Continued expansion of aortic necks after endovascular repair of abdominal aortic aneurysms

AbstractBackground: Longitudinal studies have revealed that the aortic segment proximal to an infrarenal abdominal aortic aneurysm (AAA) is at risk for continued enlargement after a standard aneurysm repair. Similarly, preliminary reports have shown expansion of one or both aortic necks after endovascular repair. Although some investigators have suggested that this may be a transient effect, continued dilatation at the endograft attachment site could effect the overall device stability. Methods: As part of a multi-institutional trial of endovascular grafting for the treatment of AAA, 59 patients were successfully implanted with straight endografts between February 1993 and January 1995. A morphometric analysis of aortic neck size was undertaken with serial review of computed tomography scans available through April 1997. The neck sizes at both graft attachment sites were measured, with investigators blinded to patient identity and date of scan. Changes in minor diameter were defined, annual interval expansion rates were calculated, and the data were correlated with endoleak, device migration, aneurysm size change, endograft diameter, attachment system fractures, and initial preimplant neck size. Results: Significant aortic neck enlargement, particularly at the level of the distal neck, was observed for at least 24 months after AAA repair. The annual interval dilation rates of the proximal aortic neck were 0.7 ± 2.1 mm/y (P = .023) and 0.9 ± 1.9 (P = .008) mm/yr during the first and second years, respectively. Enlargement of the distal neck during the observation period was more marked, with corresponding annual expansion rates of 1.7 ± 2.9 mm/y (P < .001) and 1.9 ± 2.5 (P < .001) mm/year. In 5 patients (14%), the minor diameter of the distal neck was at least 6 mm larger than the preimplant diameter of the graft. Migration of the distal attachment system was observed in 3 of these 5 patients. Expansion rates did not have a statistically significant correlation with initial neck size, endograft dimensions, aneurysm size change, presence of endoleak, or attachment system fracture. Conclusions: Aortic neck enlargement was observed for at least 2 years after endovascular grafting. Close patient follow-up remains mandatory in lieu of the potential risk of late failure as a result of continued aortic expansion. The relative contribution of device design to this phenomenon will need to be defined. (J Vasc Surg 1998;28:422-31.

The evolutionary legacy of size-selective harvesting extends from genes to populations

Size-selective harvesting is assumed to alter life histories of exploited fish populations, thereby negatively affecting population productivity, recovery, and yield. However, demonstrating that fisheries-induced phenotypic changes in the wild are at least partly genetically determined has proved notoriously difficult. Moreover, the population-level consequences of fisheries-induced evolution are still being controversially discussed. Using an experimental approach, we found that five generations of size-selective harvesting altered the life histories and behavior, but not the metabolic rate, of wild-origin zebrafish (Danio rerio). Fish adapted to high positively size selective fishing pressure invested more in reproduction, reached a smaller adult body size, and were less explorative and bold. Phenotypic changes seemed subtle but were accompanied by genetic changes in functional loci. Thus, our results provided unambiguous evidence for rapid, harvest-induced phenotypic and evolutionary change when harvesting is intensive and size selective. According to a life-history model, the observed life-history changes elevated population growth rate in harvested conditions, but slowed population recovery under a simulated moratorium. Hence, the evolutionary legacy of size-selective harvesting includes populations that are productive under exploited conditions, but selectively disadvantaged to cope with natural selection pressures that often favor large body size.Peer reviewe

Excess Mortality for Abdominal Aortic Aneurysms and the Potential of Strict Implementation of Cardiovascular Risk Management: A Multifaceted Study Integrating Meta-Analysis, National Registry, and PHAST and TEDY Trial Data

Objective: Previous studies imply a profound residual mortality risk following successful abdominal aorta aneurysm (AAA) repair. This excess mortality is generally attributed to increased cardiovascular risk. The aim of this study was (1) to quantify the excess residual mortality for patients with AAA, (2) to evaluate the cross sectional level of cardiovascular risk management, and (3) to estimate the potential of optimised cardiovascular risk management to reduce the excess mortality in these patients. Methods: Excess mortality was estimated through a systematic review and meta-analysis, and through data from the Swedish National Health Registry. Cardiovascular risk profiles were individually assessed during eligibility screening of patients with AAA for two multicentre pharmaceutical AAA stabilisation trials. The potential of full implementation of cardiovascular risk management was estimated through the validated Second Manifestations of ARTerial disease (SMART) risk scores algorithm. Results: The meta-analysis showed a similarly impaired survival for patients who received early repair (small AAA) or regular repair (≥ 55 mm), and a further impaired survival for patients under surveillance for a small AAA. Excess mortality was further quantified using Swedish population data. The data revealed a more than quadrupled and doubled five year mortality rate for women and men who had their AAA repaired, respectively. Evaluation of the level of risk management of 358 patients under surveillance in 16 Dutch hospitals showed that the majority of patients with AAA did not meet therapeutic targets set for risk management in high risk populations, and indicated a more pronounced prevention gap in women. Application of the SMART risk score algorithm predicted that optimal implementation of risk management guidelines would reduce the 10 year risk of major adverse cardiovascular events from 43% to 14%. Conclusion: Independent of the rupture risk, AAA is associated with a worryingly compromised life expectancy with a particularly poor prognosis for women. Optimal implementation of cardiovascular risk prevention guidelines is predicted to profoundly reduce cardiovascular risk

Comparison of thoracic aortic diameter changes after endograft placement in patients with traumatic and aneurysmal disease

No Abstract

Endovascular repair of traumatic thoracic aortic injury: Clinical practice guidelines of the Society for Vascular Surgery

The Society for Vascular Surgery pursued development of clinical practice guidelines for the management of traumatic thoracic aortic injuries with thoracic endovascular aortic repair. In formulating clinical practice guidelines, the Society selected a panel of experts and conducted a systematic review and meta-analysis of the literature. They used the Grading of Recommendations Assessment, Development and Evaluation methods (GRADE) to develop and present their recommendations. The systematic review included 7768 patients from 139 studies. The mortality rate was significantly lower in patients who underwent endovascular repair, followed by open repair, and nonoperative management (9%, 19%, and 46%, respectively, < .01). Based on the overall very low quality of evidence, the committee suggests that endovascular repair of thoracic aortic transection is associated with better survival and decreased risk of spinal cord ischemia, renal injury, graft, and systemic infections compared with open repair or nonoperative management (Grade 2, Level C). The committee was also surveyed on a variety of issues that were not specifically addressed by the meta-analysis. On these select matters, the majority opinions of the committee suggest urgent repair following stabilization of other injuries, observation of minimal aortic defects, selective (vs routine) revascularization in cases of left subclavian artery coverage, and that spinal drainage is not routinely required in these cases