Nonruptured Abdominal Aortic Aneurysm Research Articles

Impact of hospital market competition on endovascular aneurysm repair adoption and outcomes

The share of total abdominal aortic aneurysm (AAA) repairs performed by endovascular aneurysm repair (EVAR) increased rapidly from 32% in 2001 to 65% in 2006 with considerable variation between states. We hypothesized that hospitals in competitive markets were early EVAR adopters and had improved AAA repair outcomes. Nationwide Inpatient Sample and linked Hospital Market Structure (HMS) data was queried for patients who underwent repair for nonruptured AAA in 2003. In HMS, the Herfindahl Hirschman Index (HHI, range 0-1) is a validated and widely accepted economic measure of competition. Hospital markets were defined using a variable geographic radius that encompassed 90% of discharged patients. We conducted bivariate and multivariable linear and logistic regression analyses for the dependent variable of EVAR use. A propensity score-adjusted multivariable logistic regression model was used to control for treatment bias in the assessment of competition on AAA repair outcomes. A weighted total of 21,600 patients was included in our analyses. Patients at more competitive hospitals (lower HHI) were at increased odds of undergoing EVAR vs open repair (odds ratio, 1.127 per 0.1 decrease in HHI; P < .0127) after adjusting for patient demographics, comorbidities, and hospital level factors (bed size, teaching status, AAA repair volume, and ownership). Competition was not associated with differences in in-hospital mortality or vascular, neurologic, or other minor postoperative complications. Greater hospital competition is significantly associated with increased EVAR adoption at a time when diffusion of this technology passed its tipping point. Hospital competition does not influence post-AAA repair outcomes. These results suggest that adoption of novel vascular technology is not solely driven by clinical indications but may also be influenced by market forces.

Diabetes mellitus is not associated with major morbidity following open abdominal aortic aneurysm repair

BackgroundIt has been suggested that there is an increased morbidity and mortality risk for diabetics undergoing elective aortic surgery. This, however, is not universally accepted. In this study, we utilize a national database to determine if diabetes is associated with adverse outcomes following open, elective, infrarenal abdominal aortic aneurysm (AAA) repair. MethodsThe American College of Surgeons’ National Surgical Quality Improvement Program database was queried to identify all patients who underwent an open, elective, nonruptured AAA repair from January 1, 2005 to December 31, 2007. Patient demographics, comorbidities, and outcomes were compared by diabetes status. Multivariate analysis was performed adjusting for demographics and comorbidities. ResultsThere were 2110 American College of Surgeons’ National Surgical Quality Improvement Program patients who underwent an open, elective, nonruptured AAA repair during this time period. Of these patients, 245 (11.6%) had diabetes mellitus. The overall mortality rate was 3.7% (5.3% for diabetics and 3.5% for nondiabetics, P = 0.171).On bivariate analysis, diabetics were more likely to present preoperatively with cardiovascular and renal comorbidities. Postoperatively, there was no significant difference in mortality or in cardiac, pulmonary, or renal complications. Diabetics were more likely to develop superficial surgical site infections (SSIs) (4.5% versus 1.6%, P = 0.002).On multivariate regression, there was no difference in mortality or major complications between diabetics and nondiabetics (OR 1.4, 95% CI 0.68–2.71). Diabetics, however, were almost three times more likely to develop superficial SSIs (OR 2.8, 95% CI 1.29–6.00). ConclusionsDiabetes mellitus is not associated with significantly worse major outcomes following open, elective, infrarenal AAA repair. Diabetics, however, are more likely to develop superficial SSIs.

Abstract 223: Is Oxidative Stress Important in AAA pathogenesis?

OBJECTIVE Active investigations continue to identify markers other than size that would predict a risk of abdominal aortic aneurysms (AAA) rupture. Circulating biomarkers could also indicate optimal intervals between the surveillance intervals. Finally, the identification of biomarkers also may identify potential pathogenic pathways, and thus may open possibilities for pharmacological inhibition of growth. In the search of novel biomarkers of AAA progression, serum and wall material proteins were analyzed by a differential proteomic approach. METHODS AND RESULTS The same layers of AAA wall from ruptured (rAAA) and non-ruptured AAA were incubated, and the proteins released were analyzed by 2-dimensional difference in-gel electrophoresis. Proteins from serum were analyzed and correlated with AAA annual expansion rate. Several differentially expressed proteins involved in main AAA pathological mechanisms were identified by mass spectrometry. Among the 8 proteins identified in AAA wall, peroxiredoxin-2 (PRX-2) was more permanent, which was further validated by Western blot and immunohistochemistry. We demonstrated increased PRX-2 levels in rAAA patient wall material compared with AAA subjects and also positive correlation in serum among PRX-2 and AAA diameter and annual AAA expansion rate. CONCLUSIONS Eight proteins associated with AAA pathogenesis have been identified in AAA wall by a proteomic approach. Protein profiles identified in the wall from the rAAA and the serum would appear to be a convenient monitoring tool that has the ability to be both sensitive and specific for AAAs. Among them, PRX-2 serum levels are increased in AAA patients and correlate with AAA size and growth rate, suggesting the potential use of PRX-2 as a biomarker for AAA evolution. Characterizing such diagnostic protein profiles, combined with known risk factors as well as emerging genetic data, would contribute to the long-term objective of applying effective non-surgical therapies to the treatment of small AAA disease. Larger studies are required to confirm the potential and clinical role of the identified proteins.

Abstract 284: microRNAs are Novel Plasma Biomarkers for Diagnosis and Prognosis of Abdominal Aortic Aneurysm Disease

MicroRNAs (miRNAs) have been identified as transcriptional and posttranscriptional inhibitors of gene expression, thought to “fine tune” the translational output of their target mRNAs. Recently, they have received much attention regarding their suitability as biomarkers for disease. Our goal was to explore the diagnostic and prognostic value of miRNAs in abdominal aortic aneurysms (AAAs), a disease for which currently no established biomarker exists. Using a PCR-based array platform, we profiled the 168 most abundant blood miRNAs in 20 patient plasma samples with AAA disease, undergoing surgical repair of their enlarged aorta vs. 20 samples from an age, risk factor, and medication matched control group without aneurysm. We were able to identify a total number of 12 miRNAs being significantly altered in diseased patient samples as compared to controls. We further investigated these 12 miRNAs in plasma (as well as in aortic tissue) from apoE-/- mice with angiotensinII (AngII)-infusion induced AAAs, enabling us to discover a potential prognostic value of miRNAs being released into circulation. Indeed we were able to detect that the expression of 4 out of the 12 miRNAs (miRs-126 and -668 both increased; miRs-24 and -210 both decreased), was substantially modified in plasma samples drawn from mice with AAA immediately before rupture occurred between days 10 and 14 after AngII pump implantation compared to mice with AAA that did not rupture for the remainder of study (28 days), as well as saline-infused controls. Importantly, the expression of miRs-24 and -126 appeared also significantly different in plasma samples from patients with ruptured AAAs (n=7) compared to patients with non-ruptured AAAs (abdominal aortic diameter between 55-78 mm; n=7) and un-diseased controls (n=7). The present study explores the diagnostic and prognostic biomarker potential of miRNAs being released into circulation during initiation, propagation, and ultimately rupture of AAA disease in mice and humans. The identification of miRs-24, -126, -210, and -663 potentially offers great prognostic value to determine which patients present with an increased risk of AAA rupture.

PCV48 - A model utilizing preoperative markers to predict patients associated with high cost in open versus endovascular repair of non-ruptured abdominal aortic aneurysm

PCV48 - A model utilizing preoperative markers to predict patients associated with high cost in open versus endovascular repair of non-ruptured abdominal aortic aneurysm

Perioperative Haemorrhage in Endovascular Abdominal Aneurysm Repair Affects Outcome

This study aimed to evaluate the outcome and predisposing factors related to perioperative bleeding in patients treated with endovascular aneurysm repair (EVAR) for ruptured and non-ruptured abdominal aortic aneurysm (AAA). This was a retrospective cohort study. A total of 525 consecutive patients (73% elective) with AAA underwent EVAR at two vascular centres from 2008 to 2011. From registry data perioperative bleeding was analysed in relation to outcome and preoperative data. A total of 453 (86%) patients presented with a perioperative bleeding <1000 ml, 42 (8%) patients 1000-1999 ml, 19 (4%) patients 2000-5000 ml and 11 (2%) >5000 ml. Other than ruptured AAA (n = 90), no preoperative risk factors for increased perioperative bleeding were found. Open femoral artery access (n = 101), branched (n = 18) and uni-iliacal endografts (n = 18) and introducer size were associated with increased perioperative bleeding (P < 0.001). In multivariable logistic regression only rupture and perioperative bleeding >2000 ml were significantly related to 30-day mortality (odds ratio 10.6 (range 3.8-29.6) and 13.4 (range 4.8-37.4), respectively). Postoperative renal failure, multi-organ failure, >5 days at intensive care unit, bowel ischaemia and abdominal compartments syndrome were significantly related to perioperative bleeding >2000 ml (P < 0.001). Large perioperative bleeding during EVAR is a clinical problem that affects outcome. About 10% of elective AAA patients and 34% of patients with ruptured AAA, undergoing EVAR, present a perioperative blood loss exceeding 1 l. In our study, a perioperative blood loss exceeding 2 l was independently associated with increased mortality and morbidity in both acute and elective AAA patients. Open femoral access, branched EVAR and larger diameter introducers were associated with increased perioperative blood loss. ETHICAL APPLICATION: 2011/664-31/3 (approved).

Management of symptomatic abdominal aortic aneurysms following emergency computed tomography

It is still difficult to determine the appropriate timing of surgery for a symptomatic abdominal aortic aneurysm (AAA). Since recent developments in computed tomography (CT) have made the procedure substantially less time-consuming, we used CT on patients with symptomatic AAA to determine the most appropriate management option. CT was performed on 79 patients with symptomatic AAA. If rupture of the AAA was confirmed by CT, patients underwent emergency surgery. If there was no rupture, patients were observed in an intensive care unit, and surgery was scheduled according to the results of repeated CT (2.1 times on average) and physical examinations, as well as on their clinical signs and symptoms. By CT, we identified 42 ruptures, one contained rupture, one aortocaval fistula, five acute aortic dissections with AAAs, six inflammatory AAAs, six pseudoaneurysms and 18 non-ruptured AAAs. The mortality rate of the patients with ruptures was 33%. For the 37 patients without rupture, as determined by CT, three emergency, nine urgent, and 20 elective operations were performed. Two patients who refused surgery experienced late rupture and died. Among the other 35 patients, the mortality rate was 6%. CT was an effective modality to classify patients with symptomatic AAA into those who needed emergency surgery and those who did not. We could observe patients with symptomatic non-ruptured AAAs before urgent/elective operations by repeated CT and monitor the clinical findings.

The Impact of Blood Component Transfusion Practices on Patient Survival After Abdominal Aortic Aneurysm Surgery

The aim of the present study was to investigate the blood transfusion practice in patients operated for abdominal aortic aneurysm (AAA) with special emphasis on massive transfusion in cases with rupture. From a database, 504 patients operated for AAA were stratified into 2 groups; an early transfusion period (1992-1999) and a late transfusion period (2000-2008) to evaluate the changes in transfusion practices over the course of time. Patients operated for nonruptured AAA (n = 330) showed a decreased mortality rate from 4% (early transfusion period) to 1% (late transfusion period) without significant changes in the transfusion practices. In patients operated for ruptured AAA (n = 174) an unexpected low mortality rate was found compared to the 30-day mortality reported in earlier studies. The transfusion practices in ruptured AAA surgery showed a significant increase in platelet use and change of fresh frozen plasma: red blood cell ratio from 0.8 to 0.9 between the early and the late transfusion period. The present database study shows that the operating mortality for AAA surgery has declined during the past decades. The cause of the decline in mortality in patients with ruptured AAA was interpreted as partly due to a modern blood component therapy.

Abstract 9893: Preoperative Lower Cholesterol Level is the Independent Risk Factor of Severe Postoperative Mortality in Patients With Ruptured Abdominal Aortic Aneurysm

Background: Hypocholesterolemia is reported to be the critical risks of hemorrhagic stroke, but the influence of hypocholesterolemia on large vessels such as abdominal aortic aneurysm (AAA) is unknown. Methods: We conducted a retrospective cohort study on 1053 consecutive patients receiving the surgical repair for infrarenal AAA in multicenter in Tokyo from 2003 through 2011. Laboratory data including total cholesterol levels were measured immediately before surgery. Cox hazards model were used to evaluate the risk factors for the postoperative mortality as well as major adverse cardiac events (MACE; composite of cardiovascular death without postoperative in-hospital death, acute coronary syndrome, cerebrovascular disorder). Results: The average follow-up period was 2.5 ± 2.1 years. In the multiple Cox analysis adjusted for age, gender, aneurysm size, smoking, hypertension, diabetes, past history of coronary disease, past history of chronic obstructive pulmonary disease, anemia, shock, statin use, β-blocker use and angiotensin II receptor blocker use, anemia (hemoglobin level &lt; 10 g/dl), shock and hypocholesterolemia (total cholesterol level &lt; 120 mg/dl) before surgery were found to be the risk factors of all postoperative death in patients with ruptured AAA (HR3.3; 95%CI 2.0-5.3, HR2.5; 95%CI 2.0-4.7, HR;5.4 CI 3.0-9.7, respectively, n=183). Meanwhile, there found to be no risk factor of all death in non-ruptured AAA (n=870). Furthermore, the mortality of patients with each total cholesterol level 120 - 140, 140 - 160, and 160 - 180 mg/dl was higher than that of total cholesterol level &gt; 180 mg/dl (HR3.2; 95%CI 1.9-5.2, HR2.7; 95%CI 1.6-4.4, HR1.8; 95%CI 1.0-3.2, respectively). Receiver operator characteristic (ROC) curve analysis showed hypocholesterolemia is the most significant predictor of postoperative in-hospital death in patients with ruptured AAA (the area under the ROC curve = 0.77). The risk factor of MACE was identified to be the existence of preoperative coronary artery disease. Conclusions: The risk factors of poor mortality in patients with ruptured AAA were anemia, shock and hypocholesterolemia. The lower total cholesterol level indicated the more severe mortality of ruptured AAA.

Trends in the utilization of endovascular therapy for elective and ruptured abdominal aortic aneurysm procedures in Canada

While randomized trials have shown improved operative mortality with endovascular aneurysm repair (EVAR) but similar long-term mortality rates, enthusiasm for EVAR persists, and rates of EVAR use continue to increase. Currently, knowledge of utilization rates of EVAR in Canada is limited. Patients who underwent nonruptured abdominal aortic aneurysm (AAA) and ruptured AAA (RAAA) repair, by either open surgical repair (OSR) or EVAR, in Canada were identified from hospital discharge abstract data. Trends in rates for OSR and EVAR were calculated by province and by year, and standardized per 100,000 persons over 65 years of age (per capita). Between April 2004 and March 2009, 15,960 AAA procedures were performed in Canada, either by OSR (n=12,204) or EVAR (n=3756). The proportion of all elective AAA procedures by EVAR increased from 11.5% in 2005 to 35.5% in 2009, the highest current proportion of EVAR utilization in British Columbia (45.0%) and the lowest in Manitoba (15.8%). After standardization, the national rate of total procedures was steady, but the rate of RAAAs declined over the entire study period. Alberta consistently had the highest per capita rates of EVAR use (38.9), whereas Prince Edward Island had the lowest (8.4). Provincial variations in EVAR use did not correlate with differences in comorbidities. Compared with Canadian averages, Atlantic Provinces performed the most AAA procedures per capita (137.5 vs 93.4), had the highest rate of RAAAs per capita (29.7 vs 22.2), and had the lowest proportional rates of EVAR use. Use of EVAR in Canada for AAAs has increased in the past 5 years, without affecting overall AAA procedure volumes. Large discrepancies in EVAR use exist across Canada. The Atlantic Provinces had the highest rates of RAAAs despite having the highest rates for total AAA procedures, suggesting a population with higher susceptibility for AAAs. This region may also have the largest potential for future increased use of EVAR.

Comparison of Long-term Survival After Open vs Endovascular Repair of Intact Abdominal Aortic Aneurysm Among Medicare Beneficiaries

Conclusion: In Medicare beneficiaries, repair of isolated, intact abdominal aortic aneurysms (AAA) by endovascular means is associated with a lower risk of all-cause mortality and AAA-related mortality than repair using open techniques. Summary: Randomized clinical trials (RCTs) have failed to demonstrate a long-term survival advantage of endovascular repair vs open repair of AAA. Furthermore, a previous study of Medicare beneficiaries undergoing AAA repair between 2001 and 2004 also failed to demonstrate a survival advantage of endovascular repair over open repair beyond 3 years of follow-up (Schemerhorn ML et al, N Engl J Med 2008;358:464-74). It is possible current endovascular devices may provide improved overall results of endovascular repair than those available for analysis of endovascular vs open AAA repair in the previous study of Medicare beneficiaries. The authors, therefore, decided to compare overall and AAA-specific mortality, readmission, and reintervention after endovascular vs open repair of nonruptured AAAs in Medicare beneficiary patients using a database from 2003 to 2007. This was a retrospective analysis of patients aged ≥65 years in the Medicare standard analytic file, 2003 to 2007, who underwent isolated repair of an intact AAA. The national death index was used to determine cause of death. Primary outcome was all-cause mortality. Secondary outcomes were AAA-related mortality, hospital length of stay, 1-year readmission, repeat AAA repair, incisional hernia repair, and lower extremity amputation. The Medicare standard analytic files contained data from a 5% example of Medicare inpatient discharges. The study included 4029 patients; of these, 703 underwent open repair and 3826 underwent endovascular repair. Mean and median follow-up times were 2.6 (SD, 1.5) and 2.5 (interquartile range, 2.4) years, respectively. After adjusting for emergency admission, age, calendar year, sex, race, and comorbidities, there was a higher risk of both all-cause mortality (hazard ratio, 1.24; 95% confidence interval [CI], 1.05-1.47; P = .01) and AAA-related mortality after open vs endovascular repair (hazard ratio, 4.37l; 95% CI, 2.51-7.66; P < .001). Adjusted hospital length of stay averaged 6.5 days (95% CI, 6.0-7.0 days; P < .001) longer after open repair (mean, 10.4 days) compared with endovascular repair (mean, 3.6 days). Need for incisional hernia repair was higher after open AAA (P < .001). The 1-year readmission rates, repeat AAA repair, and lower extremity amputation did not differ by repair type. Comment: The data presented here do not demonstrate inferiority of endovascular vs open AAA repair. However, there are really too many deficiencies in the data to justify a conclusion that the data demonstrate superiority of endovascular vs open repair of AAAs. First, follow-up is relatively short and the number of patients analyzed quite small compared with the number potentially available for analysis. In addition, the Medicare database does not contain information about aneurysm configuration and other anatomic factors that may influence surgeon choice of endovascular or open repair. Given the general acceptance of endovascular repair, it is quite likely many—if not most—of the patients undergoing open repair were judged not suitable for endovascular repair. The report compares survival after open or endovascular repair but not necessarily in patients suitable for either open or endovascular repair. The report does not adequately address reinterventions. Most patients undergo reinterventions for failure of endovascular repair as outpatients, which was not analyzed in this study, and reinterventions for open and endovascular aneurysm graft-related failure requiring readmission tend to occur beyond the median follow-up of this report (Kelso RL et al, J Vasc Surg 2009;49:589-95; and Brinster CJ et al, J Vasc Surg 2011;54:42-6). The most reasonable conclusion provided by the data is that endovascular repair as a form of management of AAA is a reasonable approach for management of anatomically suitable patients with AAA who are Medicare beneficiaries. The data are not suitable for cost-analysis or analysis of all relevant reinterventions.

Long-term follow-up of endovascular abdominal aortic aneurysm repair in a rural veteran patient population

BackgroundThe endovascular repair of abdominal aortic aneurysms (EVARs) requires follow-up to detect and treat late complications. MethodsTwo hundred eleven patients underwent EVAR for infrarenal, nonruptured abdominal aortic aneurysms from 1999 to 2010 at the Raymond G. Murphy VA Medical Center, Albuquerque, NM. A retrospective review examined patient demographics, comorbidities, the distance the patient lived from the facility, early and late complications, and the device implanted. Statistical analysis included the chi-square test for independence, the Fisher exact test, and the 2-sample Mann-Whitney U test for means. ResultsThe mean time from the operation to the first complication was 21 months (standard deviation = 20 months) with a mean follow-up of 48 months (standard deviation = 36 months). The late complication rate was 22.8% (54 patients). Sixteen percent did not require any reinterventions, 57% were treated with percutaneous interventions, and 27% required an open surgical procedure. No single comorbidity, combination of comorbidities, distance the patient lived from the facility, or device implanted was predictive of complications. ConclusionsEVAR follow-up is essential to detect complications. When complications occur, the majority occur well after the initial treatment, and most can be treated with minimally invasive percutaneous techniques.

ABO blood groups and abdominal aortic aneurysm

Earlier studies have indicated an association between blood group non-O and atherosclerosis related vascular diseases. Abdominal aortic aneurysm (AAA) is traditionally regarded as a consequence of atherosclerosis. The aim of the present study was to investigate the association between ABO blood groups and AAA with special regard to a relation to AAA rupture. Prospectively, 504 patients operated on for AAA were investigated. Patients operated on for AAA have similar ABO blood group distributions as a population based control group. Furthermore, there was no significant difference in distribution of ABO blood group between patients operated on for ruptured AAA (n=174) and non-ruptured AAA (n=330). In conclusion, this study fails to demonstrate an association between ABO blood groups and AAA.

Soluble urokinase plasminogen activator receptor in patients with abdominal aortic aneurysm

IntroductionIn the present study we investigated the impact of soluble urokinase plasminogen activator receptor (suPAR) as a biomarker in patients with abdominal aortic aneurysm (AAA) in relation to conventional inflammatory markers, aneurysm size, and rupture. MethodssuPAR and conventional inflammatory markers were measured in 119 patients with AAA and 36 controls without aneurysm matched by age, gender and smoking habit. ResultsThe results support earlier studies suggesting a state of activated inflammatory response in patients with nonruptured AAA as expressed by elevated CRP and IL-6 compared with the controls. In contrast, suPAR showed similar levels in patients with nonruptured AAA compared with the controls. Unexpectedly, all follow-up patients (n=16) have significant (p<0.001) elevated suPAR levels three years postoperatively compared preoperatively. ConclusionssuPAR does not seem to be a useful biomarker in the AAA disease. The role of the postoperative elevation of suPAR needs to be further elucidated.

PS30. Changing Trend of Mortality Rate from Ruptured and Non-ruptured Abdominal Aortic Aneurysm in Last Three Decades in the USA

rAAA and uAAA was different. SVM correctly classified more uAAA (81% vs. 78% for kNN) while kNN classified more rAAA (87% vs 83% for SVM). Using the standard maximum diameter of 5.5 cm, 31.1% of the AAAs would have been misclassified (20 ruptured and 36 unruptured). The ruptured and unruptured AAA features tended to group together, with the most predictive features forming clusters. The ten most predictive features, given by the 2 test, were: skewness of Gaussian curvature distribution, tortuosity, non-fusiform index, minimum Mean curvature, L2 norm of Mean curvature, wall surface area, L2 norm of Gaussian curvature, isoperimetric ratio, length, and the maximum diameter. Conclusions: SVM and kNN classified more AAA correctly than a maximum diameter of 5.5 cm, indicating that maximum diameter alone is not sufficient for predicting AAA rupture risk compared to a robust geometry quantification approach.

Changing Epidemiology of Abdominal Aortic Aneurysms in England and Wales

Background— Recent studies from Australia, New Zealand, and Sweden have reported declines in abdominal aortic aneurysm (AAA) incidence, prevalence, and mortality. This finding may have important implications for screening programs. This study determined trends in AAA incidence and mortality in England and Wales. Methods and Results— Cause-specific mortality data for England and Wales were obtained from UK Office for National Statistics, and hospital admissions and procedures data for England were obtained from Hospital Episode Statistics from 2001 to 2009. Poisson regression models were constructed to estimate the relative change over time. Age-standardized rates for AAA mortality in England and Wales fell significantly by 35.7% from 2001 to 2009, which was largely due to a 35.3% drop in age-standardized ruptured AAA deaths. During the same period, ruptured AAA admissions and emergency AAA repairs in England declined by 29.3% and 35.5%, respectively. In contrast, nonruptured AAA admissions remained static, and nonemergency AAA repairs increased by 17.2%. The average ages for hospital admissions for nonruptured AAAs and ruptured AAAs increased by 0.19 years of age per annum ( P &lt;0.001) and 0.09 years of age per annum ( P &lt;0.001), respectively. Nonruptured AAA admissions increased by 21.4% in age band 75 years or more but declined by 11.7% in ages &lt;75 years. Conclusions— AAA mortality, ruptured AAA admission, and emergency AAA repair have declined in England and Wales. However, nonruptured AAA admission has remained steady, with an increasing rate in older population offsetting a decreasing rate in younger population. This suggests a shift in AAA presentation to the older population. Present screening strategies may need reassessment to include consideration for increasing the age at which to screen men for AAAs.

Minimal incision approach for abdominal aortic aneurysm (AAA) repair

To evaluate the appropriate use of the minimal incision aortic surgery (MIAS) approach in nonruptured infrarenal abdominal aortic aneurysm (AAA) repair, we prospectively compared the MIAS approach with the transperitoneal approach (TPA). Eighteen patients in whom the MIAS was used and 18 who had the TPA during the same period were included in this study. There was a significant difference in intraoperative fluid needs (2050 ± 510, MIAS; 3500 ± 300, TPA) and estimated blood loss (ml) (855 ± 316, MIAS; 1246 ± 615, TPA) between the two groups. The MIAS approach had a shorter intensive care unit (ICU) stay (1 d vs. 2.4 d), hospital stay (8.3 d vs. 14.5 d), quicker return to general dietary feeding (2 d vs. 6.9 d), and less morbidity (23.5% vs. 77.7%) than the TPA group. The MIAS group had a smaller total cost payment than the TPA group (US$ 3,000 ± 150 vs. US$ 3,750 ± 200) because of less complications, shorter ICU, and shorter hospital stay. Our findings indicated that MIAS is a safe, effective, and suitable method for nonruptured infrarenal AAA repair.

Transverse minilaparotomy for open abdominal aortic aneurysm repair

Traditional open surgical repair for abdominal aortic aneurysm (AAA) is a major procedure with a relatively high risk of perioperative morbidity. This article describes the results of minimally invasive open AAA repair through a transverse left upper quadrant minilaparotomy. Between January 2007 and June 2010, 83 consecutive patients (77 men) underwent elective or urgent repair of a nonruptured AAA through a horizontal transperitoneal left upper quadrant minilaparotomy. Postoperatively, patients were fast-tracked through a multidisciplinary recovery program. Repairs were urgent in 15 patients (18%), and 10 (12%) had aortoiliac aneurysms. American Society of Anesthesiologists (ASA) scores 1 to 4 were 3.6%, 44.6%, 42%, and 11%, respectively. Median (range) age was 73 (61-87) years, AAA size was 5.9 (5.1-10) cm, body mass index was 27 (19-39) kg/m(2), operation time was 150 (85-280) minutes, blood loss was 625 (200-4150) mL, critical care bed days was 1 (0-19), and hospital stay was 4 (2-88) days. Four (4.8%) patients returned to the operating theater within the same admission. No patients required conversion to full laparotomy and none had reintervention postdischarge. Two patients (2.4%) died in the hospital, and 18 (21.7%) had postoperative adverse events, ranging from urinary retention to myocardial infarction. New-onset atrial fibrillation was the commonest of these events (11, 13.3%). Respiratory tract infection incidence was low (4.8%). Incisional herniation developed in two patients (2.4%) at a median (range) follow-up of 10 (6-25) months. Correcting for age, cardiac complications were associated with increased odds of hospital stay >4 days (odds ratio [OR], 7.59; 95% confidence interval [CI], 1.12-52.42; P = .014). Correcting for ASA score, advancing age was associated with increased risk of cardiac complications (OR, 1.18; 95% CI, 1.08-1.28; P = .001), whereas AAA screening (patient identified through screening) and maintaining higher intraoperative systolic pressure were both protective (OR, 0.24; 95% CI, 0.07-0.87; P = .018) and (OR, 0.93; 95% CI, 0.89-0.98; P = .009), respectively. Left upper quadrant minilaparotomy is a feasible minimally invasive approach to open AAA repair. This technique is associated with low morbidity and mortality and short hospital stay, particularly in patients identified through AAA screening.

Falling rates of hospitalization and mortality from abdominal aortic aneurysms in Australia

Studies of the population trends for abdominal aortic aneurysms (AAAs) in the period 1970 to 2000 all indicated that the incidence of AAAs was increasing. It is not known whether this increase has continued. We hypothesized that the incidence of AAAs has begun to fall in Australia. Age-standardized national trends in mortality from AAAs were estimated for the period 1999 to 2006, and hospital separations (deaths or discharges) for AAAs were estimated for the period 1999 to 2008. Poisson regression models were constructed to estimate the relative change over time. The age-standardized mortality rate from AAAs fell by an average of 6.0% (95% confidence interval [CI], 4.7-7.3) per annum in men and 2.9% (95% CI, 1.0-4.7) in women. After adjusting for age, hospital separations for men decreased by an average of 2.3% (95% CI, 1.4-2.7) per annum for nonruptured AAAs, and 5.9% (95% CI, 5.0-6.6) for ruptured AAAs and for women decreased by an average of 2.2% (95% CI, 1.4-3.0) per annum for nonruptured AAAs, and 5.1% (95% CI, 3.7-6.5) for ruptured AAAs. Ruptured, compared with nonruptured, AAAs were proportionally more common in women compared with men. The age-specific trends in separations from hospital were all downward apart from nonruptured AAAs in individuals aged 80 years and over. The rates of separation from hospital and mortality for AAAs in Australia have fallen since 1999. This suggests a true fall in incidence of AAAs. Although the reasons for this are unknown, it has implications for policy decisions about screening.

Proteins associated with the size and expansion rate of the abdominal aortic aneurysm wall as identified by proteomic analysis☆

Identification of biomarkers for the natural history of abdominal aortic aneurysms (AAA) holds the key to non-surgical intervention and improved selection for AAA repair. We aimed to associate the basic proteomic composition of AAA wall tissue with the expansion rate and size in patients with AAA. A proteomic approach was used, consisting of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS) to identify differentially expressed proteins in AAA tissue. Relevant protein spots were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Spearman's correlation analysis revealed 16 protein spots were strongly correlated with AAA expansion rate (ρ>±0.75). Nine protein spots were identified. Six protein spots showed correlation with AAA size (ρ>±0.5). Three protein spots were identified: vitronectin with traces of calreticulin, albumin and a spot containing two proteins: collagen α-3(VI) chain and vitamin D binding protein. Interestingly, in our previous study vitronectin was shown to be down-regulated in a ruptured AAA group compared with non-ruptured AAA. Western blot analysis in the present study confirmed a correlation of vitronectin bands with AAA size in aortic aneurysm tissue. A proteomic approach seems valuable, and identified several candidates not previously associated with AAA. Larger studies are required to confirm the potential and clinical role of the identified proteins.