Abdominal Aortic Aneurysm Rupture Research Articles

Outcomes of Small Incidental Abdominal Aortic Aneurysms in Octogenarian and Nonagenarian Patients in Northern Spain

Greater population life expectancy and consistent improvement in diagnostic techniques have increased the diagnosis of abdominal aortic aneurysms (AAAs) in the elderly population. The aim was to study the natural history of small (< 55 mm) incidental AAAs in octogenarian and nonagenarian patients to assess the need for follow up and/or invasive treatment. This was a retrospective analysis of a prospective registry. Patients ≥ 80 years old at the time of diagnosis of a < 55 mm AAA in 1988-2018 were selected. Clinical and anatomical characteristics were registered. Patients were divided in three groups: 30 - 39 mm, 40 - 49 mm, and 50 - 54 mm AAA. The outcome variables were aorto-iliac rupture, AAA reaching a surgical threshold (≥ 55 mm), and death. A descriptive statistical analysis was performed and life tables, Kaplan-Meier curves, and uni- and multivariable Cox regression were used. Three hundred and ten patients were included, 256 (82.6%) men, with mean index age of 84.5 years (standard deviation [SD] 3.5), and median follow up of 37.9 months (interquartile range [IQR] 18.2 - 65.4). Eighteen (5.8%) AAAs ruptured; four of these patients were operated on and only one survived. Sixty-two (20%) AAA reached a surgical size; eight were repaired electively, with 0% early mortality. The survival rates were 81%, 70%, and 38% at one, two, and five years. The rupture rates were 1%, 2%, and 6% and the AAAs reaching surgical threshold were 1%, 4%, and 19% for the same time periods. AAA size < 40 mm was an independent protective factor from rupture (0.13; 95% confidence interval [CI] 0.03 - 0.48), reaching surgical threshold (0.08; 95% CI 0.04 - 0.16) and death (0.63; 95% CI 0.42 - 0.95). The risk of late rupture of small incidental AAA diagnosed in octogenarian and nonagenarian patients is very small, especially when the AAA is < 40 mm in diameter. In contrast, global mortality is high. Conservative management seems sensible, with strict selection of the patients who would benefit from follow up and eventual repair.

Galectin-3 as a Biomarker for Stratifying Abdominal Aortic Aneurysm Size in a Taiwanese Population.

Abdominal aortic aneurysm (AAA) ruptures are unpredictable and lethal. A biomarker predicting AAA rupture risk could help identify patients with small, screen-detected AAAs. Galectin-3 (Gal-3), a β-galactosidase–binding lectin, is involved in inflammatory processes and may be associated with AAA incidence. We investigated whether Gal-3 can be used as a biomarker of AAA size. Plasma Gal-3 protein concentrations were examined in patients with AAA (n = 151) and control patients (n = 195) using Human ProcartaPlex multiplex and simplex kits. Circulating Gal-3 levels were significantly higher in patients with AAA than in control patients. The area under the receiver operating characteristic curve for Gal-3 was 0.91. Multivariate logistic regression analysis revealed a significant association between Gal-3 level and the presence of AAA. Circulating Gal-3 levels were significantly correlated with aortic diameter in a concentration-dependent manner. In conclusion, higher plasma Gal-3 concentrations may be a useful biomarker of AAA progression.

Type 2 Endoleak With or Without Intervention and Survival After Endovascular Aneurysm Repair

The aims of the present study were to examine the impact of type 2 endoleaks (T2EL) on overall survival and to determine the need for secondary intervention after endovascular aneurysm repair (EVAR). A multicentre retrospective cohort study in the Netherlands was conducted among patients with an infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between 2007 and 2012. The primary endpoint was overall survival for patients with (T2EL+) or without (T2EL-) a T2EL. Secondary endpoints were sac growth, AAA rupture, and secondary intervention. Kaplan–Meier survival and multivariable Cox regression analysis were used. A total of 2 018 patients were included. The median follow up was 62.1 (range 0.1 – 146.2) months. No difference in overall survival was found between T2EL+ (n = 388) and T2EL- patients (n = 1630) (p = .54). The overall survival estimates at five and 10 years were 73.3%/69.4% and 45.9%/44.1% for T2EL+/T2EL- patients, respectively. Eighty-five of 388 (21.9%) T2EL+ patients underwent a secondary intervention. There was no difference in overall survival between T2EL+ patients who underwent a secondary intervention and those who were treated conservatively (p = .081). Sac growth was observed in 89 T2EL+ patients and 44/89 patients (49.4%) underwent a secondary intervention. In 41/44 cases (93.1%), sac growth was still observed after the intervention, but was left untreated. Aneurysm rupture occurred in 4/388 T2EL patients. In Cox regression analysis, higher age, ASA classification, and maximum iliac diameter were significantly associated with worse overall survival. No difference in overall survival was found between T2EL+ and T2EL- patients. Also, patients who underwent a secondary intervention did not have better survival compared with those who did not undergo a secondary intervention. This study reinforces the need for conservative treatment of an isolated T2EL and the importance of a prospective study to determine possible advantages of the intervention.

Rupture of Abdominal Aortic Aneurysm Caused by Combined Type IIIb and Type Ia Endoleak with the Endurant II Endograft: A Case Report.

We report a case of combined types IIIb and Ia endoleak that developed 6 years after endovascular aneurysm repair (EVAR) with the Endurant II® endograft for abdominal aortic aneurysm (AAA). The patient presented with post-EVAR AAA rupture and underwent emergency open repair. We observed types IIIb and Ia endoleak and successfully performed felt banding to preserve the stent graft. Type IIIb endoleak with the Endurant® endograft is rare, and treatments have not been fully established. We summarized the case reports regarding type IIIb endoleak with the Endurant® endograft and mainly discussed the treatments.

Asymptomatic Abdominal Aortic Aneurysm: Standardizing Reporting Recommendations at a Large Multistate Radiology Practice.

Although often asymptomatic at initial diagnosis, abdominal aortic aneurysms (AAAs) require careful surveillance to prevent rupture, with rupture-associated mortality rates as high as 90%. The purpose of this study was to explore if a performance improvement initiative implemented across a large radiology practice successfully increased inclusion of best practice recommendations (BPRs) within the radiology report across the practice. After BPRs for asymptomatic AAA surveillance were developed, a structured reporting macro for follow-up recommendation was integrated into dictation software. Following a training period, inclusion of recommendations within the radiology report was monitored across 345 facilities within the practice. Performance was reported on scorecards distributed monthly. To measure practice improvement, inclusion of appropriate recommendation in radiology reports postimplementation was compared with pre-implementation data. During the period before AAA BPRs implementation, from 64,090 consecutive cross-sectional radiology reports reviewed during a 6-month period, 855 incidental AAAs (1.3%) were identified, with 783 aneurysms measuring 2.6 to 5.4 cm requiring imaging surveillance; only 17 (2.1%) included follow-up recommendations within the radiology report. Postimplementation, 2,641 of 148,807 cross-sectional imaging studies were positive for 2.6- to 5.4-cm AAAs requiring further management; 1,533 (58.0%) of these radiology reports included follow-up imaging recommendations (97.0% of which followed our AAA BPRs). Quality improvement initiatives to develop BPRs for AAA surveillance and include these recommendations within the radiology report can be successfully implemented across large practices and are imperative to ensure imaging surveillance and avert AAA rupture.

Fluoroquinolones as a trigger for rupture of abdominal aortic aneurysm: A case-crossover analysis.

Fluoroquinolones (FQ) are associated with an increased risk of tendinopathy, including rupture. Our study aimed to investigate whether FQ use triggered the rupture of aortic aneurysms using a self-controlled design. We hypothesised that the use of FQ was associated with aortic rupture shortly after redeemed FQ prescriptions. Using nationwide data sources, we performed a case-crossover study of cases with ruptured aortic aneurysms. From 1996 to 2016, 58 persons presented with rupture of an aortic aneurysm and a redeemed prescription for any FQ within 28days. 67% were men, and the median age was 77years. Some 82.9% presented with a ruptured abdominal aneurysm. In our conditional regression, the crude OR for having rupture with a recent FQ redemption was 1.36 (CI 1.00-1.86). After adjusting for potential confounders, the OR was 1.35 (CI 0.98-1.85). Changing the hazard period to FQ redemption within 60 and 90days, the OR was 2.16 (CI 1.70-2.76) and 2.21 (CI 1.78-2.75), respectively. In conclusion, we demonstrated an association between FQ use within 60 and 90days and a diagnosis of ruptured aortic aneurysm.

3D Modeling of Blood Flow in Simulated Abdominal Aortic Aneurysm.

Besides biological factors, abdominal aortic aneurysm rupture is also caused by mechanical parameters, which are constantly affecting the wall's tissue due to their abnormal values. The ability to evaluate these parameters could vastly improve the clinical treatment of patients with abdominal aortic aneurysms. The objective of this study was to develop and demonstrate a methodology to analyze the fluid dynamics that cause the wall stress distribution in abdominal aortic aneurysms, using accurate 3D geometry and a realistic, nonlinear, elastic biomechanical model using a computer-aided software. The geometry of the abdominal aortic aneurysm; was constructed on a 3D scale using computer-aided software SolidWorks (Dassault Systems SolidWorksCorp., Waltham MA). Due to the complex nature of the abdominal aortic aneurysm geometry, the physiological forces and constraints acting on the abdominal aortic aneurysm wall were measured by using a simulation setup using boundary conditions and initial conditions for different studies such as finite element analysis or computational fluid dynamics. The flow pattern showed an increase velocity at the angular neck, followed by a stagnated flow inside the aneurysm sack. Furthermore, the wall shear stress analysis showed to focalized points of higher stress, the top and bottom of the aneurysm sack, where the flow collides against the wall. An increase of the viscosity showed no significant velocity changed but results in a slight increase in overall pressure and wall shear stress. Conducting computational fluid dynamics modeling of the abdominal aortic aneurysm using computer-aided software SolidWorks (Dassault Systems SolidWorksCorp., Waltham MA) proves to be an insightful approach for the clinical setting. The careful consideration of the biomechanics of the abdominal aortic aneurysm may lead to an improved, case-specific prediction of the abdominal aortic aneurysm rupture potential, which could significantly improve the clinical management of these patients.

Beware of intraperitoneal rupture during computed tomography imaging of acute aortic syndrome

The prompt diagnosis of the impending rupture of abdominal aortic aneurysms (AAAs) is imperative for rapid treatment.1 Most ruptures will manifest as retroperitoneal hematomas; intraperitoneal extravasation is rarely seen.2 It usually requires several hours from the occurrence of intramural hemorrhage to extravasation into the periaortic soft tissues.

Comparative Study of Aortic Wall Stress According to Geometric Parameters in Abdominal Aortic Aneurysms

In abdominal aortic aneurysm (AAA), the rupture of the aortic tissue is directly related to wall stress. Thus, the investigation of maximum wall stress is a necessary procedure to predict the aortic rupture in AAA. In this study, computational simulations were performed to investigate the correlation between peak wall stress (PWS) and AAA geometry. The Holzapfel model and various orientations of the collagen fibers and thicknesses of the layers of the aorta were employed in the simulation. The material constants used in the Holzapfel model were estimated from the examination and analysis of the biaxial tensile test results of the normal abdominal aorta and AAA. The aneurysm diameter, height, neck angle, and iliac angle were selected as geometric factors affecting the AAA rupture. In addition, a simulation scenario was conceived and created based on the measurement results using the computed tomography data of patients with AAA. Accordingly, the correlation between the PWS and AAA geometry was estimated.

Hemodynamic Changes in an Actively Rupturing Abdominal Aortic Aneurysm

Computational fluid dynamics were used to assess hemodynamic changes in an actively rupturing abdominal aortic aneurysm (AAA) over a 9-day period. Active migration of contrast from the lumen into the thickest region of intraluminal thrombus (ILT) was demonstrated until it ultimately breached the adventitial layer. Four days after symptom onset, there was a discrete disruption of adventitial calcium with bleb formation at the site of future rupture. Rupture occurred in a region of low wall shear stress and was associated with a marked increase in AAA diameter from 6.6 to 8.4 cm. The cross-sectional area of the flow lumen increased across all time points from 6.28 to 12.08 cm². The increase in luminal area preceded the increase in AAA diameter and was characterized by an overall deceleration in recirculation flow velocity with a coinciding increase in flow velocity penetrating the ILT. We show that there are significant hemodynamic and structural changes in the AAA flow lumen in advance of any appreciable increase in aortic diameter or rupture. The significant increase in AAA diameter with rupture suggests that AAA may actually rupture at smaller sizes than those measured on day of rupture. These findings have implications for algorithms the predict AAA rupture risk.

Inducible Depletion of Calpain-2 Mitigates Abdominal Aortic Aneurysm in Mice.

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Screening Older Adult Men for Abdominal Aortic Aneurysm: A Scoping Review.

Abdominal aortic aneurysm (AAA) is a potentially fatal condition predominantly affecting older adult men (60 years or over). Based on evidence, preventative health-care guidelines recommend screening older males for AAA using ultrasound. In attempts to reduce AAA mortality among men, screening has been utilized for early detection in some Western countries including the UK and Sweden. The current scoping review includes 19 empirical studies focusing on AAA screening in men. The findings from these studies highlight benefits and potential harms of male AAA screening. The benefits of AAA screening for men include decreased incidence of AAA rupture, decreased AAA mortality, increased effectiveness of elective AAA repair surgery, and cost-effectiveness. The potential harms of AAA screening included lack of AAA mortality reduction, negative impacts on quality of life, and inconsistent screening eligibility criteria being applied by primary care practitioners. The current scoping review findings are discussed to suggest changes to AAA screening guidelines and improve policy and practice.

Midterm single-center results after endovascular aneurysm sealing reveal a high rate of stent graft migration, secondary aneurysm ruptures, and device-related reinterventions

ObjectiveTo report procedural results and mid-term follow-up outcomes of patients treated with endovascular aneurysm sealing (EVAS) for abdominal aortic disease. MethodsIn this retrospective observational study, all patients treated with EVAS between March 2013 and January 2018 for abdominal aortic aneurysm (AAA) or abdominal penetrating aortic ulcer were included. The datasets included demographics, aneurysm morphology, and procedural and clinical surveillance outcomes. Furthermore, patients treated within the original instructions for use (IFU-group) were compared with patients treated outside the IFU (non-IFU-group) with regard to survival, reintervention-free survival, freedom from type I endoleak, and freedom from stent graft migration. ResultsSeventy patients were included (67 male; median age, 72.5 years). Sixty-five patients were treated for AAA and 5 patients for abdominal penetrating aortic ulcer. Sixty-nine cases were treated electively (98.6%). Technical success was achieved in 68 cases (97.1%). The median clinical follow-up was 50.5 months (interquartile range, 29.3-62.7 months) with a median computed tomography angiographic follow-up of 38.5 months (interquartile range, 17.1-60.2 months). There were five deaths during the study period (7.1%), four of which were aneurysm related (5.7%). Five secondary AAA ruptures were detected (7.1%). Overall, 25 of 70 patients (35.7%) underwent 35 reinterventions, mostly owing to thrombotic complications (18.6%), stent graft migration (17.1%), and type I endoleak (12.9%). Fifteen patients were treated outside of the IFU (non-IFU-group) (21.4%). The estimated reintervention-free survival for the entire cohort at 30 days and 1, 3, and 5 years was 94.3%, 88.5%, 72%, and 56.9%, respectively. Freedom from stent graft migration at 1, 3, and 5 years was 98.6%, 82.0%, and 47.3%, respectively. The estimated freedom from type I endoleak at 30 days and 1, 3, and 5 years in the IFU-group was 100%, 100%, 94.9% and, 91.1% and significantly different when compared with the non-IFU-group with 79.5%, 72.2%, 72.2%, and 72.2% (P = .012). ConclusionsAlthough the technical and initial results were satisfying, the mid-term results were disappointing. The enforcement of a close follow-up protocol for all patients treated with EVAS, especially vigilant for stent graft migration to prevent secondary type I endoleak and rupture, is strongly recommended.

Type 2 Endoleak With or Without Intervention and Survival After Endovascular Aneurysm Repair

The aims of the present study were to examine the impact of type 2 endoleaks (T2EL) on overall survival and to determine the need for secondary intervention after endovascular aneurysm repair (EVAR). A multicentre retrospective cohort study in the Netherlands was conducted among patients with an infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between 2007 and 2012. The primary endpoint was overall survival for patients with (T2EL+) or without (T2EL-) a T2EL. Secondary endpoints were sac growth, AAA rupture, and secondary intervention. Kaplan-Meier survival and multivariable Cox regression analysis were used. A total of 2 018 patients were included. The median follow up was 62.1 (range 0.1 - 146.2) months. No difference in overall survival was found between T2EL+ (n= 388) and T2EL- patients (n= 1630) (p= .54). The overall survival estimates at five and 10 years were 73.3%/69.4% and 45.9%/44.1% for T2EL+/T2EL- patients, respectively. Eighty-five of 388 (21.9%) T2EL+ patients underwent a secondary intervention. There was no difference in overall survival between T2EL+ patients who underwent a secondary intervention and those who were treated conservatively (p= .081). Sac growth was observed in 89 T2EL+ patients and 44/89 patients (49.4%) underwent a secondary intervention. In 41/44 cases (93.1%), sac growth was still observed after the intervention, but was left untreated. Aneurysm rupture occurred in 4/388 T2EL patients. In Cox regression analysis, higher age, ASA classification, and maximum iliac diameter were significantly associated with worse overall survival. No difference in overall survival was found between T2EL+ and T2EL- patients. Also, patients who underwent a secondary intervention did not have better survival compared with those who did not undergo a secondary intervention. This study reinforces the need for conservative treatment of an isolated T2EL and the importance of a prospective study to determine possible advantages of the intervention.

Characteristics and outcomes of small abdominal aortic aneurysm rupture in the American College of Surgeons National Surgical Quality Improvement Program database

ObjectiveThe current guidelines recommend elective abdominal aortic aneurysm (AAA) repair at 5.5 cm for men and 5.0 cm for women. However, rupture can occur in patients with an aneurysm smaller than these size thresholds. In the present study, we investigated the proportion of AAAs that rupture at sizes less than elective operative thresholds and compared the outcomes of repair with those of aneurysms that had ruptured at a larger size. Our hypothesis was that the rupture of small AAAs carries mortality similar to that of rupture at larger sizes. MethodsThe American College of Surgeons National Surgical Quality Improvement Program targeted vascular files for open AAA repair and endovascular aneurysm repair (EVAR) were reviewed for all cases of ruptured AAAs (rAAAs) from 2011 to 2018. The patients were divided into two groups: those with small AAAs that had ruptured at a size less than the current size guidelines for elective repair and those with large AAAs that had ruptured at a size that had met the criteria for elective repair. Univariate analyses were conducted to compare the comorbidities and perioperative outcomes of infrarenal rAAA repair between the groups. Multivariable logistic regression was performed to examine the differences in mortality between small and large rAAAs after controlling for confounding variables. ResultsOf the 1612 rAAA repairs, 167 (10.4%) were small rAAAs. The proportion of small rAAAs did not significantly change during the study period (P = .15). The large rAAA group was more likely to have juxtarenal or suprarenal aneurysms compared with the small rAAA group (27% vs 16%; P = .001). A comparison of infrarenal rAAAs only demonstrated that the mean small rAAA (n = 141) diameter was 4.1 cm in the women and 4.5 cm in the men compared with the large rAAAs (n = 1051), with a mean diameter of 7.1 cm in women and 8.3 cm in men (P < .01 for the women; P < .01 for the men). The patients in the small rAAA group had had a significantly lower body mass index but were more likely to be African American and to have hypertension. The small rAAA group was more likely to present without hypotension and to have undergone EVAR. The repair of small rAAAs was associated with lower bleeding and mortality and a shorter mean operative time but with more readmissions. Multivariable regression analysis demonstrated that size was not associated with outcome after adjusting for other variables. ConclusionsOf all AAA repairs classified as treating rupture, 10% were for patients with small AAAs. Patients with small rAAA were less likely to present with hypotension and were more likely to have undergone EVAR. Further research into sac morphology and more sensitive imaging modalities might help identify small rAAAs at high risk of rupture that would benefit from elective repair.

Society for Vascular Surgery implementation of clinical practice guidelines for patients with an abdominal aortic aneurysm: Screening for an abdominal aortic aneurysm

•High morbidity and mortality associated with abdominal aortic aneurysm (AAA) rupture.•Most effective mechanism to prevent death from rupture is the prevention of rupture itself.•Ultrasound based abdominal screening, in multiple randomized controlled clinical trials,1Cosford P.A. Leng G.C. Screening for abdominal aortic aneurysm.Cochrane Database Syst Rev. 2007; : CD002945PubMed Google Scholar associated with:○40% reduction aneurysm-related mortality○50% reduction in aneurysm rupture•AAA prevalence, growth and rupture are most strongly predicted by smoking history.•First-degree relatives of patients with AAA have approximately 20% likelihood for AAA development. Consider one-time ultrasound screening for AAA in:•Men and women aged 65 to 75 with a history of tobacco use (Grade 1A).•Men and women older than 75 in good health with history of tobacco use and not previously screened (Grade 2C).•First-degree relatives aged 65 to 75 or older than 75 in good health of patients presenting with AAA (Grade 2C).2Chaikof E.L. Dalman R.L. Eskandari M.K. Jackson B.M. Lee W.A. Mansour M.A. et al.The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm.J Vasc Surg. 2018; 67: 2-77.e2Abstract Full Text Full Text PDF PubMed Scopus (783) Google Scholar •Lower AAA prevalence in women balanced by estimated fourfold higher rupture rate and quicker progression to rupture than men (Fig).3Ulug P. Powell J.T. Sweeting M.J. Bown M.J. Thompson S.G. Group S.C. Meta-analysis of the current prevalence of screen-detected abdominal aortic aneurysm in women.Br J Surg. 2016; 103: 1097-1104Crossref PubMed Scopus (52) Google Scholar•A contemporary review estimates a 1.34% pooled prevalence of AAA in women over age 60 with a history of tobacco use, with evidence suggesting selective screening of women is cost effective beyond a threshold prevalence of 1%.2Chaikof E.L. Dalman R.L. Eskandari M.K. Jackson B.M. Lee W.A. Mansour M.A. et al.The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm.J Vasc Surg. 2018; 67: 2-77.e2Abstract Full Text Full Text PDF PubMed Scopus (783) Google Scholar,3Ulug P. Powell J.T. Sweeting M.J. Bown M.J. Thompson S.G. Group S.C. Meta-analysis of the current prevalence of screen-detected abdominal aortic aneurysm in women.Br J Surg. 2016; 103: 1097-1104Crossref PubMed Scopus (52) Google Scholar •Despite Medicare SAAAVE Act in 2007, less than 15% of eligible patients undergo AAA screening.•Consider implementing a primary care clinical alert in the electronic health record prompting an order set or mailed screening invitations for patients that meet screening criteria and include in the subsequent ultrasound report a standardized algorithm for further surveillance and management.5Hye R.J. Smith A.E. Wong G.H. Vansomphone S.S. Scott R.D. Kanter M.H. Leveraging the electronic medical record to implement an abdominal aortic aneurysm screening program.J Vasc Surg. 2014; 59: 1535-1542Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar

The Effect of Blood Transfusion during Air Medical Transport on Transport Times in Patients with Ruptured Abdominal Aortic Aneurysm

Background: Patients presenting with a diagnosis of ruptured abdominal aortic aneurysm (RAAA) to community hospitals must be transported to tertiary care centers, where necessary resources are available. Unfortunately, guidelines for treatment of RAAA lack high-level evidence on the optimal resuscitation of RAAA patients during transport. We hypothesized that transfusion of packed red blood cells (PRBCs) during transport would not delay transport times in patients with RAAA. Methods: We performed a retrospective analysis of a prospective registry including prehospital data of patients with RAAA presenting to a single academic hospital in Western Pennsylvania between 2001 and 2019. Our primary outcomes were prehospital transport times: “transport interval” and “total interval.” “Transport interval” is the duration from patient pickup at the outside hospital (OSH) to arrival at the receiving facility. “Total interval” is the duration from dispatch of the air medical transport to arrival of the patient to the receiving facility. We then compared two groups of patients, stratified by the receipt of PRBCs in transit, by reporting mean difference (95% confidence interval: CI) for continuous variables and percent difference (95% CI) for categorical variables. We performed two multivariate linear regression models to test if there was any effect of the receipt of PRBCs in transit on transport times. Results: We included 271 patients with RAAA transported by our air ambulance system who underwent an operation at the receiving facility, 99 (37%) of whom received PRBCs in transit. Mean ± standard deviation (SD) of the total intervals were 67 ± 28 and 71 ± 42 minutes, among patients who received or did not receive PRBCs in transit respectively, with no significant difference (p = 0.437). Following adjusted analysis, the receipt of PRBCs during transport was not associated with increased transport times, after accounting for age, hypotension, endovascular aneurysm repair (EVAR), and PRBC transfusion at the OSH. Conclusion: PRBC transfusion during air medical transport in patients with RAAA did not delay transport times.

Epidemiology of endovascular and open repair for abdominal aortic aneurysms in the United States from 2004 to 2015 and implications for screening

BackgroundContemporary national trends in the repair of ruptured abdominal aortic aneurysms (AAAs) and intact AAAs are relatively unknown. Furthermore, screening is only covered by insurance for patients aged 65 to 75 years with a family history of AAAs and for men with a positive smoking history. It is unclear what proportion of patients who present with a ruptured AAA would have been candidates for screening. MethodsUsing the National Inpatient Sample from 2004 to 2015, we identified ruptured and intact AAA admissions and repairs using the International Classification of Diseases codes. We generated the screening-eligible cohort using previously identified proportions of male smokers (87%) and all patients with a family history of AAAs (10%) and applied these proportions to patients aged 65 to 75 years. We accounted for those who could have had a previous AAA diagnosis (17%), either from screening or an incidental detection in patients aged >75 years who had presented with AAA rupture. The primary outcomes were treatment and in-hospital mortality between patients meeting the criteria for screening vs those who did not. ResultsWe evaluated 65,125 admissions for ruptured AAAs and 461,191 repairs for intact AAAs. Overall, an estimated 45,037 admitted patients (68%) and 25,777 patients who had undergone repair for ruptured AAAs (59%) did not meet the criteria for screening. Of the patients who did not qualify, 27,653 (63%) were aged >75 years, 10,603 (24%) were aged <65 years, and 16,103 (36%) were women. Endovascular AAA repair (EVAR) increased for ruptured AAAs from 10% in 2004 to 55% in 2015 (P < .001), with operative mortality of 35%. EVAR increased for intact AAAs from 45% in 2004 to 83% in 2015 (P < .001), with operative mortality of 2.0%. ConclusionsMost patients who had undergone repair for ruptured AAAs did not qualify for screening. EVAR was the primary treatment of both ruptured and intact AAAs with relatively low in-hospital mortality. Therefore, expansion of the screening criteria to include selected women and a wider age range should be considered.

Epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) disease remains a major source of morbidity in developed countries and can progress to life-threatening rupture if left untreated, with exceedingly high mortality. The goal of AAA management is to identify and electively repair AAAs before rupture. AAA disease burden and outcomes have improved over time with declining tobacco use and advancements in care across patients’ disease course. The introduction of endovascular AAA repair, in particular, has allowed for elective AAA repair in patients previously considered too high risk for open surgery and has contributed to lower rates of AAA rupture over time. However, these improved outcomes are not universally experienced, and disparities continue to exist in the detection, treatment, and outcomes of AAA by sex, race, and ethnicity. Mitigating these disparities requires enhanced, focused efforts at preventing disease, promoting health, and delivering appropriate care among an increasingly diverse patient population.

Coupled Hemodynamics and Oxygen Diffusion in Abdominal Aortic Aneurysm: A Computational Sensitivity Study.

Abdominal Aortic Aneurysms (AAA) have extreme medical prevalence as an asymptomatic cause of death in developed countries. The probability of AAA rupture is promoted by the localized oxygen loss in the AAA wall which occurs in part because many AAAs contain a layer called intraluminal thrombus (ILT). Considering this strong clinical association, the purpose of this study is to investigate the key features that constitute to the oxygen diffusion, and therefore hypoxia in AAA. A three-dimensional model of AAA containing ILT is created and numerical simulations are performed to simulate blood flow and oxygen distribution within the AAA. The model accounts for blood flow in the lumen and oxygen transport in the lumen, ILT, and arterial wall. The sub-model of the ILT is fully coupled with the wall sub-model as well as with the subdomain of the blood flow. The sensitivity of the oxygen flow with respect to the parameters of the problem is also analyzed. Model simulations are used to investigate the relation between AAA physical properties, hemodynamics, and oxygen concentration in different geometries of AAA. The results demonstrate that the diameter of the AAA bulge has little effect on the oxygen flow, but that the thickness of the ILT layer has a profound effect. Moreover, a significant sensitivity to the oxygen supply from vasa vasorum and its notable impact on oxygen transport within AAA are observed. The variability of the arterial wall oxygen concentration to the oxygen reaction rate remains however very low. The presence of an ILT significantly impairs oxygen transport from the lumen to the wall. This study confirms that consideration of ILT size and anatomy may be important in considering the severity of a AAA, however, other parameters can also affect thrombus-mediated oxygen delivery within the aneurysmal wall.