Remarkable progress has become especially apparent in aortic medicine in the last few decades, leading to essential changes in how thoracic aortic dissection is understood and treated. This state-of-the-art review article addresses the mechanisms of acute aortic dissection, explaining the role of its primary entry location, proximal, and distal dissection extension in their clinical presentation and impact on the decision-making process towards the best treatment approach. The latest evidence on novel treatment methods for acute aortic syndromes is presented, and the diverse dissection classification systems that remain uncertain are discussed, which reveals the need for shared terminology and more clarity. Finally, future aspects are discussed in treating acute aortic dissection, such as the endovascular treatment of aortic dissection Type A and biomarkers for acute aortic syndromes.

The aim of our study was to delineate the effect of aortic arch surgery extension on the outcomes in acute type A dissection extending beyond the ascending aorta. From 2001 to 2013, of 197 patients with type A dissection, 153 (78%) with dissection extending beyond the ascending aorta (age, 61 years; first quartile, 50; third quartile, 69; 67% men) were identified. Aortic repair involved isolated ascending replacement (n = 102), hemiarch (n = 37), and total arch replacement (n = 14). The median follow-up period was 4.9 years (first quartile, 2.5; third quartile, 7.6; 733 patient-years). In-hospital mortality was 9.8%, 21.6%, and 28.6% (P = .122) for patients with no, hemiarch, and total arch replacement. Age > 80 years (odds ratio [OR], 9.37; P = .006), malperfusion syndrome (OR, 4.74; P = .004), and total arch replacement (OR, 6.47; P = .016) were independent predictors of perioperative mortality. Freedom from distal reintervention was 93% ± 3%, 97% ± 3%, and 100% at 1 year and 89% ± 3%, 97% ± 3%, and 100% at 5 years for the no, hemiarch, and total arch replacement groups, respectively (log-rank, P = .440). Marfan syndrome (OR, 12.40; P = .038) and dissection of all aortic segments (OR, 10.68; P = .007) predicted distal aortic reintervention. In-hospital mortality for elective reintervention was 0%. Limiting the extent of surgery for type A aortic dissection to ascending aortic replacement was associated with low perioperative mortality. Thus, aortic arch repair can be deferred, because it can be performed electively with a lower mortality risk.

Aortic geometry changes throughout life are not well defined. This investigation delineates aortic geometry across the adult age spectrum and determines the gender-related influence of aging on aortic morphometry. Contrast-enhanced computed tomography scans of all aortic segments in 195 subjects (94 women, 101 men, average age 57 ± 20 years) free of vascular disease were analysed. Lengths and diameters of each aortic segment as well as width, height and tortuosity of the thoracic aorta were compared between both genders. Aortic diameters and lengths were larger in men than women (P < 0.001); however, after adjustment for body surface area (BSA), the ascending aorta and aortic arch revealed greater diameters in women than in men (P = 0.001 and P = 0.011, respectively). All aortic segment dimensions increased in a similar pattern with age for both genders, except the ascending aorta diameter, which increased +3.4% (P < 0.001) per decade in women and +2.6% (P < 0.001) per decade in men. Owing to more dynamic ascending aortic growth in women, absolute diameters were similar in both genders at an older age (>70 years old: 3.4 ± 0.3 vs 3.5 ± 0.3 cm, P = 0.241). Female gender is associated with smaller aortic dimensions, but only at a young age. The dynamics of aortic growth throughout life are greater in women than in men. Gender-related changes in aortic geometry provide a hypothesis for the predominance of aortic dissection in young male patients, which normalizes between genders with increasing age.

The current guidelines for ascending aortic replacement were determined from already dissected aorta diameters. Previous computed tomography-based work on humans who underwent imaging before and directly after aortic dissection onset has shown an average 30% increase in the ascending aortic diameter with acute dissection. The present investigation evaluated the incidence of predissection ascending aortic dilatation in acute type A dissection. From 2002 to 2013, 495 patients presented with acute type A aortic dissection to 1 center. Of these cases, 343 were non-Marfan, nonbicuspid with spontaneous dissection etiology. In those with available preoperative computed tomography angiograms (n = 83) or transesophageal echocardiograms (n = 260), the predissection ascending aorta diameters were modeled from the dissected aorta diameters by subtraction of the average diameter increase rate. Altogether 343 patients were included (age, 62 years; range, 53-73; 64% men). The median modeled predissection ascending diameter was 3.7 cm (first quartile, 3.3; third quartile, -4.1). Of the 343 patients, 334 (97%) and 315 (92%) had an ascending diameter before dissection onset of <5.5 cm and <5.0 cm, respectively. More than 60% of women and 70% of men had a nondilated ascending aorta before type A dissection onset. The median predissection ascending aortic diameter did not differ between women and men (3.7 cm; first quartile, 3.4; third quartile, 4.2; vs 3.7 cm; first quartile, 3.3; third quartile, 4.1; P = .810). More than 60% of patients with spontaneous, non-Marfan, nonbicuspid, type A dissection will have a nondilated ascending aorta before dissection onset. Only 3% would meet the criteria for elective ascending replacement to prevent aortic dissection. Additional research on the genetic and biochemical predictors of aortic dissection is essential.