The Amazing New technic in Heart Bypass

(Since the news about OPCAB was published in Cebu Daily News and in some national dailies last week, we have received a lot of inquiries about this exciting new and revolutionary heart operation. Following are the answers to some of the questions sent to us.---PSC)

What is OPCAB?

OPCAB stands for Off-Pump Coronary Artery Bypass, which means the heart bypass surgery is done without the use of the heart lung machine and done on a beating heart. This is a cutting-edge surgical technology different from the conventional coronary bypass, and is, without any doubt, a trend for the new millenium.

What is the conventional technic?

The way coronary bypass surgery has been performed since it was first popularized by Rene Favoloro, M.D, an Argentinian cardiac surgery fellow at the Cleveland Clinic, in 1967, is to arrest (stop) the heart completely during the actual coronary bypass, with the patient hooked up to a heart-lung machine, which supports the patient during surgery. After the grafts are connected, the heart re-starts beating on its own or is electrically defibrillated (shocked to re-start the heart).

Why is a heart-lung machine needed in this situation?

When the heart has to be stopped in order for the surgeon to be able suture and connect the bypass grafts to the tiny (1.5 mm diameter) coronary arteries beyond the blocked segment, the patient's circulation would obviously be halted. Therefore, to provide and maintain uninterrupted blood circulation, the heart-lung machine, to which the patient is connected at the start of the operation, is on turned. This temporarily acts as the substitute heart and lung for the patient during the surgery to maintain life. The blood of the patient is drained in a continuous circuit to the heart-lung machine, gets oxygenated by the "Membrane Oxygenator" (the lung counterpart in the machine) and pumped back to the patient.

Page Two OPCAB Are there possible complications of stopping the heart?

Arresting the heart during surgery and clamping the aorta (in order to maintain a clear and bloodless surgical field to make it easier for the surgeon to do the bypass) totally cuts off the circulation from the aorta to the coronary arteries (which brings blood containing oxygen and nutrition to the heart muscles). Clamping the aorta therefore deprives the heart muscles of blood, which could cause a heart attack right there and there. In order to minimize the chance of a heart attack during surgery, the demand for oxygen and nutrition is reduced by cooling down the body temperature to 28 degrees Centigrade and the heart immersed in ice-cold (4 degrees C) salt solution. High doses of Potassium Chloride is given to help arrest the heart in diastole (relaxed state) and lull it into a safe and temporary "hibernation." This in effect will reduce the need for oxygen and nutrition of the heart muscles while the aorta is clamped (which, as stated earlier, cuts off the blood oxygen and nutrition supply to the heart muscles). These time-tested and sophisticated medical maneuvers are done to prevent heart muscle damage that could lead to a heart attack. This method is safe but has possible complications.

Are there any risks in using the heart-lung machine?

Yes. While the heart-lung machine is a safe device tested and used the past forty plus years around the world, and improved the past ten years, there are still some possible complications attendant to its use. Some of the more common ones include destruction of the blood components and coagulation factors, lowering of the immune system, possible air or blood clots, mild and temporary memory impairment, severe fatigue and weakness after surgery, and possible stroke. This is the reason why OPCAB technic (on a beating heart and without using the heart-lung machine) has been introduced and starting to be popular, especially in the United States and Europe. About 7% of coronary bypass in the United States is now done the OPCAB way.

How can surgery be done on a beating heart?

Performing heart bypass surgery on a beating heart is like sewing (connecting) two tiny spaghetti-size pipes (1.5 to 2 mm in diameter each) while they shake or wiggle 80 or more times a minute, hitting a moving target, so to speak. The motion of the heart is minimized with the use of the OPCAB instruments, stabilizers, and a special surgical maneuver and positioning done by the OPCAB-trained surgeon. While this method is technically more difficult for the surgeon, it is a lot more advantageous for the patient, who will need less blood transfusion, if any at all, feel less fatigued after surgery, and may even go home within 3 to 5 days after the bypass. But the greatest medical advantage is in totally eliminating the potential complications of using the heart-lung machine and of arresting the heart.

Page Three OPCAB Is every bypass patient eligible for the OPCAB system?

No. Not all patients who need coronary bypass surgery are candidates for the OPCAB procedure. Working on the arteries on the front surface or the left or right sides of the heart is obviously easier than doing surgery on the back of the heart, with the tip of the heart lifted up, twisting the heart about 90 degrees. This position sometimes kinks the major veins and arteries connected to the superior part of the heart and this could cause heart irregularities, a fall in the blood pressure and a fall in oxygen saturation. The surgeon has a pre-conditioning test he uses to determine if the patient can tolerate beating heart surgery using the OPCAB technic. Since most of the patients undergoing heart bypass also have blockages in the arteries at the back of the heart, which will also need bypass grafts, the procedure becomes more technically challenging and more surgically exacting that not every heart surgeon is trained or is capable of performing this minimally invasive OPCAB technique.

Is OPCAB done by many surgeons in the United States?

About 10% of cardiac surgeons in the United States perform this minimally invasive coronary artery bypass procedure. Special additional hands-on training on the OPCAB system is required for heart surgeons to undergo before they are allowed to use this revolutionary technic. The extra training needed, the more exacting technical skills required, the psychological barrier of not using the heart-lung machine to which heart surgeons have been comfortable using, and other logistical factors is the reason why majority still do not do OPCAB. But the trend towards this minimally invasive procedure is growing.

How many bypass grafts can be done using the OPCAB method?

As many grafts implanted (3 to 5 or 6) through the conventional technic may be created using OPCAB. It is our understanding that the quadruple coronary bypass performed on June 8, 1999 at the Cebu Cardiovascular Center of the Cebu Doctors' Hospital on Mr. Harold Vernon Henry, a 68-year-old American retiree in Cebu, is the first such OPCAB procedure done in the Philippines with that many (four) bypasses, including a graft to the back of the heart.

Is the OPCAB more expensive than the conventional bypass?

Everything considered (non-use of the heart-lung machine, lesser consumable supplies, shorter length of hospital stay, less need for blood and platelet transfusions), OPCAB has turned out to be less expensive in most instances. However, the final cost will depend on how severe the disease is and on other complicating conditions, such as diabetes, hypertension, obesity, smoker's lung disease, which can influence the speed of recovery of the patient. The cost will therefore vary on a case to case basis. However, in general, the total cost of heart

Page Four OPCAB

bypass surgery package in Cebu is a lot less expensive than in Manila, (and obviously much much less than in the United States), not even considering the inconvenience and the additional cost of airfares, board and lodging and land transportation involved in an out-of-town surgery.

©2003Raoul R. Diez, M.A.O.D.