Aneurysm Growth Rate Research Articles

Development and External Validation of [18F]FDG PET-CT-Derived Radiomic Models for Prediction of Abdominal Aortic Aneurysm Growth Rate

Objective (1): To develop and validate a machine learning (ML) model using radiomic features (RFs) extracted from [18F]FDG PET-CT to predict abdominal aortic aneurysm (AAA) growth rate. Methods (2): This retrospective study included 98 internal and 55 external AAA patients undergoing [18F]FDG PET-CT. RFs were extracted from manual segmentations of AAAs using PyRadiomics. Recursive feature elimination (RFE) reduced features for model optimisation. A multi-layer perceptron (MLP) was developed for AAA growth prediction and compared against Random Forest (RF), XGBoost, and Support Vector Machine (SVM). Accuracy was evaluated via cross-validation, with uncertainty quantified using dropout (MLP), standard deviation (RF), and 95% prediction intervals (XGBoost). External validation used independent data from two centres. Ground truth growth rates were calculated from serial ultrasound (US) measurements or CT volumes. Results (3): From 93 initial RFs, 29 remained after RFE. The MLP model achieved an MAE ± SEM of 1.35 ± 3.2e−4 mm/year with the full feature set and 1.35 ± 2.5e−4 mm/year with RFE. External validation yielded 1.8 ± 8.9e−8 mm/year. RF, XGBoost, and SVM models produced comparable accuracies internally (1.4–1.5 mm/year) but showed higher errors during external validation (1.9–1.97 mm/year). The MLP model demonstrated reduced uncertainty with the full feature set across all datasets. Conclusions (4): An MLP model leveraging [18F]FDG PET-CT radiomics accurately predicted AAA growth rates and generalised well to external data. In the future, more sophisticated stratification could guide individualised patient care, facilitating risk-tailored management of AAAs.

New Trends of Personalized Medicine in the Management of Abdominal Aortic Aneurysm: A Review.

Abdominal aortic aneurysm (AAA) is a significant vascular condition characterized by the dilation of the abdominal aorta, presenting a substantial risk of rupture and associated high mortality rates. Current management strategies primarily rely on aneurysm diameter and growth rates to predict rupture risk and determine the timing of surgical intervention. However, this approach has limitations, as ruptures can occur in smaller AAAs below surgical thresholds, and many large AAAs remain stable without intervention. This review highlights the need for more precise and individualized assessment tools that integrate biomechanical parameters such as wall stress, wall strength, and hemodynamic factors. Advancements in imaging modalities like ultrasound elastography, computed tomography (CT) angiography, and magnetic resonance imaging (MRI), combined with artificial intelligence, offer enhanced capabilities to assess biomechanical indices and predict rupture risk more accurately. Incorporating these technologies can lead to personalized medicine approaches, improving decision-making regarding the timing of interventions. Additionally, emerging treatments focusing on targeted delivery of therapeutics to weakened areas of the aortic wall, such as nanoparticle-based drug delivery, stem cell therapy, and gene editing techniques like CRISPR-Cas9, show promise in strengthening the aortic wall and halting aneurysm progression. By validating advanced screening modalities and developing targeted treatments, the future management of AAA aims to reduce unnecessary surgeries, prevent ruptures, and significantly improve patient outcomes.

Baseline Diameter Does Not Predict Growth Rate in a Presurgical Ascending Thoracic Aortic Aneurysm Population.

Patients with ascending thoracic aortic aneurysm are recommended to undergo routine imaging surveillance. Although maximal diameter is the primary metric of disease severity, recent American College of Cardiology/American Heart Association guidelines emphasize the importance of aortic growth in determining surgical candidacy and risk. As diameter increases, it is assumed that aortic growth rate accelerates because of increased wall tension; however, this relationship is poorly studied. We aim to investigate the relationship between ascending thoracic aortic aneurysm diameter and growth rate using vascular deformation mapping, a validated technique for 3-dimensional growth mapping with submillimeter accuracy. We retrospectively identified adult patients with ascending aortic dilation (≥4.0 cm) and serial gated computed tomography angiograms separated by ≥2 years, excluding confirmed heritable thoracic aortic disease. Ascending growth rate was defined as 90th percentile radial wall deformation by vascular deformation mapping. Maximal diameter measurements were derived from the baseline computed tomography angiogram, and aortic length and body size-adjusted indexes were calculated. Among 258 included patients (63.2% men; age of 63 years [interquartile range, 55-69 years]), mean±SD baseline diameter was 46.3±3.6 mm and median growth rate was 0.21 mm/year (interquartile range, 0.13-0.38 mm/year). No correlation was noted between growth rate and baseline diameter (r=0.02, P=0.74) or other aortic size metrics. On multivariate analysis, age was independently predictive of growth rate (β=-0.007, P=0.021), alongside weight (β=0.003, P=0.016) and the presence of moderate or severe aortic valve insufficiency (β=0.146, P=0.049). Maximal aortic diameter is not predictive of aortic growth rate, in this contemporary cohort of patients with sizes under current surgical thresholds (<55 mm).

Women Experience Higher Rates of Mortality Following Thoracic Endovascular Aneurysm Repair

ObjectivesThoracic endovascular aortic repair (TEVAR) and complex endovascular thoraco-abdominal aneurysm repair (cEVAR) has been increasingly adopted in the treatment of thoracic and thoracoabdominal aorta aneurysms, offering a less invasive approach for patients with appropriate anatomy. Women usually present with smaller aortic diameter. However, they usually have greater aneurysm growth rates. How sex can affect postoperative and short-term outcomes after TEVAR is not well reported. The aim of this study was to assess outcomes in female versus male patients undergoing TEVAR for treatment of thoracic and thoracoabdominal aneurysms in a Medicare-linked database. MethodsWe retrospectively reviewed patients undergoing TEVAR for thoracic and thoracoabdominal aneurysm repair in the Vascular Quality Initiative (VQI) Vascular Implant Surveillance and Interventional Outcomes Network (VISION) database from 2003 to 2018. Patients were divided into males and females. Patients presented with ruptured aneurysm were excluded from the analysis. Postoperative outcomes included in-hospital stroke, myocardial infarction (MI), spinal cord ischemia, and 30-day mortality. One-year outcomes included mortality, aneurysmal rupture, and reintervention. Postoperative outcomes were assessed using multivariable logistic regression analysis and one-year outcomes were evaluated using Kaplan Meier Survival and Cox regression analyses. ResultsA total of 3,058 males and 1,843 females were available for the analysis. Female patients had smaller median aortic diameter, were more likely to be black, with chronic obstructive pulmonary disease, and chronic kidney disease, and to be symptomatic on presentation. Male patients were more likely to be on preoperative medications such as aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, P2Y12 antagonists, and anticoagulants. After adjusting for potential confounders, female gender was associated with double the risk of in-hospital stroke (OR: 2.3, 95%CI ((1.5-3.7), P<0.001) and 80% increase in 30-day mortality (OR: 1.8, 95%CI (1.3-2.6), P=0.001). At one year, female gender was associated with a higher risk of mortality (HR: 1.2, 95%CI (1.05-1.4), P=0.011). There was a trend towards higher risk of reintervention (HR: 1.2, 95%CI (0.97-1.6), P=0.079). ConclusionsMortality after TEVAR seems to be higher in female patients at 30 days and up to one year of follow-up. Female patients also face a two times higher risk of in-hospital stroke. Future studies with a larger female population should aim to identify and potentially ameliorate the factors associated with these unfavorable outcomes in females.

Effects of paroxetine, a P2X4 inhibitor, on cerebral aneurysm growth and recanalization after coil embolization: the NHO Drug for Aneurysm Study.

Rupture of cerebral aneurysms has a poor prognosis, and growing aneurysms are prone to rupture. Although the number of coil embolization procedures is increasing worldwide, they are more prone to recurrence than clipping surgeries. However, there is still no drug that prevents aneurysm growth or recanalization after coil embolization. The authors have previously focused on the role of hemodynamics in cerebral aneurysm development and reported that inhibition of the P2X4 purinoceptor, by which vascular endothelial cells sense blood flow, reduced the induction and growth of aneurysms in an animal model. In this study, the authors investigated the effects of paroxetine, a P2X4 inhibitor also used as an antidepressant, on aneurysm growth and recanalization after endovascular coiling. Using the J-ASPECT Study registry, the largest comprehensive reimbursement database system for acute stroke inpatient care in Japan, the authors searched for patients incidentally taking paroxetine who were registered in the decade 2010-2019 with an unruptured cerebral aneurysm or who underwent aneurysm coiling. They calculated the growth incidence and growth rate by the person-year method and the odds ratio for recanalization within 1 year after coiling and statistically compared to controls. Seventy-eight stroke facilities participated, and 275 patients were identified as potentially eligible. Thirty-seven patients with unruptured aneurysms and 38 after coil embolization met all eligibility criteria. They were compared with 396 control cases of unruptured aneurysms and 308 coil-placement controls. Multivariate analysis showed that paroxetine significantly reduced the incidence of aneurysm growth (number of cases with growth/person/year; incidence rate ratio [IRR] 0.24, 95% CI 0.05-0.66; p = 0.003) and the growth rate (total increase in maximum diameter in millimeters/person/year; IRR 0.57, 95% CI 0.28-0.98; p = 0.04). Paroxetine also significantly reduced the odds of recanalization in the year after coiling (OR 0.21, 95% CI 0.05-0.95; p = 0.04). The authors then performed propensity score matching to reduce bias due to imbalances in patient characteristics between the two groups; the outcome confirmed that paroxetine significantly reduced aneurysm growth incidence (IRR 0.02, 95% CI 0.008-0.05; p < 0.0001) and growth rate (IRR 0.03, 95% CI 0.01-0.06; p < 0.0001) and the 1-year recanalization (OR 0.18, 95% CI 0.03-0.99; p = 0.04). This observational cohort study suggests that P2X4 inhibitors such as paroxetine may be clinically applicable as prophylaxis against aneurysm rupture and postoperative recanalization.

Rate of Ascending Aortic Enlargement in a Large Echocardiographic Cohort: Associated Risk Factors and Adverse Aortic Events

Understanding ascending aortic aneurysm growth and associated risk factors is critical to advising appropriate echocardiographic follow-up intervals for patients. This study aimed to identify aortic aneurysm growth rate on serial echocardiograms as well as the clinical and demographic variables that contribute to baseline aortic size and subsequent aortic growth. Patients identified with ascending aortic aneurysm and undergoing serial echocardiograms within five years were evaluated. Ascending aortic size was measured as part of routine echocardiogram exams. Clinical and demographic variables including aortic valve type (trileaflet, bicuspid or prosthetic) were evaluated for association with baseline aortic size as well as with aortic progression rate. Clinical events including aortic dissection, elective or emergent surgical repair were recorded. 3639 patients were identified, (78% males, median age of 69 years, 175 (4.8%) with bicuspid valve, and 206 (5.6%) with prior aortic valve replacement (AVR). Patients with larger aorta at baseline were older with higher tobacco use and prior prosthetic valves. Over a mean of 2.4 years, aortic growth was observed and differed by valve type (trileaflet valve: 0.08 mm/year , bicuspid valve: 0.4 mm/year , p<0.001). In six patients who developed aortic dissection the estimated average annual growth rate was 0.98 mm/year. In a large echo cohort, aortic aneurysm growth rate was 0.08 mm/year though higher in those with bicuspid valves ( 0.4 mm/ year), but initial aortic size did not correlate with change in the aortic progression rate. This data may help inform recommended echocardiographic surveillance intervals.

Metformin Improves the Function of Abdominal Aortic Aneurysm Patient-Derived Aortic Smooth Muscle Cells

Type 2 diabetes mellitus (T2DM) is a cardiovascular risk factor. Paradoxically, a decreased risk of abdominal aortic aneurysm (AAA) presence and growth rate is described among patients with T2DM, associated with metformin use. This study aimed to investigate the effect of metformin on AAA patient derived aortic smooth muscle cell (SMC) function. Aortic biopsies were obtained from patients with AAA (n = 21) and controls (n = 17) during surgery. The SMCs of non-pathological aortic controls, non-diabetic patients with AAA, and diabetic patients with AAA were cultured from explants and treated with or without metformin. The SMC contractility was measured upon ionomycin stimulation, as well as metabolic activity, proliferation, and migration. Then, mRNA and protein expression of markers for contraction, metabolic activity, proliferation, and inflammation were measured. The mRNA expression of KLF4 and GYS1, genes involved in metabolic activity, differed between the SMCs from non-diabetic and diabetic patients with AAA before metformin stimulation (p < .041). However, the effect of metformin on the various SMC functions was similar between non-diabetic and diabetic patients with AAA. Upon stimulation, metformin increased the contractility of AAA patient SMCs (p = .001). The mRNA expression of smoothelin, a marker for the contractile phenotype, increased in the SMCs of patients with AAA after treatment with metformin (p = .006). An increase in metabolic activity (p < .001) and a decrease in proliferation (p < .001) and migration were found in the SMCs of controls and patients with AAA with metformin. Increased mRNA expression of PPARγ, a nuclear receptor involved in mitochondrial biogenesis (p < .009), and a decrease in gene expression of Ki-67, a marker for proliferation (p < .005), were observed. Gene expression of inflammation markers MCP-1 and IL-6, and protein expression of NF-κB p65 decreased after treatment with metformin in patients with AAA. This study found that metformin increases contractility and metabolic activity, and reduces proliferation, migration, and inflammation in aortic SMCs in vitro.

Surgery versus surveillance for ascending aortic aneurysms in elderly patients

BackgroundWhether elderly patients with aortic root or ascending aortic aneurysm (ATAA) would benefit from the new surgical size threshold of 5.0 cm is unknown. This study aimed to evaluate the natural history of ATAA in elderly patients and to compare long-term outcomes of those who underwent initial surveillance versus surgery. MethodsPatients age ≥75 years with an ATAA ≥40 mm were categorized into 2 groups: initial surgery and initial surveillance. The primary outcome was all-cause mortality; Kaplan-Meier curves were plotted for survival. A multivariable Cox proportional hazard regression model was used to identify independent predictors of long-term mortality. ResultsThe study series comprised 300 patients, including 58 who underwent initial surgery and 242 who received surveillance between July 2010 and September 2022. In the surveillance cohort, the mean aneurysm growth rate was 0.10 cm/year. Comparing surveillance to surgery, at 8 years there was no difference in survival (mean, 77.8 ± 3.4% vs 71.8 ± 9.6%; P = .65). For 116 patients with an initial aneurysm diameter ≥5.0 cm, there was no difference in survival between the 2 groups at 8 years (76.5 ± 7.0% vs 68.4 ± 11.3%; P = .20). Larger body surface area (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.09-1.90; P = .01) and history of smoking (HR, 2.25; 95% CI, 1.27-3.98; P = .01) were identified as predictors of long-term mortality. ConclusionsIn our series of elderly patients with ATAA, there was no difference in 8-year survival between initial surveillance and surgical management, with a high competing risk of nonaortic mortality. Surveillance may be a reasonable alternative to surgery for selected older adults with ATAA <5.5 cm.

Metformin Use and Long-term Outcomes Including Aneurysm Sac Dynamics Following EVAR for Infrarenal Abdominal Aortic Aneurysm: "A Retrospective Study".

Metformin, widely used for the treatment of diabetes mellitus (DM), has shown potential for inhibiting abdominal aortic aneurysm (AAA) growth by reducing extracellular matrix remodeling and inflammation. However, its influence on clinical outcomes and aneurysm sac dynamics after endovascular aneurysm repair (EVAR) remains uncertain. This retrospective study aims to explore the effects of metformin on long-term outcomes following EVAR. Patients who underwent elective standard EVAR for infrarenal AAA at a single academic Dutch hospital from 2000 to 2022 were included. We collected baseline patient demographics, comorbid conditions, anatomical and operative characteristics, and 30-day postoperative events. Metformin use was defined as using it preceding EVAR. The primary outcome, the postoperative aneurysm sac volume over time, was investigated using linear mixed-effects modeling. The secondary outcomes, 8-year all-cause mortality and freedom from graft-related events, were evaluated using Kaplan-Meier methods. We analyzed 685 patients, including 634 (93%) non-metformin users and 51 (7%) metformin users. The median follow-up period was similar (4.0 years [IQR=1.5, 6.5] vs 5.0 years [IQR=2.0, 8.0]; p=0.091). Patients on metformin had a preoperative aneurysm sac volume of 153 cc (IQR=114, 195) compared with 178 cc (IQR=133, 240) for non-metformin patients (p=0.054). At 30 days post-EVAR, metformin patients had a comparable mean aneurysm sac volume compared with non-metformin patients (metformin: -19.4 cc [95% confidence interval [CI]: -47.4, 8.5]; p=0.173). The effect of metformin on aneurysm growth over time was not significant (-3.9 cc/year; [95% CI: -22.7, 14.9]; p=0.685). Following risk-adjusted analysis, metformin use was associated with similar rates of all-cause mortality (metformin vs no metformin: 50% vs 44%; hazard ratio [HR]=1.11, 95% CI: 0.66, 1.88; p=0.688) and freedom from graft-related events (metformin vs no metformin: 63% vs 66%; HR=1.82, 95% CI: 0.98, 3.38; p=0.059). Although metformin use may reduce preoperative AAA growth, it does not seem to influence overall/long-term post-EVAR AAA sac dynamics, all-cause mortality, or freedom from graft-related events. These findings suggest that the potential protective effect of metformin on AAA may not be sustained after EVAR. Further prospective studies are needed to investigate the mechanisms underlying the potential role of metformin in AAA management following EVAR. There is currently no approved pharmacological treatment available to slow the abdominal aortic aneurysm (AAA) growth rate and reduce the related risk of rupture. In our retrospective analysis including 685 patients undergoing EVAR for infrarenal AAA, we found that metformin use was not associated with improved post-EVAR outcomes, such as a reduction of aneurysm sac volume over time, eight-year all-cause mortality, or freedom of graft-related events. These findings suggest that the potential protective effect of metformin on AAA may not be sustained after EVAR and underscore the need for ongoing research into this area.

Factors that Influence Growth Rates of Abdominal Aortic Aneurysms. Analysis of a Mexican Cohort.

Abdominal Aortic Aneurysms (AAA) growth remains a process not fully understood. The objective of this study was to analyze risk factors associated with changes in AAA diameter in a Mexican cohort. An observational study in which we analyzed the entirely of patients in which an AAA was reported in a Computed Tomography (CT) study from 2014 to 2021 who had a follow-up CT. We divided them by groups depending on the diagnosis of type 2 diabetic mellitus and pharmacological history (diabetic vs non-diabetic, metformin vs non-metformin intake and statin vs non-statin intake). We compared pre and post follow-up AAA diameters using paired t-tests. A multivariate analysis was performed in order to identify independent variables associated with an increased growth rate. Statistical analysis was performed on Stata 17. During the studied period 72 (39.77%) patients had a follow-up CT. Mean age was 75years (±9.05) and 52 (72.22%) were men. When comparing infra-renal largest diameter through time based on metformin intake, a significant difference was found only in the metformin non-intake group (42.05 ± 12.54 vs45.34 ± 12.06 [P = 0.02]), in contrast the metformin intake group measures were non-significantly different (36.13 ± 7.04 vs 37.00 ± 4.51; P = 0.57) through follow-up. In the multivariate analysis AAA largest diameter at diagnosis correlated with significantly increased growth rate (coeff = 0.06, P < 0.05). AAA diameters appear to change through time in a non-linear pattern influenced by different epidemiological and clinical factors. Metformin intake appears to promote a stability in AAA diameter growth in our studied population.

Soluble glycoprotein VI predicts abdominal aortic aneurysm growth rate and is a novel therapeutic target

AbstractA common feature in patients with abdominal aortic aneurysms (AAAs) is the formation of a nonocclusive intraluminal thrombus (ILT) in regions of aortic dilation. Platelets are known to maintain hemostasis and propagate thrombosis through several redundant activation mechanisms, yet the role of platelet activation in the pathogenesis of AAA-associated ILT is still poorly understood. Thus, we sought to investigate how platelet activation affects the pathogenesis of AAA. Using RNA sequencing, we identified that the platelet-associated transcripts are significantly enriched in the ILT compared with the adjacent aneurysm wall and healthy control aortas. We found that the platelet-specific receptor glycoprotein VI (GPVI) is among the top enriched genes in AAA ILT and is increased on the platelet surface of patients with AAAs. Examination of a specific indicator of platelet activity, soluble GPVI (sGPVI), in 2 independent cohorts of patients with AAAs is highly predictive of an AAA diagnosis and associates more strongly with aneurysm growth rate than D-dimer in humans. Finally, intervention with the anti-GPVI antibody (JAQ1) in mice with established aneurysms blunted the progression of AAA in 2 independent mouse models. In conclusion, we show that the levels of sGPVI in humans can predict a diagnosis of AAA and AAA growth rate, which may be critical in the identification of high-risk patients. We also identify GPVI as a novel platelet-specific AAA therapeutic target, with minimal risk of adverse bleeding complications, for which none currently exists.

Sex-dependent characteristics and outcomes after clipping of unruptured intracranial aneurysms: a multicenter propensity score-matched study.

Disparities in the epidemiology and growth rates of aneurysms between the sexes are known. However, little is known about sex-dependent outcomes after microsurgical clipping of unruptured intracranial aneurysms (UIAs). The aim of this study was to examine sex differences in characteristics and outcomes after microsurgical clipping of UIAs and to perform a propensity score-matched analysis using an international multicenter cohort. This retrospective cohort study involved the participation of 15 centers spanning four continents. It included adult patients who underwent clipping of UIAs between January 2016 and December 2020. Patients were stratified according to their sex and analyzed for differences in morbidities and aneurysm characteristics. Based on this stratification, female patients were matched to male patients in a 1:1 ratio with a caliper width of 0.1 using propensity score matching. Endpoints included postoperative complications, neurological performance, and aneurysm occlusion at discharge and 24 months after clip placement. A total of 2245 patients with a mean age of 57.3 (range 20-87) years were included. Of these patients, 1675 (74.6%) were female. Female patients were significantly older (mean 57.6 vs 56.4 years, p = 0.03) but had fewer comorbidities. Aneurysms of the internal carotid artery (7.1% vs 4.2%), posterior communicating artery (6.9% vs 1.9%), and ophthalmic artery (6.0% vs 2.8%) were more commonly treated surgically in females, while clipping of aneurysms of the anterior communicating artery was more frequent in males (17.0% vs 25.3%; all p < 0.001). After propensity score matching, female patients were found to have had significantly fewer pulmonary complications (1.4% vs 4.2%, p = 0.01). However, general morbidity (24.5% vs 25.2%, p = 0.72) and mortality (0.5% vs 1.1%, p = 0.34), as well as neurological performance (p = 0.58), were comparable at discharge in both sexes. Lastly, rates of aneurysm occlusion at the time of discharge (95.5% vs 94.9%, p = 0.71) and 24 months after surgery (93.8% vs 96.1%, p = 0.22) did not significantly differ between male and female patients. Despite overall differences between male and female patients in demographics, comorbidities, and treated aneurysm location, sex did not relevantly affect surgical performance or perioperative complication rates.

Abstract 2008: Characterizing Changes In Abdominal Aortic Aneurysm Principal Wall Strain Using Ultrasound Elastography

Pressure-normalized aortic principal wall strain (ep+/pp, %/mmHg) is a biomechanical parameter for abdominal aortic aneurysm (AAA) stability correlated with aneurysm growth rate. We hypothesized that ep+/pp decreases as AAAs degenerate. This study aimed to characterize ep+/pp change over time using ultrasound elastography (USE). Axial ultrasound images of patient AAAs were collected at two consecutive clinic visits. The USE algorithm applied a finite element mesh over the aneurysm wall at the point of maximum diameter. A custom image-registration protocol tracked frame-to-frame displacement fields of the images over one cardiac cycle to calculate maximum ep+/pp (Fig 1). Clinical data were collected from patient records. The cohort was separated by index ep+/pp terciles. Thirty-one patients with a mean age of 71.7 ± 10.1 at index visit were included, with follow-up imaging at an interval of 7.1 ± 3.4 months. For the cohort, maximum ep+/pp decreased from 2.3 ± 1.0 %/mmHg to 2.0 ± 0.9 %/mmHg (p=0.08), and average AAA diameter increased from 4.4 ± 0.6 cm to 4.5 ± 0.7 cm (p=0.04). The “high-strain” tercile was associated with a strain reduction of -1.7 ± 0.8 %/mmHg, compared to “low” (0.1 ± 1.0 %/mmHg, p&lt;0.01) and “intermediate” (-0.4 ± 0.5 %/mmHg, p=0.04) terciles (Fig 2). There was no difference in AAA growth or rupture between terciles. The present findings indicate that AAA ep+/pp at baseline predicts the degree of ep+/pp decrease over time. These data suggest that biomechanical changes in the aortic wall related to aneurysmal degeneration can be quantized by a novel ultrasound technique. Research correlating these results with histopathologic AAA remodeling may inform monitoring.

Natural history and growth rate of intracranial aneurysms in Loeys-Dietz syndrome: implications for treatment.

Loeys-Dietz syndrome (LDS) is a heritable aortopathy associated with craniofacial abnormalities and dilatation and dissection of the aorta and its branches, as well as increased risk for intracranial aneurysms (ICAs). Given the rarity of the disease, the authors aimed to better define the natural history and role for the treatment for ICAs in these patients. The medical records of 83 patients with LDS were retrospectively reviewed to obtain clinical and genetic history and vascular imaging of the aorta, aortic branches, and intracranial vessels. Serial radiology reports and cervical and intracranial vascular images were reviewed to determine presence, location, and size of ICAs. In total, 55 patients (66.3%) had at least two screening intracranial vascular examinations, and 19 (22.9%) had at least 1 ICA detected. Aneurysms were typically small (mean ± SD 3.2 ± 1.8 mm). ICAs were most often located in the cavernous carotid, followed by the ophthalmic and anterior cerebral artery vessels. The rate of ICA growth was 0.43 ± 0.53 mm/year, similar to that of the general population. Three patients underwent intervention for an ICA, with 1 procedure complicated by stroke and resulting in transient hemiparesis. Several illustrative cases detail the authors' experience with ICA growth, de novo aneurysm formation, and ICA intervention in this rare patient population. ICAs in patients with LDS are common, are frequently small, and have a growth rate similar to that of unruptured ICAs in the general population. More aggressive or earlier intervention for asymptomatic ICAs identified in LDS patients compared with the general population is likely unwarranted based on the authors' experience at their institution.

The Natural History of Splenic Artery Aneurysms: Factors That Predict Aneurysm Growth

PurposeTo examine the natural history of splenic artery aneurysms (SAAs) at a single institution and assess the effect of patient factors and aneurysm characteristics on aneurysm growth. Materials and MethodsThis single-center retrospective study included patients with SAAs who underwent serial imaging over 30 years (1990–2020). Data regarding patient demographics and aneurysm characteristics were collected. The variables contributing to aneurysm growth were assessed using nonparametric tests for continuous variables and chi-square test for categorical variables. Multivariable linear regression was performed using aneurysm growth rate as a continuous dependent variable. ResultsA total of 132 patients were included in this study. The median maximum diameter of the SAAs was 15.8 mm (range, 4.0–50.0 mm). Growth over time was observed in 39% of the aneurysms, whereas the remaining 61% were stable in size. Of aneurysms that increased in size, the median aneurysm growth rate was 0.60 mm/y (range, 0.03–5.00 mm/y). Maximum aneurysm diameter of >2 cm and the presence of >50% mural thrombus were significant positive predictors for aneurysm growth (P = .020 and P = .022, respectively). Greater than 50% rim calcification was a significant negative predictor for aneurysm growth (P = .009) in multivariate analysis. ConclusionsA larger baseline SAA size, presence of mural thrombus, and lack of rim calcification are associated with increased aneurysm growth rate.

Can Biomarkers and PET Imaging Predict Abdominal Aortic Aneurysm Growth Rate?

Background: Abdominal aortic aneurysm (AAA) is a life-threatening condition due to the risk of aneurysm growth and rupture. Biomarkers linked to AAA pathogenesis are attractive candidates for AAA diagnosis and prognosis. The aim of this study was to assess circulating biomarkers levels relationship with PET imaging positivity and their predictive value in AAA growth rate. Methods: A total of 164 patients with AAA had whole body [18F]FDG PET/CT examination and blood drawn for biomarkers analysis at inclusion. Of these, 121 patients had at least one follow-up imaging assessment for AAA progression. Median (quartiles) imaging follow-up period was 32.8 months (15.2-69.6 months). Results: At baseline, PET was visually positive in 28 (17%) patients. Among PET+ patients, female proportion was higher compared to PET-patients (respectively, n = 6, 21.4% vs. n = 11, 8.1%, p = 0.046). Biomarkers of inflammation (CRP, CCL18), of proteolytic activity (MMP9), of extracellular matrix, and calcification regulation (OPN, OPG) were all significantly increased in PET+ patients (p < 0.05). During follow-up, rapid AAA growth (increase in size ≥ 1 cm per year) was observed in 36 (29.8%) patients and several biomarkers (CRP, MMP9, OPN, and OPG) were increased in those patients compared to patients without rapid growth (p < 0.05). Conclusions: Although PET positivity at baseline was not associated with rapid growth, CRP levels showed a significant association.

Evaluating growth patterns of abdominal aortic aneurysms among women

ObjectiveThough initially protected from vessel dilation by estrogen, women may experience rapid abdominal aortic aneurysm (AAA) growth post-menopause. The rate of growth has been poorly defined in prior literature. Here, we describe aneurysm growth in a cohort of women found through an AAA screening program. MethodsWomen with AAAs were retrospectively identified. Aortic imaging was reviewed, and measurements of maximum transverse and anterior-posterior diameters were completed. Growth was stratified by the type of aortic pathology (fusiform aneurysm, aortic ectasia, dissection with aneurysmal degeneration, saccular aneurysm) as well as size category (<3 cm, 3.0-3.9 cm, 4.0-4.9 cm, ≥5.0 cm) at diagnosis. ResultsA cohort of 488 women was identified; 286 had multiple scans for review. The mean age of the entire cohort was 75 ± 9.9 years. Stratified by type of pathology, the mean age was 76 ± 8.9 years in patients with a fusiform AAA, 74 ± 9.8 years in ectasia, 65 ± 13.7 years in dissection, and 76 ± 5.6 years in saccular aneurysms. The maximum growth was highest in women with fusiform AAAs, followed by dissection, ectasia, and saccular pathology (9.7 mm, 7.0 mm, 3.0 mm, and 2.2 mm, respectively; P < .001). Comparing mean growth by year, the highest mean growth was in fusiform AAAs (3.6 mm vs 1.75 mm in dissection; P < .001). The Shapiro-Wilk test demonstrated that mean growth per year was non-normally distributed with a right skew. Stratified by aortic diameter at the time of diagnosis, mean growth/year increased with increasing size at diagnosis in fusiform AAAs and dissection (0.91 mm for <3 cm, 2.34 mm for 3.0-3.9 cm, 2.49 mm for 4.0-4.9 mm, and 6.16 mm for ≥5.0 cm in patients with fusiform AAAs vs 0.57 mm, 0.94 mm, 1.87 mm, and 2.66 mm, respectively, for patients with dissection). Smoking history was associated with a higher mean growth/year (2.6 mm vs 3.3 mm; P < .001). Conversely, patients with a family history of AAA had a lower mean growth/year (3.2 mm vs 1.5 mm; P < .001). ConclusionsThe rate of aneurysm growth in women varies based on pathology and aneurysm size, and women experience rapid aneurysm growth at sizes greater than 4.5 cm. Current screening guidelines are inadequate, and our results demonstrate that the rate of growth of fusiform aneurysms in women is faster than in men at a smaller size and may warrant more frequent surveillance than current Society for Vascular Surgery recommendations to prevent risk of increased morbidity.

Multimodality magnetic resonance evaluating the effect of enhanced physical exercise on the growth rate, flow haemodynamics, aneurysm wall and ventricular-aortic coupling of patients with small abdominal aortic aneurysms (AAA MOVE trial): a study protocol for an open-label randomised controlled trial

IntroductionThe best lifestyle for small abdominal aortic aneurysms (sAAA) is essential for its conservative management. Physical exercise can improve the cardiopulmonary function of the patients, but it remains unclear which...

Risk factors of unruptured intracranial aneurysms instability in the elderly.

Presently, a consistent strategy for determining the stability of unruptured intracranial aneurysms (UIAs) in elderly patients is lacking, primarily due to the unique characteristics of this demographic. Our objective was to assess the risk factors contributing to aneurysm instability (growth or rupture) within the elderly population. In this study, we compiled data from follow-up patients with UIAs spanning from November 2016 to August 2021. We specifically focused on patients aged ≥ 60years. Clinical histories were gathered, and morphological parameters of aneurysms were measured. The growth of aneurysms was determined using the computer-assisted semi-automated measurement (CASAM). Growth and rupture rates of UIAs were calculated, and both univariate and multivariate Cox regression analyses were conducted. Additionally, Kaplan-Meier survival curves were plotted. A total of 184 patients with 210 aneurysms were enrolled in the study. The follow-up period encompasses 506.6 aneurysm-years and 401.4 patient-years. Among all the aneurysms, 23 aneurysms exhibited growth, with an annual aneurysm growth rate of 11.0%, and 1 (4.5%) experienced rupture, resulting in an annual aneurysm rupture rate of 0.21%. Multivariate Cox analysis identified poorly controlled hypertension (P = 0.011) and high-risk aneurysms (including anterior cerebral artery (ACA), anterior communicating artery (AcoA), posterior communicating artery aneurysm (PcoA), posterior circulation (PC) > 4mm or distal internal carotid artery (ICAd), middle cerebral artery (MCA), and PC > 7mm) (P = 0.006) as independent risk factors for the development of unstable aneurysms. In the elderly, poorly controlled hypertension and high-risk aneurysms emerge as significant risk factors for aneurysm instability. This underscores the importance of rigorous surveillance or timely intervention in patients presenting with these risk factors.

The natural history and long-term follow-up of splenic artery aneurysms

ObjectiveAlthough splenic artery aneurysms (SAAs) are the most common visceral aneurysm, there is a paucity of literature on the behavior of these entities. The objective of this study was to review the natural history of patients with SAA. MethodsThis single-institution, retrospective analysis studied patients with SAA diagnosed by computed tomography imaging between 2015 and 2019, identified by our institutional radiology database. Imaging, demographic, and clinical data were obtained via the electronic medical record. The growth rate was calculated for patients with radiologic follow-up. ResultsThe cohort consisted of 853 patients with 890 SAAs, of whom 692 were female (81.2%). There were 37 women (5.3%) of childbearing age (15-50 years). The mean age at diagnosis was 70.9 years (range: 28-100 years). Frequently observed medical comorbidities included hypertension (70.2%), hypercholesterolemia (54.7%), and prior smoking (32.2%). Imaging indications included abdominal pain (37.3%), unrelated follow-up (28.0%), and follow-up of a previously noted visceral artery aneurysm (8.6%). The mean diameter at diagnosis was 13.3 ± 6.3 mm. Anatomic locations included the splenic hilum (36.0%), distal splenic artery (30.3%), midsplenic artery (23.9%), and proximal splenic artery (9.7%). Radiographically, the majority were saccular aneurysms (72.4%) with calcifications (88.5%). One patient (38-year-old woman) was initially diagnosed at the time of rupture of a 25 mm aneurysm; this patient underwent immediate endovascular intervention with no complications. The mean clinical follow-up among 812 patients was 4.1 ± 4.0 years, and the mean radiological follow-up among 514 patients was 3.8 ± 6.8 years. Of the latter, 122 patients (23.7%) experienced growth. Aneurysm growth rates for initial sizes <10 mm (n = 123), 10 to 19 mm (n = 353), 20 to 29 mm (n = 34), and >30 mm (n = 4) were 0.166 mm/y, 0.172 mm/y, 0.383 mm/y, and 0.246 mm/y, respectively. Of the entire cohort, 27 patients (3.2%) eventually underwent intervention (81.5% endovascular), with the most common indications including size/growth criteria (70.4%) and symptom development (18.5%). On multivariate analysis, only prior tobacco use was significantly associated with aneurysm growth (P = .028). ConclusionsThe majority of SAAs in this cohort remained stable in size, with few patients requiring intervention over a mean follow-up of 4 years. Current guidelines recommending treatment of asymptomatic aneurysms >30 mm appear appropriate given their slow progression. Despite societal recommendations for intervention for all SAAs among women of childbearing age, only a minority underwent vascular surgical consultation and intervention in this series, indicating that these recommendations are likely not well known in the general medical community.