Coronary Bypass Procedures

Surgery for Coronary Artery Disease

Background

The coronary arteries provide blood flow to the heart muscle to be able to pump blood to the whole body and organs. The three main arteries are embedded in the heart muscle of fatty surface of the heart and branch off into numerous smaller blood vessels. When an artery develops a blockage or obstructive plaque as in the picture below, the decreased blood flow in the different territories (ischemia) produces chest pain and eventually a partial or complete heart attack depending on the severity of the blockage.

Symptoms of coronary blockage and flow insufficiency include chest pressure or pain, left arm discomfort, shortness of breath or indigestion. For women, symptoms can be more subtle, such as bloating, upper abdominal pain, fatigue or indigestions. In diabetics, pain may not be present but shortness of breath is usually more common.

When blockages are distinct and isolated, stents (PCI) are usually the first line therapy. Although easier to place and with low risk, the risk of recurrent heart attacks and re-intervention is very common. They are placed using guidelines of treatment and require the use of antiplatelet blood thinners to prevent early closure.

Coronary artery bypass grafting (CABG) is the best choice in patients with more extensive disease, complex anatomy that precludes stenting, 3 vessel coronary involvement and diabetics. The surgeon reroutes blood flow by placing a vein or artery distal to the blockage providing normal flow to the heart muscle of each specific territory. Although the early risk of surgery is higher than PCI, after one year, the risk of intervention and graft closure favors the CABG, with a lower re-intervention rate, heart attacks and prolonged survival and heart unction preservation (Syntax trial).

At Baptist Cardiac Surgery we perform over 600 CABGs either isolated or associated with other procedures. Our surgeons have an operative mortality way below of the national average (< 1 %) and a low complication rate. The average stay in the hospital is 5 days and most patients resume normal activity within 3-4 weeks. Our blood transfusion rate is less than half of the national average. Our program has been awarded the 3 star ranking (only < 10 % of hospitals nationwide) by the STS (Society of Thoracic surgeons), the best in the state.

Standard CABG

Once the operation is indicated, a complete preoperative work up is conducted to rule out other cardiac problems (i.e. valve leaks, atrial arrhythmias, etc.), lung disease, kidney problems, diabetic control and blood typing.

The patient either as an inpatient or electively from home is wheeled to our cardiovascular operating rooms and put to sleep by an anesthesiologist specialized in cardiac patients. The traditional exposure of the heart is through the splitting of the sternal bone (sternotomy). The cardiac structures are identified and then plastic cannulas are placed in the aorta and right atrium to divert flow to the heart lung-machine that will allow temporary hemodynamic support and allow the surgeon to stop the heart to perform the operation while the machine maintain oxygenated flow to the rest of the body and vital organs. A clamp is placed in the proximal aorta to isolate the heart and a K+ (potassium) solution in instilled in the heart to stop it and protect it while the surgeon promptly makes the connections in the blocked coronary vessels. For most CABG operations, the surgeon uses the left internal mammary artery (LIMA) that is connected proximally to the aorta and usually placed to the LAD (left anterior descending) artery and is clinically proven to remain open for longer time than the vein (> 20 years in most patients). The surgeon will also use vein harvested from the leg using less invasive techniques with a scope and 2 small incisions.

With the heart flaccid and stopped, the surgeon attaches (sutures) the distal portion of the LIMA and vein grafts distal in the artery to the blockages using fine suture (hair diameter). The veins are positioned around the heart and then the proximal ends and sutured to the proximal aorta with fine suture material as well. Once the graft connections are completed, the aortic clamp is removed from the aorta and then the heart is allowed to beat and gradually resume normal function. The gradually weaned from the heart lung machine and then the cannulas removed and the blood thinning reversed with medications. The chest is closed with wires and draining tubes are left for 1-2 days.

Classic 3 vessel CABG with LIMA and 2 vein grafts
Heart lung machine
Endoscopic vein harvest (EVH)

Off pump CABG (OPCAB)

When the bypass operation is performed without the heart-lung machine, the operation is conducted with the heart beating instead of the heart on standstill. Each vessel is isolated individually with fine vessel loops and the ara is stabilized with a foot device to allow the surgeon to perform the connection with minimal motion. Once the vessel is completed, then the next one is connected with different techniques to inmobilize the vessels in the inferior and lateral wall. At the end, the proximal connections are completed. OPOCAB is a more demanding procedure that only benefit patient if performed by surgeons with experience and proven outcomes withthis technique. This technique benefits patients with very poor lung function, renalk failure, calcific aorta and patients that are not willing to receive blood such as Jehova’s witness population. Patients with 1-2 vessel CAD and young age also are good candidates.

Retractor for off pump surgery with stabilization of the anterior
Stabilization of coronary target and anastomosis construction

MICS-CABG

MICS stands for minimally invasive cardiac surgery. This CABG is performed avoiding a sternotomy and by performing a small left lateral incision between the ribs. It is a good operation for a few selected patients that have blockages in the arteries in the front of the heart, such as LAD and diagonal. It is a procedure most of the times done off pump and stabilizing the territory with OPCAB devices and instruments. It is a very demanding procedure that requires significant surgeon expertise. The benefit of this procedure is avoidance of the sternotomy and decreasing the chances of infection, less pain postoperatively and excellent cosmetic result. We do this procedure in selected patients only.

6cm left mini-thoracotomy with exposure of LAD coronary artery.
Closed incision left chest

Multiple arterial revascularization

It has been clinically proven since 1996 that the use of the left internal mammary (LIMA) to the left anterior descending artery (LAD) has a protective effect when performing a CABG and also a long term effect on survival and patency rate of the graft with a tremendous clinical benefit. Therefore, the use of the LIMA is mandatory in any isolated CABG operation. Less clear has been the short and long term effect of the use of the right IMA (RIMA) and other arterial grafts such as the radial artery and the gastroepiploic grafts. Recent data has shown a beneficial effect of its use, especially the RIMA use in younger patients and with very stenotic coronary targets. Our team uses routinely bilateral IMAs in patients deemed to benefit from these approach, usually younger, non-diabetic patients with adequate coronary targets.

Re-operative coronary bypass surgery

CABG operations have been performed for the last 50 years or more. The need of re-intervention in the CABG grafts is very common, frequently with stent in isolated grafts a redo CABG when the recurrence of blockages is more extensive. The chance of need of CABG at 10 years or more is greater than 20 %. These operations have a higher risk for mortality and complications and required experienced surgeons with high volume of cases. Multiple techniques are used and alternative conduits to vein are often required.

Our team is known for its expertise in performing complex coronary surgery reoperations with a statewide referral pattern.