Is the abdominal aortic aneurysm rupture rate decreasing?

Engineering In Situ Weldable Vascular Devices

(1) Background: The minimally invasive implantation of medical devices is largely limited by their insertion profile, and, therefore, minimizing them constitutes a leading trend in the field. (2) Methods: This study introduces the in situ welding strategy, whereby the components of the stent grafts used to treat abdominal aortic aneurysms were decoupled, deployed sequentially, and welded together at the aneurysmal site, greatly reducing their insertion profile. Polyurethane elastomers were used to produce the graft and to coat the metallic struts of the stent to render it in vivo weldable. Results: The composition of the polyurethanes was fine-tuned, so to minimize the insertion profiles and optimize the welding properties and the clinical performance of the devices assembled. The stent and graft were deployed successively in pigs via a small 8F introducer, in situ welded, and the patency of the bi-component device was confirmed over a three-month post-implantation period. The strength of the stent/graft welded connection was fully retained, with no de-welding observed. Conclusions: The in situ welding strategy resulted in implantations that were easier to perform and markedly less injurious to tissues and organs, largely expanding the applicability of these ultra-minimally invasive procedures to especially frail segments of the population.

Angiotensin-Converting Enzyme 2 Inhibits Angiotensin II-Induced Abdominal Aortic Aneurysms in Mice

Recent studies have demonstrated that angiotensin-converting enzyme 2 (ACE2) plays an important role in the pathogenesis of abdominal aortic aneurysms (AAAs). However, few studies have reported the direct effect of ACE2 overexpression on the aneurysm. This study hypothesized that the overexpression of ACE2 may prevent the pathogenesis of aneurysms by decreasing RAS activation. Thirty-nine mice were randomly assigned to three groups (n = 13 in each group): the Ad.ACE2 group, the Ad.EGFP group, and a control group. After 8 weeks of treatment, abdominal aortas with AAAs were obtained for hematoxylin and eosin staining, Verhoeff Van Gieson staining, immunohistochemistry, and Western blotting. The incidence and severity of AAAs, macrophage infiltration, and MMP protein expression were all recorded. The results showed that ACE2 gene transfer significantly decreased the occurrence of AAAs and inhibited AAA formation in ApoE^-/- mice by inhibiting the inflammatory response and MMP activation, and the mechanisms may involve decreased ERK and Ang II-nuclear factor kappa B signaling pathways.

Persisting disparities between sexes in outcomes of ruptured abdominal aortic aneurysm hospitalizations

We sought to describe and analyze discrepancies between sexes in the outcomes of patients hospitalized for ruptured abdominal aortic aneurysms (rAAA) by conducting a retrospective analysis of the Nationwide Inpatient Sample. The review included all adult patients (≥18 years old) hospitalized with a primary diagnosis of rAAA between January 2002 and December 2014. In-hospital mortality differences between females and males were analyzed overall and separately among those receiving endovascular AAA repair (EVAR) or open AAA repair (OAR). In-hospital mortality for females declined from 61.0% in 2002 to 49.0% in 2014 (P for trend <0.001), while mortality for males declined from 48.6% in 2002 to 32.2% in 2014 (P for trend <0.001). Among those receiving EVAR, females were significantly more likely to die in the hospital than males (adjusted odds ratio [OR], 1.44; 95% CI, 1.12-1.84). In addition, the odds of mortality among those receiving OAR were higher for females than males (adjusted OR, 1.14; 95% CI: 1.00-1.31). These data provide evidence that despite overall decreasing trends in mortality for both sexes, females remain at higher risk of death compared with males regardless of surgical repair procedure.

Epidemiology of ruptured abdominal aortic aneurysms in a well-defined Norwegian population with trends in incidence, intervention rate, and mortality

OBJECTIVE

Ruptured infrarenal abdominal aortic aneurysms (rAAAs) represent both a life-threatening emergency for the affected patient and a considerable health burden globally. The aim of this study was to investigate the contemporary epidemiology of rAAA in a defined Norwegian population for which both hospital and autopsy data were available.

METHODS

This was a retrospective, single-center population-based study of rAAA. The study includes all consecutively diagnosed prehospital and in-hospital cases of rAAA in the catchment area of Stavanger University Hospital between January 2000 and December 2012. Incidence and mortality rates (crude and adjusted) were calculated using national demographic data.

RESULTS

A total of 216 patients with primary rAAA were identified. The adjusted incidence rate for the study period was 11.0 per 100,000 per year (95% confidence interval [CI], 9.6-12.5). Twenty patients died out of the hospital, and 144 of the 196 patients (73%) admitted to the hospital underwent surgery. The intervention rate varied from 48% to 81% during the study period. The adjusted mortality rate was 7.5 per 100,000 per year (95% CI, 6.3-8.8). No differences in the incidence and mortality rates were found in comparing early and late periods. The 90-day standardized mortality ratio for the study period was 37.2 (95% CI, 31.6-43.7). The overall 90-day mortality was 68% (146 of 216 persons) and 51% (74 of 144 persons) for the patients treated for rAAA.

CONCLUSIONS

We found a stable incidence and mortality rate during a decade. The prehospital death rate was lower (9%), the intervention rate (73%) higher, and the total mortality (68%) lower than in most other studies. Geographic and regional differences may influence the epidemiologic description of rAAA and hence should be taken into consideration in comparing outcomes for in-hospital mortality and intervention rates.