? It has been used to track into blood carrying tube – vessels, as air is lighter than blood, so this travels along the course of the vessels. It has been used for retention of a tube in a cavity, with balloon inflated on an end of tube after the entry has been secured prevents its slippage. Similarly it has been used to retain the urinary catheter in the bladder by inflating the balloon at the end. Tubes used in anaesthesia used to have leaking of air around it, that problem is solved by inflating balloon around it. Balloons have been used to arrest bleeding in patients with bleeding varices in dire emergency by exerting direct pressure on bleeding varices.
The biggest breakthrough came with the realization that these balloon could be employed to ‘blow up’ blockages in various parts of body. Balloons of different sizes and quality mounted on different structures have been successfully used for this purpose. They have been used to open up obstructions in gastrointestinal tract without surgery. Blockages in urinary system have been dilated by balloons with minimal patient discomfort and without surgery.
The epic of balloon technology can be witnessed in cardiology where the whole scenario has changed in cardiac catheterization laboratory. Initially cardiac catheterization laboratory was used truly as a laboratory where different diseases were diagnosed based on the information gleaned from catheterization. Now the emphasis is shifting from diagnosis to therapeutics. With the advent of echocardiography, most diseases can be accurately diagnosed without cardiac catheterization. In cardiac cath lab, catheter based therapeutics is predominantly dependent on “poor old balloon”, small balloons blowing up obstruction in coronary and other vessels with excellent results and large balloons opening up narrowed valves with enviable results obviating the need for surgery.
Valvuloplasty:
Large balloons ranging from 10 to 30 mm in diameter are used to open up different valves. Obviously, size of balloon depends on the target and size of patient. These valves are either congenitally narrow or narrow down in later life due to various disease process. Previously surgery was required to open up the stenosed valves and remove the impediments in blood flow. Not any more! The procedure is performed without anaesthesia. As an initial step baseline data is recorded, then access beyond the narrowed valve is secured by manipulating a flexible catheter across it. A long wire is left across the valve and a narrow balloon mounted catheter is manipulated on the wire across the narrowed valve. Once satisfied with the position, the balloon is inflated, first a waist appears confirming the impinging valve on balloon and then it slowly gives way. The The valve is open! No ugly scar on chest, no confinement to bed for days, no need for prolonged antibiotics, no loss of work and the beauty is that the patient can actually walk home the next day.
Obviously these balloon mounted catheters are made of very sophisticated material and a lot of research has been done to perfect the technique and hardware. The catheter system to open Mitral valve is named after Inoue. The only way to cut down the costs are to reuse the balloon after proper sterilization. The chances of success are more than ninety five percent and complication rate is quite low. The balloon used for Pulmonic and Aortic valves are different in size and shape.
Angioplasty (PCI)
Balloon have only recently been tamed, to be used in small vessels supplying heart. It started with Andrea Grundzick in 1979, when a blockage in a vessel was opened in a patient. Since then there has been an explosion in the cath lab of angioplasties. In USA, it is called ‘occulo dilating reflex’ which implies that as soon as a cardiologist sees an obstruction in a vessel, he has an irrepressible urge to dilate it. Or, according to our not very good friends, cardiologists on seeing a blockage develop severe stomach ache which can only be relived on opening up that lesion. No doubt there has been a mad race in opening of the lesions and technology is witnessing tremendous progress in this field.
Most research taking place in cardiology is focused on small balloons used in vessels supplying heart. The aim is to produce tough balloons which can endure high pressure without deforming, mounted on catheter which should have very small profile so that it can negotiate the bends and cross the blockage, the catheters should have enough strength to be pushed around and cross the lesion. Similar research is taking place in paraphernalia like catheter and guide wire.
How is it done? After identifying the blockage a strategy is devised regarding the approach and hardware to be employed. The procedure is similar to angiography where no anaesthesia is administered. After doing angiography, the lesion is crossed with the help of a very find guide wire. Care is taken to float this wire across the lesion preventing it from going to small branches. It is like going through a large tree to a specific branch which might take a minute or a couple of hours. Once the lesion is crossed balloon mounted catheter is introduced and parked at the lesion. The size of balloon chosen depends on the size of the vessel. Satisfied with the position of catheter, the balloon is inflated under X-ray control. Patient experiences pain when balloon is inflated as blood supply to a part of heart is totally prevented. The balloon is kept inflated for as long as a patient can tolerate, varying from a few seconds to a minute. The appearance of waist and later giving way is apparent on X-ray. The lesion gives way with increase in lumen size.
Balloon are also being used to dilate obstructions in vessels supplying brain, kidneys and extremities. New territories are being ventured into and with the development of proper hardware the need for surgery will be obviated in most cases.
Introduction of balloon technology is a fine example of application of common sense to common problems. Balloons have been used for retention, and opening up blockages. This has proven to be a major advance in medicine and surgery and almost all specialties are benefiting from this simple but very exciting technology.
Beyond Balloons and Springs
“You people have been creating havoc in tiny little coronary arteries of the heart, what are you people up to now?” is a question very commonly asked. “Nothing much, after blowing up balloons in the depths of chest, now we are venturing on new territories. Shaving off plaque has been on the cards for a long time with the help of ‘atherectomy’ devices, we have been putting up strong metal scaffolding ‘Stents’ in certain obstructions and using laser in the vessels either to create holes or increase the lumen size. Radiotherapy is being used to prevent restenosis. The name of the game is to enlarge the lumen size with balloon or some other technology,” I brief the gentlemen inquisitive about new technology and his heart, “the other major advance had been to put tiny ultrasound probe mounted catheter into the vessels hence opening a new window to study the vessel before and after the dilatation.”
Balloons have been used for tracking, retention, prevention of leakage, and opening up of stenosis in vessels, valves or other organs. They have been used to track into blood carrying vessels as air is lighter than blood so this travels along the course of the vessel. Swan Ganz catheters are balloon mounted catheters used for pulmonary artery and left heart pressure measurement and determination of cardiac output. Similar balloon tipped catheters have been used as temporary transvenous pacemaker lead. Balloons have been used for retention of the tube in a cavity with balloon inflated on an end of tube after the entry has been secured to prevent its slippage. Most commonly this technique is employed to retain the urinary catheter in the bladed by inflating the balloon at the end.
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Ref: Heal Thy Heart written by Prof: Dr. Muhammad Hafizullah
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