Baseline Aneurysm Diameter Research Articles

Aneurysm Sac Dynamics and its Prognostic Significance Following Fenestrated and Branched Endovascular Aortic Aneurysm Repair

This study aimed to assess aneurysm sac dynamics and its prognostic significance following fenestrated and branched endovascular aneurysm repair (F/BEVAR). Patients undergoing F/BEVAR for degenerative complex aortic aneurysm from 2008 to 2020 at two large vascular centres with two imaging examinations (30 day and one year) were included. Patients were categorised as regression and non-regression, determined by the proportional volume change (> 5%) at one year compared with 30 days. All cause mortality and freedom from graft related events were assessed using Kaplan-Meier methods. Factors associated with non-regression at one year and aneurysm sac volume over time were examined for FEVAR and BEVAR independently using multivariable logistic regression and linear mixed effects modelling. One hundred and sixty-five patients were included: 122 FEVAR, of whom 34% did not regress at one year imaging (20% stable, 14% expansion); and 43 BEVAR, of whom 53% failed to regress (26% stable, 28% expansion). Following F/BEVAR, after risk adjusted analysis, non-regression was associated with higher risk of all cause mortality within five years (hazard ratio [HR] 2.56, 95% confidence interval [CI] 1.09 - 5.37; p= .032) and higher risk of graft related events within five years (HR 2.44, 95% CI 1.10 - 5.26; p= .029). Following multivariable logistic regression, previous aortic repair (odds ratio [OR] 2.56, 95% CI 1.11 - 5.96; p= .029) and larger baseline aneurysm diameter (OR/mm 1.04, 95% CI 1.00 - 1.09; p= .037) were associated with non-regression at one year, whereas smoking history was inversely associated with non-regression (OR 0.21, 95% CI 0.04 - 0.96; p= .045). Overall following FEVAR, aneurysm sac volume decreased significantly up to two years (baseline vs. two year, 267 [95% CI 250 - 285] cm3vs. 223 [95% CI 197 - 248] cm3), remaining unchanged thereafter. Overall following BEVAR, aneurysm sac volume remained stable over time. Like infrarenal EVAR, non-regression at one year imaging is associated with higher five year all cause mortality and graft related events risks after F/BEVAR. Following FEVAR for juxtarenal aortic aneurysm, aneurysm sacs generally displayed regression (66% at one year), whereas after BEVAR for thoraco-abdominal aortic aneurysm, aneurysm sacs displayed a concerning proportion of growth at one year (28%), potentially suggesting a persistent risk of rupture and consequently requiring intensified surveillance following BEVAR. Future studies will have to elucidate how to improve sac regression following complex EVAR, and whether the high expansion risk after BEVAR is due to advanced disease extent.

Reintervention does not affect long-term survival after fenestrated endovascular aneurysm repair.

Fenestrated endovascular aneurysm repair (FEVAR) is increasingly used in the treatment of juxtarenal aortic aneurysms and short-neck infrarenal aneurysms. Reinterventions (REIs) occur frequently, contributing to patient morbidity and resource utilization. We sought to determine whether REI affects long-term survival after FEVAR. A single-institution retrospective review of all Cook Zenith fenestrated (ZFEN; Cook Medical, Inc, Bloomington, IN) repairs was performed. Patients with ≥6months of follow-up and without adjunctive branch modifications were included. REI was defined as any aneurysm, device, target branch, or access-related intervention after the index procedure. REIs were categorized as early (<30days) or late (≥30days), by indication (ie, branch, endoleak, limb related, access related, other), and by target branch or device components. Patients were stratified into REI vs no REI groups and branch REI vs non-branch REI groups. Of 219 consecutive ZFEN repairs from 2012 to 2021, 158 patients met the inclusion criteria. Of these 158 patients, 41 (26%) required a total of 51 REIs (10 early and 41 late) during a mean follow-up of 33.9months. The most common indication for REI was branch-related (31 of 51; 61%), with the renal arteries the most frequently affected (26 of 51; 51%). The only differences found in baseline, aneurysm, and device characteristics were a higher mean Society for Vascular Surgery comorbidity score (9.6 vs 7.9; P= .04) and larger suprarenal neck angle (23.3° vs 17.1°; P= .04) in the no REI group. In contrast, the REI group had a larger mean proximal seal zone diameter (26.3mm vs 25.1mm; P= .03) and device diameter (31.9mm vs 30.0mm; P= .002) compared with the no REI group. Technical success and operative characteristics were similar between the groups, except for a longer mean fluoroscopy time (74.9minutes vs 60.8minutes; P= .01) and longer median length of stay (2 vs 2days; P= .006) for the REI group. Although the rate of early (<30days) major adverse events was greater for the REI group (24.4% vs 6.0%; P= .001), the difference in 30-day mortality was not statistically significant (4.9% vs 0.9%; P= .10). On Kaplan-Meier analysis, freedom from REI at 1 and 5years was 85.7% and 62.6%, respectively, for the overall cohort. No difference was found in the estimated 5-year survival between the REI and no REI groups (62.8% vs 63.5%; log-rank, P= .87) and branch REI and non-branch REI groups (71.8% vs 49.9%; log-rank, P= .16). On multivariate analysis, REI was not an independent predictor for mortality. However, age, Society for Vascular Surgery comorbidity score, and preoperative maximum aneurysm diameter each increased the hazard of death (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.02-1.12 [P= .007]; HR, 1.10; 95% CI, 1.01-1.18 [P= .02]; HR, 1.05; 95% CI, 1.02-1.08 [P= .003], respectively). After ZFEN, 41 patients (26%) had required a total of 51 REIs, with most occurring ≥30days after the index procedure, and 61% were branch related, with no influence on 5-year survival. Age, comorbidity, and baseline aneurysm diameter independently predicted mortality. The use of FEVAR mandates lifelong surveillance and protocols to maintain branch patency. Despite their relative frequency, REIs did not influence 5-year postprocedural survival.

Ascending thoracic aortic aneurysm growth is minimal at sizes that do not meet criteria for surgical repair.

Historic studies of nonsyndromic ascending thoracic aortic aneurysms (aTAAs) reported that the typical aTAA growth rate was approximately 0.6 mm/year, but data were limited due to relatively few studies using computed tomography (CT) imaging. Our purpose was to reevaluate the annual growth rate of nonsyndromic aTAAs that do not meet criteria for surgical repair in veterans in the contemporary era, using modern CT imaging suitable for highly accurate and reproducible aneurysm measurement. Nonsurgical patients (diameter <5.5 cm) undergoing aneurysm surveillance at a Veterans Affairs Medical Center with repeat CT imaging performed 3 to 5 years apart were identified. Maximum diameter was determined by a single radiologist using multiplanar reformat-based measurements. Average rate of aneurysm growth was evaluated based on longest available follow-up. Sixty-seven patients were included. Average follow-up time was 4.06±0.83 years. Patients were exclusively male, with average age of 68.1±6.0 years, and the majority had a history of smoking (n=52, 78%), hypertension (n=52, 78%), and dyslipidemia (n=48, 72%). Average baseline aneurysm diameter was 44.0±3.2 mm and average growth rate was 0.11±0.31 mm/year, with no difference in growth rate between patients with initial diameter ≤45 vs. >45 mm. Only 3 patients experienced clinically significant changes in diameter with magnitude greater than 5% of baseline. In this veteran population, most patients did not experience significant annual aneurysm growth over up to 5 years of follow-up, regardless of initial diameter. Thus, in the modern era, aTAAs may not grow as quickly as previously described, which will be important in determining appropriate intervals for aneurysm surveillance based upon risk-benefit ratio.

Growth of common iliac artery aneurysms coexisting with abdominal aortic aneurysms: associated factors and potential role of intraluminal thrombus.

The factors influencing common iliac artery aneurysm (CIA) growth are not fully known. Intraluminal thrombus (ILT) has been studied as a marker of growth in abdominal aortic aneurysms (AAA), but its role in CIAs is unknown. This study aims to examine the factors associated with growth of CIAs coexistent with AAA using serial cross-sectional imaging (CT and MRI) with multiplanar reconstruction (MPR). Patients with synchronous AAA and CIA observed at contrast-enhanced CT or MRI were included. The maximal diameters of both CIA and AAA were measured using MPR. Correlation of the baseline aneurysm diameter and growth rate between CIA and AAA was evaluated. Multivariate regression analysis was used to investigate the factors associated with CIA growth. Seventy-five AAA patients (age 74±9 years; all male) with 100 CIAs were followed for an average of 2.2±1.2 years. CIA and AAA growth were positively correlated (r=0.39, P<0.001). Multivariate analysis showed that CIA baseline diameter, AAA baseline diameter, and smoking were positively related to CIA growth. In 2-3 cm CIAs (n=59), ILT tends to be an independent predictor of AAA growth (P=0.076), and CIAs with ILT grow at more than twice the rate of CIAs without ILT (1.7 vs. 0.8 mm/year, P=0.036), despite similar baseline diameters. CIA baseline diameter, coexisting AAA baseline diameter, and smoking are associated with CIA growth. In CIAs measuring 2-3 cm, the presence of ILT is associated with faster growth, and should be taken into account when determining surveillance intervals and timing of intervention for patients being considered for AAA repair.

Suprarenal fixation is associated with worse midterm renal function after endovascular abdominal aortic aneurysm repair compared with infrarenal fixation

BackgroundSeveral reports have indicated that suprarenal (SR) fixation may impair renal function after endovascular abdominal aortic aneurysm repair (EVAR). However, most were short-term or at most, 1-year observational studies; therefore, the midterm effects on renal function remain unclear. This study aimed to identify predictors of midterm renal dysfunction after EVAR and compare renal outcomes in patients after EVAR with SR and infrarenal (IR) fixation. MethodsA total of 467 patients who underwent EVAR of nonruptured IR abdominal aortic aneurysm between 2007 and 2014 were reviewed in a prospectively collected database. Patients on hemodialysis at baseline were excluded. Among the remaining patients, those with 3-year laboratory testing were included in this study. Patients who developed acute kidney injury were excluded from the late renal function estimation. Predictors of 3-year renal function decline were estimated using logistic regression analysis. In addition, patients undergoing EVAR with IR (IR group) and SR fixation devices (SR group) were propensity matched by age, sex, baseline renal function, baseline aneurysm diameter, comorbidities, smoking habits, and regular use of medicines that may act on kidney function. Changes in renal function after surgery were compared between the IR group and the SR group. ResultsDuring the study period, 237 patients (102 IRs and 135 SRs) were followed up with laboratory testing 3 years after surgery. Logistic regression analysis revealed that the use of a SR fixation device was independently predictive of a more than 20% decrease in the estimated glomerular filtration rate at 3 years after EVAR (odds ratio, 2.06; 95% confidence interval, 1.18-3.58; P = .011). Eleven patients who developed acute kidney injury (1 IR and 10 SRs) were excluded from the subsequent analysis. After propensity score matching, 87 pairs were selected (mean age, 77.2 ± 6.3 years; 151 males [86.8%]). The mean follow-up duration was 5.5 ± 1.8 years. In the SR group, estimated glomerular filtration rate at 3 years after surgery decreased significantly more than that in the IR group (mean of 17.8% vs 11.6%, respectively; P = .034). ConclusionsThis study suggests that, compared with EVAR with IR endograft fixation, EVAR with SR endograft fixation is associated with worse outcomes for midterm renal function.

Magnetic resonance imaging using ultrasmall superparamagnetic particles of iron oxide for abdominal aortic aneurysm: a risk prediction study

Background Abdominal aortic aneurysm (AAA) rupture is a common cause of sudden death. Pre-emptive elective surgical repair can prevent aneurysm rupture and be life-saving. Ultrasmall superparamagnetic particles of iron oxide (USPIO) detect cellular inflammation using magnetic resonance imaging (MRI) in patients with AAAs. For this reason, USPIO-enhanced MRI represents a promising new technique that could improve risk prediction and better guide surgical intervention. Objectives To assess whether or not USPIO-enhanced MRI can predict aneurysm growth rates and clinical outcomes in patients with AAAs. Design A prospective multicentre open-label observational cohort study. Setting Three secondary and tertiary care hospitals in Scotland. Participants Patients (n = 342) aged &gt; 40 years with a maximum anteroposterior AAA diameter of ≥ 40 mm confirmed by abdominal ultrasonography, and under ultrasonographic surveillance as part of routine clinical care. Interventions USPIO-enhanced MRI of AAA. Main outcome measures The primary end point was the composite of aneurysm rupture or repair. Secondary outcomes included rate of aneurysm growth, all-cause mortality and aneurysm-related mortality. Results Participants (85% male, aged 73.1 ± 7.2 years) had a baseline aneurysm diameter of 49.6 ± 7.7 mm, and USPIO enhancement was identified in 146 participants (42.7%), absent in 191 participants (55.8%) and indeterminate in 5 participants (1.5%). During follow-up (1005 ± 280 days), there were 17 AAA ruptures (5.0%), 126 AAA repairs (36.8%) and 48 deaths (14.0%). Compared with those without uptake, patients with USPIO enhancement have increased rates of aneurysm expansion (3.1 ± 2.5 vs. 2.5 ± 2.4 mm/year; p = 0.0424), although this was not independent of current smoking habits (p = 0.1993). The primary end point (aneurysm rupture or repair) occurred more frequently in participants with USPIO enhancement [69/146 (47.3%) vs. 68/191 (35.6%), difference 11.7%, 95% confidence interval 1.1% to 22.2%; p = 0.0308]: this was similar for each component of rupture (6.8% vs. 3.7%; p = 0.1857) or repair (41.8% vs. 32.5%; p = 0.0782). USPIO enhancement was associated with reduced event-free survival for aneurysm rupture or repair (p = 0.0275). Baseline AAA diameter (p &lt; 0.0001) and current smoking habits (p = 0.0446) also predicted the primary outcome, and the addition of USPIO enhancement to the multivariate model did not improve event prediction (c-statistic 0.7935 to 0.7936). Conclusions USPIO-enhanced MRI is a novel approach to the identification of aortic wall cellular inflammation in patients with AAAs, and predicts the rate of aneurysm growth and clinical outcome. USPIO-enhanced MRI does not provide independent prediction of aneurysm expansion or clinical outcomes in a model incorporating known clinical risk factors. Larger trials are now needed to explore the prediction of emergent aneurysm events to establish the added benefit of USPIO-enhanced MRI. Comparative outcome studies should determine whether or not using other imaging biomarkers that track alternative disease processes have better predictive capability than USPIO-enhanced MRI. Trial registration Current Controlled Trials ISRCTN76413758. Funding This project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research partnership.

18F–Sodium Fluoride Uptake in Abdominal Aortic Aneurysms: The SoFIA3 Study

BackgroundFluorine-18–sodium fluoride (18F-NaF) uptake is a marker of active vascular calcification associated with high-risk atherosclerotic plaque. ObjectivesIn patients with abdominal aortic aneurysm (AAA), the authors assessed whether 18F-NaF positron emission tomography (PET) and computed tomography (CT) predicts AAA growth and clinical outcomes. MethodsIn prospective case-control (n = 20 per group) and longitudinal cohort (n = 72) studies, patients with AAA (aortic diameter >40 mm) and control subjects (aortic diameter <30 mm) underwent abdominal ultrasound, 18F-NaF PET-CT, CT angiography, and calcium scoring. Clinical endpoints were aneurysm expansion and the composite of AAA repair or rupture. ResultsFluorine-18-NaF uptake was increased in AAA compared with nonaneurysmal regions within the same aorta (p = 0.004) and aortas of control subjects (p = 0.023). Histology and micro-PET-CT demonstrated that 18F-NaF uptake localized to areas of aneurysm disease and active calcification. In 72 patients within the longitudinal cohort study (mean age 73 ± 7 years, 85% men, baseline aneurysm diameter 48.8 ± 7.7 mm), there were 19 aneurysm repairs (26.4%) and 3 ruptures (4.2%) after 510 ± 196 days. Aneurysms in the highest tertile of 18F-NaF uptake expanded 2.5× more rapidly than those in the lowest tertile (3.10 [interquartile range (IQR): 2.34 to 5.92 mm/year] vs. 1.24 [IQR: 0.52 to 2.92 mm/year]; p = 0.008) and were nearly 3× as likely to experience AAA repair or rupture (15.3% vs. 5.6%; log-rank p = 0.043). ConclusionsFluorine-18-NaF PET-CT is a novel and promising approach to the identification of disease activity in patients with AAA and is an additive predictor of aneurysm growth and future clinical events. (Sodium Fluoride Imaging of Abdominal Aortic Aneurysms [SoFIA3]; NCT02229006; Magnetic Resonance Imaging [MRI] for Abdominal Aortic Aneurysms to Predict Rupture or Surgery: The MA3RS Trial; ISRCTN76413758)

Aneurysm sac expansion is independently associated with late mortality in patients treated with endovascular aneurysm repair

BackgroundPatients undergoing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms can exhibit variations in sac behavior ranging from complete regression to expansion. We evaluated the impact of sac behavior at 1-year follow-up on late survival. MethodsWe used the Vascular Study Group of New England (VSGNE) registry from 2003 to 2011 to identify EVAR patients with 1-year computed tomography follow-up. Aneurysm sac enlargement ≥5 mm (sac expansion) and decrease ≥5 mm (sac regression) were defined per Society for Vascular Surgery guidelines. Predictors of change in sac diameter and impact of sac behavior on long-term mortality were assessed by multivariable methods. ResultsOf 2437 patients who underwent EVAR, 1802 (74%) had complete 1-year follow-up data and were included in the study. At 1 year, 162 (9%) experienced sac expansion, 709 (39%) had a stable sac, and 931 (52%) experienced sac regression. Sac expansion was associated with preoperative renal insufficiency (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.5-8.0; P < .01), urgent repair (OR, 2.7; 95% CI, 1.4-5.1; P < .01), hypogastric coverage (OR, 1.7; 95% CI, 1.1-2.7; P = .02), and type I/III (OR, 16.8; 95% CI, 7.3-39.0; P < .001) or type II (OR, 2.9; 95% CI, 2.0-4.3; P < .001) endoleak at follow-up, and sac expansion was inversely associated with smoking (OR, 0.6; 95% CI, 0.4-0.96; P = .03) and baseline aneurysm diameter (OR, 0.7; 95% CI, 0.6-0.9; P < .001). Sac regression (vs expansion or stable sac) was associated with female gender (OR, 1.8; 95% CI, 1.4-2.4; P < .001) and larger baseline aneurysm diameter (OR, 1.4; 95% CI, 1.2-1.5; P < .001) and inversely associated with type I/III (OR, 0.2; 95% CI, 0.1-0.5; P < .01) or type II endoleak at follow-up (OR, 0.2; 95% CI, 0.2-0.3; P < .001). After risk-adjusted Cox regression, sac expansion was independently associated with late mortality (hazard ratio, 1.5; 95% CI, 1.1-2.0; P = .01), even with adjustment for reinterventions and endoleak during follow-up. Sac regression was associated with lower late mortality (hazard ratio, 0.6; 95% CI, 0.5-0.7; P < .001). Long-term survival was lower (log-rank, P < .001) in patients with sac expansion (98% 1-year and 68% 5-year survival) compared with all others (99% 1-year and 83% 5-year survival). ConclusionsThese data suggest that an abdominal aortic aneurysm sac diameter increase of at least 5 mm at 1 year, although infrequent, is independently associated with late mortality regardless of the presence or absence of endoleak and warrants close observation and perhaps early intervention.

Aortic Wall Inflammation Predicts Abdominal Aortic Aneurysm Expansion, Rupture, and Need for Surgical Repair.

Ultrasmall superparamagnetic particles of iron oxide (USPIO) detect cellular inflammation on magnetic resonance imaging (MRI). In patients with abdominal aortic aneurysm, we assessed whether USPIO-enhanced MRI can predict aneurysm growth rates and clinical outcomes. In a prospective multicenter open-label cohort study, 342 patients with abdominal aortic aneurysm (diameter ≥40 mm) were classified by the presence of USPIO enhancement and were monitored with serial ultrasound and clinical follow-up for ≥2 years. The primary end point was the composite of aneurysm rupture or repair. Participants (85% male, 73.1±7.2 years) had a baseline aneurysm diameter of 49.6±7.7 mm, and USPIO enhancement was identified in 146 (42.7%) participants, absent in 191 (55.8%), and indeterminant in 5 (1.5%). During follow-up (1005±280 days), 17 (5.0%) abdominal aortic aneurysm ruptures, 126 (36.8%) abdominal aortic aneurysm repairs, and 48 (14.0%) deaths occurred. Compared with those without uptake, patients with USPIO enhancement have increased rates of aneurysm expansion (3.1±2.5 versus 2.5±2.4 mm/year, P=0.0424), although this was not independent of current smoking habit (P=0.1993). Patients with USPIO enhancement had higher rates of aneurysm rupture or repair (47.3% versus 35.6%; 95% confidence intervals, 1.1-22.2; P=0.0308). This finding was similar for each component of rupture (6.8% versus 3.7%, P=0.1857) or repair (41.8% versus 32.5%, P=0.0782). USPIO enhancement was associated with reduced event-free survival for aneurysm rupture or repair (P=0.0275), all-cause mortality (P=0.0635), and aneurysm-related mortality (P=0.0590). Baseline abdominal aortic aneurysm diameter (P<0.0001) and current smoking habit (P=0.0446) also predicted the primary outcome, and the addition of USPIO enhancement to the multivariate model did not improve event prediction (c-statistic, 0.7935-0.7936). USPIO-enhanced MRI is a novel approach to the identification of aortic wall cellular inflammation in patients with abdominal aortic aneurysms and predicts the rate of aneurysm growth and clinical outcome. However, it does not provide independent prediction of aneurysm expansion or clinical outcomes in a model incorporating known clinical risk factors. URL: http://www.isrctn.com. Unique identifier: ISRCTN76413758.

Standard endovascular aneurysm repair in patients with wide infrarenal aneurysm necks is associated with increased risk of adverse events

ObjectiveEndovascular aneurysm repair (EVAR) has progressively expanded to treat more challenging anatomies. Although EVAR in patients with wide infrarenal necks has been reported with acceptable results, there is still controversy regarding the longer-term outcomes. Our aim is to determine the impact of infrarenal neck diameter on midterm outcome following EVAR with a single endograft with suprarenal fixation. MethodsA retrospective case-control study was designed using data from a prospective multicenter database. Patients who electively underwent standard EVAR with an Endurant stent graft (Medtronic Ave, Santa Rosa, Calif) for a degenerative abdominal aortic aneurysm from January 2008 to December 2012 in three high-volume centers in The Netherlands were included. All measurements were obtained using dedicated reconstruction software and center-lumen line reconstruction. Patients with an infrarenal neck diameter of ≥30 mm were compared with patients with a neck diameter of <30 mm. The primary end point was freedom from neck-related adverse events (a composite of type Ia endoleak, neck-related secondary intervention, and endograft migration). Secondary end points were primary clinical success, type Ia endoleak, neck-related reinterventions, endoleaks, and aneurysm-related secondary interventions. ResultsFour-hundred twenty-seven patients were included. Seventy-four patients (17.3%) with a neck diameter of ≥30 mm were compared with a control group of 353 patients. There were no significant differences at baseline between groups including demographics, comorbidities, baseline aneurysm diameter, infrarenal neck length, suprarenal angulation, or infrarenal neck angulation. Median stent graft oversizing was 12.5% (7.9-16.1) and 16.6% (12.0-23.1) in the ≥30-mm neck-diameter and control groups, respectively (P < .001). Median follow-up was 3.1 years (1.2-4.7) and 4.1 years (2.7-5.6) for the large neck and control groups, respectively (P < .001). Type Ia endoleaks occurred in 17 patients (4.0%) and were significantly more frequent in patients with ≥30-mm neck diameter (9.5% vs 2.8%; P = .005). Neck-related secondary interventions were performed in 20 patients (4.7%) and were also more common among patients with neck diameters of ≥30 mm (9.5% vs 3.7%; P = .04). The 4-year freedom from neck-related adverse events were 75% and 95% for the large neck and control groups, respectively (P < .001). On multivariable regression analysis, infrarenal neck diameter of ≥30 mm was an independent risk factor for neck-related adverse events (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.6-9.1), type Ia endoleak (OR, 2.7; 95% CI, 1.0-8.3), and neck-related secondary interventions (OR, 3.2, 95% CI, 1.1-9.2). ConclusionsEVAR in patients with large diameter necks is associated with an increased risk of neck-related adverse events in midterm follow-up. This may influence the clinical decision regarding choice of repair and toward a more intensive surveillance following EVAR in these patients in the long term.

RS13. Standard Endovascular Aneurysm Repair in Patients With Wide Proximal Aneurysm Necks Is Associated With Increased Risk of Adverse Events

Endovascular aneurysm repair (EVAR) has progressively expanded to treat progressively more challenging anatomies. Although EVAR in patients with large proximal necks has been reported with acceptable results, there is still controversy regarding the midterm outcomes. Our aim is to determine the impact of proximal neck diameter on midterm outcome after EVAR with a single endograft with suprarenal fixation. A retrospective case-control study was designed using data from a prospective multicenter database. All measurements were obtained using dedicated reconstruction software and center-lumen line reconstruction. Patients who electively underwent standard EVAR with an Endurant stent graft (Medtronic AVE, Santa Rosa, Calif) for a degenerative AAA from January 2008 to December 2012 in three high-volume centers in the Netherlands were included. Patients with a proximal neck diameter ≥30 mm were compared to the remaining population. Primary end point was freedom from neck-related adverse events (type IA endoleak, neck-related secondary intervention, endograft migration >10 mm). Secondary end points were freedom from rupture, type 1A endoleak and neck-related reinterventions. A total of 427 patients were included; of these, 74 patients (17.3%) with a neck diameter ≥30 mm were compared to a control group of 353 patients. Median follow-up was 3.1 years (1.2-4.7) and 4.1 years (2.7-5.6) for the large-neck and control groups, respectively (P < .001). The two groups did not differ regarding demographics, comorbidities, baseline aneurysm diameter (P = .39), proximal neck length (P = .72), suprarenal angulation (P = .76), or infrarenal angulation (P = .99). Mean stent graft oversizing was 13.2% ± 5.2% and 17.8% ± 8.0% in the large-neck and control groups, respectively (P < .001). The 4-year freedom from neck-related adverse-events estimates were 75% and 95% for the large-neck and control groups, respectively (P < .001; Fig). Proximal neck diameter ≥30 mm was associated with a fourfold increased risk of neck- related adverse events in a multivariable model (HR, 4.3; 95% CI, 1.9-9.7; P < .001). Type IA endoleaks occurred in 16 patients (3.7%) and were significantly more frequent in patients with large neck diameters (7 [9.5%]; P = .005). Neck-related secondary interventions were performed in 20 patients (4.7%) and were also more common among patients with neck diameters ≥30 mm (7 [9.5%]; P = .035). Secondary aneurysm rupture occurred in 7 patients but was not associated to large proximal aneurysm neck (P = .82). EVAR in patients with large-diameter necks is associated with an increased risk of neck-related adverse events in midterm follow-up. This may influence the clinical decision regarding choice of repair and towards a more intensive surveillance after EVAR.

The Effect of Chemotherapy for Malignancy on the Natural History of Aortic Aneurysm

Surgical dogma holds that chemotherapy increases the risk of aneurysm growth and rupture. We sought to determine the effect of cytotoxic chemotherapy on the growth of aortic aneurysms. All patients undergoing chemotherapy for malignancy with coexisting aortic aneurysms at our institution between 2000 and 2011 were identified. A review of electronic medical records and a re-review of serial cross-sectional imaging was performed. An additional cohort of patients undergoing aneurysm surveillance during the same period was identified, and demographic and anatomic variables were collected. Planned analysis included descriptive analysis, change in aneurysm diameter over time, and association of growth or need for intervention with type of chemotherapy and type of malignancy. Between 2000 and 2010, there were 125 patients at our institution with a concurrent diagnosis of aortic aneurysm and malignancy requiring cytotoxic chemotherapy. Cross-sectional imaging was available for 91 of the 125 patients. The predominant malignancy type was lung cancer in 34 of 91 patients (38%), followed by lymphoma in 21 (23%) and colorectal cancer in 10 (11%). The aneurysms in 53 patients (58%) were infrarenal. Most patients were treated with more than one class of chemotherapeutic agent over 267 days (interquartile range [IQR], 144-469 days), the majority having at least one cycle of alkylating agents (73 of 91), in addition to antimetabolites (42 of 91) and plant alkyloids/terpenoids (40 of 91). Chemotherapy regimens included steroids in 84 patients (92%). The baseline aneurysm diameter for patients on and not on chemotherapeutic agents was 41.4 mm (IQR, 34.9-51.3 mm) and 46.0 mm (IQR, 40-52 mm), respectively. Aneurysm repair during chemotherapy occurred in eight of 91 patients (9%), but only two required urgent repair due to aneurysm rupture. The annual rate of aneurysm growth for patients on and not on chemotherapy was similar (2.3 mm/y vs 2.4 mm/y; P = .69). In 91 patients over 10 years at our institution, chemotherapy did not increase aneurysm growth compared with patients not undergoing treatment for malignancy.

Impact of gender and body surface area on outcome after abdominal aortic aneurysm repair

BackgroundA gender-neutral threshold aneurysm diameter (AD) of more than 5.5 cm for surgical intervention in abdominal aortic aneurysms (AAA) ignores the fact that women have a smaller baseline AD. We hypothesized that women have a greater AD relative to body surface area (BSA) at the time of surgery and that this worsens outcome. MethodsThe Vascular Study Group of New England database was queried for elective AAA repairs performed from 2003 to 2011 to compare BSA-indexed AD, ie, aortic size index (ASI), between men and women at the time of surgery and the impact of ASI on outcome. ResultsWomen were older and had higher ASI among both open-repair (n = 1,566) and endovascular repair (n = 2,172) patients (P < .001). Among open-repair patients, mean ASI for men undergoing repair at AD of 5.5 cm (2.75 cm/m²) was used to subdivide women into 2 categories: women with ASI of 2.75 or more were older (P < .001), had a larger aneurysm size (P < .001), and had a higher 1-year mortality (P = .042) than women with ASI less than 2.75. ConclusionsWhen indexed to BSA, women have a larger aneurysm size than men at the time of AAA repair.

The effect of chemotherapy for malignancy on the natural history of aortic aneurysm

Surgical dogma holds that chemotherapy increases the risk of aneurysm growth and rupture. We sought to determine the effect of cytotoxic chemotherapy on the growth of aortic aneurysms. All patients undergoing chemotherapy for malignancy with coexisting aortic aneurysms at our institution between 2000 and 2011 were identified. Review of electronic medical records and rereview of serial cross-sectional imaging was performed. An additional cohort of patients undergoing aneurysm surveillance during the same period was identified, and demographic and anatomic variables were collected. Planned analysis included descriptive analysis, change in aneurysm diameter over time, and association of growth or need for intervention with type of chemotherapy and type of malignancy. Between 2000 and 2011, 125 patients at our institution had a concurrent diagnosis of aortic aneurysm and malignancy requiring cytotoxic chemotherapy. Cross-sectional imaging was available for 91 patients. The predominant malignancy type was lung cancer (34 of 91 [38%]), followed by lymphoma (21 of 91 [23%]) and colorectal cancer (10 of 91 [11%]). Most aneurysms were infrarenal (53 of 91 [58%]). Most patients were treated with more than one class of chemotherapeutic agent over 267 days (interquartile range [IQR], 144-469 days), and most had at least one cycle of alkylating agents (73 of 91), in addition to antimetabolites (42 of 91) and plant alkaloids/terpenoids (40 of 92). Chemotherapy regimens included steroids in 84 patients (92%). The baseline aneurysm diameter was 41.4 mm (IQR, 34.9-51.3 mm) for patients who received chemotherapeutic agents and 46.0 mm (IQR, 40-52 mm) for those who did not. Eight of the 91 patients (9%) underwent aneurysm repair during chemotherapy, but only two required urgent repair due to aneurysm rupture. The rate of aneurysm growth per year for patients who did and did not receive chemotherapy was similar at 2.3 mm vs 2.4 mm (P = .69). In 91 patients over 10 years at our institution, chemotherapy did not increase aneurysm growth compared with patients not undergoing treatment for malignancy.

Effects of diabetes on small aortic aneurysms under surveillance according to a subgroup analysis from a randomized trial

This study aims to investigate the impact of diabetes in the management of patients with small abdominal aortic aneurysms (AAA). Three-hundred sixty patients with small AAA (4.1-5.4 cm), enrolled in a randomized trial comparing early endovascular repair versus surveillance and delayed repair (after achievement of >5.5 cm or growth>1 cm/yr), were analyzed with standard survival methods to assess the relation between diabetes and risk of all-cause mortality, complications, and aneurysm growth (on computed tomography as per trial protocol) at 36 months. Baseline covariates were selected with partial likelihood stepwise method to investigate factors (demographic, morphologic, medications) associated with risk of aneurysm growth during surveillance. Prevalence of diabetes was 13.6%. The hazard ratio (HR) for all-cause mortality at 36 months was higher in diabetic compared with nondiabetic patients: (HR, 7.39; 95% confidence interval [CI], 1.55-35.13; P=.012). Baseline aneurysm diameter was comparable between diabetic and nondiabetic patients enrolled in the surveillance arm and was related to subsequent aneurysm growth in covariance analyses adjusted for diabetes (49.3 mm for nondiabetic; 50.2 mm for diabetic). Cox analyses found diabetes as the strongest independent negative predictor of 63% lower probability of aneurysm growth>5 mm during surveillance (HR, 0.37; 95% CI, 0.15-0.92; P=.003). Kaplan-Meier cumulative probability of aneurysm growth>5 mm at 36 months was 40.8% in diabetics versus 85.1% in nondiabetics (HR, 0.32; 95% CI, 0.17-0.61). Progression of small AAA seems to be more than 60% lower in patients with diabetes. This may help to identify high-risk subgroups at higher likelihood of AAA enlargement, such as nondiabetics, for surveillance protocols in patients with small AAA.

EVAR May Reduce the Risk of Aneurysm Rupture Despite Persisting Type Ia Endoleaks

To determine the risk of aneurysm rupture in patients with persisting proximal type Ia endoleaks following endovascular aneurysm repair (EVAR) in comparison to the risk of rupture of untreated abdominal aortic aneurysms (AAA) of similar size. Among 400 patients who where treated with EVAR from 1996 to 2003 at a single center, 21 (5.3%) patients (13 men; mean age 78.0±5.0 years, range 67-86) with large (≥5.5 cm) aneurysms had imaging evidence of type Ia endoleaks that persisted >10 months (type Ia group) despite secondary endovascular treatment. These patients were compared to 24 untreated AAA patients (17 men; mean age 73.8±5.2 years, range 64-88) with large aneurysms from a separate geographic region with a well-established aneurysm treatment program before EVAR became available (1990-1998). There were no significant differences between the type Ia and the untreated AAA patients with regard to age (79±8 vs. 74±5 years), gender (38% vs. 29% women), baseline aneurysm diameter (6.1±0.7 vs. 6.4±0.9 cm), or length of follow-up (32±23 vs. 29±40 months). During the follow-up period, the rate of aneurysm enlargement was significantly lower in type Ia patients (0.19 cm/y) than in untreated AAA patients (0.54 cm/y, p = 0.03). One (4.8%) patient with a persisting type Ia endoleak and 2-cm aneurysm enlargement (0.8 cm/y) had aneurysm rupture after 2.5 years, while 12 (50%) of the 24 untreated aneurysms ruptured (p = 0.001), which was the primary cause of death in this group. The rupture rate was 1.8 per 100 patient-years in the type Ia group and 20.7 per 100 patient-years in the untreated AAA group. Aneurysm-related mortality was significantly reduced in the type Ia group compared to the untreated AAA group at 36 months (11% vs. 52%, p = 0.004). In the multivariate analysis, factors associated with death were an untreated AAA (odds ratio 97, p = 0.004), female gender (odds ratio 9.7, p = 0.02), and baseline aneurysm size (odds ratio 4.7/cm, p = 0.03). This study suggests that EVAR may reduce the risk of rupture and aneurysm-related death despite the presence of a persisting type Ia endoleak. This finding is limited to patients with aortic endografts that are in good position. The mechanism of protection from rupture is unclear but may be related to reducing the rate of aneurysm enlargement.

The use of statins and fate of small abdominal aortic aneurysms

The aim of this study was to evaluate the value of statins in reducing abdominal aortic aneurysm (AAA) growth rate and improving freedom from aneurysm repair or rupture. One hundred and twenty-one patients with AAA undergoing ultrasonographic surveillance for at least one year were included in this retrospective study. Patients treated with statins had a decreased linear aneurysm growth rate than those not receiving statins (1.9+/-1.8 mm/year vs. 2.6+/-2.4 mm/year, P=0.27), but this difference did not reach statistical significance. Statin users had a better survival freedom from aneurysm repair or rupture (at 5 years: 72.3% vs. 52.5%, P=0.048). The impact of treatment with statins was even more evident in patients with a baseline aneurysm diameter<40 mm (at 5 years: 84.0% vs. 58.8%, P=0.022). When adjusted for age, coronary artery disease and baseline aneurysm diameter, treatment with statins had significantly better survival freedom from aneurysm repair or rupture (P=0.012, RR 0.34, 95% CI 0.14-0.78). The use of statins seems to slightly decrease the AAA growth rate and to significantly improve freedom from aneurysm repair and rupture.