Treatment Of Abdominal Aortic Aneurysms Research Articles

276 Favorable Outcomes for Endovascular Aneurysm Repair with Aorto-Uni-Iliac (AUI) Stent Grafts for Treatment of Abdominal Aortic Aneurysms (AAA) by a Single Team in 8 Years at South Mersey Arterial (SMArt): A Tertiary Care Vascular Surgery Centre

Abstract Background Endovascular Aneurysm Repair (EVAR) is established procedure for management of both elective and ruptured abdominal aortic aneurysms (AAA). However, in several cases, standard EVAR with bilateral limb extension cannot be done due to complex anatomy or calcified contralateral iliac artery. In such cases AUI stent graft and Fem-Fem cross over is a feasible option. This study aims to assess the outcomes of AUI with or without fem-fem cross over performed in SMART centre over 8 years Method A retrospective study on patients who had repair of AAA using AUI between 2014-2022, with or without crossover. Demographic, procedural, and radiological data was collected through digital database. The outcomes were based on mode of admission, mortality rate, complications and patency rate of the graft at 2 years. Results A total of 28 patients had AUI between January 2014-January 2022. Median age was 79 years (59-94) with male predominance (85%). 50% of the patients presented with ruptured AAA, 46% had elective repair and 4% of patients presented with Acute limb ischaemia. 30-day mortality was found to be 21%. Local complications included endoleak, graft infection, groin bleeding, lymph leak and wound dehiscence and general complications included a predominance of HAP and cardiac issues. The patency rate was checked at 6 months, 1-2 years. 6-month patency of the graft was found to be 93%. Similarly, 1 and 2-year patency was also found to be 93% Conclusions AUI with or without Fem-Fem crossover is an acceptable alternative treatment modality for ruptured or non-ruptured AAAs despite involving an extra-anatomical bypass.

German nation-wide in-patient treatment of abdominal aortic aneurysm—trends between 2005 and 2019 and impact of the SARS-CoV-2 pandemic

PurposeAim of this study was to analyze hospitalizations due to ruptured and non-ruptured abdominal aortic aneurysms (rAAA, nrAAA) in Germany between 2005 and 2021 to determine long-term trends in treatment and the impact of the SARS-CoV-2 pandemic.Materials and MethodsFully anonymized data were available from the research data center (RDC) of the German Federal Statistical Office (Destatis). All German hospitalizations with the ICD-10 code “I71.3, rAAA” and “I71.4, nrAAA” in 2005 and 2010–2021 were analyzed.ResultsWe report data of a total of 202,951 hospitalizations. The number of hospitalizations increased from 2005 to 2019 (14,075 to 16,051, + 14.0%). The rate of open repair (OR) constantly decreased, whereas the rate of endovascular aortic repair (EVAR) increased until 2019. During the pandemic, the number of hospitalizations due to nrAAA dropped from 13,887 (86.5%) in 2019 to 11,278 (85.0%) in 2021. The strongest decrease of hospitalizations for AAA was observed during the first wave of the SARS-CoV-2-pandemic in spring 2020 (-25.5%).ConclusionOver the past decades, we observed an increasing number of hospitalizations due to AAA accompanied by a shift from OR to EVAR especially for nrAAA. During the lockdown measures due to the SARS-CoV-2-pandemic, a decrease in hospitalizations for nrAAA (but not for rAAA) was shown in 2020 and furthermore in 2021 with no rebound of treatment of nrAAA suggesting an accumulation of untreated AAA with a potentially increased risk of rupture.

Binding of Pentagalloyl Glucose to Aortic Wall Proteins: Insights from Peptide Mapping and Simulated Docking Studies.

Pentagalloyl glucose (PGG) is currently being investigated as a non-surgical treatment for abdominal aortic aneurysms (AAAs); however, the molecular mechanisms of action of PGG on the AAA matrix components and the intra-luminal thrombus (ILT) still need to be better understood. To assess these interactions, we utilized peptide fingerprinting and molecular docking simulations to predict the binding of PGG to vascular proteins in normal and aneurysmal aorta, including matrix metalloproteinases (MMPs), cytokines, and fibrin. We performed PGG diffusion studies in pure fibrin gels and human ILT samples. PGG was predicted to bind with high affinity to most vascular proteins, the active sites of MMPs, and several cytokines known to be present in AAAs. Finally, despite potential binding to fibrin, PGG was shown to diffuse readily through thrombus at physiologic pressures. In conclusion, PGG can bind to all the normal and aneurysmal aorta protein components with high affinity, potentially protecting the tissue from degradation and exerting anti-inflammatory activities. Diffusion studies showed that thrombus presence in AAAs is not a barrier to endovascular treatment. Together, these results provide a deeper understanding of the clinical potential of PGG as a non-surgical treatment of AAAs.

Evaluating the decision to use Fenestrated EVAR for the elective treatment of a complex AAA

An aneurysm is defined as a focal dilatation of all three walls of an artery wall. This can occur at any point in the arterial tree but most commonly presents as an abdominal aortic aneurysm (AAA), with a diameter of 50% greater than its normal size. The prevalence of AAAs is estimated to be between 1.2-7.6% in over 50 year olds in the UK, and it is sevenfold higher for men compared with women1. There is approximately a 1% mortality from ruptured AAAs, and as such current NHS guidelines recommend that all men over 65 are screened annually, a precedent supported by the Multicentre Aneurysm Screening Study (MASS)2. AAAs reaching 5.5cm in diameter require elective surgical repair, which can take the form of endovascular aneurysm repair (EVAR) or open surgical repair.

The choice of tactics for surgical treatment of abdominal aortic aneurysm in octogenarians

Currently, the treatment of abdominal aortic aneurysm does not pose significant difficulties, with modern cardiovascular surgery offering the possibility of both open and endovascular repair (EVAR) techniques. However, the personalized selection of the most optimal surgical intervention for each patient remains a relevant question. In some cases, one of the important factors influencing the choice of surgical method is the patient’s age and accompanying diseases. Abdominal aortic aneurysm is an age-related condition with a high risk of fatal outcomes. In our practice, we encountered a rare case of abdominal aortic aneurysm in an octogenarian woman with severe somatic status, poorly controlled arterial hypertension, and complex anatomical enlargement of the aneurysm. The question arose regarding the choice of optimal tactics and surgical treatment method. According to the MSCT, the diameter of the expansion was 67 mm, posing a 20% risk of rupture in the first year. In this clinical case, EVAR technique was unsuitable due to the anatomical features of the aneurysm, as the length of the neck in the infrarenal segment of the aorta was 2.5–3 cm, and the angle of inclination to the right exceeded 85°. Additionally, considering gender-specific factors, particularly female gender, indications for EVAR need to be carefully determined, as women have a higher likelihood of complications following the operation, as shown in several studies. After a detailed analysis of the re-evaluation results and assessment of surgical risk factors, we determined an individual surgical strategy and minimized risks, ultimately achieving a good outcome.

Status of diagnosis and therapy of abdominal aortic aneurysms.

Abdominal aortic aneurysms (AAAs) are characterized by localized dilation of the abdominal aorta. They are associated with several serious consequences, including compression of adjacent abdominal organs, pain, treatment-related financial expenditure. The main complication of AAA is aortic rupture, which is responsible for about 200,000 deaths per year worldwide. An increasing number of researchers are dedicating their efforts to study AAA, resulting in significant progress in this field. Despite the commendable progress made thus far, there remains a lack of established methods to effectively decelerate the dilation of aneurysms. Therefore, further studies are imperative to expand our understanding and enhance our knowledge concerning AAAs. Although numerous factors are known to be associated with the occurrence and progression of AAA, the exact pathway of development remains unclear. While asymptomatic at most times, AAA features a highly unpredictable disease course, which could culminate in the highly deadly rupture of the aneurysmal aorta. Current guidelines recommend watchful waiting and lifestyle adjustment for smaller, slow-growing aneurysms, while elective/prophylactic surgical repairs including open repair and endovascular aneurysm repair are recommended for larger aneurysms that have grown beyond certain thresholds (55 mm for males and 50 mm for females). The latter is a minimally invasive procedure and is widely believed to be suited for patients with a poor general condition. However, several concerns have recently been raised regarding the postoperative complications and possible loss of associated survival benefits on it. In this review, we aimed to highlight the current status of diagnosis and treatment of AAA by an in-depth analysis of the findings from literatures.

Regulation of Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 in Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a degenerative disease characterized by destruction and progressive expansion of the abdominal aortic wall. An AAA is typically defined as an enlargement of the abdominal aorta with diameter ≥3 cm or ≥50% greater than the suprarenal diameter. The pathological changes associated with AAA include inflammatory cell infiltration, extracellular matrix (ECM) destruction and remodeling, and vascular smooth muscle cell loss. The matrix metalloproteinase (MMP) family of proteins plays an important role in initiation and progression of AAA. Since understanding the regulation of MMP-2 and MMP-9 in AAA is essential for treatment of AAA, this review summarized the regulatory mechanisms of MMPs to provide a reference for exploring novel therapeutic approaches.

Decrease in Haemoglobin in Association with Aneurysm Volume Loss after Endovascular Repair of Abdominal Aortic Aneurysm.

Anaemia (low haemoglobin [Hb]) is well known to be associated with high mortality and adverse cardiac events following surgical treatment of abdominal aortic aneurysm (AAA). However, little is known about the relationship of AAA volume and Hb level alterations with endovascular repair of AAA. This study aimed to examine the changes in the Hb level and aneurysm volume before and after endovascular aneurysm repair (EVAR) for AAA and determine the relationship between the post-operative Hb level and the volume loss of AAA. This retrospective study reviewed patients with AAA who underwent EVAR between January 2020 and February 2021 at a tertiary medical centre. The clinical features and medical history of the patients were analysed. Alterations in the Hb level were recorded, and the AAA volume was calculated from computed tomography angiography images before and after EVAR to infer the association between the post-operative Hb level and alterations in AAA volume. Moreover, AAA volume, pre-operative Hb level and medical history were studied to identify the risk factors for anaemia 24 h after EVAR. A total of 74 patients (mean age, 67 7.9 years) were included in this study. The Hb level decreased significantly 24 h after EVAR, and the post-operative Hb level was negatively correlated with AAA volume loss (r = -0.252, p = 0.041). No relationship was observed between AAA volume loss and decrease in the Hb level (r = 0.072, p = 0.571) or between pre-operative AAA volume and decrease in the Hb level (r = 0.072, p = 0.566). Furthermore, 59.5% of the patients (n = 44) developed anaemia 24 h after EVAR. The odds ratio (OR) of anaemia 24 h after EVAR was 5.3 times higher in those with hypertension (OR, 5.304; 95% confidence interval [CI], 1.024-27.424) than in those without the condition. The pre-operative Hb level (or normal Hb level) was a protective factor (OR = 0.909; 95% CI, 0.853-0.969). The area under the receiver operating characteristic curve was 0.840. The post-operative Hb level declined significantly, and AAA volume loss contributed to it. Moreover, hypertension was identified to be a risk factor for anaemia 24 h after EVAR, and pre-operative Hb level was discerned to be a protective factor. The findings suggest that decrease in the Hb level in the early post-EVAR stage warrants the attention of surgeons, especially in patients with a history of hypertension or a low pre-operative Hb level.

Changes in renal-mesenteric duplex ultrasound velocities after fenestrated and branched endovascular aortic aneurysm repair

ObjectiveStenting of renal and mesenteric vessels may result in changes in velocity measurements due to arterial compliance, potentially giving rise to confusion about the presence of stenosis during follow-up. The aim of our study was to compare preoperative and postoperative changes in peak systolic velocity (PSV, cm/s) after placement of the celiac axis (CA), superior mesenteric artery (SMA) and renal artery (RAs) bridging stent grafts during fenestrated-branched endovascular aortic repair (FB-EVAR) for treatment of complex abdominal aortic aneurysms (AAA) and thoracoabdominal aortic aneurysms. MethodsPatients were enrolled in a prospective, nonrandomized single-center study to evaluate FB-EVAR for treatment of complex AAA and thoracoabdominal aortic aneurysms between 2013 and 2020. Duplex ultrasound examination of renal-mesenteric vessels were obtained prospectively preoperatively and at 6 to 8 weeks after the procedure. Duplex ultrasound examination was performed by a single vascular laboratory team using a predefined protocol including PSV measurements obtained with <60° angles. All renal-mesenteric vessels incorporated by bridging stent grafts using fenestrations or directional branches were analyzed. Target vessels with significant stenosis in the preoperative exam were excluded from the analysis. The end point was variations in PSV poststent placement at the origin, proximal, and mid segments of the target vessels for fenestrations and branches. ResultsThere were 419 patients (292 male; mean age, 74 ± 8 years) treated by FB-EVAR with 1411 renal-mesenteric targeted vessels, including 260 CAs, 409 SMAs, and 742 RAs. No significant variances in the mean PSVs of all segments of the CA, SMA, and RAs at 6 to 8 weeks after surgery were found as compared with the preoperative values (CA, 135 cm/s vs 141 cm/s [P = .06]; SMA, 128 cm/s vs 125 cm/s [P = .62]; RAs, 90 cm/s vs 83 cm/s [P = .65]). Compared with baseline preoperative values, the PSV of the targeted vessels showed no significant differences in the origin and proximal segment of all vessels. However, the PSV increased significantly in the mid segment of all target vessels after stent placement. ConclusionsStent placement in nonstenotic renal and mesenteric vessels during FB-EVAR is not associated with a significant increase in PSVs at the origin and proximal segments of the target vessels. Although there is a modest but significant increase in velocity measurements in the mid segment of the stented vessel, this difference is not clinically significant. Furthermore, PSVs in stented renal and mesenteric arteries were well below the threshold for significant stenosis in native vessels. These values provide a baseline or benchmark for expected PSVs after renal-mesenteric stenting during FB-EVAR.

Percutaneous treatment of abdominal aortic aneurysm and aortic valve stenosis with ‘staged’ EVAR and TAVR: a case series

Symptomatic aortic valve stenosis (AS) and abdominal aortic aneurysm (AAA) are critical clinical conditions, increasingly more prevalent with aging of the population. Calcific aortic stenosis is the most common structural cardiac disease in the elderly population, and medical management of severe aortic stenosis of the elderly population is associated with poor outcomes as compared to surgical treatment. Transcatheter aortic valve replacement (TAVR) is a treatment of choice in inoperable, often elderly, patients with symptomatic severe AS and in intermediate-to-high surgical risk patients. It is not yet clarified the incidence of AAA and its impact on procedural and clinical outcomes among patients undergoing TAVR. It is known that after AS resolution with aortic valve replacement or TAVR there is an increase in blood pressure that increases the risk of dissection or abdominal aortic aneurysm rupture if AAA repair is delayed. The purpose of this report is to describe the anatomical details and technical and procedural considerations when proposing totally endovascular strategies dedicated to the treatment of patients with AS and AAA.

3D-Ultrasound Based Mechanical and Geometrical Analysis of Abdominal Aortic Aneurysms and Relationship to Growth.

The heterogeneity of progression of abdominal aortic aneurysms (AAAs) is not well understood. This study investigates which geometrical and mechanical factors, determined using time-resolved 3D ultrasound (3D + t US), correlate with increased growth of the aneurysm. The AAA diameter, volume, wall curvature, distensibility, and compliance in the maximal diameter region were determined automatically from 3D + t echograms of 167 patients. Due to limitations in the field-of-view and visibility of aortic pulsation, measurements of the volume, compliance of a 60mm long region and the distensibility were possible for 78, 67, and 122 patients, respectively. Validation of the geometrical parameters with CT showed high similarity, with a median similarity index of 0.92 and root-mean-square error (RMSE) of diameters of 3.5mm. Investigation of Spearman correlation between parameters showed that the elasticity of the aneurysms decreases slightly with diameter (p = 0.034) and decreases significantly with mean arterial pressure (p < 0.0001). The growth of a AAA is significantly related to its diameter, volume, compliance, and surface curvature (p < 0.002). Investigation of a linear growth model showed that compliance is the best predictor for upcoming AAA growth (RMSE 1.70mm/year). To conclude, mechanical and geometrical parameters of the maximally dilated region of AAAs can automatically and accurately be determined from 3D + t echograms. With this, a prediction can be made about the upcoming AAA growth. This is a step towards more patient-specific characterization of AAAs, leading to better predictability of the progression of the disease and, eventually, improved clinical decision making about the treatment of AAAs.

Evaluation of false lumen occluders implanted in the abdominal aorta false lumen

ObjectiveManagement of postdissection thoracoabdominal aneurysms with a fenestrated and/or branched endograft (F/BEVAR) is associated with favorable outcomes. Treatment should include both true lumen endografting and false lumen occlusion (FLO). Favorable results have recently been reported for FLO in the false lumen of the thoracic aorta. The purpose of this study is to analyze the results of FLO of the abdominal aorta in patients treated for post dissection thoracoabdominal aneurysm. MethodsA multicenter retrospective analysis of prospective data of consecutive patients managed for post dissection thoracoabdominal aortic aneurysm from April 2019 to December 2022 with F/BEVAR associated with FLO in the abdominal false lumen was conducted. The STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) was followed. Baseline demographics, operative details, and early outcomes (mortality, length of stay) were recorded. Primary endpoints were technical and clinical success. FLO technical success was defined as complete occlusion of false lumen backflow above the FLO on completion angiogram. ResultsDuring the 3-year study, 23 patients were treated for post dissection thoracoabdominal aneurysm with F/BEVAR and the use of abdominal FLO. Twenty-one patients (91.3%) had received prior endovascular treatment. The technical and clinical success was 95.7%. The abdominal FLO had a technical success rate of 78.3%. The median diameter of the FLO was 34 mm. No patient died during the perioperative period, and one patient had spinal cord ischemia (4.3%) with partial recovery. Six patients (26.1%) required early reintervention. The median duration of hospitalization in the intensive care unit and overall was 1 day (interquartile range, 0-3 days) and 7.5 days (interquartile range, 2-22 days), respectively. During the mean follow-up of 9.9 ± 9.0 months, no patient died. False lumen occlusion was complete or partial in nine (39.1%) and nine (39.1%) patients, respectively. No aortic rupture occurred during follow-up. Maximum aortic diameter decreased in 48% and remained stable in 39% of cases. ConclusionsAbdominal aorta FLO during endovascular treatment of post dissection thoracic abdominal aortic aneurysm is associated with favorable outcomes. It offers an additional staging therapeutic option before extensive aorto-bi-iliac coverage, associated with low spinal cord ischemia rates. FLO also provides high rates of false lumen occlusion and false lumen remodeling during follow-up. Longer follow-up and larger cohorts are required to confirm these very promising early findings.

Assessment of heat transfer and the consequences of iron oxide (Fe3O4) nanoparticles on flow of blood in an abdominal aortic aneurysm

The present study is established on a simulation using CFD analysis in COMSOL. Blood acted as the base fluid with this simulation. The taken flow is been modeled as incompressible, unsteady, laminar and Newtonian fluid, which is appropriate at high rates of shear. The characteristic of flow of blood is been studied in order to determine pressure, velocity and temperature impact caused by an abdominal aortic aneurysm (AAA). This work employs nanoparticles of the Iron Oxide (Fe3O4) type. The CFD technique is utilized to evaluate the equations of mass, momentum, and energy. The COMSOL software is utilized to generate a normal element sized mesh. The findings of this study demonstrate that velocity alters through aneurysmal part of the aorta, that velocity is higher in a diseased segment, and that velocity increases before and after the aneurysmal region. For the heat transfer feature, the reference temperature and general inward heat flux is taken as 293.15K and 800W/m2. The nanoparticles altered blood's physical properties, including conductivity, dynamic viscosity, specific heat, and density. The inclusion of Iron Oxide (Fe3O4) nanoparticles managed to prevent overheating because taken nanoparticles have significant thermal conductivity. These findings will be extremely beneficial in the treatment of abdominal aortic aneurysm.

Elective Endovascular Aneurysm Repair (EVAR) for the Treatment of Infrarenal Abdominal Aortic Aneurysms of 5.0–5.5 cm: Differences between Men and Women

Background: There is significant debate regarding the existence of sex-related differences in the presentation, treatment, and outcomes of men versus women affected by abdominal aortic aneurysm (AAA). The purpose of this study is to compare endovascular aneurysm repair (EVAR) of infrarenal AAAs with the current sex-neutral 5.0–5.5 cm-diameter threshold for intervention between the two sexes. Methods: Retrospective review of consecutive cases from a single teaching institution over a period of five years of patients who had undergone elective EVAR for AAAs between 5.0 and 5.5 cm in diameter. Outcomes of interest were compared according to sex. Results: Ninety-four patients were included in the analysis, with a higher prevalence of men (53%). Females were older at the time of repair, 78 ± 5.1 years, versus 71.7 ± 7 years (p &lt; 0.01), and had higher incidence of underlying comorbidities, namely, arrhythmia, chronic kidney disease, and previous carotid revascularization. Women had higher incidence of immediate systemic complications (p = 0.021), post-operative AMI (p = 0.001), arrhythmia (p = 0.006), pulmonary oedema (p &lt; 0.001), and persistent renal dysfunction (p = 0.029). Multivariate analysis for post-operative factors associated to mortality and adjusted for sex confirmed that AMI (p = 0.015), arrhythmia (p = 0.049), pulmonary oedema (p = 0.015), persistent renal dysfunction (p &lt; 0.001), cerebral ischemia (p &lt; 0.001), arterial embolism of lower limbs (p &lt; 0.001), and deep-vein thrombosis of lower limbs (p &lt; 0.001) were associated to higher EVAR-related mortality; a higher incidence of post-operative AMI (p = 0.014), pulmonary edema (p = 0.034), and arterial embolism of lower limbs (p = 0.046) were associated to higher 30-days mortality. In females there was also a higher rate of suprarenal fixation (p = 0.026), insertion outside the instruction for use (p = 0.035), and a more hostile neck anatomy with different proximal aortic diameter (p &lt; 0.001) and angle (p = 0.003). Conclusions: A similar threshold of size of AAA for elective surgery for both males and females might not be appropriate for surgical intervention, as females tend to have worse outcomes. Further population-based studies are needed to guide on sex-related differences and intervention on AAA.

The relationship between computed tomography-derived body composition, systemic inflammation, and survival in patients with abdominal aortic aneurysm

ObjectivePatient selection and risk stratification for elective repair of abdominal aortic aneurysm (AAA), either by open surgical repair or by endovascular aneurysm repair, remain challenging. Computed tomography (CT)-derived body composition analysis (CT-BC) and systemic inflammation-based scoring systems such as the systemic inflammatory grade (SIG) appear to offer prognostic value in patients with AAA undergoing endovascular aneurysm repair. The relationship between CT-BC, systemic inflammation, and prognosis has been explored in patients with cancer, but data in noncancer populations are lacking. The present study aimed to examine the relationship between CT-BC, SIG, and survival in patients undergoing elective intervention for AAA. MethodsA total of 611 consecutive patients who underwent elective intervention for AAA at three large tertiary referral centers were retrospectively recruited for inclusion into the study. CT-BC was performed and analyzed using the CT-derived sarcopenia score (CT-SS). Subcutaneous and visceral fat indices were also recorded. SIG was calculated from preoperative blood tests. The outcomes of interest were overall and 5-year mortality. ResultsMedian (interquartile range) follow-up was 67.0 (32) months, and there were 194 (32%) deaths during the follow-up period. There were 122 (20%) open surgical repair cases, 558 (91%) patients were male, and the median (interquartile range) age was 73.0 (11.0) years. Age (hazard ratio [HR]: 1.66, 95% confidence interval [CI]: 1.28-2.14, P < .001), elevated CT-SS (HR: 1.58, 95% CI: 1.28-1.94, P < .001), and elevated SIG (HR: 1.29, 95% CI: 1.07-1.55, P < .01) were independently associated with increased hazard of mortality. Mean (95% CI) survival in the CT-SS 0 and SIG 0 subgroup was 92.6 (84.8-100.4) months compared with 44.9 (30.6-59.2) months in the CT-SS 2 and SIG ≥2 subgroup (P < .001). Patients with CT-SS 0 and SIG 0 had 90% (standard error: 4%) 5-year survival compared with 34% (standard error: 9%) in patients with CT-SS 2 and SIG ≥2 (P < .001). ConclusionsCombining measures of radiological sarcopenia and the systemic inflammatory response offers prognostic value in patients undergoing elective intervention for AAA and may contribute to future clinical risk predication strategies.

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.

Early outcomes of the Conformable endograft in severe neck angulation from the Triveneto Conformable Registry

ObjectiveThe study reports retrospective evaluation of early outcomes from a multicentric experience with the Excluder conformable endograft with active control system (CEXC Device) in the treatment of abdominal aortic aneurysms. Its design allows more flexibility, given by proximal unconnected stent rows and a bending wire within the delivery catheter enables control of proximal angulation. This study specifically focuses on the severe neck angulation (SNA) subgroup (≥60°). MethodsAll patients treated with CEXC Device in nine vascular surgery centers of Triveneto area (Northeast Italy) between January 2019 and July 2022 were enrolled prospectively and analyzed retrospectively. Demographic and aortic anatomical characteristics were evaluated. Endovascular aneurysm repair in SNA were selected for analysis. Major investigated outcomes were technical success, endoleaks, morbidity, mortality, and reinterventions at 30 days and during follow-up. Endograft migration and postoperative aortic neck angulation changes were also analyzed. ResultsA total of 129 patients were enrolled. An infrarenal angle of ≥60° was observed in 56 patients (43%) (SNA group) and their data analyzed. The mean patient age was 78.9 ± 5.9 years and median abdominal aortic aneurysm diameter 59 mm (range, 45-94 mm). Median aortic infrarenal neck length, angulation and diameter were 22 mm (range, 13-58 mm), 77° (range, 60°-150°), and 22.0 ± 3.5 mm respectively. Analysis revealed a technical success rate of 100% and perioperative major complication rate of 1.7%. Intraoperative and perioperative morbidity and mortality rates were 3.5% (one buttock claudication and one inguinal surgical cutdown) and 0%, respectively. No perioperative type I endoleaks were observed. The median follow-up was 13 months (range, 1-40 months). Five patients died during follow-up from aneurysm-unrelated causes. Two reinterventions occurred (3.5%): one conversion for a type IA endoleak and one sac embolization for a type II endoleak. Aneurysm sac shrinkage was observed in 15 patients (26%) and aneurysm stability in 35 patients (62%), respectively. Estimated freedom from reinterventions at 24 months was 92%. Aortic neck median postoperative angulation was 75° (range, 45°-139°). ConclusionsThe Triveneto Conformable Registry shows good early results of the CEXC device in severely angulated aortic infrarenal necks. These data need confirmation on longer follow-up and a wider cohort of patients to further increase endovascular aneurysm repair eligibility in SNA.

Mathematical analysis of unsteady blood flow through bifurcated abdominal aorta featured aneurysm

An abdominal aortic aneurysm (AAA) is a localized dilatation of abdominal aorta. This study investigates a 2-dimensional unsteady and laminar flow through a bifurcated artery with an aneurysm that is computationally and mathematically simulated using 3-dimensional geometry. The fluid used in this simulation is blood which is Newtonian for high shear rate. The computational technique is used to solve the equations that governs due to the flow. The flow of blood is analyzed with the assist of cut planes of pressure and velocity in the abdominal aortic aneurysm (AAA) for t=1s and t=4s. The pressure on the wall and complete velocity profile are also displayed with the assist of graphs. The streamlines are also shown with the help of graphs for t=1s and t=4s. The results can be used in the treatment of abdominal aortic aneurysm.

Increased plasma renin by vasodilators promotes the progression of abdominal aortic aneurysm.

Background: It is well-accepted that antihypertensive therapy is the cornerstone of treatment for abdominal aortic aneurysm (AAA) patients with hypertension. Direct-acting vasodilators were used in the treatment of hypertension by directly relaxing vascular smooth muscle but may have destructive effects on the aortic wall by activating the renin-angiotensin system axis. Their roles in AAA disease remain to be elucidated. In this study, we used hydralazine and minoxidil, two classical direct-acting vasodilators, to investigate their influence and potential mechanisms on AAA disease. Methods and results: In this study, we investigated the plasma renin level and plasma renin activity in AAA patients. Simultaneously, age and gender ratio-matched patients diagnosed with peripheral artery disease and varicose veins were selected as the control group using a ratio of 1:1:1. Our regression analysis suggested both the plasma renin level and plasma renin activity are positively associated with AAA development. In view of the well-established relationship between direct-acting vasodilators and increased plasma renin concentration, we established a porcine pancreatic elastase-infused AAA mouse model, followed by oral administration of hydralazine (250mg/L) and minoxidil (120mg/L) to investigate effects of direct-acting vasodilators on AAA disease. Our results suggested both hydralazine and minoxidil promoted the progression of AAA with increased aortic degeneration. Mechanistically, the vasodilators aggravated aortic inflammation by increased leukocyte infiltration and inflammatory cytokine secretion. Conclusion and relevance: The plasma renin level and plasma renin activity are positively associated with AAA development. Direct vasodilators aggravated experimental AAA progression, which raised cautionary concerns about their applications in AAA disease.

PRDM16 deficiency in vascular smooth muscle cells aggravates abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is usually asymptomatic until life-threatening complications occur, predominantly involving aortic rupture. Currently, no drug-based treatments are available, primarily due to limited understanding of AAA pathogenesis. The transcriptional regulator PR domain-containing protein 16 (PRDM16) is highly expressed in the aorta, but its functions in the aorta are largely unknown. By RNA-seq analysis, we found that vascular smooth muscle cell-specific (VSMC-specific) Prdm16-knockout (Prdm16SMKO) mice already showed extensive changes in the expression of genes associated with extracellular matrix (ECM) remodeling and inflammation in the abdominal aorta under normal housing conditions without any pathological stimuli. Human AAA lesions displayed lower PRDM16 expression. Periadventitial elastase application to the suprarenal region of the abdominal aorta aggravated AAA formation in Prdm16SMKO mice. During AAA development, VSMCs undergo apoptosis because of both intrinsic and environmental changes, including inflammation and ECM remodeling. Prdm16 deficiency promoted inflammation and apoptosis in VSMCs. A disintegrin and metalloproteinase 12 (ADAM12) is a gelatinase that can degrade various ECMs. We found that ADAM12 is a target of transcriptional repression by PRDM16. Adam12 knockdown reversed VSMC apoptosis induced by Prdm16 deficiency. Our study demonstrated that PRDM16 deficiency in VSMCs promoted ADAM12 expression and aggravates AAA formation, which may provide potential targets for AAA treatment.