The preceding article represents an important contribution because it calls attention to a rare, often complex, life-threatening injury and also provides a discussion of the merits of conventional surgery versus endovascular treatment. With respect to use of endovascular techniques, larger Wallstents, capable of 24- to 25-mm expansion, and bifurcated aortic endovascular stent grafts have, for the most part, resolved difficulties associated with stenting the entire area of dissection. Although small intimal tears can sometimes be managed successfully by observation alone, such patients require prolonged, close follow-up with periodic, contrast-enhanced, spiral CT scans and/or angiography. Contrary to the authors' statements, I believe that fenestration and dilation of the dissection septum between the true and false lumens, with or without stenting, is a safe and effective means for treating branch vessel occlusions, secondary to external compression of the true lumen by the dissection. The etiology of paraplegia after infrarenal aortic dissection is multifactorial, but the major cause is an alteration in the blood supply to the spinal cord, primarily via the great radicular artery (GRA). Even though studies have yielded different results, there is a consensus that the GRA arises between T-5 and L-4, most frequently between T-9 and L-1 levels.1Carmichael S.W. Gloviczki P. Anatomy of the blood supply to the spinal cord the artery of Adamkiewicz revisited.Perspectives Vasc Surg. 1999; 12: 113-122Crossref Scopus (11) Google Scholar Djindjian and Faure,2Djindjian R, Faure C. Accident médullaires de l'aortographie [French]. J Belg Radiol 1967;50:207-18Google Scholar in an angiographic study, located the GRA between T-9 and T-12 in 75% of cases, T-5 and T-8 in 15%, and L-1 or L-2 in 10%. Blood to the distal cord is also supplied by the pelvic circulation, and paraplegia following infrarenal aortic reconstruction can be caused by embolization and/or thrombosis of the internal iliac arteries. Moreover, prevention of prolonged hypotension is of paramount importance. Finally, I wish to mention two patients in whom paraplegia occurred shortly after infrarenal aortic dissection caused by a steering wheel injury. In each patient, the dissection was complicated by thrombotic occlusion of the infrarenal aorta and iliac arteries as well as an inordinate amount of clotting in both lower extremities. Despite repeated use of Fogarty embolectomy catheters and graft replacement of the aorta and common iliacs, satisfactory flow could not be established below the femoral arteries, and both patients died. The presence of extensive clotting in these patients suggested the possibility of a hypercoagulable state initiated by the injury.3Nunn D.B. Abdominal aortic dissection following non-penetrating abdominal trauma.Am Surgeon. 1973; 39: 177-179PubMed Google Scholar, 4Nunn DB. Discussion of James D. Hardy's paper, “Aortic and other arterial injuries.” Proceedings of the Southern Surgical Association; 1974. Vol 86, p. 154-67 [discussion on p. 166-7]Google Scholar