J Thorac Cardiovasc Surg 1998;116:659
© 1998 Mosby, Inc.
Commentary
Richard A. Jonas, MD
Boston, Mass
In this case report, Delgado and Barturen have described a 5-year-old patient with an extremely unusual combination of aortic arch anomalies and anomalies of the circle of Willis. There is no connection from the aortic arch to the left common carotid and left subclavian arteries, which represent an isolated segment of a left aortic arch. In addition, there is a severe coarctation that incorporates the origin of the right subclavian artery from the right-sided aortic arch. There is absence of a complete circle of Willis, so that the posterior cerebral circulation is separate from the anterior cerebral circulation. These findings illustrate nicely the embryology of aortic arch development, as well as the potential for arch stenosis (coarctation) or interruption to occur at points of junction of the various segments of the developing aortic arches.
Delgado and Barturen felt uncomfortable in offering surgical repair to this girl because of their concern regarding a high risk of either cerebral or spinal cord ischemic injury. However, the patient has a left ventricular pressure of greater than 200 mm. The coronary arteries are exposed to a pressure of 211/137 mm Hg. Furthermore, the anterior cerebral circulation is entirely dependent on the right common carotid artery, and there is a steal into the left common carotid system through the circle of Willis. The posterior cerebral circulation is entirely dependent on the right vertebral artery with a steal into the left subclavian system. Although the risks of surgery are undoubtedly greater than the usual risks for coarctation repair, the various problems described above in my opinion justify the risks of surgical repair. I recommend to the authors that they consider the use of deep hypothermic circulatory arrest with a combination of both surface and core cooling. A connection should be established between the proximal aortic arch and the left subclavian/carotid system. Perhaps this could be achieved by turning down the left subclavian artery, although this might risk the viability of the left arm. An alternative would be to insert a polytetrafluoroethylene interposition tube graft. The coarctation should be dealt with by resection and end-to-end anastomosis, if possible, including reimplantation of the right subclavian artery. This procedure should reduce left ventricular pressure and ascending aortic pressure to a normal level and should provide bilateral supply to the anterior and posterior cerebral circulation.
