Ann Thorac Surg 2003;75:1064-1065
© 2003 The Society of Thoracic Surgeons
Correspondence
Alternate technique of routing the in situ right internal mammary artery to graft the left anterior descending artery and its branches
Thomas A. Vassiliades, Jr, MD
The Pensacola Heart Institute, Pensacola, FL 32504, USA
e-mail: vassiliades{at}pol.net
To the Editor:
I have read with interest the article by Al-Ruzzeh and colleagues [1]. I would like to congratulate them on their excellent results. I concur with their findings and recommendations for the use of the pedicled (in situ) right internal mammary artery (RIMA) for grafting the left anterior descending artery. However, many cardiac surgeons have not adopted this technique because of the need for the RIMA to course across the midline and over the aorta, as stated in the discussion of Al-Ruzzeh and colleagues. To supplement their findings, I would like to outline an additional maneuver that has not been previously described. The new technique alters the course of the in situ RIMA so as to provide additional length as well as protect it from injury during reentry or cannulation during a future reoperation. The technique consists of the following steps:
- The RIMA is harvested completely, close to its origin from the subclavian artery.
- The patient is then heparinized and the RIMA is divided distally.
- The superior vena cava (SVC) is easily dissected away from its thin surrounding tissue at the level of the proximal RIMA.
- By passing an angled clamp under the SVC from medial to lateral and grasping the end of the RIMA (with minimal to no pedicle), it is passed posterior to
- the SVC and redirected from its original lateral position to one medial to the SVC.
- The innominate vein is easily freed from its surrounded tissue and off the aortic arch in a similar fashion.
- The RIMA is then passed posterior to the innominate vein (alternatively, the IMA can be passed under both the innominate vein and the aortic arch if additional length is needed) to emerge through the mediastinal fat directly over the main pulmonary artery and right ventricular outflow tract: a very favorable position to graft the left anterior descending artery; diagonal and occasionally ramus intermedius artery (Fig 1).
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Fig 1. (A) Conventional route of the in situ RIMA to the LAD courses anterior to the SVC and ascending aorta. (B) A more direct and less exposed route to the LAD and its branches courses the RIMA under the SVC, innominate vein and alternatively, the aorta. (a = artery; a/v = artery/vein; LAD = left anterior descending; PA = pulmonary artery; RAA = right atrial appendage; RIMA = right internal mammary artery; RV = right ventricle; SVC = superior vena cava; v = vein.)
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Using this technique, the RIMA consistently has 1 to 3 additional centimeters of length (compared to the anterior technique), and avoids the concerns of stretching the RIMA over the ascending aorta. In many patients, the length of the RIMA is sufficient to perform a sequential graft to the left anterior descending artery and diagonal coronary arteries. Furthermore, the course of the RIMA posterior to the SVC, innominate vein ± aortic arch and fairly high on the aorta protects it from reentry and cannulation. However, when grafting the circumflex with an in situ RIMA, I believe the transverse sinus still provides the most direct path [2].
References
- Al-Ruzzeh S., George S., Bustami M., et al. Early clinical and angiographic outcome of the pedicled right internal thoracic artery graft to the left anterior descending artery. Ann Thorac Surg 2002;73:1431-1435.[Abstract/Free Full Text]
- Puig LB, Net LF, Rati M, et al. A technique of anastomosis of the right internal mammary artery to the circumflex artery and its banches. Ann Thorac Surg 1984;38:533–4
