An epicardial approach refers to a surgical technique to access the heart and coronary arteries. It involves going through the chest wall and pericardium (the outer lining of the heart) to reach the surface of the heart. This allows for procedures on the outside of the heart, such as coronary artery bypass grafting (CABG).
When is an epicardial approach used?
The main use of an epicardial approach is for coronary artery bypass surgery. Reasons it may be used include:
- The coronary arteries are not accessible by traditional CABG techniques due to anatomical variations or extensive disease
- Repeat CABG surgery when the bypass grafts from a prior traditional CABG are no longer functional
- Other complex cardiac surgeries like valve repair or replacement where additional CABG is needed
- CABG in patients with porcelain aorta where clamping the aorta carries risk of embolization
An epicardial approach allows the surgeon to bypass blockages on arteries on the backside of the heart which cannot be reached from the inside. It is also useful when arterial grafts are not available.
How is an epicardial approach performed?
To access the heart’s surface, the surgeon must first make an incision through the chest wall, usually via a median sternotomy (incision down the breastbone) or right thoracotomy (incision between the ribs on the right side).
After separating the sternum or ribs, the pericardium is opened to reach the outer surface of the heart. The heart is often lifted out of the chest cavity using a special retractor to better expose the backside coronary arteries.
With the heart accessible, the surgeon can then perform coronary bypass with arterial or venous grafts on hard-to-reach vessels. For example, grafts may be placed on the posterior descending artery and posterior left ventricular branches which supply the back of the heart muscle.
Once the bypasses are completed, the chest is closed up with the sternum or ribs wired back together. Chest tubes are placed to drain fluid and allow the lungs to re-expand fully.
Benefits of an epicardial approach
Potential benefits of using an epicardial approach include:
- Ability to bypass any coronary blockage even in difficult to access arteries
- May allow complete revascularization in patients not candidates for traditional CABG
- Avoids risks of aortic manipulation and clamping
- Useful in redo CABG when prior grafts are no longer functional
Risks and limitations
Disadvantages and risks include:
- Increased risk of post-operative bleeding and need for transfusion
- Higher risk of damaging heart muscle compared to traditional CABG
- Longer operation and recovery times
- Higher incidence of post-operative atrial fibrillation
- More technically challenging surgery requiring experienced cardiac surgeon
Additionally, in some cases arterial grafts still cannot reach target vessels or provide adequate blood flow. There is also a small portion of the inferior heart surface that remains inaccessible.
Recovery after an epicardial approach
Recovering from an epicardial CABG follows a similar course to traditional CABG surgery. Patients can expect:
- 5-7 days in the hospital
- Chest tubes remaining in place for 1-3 days to drain fluid
- IV medications to control pain and prevent arrhythmias
- Breathing exercises and activity limited to walking
- Gradually advancing to a normal diet
- Continued monitoring of heart rhythm, chest tube output, and vital signs
However, the larger incisions and increased surgical trauma of the epicardial approach lead to more significant pain and limitations in activity in the early recovery period compared to minimally invasive surgery.
Long-term outlook
Over the long-term, epicardial CABG provides good to excellent results in properly selected patients. Bypassing coronary blockages from the outside gives the opportunity for complete revascularization even with complex disease. This leads to much improved blood flow to the heart muscle and relief of angina symptoms.
Graft patency rates are similar to traditional CABG. Arterial grafts have 10-year patency rates around 90%, while saphenous vein grafts remain open about 50-60% at 10 years. With continued medical management, symptoms can remain controlled for 15 years or longer in many patients.
However, due to the higher surgical risk, epicardial CABG may have slightly lower long-term survival compared to less invasive techniques. Patients with multiple medical problems are also at higher risk of complications after any major surgery.
Conclusion
An epicardial approach to coronary bypass surgery allows access to all heart vessels but comes at the cost of increased risk and recovery time. It is a vital tool for surgeons when traditional CABG methods are not feasible due to anatomy or previous surgery. Careful patient selection is necessary to balance the benefits and risks. With advances in less invasive surgery, epicardial CABG is used in only a small fraction of cases, but remains an important option in complex surgical cases.