Patients with large neck diameter have a higher risk of type IA endoleaks and aneurysm rupture after standard endovascular aneurysm repair

A Statistical Shape Model of Infrarenal Aortic Necks in Patients With and Without Late Type Ia Endoleak After Endovascular Aneurysm Repair

PURPOSE

Hostile aortic neck characteristics, including short length, severe suprarenal and infrarenal angulation, conicity, and large diameter, have been associated with increased risk for type Ia endoleak (T1aEL) after endovascular aneurysm repair (EVAR). This study investigates the mid-term discriminative ability of a statistical shape model (SSM) of the infrarenal aortic neck morphology compared with or in combination with conventional measurements in patients who developed T1aEL post-EVAR.

MATERIALS AND METHODS

The dataset composed of EVAR patients who developed a T1aEL during follow-up and a control group without T1aEL. Principal component (PC) analysis was performed using a parametrization to create an SSM. Three logistic regression models were created. To discriminate between patients with and without T1aEL, sensitivity, specificity, and the area under the receiver operating characteristic (ROC) curve (AUC) were calculated.

RESULTS

In total, 126 patients (84% male) were included. Median follow-up time in T1aEl group and control group was 52 (31, 78.5) and 51 (40, 62.5) months, respectively. Median follow-up time was not statistically different between the groups (p=0.72). A statistically significant difference between the median PC scores of the T1aEL and control groups was found for the first, eighth, and ninth PC. Sensitivity, specificity, and AUC values for the SSM-based versus the conventional measurements-based logistic regression models were 79%, 70%, and 0.82 versus 74%, 73%, and 0.85, respectively. The model of the SSM and conventional measurements combined resulted in sensitivity, specificity, and AUC of 81%, 81%, and 0.92.

CONCLUSION

An SSM of the infrarenal aortic neck determines its 3-dimensional geometry. The SSM is a potential valuable tool for risk stratification and T1aEL prediction in EVAR. The SSM complements the conventional measurements of the individual preoperative infrarenal aortic neck geometry by increasing the predictive value for late type Ia endoleak after standard EVAR.

CLINICAL IMPACT

A statistical shape model (SSM) determines the 3-dimensional geometry of the infrarenal aortic neck. The SSM complements the conventional measurements of the individual pre-operative infrarenal aortic neck geometry by increasing the predictive value for late type Ia endoleaks post-EVAR. The SSM is a potential valuable tool for risk stratification and late T1aEL prediction in EVAR and it is a first step toward implementation of a treatment planning support tool in daily clinical practice.

Machine Learning Based Prediction of Post-operative Infrarenal Endograft Apposition for Abdominal Aortic Aneurysms

OBJECTIVE

Challenging infrarenal aortic neck characteristics have been associated with an increased risk of type Ia endoleak after endovascular aneurysm repair (EVAR). Short apposition (< 10 mm circumferential shortest apposition length [SAL]) on the first post-operative computed tomography angiography (CTA) has been associated with type Ia endoleak. Therefore, this study aimed to develop a model to predict post-operative SAL in patients with an abdominal aortic aneurysm based on the pre-operative shape.

METHODS

A statistical shape model was developed to obtain principal component scores. The dataset comprised patients treated by standard EVAR without complications (n = 93) enriched with patients with a late type Ia endoleak (n = 54). The infrarenal SAL was obtained from the first post-operative CTA and subsequently binarised (< 10 mm and ≥ 10 mm). The principal component scores that were statistically different between the SAL groups were used as input for five classification models, and evaluated by means of leave one out cross validation. Area under the receiver operating characteristic curves (AUC), accuracy, sensitivity, and specificity were determined for each classification model.

RESULTS

Of the 147 patients, 24 patients had an infrarenal SAL < 10 mm and 123 patients had a SAL ≥ 10 mm. The gradient boosting model resulted in the highest AUC of 0.77. Using this model, 114 patients (77.6%) were correctly classified; sensitivity (< 10 mm apposition was correctly predicted) and specificity (≥ 10 mm apposition was correctly predicted) were 0.70 and 0.79 based on a threshold of 0.21, respectively.

CONCLUSION

A model was developed to predict which patients undergoing EVAR will achieve sufficient graft apposition (≥ 10 mm) in the infrarenal aortic neck based on a statistical shape model of pre-operative CTA data. This model can help vascular specialists during the planning phase to accurately identify patients who are unlikely to achieve sufficient apposition after standard EVAR.

Friendly Neck Anatomy Does Not Prevent Neck-Related Adverse Events After EVAR

BACKGROUND

Life-long follow-up after endovascular aneurysm repair (EVAR) is costly and burdensome to the patient. Follow-up should be stratified based on the risk of EVAR failure. Aneurysm neck is thought to be the single most important risk factor. This study investigated neck anatomy as a predictor of neck-related adverse events after EVAR.

METHODS

This retrospective single-center study included consecutive patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms between 2011 and 2016 (n = 222) who were followed with yearly imaging until December 2020. Hostile neck was defined as neck length ≤15 mm, width ≥28 mm, angulation ≥60°, calcification, or thrombus ≥50% of circumference or conical neck based on preoperative computed tomography angiography. Neck-related adverse event was defined as aneurysm rupture, any neck-related reintervention or type 1a endoleak during follow-up.

RESULTS

Ninety (41%) patients had hostile neck and 132 (59%) had friendly neck. There were no differences in 30-day mortality (1% vs. 1%, P = 0.78), major adverse events (20% vs. 16%, P = 0.43) or reinterventions during the hospital stay (8% vs. 4%, P = 0.20) between patients with hostile and friendly neck. Estimated survival at 1 year was 89 ± 3% for hostile neck and 95 ± 2% for friendly neck patients (P < 0.01). Five-year survival estimates were 51 ± 6% and 66 ± 4%, respectively. Aneurysm-related mortality was higher after 6 years in patients with hostile neck (P < 0.01). Twenty-four patients (11%) suffered neck-related adverse events with mean time-to-event of 3.3 ± 2.8 years; there were no differences between the groups stratified by neck anatomy. Incidentally, preoperative aneurysm diameter was found to be an independent risk factor for neck-related adverse events and aneurysm-related mortality; 53 patients (24%) had aneurysm diameter ≥70 mm, which was associated with nearly 4-fold risk of neck-related complications during the follow-up.

CONCLUSIONS

Friendly neck anatomy may not protect from neck-related adverse events after EVAR in the long-term. Especially patients with large aneurysms should be followed closely.

Long Term Outcomes of the Gore Excluder Low Permeability Endoprosthesis for the Treatment of Infrarenal Aortic Aneurysms

OBJECTIVE

This study evaluated the long term outcomes of endovascular aneurysm repair using the Gore Excluder Low Permeability (LP) endoprosthesis across high volume Dutch hospitals.

METHODS

A retrospective analysis was conducted of patients treated with the Excluder LP for infrarenal abdominal aortic aneurysm (AAA) in four hospitals between 2004 and 2017. Primary outcomes were overall survival, freedom from re-interventions (overall, inside and outside instructions for use, IFU), and AAA sac dynamics: growth (> 5 mm), stabilisation, and regression (< 5 mm). Secondary outcomes were technical success (device deployment), procedural parameters, and re-interventions. Follow up visits were extracted from patient files, with imaging assessed for complications and AAA diameter.

RESULTS

Five hundred and fourteen patients were enrolled, with a median (IQR) follow up of 5.0 (2.9, 6.9) years. Survival rates were 94.0% at one year, 73.0% at five years, and 37.0% at 10 years, with freedom from re-interventions of 89.0%, 79.0%, and 71.0%, respectively. 37.9% were treated outside IFU, leading to significantly more re-interventions over 10 years compared with those treated inside IFU (36.0% vs. 25.0%, respectively; p = .044). The aneurysm sac regressed by 53.5% at one year, 65.8% at five years, and 77.8% at 10 years, and grew by 9.8%, 14.3%, and 22.2%, respectively. Patients with one year sac growth had significantly worse survival (p = .047). Seven patients (1.4%) had a ruptured aneurysm during follow up. Over 15 years, type 1a endoleak occurred in 5.3%, type 1b in 3.1%, type 3 in 1.9%, type 4 in 0.2%, and type 2 in 35.6% of patients.

CONCLUSION

This multicentre study of real world endovascular aneurysm repair data using the Gore Excluder LP endoprosthesis demonstrated robust long term survival and re-intervention rates, despite 37.9% of patients being treated outside IFU, with type 4 endoleak being rare. Treatment outside IFU significantly increased re-intervention rates and one year sac growth was associated with statistically significantly worse survival.

Midterm outcomes of "wide neck" abdominal aortic aneurysm after open or endovascular repair in two European centers: a propensity score matching analysis

BACKGROUND

The aim of this study was to compare mid-term clinical and morphological outcomes in patients undergoing open (OR) and endovascular aortic repair (EVAR) with a proximal wide neck abdominal aortic aneurysm (WN-AAA).

METHODS

Between 2009 and 2014 data of all patients undergoing OR at IRCCS San Raffaele Hospital and EVAR at German Aortic Center Hamburg were retrospectively analyzed. Primary endpoints were aneurysm-related mortality at 5 years, reintervention, and overall mortality. Secondary endpoint was proximal neck enlargement. A 1:1 propensity score matching (PSM) was performed. Survival and freedom from AAA-related reintervention were investigated in matched OR and EVAR group by Kaplan-Meier analysis.

RESULTS

Of all OR performed at IRCCS San Raffaele Hospital 70 were found to have a proximal neck >28 mm (mean age: 69.8±7.2 years, 67 [95.71%] male); of all consecutive EVAR performed at German Aortic Center Hamburg, 52 required an endograft size of at least 32 mm (mean age of 73.1±8.7 years, 49 [94.2%] male). After PSM, the study cohort consisted of 30 OR and EVAR. One early mortality was registered in both groups (P=NS). Mid-term freedom from reintervention compared in OR and EVAR, with no statistically significant differences (P=0.979). Eight (15.4%) patients treated with EVAR developed a significant proximal diameter enlargement (≥3 mm) while only 1 (1.4%) patient in the OR group had the same evolution (P<0.01).

CONCLUSIONS

In WN-AAA neck enlargement is observed more frequently in patients undergoing EVAR, but reintervention rate was similar in the 2 groups, demonstrating that both options were safe and effective.

Insight from an Italian Delphi Consensus on EVAR feasibility outside the instruction for use: the SAFE EVAR Study

BACKGROUND

The SAfety and FEasibility of standard EVAR outside the instruction for use (SAFE-EVAR) Study was designed to define the attitude of Italian vascular surgeons towards the use of standard endovascular repair (EVAR) for infrarenal abdominal aortic aneurysm (AAA) outside the instruction for use (IFU) through a Delphi consensus endorsed by the Italian Society of Vascular and Endovascular Surgery (Società Italiana di Chirurgia Vascolare ed Endovascolare - SICVE).

METHODS

A questionnaire consisting of 26 statements was developed, validated by an 18-member Advisory Board, and then sent to 600 Italian vascular surgeons. The Delphi process was structured in three subsequent rounds which took place between April and June 2023. In the first two rounds, respondents could indicate one of the following five degrees of agreement: 1) strongly agree; 2) partially agree; 3) neither agree nor disagree; 4) partially disagree; 5) strongly disagree; while in the third round only three different choices were proposed: 1) agree; 2) neither agree nor disagree; 3) disagree. We considered the consensus reached when ≥70% of respondents agreed on one of the options. After the conclusion of each round, a report describing the percentage distribution of the answers was sent to all the participants.

RESULTS

Two-hundred-forty-four (40.6%) Italian Vascular Surgeons agreed to participate the first round of the Delphi Consensus; the second and the third rounds of the Delphi collected 230 responders (94.3% of the first-round responders). Four statements (15.4%) reached a consensus in the first rounds. Among the 22 remaining statements, one more consensus (3.8%) was achieved in the second round. Finally, seven more statements (26.9%) reached a consensus in the simplified last round. Globally, a consensus was reached for almost half of the proposed statements (46.1%).

CONCLUSIONS

The relatively low consensus rate obtained in this Delphi seems to confirm the discrepancy between Guideline recommendations and daily clinical practice. The data collected could represent the source for a possible guidelines' revision and the proposal of specific Good Practice Points in all those aspects with only little evidence available.

Large-Diameter Fenestrated Endograft Repair of Abdominal Aortic Aneurysms Is Not Associated With Medium-Term Outcomes

INTRODUCTION

Recent data suggests that infrarenal abdominal aortic aneurysm (AAA) endovascular repair (EVAR) with large diameter grafts (LGs) may have a higher risk of endoleak and reintervention. However, this has not been studied extensively for fenestrated endovascular aneurysm repair (fEVAR). We, therefore, sought to evaluate the outcomes of patients undergoing fEVAR with large-diameter endografts.

METHODS

Patients from the national Vascular Quality Initiative registry who underwent fEVAR for intact juxtarenal AAA were identified. Patients with genetic causes for aneurysms, those with prior aortic surgery, and those undergoing repair for symptomatic or ruptured aneurysms were excluded. Rates of endoleaks and reintervention at periprocedural and long-term follow-up timepoints (9-22 mo) were analyzed in grafts 32 mm or larger (LG) and were compared to those smaller than 32 mm (small diameter graft).

RESULTS

A total of 693 patients (22.8% LG) were identified. Overall, demographic variables were comparable except LG exhibited a more frequent history of coronary artery disease (32.9% versus 25.4%, P = 0.037). There were no significant differences in the rates of endoleak at procedural completion. Overall survival at 5 y was no different. The rate of reintervention at 1 y was also no different (log-rank P = 0.86).

CONCLUSIONS

While graft size appears to have an association with outcomes in infrarenal aneurysm repair, the same does not appear to be true for fEVAR. Further studies should evaluate the long-term outcomes associated with LG which could alter the approach to repair of AAA with large neck diameters traditionally treated with standard infrarenal EVAR.

The Ratio Between the Infrarenal and Suprarenal Aortic Diameter Is a Predictor of Durable Proximal Seal After Endovascular Aneurysm Repair

OBJECTIVES

The aim of this study was to assess whether the ratio of the mean infrarenal neck diameter to the suprarenal aortic diameter is a predictor for a durable proximal seal after endovascular aneurysm repair (EVAR).

METHODS

A total of 439 patients who underwent elective EVAR between 2004 and 2018 in a single vascular referral center met our inclusion criteria. Ratios were calculated by dividing the mean infrarenal neck diameter by 4 different suprarenal aortic diameters. Patients who developed a late type 1A endoleak (n=20) or proximal neck dilatation mandating revision (n=8) were compared with the 411 patients without long-term proximal seal complications.

RESULTS

Patients who developed a late type 1A endoleak had more frequently hypertension, a shorter infrarenal neck length, and a larger mean infrarenal neck diameter. The ratio of the mean infrarenal neck diameter to all 4 suprarenal aortic diameters was higher in the late type 1A endoleak group compared with the group without a late type 1A endoleak. Least absolute shrinkage and selection operator (LASSO) logistic regression identified a combination of 6 variables as the best combination to predict a late type 1A endoleak: presence of hypertension, increased mean infrarenal neck diameter, decreased aneurysm neck length, larger ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the superior mesenteric artery (SMA), larger ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the upper renal artery, and increased β-angle. Of these, based on both the univariate area under the curve (AUC) and optimal LASSO model restricted to a single predictor, the ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the SMA (AUC, 0.770; cutoff value, 0.997) was considered the best prognostic variable.

CONCLUSION

The ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the SMA is a good predictor for a late type 1A endoleak. Patients with mean infrarenal neck diameter larger than the diameter proximal to the SMA (ratio >1) are at risk for a late type 1A endoleak.

CLINICAL IMPACT

In this single-center, retrospective cohort study, we found that the ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the SMA is a good predictor for a late type 1A endoleak. We conclude that the suprarenal diameter must be taken into account before assessing endovascular aortic aneurysm repair eligibility. Patients with a ratio >1 may not be the best candidates for a durable result after EVAR and may be better off with fenestrated EVAR or open repair.

A Ratio Between Infrarenal and Suprarenal Aortic Diameters Corrects for Absolute Aortic Diameter Variations due to Patients' Sex and Body Size

OBJECTIVES

Aortic diameters may differ significantly between patients with different gender and body size. The aim of this study was to relate absolute aortic diameters to age, sex, height, and weight of the patients and to correct for these factors by calculating the ratio between the infrarenal and the suprarenal aortic diameters.

METHODS

A total of 458 patients who underwent elective endovascular aneurysm repair (EVAR) between 2004 and 2018 were included. The aortic anatomy in this group of elective EVAR patients was compared with a control group of 75 patients without an abdominal aortic aneurysm (AAA). The aortic diameter was measured at 4 suprarenal points and 4 infrarenal points. Ratios were calculated by dividing the mean infrarenal neck diameter by 4 suprarenal measurements.

RESULTS

Patients in the aneurysm group had significantly larger suprarenal and infrarenal aortic diameters. The ratios between the mean infrarenal neck diameter and all 4 suprarenal measurements were larger in the AAA group than in the control group. In both groups, there was a significant correlation between the mean infrarenal neck diameter and sex, height, weight, and body surface area (BSA). However, in both groups, all 4 ratios between the mean infrarenal neck diameter and suprarenal aortic diameters were not correlated with age, sex, height, weight, or BSA, except for the ratio between the mean infrarenal neck diameter and the aortic diameter measurement proximal to the upper renal artery, which was correlated to weight and BSA in the control group.

CONCLUSION

The mean infrarenal neck diameter is correlated with sex, height, weight, and BSA. However, when the suprarenal aortic diameter was used as an internal control for the mean infrarenal neck diameter, we were able to correct for these variations in aortic diameters due to sex and body size. The clinical relevance of this ratio in patients treated by EVAR has yet to be assessed in future research.

CLINICAL IMPACT

In the assessment for EVAR suitability the absolute diameter of the aneurysm neck is taken into account. We believe that using absolute diameters is not the appropriate way to assess this suitability, but that patient characteristics such as age, gender and body size, should be factored into this assessment. In this paper, we show that suprarenal and infrarenal aortic diameters are both significantly increased in patients with an aneurysm compared with patients without an aneurysm. Besides, we found that mean infrarenal aortic diameter is correlated with sex, height, weight, and body surface area. Finally, we propose a new ratio system, using suprarenal diameters as an internal control, to correct for aortic diameter variations due to sex and body size.

The Impact of Proximal Neck Anatomy on the 5-Year Outcomes Following Endovascular Aortic Aneurysm Repair With the Ovation Stent Graft

PURPOSE

Hostile proximal neck anatomy has historically been associated with worse outcomes for endovascular aortic aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA). We investigated the impact of proximal neck anatomy on the outcomes following EVAR with the Ovation abdominal stent graft (Endologix, Irving, Calif).

METHODS

We used prospectively collected data from the Effectiveness of Custom Seal with Ovation: Review of the Evidence database, compromised of pooled data from 6 clinical trials and the European Post-Market Registry of patients undergoing elective infrarenal EVAR (2009-2017). We investigated the impact of short neck length (<10 mm), wide neck diameter (≥28 mm), reverse taper shape (>10%), and neck angulation (>45°) on the outcomes. The primary outcome was type IA endoleak. Secondary outcomes included any type I/III endoleak, sac expansion, aneurysm-related reinterventions, and all-cause and aneurysm-related mortality, and a combined endpoint of type IA endoleak, graft migration, AAA-related reintervention, conversion, and aneurysm rupture. We used Kaplan-Meier analysis and Cox proportional hazards models to estimate the 30 day and 5 year rates and assess univariate and risk-adjusted differences.

RESULTS

Of the 1020 patients, 60 patients had a short neck, 113 had a wide neck diameter, 279 were reverse taper shaped, and 99 had neck angulation >45°. Wide proximal neck was associated with higher 5 year type IA endoleak estimates compared with favorable neck anatomy (7.1% vs 4.3%; p=0.02). No association with 5 year type IA endoleak was found for short neck length (1.7% vs 4.3%; p=0.52), reverse taper shape (3.2% vs 4.3%; p=0.99), or neck angulation (6.1% vs 4.3%; p=0.13). A wide neck diameter compared with favorable anatomy was also associated with higher 5 year estimates of graft migration (3.8% vs 0.4%; p=0.03) and the combined neck-related adverse outcome endpoint (16% vs 9.5%; p=0.002). The estimates of aneurysm sac expansion, rupture, and overall and aneurysm-related mortality were similar between the hostile proximal neck anatomy cohorts and favorable anatomy.

CONCLUSION

Wide proximal neck is associated with higher 5 year type IA endoleak rates for patients treated with the Ovation stent graft. However, short neck length, reverse taper shape, and neck angulation are not associated with higher 5 year type IA endoleak rates.

CLINICAL IMPACT

Hostile proximal neck anatomy has historically been associated with worse outcomes for endovascular aortic aneurysm repair of abdominal aortic aneurysms. The Ovation stent graft platform uses a different proximal sealing method using a polymer inflatable ring, aiming to improve sealing between the graft and aortic wall. This study demonstrated that short, angulated, and reverse taper-shaped neck anatomy did not result in increased type IA endoleak estimates in patients treated with the Ovation stent graft platform. Potentially, the different sealing mechanisms played a role in mitigating the historically worse outcomes in patients with short, angulated, and reverse taper-shaped neck anatomy.

A review of current status of cell-based therapies for aortic aneurysms

An aortic aneurysm (AA) is defined as focal aortic dilation that occurs mainly with older age and with chronic inflammation associated with atherosclerosis. The aneurysmal wall is a complex inflammatory environment characterized by endothelial dysfunction, macrophage activation, vascular smooth muscle cell (VSMC) apoptosis, and the production of proinflammatory molecules and matrix metalloproteases (MMPs) secreted by infiltrated inflammatory cells such as macrophages, T and B cells, dendritic cells, neutrophils, mast cells, and natural killer cells. To date, a considerable number of studies have been conducted on stem cell research, and growing evidence indicates that inflammation and tissue repair can be controlled through the functions of stem/progenitor cells. This review summarizes current cell-based therapies for AA, involving mesenchymal stem cells, VSMCs, multilineage-differentiating stress-enduring cells, and anti-inflammatory M2 macrophages. These cells produce beneficial outcomes in AA treatment by modulating the inflammatory environment, including decreasing the activity of proinflammatory molecules and MMPs, increasing anti-inflammatory molecules, modulating VSMC phenotypes, and preserving elastin. This article also describes detailed studies on pathophysiological mechanisms and the current progress of clinical trials.

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

BACKGROUND

There is significant debate regarding the existence of sex-related differences in the presentation, treatment, and outcomes of men versus women affected by abdominal aortic aneurysm (AAA). The purpose of this study is to compare endovascular aneurysm repair (EVAR) of infrarenal AAAs with the current sex-neutral 5.0-5.5 cm-diameter threshold for intervention between the two sexes.

METHODS

Retrospective review of consecutive cases from a single teaching institution over a period of five years of patients who had undergone elective EVAR for AAAs between 5.0 and 5.5 cm in diameter. Outcomes of interest were compared according to sex.

RESULTS

Ninety-four patients were included in the analysis, with a higher prevalence of men (53%). Females were older at the time of repair, 78 ± 5.1 years, versus 71.7 ± 7 years (p < 0.01), and had higher incidence of underlying comorbidities, namely, arrhythmia, chronic kidney disease, and previous carotid revascularization. Women had higher incidence of immediate systemic complications (p = 0.021), post-operative AMI (p = 0.001), arrhythmia (p = 0.006), pulmonary oedema (p < 0.001), and persistent renal dysfunction (p = 0.029). Multivariate analysis for post-operative factors associated to mortality and adjusted for sex confirmed that AMI (p = 0.015), arrhythmia (p = 0.049), pulmonary oedema (p = 0.015), persistent renal dysfunction (p < 0.001), cerebral ischemia (p < 0.001), arterial embolism of lower limbs (p < 0.001), and deep-vein thrombosis of lower limbs (p < 0.001) were associated to higher EVAR-related mortality; a higher incidence of post-operative AMI (p = 0.014), pulmonary edema (p = 0.034), and arterial embolism of lower limbs (p = 0.046) were associated to higher 30-days mortality. In females there was also a higher rate of suprarenal fixation (p = 0.026), insertion outside the instruction for use (p = 0.035), and a more hostile neck anatomy with different proximal aortic diameter (p < 0.001) and angle (p = 0.003).

CONCLUSIONS

A similar threshold of size of AAA for elective surgery for both males and females might not be appropriate for surgical intervention, as females tend to have worse outcomes. Further population-based studies are needed to guide on sex-related differences and intervention on AAA.

Morphological and Clinical Predictors of Early/Follow-up Failure of the Endovascular Infrarenal Abdominal Aneurysm Repair With Currently Available Endografts

PURPOSE

To report outcomes of endovascular repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs) with currently-available endografts and identify predictors of technical/clinical failure.

MATERIALS AND METHODS

Patients undergoing EVAR between 2012 and 2020 were prospectively collected and retrospectively analyzed. Technical success (TS: no type I-III endoleaks, renal/hypogastric arteries loss, iliac leg occlusion, conversion to open repair and mortality within 24 postoperative hour), proximal neck-related TS (nr-TS: no proximal type I endoleaks, unplanned renal arteries coverage), and 30-day mortality were assessed as early outcomes. Proximal type I endoleak (ELIa), survival and freedom from reinterventions (FFRs) were assessed during follow-up. Uni/multivariate analysis and Cox-regression were used to identified factors associated with early and follow-up outcomes; FFR and survival were assessed by Kaplan-Meier analysis.

RESULTS

A total of 710 were included. Technical success and nr-TS were 692 (98%) and 700 (99%), respectively. The presence of ≥2 hostile anatomical infrarenal neck characteristics was associated with technical failure (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.3-4.1; p: 0.007). Infrarenal neck angle >90° (OR: 2.88; 95% CI: 9.6-50.3; p: 0.004), barrel shape (OR: 2.33; 95% CI: 11.1-100.3; p: 0.02) or presence of ≥2 hostile anatomical infrarenal neck characteristics (OR: 2.16; 95% CI: 2.5-5.3; p: 0.03) were independent risk factors for neck-related technical failures. Six (0.8%) patients died within 30 postoperative days. Chronic obstructive pulmonary disease (OR: 16; 95% CI: 1.1-218.3; p: 0.04) and urgent repair (OR: 15; 95% CI: 1.8-119.6; p: 0.01) were independent risk factors for 30-day mortality. The mean follow-up was 53±13 months. There were 12 (1.7%) ELIa during follow-up. Infrarenal neck length <15 mm (hazard ratio [HR]: 2.8; 95% CI: 1.9-9.6; p: 0.005), diameter >28 mm (HR: 2.7; 95% CI: 1.6-9.5; p: 0.006), angle ≥90° (HR: 2.7; 95% CI: 8.3-50.1; p: 0.007), and persistent type II endoleak (HR: 2.9; 95% CI: 1.6-10.1; p: 0.004) were independent risk factors for ELIa. Freedom from reintervention was 91% at 5 years. The ELIa was an independent risk factor for reinterventions during follow-up (HR: 29.5; 95% CI: 1.4-1.6; p<0.001). Survival was 74% at 5 years with 2 cases (0.3%) of late aortic-related mortality. Peripheral arterial occlusive disease (HR: 1.9; 95% CI: 1.4-3.65; p: 0.03), aneurysm diameter ≥65 mm (HR: 2.2; 95% CI: 1.4-3.26; p<0.001), and infrarenal neck length <15 mm (HR: 1.7; 95% CI: 1.2-2.35; p: 0.04) were independent risk factors for mortality during follow-up.

CONCLUSION

Endovascular repair with currently-available endografts has high TS and low 30-day mortality. Survival and FFRs were satisfactory at mid-term. Pre/postoperative risk factors for technical and clinical failure were identified and they should be considered in EVAR indication and postoperative management to reduce complications and improve mid-term outcome.

CLINICAL IMPACT

Pre and postoperative risk factors for technical and clinical EVAR failure can be identified and they should be considered in EVAR indication and postoperative management to reduce complications and improve mid-term outcome.

Endovascular Repair of Abdominal Aortic Aneurysms is a Valid Alternative to Open Repair also in Patients Treated Outside of Instructions for Use Criteria

PURPOSE

It remains unclear whether endovascular aneurysm repair, in the long term, is less effective than open surgery due to need for reinterventions and close monitoring. We aimed to evaluate this matter in a real-life cohort.

METHODS

We collected consecutive patients treated with EVAR or OSR between January 2005 and December 2013. Primary outcomes were 30-day, 90-day and long-term all-cause mortality. Secondary outcomes were 30-day reintervention rate and reintervention-free survival. We evaluated also a subpopulation who did not adhere to IFU.

RESULTS

The inclusion criteria were met by 416 patients. 258 (62%) received EVAR, while 158 (38%) underwent OSR. The 30- or 90-day mortality was similar between groups (p = 0.272 and p = 0.346), as ARM (p = 0.652). The 30-day reintervention rate was higher in the OSR group (p < 0.001), but during follow-up, it was significantly higher in the EVAR group (log-rank: 0.026). There were 114 (44.2%) non-IFU patients in the EVAR group, and we compared them with OSR group. There was no significant difference in all-cause mortality at 30 or 90 days, nor in the long term (p = 1; p = 1 and p = 0.062). ARM was not affected by the procedure technique (p = 0.136). The short-term reintervention rate was higher in the OSR group (p = 0.003), while in the long-term EVAR, patients experienced more reinterventions (log-rank = 0.0.43).

CONCLUSION

No significant difference in survival was found between EVAR and OSR, independent of adherence to IFU. EVAR may be considered for surgical candidates.

Pre-operative Aortic Neck Characteristics and Post-operative Sealing Zone as Predictors of Type 1a Endoleak and Migration After Endovascular Aneurysm Repair: A Systematic Review and Meta-Analysis

OBJECTIVE

Establishing the predictive value of neck characteristics and real achieved sealing zone is essential to foster risk stratified procedure selection and imaging surveillance. This systematic review provides an overview of pre-operative aortic neck characteristics and post-operative real achieved sealing zone and their respective risk of type 1a endoleak and migration after endovascular aneurysm repair (EVAR).

METHODS

In agreement with PRISMA guidelines, MEDLINE, Embase, and Cochrane CENTRAL were searched. Data on neck characteristics, sealing zone, and EVAR outcome were extracted. Meta-analyses were performed to investigate the effect of neck diameter, angulation, and shape on type 1a endoleak (total, early ≤ 90 days, and late > 90 days) and migration in patients who underwent EVAR. A qualitative summary was also provided.

RESULTS

Thirty-three studies were included. Patients with a larger neck diameter had an increased risk of total type 1a endoleak (nine studies: OR 3.32, 95% CI 2.38 - 4.63), early type 1a endoleak (six studies: OR 2.64, 95% CI 1.27 - 5.48), late type 1a endoleak (six studies: OR 3.26, 95% CI 2.12 - 5.03), and migration (seven studies: OR 2.88, 95% CI 1.32 - 6.26). An angulated neck increased the risk of total type 1a endoleak (seven studies: OR 4.27, 95% CI 1.55 - 11.78) and late type 1a endoleak (seven studies: OR 5.56, 95% CI 2.19 - 14.13). Neck shape was not associated with type 1a endoleak. Neck length and real achieved sealing zone on post-EVAR computed tomography were identified as risk factors for type 1a endoleak and migration through qualitative summary.

CONCLUSION

There seems to be some consistent evidence that aortic neck diameter, angulation, and length are associated with the development of type 1a endoleak or migration. Real achieved sealing zone might be an important addition during follow up. However, a small number of studies, with serious limitations, could be included, and there was considerable variability in reporting patients and outcomes. A proposal for standardisation of aortic and EVAR data in future studies is provided.

Is Evar Feasible in Challenging Aortic Neck Anatomies? A Technical Review and Ethical Discussion

Background: Endovascular aneurysm repair (EVAR) has become an accepted alternative to open repair (OR) for the treatment of abdominal aortic aneurysm (AAA) despite “hostile” anatomies that may reduce its effectiveness. Guidelines suggest refraining from EVAR in such circumstances, but in clinical practice, up to 44% of EVAR procedures are performed using stent grafts outside their instruction for use (IFU), with acceptable outcomes. Starting from this “inconsistency” between clinical practice and guidelines, the aim of this contribution is to report the technical results of the use of EVAR in challenging anatomies as well as the ethical aspects to identify the criteria by which the “best interest” of the patient can be set. Materials and Methods: A literature review on currently available evidence on standard EVAR using commercially available endografts in patients with hostile aortic neck anatomies was conducted. Medline using the PubMed interface and The Cochrane Library databases were searched from 1 January 2000 to 6 May 2021, considering the following outcomes: technical success; need for additional procedures; conversion to OR; reintervention; migration; the presence of type I endoleaks; AAA-related mortality rate. Results: A total of 52 publications were selected by the investigators for a detailed review. All studies were either prospective or retrospective observational studies reporting the immediate, 30-day, and/or follow-up outcomes of standard EVAR procedures in patients with challenging neck anatomies. No randomized trials were identified. Fourteen different endo-grafts systems were used in the selected studies. A total of 45 studies reported a technical success rate ranging from 93 to 100%, and 42 the need for additional procedures (mean value of 9.04%). Results at 30 days: the incidence rate of type Ia endoleak was reported by 37 studies with a mean value of 2.65%; 31 studies reported a null migration rate and 32 a null conversion rate to OR; in 31 of the 35 studies that reported AAA-related mortality, the incidence was null. Mid-term follow-up: the incidence rate of type Ia endoleak was reported by 48 studies with a mean value of 6.65%; 30 studies reported a null migration rate, 33 a null conversion rate to OR, and 28 of the 45 studies reported that the AAA-related mortality incidence was null. Conclusions: Based on the present analysis, EVAR appears to be a safe and effective procedure—and therefore recommendable—even in the presence of hostile anatomies, in patients deemed unfit for OR. However, in order to identify and pursue the patient’s best interest, particular attention must be paid to the management of the patient’s informed consent process, which—in addition to being an essential ethical-legal requirement to legitimize the medical act—ensures that clinical data can be integrated with the patient’s personal preferences and background, beyond the therapeutic potential of the proposed procedures and what is generically stated in the guidelines.

[Endovascular aortic repair: the hostile aneurysm neck : Morphologic definition, impact on long-term outcome, and treatment options]

DEFINITION

A hostile neck is defined by various anatomical conditions that describe a morphology of the proximal aneurysmal neck of infrarenal aortic aneurysms that is unfavorable for endovascular treatment (endovascular aortic repair, EVAR): proximal landing zone length ≤ 15 mm, angulation of the aortic neck > 60°, conical aortic neck, diameter of the aortic neck > 32 mm, and circumferential calcification/thrombus.

EFFECTS ON OUTCOME

These morphological parameters are not only associated with a higher perioperative technical failure rate (primary type 1 endoleak) but also with poorer long-term results (secondary type 1 endoleak) and thus a higher reintervention rate in standard EVAR, so that standard EVAR should be reserved for a few exceptions in these cases.

TREATMENT OPTIONS

Due to the rapid development of endovascular techniques in the last decade, we now have a variety of endovascular options for aneurysms with hostile necks, for both elective treatment and emergency care, in addition to conventional open surgery, which is still the standard method in many cases and is currently undergoing a renaissance: fenestrated endovascular aortic repair (FEVAR) as the method of first choice in the elective setting, EVAR with chimneys (ChEVAR), endosuture aneurysm repair (ESAR). An important option is the conservative approach, which can be a reasonable choice if the patient's preference is taken into account and a careful risk-benefit assessment is performed.

Five-year outcomes of the Bi- versus Trimodular EndurantTM stent-graft in 100 patients with infrarenal abdominal aortic repair

BACKGROUND

Recent studies on the Endurant™ endografts mainly compared outcomes of the bimodular stent-graft to other manufacturer's endografts or reported results for cases outside manufacturer's instructions for use (IFU), while data on the experience of standard endovascular aortic repair (EVAR) of infrarenal abdominal aortic aneurysms (AAA) inside manufacturer's IFU comparing the bi- with the trimodular device is limited.

METHODS

Inclusion criteria were: 1) infrarenal aneurysms (>50 mm diameter) treated by Endurant^TM II (END II) or Endurant^TM IIs (END IIs) stent-graft inside manufacturer's IFU; 2) available CTA with 1 mm reconstruction of the entire aorta prior to intervention. Endpoints comparing the devices included technical success, 30-day mortality, rate of complications (bleeding with conversion to open repair, stent-graft stenosis/occlusion, acute distal embolism, infection or postprocedural necessity of dialysis), endoleaks and reinterventions (5-year follow-up). Aneurysm sac diameters were compared between baseline preinterventional CTA and last post-interventional CTA.

RESULTS

One hundred patients (90% male, mean age 74 years) treated with END II (N.=66) or END IIs (N.=34) were included. Technical success was 99%. One procedure-related active bleeding occurred ending up in surgical conversion (END II N.=1). 30d mortality was 0%. No initial type I/III endoleaks were present. Re-interventions were required in 19/100 (19%) of patients (END II N.=10; END IIs N.=9, P=0.17). The outcome of EVAR including technical success, 30d mortality, rate of complications, endoleaks and re-interventions showed no significant differences comparing END II/IIs.

CONCLUSIONS

Five-year outcomes of EVAR show consistently safe and effective results for either END II or IIs device.

A Statistical Shape Model of the Morphological Variation of the Infrarenal Abdominal Aortic Aneurysm Neck

Hostile aortic neck characteristics, such as short length and large diameter, have been associated with type Ia endoleaks and reintervention after endovascular aneurysm repair (EVAR). However, such characteristics partially describe the complex aortic neck morphology. A more comprehensive quantitative description of 3D neck shape might lead to new insights into the relationship between aortic neck morphology and EVAR outcomes in individual patients. This study identifies the 3D morphological shape components that describe the infrarenal aortic neck through a statistical shape model (SSM). Pre-EVAR CT scans of 97 patients were used to develop the SSM. Parameterization of the morphology was based on the center lumen line reconstruction, a triangular surface mesh of the aortic lumen, 3D coordinates of the renal arteries, and the distal end of the aortic neck. A principal component analysis of the parametrization of the aortic neck coordinates was used as input for the SSM. The SSM consisted of 96 principal components (PCs) that each described a unique shape feature. The first five PCs represented 95% of the total morphological variation in the dataset. The SSM is an objective model that provides a quantitative description of the neck morphology of an individual patient.

Tailor-Made Tapering Grafts for Large-Neck Aorta

Patients having a large aortic neck poses a challenge in abdominal aortic aneurysm surgery both in endovascular and open aneurysm repair, sometimes necessitating paravisceral or thoracoabdominal aneurysm repair which carries considerable perioperative risk. Here, we describe techniques of using a tailor-made tapering graft in open surgery that can be adjusted for large neck morphology. This technique helps avoid discrepancies between the proximal aorta and graft, and postoperative acute kidney injury by clamping at lower levels. The conscientious use of this technique in selected patients realizes satisfactory outcomes both in the short term and midterm in the demanding anatomy of large aortic necks.

New Morphological Factor for Predicting Late Proximal Type I Endoleak after Endovascular Aneurysm Repair

BACKGROUND

Although we have witnessed several cases of late proximal type I endoleak (T1AEL) after endovascular aneurysm repair (EVAR), most patients did not have "hostile neck" preoperatively. We hypothesized that the distance between the lowest renal artery and the neck angulation point and neck length are the 2 most important factors for maintaining long-term proximal sealing. This study evaluated "neck hostility," which is the product of the distance to the angulation point and the neck length, as a preoperative morphological risk factor for the development of late T1AEL after EVAR.

METHODS

A retrospective review of a prospectively assembled database was performed for all patients who had undergone EVAR at a single institution from June 2007 to May 2017. Patient demographics and preoperative imaging data were collected, and Cox regression analysis was performed to identify the risk factors for late T1AEL.

RESULTS

Of the 655 patients who underwent EVAR during the study period, 115 were excluded due to complex EVAR (n = 14), primary indications for iliac aneurysms (n = 86), primary T1AEL (n = 3), or other reasons (n = 15). Of the remaining 537 patients, twelve patients (2.2%) developed late T1AEL a median of 3.2 (interquartile range [IQR]; 3.0, 5.4) years after EVAR. Receiver operating characteristic (ROC) curve analysis revealed a neck hostility cutoff value of 8. Cox regression analysis revealed that a neck hostility value ≤8 and conical neck anatomy were risk factors for the development of late T1AEL after EVAR. Well-known hostile neck factors such as short neck, severe angulated neck, and severe calcification/thrombus in the proximal neck were not significantly different.

CONCLUSIONS

The present study demonstrated a correlation between late T1AEL and the product of the angulation distance and the neck length. This factor may be useful for predicting poor late proximal outcomes after EVAR.

Late Type 1A Endoleaks: Associated Factors, Prognosis and Management Strategies

BACKGROUND

Unlike periprocedural Type 1A endoleaks, late appearing proximal endoleaks have been poorly described.

METHODS

We studied all elective EVAR from 2010 -2018 in a single institution. Late endoleaks were defined as those appearing after 1 year. We used Cox regression to study factors associated with late Type 1A endoleaks and survival.

RESULTS

Of 477 EVAR during the study period, 411 (86%) had follow-up imaging, revealing 24 Type 1A endoleaks; 4 early and 20 late. Freedom from Type 1A endoleaks was 99%, 92-81% at 1, 5 and 8 years with a median time to occurrence of 2.5 years (.01-8.2 years). On completion angiogram, only 10% of patients with a late Type 1A had a proximal endoleak, and 60% had no endoleak. Only 21% of late Type 1As were diagnosed on routine 1-year CT angiogram, but 79% had stable or expanding sacs. Two thirds (65%) of the patients eventually diagnosed with late Type 1A endoleaks had previously been treated for other endoleaks, mostly Type 2 (10/13). Age (HR 1.07/year [1.02-1.12], P = 0.01), neck diameter >28mm (HR 3.5 [1.2-10.3], P = 0.02), neck length <20mm (HR 3.0 [1.1-8.6], P = 0.04), and neck angle>60 degrees (HR 3.4 [1.5-7.9], P = 0.004) were associated with higher rates of Type 1A endoleak, but not female sex, endograft, or the use of suprarenal fixation. 2 patients had proximal degeneration and 5 experienced graft migration. There were 2 ruptures (10%), and 13 patients underwent repair with 5 open conversions. Median survival after late Type 1A repair was 6.6 years (0-8.4 years).

CONCLUSION

Late appearing Type 1A endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful surveillance is needed in patients with hostile neck anatomy and those who undergo intervention for other endoleaks. Adverse neck anatomy may be better suited for open repair or fenestrated/branched devices rather than conventional EVAR.

Fenestrated endovascular repair with large device diameters (34- to 36-mm) is associated with type 1 and 3 endoleak and reintervention

OBJECTIVES

 Patients with abdominal aortic aneurysms undergoing EVAR with larger device diameters (34- to 36-mm) have worse outcomes due to proximal fixation failure and need for reintervention. We examine outcomes relating to standard fenestrated repair (FEVAR) with larger device diameters, and investigate whether a similar relationship exists.

MATERIAL AND METHODS

 Retrospective review of a prospectively maintained, single institution database of patients treated with the Cook ZFEN device between 2012-2017. Outcomes were stratified by device diameter into normal-diameter (ND,≤ 32 mm) and large-diameter (LD,34-36 mm). Primary endpoints were need for reintervention and composite type I/III endoleak.

RESULTS

 100 consecutive patients treated were identified for inclusion. Overall mean age was 73.6 years and mean aortic diameter was 59.1 mm. Mean follow-up was 22 months. A total of 26 (26%) patients were treated with LD devices. Number of target vessels per patient was 2.8 in both groups. Infrarenal neck length and diameter were significantly different in the LD and ND patients, respectively (2.6 mm vs 4.7 mm (P<.01) and 30.1 mm vs 23.4 mm (P<.01)). Percent graft oversizing was lower in the LD cohort (19% vs 24%; P=.006). No difference was seen in overall mortality at 30-days (0% vs 2%; P=.4) or at latest follow up (6% vs 14%; P=.6). Reinterventions were not significantly different at 30 days, but were significantly higher over the follow-up period in the LD cohort (46.2 vs. 17.6%; P=.002). LD diameter was associated with reintervention on univariate (HR 1.19, 95% CI 1.04-1.37), but not multivariate analysis. The composite endpoint of type I/III endoleak was higher in the LD cohort (15.4% vs. 2.7%; P=.004).

CONCLUSION

 FEVAR requiring 34- or 36-mm device diameters is associated with an increased risk of composite type I/III endoleak and reintervention. Patients undergoing fenestrated repair requiring LD devices should be closely monitored, with consideration for proximal or open repair.

The combined use of thoracic and abdominal aortic stent grafts for endovascular repair of wide neck abdominal aortic aneurysms in high risk patients

INTRODUCTION

Treatment of abdominal aortic aneurysms (AAA) with large (28 mm to 34 mm) and wide diameter (> 35 mm) necks remains a challenge in patients who are high-risk candidates for open repair. While several case reports describe the use of a thoracic stent graft in conjunction with a traditional modular bifurcated stent graft, most patients do not have the aortic length to accommodate such a configuration. We present our experience utilizing a distal unibody bifurcated aortic stent graft (Endologix, Irvine, CA) in conjunction with a proximal thoracic aortic stent graft (Medtronic, Minneapolis, MN) to treat wide-necked non-ruptured AAAs in patients who were otherwise poor candidates for open or fenestrated repair.

METHODS

A single center retrospective review of patients treated with a combination of a distal unibody bifurcated aortic stent graft and a proximal thoracic aortic stent graft extension from 2013 to 2019 was performed. Demographics, perioperative details and long-term outcomes were collected and summarized. Standard statistical methods were utilized.

RESULTS

We identified 7 patients who underwent this procedure during the study interval. Of these, all 7 (100%) were male with an average age of 69.1 ± 5.1 years. Average Charlson Comorbidity Index was 5.0. Average pre-operative maximum aortic and neck diameters were 57.9 mm (± 5.8) and 37.4 mm (± 4.5) respectively. All patients underwent repair with a distal 28 mm diameter unibody bifurcated aortic stent graft and proximal extension with a thoracic aortic stent graft that ranged from 40 to 46 mm in diameter. Technical success was achieved in all 7 patients. There were no perioperative mortalities or aorta-related deaths. Follow up was a mean of 1.98 years with a mean survival of 4.75 years (± 0.86). One patient required an aneurysm-related intervention for a late type III endoleak.

CONCLUSION

The combined use of thoracic and abdominal aortic stent grafts is a safe and effective endovascular method to treat high-risk surgical candidates with wide-necked AAAs.

Comparison of treatment options for aortic necks outside standard endovascular aneurysm repair instructions for use

OBJECTIVE/BACKGROUND

Endovascular aneurysm repair (EVAR) is associated with worse outcomes in patients whose anatomy does not meet the device instructions for use (IFU). However, whether open surgical repair (OSR) and commercially available fenestrated EVAR (Zenith Fenestrated [ZFEN]) represent better options for these patients is unknown.

METHODS

We identified all patients without prior aortic surgery undergoing elective repair of abdominal aortic aneurysms with neck length ≥4 mm at a single institution with EVAR, OSR, and ZFEN. We applied device-specific aneurysm neck-related IFU to EVAR patients, and a generic EVAR IFU to ZFEN and OSR patients. Long-term outcomes were studied using propensity scores with inverse probability weighting. We compared outcomes in patients undergoing EVAR by adherence to IFU and outcomes by repair types in the subset of patients not meeting IFU.

RESULTS

Of 652 patients (474 EVAR, 34 ZFEN, 143 OSR), 211 had measurements outside of standard EVAR IFU (109 EVAR [23%], 27 ZFEN [80%], and 74 OSR [52%]). Perioperative mortality was 0.5% overall. For EVAR, treatment outside the IFU was associated with significantly higher adjusted rates of long-term type IA endoleak (22% at 5 years compared to 2% within IFU, hazard ratio [HR]: 5.8 [3.1-10.9], P < .001), and lower survival (5- and 10-year survival: 56% and 34% vs 81% and 53%, HR: 2.3 [1.2-4.3], P = .01). There was no difference in reinterventions or open conversion. In patients not meeting IFU, ZFEN was associated with higher adjusted rates of reinterventions (EVAR as referent: HR: 2.6 [1.5-4.4, P < .001), whereas OSR and EVAR patients experienced similar reintervention rates (HR: 0.7 [0.4-1.1], P = .13). Patients outside the IFU experienced lower mortality with OSR compared with either EVAR (HR: 0.4 [0.2-0.9], P = .005) or ZFEN (HR: 0.3 [0.1-0.7], P = .002). When restricted to patients outside the IFU deemed fit for open repair, OSR patients remained associated with lower adjusted mortality compared with ZFEN (HR: 0.2 [0.1-0.5], P < .001), but statistical significance was lost in the comparison to EVAR (HR: 0.6 [0.3-1.1], P = .1).

CONCLUSIONS

Treatment outside device-specific IFU is associated with adverse long-term outcomes. Open surgical repair is associated with higher long-term survival in patients who fall outside of the EVAR IFU and should be favored over EVAR or ZFEN in suitable patients. A three-vessel-based fenestrated strategy may not be a durable solution for difficult aortic necks, but more data are needed to evaluate the performance of newer, four-vessel devices.

Systematic review of embolization of type I endoleaks using liquid embolic agents

OBJECTIVE

The long-term success of endovascular aneurysm repair (EVAR) is limited by complications, most importantly endoleaks. In case of (persistent) type I endoleak (T1EL), secondary intervention is indicated to prevent secondary aneurysm rupture. Different treatment options are suggested for T1ELs, such as endo anchors, (fenestrated) cuffs, embolization, or open conversion. Currently, the treatment of T1EL with liquid embolic agents is available; however, results are not yet addressed. This review presents the safety and efficacy of embolization with liquid embolic agents for treatment of T1ELs after EVAR.

METHODS

A systematic literature search was performed for all studies reporting the use of liquid embolic agents as monotherapy for treatment of T1ELs after EVAR. Patient numbers, technical success (successful delivery of liquid embolics in the T1EL) and clinical success (absence of aneurysm related death, endoleak recurrence or additional interventions during follow-up) were examined.

RESULTS

Of 1604 articles, 10 studies met the selection criteria, including 194 patients treated with liquid embolics; 73.2% of the patients were male with a median age of 71 years. The overall technical success was 97.9%. Clinical success was 87.6%. Because the median follow-up was only 13.0 months (range, 1-89 months), data on long-term success are almost absent. Four cases (2.1%) of secondary aneurysm rupture after embolization owing to endoleak recurrence were reported. All ruptures occurred in aneurysms exceeding initial treatment diameter of 70 mm.

CONCLUSIONS

Initial technical success after liquid embolization for T1EL is high, although long-term clinical success rates are lacking. Within this review, the risk of secondary rupture is comparable with untreated T1EL at 2% with a median follow-up of 13 months, regardless of the initial success of embolization. In general, no decrease in secondary aneurysm rupture after embolization of T1EL after EVAR is demonstrated, although the results of late embolization are debated.

A Novel Solution to Concomitant Type Ia/Type IIIa Endoleak Using the Cook Zenith Fenestrated Device and Endologix AFX®2

Failing EVAR is typically treated with open explant or conversion to fenestrated endovascular repair. Novel solutions for EVAR salvage may be required in patients unable to tolerate explant or travel to centers with custom-fenestrated capabilities. However, strategies utilizing commercially available devices are often limited by anatomic constraints such as short renal artery to endograft bifurcation length. We present a case of progressive sac expansion due to late, concomitant type Ia and type IIIa endoleaks. The patient was successfully treated by proximal extension into the visceral segment using a Cook Zenith Fenestrated device and graft relining using the Endologix AFX^®2.

Ten-year single center experience in elective standard endovascular abdominal aortic aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) has become the treatment of choice for abdominal aortic aneurysm (AAA), demonstrating excellent early outcomes. However, EVAR durability has been questioned in the long-term period. The aim of this study was to assess EVAR outcomes in terms of survival and freedom from re-intervention during a long-term period.

METHODS

All consecutive patients being treated, with elective standard EVAR, in a single tertiary center, were included between 2008 and 2018. Outcomes were defined as survival and freedom from re-intervention and were reported using Kaplan-Meyer lifetables. In subgroup analyses, sex, age (threshold at 65 and 80 years), neck diameter>28mm and type of fixation were also analyzed. Type of re-intervention and endoleak type I (ETIa) were also reported.

RESULTS

Five hundred and eight patients (94% males, mean age 72±7.3, mean AAA diameter 59±9mm) were included. The median follow-up was 3 years (range 0-10 years). The survival rate was 92.8% (SE 1.5%), 76.5% (SE 3.1%) and 41.6% (SE 6%), at 2, 5 and 10 years of follow-up, respectively. In total, 78 patients died; 8 deaths (8/75, 10%) were aneurysm related. In multivariate regression analysis, age (CI. 1.02-1.14; p=0.006) and ever tobacco use (CI. 1.02-6.12, P=0.045) were associated with the long-term mortality. Freedom from re-intervention was 96% (SE 1.1%), 93% (SE 1.8%), 85.5% (SE 5%) at 2, 5 and 9 years of follow-up. Limb occlusion was a common complication (n/n; 30% of re-intervention), particularly within the first 2 postoperative years. Six patients presented with rupture and were treated with open conversion. EVAR cases with supra-renal fixation graft presented lower rates of ETIa (CI. 76-87.27, P<0.001).

CONCLUSIONS

Elective standard EVAR is associated with good long-term survival showing low aneurysm-related mortality. Common risk factors such as advanced age and smoking are associated to higher mortality. The procedure presents low re-intervention rates, while limb occlusion is a complication presented within the first 2 postoperative years.

Systematic review and meta-analysis of endovascular abdominal aortic repair in large diameter infrarenal necks

OBJECTIVE

The aim of this study was to perform a meta-analysis of relevant published literature to investigate the impact of wide proximal aortic neck diameter on outcomes of endovascular aneurysm repair (EVAR) for the repair of abdominal aortic aneurysm (AAA).

METHODS

A systematic literature review was performed to examine the rate of clinical safety and effectiveness end points associated with wide proximal aortic neck diameter after EVAR for the treatment of AAA. A literature search was performed on August 9, 2019, using PubMed as the primary database and Cochrane as the secondary database. In all, there were 11 full articles included in the quantitative and qualitative analyses.

RESULTS

There was a total of 7448 patients who were treated for AAA with EVAR. Of these, 26.9% of patients were defined as having wide necks by the individual publications. The definition of wide neck varied in the literature and ranged from 25 mm or greater to 30 mm or greater. The percentage of male patients was 89.1% in the included articles. The mean or median age range was 72.7 to 76.5 years, which was similar for the wide and normal neck groups. Follow-up ranged from 2 to 5 years. Type I and Ia endoleaks occurred at a higher rate in the wide neck group compared with the normal neck group (11.3% vs 3.1%; P < .001). There was no difference in the rate of type Ib endoleaks between the wide and normal neck groups. The weighted averages of composite major adverse events and aneurysm-related mortality were all greater in the wide neck group (33.5% and 15.3%, respectively) compared with the normal neck group (21.2% and 3.9%, respectively) (P = .004).

CONCLUSIONS

The rates of type Ia endoleaks, reinterventions, and migrations were all significantly higher in the wide neck patient group compared with patients with normal aortic neck size through follow-up. The results of this literature review showed that, although EVAR for the treatment of AAA in patients with a wide aortic neck is feasible, there is a higher risk for complications, interventions, and mortality. In particular, type Ia endoleak is a risk, which could be mitigated by using proximal seal strategies.

Infrarenal Abdominal Aortic Aneurysm Endovascular Treatment: Long-term Results From a Single-Center Experience in an Unselected Patient Population

BACKGROUND

The aim of the present study was to evaluate early-, mid-, and long-term outcomes in an unselected population of patients treated for abdominal aortic aneurysms (AAAs) by endovascular aneurysm repair (EVAR) with different commercially available off-the-shelf devices.

MATERIALS AND METHODS

A retrospective study was conducted on a prospectively compiled computerized database on patients presenting an infrarenal AAA treated between January 2008 and December 2015 in a high-volume Italian tertiary referral Center. Demographic, clinical, and specific morphological features were considered as potentially influencing the outcomes and the type of the implanted device. Outcome measures were procedure-related reintervention, AAA-related, and all-cause mortality rates at 30-day, 12-month, and long-term follow-up. Reinterventions considered for the analysis were AAA rupture, graft infection, type I or III endoleaks, type II endoleaks with sac enlargement > 5 mm, graft stenosis or occlusions, procedures related to renal or visceral ischemia, and reintervention for access vessel injury.

RESULTS

Of 498 EVAR procedures performed for elective infrarenal AAA treatment during the entire study period, 479 patients were enrolled, the mean age was 73.5 ± 7.34 years (range 51-91), and 416 (86.84%) were men. The mean maximum AAA diameter was 52.02 ± 8.04 mm (range 39-90.2), a maximum AAA diameter ≥59 mm was recorded in 107 patients (22.33%), and an aortic neck length was <10 mm in 137 (28.60%). Technical success was achieved in all patients. At a mean follow-up of 52.97 ± 26.16 months (range 1-120), overall reintervention and death rates were 8.14% and 20.04%, respectively, without AAA-related deaths. At univariate analysis, hypertension was the only demographical variable found to be associated with higher risk of reintervention, P = 0.04 (OR: 2.34; CI 95%: 1.00-5.42). Furthermore, male sex (P = 0.02; OR: 2.62; CI 95%: 1.09-6.27) and chronic renal insufficiency (P = 0.003; OR: 2.08; CI 95%: 1.27-3.42) were associated with higher mortality rates. AAA diameter ≥59 mm was statistically associated with a higher rate of both reintervention and mortality: P < 0.001 (OR: 9.05; CI 95%: 4.52-18.11) and <0.001 (4.00; 2.46-6.49), respectively.

CONCLUSIONS

Our experience seems to suggest that EVAR could be safely and effectively performed in an unselected patients' population, with encouraging results up to a ten-year follow-up.

Prognostic significance of large diameter proximal aortic neck in endovascular aneurysm repair

Background: Adverse morphological features of the proximal aortic neck have been identified as culprits for late failure after endovascular aneurysm repair (EVAR). Our objective was to investigate the prognostic role of wide proximal aortic neck in EVAR. Methods: We conducted a review of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies comparing outcomes of EVAR in patients with large versus small proximal aortic neck. A meta-analysis of time-to-event data was performed with the inverse-variance method and the results were reported as summary hazard ratio (HR) and 95 % CI. We applied random-effects models of meta-analysis. Results: We identified 9 observational studies reporting on a total of 7,682 patients (1,961 with large diameter and 5,721 with small diameter neck). The hazard of death (HR 1.57, 95 % CI 1.23-2.01; P = 0.0003), aneurysm-related reintervention (HR 2.06, 95 % CI 1.23-3.45; P = 0.006), type Ia endoleak (HR 6.69, 95 % CI 4.39-10.20; P < 0.001), sac expansion (HR 10.07, 95 % CI 1.80-56.53; P = 0.009), aneurysm rupture (HR 2.96, 95 % CI 2.00-4.38; P < 0.0001), and neck-related adverse events (HR 10.33, 95 % CI 4.95-21.56; P < 0.0001) was higher in patients with large diameter proximal aortic neck than in those with small neck. Conclusions: Patients with a large proximal aortic neck were found to have poorer outcomes than those with small neck. This finding has implications in decision making when selecting methods for aneurysm treatment and in EVAR surveillance for aneurysm-related complications in this cohort of patients.

Endovascular aneurysm repair in patients with a wide proximal aortic neck: a systematic review and meta-analysis of comparative studies

INTRODUCTION

The aim was to investigate the impact of wide proximal aortic diameter on outcome after standard endovascular repair (sEVAR) of infrarenal abdominal aortic aneurysms.

EVIDENCE ACQUISITION

A systematic search of the literature was undertaken using the PUBMED, EMBASE, and Cochrane databases for articles comparing outcome after sEVAR in patients with large versus small diameter aortic neck. The prognostic factor of interest was large diameter proximal aortic neck and the results were reported as odds ratio (OR) or mean difference (MD) and 95% confidence interval (CI). A time-to-event data meta-analysis for late outcomes was performed using the inverse-variance method and reported the results as summary hazard ratio (HR) and 95% CI.

EVIDENCE SYNTHESIS

We identified 6 observational studies reporting on a total of 6602 patients (1616 with large and 4986 with small diameter neck). Patients with large proximal aortic neck were older (MD 0.87, 95% CI: 0.35-1.39; P=0.001). The prevalence of male gender (OR=1.63, 95% CI: 1.34-1.98; P<0.001), coronary artery disease (OR=1.20, 95% CI: 1.06-1.36; P=0.004), chronic obstructive pulmonary disease (OR=1.18, 95% CI: 1.03-1.36; P=0.02) and chronic kidney disease (OR=1.43, 95% CI: 1.23-1.66; P<0.001) was higher in the wide neck group. Patients with large diameter proximal neck had shorter proximal neck (MD=-1.91, 95% CI: -2.04 to -1.77; P<0.001) and a larger aneurysm diameter compared to those with small diameter neck (MD=3.40, 95% CI: 2.71-4.10; P<0.001). Patients with small diameter proximal neck had significantly higher freedom from aneurysm-related reintervention (HR=2.06, 95% CI: 1.23-3.45; P=0.006), freedom from type Ia endoleak (HR=6.69, 95% CI: 4.39-10.20; P<0.001), freedom from sac expansion (HR=10.07, 95% CI: 1.80-56.53; P=0.009), freedom from aneurysm rupture (HR 5.10, 95% CI: 1.40-18.58; P=0.01), and survival (HR=1.55, 95% CI: 1.08-2.24; P=0.02).

CONCLUSIONS

Patients with a wide proximal aortic neck undergoing standard EVAR were found to have worse outcome, as indicated by a lower freedom from aneurysm-related reintervention, type Ia endoleak, sac expansion and aneurysm rupture, and a higher overall survival. This anatomic characteristic should be considered in decision making. In such patients, closer imaging surveillance after EVAR in the long term may be required to identify early and treat timely the complications.