Unruptured Abdominal Aortic Aneurysm Research Articles

Creation of a Shared Medical Decision Support Tool for the Management of Abdominal Aortic Aneurysms

ObjectivePatients with an unruptured abdominal aortic aneurysm (AAA) at the surgical threshold may benefit from aneurysmal exclusion either by open surgery or endovascular repair. A patient decision aid (PtDA) could be useful to help patients and their surgeons choose between the two techniques. The aim of this study was to develop a shared medical decision support tool, in french language, for the surgical treatment of AAA. MethodsFollowing the steps recommended by the International Patient Decision Aids Standards, we carried out a qualitative study using semi-structured interviews with patients and vascular surgeons and focus group with patients to identify their main points of interest. After analyzing the interviews using grounded theory with independent double coding, the verbatims were discussed at a steering committee, at the end of which a prototype of the tool was created. Results4 surgeons and 14 patients were interviewed. No new codes emerged from the last two interviews. At the end of the steering committee meeting, the informations selected for inclusion in the PtDA tool were the definition of an AAA, a description of the two surgical techniques (approach, duration of operation), the main complications, the peri-operative mortality rate, and post operative follow-up (length of hospital stay, monitoring frequency, risk of re-intervention). It had to be produced on a synthetic paper format, with six illustrations and a simple vocabulary. ConclusionWe developed a PtDA tool for use in a sharing decision making process with the patient during the consultation with the vascular surgeon and the general practitioner. Further studies are needed to validate the tool and to test it in clinical practice.

Morphology of Abdominal Aortic Aneurysms and Correlation with Biomechanical Tests of Aneurysmal Wall Fragments

Evaluate how specific morphologic aspects of abdominal aortic aneurysms (AAAs), including asymmetries, curvatures, tortuosities, and angulations, among others can influence the intrinsic biomechanical properties of the AAA's wall. This study analyzed the correlation of geometric measurements (1-dimensional, 2-dimensional, and 3-dimensional) of preoperative tomographic images of AAA with uniaxial biomechanical tests of the arterial wall fragments of these AAA obtained in open surgical repair of aneurysms. It was a multicenter, experimental, and observational study, and initially 54 individuals were selected who underwent open surgical of AAA, with valid biomechanical tests of the anterior wall of the AAA. Seven individuals were excluded because they had poor preoperative quality computed tomography scans and/or artifacts that impeded image segmentation and extraction of AAA geometric indices. The aortic fragments were subjected to uniaxial biomechanical destructive tests to obtain the following data: maximum load, failure stress, failure tension, failure strain energy, strain, and fragment thickness. In the same patients, preoperative computed tomography scans were performed with the extraction of 26 geometric indices, subdivided into 9 1-dimensional indices, 6 2-dimensional indices, and 11 3-dimensional indices. Data were subjected to statistical analysis using SPSS version28. Comparing ruptured and unruptured AAA, no statistical difference was observed between the biomechanical and geometric parameters. The fragment thickness of the ruptured AAA was lower than that of the unruptured AAA (P<0.05). By comparing tomographic geometric indices and biomechanical parameters of the aortic fragments using Pearson's coefficient, positive and linear correlations (P<0.05) were observed between the geometric variable maximum diameter (Dmax) of the AAA with maximum load (r=0.408), failure tension (r=0.372), and failure stress (r=0.360). Positive and linear correlations were also observed between the variable diameter/height ratio (DHr) and the maximum load (r=0.360), failure tension (r=0.354), and failure stress (r=0.289). The geometric variable DHr was dependent and correlated with Dmax. Simple regression analysis showed that R2 varied between 8.3% and 16.7%, and all models were significant (P<0.05). Dmax and DHr were linearly and positively correlated with the resistance parameters (maximum load, failure tension, and failure stress) of the AAA fragments. The DHr variable is dependent and correlated with Dmax. There was no correlation between the other geometric indices and the biomechanical parameters of the AAA wall. The asymmetries did not globally influence the biomechanics of AAA wall; however, they may influence regionally. Larger AAAs were stronger than smaller ones. Therefore, such findings may point toward Dmax is still the main geometric parameter, which influences the anterior wall, and possibly globally in the AAA.

The Treatment of Patients With an Unruptured Abdominal Aortic Aneurysm and a Concomitant Malignancy—Short- and Long-Term Results.

Having cancer adversely effects the outcome of treatment for an unruptured abdominal aortic aneurysm (AAA). A retrospective secondary analysis was performed on the basis of anonymized data from AOK, a German nationwide statutory health-insurance carrier. Data were evaluated from all of the 20 683 patients who underwent either endovascular (EVAR, 15 792) or open surgical (OAR, 4891) treatment for an unruptured AAA in the years 2010-2016. It was determined in each case whether the patient had a known cancer at the time of the procedure to treat AAA. The analysis concerned patient characteristics, periprocedural complications, and survival after the procedure up to 31 December 2018. 18 222 patients were free of cancer. In accordance with the known 6:1 sex ratio of AAA, 85.3% of the cancer-free patients and 92.8% of those with cancer were men. At the time of their AAA procedure, 1398 had cancer of the intestine (n = 318), lung (n = 301), prostate (n = 380), or bladder or ureter (n = 399). One-year survival after the AAA procedure was 91.5% in cancer-free patients and 84%, 74.4%, 85.8%, and 85.5% in the patients with the respective types of cancer just mentioned. Having cancer was a significant risk factor for periprocedural mortality (OR 1.326, p = 0.041) and for long-term survival (HR 1.515; p < 0.001). Having cancer is a risk factor for periprocedural mortality and long-term survival in patients undergoing treatment for an unruptured AAA. This implies that the indications for surgery should be considered with care, particularly in patients with lung cancer, whose 5-year survival rate is only 37.2%.

An Epidemiologic Study of the Incidence and Mortality of Abdominal Aortic Aneurysms in Koreans Aged ≥50 Years from 2009 to 2018 Based on a National Database.

Large-scale population studies of the incidence of and mortality from abdominal aortic aneurysm (AAA) are needed to develop healthcare policies and priorities. The aim of this study was to estimate the incidence of AAA and the all-cause mortality from it among Koreans aged ≥50 years from 2009 to 2018 using data from the Korean National Health Insurance System Database. The crude and standardized incidence and all-cause mortality of the disease among patients with unruptured AAA were calculated. A total of 73,933 AAA patients were identified. The overall incidence of AAA in adults ≥50 years during the study period was 37.5 per 100,000 population (49.7 per 100,000 in men and 26.8 per 100,000 in women), with an increase from 32.33 per 100,000 persons in 2009 to 46.85 per 100,000 in 2018. The crude all-cause mortality rate of patients with untreated AAA was 21.26/100 person-years in 2009 and 8.87/100 person-years in 2018, with decreasing trends observed both in men and women. This nationwide study showed that the incidence of AAA in Koreans aged ≥50 years in 2018 was 63.40 per 100,000 in men and 32.07 per 100,000 in women. The overall rates were 0.06% and 0.03%, respectively, with an increasing trend. Mortality has decreased in both treated and untreated patients. The observed increase in incidence suggests a rising burden of AAA in the Korean population, particularly among men. The decreasing mortality rates may indicate improvements in the management and treatment of AAA over the study period.

Management of symptomatic unruptured abdominal aortic aneurysms: state of the art

Management of symptomatic unruptured abdominal aortic aneurysms: state of the art

Influence of abdominal aortic aneurysm shape on hemodynamics in human aortofemoral arteries: A transient open-loop study

New imaging methods have enabled the detection of unruptured abdominal aortic aneurysms (AAA). It is necessary to develop appropriate mathematical models for rupture prediction to allow a proper patient treatment plan. To provide valid hemodynamic parameters, high-fidelity numerical models with patient-specific boundary conditions are needed. Researchers have pointed out in recent research articles and reviews that those morphological parameters, such as shape, dilation ratio, neck angle, common iliac bifurcation angle, and AAA type, consistently correlate with the rupture mechanism. However, it is unclear how morphological indicators affect hemodynamics-based computational fluid dynamics predictions. The present work investigates the influence of AAA shape on local and global hemodynamics parameters and rupture predictions. Five cases of magnetic resonance imaging scan-based data for patient-specific aortofemoral artery modeling are explored. The inflow conditions are patient-specific, and an open loop system has been considered to model all five cases. Hemodynamics parameters in pulsating conditions, such as wall shear stress (WSS), velocity contour, time average WSS (TAWSS), oscillatory shear index (OSI), vorticity, and streamlines, are computed and investigated. Both maximum dilation diameter and aneurysm neck angle are found to have substantial effects on local hemodynamics parameters. The magnitude of WSS, TAWSS, and OSI increases and decreases non-linearly with a change in maximum diameter during the cardiac process. Also, aneurysms with doubly titled and completely saccular shape show complex streamlines, low WSS, and high residence time in the sac area of the wall.

Intravascular Ultrasound Versus Computed Tomography Angiography in Sizing and Operative Management of Endovascular Aortic Aneurysm Repair.

An abdominal aortic aneurysm (AAA) is a potentially life-threatening condition, the management of which has dramatically evolved over the past 2 decades with an increasing tendency toward endovascular repair (EVAR) rather than open surgical repair. Classically, contrast-enhanced multislice computed tomography (CT) angiography (CTA) is performed preoperatively for procedure sizing and EVAR planning. This entails voluminous contrast injection with risk of allergic reaction, nephropathy, and radiation exposure. Intra-vascular ultrasound (IVUS) has been increasingly used to guide EVAR procedures intraoperatively. The aim of this study is to investigate the accuracy of IVUS in sizing AAAs, device selection, and EVAR planning compared to the gold standard CTA. This is a prospective observational study enrolling 10 patients who underwent standard infrarenal EVAR procedures performed for unruptured infrarenal AAAs over the course of 1 year. All patients had a preoperative CTA done upon which aneurysm sizing and device planning were performed, and the measurements obtained were compared to those obtained from intraoperative IVUS. All participating patients had unruptured infrarenal AAA, had no renal impairment, and had anatomical suitability for EVAR according to the instructions for use (IFU) of the device manufacturer. Primary endpoint was comparing anatomical measurements recorded by IVUS with those obtained from the preoperative CTA. Mean age was 65.6 (±6.19), all patients were males and hypertensives and 4 (40%) had a positive family history for AAA. On comparing mean measurements taken by CTA and IVUS, there was no statistically significant differences with exception of maximal aortic diameter and aortic diameter at site of bifurcation (both p-values <.001). There were no statistically significant differences in length measurements between the 2 imaging modalities. Computed tomography angiography was more associated with neck thrombus detection, and IVUS was more associated with calcification detection. Although CT angiography is still the gold standard imaging modality for AAA, IVUS use is very beneficial in EVAR sizing and planning, in addition to intra-operative guidance of the procedure, saving the patient significant time, contrast administration, and radiation exposure, especially in patients with renal impairment and contrast allergy. A preoperative CT angiogram is the gold standard required investigation for planning and sizing EVARs, with subsequent contrast injection entailing a risk of contrast induced nephropathy and allergic reactions. IVUS has been used as an adjuvant technique to guide EVAR stent graft deployment. However, our study concluded that it can also be reliably used in sizing and planning of the EVAR stent graft along with complementary non contrast imaging, especially in patients with high risk for contrast induced nephropathy and contrast allergy.

Identification and characterization of new candidates for abdominal aortic aneurysm screening in patients outside of current accepted guidelines

BackgroundPrevious studies have identified groups of patients with abdominal aortic aneurysm (AAA) that fall outside of currently accepted screening guidelines. Population-based studies have found AAA screening would be cost-effective at a prevalence of 0.5% to 1.0%. The goal of this study was to determine the prevalence of AAA in patients that fall outside of the current screening guidelines. In addition, we analyzed outcomes of the groups with a prevalence of greater than 1%. MethodsUsing the TriNetX Analytics Network, several patient cohorts were abstracted with a diagnosis of ruptured or unruptured AAA based on previously identified groups with a potentially high risk for AAA that fall outside of currently accepted screening guidelines. Groups were also stratified by sex. For groups found to have a prevalence of greater than 1%, the unruptured patients were further analyzed for long-term rates of rupture and included male ever-smokers aged 45 to 65, male never-smokers aged 65 to 75, male never-smokers aged greater than 75, and female ever-smokers aged 65 or greater. Long-term mortality, stroke, and myocardial infarction rates were compared in patients with treated and untreated AAA after propensity score matching. ResultsWe identified 148,279 patients across the four groups with a prevalence of AAA of greater than 1% with female ever-smokers aged 65 or older being the most prevalent (2.73%). In each of the four groups, the rate of AAA rupture increased every 5 years and all had rupture rates of greater than 1% at 10 years. Meanwhile, controls for each of these four subgroups without a previous AAA diagnosis had rupture rates between 0.090% and 0.013% at 10 years. Those who underwent repair of their AAA had decreased incidence of mortality, stroke, and myocardial infarction. Specifically, male ever-smokers aged 45 to 64 had a significant difference in incidence of mortality and myocardial infarction at 5 years and stroke at 1 and 5 years. ConclusionsOur analysis suggests male ever-smokers aged 45 to 65, male never-smokers aged 65 to 75, male never-smokers aged greater than 75, and female ever-smokers aged 65 or greater have a more than 1% prevalence of AAA and, therefore, may benefit from screening. Outcomes were significantly worse compared with well-matched controls in these groups.

Evaluation of aortic tortuosity as a negative predictor of abdominal aortic aneurysm rupture.

The maximal aortic diameter has been used as a key indication for whether to repair abdominal aortic aneurysms (AAAs). Aortic tortuosity has been proposed as another factor to consider. In the present study, we compared the degree of aortic tortuosity in ruptured AAAs with that of unruptured AAAs using computed tomography. We performed a retrospective review of a prospectively maintained database of patients who had undergone AAA repair from December 2014 to December 2019. Patients with a ruptured aneurysm (rAAA) were matched with patients with a nonruptured AAA (nrAAA) with the same maximal aneurysm diameter and age. The degree of aortic tortuosity, defined as the maximum lateral deviation from the aortic centerline, was measured on preoperative coronal computed tomography scans. During a 5-year period, 572 AAA cases were identified. The aortic tortuosity of the 25 rAAA cases was compared with that of a matched control group of 31 nrAAAs, selected by the same mean maximum diameter of 8.4cm and similar patient age. In the rAAA group, the mean age was 74.8years (84% men). In the nrAAA group, the mean age was 76.3years (88% men). The mean aortic tortuosity for the rAAA and nrAAA groups was 9.3± 7.9mm and 18.0± 11.2mm, respectively (P< .01). Greater aortic tortuosity was seen in the nrAAA cases compared with the rAAA cases at the same matched aneurysm size. Thus, aortic tortuosity might confer a reduced rupture risk. Further studies with larger cohorts are needed to verify this observation.

Association Between Blood Flow Pattern and Rupture Risk of Abdominal Aortic Aneurysm Based on Computational Fluid Dynamics

This study aimed to derive a novel classification of blood flow pattern in abdominal aortic aneurysms (AAA) based on computational fluid dynamics (CFDs), and to determine the predictive value of flow patterns in AAA rupture. This was an age and sex matched case control study. Cases were identified as patients who underwent emergency endovascular or open repair due to ruptured or AAA at risk of impending rupture. Controls were age and sex matched with patients with an AAA who were asymptomatic and had a confirmed unruptured AAA from computed tomography angiography images from the same period. Classification of blood flow pattern (type I: non-helical main flow channel with multiple vortices; type II: non-helical main flow channel with single vortices; and type III, helical main flow channel with helical vortices) and haemodynamic parameters (areas of low wall shear stress [AlowWSS], aneurysm pressure drop [Δ pressure], etc) were derived from CFD analyses. Multivariable regression was used to determine independent AAA rupture risk factors. The incremental discriminant and reclassification abilities for AAA rupture were compared among different models. Fifty-three ruptured and 53 intact AAA patients were included. Ruptured AAA showed a higher prevalence of type III flow pattern than intact AAA (60.4% vs. 15.1%; p < .001). Type III flow pattern was associated with a significantly increased risk of aneurysm rupture (odds ratio 10.22, 95% confidence interval 3.43 – 30.49). Among all predicting models, the combination of AAA diameter, haemodynamic parameters (AlowWSS or Δ pressure), and flow pattern showed highest discriminant abilities in both the overall population (c-index = 0.862) and subgroup patients with AAAs < 55 mm (c-index = 0.972). Compared with AAA diameter, adding the flow pattern could significantly improve the reclassification abilities in both the overall population (net reclassification index [NRI] = 0.321; p < .001) and the subgroup of AAAs < 55 mm (NRI = 0.732; p < .001). Type III flow pattern was associated with a significantly increased risk of AAA rupture. The integration of blood flow pattern may improve the identification of high risk aneurysms in both overall population and in those with AAAs < 55 mm.

Novel conformable stent-graft repair of abdominal aortic aneurysms with hostile neck anatomy: A single-centre experience.

Abdominal aortic aneurysms (AAAs) demonstrating hostile neck anatomy (HNA) are associated with increased perioperative risk and mortality. A number of these patients are not suitable for standard endovascular aneurysm repair (EVAR) and are high risk for open surgery. We present our experience with the first implantations in Scotland of a novel conformable aortic stent-graft designed to overcome some of the challenges of HNAs. From May 2018 to March 2022, 24 consecutive patients with non-ruptured AAAs demonstrating HNAs (neck length < 15mm, or angulation > 60°) were treated with GORE Excluder Conformable AAA endoprosthesis (CLEVAR) (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) at a Scottish vascular centre. We assessed clinical outcomes and technical success of CLEVAR during deployment, primary admission and the post-operative period at 3- and 12-month clinical follow-up alongside CT angiography. Twenty-four patients (20 males, mean age 75.6) were included. Primary technical success of proximal seal zones and CLEVAR deployment (no type 1/3 endoleaks, no conversion to open repair, AAA excluded and patient leaving theatre alive) was achieved in 100% of patients. All patients were alive and clinically stable at 3- and 12-month follow-up. There were five patients requiring re-intervention; at the 3-month follow-up, one patient (4.2%) developed a type 1b endoleak requiring graft limb extension, one patient developed a right common femoral artery dissection requiring open repair and one patient required a limb extension of the right iliac limb due to risk of developing a type 1b endoleak. At the 12-month follow-up, two patients required embolization of type 2 endoleaks and no patients demonstrated type 1 or type 3 endoleaks.Conclusions: In-hospital and post-operative 3- and 12-month clinical and angiographic outcomes demonstrate safety and efficacy with CLEVARs in treating unruptured AAAs with HNA. Further research involving larger heterogenous sample sizes is warranted to determine long-term clinical outcomes.

MiR-30c-1-3p targets matrix metalloproteinase 9 involved in the rupture of abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) can be fatal if ruptured, but there is no predictive biomarker. Our aim was to evaluate the prognostic potential of microRNAs (miRNAs/miRs) in an AAA mouse model and patients with unruptured AAA (URAAA) and ruptured AAA (RAAA). Among the 64 miRNAs differentially expressed in mice with AAA compared to control, miR-30c-1-3p, miR-432-3p, miR-3154, and miR-379-5p had high homology with human miRNAs. MiR-30c-1-3p plasma levels were significantly lower in patients with RAAA than in those with URAAA or control and tended to negatively correlate with the maximum aortic diameter (r =  −0.3153, P = 0.06109). MiR-30c-1-3p targeted matrix metalloproteinase (MMP)-9 mRNA through the coding region and downregulated its expression in vitro. MMP-9 plasma concentrations were significantly higher in the RAAA group than in the URAAA group (P < 0.001) and were negatively associated with miR-30c-1-3p levels (r =  −0.3671, P = 0.01981) and positively–with the maximal aortic diameter (r = 0.6251, P < 0.0001). The optimal cutoff values for MMP-9 expression and the maximal aortic diameter were 461.08 ng/ml and 55.95 mm, with areas under the curve of 0.816 and 0.844, respectively. Our results indicate that plasma levels of miR-30c-1-3p and MMP-9 may be candidate biomarkers of AAA progression.Key messagesDownregulation of miR-30c-1-3p expression and upregulation of its potential target MMP-9 are predictors of the devastation of AAA.Downregulation of miR-30c-1-3p expression and its downstream impact on MMP-9 have a potential on predicting the development and rupture of AAA.

Association Between Blood Flow Pattern and Rupture Risk of Abdominal Aortic Aneurysm Based on Computational Fluid Dynamics

This study aimed to derive a novel classification of blood flow pattern in abdominal aortic aneurysms (AAA) based on computational fluid dynamics (CFDs), and to determine the predictive value of flow patterns in AAA rupture. This was an age and sex matched case control study. Cases were identified as patients who underwent emergency endovascular or open repair due to ruptured or AAA at risk of impending rupture. Controls were age and sex matched with patients with an AAA who were asymptomatic and had a confirmed unruptured AAA from computed tomography angiography images from the same period. Classification of blood flow pattern (type I: non-helical main flow channel with multiple vortices; type II: non-helical main flow channel with single vortices; and type III, helical main flow channel with helical vortices) and haemodynamic parameters (areas of low wall shear stress [AlowWSS], aneurysm pressure drop [Δ pressure], etc) were derived from CFD analyses. Multivariable regression was used to determine independent AAA rupture risk factors. The incremental discriminant and reclassification abilities for AAA rupture were compared among different models. Fifty-three ruptured and 53 intact AAA patients were included. Ruptured AAA showed a higher prevalence of type III flow pattern than intact AAA (60.4% vs. 15.1%; p < .001). Type III flow pattern was associated with a significantly increased risk of aneurysm rupture (odds ratio 10.22, 95% confidence interval 3.43 - 30.49). Among all predicting models, the combination of AAA diameter, haemodynamic parameters (AlowWSS or Δ pressure), and flow pattern showed highest discriminant abilities in both the overall population (c-index= 0.862) and subgroup patients with AAAs < 55 mm (c-index= 0.972). Compared with AAA diameter, adding the flow pattern could significantly improve the reclassification abilities in both the overall population (net reclassification index [NRI]= 0.321; p < .001) and the subgroup of AAAs < 55 mm (NRI= 0.732; p < .001). Type III flow pattern was associated with a significantly increased risk of AAA rupture. The integration of blood flow pattern may improve the identification of high risk aneurysms in both overall population and in those with AAAs < 55 mm.

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio predict in-hospital mortality in symptomatic but unruptured abdominal aortic aneurysm patients.

Symptomatic but unruptured abdominal aortic aneurysm (AAA) is a potentially fatal disease since its etiopathogenesis, involving acute changes in the aortic wall, including inflammation, increasing the probability of impending rupture. The objective of the present study was to assess the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) in patients undergoing urgent symptomatic AAA repair. This was a retrospective study including 29 patients with symptomatic AAA repaired between 2011 and 2020. Both NLR and PLR were calculated on hospital admission prior to the intervention. The primary end point was in-hospital mortality, and the secondary end point included length of hospital stay and postoperative complications. In-hospital mortality rate was 10.3%. The discriminatory performance to predict the primary end point was very good both for PLR (area under the ROC curve [AUC]: 0.92 (95% confidence interval [CI]: 0.82-1.00; P=0.02) and NLR (AUC: 0.88 [95% CI: 0.75-1.00]; P=0.04). The best cutoff point to predict in-hospital mortality was 185 for PLR (100% sensitivity and 85% specificity) and 6.4 for NLR (100% sensitivity and 77% specificity). The most frequent postoperative complication was acute kidney failure (37.9%). Both elevated PLR as NLR were significantly associated with acute kidney failure and multiorgan failure in the immediate postoperative period (P<0.01). None of the two ratios was associated with length of hospital stay (P=NS). Both PLR and NLR are low-cost inflammatory markers widely available in every emergency department, with excellent performance to predict in-hospital mortality in patients undergoing symptomatic AAA repair. Patients with a PLR≥185 and/or an NLR≥6.4 could benefit from a "surveyed waiting conduct" improving the preoperative clinical condition prior to the intervention, or even considering endovascular repair.

[Relationship between hospital volumes and health outcomes: epidemiological evidence supporting the revision process of the Ministry of Health Decree no. 70 of 2 April 2015.]

In this perspective, this work intends to establish whether statistical correlations exist between volumes of activity and outcomes of hospital care. The scope is limited to several clinical conditions and therapeutic procedures for which specific indicators are provided by the National Healthcare Outcomes Programme (Programma Nazionale Esiti - PNE). For each condition or procedure, the analysis shows the volume-outcome relationship by hospital centre by means of the Levenberg-Marquardt algorithm (software: XLSTAT). The existence of breakpoints is assessed through the use of segmented models (software: "segmented" R-Package). The results show a statistical correlation for the following: acute myocardial infarction (breakpoint: 91 hospitalizations per year; 95% CI: 81-101; p<0.0001); repair of an unruptured abdominal aortic aneurysm (breakpoint: 69 procedures per year; 95% CI: 52-86; p=0.146); lung cancer (breakpoint: 96 procedures per year; 95% CI: 60-132; p<0.01); knee arthroplasty (breakpoint: 91 procedures per year; 95% CI: 51-131; p=0.484). Conversely, the statistical analysis did not allow to accurately highlight a breakpoint for the isolated aorto-coronary bypass, percutaneous transluminal coronary angioplasty and hip arthroplasty. These results represent a useful knowledge contribution to support the revision process of the above-mentioned Decree. As regards the procedures that may not be currently assessed through this statistical analysis method, literature data is referred to that confirm that the current regulatory thresholds are in the safe range.

Meta-analysis suggests statins reduce mortality after abdominal aortic aneurysm repair.

The necessity and efficacy of statin treatment for abdominal aortic aneurysm (AAA) remains controversial. This systematic review and meta-analysis was conducted to investigate the effects of statin therapy on the outcomes of patients with AAA. The Cochrane library, Embase, and MedLine were searched comprehensively to identify relevant cohort studies and randomized controlled trials. The primary outcomes included short- and long-term mortality after AAA repair, and secondary outcomes included the incidence of perioperative cardiovascular complications, sac shrinkage after endovascular aneurysm repair, and the growth rate of the aneurysms. Short-term mortality was defined as all-cause 30-day or in-hospital postoperative mortality. Long-term mortality was defined as the all-cause mortality at the end of follow-up period (≥1year). A random effects model was used to combine the results of included studies. Forest plots were created to show the pooled results of each outcome. One post hoc analysis of a randomized trial and 36 cohort studies (n= 134,290 patients) were included in this systematic review. The average score of included studies by Newcastle-Ottawa Scale was 7.76. Patients taking or not taking statin therapy were all diagnosed with unruptured AAA, and 59.9% of these patients were given statin therapy. Compared with statin nonusers, patients in statin therapy had significantly lower long-term mortality (odds ratio, 0.67; 95% confidence interval, 0.59-0.75; P< .001; I2= 71.7%), and short-term mortality after aneurysmal repair (odds ratio, 0.51; 95% confidence interval, 0.36-0.73; P< .001; I2= 81.4%). No significant difference was found between patients taking or not taking statin treatment on perioperative cardiovascular complications or sac shrinkage after endovascular aneurysm repair or growth rate of AAA under surveillance. These findings suggest that statin use is associated with a significant decrease in long- and short-term mortality in patients after AAA repair. Based on these results, statin therapy is worth being used in clinical practice for the management of AAA.

Vascular Surgery in Japan: 2016 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 treatment performed by vascular surgeon in Japan in 2016, 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 National Clinical Database (NCD), including the number of treatments and early results such as operative and hospital mortality.Results: In total 136,414 vascular treatments were registered by 1,070 institutions in 2016. 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 21,653, 17,560, 4,983, 2,557, 846, 54,462 and 34,353, respectively. In the field of aneurysm treatment, 19,144 cases of abdominal aortic aneurysm (AAA) including common iliac aneurysm were registered, and 60.3% were treated by endovascular aneurysm repair (EVAR). Among AAA cases, 1,714 (9.4%) cases were registered as ruptured AAA. The operative mortality of ruptured and unruptured AAA was 15.7%, and 0.6%, respectively. 35.9% of ruptured AAA were treated by EVAR, and the EVAR ratio was gradually increasing, but the operative mortality of open repair and EVAR for ruptured AAA was 15.8%, and 15.3%, respectively. Regarding chronic arterial occlusive disease, open repair was performed in 9,303 cases, including 1,329 distal bypasses to the crural or pedal artery, whereas endovascular treatment (EVT) was performed in 8,257 cases. The EVT ratio was gradually increased at 47.0%. The number of varicose vein treatment tremendously increased to 52,639, and 68.5% of the cases were treated by endovenous laser ablations (EVLA). Regarding other vascular operations, 32,779 cases of vascular access operations and 1,411 lower limb amputation surgeries were included.Conclusions: The number of vascular treatments increased since 2011, and the proportion of endovascular procedures increased in almost all field of vascular diseases, especially EVAR for AAA, EVT for chronic arterial occlusive disease, and EVLA for varicose veins. (This is a translation of Jpn J Vasc Surg 2021; 30: 23–41.)

Cold chain logistics: a possible mode of SARS-CoV-2 transmission?

<b>Objective:</b> To determine whether the improved outcome of a surgical procedure in high volume hospitals is specific to the volume of the same procedure. <b>Design and setting:</b> Analysis of secondary...

Convolutional Neural Network based Segmentation of Abdominal Aortic Aneurysms.

Abdominal aortic aneurysms (AAAs) are balloonlike dilations in the descending aorta associated with high mortality rates. Between 2009 and 2019, reported ruptured AAAs resulted in ~28,000 deaths while reported unruptured AAAs led to ~15,000 deaths. Automating identification of the presence, 3D geometric structure, and precise location of AAAs can inform clinical risk of AAA rupture and timely interventions. We investigate the feasibility of automatic segmentation of AAAs, inclusive of the aorta, aneurysm sac, intra-luminal thrombus, and surrounding calcifications, using 30 patient-specific computed tomography angiograms (CTAs). Binary masks of the AAA and their corresponding CTA images were used to train and test a 3D U-Net - a convolutional neural network (CNN) - model to automate AAA detection. We also studied model-specific convergence and overall segmentation accuracy via a loss-function developed based on the Dice Similarity Coefficient (DSC) for overlap between the predicted and actual segmentation masks. Further, we determined optimum probability thresholds (OPTs) for voxel-level probability outputs of a given model to optimize the DSC in our training set, and utilized 3D volume rendering with the visualization tool kit (VTK) to validate the same and inform the parameter optimization exercise. We examined model-specific consistency with regard to improving accuracy by training the CNN with incrementally increasing training samples and examining trends in DSC and corresponding OPTs that determine AAA segmentations. Our final trained models consistently produced automatic segmentations that were visually accurate with train and test set losses in inference converging as our training sample size increased. Transfer learning led to improvements in DSC loss in inference, with the median OPT of both the training segmentations and testing segmentations approaching 0.5, as more training samples were utilized.

Vascular Surgery in Japan: 2015 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 treatment performed by vascular surgeon in Japan in 2015, 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 National Clinical Database (NCD), including the number of treatments and early results such as operative and hospital mortality.Results: In total 124,299 vascular treatments were registered by 1,038 institutions in 2015. 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 22,041, 15,671, 4,779, 2,313, 857, 48,837, and 29,801, respectively. In the field of aneurysm treatment, 18,907 cases of abdominal aortic aneurysm (AAA) including common iliac aneurysm were registered, and 57.6% were treated by endovascular aneurysm repair (EVAR). Among AAA cases, 1,850 (9.8%) cases were registered as ruptured AAA. The operative mortality of ruptured and un-ruptured AAA was 16.0%, and 0.6%, respectively. 33.6% of ruptured AAA were treated by EVAR, and the EVAR ratio was gradually increasing, but the operative mortality of open repair and EVAR for ruptured AAA was 16.6%, and 14.5%, respectively. Regarding chronic arterial occlusive disease, open repair was performed in 8,230 cases, including 1,194 distal bypasses to the crural or pedal artery, whereas endovascular treatment (EVT) was performed in 7,441 cases. The EVT ratio was gradually increased at 47.4%. Venous treatment including 47,046 cases with varicose vein treatments and 531 cases with lower limb deep vein thrombosis were registered. Regarding other vascular operations, 29,801 cases of vascular access operations and 1,511 lower limb amputation surgeries were included.Conclusions: The number of vascular treatments increased since 2011, and the proportion of endovascular procedures increased in almost all field of vascular diseases, especially EVAR for AAA, EVT for chronic arterial occlusive disease, and endovenous laser ablation (EVLA) for varicose veins. (This is a translation of Jpn J Vasc Surg 2020; 29: 161–179.)