Use of continuous retrograde gaseous oxygen persufflation for myocardial protection during open heart surgery

The infusion of a cardioplegic solution is the standard method of myocardial protection during open heart surgery. However, this method interrupts the surgical procedure and it is difficult to ensure a bloodless surgical field. To address these problems, the effect of continuous retrograde gaseous oxygen persufflation (ROP) on myocardial protection was assessed in comparison to St. Thomas' solution (STS).

Eighteen adult mongrel dogs were divided into three groups of six. Group G received continuous ROP, Group C received STS every 30 min, and Group N received hypothermia alone during the 120 min hypothermic ischemia. The myocardial metabolism was assessed by measuring the coronary sinus lactate concentration, lactate extraction ratio (LER), coronary sinus lipid peroxidation (LPO) concentration, left ventricular myocardial adenosine triphosphate (ATP) concentration, and water content. Cardiac function was assessed by the percent recovery relative to the baseline.

In Group G, the lactate, LPO, and water content were significantly lower (P = 0.0062, P = 0.03, and P = 0.0065, respectively), and ATP was significantly higher (P = 0.028) than in Group C. The LER was only positive in Group G. In addition, the cardiac functions in Groups G and C were not significantly different.

Retrograde gaseous oxygen persufflation was not inferior to STS in regard to myocardial protection. This technique could therefore represent a potentially promising cardioplegic method.