The double balloon cannula: a means to prevent backward flow of retrograde cardioplegia to the right atrium

Retrograde cardioplegia (RC) delivery may result in suboptimal myocardial protection, due to leakage of cardioplegia to the right atrium. This study was undertaken to assess the efficacy of a double balloon cannula (DBC) occluding the coronary sinus ostium during RC. Fifteen patients were randomly assigned to receive RC via a conventional cannula or via the DBC. Cardioplegia was started at 200 ml/min, and the flow rate (Q) was adjusted to obtain a perfusion pressure (P) of 25-40 mmHg. Blood samples were collected at 13 different time points. The CPK-MB and TnI levels were measured on each sample. The use of the DBC was associated with increased P (P=0.03) at a lower Q (P=0.02). The CK-MB levels were significantly increased in both groups (P<0.0001). However, the use of the DBC was associated with lower levels of CK-MB (P=0.002). A similar trend was observed for the TnI levels (peak 5.1+/-1.8 ng/ml vs. 8.7+/-5 ng/ml, P=0.11). Occlusion of the coronary sinus ostium improved the hemodynamic efficiency of the RC, and this resulted in reduced perioperative ischemic myocardial damage.