Malperfusion of the thoracoabdominal vasculature in aortic dissection

Ischemic damage to vital organs supplied by the thoracoabdominal aorta greatly increases the overall risk of aortic dissection. Of 320 patients operated upon for aortic dissection since 1985, 33 (10.3%) underwent operations directed at the relief of malperfusion (15/158 acute type A; 9/18 acute type B; 4/78 chronic type A; 5/66 chronic type B). Organs affected were the kidneys in 32; the bowel in 20; and the spinal cord in 1, while critical lower extremity ischemia was present in 11 patients. In total, 64 vascular areas were affected. Fenestration of the dissecting membrane with or without infrarenal grafting was the procedure performed most frequently in 25, followed by replacement of the descending or thoracoabdominal aorta in 6, and bypass grafting or direct revascularization of individual side branches in 6. Six other operations targeted at the affected organs were done. Twenty-four patients underwent one-stage operation for malperfusion; in 11, early reoperation after primary aortic repair was necessary, while 2 patients were operated electively. Ten of 33 patients died in hospital, 7 of malperfusion-induced complications. Of three late deaths, one was related to sequelae of malperfusion. We conclude that immediate diagnosis and prompt relief of malperfusion offer the best prospects for patient survival. Membrane fenestration appears to be the method of choice for treating malperfusion in most patients, and must be directed to the level of aortic and/or side branch obstruction.