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Angiographic and electron-beam computed tomography studies of retrograde cardioplegia via the coronary sinus
1Department of Cardiovascular Surgery, Hôpital Broussais, Paris, France.
Insights
External coronary sinus occlusion significantly improves cardioplegia distribution in the interventricular septum compared to balloon occlusion. This technique optimizes myocardial protection during retrograde cardioplegic infusion.
Area of Science:
- Cardiovascular Surgery
- Cardiac Anatomy
- Medical Imaging
Background:
- Retrograde cardioplegia delivery via the coronary sinus aims for homogeneous myocardial protection.
- Current cannulation techniques may lead to uneven distribution of cardioplegic solution.
- Optimizing retrograde perfusion is crucial for preventing ischemic injury.
Purpose of the Study:
- To compare the distribution of cardioplegic flow using two coronary sinus cannulation techniques: internal balloon occlusion and external catheter occlusion.
- To evaluate the impact of cannulation method on myocardial opacification, particularly in the interventricular septum.
Main Methods:
- Cadaveric human hearts were used for retrograde cardioplegic infusion studies.
- Two cannulation techniques were assessed: internal coronary sinus occlusion (balloon inflation) and external coronary sinus occlusion (catheter).
- Angiographic and electron-beam computed tomographic (EBCT) imaging were employed to visualize flow distribution and myocardial enhancement.
Main Results:
- Internal occlusion resulted in preferential perfusion of certain veins, incomplete septal opacification, and a "steal phenomenon" into the right atrium.
- External occlusion demonstrated simultaneous perfusion of all venous channels and complete opacification of the interventricular septum.
- EBCT confirmed significantly greater myocardial enhancement in the septum with external occlusion (p < 0.0001).
- The right ventricular wall remained largely unopacified in both groups.
Conclusions:
- The technique of coronary sinus cannulation critically influences cardioplegic solution distribution.
- External coronary sinus occlusion is superior to internal balloon occlusion for achieving homogeneous cardioplegia delivery to the interventricular septum.
- Optimizing cannulation technique is essential for enhancing myocardial protection during retrograde cardioplegic infusion.
Abstract:
Retroperfusion of the coronary sinus does not provide homogeneous distribution of cardioplegic solution. The goal of this study was to analyze the distribution of flow during retrograde cardioplegic infusion in cadaveric human hearts with two different techniques of coronary sinus cannulation: (1) internal occlusion of the coronary sinus by balloon inflation and (2) external occlusion by tightening the orifice of the coronary sinus around a simple catheter. To evaluate differences between the two techniques, angiographic and electron-beam computed tomographic studies were performed. Computed digital angiography was performed on 14 hearts. Angiographic patterns varied according to type of coronary sinus cannulation. With the balloon inflation technique, the marginal vein and the anterior descending vein were perfused first; the posterior descending vein was not perfused. This vein was opacified secondarily through a venovenous anastomosis located at the apex of the heart. Backward flow into the right atrium (steal phenomenon) was demonstrated. At completion of retroperfusion, the inferior part of the septum remained poorly opacified. Conversely, angiographic findings after external occlusion of the coronary sinus revealed simultaneous injection of all venous channels. The entire septum was well opacified at completion of retroperfusion. Electron-beam computed tomographic study was performed on eight hearts with the external occlusion technique and nine with the internal occlusion technique. The computed tomographic findings confirmed the results of digital angiography. The peak myocardial enhancement and the peak rising rate of myocardial enhancement within the interventricular septum were significantly more important (p < 0.0001) when the external coronary sinus occlusion mode was used than when the internal coronary sinus occlusion mode was used. In all hearts except one, the right ventricular wall was not opacified, regardless of the type of cannulation and the type of radiologic analysis. This study demonstrates the importance of coronary sinus cannulation technique in optimizing the protection of the interventricular septum with retrograde cardioplegic infusion.