| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 2001;72:1445
© 2001 The Society of Thoracic Surgeons
a Department of Cardiovascular Surgery, Escorts Heart Institute and Research Centre, Okhla Rd, New Delhi 110025, India
e-mail: meharwal{at}hotmail.com
To the Editor
The article by Chavanon and colleagues [1] in the January 2001 issue of The Annals is quite interesting and raises the important issue of iatrogenic aortic dissection. Off-pump coronary artery bypass grafting is being used by more and more surgeons all over the world, and although prospective, randomized trials are lacking, several authors have reported a decrease in mortality in certain high-risk groups including older age patients. The incidence of atherosclerosis in the aorta increases with age, and these are the patients in whom complications secondary to aortic clamping might be expected to be high. Off-pump coronary artery bypass procedures do not use aortic cannulation and cross-clamping and thereby avoid injury to the aorta and dislodgment of any atheroma during bypass. However, there is certainly a risk of injury to the aortic wall during partial clamping of a tense aorta, especially if it is diseased.
Chavanon and associates did not attempt to reduce arterial pressure in the first 100 patients and then lowered the pressure to 100 mm Hg for the next 208 patients. They did not mention their technique for screening the aorta, ie, transesophageal echocardiography or epiaortic scanning. Some of the patients who had dissection might have had major atherosclerosis of the aorta. Epiaortic scanning is superior to transesophageal echocardiography in detecting atheroma in the ascending aorta and assessing target sites for surgical procedures involving the ascending aorta [2]. The high aortic pressure during application of the partial occlusion clamp will be a risk factor for injury to the aortic intima especially in the older patient and the patient with a diseased aorta. We reduce the pressure to 60 to 70 mm Hg while applying the clamp.
Between December 1996 and December 2000, we performed 2,560 OPCAB procedures. One intraoperative dissection of the aorta occurred. The ascending aorta was replaced with a prosthetic graft and the proximal anastomosis of the vein conduit was placed on the prosthesis. In patients in whom atheromatous disease in the aortic arch is shown by transesophageal echocardiography or in whom the aorta feels diseased on superficial palpation, we transiently clamp the venae cavae and reduce the pressure to low levels (50 to 60 mm Hg) to palpate the aorta. If there is any sign of substantial aortic atherosclerosis or calcification, we either avoid doing the proximal anastomosis on the aorta or apply a small pediatric partial occlusion clamp in an area of the aorta that feels normal. When the aorta is diffusely diseased, we perform Y grafts and sequential anastomoses. Recently we have started using epiaortic scanning in more and more patients, especially those who either have atheromas detected by transesophageal echocardiography or have signs of atherosclerosis on palpation.
References
Related Article
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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 |
