A simple, inexpensive method of heart retraction during coronary artery bypass surgery

[Is coronary artery bypass grafting under extracorporeal circulation the only technic that assures complete myocardial revascularization? Pros and cons]

Like other technical advances in medicine, the initial phase of rejection of off-pump revascularization has given way to its acceptance with some limitations. Today's main concern is whether the technique can be safely applied to access all coronary arteries, specially the postero-lateral vessels of the heart. We believe that off-pump CABG has proven to be an excellent alternative to the standard revascularization techniques avoiding the risks and complications of cardiopulmonary bypass (CPB). It can be applied to any case with minimal incidence of conversions thus avoiding the complications of CPB. In this debate we describe our technique, discuss our experience with complete myocardial revascularization, and suggest that the CPB machine should be a readily available tool for more complex cases rather than the current concept that it is an indispensable element for myocardial revascularization.

Experimental off-pump grafting of a circumflex branch via sternotomy using a suction device

BACKGROUND

We have shown previously in the pig that coronary artery bypass grafting on the beating heart may be facilitated by local cardiac wall immobilization by a suction device ("Octopus") applied to the anterolateral side of the heart. The purpose of this study was to investigate the feasibility of the method on the posterolateral side.

METHODS

In a consecutive series of 8 pigs, after median sternotomy, the posterior wall was taken hold of by the Octopus and subsequently brought up anteriorly and immobilized while hemodynamics were monitored. A posterolateral branch of the circumflex artery was grafted with the left internal mammary artery. After the coronary artery was ligated proximally, the heart was repositioned. At 6 weeks, bypass graft angiography and functional testing (postocclusion hyperemia testing) were performed. After sacrifice, histologic examination of the anastomosis was performed.

RESULTS

Dislocation of the heart to expose the distal anastomosis site caused a minor drop in mean arterial blood pressure from 71 +/- 14 (baseline) to 63 +/- 6 mm Hg (dislocated) (not significant) and recovery to 70 +/- 12 mm Hg, 15 minutes after repositioning. Cardiac output decreased from 4.0 +/- 1.0 to 3.2 +/- 0.7 L/min (p = 0.02) and recovered to 4.3 +/- 0.3 L/min. No inotropic drugs were necessary. Anastomosing required 21.5 +/- 6.5 minutes. Baseline graft flow was 8 +/- 3 mL/min and increased threefold to 24 +/- 10 mL/min (p < 0.05) at postocclusive hyperemia testing. At sacrifice after 6 weeks (n = 8), graft flow increased fourfold from 5 +/- 2 to 20 +/- 8 mL/min (p = 0.002) (n = 7). At histologic examination all eight anastomoses were patent without stenosis or mural thrombus.

CONCLUSIONS

Off-pump coronary artery bypass grafting of the posterolateral circumflex branches using the Octopus method on the beating pig heart is feasible, with full patency maintained for at least 6 weeks.

A new device for exposing the circumflex coronary artery

We have devised a new retractor for use in coronary artery bypass grafting that is made from three woven Teflon tapes. This method allows sufficient counterclockwise rotation of the heart, provides excellent exposure of the posterior and inferior coronary artery systems, and creates a horizontal surgical plane for the circumflex anastomosis.

Fabric heart retractor for coronary artery bypass operations

A new device for heart retraction during coronary artery bypass operations has been developed. It provides safe and steady support and an unobstructed view of the lateral, posterior, and inferior surfaces of the heart; in addition, it is easy to handle.

Cardiac retractor for coronary bypass operations

The Thompson retractor, used mainly for abdominal procedures, has been used to retract the heart and facilitate exposure for the performance of inferior wall or posterolateral wall coronary anastomoses. It has been found to be very effective and can replace a second assistant to retract the heart or avoid other cumbersome methods of cardiac retraction.