| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Eur J Cardiothorac Surg 2003;23:139
© 2003 Elsevier Science NL
Letter to the Editor |
Department of Surgery and Research Center, Montreal Heart Institute, Montreal, Québec H1T 1C8, Canada
Received 17 September 2002; received in revised form 17 September 2002; accepted 17 October 2002.
* Corresponding author. Tel.: +1-514-376-3330 ext. 3715; fax: +1-514-376-1355
e-mail: lpperrau{at}icm.umontreal.ca
Key Words: Iatrogenic left main coronary artery stenosis • Aortic valve replacement • Coronary artery bypass grafting
We read with great interest the case report by Yavuz et al. [1] about a severe iatrogenic stenosis of the left main coronary artery (LMCA) and proximal right coronary artery (RCA) after direct instillation of cardioplegia into the coronary ostia during an aortic and mitral valve replacements, 4 months earlier. We agree that this complication may be grossly underreported and may account for sudden death or adverse outcome after aortic valve replacement (AVR). In a recently published retrospective study, dating from 1987 to present [2], seven cases of iatrogenic left main coronary stenosis were observed at the Montreal Heart Institute, after 2158 AVR, representing 0.3% of all the cases. The interval between AVR and symptoms ranged from 4 to 11 months (mean: 7.3). The symptoms were usually severe unstable angina (5/7). The LMCA was involved in all cases with the stenosis ranged from 55 to 75% and one occlusion and, the RCA in only two cases. Intermittent antegrade cardioplegia had been used in three cases and continuous in four. The specific type of antegrade cannulation for cardioplegia, intermittent or continuous, may have some importance, because no catheters have the potential of producing the same trauma on the arterial wall.
Our surgical research group has focused for a number of years on the investigation of endothelial function as a marker of surgical intimal injury, especially for assessment of intracoronary devices such intracoronary shunts or cannulas to deliver cardioplegia or obtain hemostasis during off-pump coronary surgery, all of which can lead to endothelial dysfunction and chronic intimal hyperplasia [3]. In an experimental study, shunts were shown to create a severe endothelial dysfunction [4], due to the rubbing. However, the hydrodynamic pressure of the cardioplegia instilled may also play an additional role in creating injury.
Various systems have been developed such as simple intra coronary cannulas for intermittent cardioplegia, stiff or soft, which may create intimal lesions by rubbing, and cannulas with occlusive balloons for continuous cardioplegia to avoid repositioning and withdrawal which exert a constant transmural pressure on the arterial wall, creating trauma which may be deleterious over the period of time necessary for an AVR. The safest technique for morphological and functional preservation of the coronary artery endothelial and muscular layers remains to be established, but the smallest soft catheters inserted gently with intermittent administration of cardioplegia at low pressure (<100 mmHg) should be the preferred choice, if antegrade cardioplegia is necessary.
Direct cannulation of the coronary ostia remain very frequently used by surgeons during AVR and ascending aortic procedures. However, because of the risks described above, use of intracoronary cannulas to deliver cardioplegia must always be guided by the concern of inducing as little trauma as possible. Considering the pitfalls and dismal results of myocardial revascularization for iatrogenic LMCA stenosis after AVR [2], emphasis on prevention of this complication with systematic use of the retrograde route and judicious selective application of antegrade catheters remains of paramount importance.
References
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
