Off-Pump Surgeries and Minimally Invasive Techniques
Over the years, efforts have been made to reduce complications and improve the outcomes of cardiac surgery. There is also a push to reduce costs and decrease length of stay associated with cardiac surgery. In the mid-1990s, advances were made that allow surgeons to perform coronary artery bypass on a beating heart. Further advances in technology and surgical techniques allow surgeons to perform coronary artery bypass and valve surgeries without the use of a midline sternotomy, using endoscopic techniques, and with the assistance of robotic technologies.
Objectives
In this chapter, you will learn:
1. How cardiac surgeries are performed without cardiopulmonary bypass
2. Several technologies and robotic devices that surgeons use to perform minimally invasive surgeries
3. What complications may occur as a result of a minimally invasive surgery
OFF-PUMP SURGERIES
Chapter 4 discusses the many complications associated with the use of cardiopulmonary bypass (CPB) during cardiac surgery. In an effort to reduce these complications, surgical techniques were developed that allow surgeons to operate without the use of CPB while the heart is still beating. This is often called off-pump coronary artery bypass (OPCAB). This method can only be used to operate on the surface of the heart; it cannot be used for patients who require valve surgery or any other surgery that requires cutting into the heart.
Either the use of strategically placed sutures or special positioning devices allows the surgeon to turn and position the heart to gain access to the surgical site. Bypass grafts are implanted in the manner discussed in Chapter 5. The one additional requirement is that the surgical site be held as still as possible. As the surgeon is sewing the graft to the coronary artery, a stabilization device must be used to hold that area still while the rest of the heart continues to beat. Stabilization devices are available that use either suction or pressure to hold this area still without damaging the heart muscle. Even with stabilization, this technique is more difficult than operating when the heart is still (cardiopulmonary standstill).
When OPCAB is performed, a perfusionist is on standby with a CPB machine. If there is bleeding that cannot be controlled, arrhythmias or ischemia that cannot be readily managed, or hemodynamic compromise when the heart is positioned, the patient will need to be placed on CPB and the heart stopped to complete the surgery.
Several studies have shown a decrease in mortality and need for blood transfusions with the use of OPCAB. Because CPB is not used, this technique may also decrease neurocognitive dysfunction, renal dysfunction, and atrial fibrillation. OPCAB may be performed using a midline sternotomy or may be combined with other minimally invasive techniques. Many surgeons no longer perform OPCAB unless combining the technique with a minimally invasive surgery. Others reserve this technique for patients with minimal coronary artery disease or for very high-risk patients for whom CPB needs to be avoided.
FAST FACTS in a NUTSHELL 
By avoiding CPB and operating on a beating heart, some of the complications associated with coronary artery bypass grafting (CABG) may be avoided.
MINIMALLY INVASIVE CARDIAC SURGERY
A number of techniques and technologies allow for cardiac surgery to be performed in a minimally invasive manner. Generally, “minimally invasive” refers to surgery without the traditional midline sternotomy. The goals of a minimally invasive surgery include the following:
• Create patent grafts at least as well as traditional coronary bypass surgery
• Have the patient return to baseline activity faster
• Decrease length of stay and cost of the surgery
• Decrease morbidity, mortality, and pain
Minimally invasive surgeries have been shown to meet some of these goals. In general, minimally invasive cardiac surgery decreases the need for blood transfusions, length of stay, and risk of infection. Patients also experience a faster recovery time. However, other complications of cardiac surgery may or may not be decreased by the use of minimally invasive techniques.
Patient selection for minimally invasive cardiac surgery is important. Smaller incisions may impede full access to the heart. In general, patients must have disease in noncalcified arteries on the front of the heart (left anterior descending artery [LAD] or right coronary artery [RCA]). The arteries that will have bypass grafts sewn in must not be too small (i.e., must be greater than 1.5 mm in diameter) and generally there should be only one or two blockages to bypass. If the diseased artery is intramyocardial (deep in the cardiac muscle instead of on the surface), minimally invasive surgery is not possible. Many surgeons will not use minimally invasive techniques on the morbidly obese due to the difficulty in performing surgery through a small incision in this population. Minimally invasive surgeries are especially beneficial in patients who meet the preceding criteria and who are at very high risk for complications during percutaneous coronary intervention and traditional cardiac surgery.
FAST FACTS in a NUTSHELL
