The Influence of Preoperative Aneurysmal Thrombus Quantity and Distribution on the Development of Type II Endoleaks with Aneurysm Sac Enlargement After EVAR of AAA

The impact of dyslipidemia on prognosis of patients after endovascular abdominal aortic aneurysm repair

Introduction

Dyslipidemia is common in patients with abdominal aortic aneurysm (AAA). However, there is insufficient research on the impact of dyslipidemia on the postoperative outcomes of patients with AAA after endovascular aortic aneurysm repair (EVAR). This study aimed to determine the impact of dyslipidemia on the prognosis of patients with AAA treated with EVAR.

Method

We retrospectively reviewed patients with AAA who underwent EVAR at our hospital between 2010 and 2020. The baseline characteristics and prognoses of patients in the dyslipidemia and non-dyslipidemia groups were analyzed.

Results

A total of 641 patients were included; the prevalence of dyslipidemia in patients with AAA was 42.3% (271/641), and the mean follow-up time was 63.37 ± 26.49 months. The prevalence of diabetes (10.0% vs. 15.1%, P = 0.050), peripheral arterial disease (17.3% vs. 25.8%, P = 0.018), and chronic kidney disease (3.0% vs. 6.3%, P = 0.043) was higher in the dyslipidemia group. The three-year all-cause mortality rate after EVAR was 9.98% (64/641), and there was no difference in the incidence of all-cause mortality (10.27% vs. 9.59%, P = 0.778) between the two groups. A total of 36 (5.62%) major adverse cardiovascular and cerebrovascular events (MACCEs) were observed within 3 years and were more common in patients with dyslipidemia (2.97% vs. 9.59%, P < 0.001). The incidence of stent-related complications in all patients was 19.97% (128/641), and there was no difference in the incidence of stent-related complications between the two groups (22.16% vs. 16.97%, P = 0.105); however, the incidence of type I endoleak in the dyslipidemia group was lower than that in the non-dyslipidemia group (9.19% vs. 4.06%, P = 0.012). Cox-regression analysis showed that high level of high-density lipoprotein cholesterol (HDL-C) was the protective factor (HR, 0.203, 95% CI, 0.067-0.616, P = 0.005) for MACCES, but it was the risk factor for type I endoleak (HR, 2.317, 95% CI, 1.202-4.466, P = 0.012).

Conclusion

Dyslipidemia did not affect the mortality of patients with AAA who underwent EVAR; however, it may increase the incidence of MACCEs. Dyslipidemia may decrease the incidence of type I endoleaks after EVAR; however, further studies are warranted. We should strengthen the postoperative management of patients with dyslipidemia, prevent the occurrence of MACCEs.

Patent iliolumbar artery increase no risk of type II endoleaks after endovascular abdominal aortic aneurysm: a case-control study

Objective

The aims of the present study were to explore the risk factors for type 2 endoleaks (T2ELs) after endovascular aneurysm repair (EVAR) and the association between T2ELs and the iliolumbar artery.

Materials and methods

A single-center, retrospective case-control study in West China Hospital was conducted among patients with infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between June 2010 and June 2019. The associations of patient characteristics, anatomical factors, internal iliac artery embolization, and ILA with the primary outcome were analyzed. The secondary objective was to analyze survival and reintervention between the T2EL group and the non-T2EL group. Kaplan-Meier survival, propensity matching analysis and multivariate logistic regression analysis were used.

Results

A total of 603 patients were included. The median follow-up was 51 months (range 5.0-106.0). There was a significant difference in the diameter of the lumbar artery (LA), middle sacral artery (MSA) and inferior mesentery artery (IMA), proportion of thrombus and LA numbers. The univariate analysis showed that T2ELs were more likely to develop more thrombus in aneurysm cavity (OR = 0.294, p = 0.012), larger MSA (OR = 1.284, p = 0.04), LA (OR = 1.520, p = 0.015), IMA (OR = 1.056, p < 0.001) and more LAs (OR = 1.390, p = 0.019). The multivariate analysis showed that the number of LAs (HR: 1.349, 95% CI: 1.140-1.595, p < .001) and the diameter of the IMA (HR: 1.328, 95% CI: 1.078-1.636, p = 0.008) were significantly associated with T2ELs. There were no new findings from the propensity score matching. The reintervention-free survival rates were significantly different between the two groups (p = 0.048). Overall survival and AAA-related death rates were not different between the two group. This was consistent with the PSM analysis.

Conclusion

The iliolumbar artery and the different internal iliac artery interventions may not increase the incidence of T2ELs. But the numbers of LAs and IMA diameter were independent risk factors for T2Els. T2ELs was associated with the reintervention but did not affect long-term survival or increase aneurysm-related mortality after EVAR.

Positive association between calcium channel blocker treatment and persistent type II endoleak

BACKGROUND

Type II endoleaks are the most common complication occuring after endovascular abdominal aortic aneurysm repair (EVAR). The aim of our study was to evaluate the impact of persistent type II endoleak on sac dynamics post-EVAR, and to study the association between non-anatomical factors including polymorphisms associated with abdominal aortic aneurysm (AAA) and persistent type II endoleak.

METHODS

The cohort comprises of 210 patients undergoing EVAR between January, 2010 and December, 2018. A persistent type II endoleak was defined as any type II endoleak lasting longer than six months and included also a type II endoleak diagnosed after six months or more post-EVAR during the 36-month follow-up period confirmed with CT-angiography. Anteroposterior AAA maximum diameter and AAA volume were measured pre-EVAR and 36 months post-EVAR using CT-angiographic pictures. Sac progression was defined as at least 5 mm increase, sac regression as at least 5 mm decrease in the sac diameter in relation to the preprocedural diameter. Sociodemographic information, comorbidities, treatment, laboratory parameters, selected anatomical and genetic factors were all analysed to determine their impact on persistent type II endoleak. The adjustments included age, hypertension, diabetes mellitus, dyslipidaemia, sex, smoking in multivariate analyses. When postprocedural diameter and volume were evaluated, adjustments included also preprocedural diameter/volume.

RESULTS

After exclusion, 178 pacients with mean age 72.4±7.60 years remained for analysis. Persistent type II endoleak was found in 27.5% of patients (n=49) and 2.94-times increased risk of sac progression in multivariate analysis (p=0.033). In multivariate analysis, AAA diameter in patients with persistent type II endoleak was 4.31 mm greater than in patients without (B=4.31; p=0.014); and its presence was also associated with 22.0 cm³ greater sac volume (B=22.0; p=0.034) compared to patients without persistent type II endoleak. Treatment with calcium channel blockers increased risk of persistent type II endoleak 2.11-times in multivariate analysis (OR 2.11; 95% CI 1.05-4.25; p=0.037). No association between persistent type II endoleak and selected polymorphisms associated with AAA and other observed factors was found.

CONCLUSIONS

Risk of persistent type II endoleak was more than doubled in patients taking calcium channel blockers. Patients with persistent type II endoleak had greater anteroposterior sac diameter and sac volume compared to patients without persistent type II endoleak.

Impact of abdominal aortic aneurysm sac shrinkage following endovascular repair on long-term outcomes between favorable and hostile neck anatomy

OBJECTIVE

The aim of the present study was to analyze the influence of abdominal aortic aneurysm sac shrinkage on long-term outcomes after endovascular aneurysm repair (EVAR) between patients with favorable and hostile neck anatomy.

METHODS

This study retrospectively analyzed data from 268 patients with fusiform aneurysm and sac behavior who were evaluated for ≥1 year after EVAR. Hostile neck anatomy was defined as a proximal aneurysmal neck length of <10 mm or proximal neck angle of ≥60°. The primary endpoint was sac shrinkage, and the secondary endpoints included re-intervention and a composite of rupture, type 1a endoleak, and late open conversion.

RESULTS

There was no difference in sac shrinkage between patients with favorable and hostile neck anatomy (P = .47). Multivariate analysis revealed that occluded inferior mesenteric artery (P = .04), presence of posterior thrombus (P < .01), and no antiplatelet therapy (P = .01) were positive factors for sac shrinkage. The re-intervention free survival rate was better in patients with sac shrinkage compared with those without sac shrinkage regardless of proximal neck anatomy (P < .01). The event-free survival rate of the composite endpoint at 5 and 10 years were 97.5% and 83.5% in patients with favorable neck, and 86.8% and 81.0% in those with hostile neck (P = .02). In the subgroup with sac shrinkage, the event-free survival rates at 5 and 10 years were 98.7% and 98.7% in patients with favorable neck, and 92,7% and 82.4% in those with hostile neck (P = .02). In contrast, the event-free survival of patients without sac shrinkage did not differ between those with favorable and hostile neck (P = .08). Multivariate analysis showed that hostile neck anatomy (Hazard ratio [HR], 3.32; 95% confidence interval [CI], 1.26-8.80; P = .02) and no sac shrinkage (HR, 3.88; 95% CI, 1.25-12.0; P = .02) were significant risk factors for composite of rupture, type 1a endoleak, and late open conversion.

CONCLUSIONS

Proximal neck anatomy did not affect sac shrinkage after EVAR. Sac shrinkage is a good surrogate marker of better long-term outcomes after EVAR in patients with favorable neck anatomy. In contrast, critical events such as rupture or type 1a endoleak may occur even after sac shrinkage has been achieved in patients with hostile neck anatomy.

Effects of antithrombotic therapy on abdominal aortic aneurysm sac size after endovascular repair in patients with favorable neck anatomy

PURPOSE

To evaluate the influence of antiplatelet or anticoagulant therapy on sac behavior after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) MATERIALS AND METHODS: This study retrospectively analyzed data from patients with favorable neck anatomy who underwent EVAR between 2007 and 2019. Patients with ruptured AAA and ≤1 year of sac behavior evaluation were excluded. Sac shrinkage after 1 year, persistent type II endoleak, and late sac expansion were examined.

RESULTS

In total, 182 patients with favorable neck anatomy were included in this study. Multivariable analysis identified occluded inferior mesenteric artery (IMA [P = .049]), presence of posterior thrombus (P = .009) and no antiplatelet therapy (P = .012) as factors positively associated with sac shrinkage at 1 year. Persistent type II endoleak was detected in 56 (30.8%) patients, with patent IMA (P = .006), lack of posterior thrombus (P = .004), number of patent lumbar arteries (P = .004), and antiplatelet therapy (P = .039) being identified as significant risk factors. Multivariable analysis identified larger initial AAA diameter (P < .001), lack of posterior thrombus (P = .038), and antiplatelet (P = .038) and anticoagulation therapies (P = .003) as risk factors for late sac expansion.

CONCLUSIONS

After EVAR in patients with favorable neck anatomy, antiplatelet therapy is associated with lack of sac regression at 1 year, whereas antiplatelet and anticoagulant therapies are risk factors for late sac expansion.

Changes in Neck Angle, Neck Length, Maximum Diameter, Maximum Area and Thrombus after Endovascular Aneurysm Repair

Purpose

The correlation of initial anatomy of the aneurysm, aneurysmal remodeling and endoleaks is controversial. We performed a retrospective study to measure aneurysmal remodeling with time, and to assess the structural changes in the aneurysm neck after endovascular aneurysm repair (EVAR).

Materials and Methods

From January 2013 to February 2018, 108 patients with abdominal aortic aneurysms (AAA) underwent EVAR. Follow-up computed tomography images were available for 90 patients. Anatomic variables, including the neck angle, neck length, maximal diameter, maximal area, and thrombus volume were measured. Temporal changes were measured preoperatively, immediate postoperatively (within 1 week after EVAR), and at 6 months, 1 year, and 2 years post-EVAR. Correlation between the variables according to the temporal changes and presence of type Ia endoleaks (T1aE) was analyzed.

Results

The mean follow-up period was 10.63±20.34 months. Significant decreases in neck angle and length occurred immediately postoperative (P<0.001 and 0.036). Maximum diameter decreased at 6 months post-EVAR (P=0.003), but no significant changes in the maximal area occurred over time (P=0.142). Thrombus volume in the aneurysm sac increased immediately post-EVAR (P=0.008). There was no significant relationship between T1aE and neck changes in the group and time comparison (P=0.815 and 0.970).

Conclusion

Changes in neck angle, length and thrombus volume occurred immediately after EVAR, whereas a change in the maximum diameter of the AAA was noted 6 months after EVAR. Preoperative anatomic variables related with T1aE were not found.

Aneurysm Sac Thrombus Volume Predicts Aneurysm Expansion with Type II Endoleak After Endovascular Aneurysm Repair

BACKGROUND

Several studies have analyzed risk factors that may influence the incidence of type II endoleak with sac expansion after endovascular aneurysm repair (EVAR). However, the impact of intraluminal thrombus volume on the incidence of sac expansion with type II endoleak requires further analysis. This study examined the correlation between preoperative intraluminal thrombus and the incidence of type II endoleak and late sac expansion by measuring the thrombus volume.

METHODS

Between June 2007 and March 2014, 423 patients underwent EVAR at our institution. Two hundred and eighty patients with preoperative and postoperative computed tomography angiography (CTA) were included in this study. Data were collected prospectively and supplemented with a retrospective review of the medical records and radiologic images, and demographic and clinical characteristic profiles were collected. Logistic regression and Cox regression analyses were used to assess each variable's association with the incidences of persistent or new endoleak and sac expansion.

RESULTS

Of the 280 patients, 46.7% (131 patients) had persistent type II endoleak, and 19.6% (55 patients) had persistent type II endoleak with significant sac expansion (≥5 mm). The mean follow-up duration was 60 months (interquartile range, 24-72 months). Cox regression analysis showed that older age (P = 0.001), intraluminal thrombus volume ratio (thrombus volume [T vol]/aortic aneurysm volume [A vol]) (P = 0.042) and IMA diameter (P = 0.004) were significant predictors of the incidence of sac expansion with persistent or new type II endoleak. The receiver operating characteristic curve analysis revealed a cutoff of 51% T vol/A vol (area under the curve [AUC]: 0.59) and 2.9 mm (area under the curve [AUC]: 0.60). The rate of freedom from sac expansion (≥5 mm) during followup was significantly higher in patients with ≥51% T vol/A vol than in those with a lower T vol/A vol (P = 0.010).

CONCLUSIONS

Preoperative sac thrombus volume, IMA diameter, and older age predict the incidence of aneurysm expansion with type II endoleak after EVAR.

Aortic sac enlargement after endovascular aneurysm repair: volume-related changes and the impact of intraluminal thrombus

Purpose

Abdominal aortic aneurysm (AAA) growth after endovascular aneurysm repair (EVAR) is still unpredictable. The issue of optimal frequency of computed tomography angiography for surveillance and its measurement method accuracy remain unclear. We aimed to assess the value of abdominal aneurysm sac volume measurement for detecting expansions and the association of preprocedural intraluminal thrombus (ILT) volume with aneurysm sac growth following EVAR.

Material and methods

A total of 107 patients underwent elective EVAR. Inclusion criteria provided a cohort of 39 patients. Changes of postoperative maximum aneurysm sac diameter and AAA volume were calculated. Volumetric AAA changes and demographic data of the cases with clinically irrelevant AAA diameter enlargement were evaluated. Preoperative ILT volumes were collected. ILT and AAA sac volume ratio was calculated. Statistical data analysis was performed using standard methods.

Results

The mean changes of maximum AAA diameter and volume in percentage after EVAR were –5.08 ± 8.20 mm and –13.39 ± 23.32%, respectively. A moderate positive linear correlation between those changes was found (R² = 0.731; p < 0.0001). The mean relative AAA volume increase in cases without clinically relevant diameter enlargement was 11.50 ± 8.27%. The means of ILT and AAA sac ratios were 0.59 ± 0.17 and 0.52 ± 1.8 in growing AAA sac and in stable or shrinking AAA sac groups, respectively (p = 0.308).

Conclusions

Volumetric AAA measurement may be useful as an additional method to diameter measurement after EVAR to identify clinically relevant sac growth. Preoperative volume of ILT may not significantly affect the growth rate of AAA after EVAR.

2D-shear wave elastography in the prediction of type II endoleaks after endovascular aneurysm repair

PURPOSE

To evaluate the usefulness of 2D-shear wave elastography (2D-SWE) in the prediction of type II endoleaks after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA).

MATERIAL AND METHODS

Twenty-nine patients underwent EVAR for AAA, and 2D-SWE was performed after EVAR. Follow-up contrast-enhanced CT and ultrasonography were performed to evaluate endoleaks in all patients. The median follow-up period was 12 months (range, 3-12 months). Patients were divided into two groups: one with an endoleak (endoleak group) and another without it (control group). We compared the elasticity index (EI) of intraluminal thrombus (ITL) and fresh thrombus (FT) between the two groups.

RESULTS

Type II endoleaks were confirmed in five of the 29 patients (endoleak group), and there were no endoleaks in the other 24 (control group). ILT was observed in 21 patients of the control group and in all patients of the endoleak group. There was a difference only in EI of ILT; the mean EI (± standard deviation) of ILT was 89 ± 16 kPA in the control group and 113 ± 25 kPA in the endoleak group (p=.037).

CONCLUSIONS

High EI of ILT may predict the occurrence of type II endoleaks after EVAR of AAA.

Pre-operative Aneurysm Thrombus Volume, But Not Density, Predicts Type 2 Endoleak Rate Following Endovascular Aneurysm Repair

BACKGROUND

The impact of aneurysm thrombus characteristics on type 2 endoleak rate following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is unclear. The purpose of this study is to determine the impact of pre-operative aneurysm thrombus volume and density on the incidence of type 2 endoleak following EVAR for infrarenal AAA.

METHODS

A retrospective analysis was completed on all patients who underwent standard EVAR at an academic medical institution between May 1, 2010 and June 1, 2016 with a minimum follow-up period of 12 months. The final analysis included 170 patients. Thrombus volume and density were determined by analyzing pre-operative computed tomography angiography (CTA) scans using the TeraRecon plaque analysis module. The number and diameter of patent infrarenal aortic branch vessels were also identified. Type 2 endoleak was diagnosed by post-operative CTA, duplex ultrasound, or angiography.

RESULTS

Over a median follow-up period of 29 months, 88 (51.8%) of 170 patients had a type 2 endoleak. The thrombus volume as a proportion of the infrarenal aorta volume was significantly lower in patients with type 2 endoleak (odds ratio [OR] 0.034, 95% confidence interval [CI] 0.005-0.291, P = 0.002). The number of patent lumbar arteries was significantly greater in patients with type 2 endoleak (OR 1.45, 95% CI 1.16-1.56, P < 0.0005). Both variables independently predicted the incidence of type 2 endoleak in a multivariate analysis. Thrombus density was not related to the incidence of type 2 endoleak.

CONCLUSIONS

A lower ratio of thrombus volume/infrarenal aorta volume and a higher number of patent lumbar arteries were associated with an increased incidence of type 2 endoleak. A multivariate logistic regression model was generated to pre-operatively predict the risk of type 2 endoleak. This model can guide the stratification of patients for intensity of endoleak surveillance following EVAR and consideration of pre-operative treatment.