Open Thoracoabdominal Aortic Aneurysm Repair: Does Chronic Dissection Differ From Aneurysm?

Aortic dissection is common in patients undergoing open surgical repair of thoracoabdominal aortic aneurysm (TAAA). Most often, this manifests as chronic dissection with progressive aortic dilatation. Because contemporary outcomes in chronic dissection are not clearly understood, we compared patient characteristics and outcomes after open TAAA repair between patients with chronic dissection and those with non-dissection aneurysm. We retrospectively analyzed data from 3700 open TAAA repairs performed within a single practice. Operations were for nondissection aneurysm in 2328 (62.9%), chronic dissection in 1185 (32.0%), and acute/subacute dissection in 187 (5.1%). Outcomes included operative mortality and adverse event, a composite variable comprising operative death and persistent (present at discharge) stroke, paraplegia, paraparesis, and renal failure necessitating dialysis. Binomial logistic regression identified independent predictors of operative mortality and adverse events. Competing risk analysis was performed to determine cumulative incidence of death, repair failure, and survival free of repair failure. Survival and repair failure were analyzed using Cox regression with adjustment for age, sex, hereditary thoracic aortic disease, aortic disease type, coronary artery disease, chronic kidney disease, and chronic obstructive pulmonary disease. Compared with patients with nondissection aneurysms, those with chronic dissection were younger, had fewer atherosclerotic risk factors, and were more likely to have heritable thoracic aortic disease and undergo extent II TAAA repair (Table). The overall operative mortality rate was 8.5% (n = 314); this was 9.1% (n = 211) in nondissection aneurysm and 6.9% (n = 82) in chronic dissection, which differed significantly (P = .03). Adverse events were lowest in cases of chronic dissection (n = 150, 12.7%), including 22 (1.9%) with persistent paraplegia. Chronic dissection was not predictive of operative mortality (P = .5) or adverse events (P = .6). Operative mortality and adverse events, respectively, were independently predicted by rupture (odds ratio [OR], 2.74; 2.63), emergency repair OR, 2.30; 1.94), chronic kidney disease (OR, 1.70; 1.91), extent II TAAA repair OR, 1.59, 1.71), increasing age OR, 1.04/year; 1.04/year), and increasing aortic cross-clamp time OR, 1.01/minute; 1.02/minute). Patients with chronic dissection had lower 10-year mortality (42% vs 69%), but more frequent repair failure (6% vs 3%) than patients with nondissection aneurysm (P < .001; Figure). The difference in survival was no longer significant after adjustment. Outcomes of open TAAA repair vary by aortic disease type. Rupture and atherosclerotic diseases most commonly occur in patients with nondissection aneurysm and are independently predictive of operative mortality. Repair of chronic dissection is associated with low rates of operative mortality, adverse events, and persistent paraplegia, along with reasonable late survival and excellent long-term durability.TablePreoperative characteristics, operative details, and early outcomes in 3513 open thoracoabdominal aortic aneurysm (TAAA) repairs stratified by aortic disease typeChronic dissection (n = 1185)Nondissection aneurysm (n = 2328)P value*Age, years57 [47-66]70 [65-75]<.001Male sex886 (74.8)1299 (55.8)<.001Heritable thoracic aortic disease465 (39.2)114 (4.9)<.001Coronary artery disease273 (23.0)972 (41.8)<.001Chronic kidney disease (estimated glomerular filtration rate <60)283 (23.4)(n = 1100)1091 (46.9)(n = 2136)<.001Maximum distal aortic diameter, cm6.2 [5.5-7.1] (n = 1081)6.3 [5.6-7.3] (n = 2045).3Rupture36 (3.0)176 (7.6)<.001Emergency repair65 (5.5)225 (9.7).01Extent II repair557 (47.0)600 (25.8)<.001Aortic clamp time, minutes61 [48-80] (n = 1177)46 [35-59] (n = 2318)<.001Prior open distal aortic repair250 (21.1)625 (26.8)<.001Adverse eventa150 (12.7)373 (16.0).008Operative death82 (6.9)211 (9.1).03Persistent paraplegia22 (1.9)79 (3.4).01Persistent renal failure59 (5.0)160 (6.9).03P values reflect two-way comparison of chronic aortic dissection and nondissection aneurysm.Values are number (%) or median [interquartile range]. Variables with missing data are clarified by available sample size.aAdverse event, a composite variable comprising operative death or persistent (present at discharge) stroke, paraplegia, paraparesis, or renal failure necessitating dialysis. Open table in a new tab