Nonruptured Abdominal Aortic Aneurysm Research Articles

Symptomatic Nonruptured Abdominal Aortic Aneurysm

Symptomatic Nonruptured Abdominal Aortic Aneurysm

Deficiency of peroxiredoxin 2 exacerbates angiotensin II-induced abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is an inflammatory vascular disease characterized by structural deterioration of the aorta caused by inflammation and oxidative stress, leading to aortic dilatation and rupture. Peroxiredoxin 2 (PRDX2), an antioxidant enzyme, has been reported as a potential negative regulator of inflammatory vascular diseases, and it has been identified as a protein that is increased in patients with ruptured AAA compared to patients with nonruptured AAA. In this study, we demonstrated that PRDX2 was a pivotal factor involved in the inhibition of AAA progression. PRDX2 levels were increased in AAA compared with those in normal aortas in both humans and mice. Ultrasound imaging revealed that the loss of PRDX2 accelerated the development of AAA in the early stages and increased AAA incidence in mice infused with angiotensin II (Ang II). Prdx2−/− mice infused with Ang II exhibited increased aortic dilatation and maximal aortic diameter without a change in blood pressure. Structural deterioration of the aortas from Prdx2−/− mice infused with Ang II was associated with increases in the degradation of elastin, oxidative stress, and intramural thrombi caused by microhemorrhages, immature neovessels, and the activation of matrix metalloproteinases compared to that observed in controls. Moreover, an increase in inflammatory responses, including the production of cell adhesion molecules and the accumulation of inflammatory cells and proinflammatory cytokines due to PRDX2 deficiency, accelerated Ang II-induced AAA progression. Our data confirm that PRDX2 plays a role as a negative regulator of the pathological process of AAA and suggest that increasing PRDX2 activity may be a novel strategy for the prevention and treatment of AAA.

Predictors of Abdominal Aortic Aneurysm Risks.

Computational biomechanics via finite element analysis (FEA) has long promised a means of assessing patient-specific abdominal aortic aneurysm (AAA) rupture risk with greater efficacy than current clinically used size-based criteria. The pursuit stems from the notion that AAA rupture occurs when wall stress exceeds wall strength. Quantification of peak (maximum) wall stress (PWS) has been at the cornerstone of this research, with numerous studies having demonstrated that PWS better differentiates ruptured AAAs from non-ruptured AAAs. In contrast to wall stress models, which have become progressively more sophisticated, there has been relatively little progress in estimating patient-specific wall strength. This is because wall strength cannot be inferred non-invasively, and measurements from excised patient tissues show a large spectrum of wall strength values. In this review, we highlight studies that investigated the relationship between biomechanics and AAA rupture risk. We conclude that combining wall stress and wall strength approximations should provide better estimations of AAA rupture risk. However, before personalized biomechanical AAA risk assessment can become a reality, better methods for estimating patient-specific wall properties or surrogate markers of aortic wall degradation are needed. Artificial intelligence methods can be key in stratifying patients, leading to personalized AAA risk assessment.

Intravenous ketorolac is associated with reduced mortality and morbidity after open abdominal aortic aneurysm repair.

The role of non-steroidal anti-inflammatory drugs in aortic aneurysm disease has been debated. Animal studies demonstrated that intrathecal ketorolac reduces the inflammatory response associated with aortic clamping. However, no human-subject study evaluated this association. Therefore, we sought to explore the effects of ketorolac use in open abdominal aortic aneurysm repair. The Premier Healthcare Database (June 2009-March 2015) was inquired to capture patients who underwent open abdominal aortic aneurysm repair for non-ruptured abdominal aortic aneurysm, identified via International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes. Intravenous ketorolac was coded as any or none. Outcomes were in-hospital mortality, cardiac, respiratory, renal, neurological, and hemorrhagic complications. Multivariable logistic regression coarsened exact matching followed by conditional fixed-effect regression modeling were performed. A total of 6394 patients were identified (ketorolac: 806; 12.6%). Patients who received ketorolac were younger and less likely to have hypertension (76.1% vs. 79.3%), diabetes mellitus (12.5% vs. 17.4%), or chronic kidney disease (8.3% vs. 21.4%; all p values ≤ .033). There was no significant difference in medication use including oral non-steroidal anti-inflammatory drugs and malignant or musculoskeletal diseases. Mortality, respiratory, and renal complications were less prevalent with ketorolac (2.5% vs. 4.9%, 25.2% vs. 34.6%, 10.0% vs. 21.1%; p ≤ .002). Ketorolac was associated with lower adjusted odds for those events: 0.58 (0.36-0.93), 0.53 (0.42-0.68), and 0.72 (0.60-0.86), respectively (all p values ≤ .025). There was no association with neurological, cardiac, or hemorrhagic complications. The findings were replicated by coarsened exact matching analysis. This study demonstrated 40% mortality reduction with intravenous ketorolac following open abdominal aortic aneurysm repair. The survival benefit could be due to its anti-inflammatory and opioid-sparing properties. This is evident by its protective effect against respiratory outcomes. The lack of association with the classical non-steroidal anti-inflammatory drugs-related cardiac and hemorrhagic complication could be attributable to the short-term use of ketorolac compared with non-steroidal anti-inflammatory drugs chronic use.

Low Iliofemoral Calcium Score May Predict Higher Survival after EVAR and FEVAR

Abdominal aortic aneurysm is associated with an increased mortality, mostly cardiovascular events. Moreover, aortoiliac calcification is associated with increased mortality in patients with peripheral occlusive disease. The aim of this study is to assess the potential association between iliofemoral calcification, assessed by calcium score, in patients undergoing infrarenal (endovascular aneurysm repair [EVAR]) or fenestrated endovascular aortic repair (FEVAR) and long-term mortality, particularly caused by cardiac events. All patients with preoperative noncontrast-enhanced computed tomographic scans who underwent infrarenal EVAR and FEVAR of nonruptured abdominal aortic aneurysm between 2004 and 2012 at a single tertiary center were screened for inclusion. Agatston calcium score was measured from the aortic bifurcation to common femoral arteries using a dedicated postprocessing software. The values are presented as median and interquartile range. About 404 (62.05%) of 651 patients who underwent EVAR and FEVAR had sufficient imaging quality to be included. There was no difference in survival between included and excluded patients (P=0.33). Nine patients (2.2%) died within 30days of the operation, whereas the remaining were followed up for 6.3 (4.7-8.4) years. The iliofemoral calcium score was 8348 (3830-14,179). Estimated overall survival at 5years was 73±2%. Patients within the lowest quartile of iliofemoral calcium score had significantly higher overall survival (5years: 79±4% vs. 71±3%; P=0.01) and cardiac event-free survival (5years: 95±2% vs. 91±2%; P=0.033) when compared with the remaining ones. Calcium score was associated with neither univariate regression analysis with survival (odds ratio, 1.016 [0.988-1.045]; P=0.268) nor cardiac event-free survival (odds ratio, 1.024 [0.986-1.063]; P=0.222). Low iliofemoral calcium score may be associated with lower incidence of fatalcardiac events and all-cause long-term mortality after EVAR and FEVAR. This may be partially a reflection of aging and cardiovascular comorbidity but needs to be studied further.

Endovascular aneurysm repair for symptomatic abdominal aortic aneurysms has comparable results to elective repair in the long term

ObjectiveEndovascular aneurysm repair (EVAR) has been extensively study regarding elective and ruptured abdominal aortic aneurysm (AAA) repair. However, much less is known about EVAR of symptomatic nonruptured AAA, especially concerning the long-term results. The aim of this study was to assess the outcomes of EVAR of symptomatic AAA compared with asymptomatic AAA at a tertiary center using a single graft. MethodsAll consecutive patients treated for symptomatic and asymptomatic AAAs from 1998 to 2012 at our institution, using the Cook Zenith stent graft (Cook Europe A/S, Bjaeverskov, Denmark), were included in the study. Ruptured AAAs were excluded. Patients' charts were reviewed to obtain preoperative, intraoperative, and postoperative data. All available imaging was reviewed. Life tables were constructed to assess for overall and late AAA-related survival, clinical success, and endoleak freedom. ResultsThere were 680 patients included (137 symptomatic AAAs). No difference in technical success rate (96.1% for asymptomatic AAAs vs 94.9% for symptomatic AAAs) was present (P = .477). Thirty-day mortality was more common in symptomatic AAAs (6.6% vs 1.5% for asymptomatic AAAs; P = .002). Freedom from reinterventions was 72% ± 3% for asymptomatic AAAs vs 73% ± 5% for symptomatic AAAs (P = .785) at 10 years postoperatively. There was no difference in primary (P = .300) or secondary (P = .099) clinical success between groups, although there was higher assisted clinical success (P = .023) for asymptomatic AAAs compared with symptomatic AAAs. Persistent late clinical failure was similar in both groups (14.2% for asymptomatic AAAs vs 15.3% for symptomatic AAAs; P = .732). Freedom from late AAA-related death was higher (P = .016) for asymptomatic AAAs compared with symptomatic AAAs, but the differences disappeared when the first 30 days were disregarded. Overall survival (P = .687) was similar in both groups. An adequate aneurysm neck preoperatively conferred a better outcome in end points including overall survival. ConclusionsSymptomatic AAAs have an almost quadrupled 30-day mortality compared with asymptomatic AAAs, but the outcome differences fade in the long term. An adequate aneurysm neck was associated with better outcomes including overall survival independent of the initial presentation of the AAA. These results suggest the need of improving the identification of symptomatic patients requiring preoperative medical optimization. However, this is often limited by the acute need of the procedure, and more intensive postoperative monitoring may have greater potential. Independently, a strict anatomic selection for infrarenal EVAR is of paramount importance for the long-term outcome.

CCR2 Positron Emission Tomography for the Assessment of Abdominal Aortic Aneurysm Inflammation and Rupture Prediction.

The monocyte chemoattractant protein-1/CCR2 (chemokine receptor 2) axis plays an important role in abdominal aortic aneurysm (AAA) pathogenesis, with effects on disease progression and anatomic stability. We assessed the expression of CCR2 in a rodent model and human tissues, using a targeted positron emission tomography radiotracer (64Cu-DOTA-ECL1i). AAAs were generated in Sprague-Dawley rats by exposing the infrarenal, intraluminal aorta to PPE (porcine pancreatic elastase) under pressure to induce aneurysmal degeneration. Heat-inactivated PPE was used to generate a sham operative control. Rat AAA rupture was stimulated by the administration of β-aminopropionitrile, a lysyl oxidase inhibitor. Biodistribution was performed in wild-type rats at 1 hour post tail vein injection of 64Cu-DOTA-ECL1i. Dynamic positron emission tomography/computed tomography imaging was performed in rats to determine the in vivo distribution of radiotracer. Biodistribution showed fast renal clearance. The localization of radiotracer uptake in AAA was verified with high-resolution computed tomography. At day 7 post-AAA induction, the radiotracer uptake (standardized uptake value [SUV]=0.91±0.25) was approximately twice that of sham-controls (SUV=0.47±0.10; P<0.01). At 14 days post-AAA induction, radiotracer uptake by either group did not significantly change (AAA SUV=0.86±0.17 and sham-control SUV=0.46±0.10), independent of variations in aortic diameter. Competitive CCR2 receptor blocking significantly decreased AAA uptake (SUV=0.42±0.09). Tracer uptake in AAAs that subsequently ruptured (SUV=1.31±0.14; P<0.005) demonstrated uptake nearly twice that of nonruptured AAAs (SUV=0.73±0.11). Histopathologic characterization of rat and human AAA tissues obtained from surgery revealed increased expression of CCR2 that was co-localized with CD68+ macrophages. Ex vivo autoradiography demonstrated specific binding of 64Cu-DOTA-ECL1i to CCR2 in both rat and human aortic tissues. CCR2 positron emission tomography is a promising new biomarker for the noninvasive assessment of AAA inflammation that may aid in associated rupture prediction.

Type 2 Diabetes and Abdominal Aortic Aneurysm: Association Between Insulin Resistance Index and AAA Diameter

Introduction: Abdominal aortic aneurysm (AAA) is most often associated with atherosclerosis and corresponding cardiovascular risk factors. However, epidemiological studies have paradoxically highlighted a negative association between diabetes and AAA. The pathways involved are still poorly understood. Type 2 diabetes is characterized by insulin resistance associated with defects in insulin secretion. The aim of this study was to investigate the link between insulin resistance and AAA size. Methods: Patients with non-ruptured AAA were prospectively included between January 2016 and February 2017. Patients with AAA caused by specific etiologies such as infectious or genetic diseases were excluded. Fasting blood samples were collected to measure glucose, fructosamine, insulin, C-peptide and calculate insulin resistance according to the homeostasis model assessment (HOMA2 IR). The population was divided into 2 groups according to the median value of AAA diameter (< 50 mm et ≥ 50 mm). Group differences were compared using non-parametric Mann-Whitney test for continuous variables. Fisher’s exact test was used for categorical data. Correlations were determined by non-parametric Spearman’s correlation coefficient. Results: Fifty-five patients were included, with 87.3% of men. The median age of the cohort was 72 years (66- 79). Demographic characteristics as well as the presence of cardiovascular risk factors were similar between patients with AAA≥ 50 mm and those with AAA< 50 mm. Patients with AAA≥ 50 mm had similar fasting glycemia compared to those with AAA< 50 mm (6.1 vs 5.9 mmol/L, p=0.825). C-peptide and insulin concentrations were significantly higher in patients with AAA≥ 50 mm (0.82 vs 0.54 nmol/L, p=0.012 and 9 vs 5 mU/L, p=0.019). This was associated with a higher insulin resistance index (HOMA2 IR index: 1.72 vs 1.26, p=0.028). Fructosamine concentration was lower in patients with AAA> 50 mm (225.5 vs 251 μmol/L, p=0.005) and negatively correlated with AAA diameter (r=-0.55, p<0.0001). Conclusion: Patients with AAA≥ 50 mm had significantly higher insulin resistance index. Further clinical and fundamental studies are required to determine a causal link between insulin resistance and AAA development. This could, at term, lead to the identification of new therapeutic targets.

Increased m6A methylation level is associated with the progression of human abdominal aortic aneurysm.

The role of N6-methyladenosine (m6A) modification in abdominal aortic aneurysm (AAA) has not been extensively studied. This study therefore aimed to investigate m6A RNA methylation and the expressions of the corresponding modulators in AAA. A comparative study between AAA tissue samples (n=32) and healthy aortas (n=12) was performed using m6A methylation quantification for messenger RNA (mRNA) m6A status, quantitative polymerase chain reaction (qPCR), and western blot for the expressions of m6A modulators and immunohistochemistry (IHC) to detect locations of the modulators in AAA tissues. The m6A level significantly increased in AAA as compared to healthy aorta tissues. Among AAA patients, the high m6A level represented an even greater risk of AAA rupture as compared to non-ruptured AAA [odds ratio (OR), 1.370; 95% confidence interval (CI), 1.007-1.870]. The major N6-adenosine modulators, including YTHDF1, YTHDF3, FTO, and METTL14, are the main factors involved in aberrant m6A modification and the expression of both was significantly correlated to the proportion of m6A in total mRNA. Clinically, YTHDF3 represented an even greater risk of rupture (OR, 1.036; 95% CI, 1.001-1.072). Regarding the cellular location, METTL14 seemed to be associated with inflammatory infiltrates and neovascularization. Furthermore, a strong correlation was seen between FTO and aneurysmal smooth muscle cells (SMCs), YTHDF3, and macrophage infiltrate. We were first to observe m6A modification in human AAA tissues. The results also reveal the important roles of m6A modulators, including YTHDF3, FTO, and METTL14, in the pathogenesis of human AAA and provide a new view on m6A modification in AAA. Our findings suggest a potential mechanism of epigenetic alterations in clinical AAA.

The role of the inferior mesenteric artery in predicting secondary intervention for type II endoleak following endovascular aneurysm repair

ObjectiveEndovascular aneurysm repair (EVAR) is associated with a greater risk of graft-related complications and need for secondary interventions compared with open repair. Type II endoleak (EL-2) is the most common complication. We examined the hypothesis that a functionally occluded inferior mesenteric artery (IMA) before EVAR was associated with fewer secondary interventions for EL-2. MethodsAll nonruptured abdominal aortic aneurysms (AAA) treated by EVAR using U.S. Food and Drug Administration-approved endografts from January 2005 to December 2017 were retrospectively reviewed, including computed tomography angiograms. Preoperative patency of the IMA and any secondary interventions performed after the index EVAR procedure were recorded. A functionally occluded IMA was defined as one that was (1) chronically occluded or severely stenosed on preoperative imaging or (2) coil embolized before EVAR. Secondary interventions for persistent EL-2 were indicated when AAA sac diameter increased by more than 5 mm. ResultsThe study cohort comprised 490 patients (84 women) with a mean age of 74.8 ± 8.2 years. The mean preoperative AAA diameter was 5.6 ± 0.9 cm. One hundred twenty-nine patients (26.3%) died during follow-up. The mean follow-up of survivors was 38 months. Types (prevalence) of endoleak were I (2.4%), II (18.9%), III (0.7%), IV (0.5%), and V (0.2%). Patients with a functionally occluded IMA underwent significantly fewer secondary interventions for EL-2 compared with patients with a patent IMA (2.6% vs 7.1%; P = .020). All secondary interventions in the functionally occluded IMA group involved the lumbar arteries (LA). When the IMA was patent, secondary interventions were equally distributed between the LA and IMA. Logistic regression confirmed that a functionally patent IMA was associated with a greater number of secondary interventions for EL-2 (odds ratio, 3.0; 95% confidence interval, 1.2-7.5; P = .025). ConclusionsPatients with a functionally occluded IMA required significantly fewer secondary interventions for EL-2 after EVAR. In addition, the type of vessels intervened on were primarily LA. Among patients with a patent IMA, preoperative coil embolization may decrease secondary interventions and improve the long-term durability of EVAR.

Vascular Surgery in Japan: 2012 Annual Report by the Japanese Society for Vascular Surgery.

Objectives: This is an annual report indicating the number and early clinical results of annual vascular treatments performed by vascular surgeons in Japan in 2012, as analyzed by database management committee (DBC) members of the JSVS.Materials and Methods: To survey the current status of vascular treatments performed by vascular surgeons in Japan, the DBC members of the JSVS analyzed the vascular treatment data provided by the NCD vascular surgery data analysis team, including the number of treatments and early clinical results such as operative and in-hospital mortality.Results: In total 95,979 vascular treatments were registered by 1,043 institutions in 2012. This database is composed of 7 fields including treatment of aneurysms, chronic arterial occlusive disease, acute arterial occlusive disease, vascular injury, complication of previous vascular reconstruction, venous diseases, and other vascular treatments. The number of vascular treatments in each field was 19,600, 13,141, 4,600, 1,623, 1,973, 30,725, and 24,332, respectively. In the field of aneurysm treatment, 15,745 cases with abdominal aortic aneurysms (AAA) including common iliac aneurysms were registered, and 47.6% were treated by stent graft. Among AAA cases, 1,704 (10.8%) cases were registered as ruptured AAA. The operative mortality of ruptured and non-ruptured AAA was 17.8%, and 0.8%, respectively. Regarding chronic arterial occlusive disease, open repair was performed in 7,859 cases, including 1,173 distal bypasses to the crural or pedal artery, whereas endovascular procedures were performed in 5,282 cases. Venous treatment including 30,088 cases with varicose vein treatments and 395 cases with lower limb deep venous thrombosis were registered. Regarding other vascular operations, 22,654 cases of vascular access operations and 1,390 amputation surgeries were included. The number of lower limb amputations was still increasing and the mortality rate of amputation surgery was also still high; both of these issues require improvement.Conclusions: The number of vascular treatments increased since 2011, and the proportion of endovascular procedures increased in almost all fields of vascular diseases, especially endovascular aneurysm repair (EVAR) for aneurysms and endovenous laser ablation (EVLA) for varicose veins. (This is a translation of Jpn J Vasc Surg 2018; 27: 437–456.)

Assessing trends, morbidity, and mortality in ruptured abdominal aortic aneurysm repair with 9 years of data from the National Surgical Quality Improvement Program

BackgroundThe American College of Surgeons' National Quality Improvement Program (NSQIP) database can be used to assess trends and outcomes of ruptured abdominal aortic aneurysm (rAAA) repair. The purpose of this study is to examine the morbidity and mortality for ruptured endovascular (rEVAR) and ruptured open (rOPEN) aneurysm repair compared with elective endovascular (EVAR) and elective open (OPEN) aneurysm repair. MethodsRuptured and nonruptured abdominal aortic aneurysms were identified from the NSQIP database between 2008 and 2016. Data regarding demographics and comorbidities, 30-day mortality, and postoperative complications were collected for rEVAR, rOPEN, EVAR, and OPEN cases. ResultsThere were 43,105 AAAs, 34,177 (79.28%) EVARs, and 8928 (20.71%) OPENs. There were 3806 rAAAs, 1843 (48.42%) rEVARs, and 1963 (51.58%) rOPENs. The incidence of rEVAR repair lagged behind EVAR considerably. Mortality for rOPEN was 575 (29.29%) and 344 (18.66%) for rEVAR. No difference between the ratio of men to women in rOPEN vs rEVAR was noted. There was a significant increase in mortality for women vs men undergoing rEVAR (P = .0362). No difference in mortality existed between women vs men undergoing rOPEN (P = .0639). There was no difference in the percentage of hypotensive cases undergoing rEVAR vs rOPEN (P =.1873). For all rAAAs with hypotension, rOPEN had an increased mortality compared to rEVAR (P = .0004). There were 20 (3.11%) rEVAR and 40 (8.00%) rOPEN cases with lower extremity ischemia. rOPEN conferred a significant increase in lower extremity ischemia (P = .0002). There were 46 (7.15%) rEVAR and 60 (12.00%) rOPEN cases of ischemic colitis. rOPEN had a significant increase in ischemic colitis (P = .0052). ConclusionsNSQIP data, over 9 years, demonstrate an increased morbidity and mortality associated with open vs endovascular repair of rAAAs. A great disparity exists between the proportion of rEVAR and rOPEN to EVAR and OPEN. The lagging use of endovascular repair of rAAAs must be further explored.

Real-world cost analysis of endovascular repair versus open repair in patients with nonruptured abdominal aortic aneurysms

BackgroundThe aim of this study was to provide a nationwide, all-payer, real-world cost analysis of endovascular aortic aneurysm repair (EVAR) versus open aortic aneurysm repair (OAR) in patients with nonruptured abdominal aortic aneurysms (non-rAAA). MethodsAll non-rAAA patients registered between July 2009 and March 2015 in the Premier Healthcare Database were analyzed. The Student t-test and the χ2 test were used for continuous and categorical variables, respectively; median value comparisons were done with the Wilcoxon-Mann-Whitney rank-sum test. The in-hospital absolute mean total cost (sum of fixed cost and variable cost) and subcategories were analyzed after adjustment for inflation at July 2015. Fixed costs included all overhead costs while variables costs included in-hospital services including procedures, room and board, services provided by hospital staff, and pharmacy costs. Total cost was stratified based on admission type (emergency vs nonemergency), 75th percentile of length of hospital stay among individual procedures (expected vs extended stay), mortality, and complications. Student t-test and Fisher's analysis of variance were used for comparing mean cost. Year-wise comparison of mean cost was done with analysis of variance to look for a trend over time. ResultsOur study cohort included 38,809 non-rAAA patients (33,171 EVAR and 5638 OAR). The mean total cost of index admission was lower in EVAR in comparison with OAR ($32,052 vs $36,091; P < .001), with lower fixed costs ($11,309 vs $16,818; P < .001) and higher variable costs ($20,743 vs $19,272; P < .001). Cost of pharmacy, labor, operating room, room and board and other costs were significantly higher with OAR, whereas the supply cost was higher with EVAR. The expected hospital length of stay of patients who underwent EVAR was associated with a higher total cost ($27,271 vs $25,680; P < .001) and a higher variable cost ($18,186 vs $13,671; P < .001) than OAR patients. However, the extended hospital stay of patients who underwent EVAR had lower costs in all categories compared with the extended length of stay of those who underwent OAR. Mortality associated with EVAR was costlier than OAR associated mortality (mean $72,483 vs $59,804; P = .017). From 2009 to 2014, the mean total cost of EVAR increased significantly by 18.5% ($28,745 vs $34,049; P < .001) owing to a 7.8% increase in fixed costs ($10,931 vs $11,789; P < .001) and a 25.0% increase in variable costs ($17,804 vs $22,257; P < .001). The mean total cost OAR remained stable over time. ConclusionsOverall hospitalization costs associated with EVAR of non-rAAA was lower than the hospitalization cost of OAR. Interestingly, we found that, among patients who had an expected hospital length of stay, the hospitalization cost after OAR was significantly lower than after EVAR. The average hospitalization cost of OAR was stable during the 5 years study period, whereas the hospitalization cost of EVAR increased significantly over time. Further studies are required to identify reasons for increased costs associated with EVAR.

GRADE-Based Recommendations for Surgical Repair of Nonruptured Abdominal Aortic Aneurysm.

The objective of this study was to provide evidence-based recommendations for endovascular aneurysm repair (EVAR) versus open surgical repair (OSR) for patients with a nonruptured abdominal aortic aneurysm (AAA). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement and adhered to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Both low- and high surgical risk patients treated with EVAR showed decreased 30-day mortality, but the low-risk group had no differences in 4-year mortality. Compared with friendly anatomy, patients with hostile anatomy had an increased risk of type I endoleak. Young patients may prefer OSR. Endovascular aneurysm repair was not cost-effective in Europe. Four conditional recommendations were formulated: (1) OSR for low-risk patients up to 80 years old, (2) EVAR for low-risk patients older than 80 years, (3) EVAR for high-risk patients as long as is anatomically feasible, and (4) OSR in patients in whom it is not anatomically feasible to perform EVAR. Based on GRADE criteria, either OSR or EVAR can be suggested to patients with nonruptured AAA taking into account their surgical risk, hostile anatomy, and age. Given the weakness of the recommendations, personal preferences are determinant.

Uncertain progress in Swiss perioperative mortality 1998-2014 for 22 operation groups.

The perioperative mortality rate (POMR) is used as a quality indicator to monitor health care system performance at regional and national levels. The Swiss Federal Office of Public Health publishes national in-hospital mortality rates for several indicator conditions and indicator operation types (IORs). We investigated long-term time trends of POMRs from 1998-2014. In view of continual advances in perioperative care, we expected to find decreasing trends. Non-cardiosurgical IORs containing aggregated age- and sex-specific data (number of operations and deaths) for all years of the study period were included to calculate age-standardised POMRs using the 2013 European Standard Population. We assessed calendar time trends of POMRs using multivariable Poisson regression. We categorised IORs according to the type of time trend (decreasing, unchanged, or increasing incident rate ratio) and mean risk levels (age-adjusted POMR). A total of 22 IORs were included, comprising 1,561,012 operations and 22,140 deaths (overall crude POMR 1.42%). POMR trends decreased for 6 IORs representing 26.8% of operations, remained unchanged for 13 IORs (56.9% of operations), and increased for 3 IORs (16.4% of operations). IOR categorisation according to POMR trends and to risk levels yielded four groups. (1) Decreasing POMR trends, low- to intermediate-risk IORs (age-adjusted POMR 0.2-2.2%): cholecystectomy; arterial pelvic/leg aneurysm or dissection operation; femoral neck fracture; trochanteric fractures; gastric, duodenal or jejunal ulcer resection; major pulmonary or bronchial resection. (2) Unchanged POMR trends, low-risk IORs (0.1-0.9%): transurethral resection of the prostate (TUR prostate); hernia repair without intestinal operation; hysterectomy; extracranial vascular operation; nephrectomy; amputation foot, non-traumatic. (3) Unchanged POMR trends, intermediate-risk IORs (1.7-3.8%): hernia repair with intestinal operation; gastric carcinoma resection; non-ruptured abdominal aortic aneurysm (open operation); arterial pelvic/leg thromboembolic operation; colorectal resection, pancreatic resection; complex oesophageal procedure. (4) Increasing POMR trends, low- to high-risk IORs (0.1-5.2%): hip endoprosthesis; cystectomy; amputation lower limb. Impact of sex on POMR: hysterectomy and TUR prostate comprised 19.7% of all operations; among the remaining operations, 68.5% showed significantly lower and 27.1% significantly higher POMRs in females. 4.4% showed no sex difference. In Switzerland, in-hospital POMR trends from 1998-2014 were unchanged or even increasing for the majority of IORs (73% of included operations). Our analysis used age-standardisation but cannot account for changes in coding practices and organisation of healthcare delivery. POMR trends should be systematically monitored at the national level and used to guide priorities in national quality improvement strategies.

Reduced length of stay and 30-day readmission rate on an inpatient vascular surgery service

As the cost of care for patients with specific diagnoses becomes fixed, hospitals must develop systems to reduce length of stay and optimize the use of hospital resources while maintaining a high quality of care. The goal of this study is to evaluate the implementation and efficacy of a system designed to reduce average length of stay on a vascular surgery service. To effectively reduce the average length of stay in our center, we restructured patient rounds, implemented multidisciplinary rounds, introduced clinical pathways to postoperative care, and expanded outpatient management of postoperative patients. A total of 1697 adult vascular surgery patients discharged while under the medical direction of a vascular surgeon between July 1, 2013, and June 30, 2016, were included in the study. Improving communication with critical staff and using procedural space outside of the main operating rooms led to a 2.8-day reduction in the length of stay (10.8 vs 8.0, P<.001). There was a trend toward a reduction in the 30-day readmission rate (12% vs 10%, respectively; P=.01) and no significant difference in the case-mix index as a measure of illness severity (2.5 vs 2.4, respectively; P=.15). Length of stay reductions were heterogeneous among the types of vascular diseases studied, with greater improvements seen in patients undergoing lower extremity amputation, lower extremity angiogram, and endovascular aneurysm repair for nonruptured abdominal aortic aneurysms. Less pronounced differences were observed in patients undergoing carotid artery endarterectomy or stenting and lower extremity bypasses. In conclusion, restructuring team rounds and instituting a multidisciplinary approach to discharge planning produced significant reductions in length of stay without a deleterious effect on patient care which may impact hospital profitability.

The Nellix endovascular aneurysm sealing system: current perspectives.

BackgroundThe Nellix endovascular aneurysm sealing (EVAS) system is a novel approach for the treatment of abdominal aortic aneurysm (AAA). We aimed to evaluate the efficacy of EVAS in the management of patients with AAA.Materials and methodsWe searched PubMed/MEDLINE, CINAHL, and bibliographic reference lists to identify studies reporting clinical outcomes in patients with asymptomatic, non-ruptured AAA treated with EVAS with the Nellix device. We pooled dichotomous outcome data using random-effects models.ResultsWe identified 14 single-arm observational studies, reporting a total of 1,510 patients. The pooled estimate of technical success was 99% (95% CI =98–100; heterogeneity: P=0.869, I2=0%). Adjunctive procedures were carried out in 39% (95% CI =19–63; heterogeneity: P<0.0001, I2=88%). Two cases of aneurysm rupture were reported within 30 days of treatment (0.7%, 95% CI =0.3–1.6; heterogeneity: P=0.923, I2=0%) and another five cases of rupture occurred during follow-up (0.8%, 95% CI =0.4–1.6; heterogeneity: P=0.958, I2=0%). The pooled estimates of early (within 30 days) and late (during follow-up) type I endoleak were 2.8 % (95% CI =1.8–4.2; heterogeneity: P=0.254, I2=18%) and 1.9% (95% CI =1.3–2.8; heterogeneity: P=0.887, I2=0%), respectively. Sac enlargement was noted in 3.1% (95% CI =1.8–5.4; heterogeneity: P=0.419, I2=0%) and device migration in 2.1% (95% CI =0.8–5.3; heterogeneity: P=0.004, I2=65%). The early and late reintervention rates were 2.7% (95% CI =1.7–4.2; heterogeneity: P=0.183, I2=27%) and 3.5% (95% CI =2.3–5.5; heterogeneity: P=0.061, I2=42%), respectively. The pooled estimate of 30-day mortality was 1.5% (95% CI =0.9–2.6; heterogeneity: P=0.559, I2=0%) and the pooled estimate of aneurysm-related death during follow-up was 1.0% (95% CI =0.6–1.9; heterogeneity: P=0.872, I2=0%).ConclusionReported outcomes of EVAS are acceptable. Type I endoleak, sac enlargement, device migration, and aneurysm rupture are recognized complications. High-level research is required to investigate potential advantages of EVAS over conventional treatments.

Reduced stage 2 sleep in patients with adrenal insufficiency

As the cost of care for patients with specific diagnoses becomes fixed, hospitals must develop systems to reduce length of stay and optimize the use of hospital resources while maintaining a high quality of care. The goal of this study is to evaluate the implementation and efficacy of a system designed to reduce average length of stay on a vascular surgery service. To effectively reduce the average length of stay in our center, we restructured patient rounds, implemented multidisciplinary rounds, introduced clinical pathways to postoperative care, and expanded outpatient management of postoperative patients. A total of 1697 adult vascular surgery patients discharged while under the medical direction of a vascular surgeon between July 1, 2013, and June 30, 2016, were included in the study. Improving communication with critical staff and using procedural space outside of the main operating rooms led to a 2.8-day reduction in the length of stay (10.8 vs 8.0, P < .001). There was a trend toward a reduction in the 30-day readmission rate (12% vs 10%, respectively; P = .01) and no significant difference in the case-mix index as a measure of illness severity (2.5 vs 2.4, respectively; P = .15). Length of stay reductions were heterogeneous among the types of vascular diseases studied, with greater improvements seen in patients undergoing lower extremity amputation, lower extremity angiogram, and endovascular aneurysm repair for nonruptured abdominal aortic aneurysms. Less pronounced differences were observed in patients undergoing carotid artery endarterectomy or stenting and lower extremity bypasses. In conclusion, restructuring team rounds and instituting a multidisciplinary approach to discharge planning produced significant reductions in length of stay without a deleterious effect on patient care which may impact hospital profitability.

The Potential Role of Neutrophil Gelatinase-Associated Lipocalin in the Development of Abdominal Aortic Aneurysms

In abdominal aortic aneurysm (AAA), pathophysiology deterioration of the medial aortic layer plays a critical role. Key players in vessel wall degeneration are reactive oxygen species (ROS), smooth muscle cell apoptosis, and extracellular matrix degeneration by matrix metalloproteinase-9 (MMP-9). Lipocalin-2, also neutrophil gelatinase-associated lipocalin (NGAL), is suggested to be involved in these degenerative processes in other cardiovascular diseases. We aimed to further investigate the role of NGAL in AAA development and rupture. In this observational study, aneurysm tissue and blood of ruptured (n=13) AAA patients were investigated versus nonruptured (n=26) patients. Nondilated aortas (n=5) from deceased patients and venous blood from healthy volunteers (n=10) served as controls. NGAL concentrations in tissue and blood were measured by enzyme-linked immunosorbent assay and immunofluorescence microscopy. Nitrotyrosine (marker of ROS), MMP-9, and caspase-3 (marker of apoptosis) in aneurysm tissue were measured by immunofluorescence microscopy. AAA expansion rates were calculated retrospectively. NGAL (in μg/mL) blood concentration in ruptured AAA was 46 (range 22-122) vs. 26 (range 6-55) in nonruptured AAA (P<0.01) and 14 (range 12-22) in controls (P<0.01). In the aneurysm wall of ruptured AAA, NGAL concentration was 4.7 (range 1.4-25) vs. 4.4 (range 0.2-14) in nonruptured AAA (not significant) and 1.8 (range 1.2-2.7) in nondilated aortas (P=0.04). In the medial layer, NGAL correlated positively with nitrotyrosine (Rs=0.80, P<0.01), MMP-9 (Rs=0.56, P=0.02), and caspase-3 (Rs=0.75, P=0.01). NGAL did not correlate to AAA expansion rate in blood or tissue (P=0.34 and P=0.95, respectively). This study demonstrates that NGAL blood concentration is higher in ruptured AAA patients than in nonruptured AAA. NGAL expression in the AAA wall is also higher than in nondilated aorta. Furthermore, its expression is associated with factors of vessel wall deterioration. Based on our study results, we could not determine NGAL as a biomarker for AAA growth or rupture. However, our findings do support a potential role of NGAL in the development of AAA.

Significance of delayed surgical treatment of symptomatic non-ruptured abdominal aortic aneurysm

Introduction. An abdominal aortic aneurysm is a permanent focal dilation of the blood vessel wall to about 1.5 times larger than the normal diameter. Clinically, it may be divided into symptomatic and asymptomatic. It is still discussed whether patients with symptomatic non-ruptured abdominal aortic aneurysm benefit more from emergency or delayed surgical treatment. The aim of the study was to evaluate the results of the symptomatic non-ruptured aneurysms in regard to the diameter of ruptured and non-ruptured symptomatic aneurysms and the impact of the time elapsed from admission to surgery on its outcome. Material and Methods. The retrospective study included all 133 patients who underwent surgery due to symptomatic non-ruptured or ruptured abdominal aortic aneurysm at the Clinic of Vascular and Endovascular Surgery during the previous 3 years. Results. Out of a total of 133 patients, 75.19% underwent surgery in the first 24 hours after admission, while the rest 24.81% of patients were operated later. Intraoperative complications were recorded only in patients with ruptured aneurysms, 4% had cardiac arrest and 1.5% of patients had fatal outcome. The in-hospital mortality was 16.67% in patients with non-ruptured aneurysm of the abdominal aorta operated in the first 24 hours, and 9.91% in patients who were operated after 24 hours after admission. Conclusion. Early elective surgery is a method of choice in the treatment of symptomatic non-ruptured aneurysm of the abdominal aorta. However, surgical treatment in the first 24 hours is associated with a higher mortality rate than surgery after 24 hours after admission. Also, there is no statistically significant difference in the diameter of ruptured and non-ruptured symptomatic aneurysms, but the average size of the aneurysm diameter is higher in ruptured than in non-ruptured aneurysms, which confirms the fact that the increase in diameter increases the risk of aneurysm rupture.