J Thorac Cardiovasc Surg 1994;108:1157-1158
© 1994 Mosby, Inc.
Determination of positioning of coronary sinus cannula for retrograde cardioplegia with intraoperative myocardial contrast echocardiography
Nobuaki Hirata, MD,
Kei Sakai, MD,
Masakatsu Ohtani, MD,
Kenji Ohnishi, MD,
Hikaru Matsuda, MD
Division of Cardiac Surgery
Sakurabashi Watanabe Hospital
Osaka, Japan
To the Editor:
The benefits of coronary sinus cardioplegia are well known, and recent developments in cannulas that allow blind intubation of the coronary sinus through a small pursestring suture in the right atrium have made this the most commonly used retrograde method
1, 2 However, the positioning of the cannula tip with certainty is difficult. The posterior interventricular vein drains into the distal part of the coronary sinus, about 8 mm from its termination in the right atrium, a distance estimated from the venous phase of coronary arteriography in 21 consecutive patients (Fig. 1).
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Fig. 1. Coronary venogram obtained from venous phase of coronary arteriography (50-degree left anterior oblique projection tilted 20 degrees to the cranial direction). The posterior interventricular vein drains into the distal part of the coronary sinus. GCV, Great cardiac vein; LV, left ventricular.
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The posterior interventricular vein receives the blood from the right half of the diaphragmatic wall of the left ventricle, from the diaphragmatic wall of the right ventricle, and from the posterior third of the ventricular septum. 3. Gundry and associates 2 reported that effective global myocardial cooling is achieved even if the catheter is positioned beyond the posterior interventricular vein. However, we think that direct delivery of the cardioplegic solution is necessary for myocardial protection of the regions drained by the posterior interventricular vein in more severe cases, the number of which has increased.
We performed myocardial contrast echocardiography to assess the retrograde delivery of cardioplegic solution during cardiac operations. Epicardial echocardiographic images of the short axis of the left ventricle at the papillary muscle level were obtained before and after injection of 4 ml sonicated albumin into the transatrial coronary sinus cannula during delivery of cardioplegic solution.
Cardioplegic solution delivered by the retrograde route did not disperse to the inferior and inferoseptal regions of the left ventricle. However, if the cannula was placed less deeply, delivery to the inferior wall, the region drained by the posterior interventricular vein, became evident (Fig. 2). Accordingly, we think that delivery to the posterior interventricular vein was thus obtained.
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Fig. 2. Myocardial contrast echocardiogram obtained at short-axis angle of the left ventricle at the level of the midpapillary muscle before and after the cannula was repositioned. After the cannula was positioned less deeply, the area of myocardial enhancement enlarged to include the inferior wall of the left ventricle.
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In conclusion, intraoperative use of myocardial contrast echocardiography has proved useful in ascertaining the position of the cannula tip.
References
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Chitwood WR Jr. Retrograde cardioplegia: current methods. Ann Thorac Surg 1992;53:352-5.[Abstract]
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Gundry SR, Sequiera A, Razzouk AM, McLaughlin JS, Bailey LL. Facile retrograde cardioplegia: transatrial cannulation of the coronary sinus. Ann Thorac Surg 1990;50:882-7.[Abstract]
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Tschabitscher M. Anatomy of coronary veins. In: Mohl W, Wolner E, Glogar DH, eds. The coronary sinus. Proceedings of the first international symposium on myocardial protection via the coronary sinus. Darmstadt: Steinkopff Verlag Darmstadt Inc., 1984:8-25.
