"KEYHOLE" CORONARY ARTERY BYPASS SURGERY
results and shortcomings
Rodney J. Landreneau, M.D.*
James A. Magovern, M.D.*
Michael J. Mack, M.D.#

Allegheny University of Health Sciences*
Pittsburgh, Pennsylvania

and

Medical City#
Dallas, Texas

       From October 1995 to the present we have utilized the "Keyhole" coronary artery bypass (CABG) approach to accomplish isolated internal mammary bypass to the left internal mammary artery (n=98), proximal right coronary artery (n=7), and the first diagonal branch (n=4).  These patients represent 90% (109/121) of those individuals in whom this approach was initiated.  The twelve patients requiring conversion to an open sternotomy apoproach had this done because of inadequate internal mammary conduits, poor target vessel at the site of the mini-thoractomy, or hemodynamic instability during coronary arterial occlusion.  We have also performed one secondary bypass to a diagonal branch from a left internal mammary artery pedicle primarily anastormosed to the LAD.  The mean age of our patients was 62(+/-)11.2 years and 23% (n=25) were women.  Their median NYHA anginal class was III.  The mean left ventricular ejection fraction was 54%.  Femoral cardiopulmonary bypass support was utilized in 14 patients (13%) with the remainder having only percutaneous femoral artery and vein cannulation with angio-access guide wires.  Lateral intercostal access for thorascopic takedown of the internal mammary artery was utilized in 25 patients; video assisted takedown through small anterolateral thoractomy access was used in 47 patients and takedown through the small anterolateral thoractomy access was used in 47 patients and takedown under direct vision through the minithoracomy was used in 37 patients.  Local vessel isolation was utilized to accomplish standard anastmotic techniques without earlier cardiac arrest.  Short acting beta blockade with intravenous esmolol was selectively utilized to reduce the heart rate and the vigor of ventricular contraction.  Adenosine was selectively utilized to accomplish temporary cardiac standstill.
         All patients have survived operation  averaging 131 minutes (IMA takedown - 38 minutes and the CABG - 16 minutes).  The mean hospital stay has been 3.4 days.  Postoperative blood transfusion was required in 17% of patients (n=18).  Significant postoperative complications occurred in 6 patients.  Three patients suffered thoracotomy wound infections; one patient undergoing femoral access for cardiopulmonary bypass developed lower extremity ischemia requiring femoral arterial thrombectomy and repair.; and two patients required prolonged respiratory support.  There have been no intraoperative or postoperative infarctions, however, postoperative ischemia manifesting as angina (n=5), isolated electocardiographic changes (n=2), or nuclear scintigraphic evidence of hypoperfusion (n=1) indentified anastomic stenoses in 7.5% of patients.  Percutaneous transluminal angioplasty was sucessful in relieving these stenoses and controlling ischemia in all instances.
         At the present time, "Keyhole" CABG is primarily limited to internal mammary bypass of the LAD and Proximal RCA.  Due to limited cardiac access through the direct mini anterolateral thoracotmy and inability to address lesions in the circumflex marginal and distal right coronary arterial circulation, multi-vessel bypass will be difficult to accomplish utilizing present approaches.  Development of effective peripheral cardiopulmonary bypass support and cardioplegia delivery systems will aid in expanding the role of "Keyhole" CABG and reducing the likelihood of anastomotic problems.  However, in order to truly expand the role of these interventions to multi-vessel coronary disease, cardiothoracic surgeons will have to develop skill in the performance of more advanced endosurgical anastomotic techniques or change the mind set regarding the combined use of endovascular interventions with "Keyhole" CABG.