Beating Heart Surgery - Introduction

INTRODUCTION

Coronary artery bypass grafting (CABG) has come full circle. Prior to the introduction of cardiopulmonary bypass (CPB), CABG procedures were performed on a beating heart. However, the emergence of CPB and methods of myocardial protection revolutionized CABG procedures by providing a bloodless, motionless heart. CPB has allowed almost all surgeons to perform a safe operation with excellent graft patency rates. Despite the success of CABG with CPB, the deleterious effects of CPB are well documented. At the same time, Buffolo and Benetti have shown in their respective studies, each with large series of patients, that beating heart CABG can be performed safely with results similar to CABG with CPB.¹^,2 Today, advances in technology are enabling a near bloodless arteriotomy and near motionless target area to ease the technical difficulty of performing a beating heart anastomosis.

Hazards of Cardiopulmonary Bypass

Because of the increasing use of endovascular technologies and the advancing age of patients, surgical candidates are presenting with more and more comorbidities. Comorbidities can dramatically complicate procedures using CPB, which itself has the potential to cause multiple complications:³

Stroke and neurocognitive defects ⁴
Immunosuppression
Systemic inflammatory response:
- Bleeding complications secondary to platelet dysfunction
- Renal insufficiency
- Pulmonary insufficiency

In addition, myocardial protection can lead to cardiac complications, such as perioperative myocardial infarction. In general, CPB leaves patients feeling like they have been "hit by a truck," and their recovery can take weeks to months.³

Early Outcomes of Beating Heart CABG

Patients realize substantial benefits when undergoing beating heart CABG instead of CABG with CPB. Clinical studies comparing outcomes of beating heart CABG and CABG with CPB have reported that patients undergoing beating heart CABG have benefited in the following ways:

Shorter postoperative hospital stays ^5,6,7
Shorter time with ventilatory support ^5,6
Less blood loss and need for transfusions ^5,6,8
Less likelihood of low output syndrome ⁸
Reduced systemic inflammatory response ⁵
Fewer arrhythmia and neurologic postoperative complications ⁹
Potential cost savings ⁶^,10

Importantly, research has indicated that beating heart CABG is not associated with increased rates of mortality ^5,6,7,8 or perioperative myocardial infarction ^5,6,9 when compared to CABG with CPB. Even though beating heart CABG provides notable benefits over CABG with CPB, patency rates are the ultimate measure of whether or not a patient is receiving a comparable outcome. Early results indicate that patency rates achieved in beating heart CABG are similar to those achieved in CABG with CPB (Table 1).

Table 1. Patency rates for multivesse beating heart CABG

Study	Number of Patients	Number of Anastomoses	Patency Rate
Calafiore et al.⁷	78	211	98.6%
Jansen et. al.¹¹	86	147	95%

Getting Started

Although beating heart CABG is a technically demanding procedure, it can be mastered. Mastery can be achieved through a progression of experience. The progression of experience may be obtained by following the steps below:

1. Start performing beating heart anastomoses now with the support of CPB:

Start with the easier grafts and perform them with the heart partially vented and beating.
Progress to performing all of the grafts on a nonvented, beating heart.

2. Perform your first beating heart CABG procedure on a patient with good target arteries and conduits.
3. As your comfort level with the procedure increases, more patients will be appropriate candidates.

Successful beating heart CABG requires the understanding that it is a different procedure, not just a new technique. As a result, every member of the operating room (OR) team, including the anesthesiologist, must be included in the educational process. The following pages present tips and techniques for beating heart CABG, from preoperative planning to postoperative observations.