Analysis of intimal extent and predictors of renal atrophy in patients with aortic dissection

Background: The intimal flap of aortic dissection may extend to the abdominal branches and probably lead to malperfusion syndrome. Renal malperfusion and renal atrophy are significantly related to patient outcomes. Purpose: To study the extent of the intimal flap and predisposing factors for renal atrophy in patients with aortic dissection. Material and Methods: From January 2001 to June 2008, 176 (137 men, aged 21-86 years, mean 51.9 years) of 225 subjects with aortic dissection and computed tomography (CT) met the inclusion criteria for this study. Of these 176 patients, 35 (19.9%) developed unilateral renal atrophy. A review of the CT was conducted to classify aortic branch vessel perfusion into three types: type 1, in which the branch vessels are perfused exclusively from the true lumen; type 2, in which the branches are perfused from both the true and false lumens; and type 3, in which the branches are perfused exclusively from the false lumen. Variables including age, gender, type of aortic dissection, type of perfusion of the abdominal branches, and the presence of thrombi in the false lumen were analyzed to determine whether these factors were related to the left or right side and global or focal renal atrophy. Results: Of 880 abdominal branches in 176 patients, 622 (70.7%) were classed as perfusion type 1, 50 (5.7%) as type 2, and 208 (23.6%) as type 3. Type 3 perfusion was most commonly observed in the left renal artery, at a frequency of 31.7% (66/208). Partial thrombosis in the false lumen above the level of the renal arteries was seen in 68.8% of patients; such thrombi and type 3 perfusion of the renal artery were significantly related to renal atrophy. The laterality (left or right) and extent (global or focal) of renal atrophy were not related to age, gender, type of aortic dissection, or perfusion type. Conclusion: Type 3 perfusion is most frequent in the left renal artery, and such perfusion and partial thrombi in the false lumen above the renal arteries are significantly related to the development of renal atrophy.