Planning and Endograft Related Variables Predisposing to Late Distal Type I Endoleaks

Risk factors for iliac limb migration after endovascular infrarenal aortic repair

This study investigated anatomical and procedural factors influencing iliac limb migration and its correlation with late type 1b and type 3 endoleaks. We analyzed data of 141 iliac limbs from 91 patients who underwent endovascular aneurysm repair for infrarenal abdominal aortic aneurysm between 2005 and 2017. Iliac limb migration was measured using initial and follow-up computed tomography angiography scans conducted at least three years post-procedure, with significant migration defined as a change of ≥ 5 mm. The iliac limbs were classified into Group 1 (G1; n = 34 limbs, 26 patients) with significant migration and Group 2 (G2; n = 107 limbs, 65 patients) without significant migration. The median follow-up periods were 70.5 months (interquartile range 49.7-91.8 months) for G1 and 57.6 months (interquartile range 44.2-73.2 months) for G2. Multivariable analysis confirmed that significant migration correlated with larger common iliac artery (CIA) diameters and lower iliac limb oversizing. Significant iliac limb migration was associated with a higher risk of type 1b endoleak development. Our findings suggest that careful iliac limb oversizing is essential for patients with a CIA diameter > 20 mm, and vigilant monitoring of the iliac landing zone is crucial during postoperative surveillance.

Distal Landing Zone-Related Complications of Conventional Endovascular Aneurysm Repair (EVAR) in the Long Term: A Comprehensive Systematic Review

The aim of this systematic review is to evaluate the late-onset complications considering the distal landing zones (DLZ) in patients with abdominal aortic aneurysm (AAA) treated by conventional endovascular aneurysm repair (EVAR). We conducted a systematic review of electronic databases, clinical trial registries, and grey literature to retrieve studies on this issue. The inclusion criteria could be summarized as follows: (1) observational studies or case series with more than 30 patients included, (2) at least three-year follow-up, and (3) endpoints including endoleak type Ib (ELIB) or cranial iliac limb migration/retraction (CLR) or DLZ failure-related reinterventions or other complications. Of the 517 potentially eligible studies, the detailed search revealed eight articles with a total of 2569 patients for further investigation. Due to the extreme heterogeneity in definitions and reporting outcomes among the included studies, the synthesis and meta-analysis of data were not plausible. A quantitative assessment of reported outcomes revealed a pooled incidence of 2.1% for ELIB, 1.7% for CLR, and 5.7% for DLZ failure-related reinterventions. Data were considered controversial to extract a consensus for the dilatation of the DLZ. This systematic review delineates the importance of late-onset complications originating from DLZ failures for the longevity of an EVAR procedure and gathers the current knowledge regarding the magnitude and clinical implications of DLZ failure from the existing literature and in the best available quality. Current literature data show a blurred image regarding the long-term morphological alterations of iliac arteries and especially in the impact of DLZ dilatation and emphasize the necessity of prolonged follow-up for at least five years.

The Long-Term Progression of Aneurysmal Disease in Common Iliac Arteries After Standard EVAR and Its Clinical Implications

Introduction: The progression of aneurysmal disease in the common iliac arteries (CIAs) after EVAR remains an insufficiently investigated field. The purpose of this study is to investigate the long-term outcomes of standard elective EVAR with a variety of last-generation bifurcated aortic endografts in relation with the progression of aneurysmal disease in the CIAs. Methods: This is a prospective cohort study of 168 patients, who were treated with six different endografts between 2013 and 2018 and completed the 5-year computed tomography aortoangiography (CTA) follow-up. Postoperative CTA analysis included CIA measurements at four diameters' points and two length levels in three postoperative time spots: first, 24th, and 60th months. All EVAR-related adverse events were recorded, including migrations, endoleaks, limb occlusions, reinterventions, ruptures, and mortality. Results: At both time intervals, a significant and nearly linear dilatation and elongation of CIAs was evident. The mean percent increase, among all diameter points measured, was 11.7% at 24 months and 22.8% at 60 months (p < 0.001) with a nearly constant mean increase rate by 0.07 mm per month. The corresponding monthly elongation rate of total CIA length was 0.26 mm at 24 months and 0.34 mm at 5 years (p < 0.001). The respective monthly lengthening of CIAs' uncovered (from stent graft) segment was 0.10 and 0.15 mm, and the overall increase rate at 60 months was up to 53.9% (p < 0.001). A total of 20 EVAR-related events were recorded, and multivariate analysis revealed that CIA dilatation served as a significant and independent predictor of long-term EVAR failures, increasing the likelihood of adverse events by 2.8-fold. Conclusions: Analysis of long-term geometric CIA remodeling after a standard EVAR revealed a significant progression of aneurysmal disease in CIAs, which was associated with worsening EVAR outcomes and emphasizes the importance of a rigorous and extensive follow-up protocol to maintain the long-term EVAR effectiveness.

Incidence, Risk Factors, and Prognostic Impact of Type Ib Endoleak Following Endovascular Repair for Abdominal Aortic Aneurysm: Scoping Review

OBJECTIVE

The primary objectives of this scoping review were to assess the rate of and risk factors for type Ib endoleak and to evaluate the extent of the evidence base that links type Ib endoleak to short and long term outcomes in patients undergoing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA).

METHODS

Potentially eligible studies were searched in the Cochrane Central Register of Controlled Trials, MEDLINE, Web of Science Core Collection, SciELO Citation Index, Russian Science Citation Index, and KCI-Korean Journal Database. A scoping review was performed according to PRISMA extension for Scoping Reviews.

RESULTS

A total of 27 articles (four prospective registries and 23 retrospective cohort studies) dealing with type Ib endoleak were included in the final analysis. The number of patients reported on was 7 197, with follow up ranging between 12 months and 93 months. The reported frequency of type Ib endoleak in patients treated with EVAR ranged from 0% to 8%, Patient and or procedure related factors associated with risk of type Ib endoleak were (1) common iliac artery (CIA) diameter ˃ 18 mm requiring use of flared stent graft limbs (FLs) ˃ 20 mm, (2) length of CIA landing zone ˂ 20 mm, (3) marked iliac tortuosity, and (4) large initial AAA diameter. Depending on the study, 50 - 100% of type Ib endoleaks were corrected by endovascular means, with a reported immediate technical success of 100% in the studies providing this information.

CONCLUSION

Type Ib endoleak after EVAR has been reported to occur in 0 - 8% of cases. Several anatomical features, including CIA diameter ˃ 18 mm or requiring the use of FLs ˃ 20 mm, length of CIA landing zone ˂ 20 mm, marked iliac tortuosity, and large initial AAA diameter, could increase the risk of type Ib endoleak and may require alternative therapeutic options and or more stringent follow up. Therefore, this updated scoping review provides a comprehensive summary of the frequency, risk factors, prognosis, and treatment of type Ib endoleaks, and has identified knowledge gaps in the literature to guide further studies.

Age and Oversizing Influence Iliac Dilatation after EVAR

In the past two decades, endovascular aortic repair (EVAR) of abdominal aortic aneurysm (AAA) has become the first line treatment for infrarenal AAA repair in many countries. While short-term results are good, concerns have been raised about long-term durability. Changes in aortoiliac anatomy, especially at the landing zones, could play a role in EVAR failure over time. The current study aimed to determine certain morphological changes in the distal iliac landing zone after EVAR implantation, as well aspossible risk factors associated with iliac sealing failure. In a retrospective analysis of a tertiary single-centre registry, including patients treated with EVAR between January 2008 and July 2018, clinical follow-up data were assessed, and computer tomography (CT) imaging was evaluated regarding morphological changes in the iliac anatomy during follow-up. For clinical analysis all patients with a minimum follow-up of one year were included; for morphological analysis of iliac anatomy all patients with available CT follow-up of a minimum of one year and a minimum of two CT scans were included. Overall, 127 out of 241 treated patients (92.1% male) were included in the clinical follow-up. Complete CT imaging of 99 iliac arteries in 55 patients was available for morphological analysis. Median postoperative follow-up (FU) for these patients was 33 months (IQR 31; min−max: 12−124). Incidence of type 1b endoleak was 3% but iliac limb detachment from the vessel wall was seen in 18.2% of the target vessels. There was a significant difference in oversizing in iliac limbs with detachment (median 13.9%, IQR 23.1) vs. without detachment (median 23.1%, IQR 19.1) (p = 0.034). Iliac arteries at the landing zone showed a significant diameter increase independent of an endoleak presence (overall cohort median diameter increase at one year 23.1 mm; at two years 0 mm; at three years 4.9 mm). Iliac arteries with detachment (median 14.4%; IQR 23.9) showed a significantly higher diameter increase at the landing zone after four years compared to arteries without detachment (median 5.3%; IQR 9) (p = 0.042). Oversizing correlated positively with an iliac diameter increase at the landing zone over time (3 m: p= 0.001; one year: p < 0.001; two years: p < 0.001; three years: p = 0.006). Older patients showed a significantly lower diameter increase at the distal landing zone over time than younger patients in the first two years after EVAR (p < 0.001/r = −0.606 after two years). In the current study, iliac limb oversizing was associated with increased dilatation of the distal landing zone during a three-year follow-up, while iliac limb detachment was observed less often. An older age was inversely associated to the iliac diameter increase. Future studies should clarify the association between stent graft oversizing, age, and changes in the iliac anatomy in order to identify parameters that affect EVAR durability.

Development and Comparison of Multimodal Models for Preoperative Prediction of Outcomes After Endovascular Aneurysm Repair

Objective

The aim of this study was to develop and compare multimodal models for predicting outcomes after endovascular abdominal aortic aneurysm repair (EVAR) based on morphological, deep learning (DL), and radiomic features.

Methods

We retrospectively reviewed 979 patients (January 2010—December 2019) with infrarenal abdominal aortic aneurysms (AAAs) who underwent elective EVAR procedures. A total of 486 patients (January 2010–December 2015) were used for morphological feature model development and optimization. Univariable and multivariable analyses were conducted to determine significant morphological features of EVAR-related severe adverse events (SAEs) and to build a morphological feature model based on different machine learning algorithms. Subsequently, to develop the morphological feature model more easily and better compare with other modal models, 340 patients of AAA with intraluminal thrombosis (ILT) were used for automatic segmentation of ILT based on deep convolutional neural networks (DCNNs). Notably, 493 patients (January 2016–December 2019) were used for the development and comparison of multimodal models (optimized morphological feature, DL, and radiomic models). Of note, 80% of patients were classified as the training set and 20% of patients were classified as the test set. The area under the curve (AUC) was used to evaluate the predictive abilities of different modal models.

Results

The mean age of the patients was 69.9 years, the mean follow-up was 54 months, and 307 (31.4%) patients experienced SAEs. Statistical analysis revealed that short neck, angulated neck, conical neck, ILT, ILT percentage ≥51.6%, luminal calcification, double iliac sign, and common iliac artery index ≥1.255 were associated with SAEs. The morphological feature model based on the support vector machine had a better predictive performance with an AUC of 0.76, an accuracy of 0.76, and an F1 score of 0.82. Our DCNN model achieved a mean intersection over union score of more than 90.78% for the segmentation of ILT and AAA aortic lumen. The multimodal model result showed that the radiomic model based on logistics regression had better predictive performance (AUC 0.93, accuracy 0.86, and F1 score 0.91) than the optimized morphological feature model (AUC 0.62, accuracy 0.69, and F1 score 0.81) and the DL model (AUC 0.82, accuracy 0.85, and F1 score 0.89).

Conclusion

The radiomic model has better predictive performance for patient status after EVAR. The morphological feature model and DL model have their own advantages and could also be used to predict outcomes after EVAR.

Effect of limb oversizing on the risk of type Ib endoleak in patients after endovascular aortic repair

OBJECTIVE

We assessed the association between the degree of limb oversizing and the risk of type Ib endoleak (TIBEL) in different types of iliac landing zones after endovascular aortic aneurysm repair.

METHODS

We performed a retrospective cohort study of patients who had undergone endovascular aortic aneurysm repair with bifurcated and limb endografts in an academic center. The main exposure was the degree of limb oversizing. The primary outcome was the occurrence of TIBELs. The secondary outcomes included limb occlusion, reintervention, and overall survival. Subgroup analyses stratified by ectatic and normal iliac landing zones were performed. Multivariate Cox regression analysis and sensitivity analyses using marginal structure model were conducted to adjust for potential confounders.

RESULTS

A total of 750 patients with 1500 iliac limb endografts were included in our study (817 limbs with oversizing of ≤10% and 683 with oversizing >10%). The median 1-year freedom from TIBEL was 98.9% (interquartile range [IQR], 98.0%-99.8%) for limbs with oversizing of ≤10% and 99.6% (IQR, 99.0%-100%) for limbs with oversizing >10%. The median 3-year freedom from TIBEL was 95.6% (IQR, 93.1%-98.1%) and 98.2% (IQR, 96.5%-99.9%) for oversizing ≤10% and >10%, respectively. We found that limb oversizing >10% was associated with a significantly decreased risk of TIBEL (adjusted hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.19-0.76) in the overall population. After stratification by ectatic iliac landing zone, we found that limb oversizing >10% was associated with a significantly decreased risk of TIBEL in the ectatic iliac landing zones (adjusted HR, 0.38; 95% CI, 0.16-0.88). However, no significant difference was found in the limb endografts landing in normal iliac arteries (adjusted HR, 0.44; 95% CI, 0.13-1.45). In the subgroup of normal iliac arteries, we observed a significantly increased risk of limb occlusion in the limbs with distal oversizing >15% compared with the limbs with distal oversizing of ≤15% (adjusted HR, 4.66; 95% CI, 1.68-12.91).

CONCLUSIONS

Adequate limb oversizing >10% was associated with a significantly decreased risk of TIBEL in limbs with ectatic iliac landing zones. However, no additional benefit was observed for oversizing >10% in limb grafts landing in normal iliac arteries. Furthermore, excessive limb oversizing (>15%) in normal iliac landing zones can be associated with an increased risk of limb occlusion.

Secondary Endoleak Management Following TEVAR and EVAR

Endovascular abdominal and thoracic aortic aneurysm repair and are widely used to treat increasingly complex aneurysms. Secondary endoleaks, defined as those detected more than 30 days after the procedure and after previous negative imaging, remain a challenge for aortic specialists, conferring a need for long-term surveillance and reintervention. Endoleaks are classified on the basis of their anatomic site and aetiology. Type 1 and type 2 endoleaks (EL1 and EL2) are the most common endoleaks necessitating intervention. The management of these requires an understanding of their mechanics, and the risk of sac enlargement and rupture due to increased sac pressure. Endovascular techniques are the main treatment approach to manage secondary endoleaks. However, surgery should be considered where endovascular treatments fail to arrest aneurysm growth. This chapter reviews the aetiology, significance, management strategy and techniques for different endoleak types.

Safety and effectiveness of the TREO stent graft for the endovascular treatment of abdominal aortic aneurysms

OBJECTIVE

The short- and mid-term outcomes of endovascular aortic aneurysm repair have made it a standard treatment of abdominal aortic aneurysms. However, newer generation devices have yet to demonstrate improved long-term rates for complications, reinterventions, and survival. The TREO stent graft is a latest generation device and was evaluated for approval in the United States.

METHODS

In a multicenter, nonrandomized, investigational device exemption clinical trial, we assessed the safety and effectiveness of the TREO device, with core laboratory assessment of the imaging studies and an independent adjudication of safety. The primary effectiveness endpoint was successful aneurysm treatment at 1 year. The primary safety endpoint was the incidence of major adverse events (MAE) at 30 days.

RESULTS

A total of 150 patients (132 men; 88.0%) with infrarenal abdominal aortic (87.3%) or aortoiliac (12.7%) aneurysms were enrolled. The data were normally distributed. The mean age was 71.7 ± 7.4 years. The MAE incidence at 30 days was 0.7%. One subject experienced two MAE: myocardial infarction and procedural blood loss of 1000 mL. The proportion of successful aneurysm treatment at 1 year was 93.1%. Longer term follow-up continues, with no aneurysm-related mortality at the latest follow-up. At 3 years, the cumulative all-cause mortality and incidence of type I and type III endoleaks was 10.7% (n = 16), 2.7% (n = 4), and 0% (n = 0), respectively. In addition, aneurysm sac shrinkage >5 mm at 3 years had occurred in 54.3% of patients, and 9.3% had required a secondary intervention (n = 14).

CONCLUSIONS

The safety and effectiveness of endovascular repair of abdominal aneurysms with TREO were demonstrated, with 93.1% successful aneurysm treatment at 1 year and aneurysm sac shrinkage >5 mm at 3 years in 54.3% of patients. Long-term follow-up continues to determine whether these favorable outcomes will be sustained.

Surveillance Imaging following Endovascular Aneurysm Repair: State of the Art

Endovascular aneurysmal repair (EVAR) has become a prominent modality for the treatment of abdominal aortic aneurysm. Surveillance imaging is important for the detection of device-related complications, which include endoleak, structural abnormalities, and infection. Currently used modalities include ultrasound, X-ray, computed tomography, magnetic resonance imaging, and angiography. Understanding the advantages and drawbacks of each modality, as well available guidelines, can guide selection of the appropriate technique for individual patients. We review complications following EVAR and advances in surveillance imaging modalities.

Risk Factors for Early and Late Type Ib Endoleak Following Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVES

A type Ib endoleak (T1bEL) is a postoperative complication that usually requires additional interventions following endovascular aortic aneurysm repair. Previous studies have focused on iliac artery tortuosity or common iliac artery (CIA) diameter. However, we investigated the various risk factors for early and late T1bELs more comprehensively.

METHODS

This retrospective case-control study of a prospectively maintained database compared anatomical, demographic and technical factors between patients with early or late T1bELs and a control group. Early T1bEL was defined as a T1bEL occurring within 6 months of endovascular aneurysm repair (EVAR), while late T1bEL was defined as a T1bEL, initially identified more than 6 months after EVAR. Anatomical values including neck diameter, length, and angle; maximum sac diameter and length; CIA length, diameter, and tortuosity; and distal sealing length were measured and included in the analysis. We performed uni- and multivariable analyses using logistic regression and Cox proportional hazard models.

RESULTS

This study included 635 iliac limbs of 383 patients. Overall, T1bELs occurred in 22 iliac limbs during the follow-up period (22/635, 3.5%). Among them, the early and late T1bEL groups each included 11 limbs. The median follow-up duration of the 383 patients was 23 (8-58) months, and in the early T1bEL and early control groups, the durations were 15 (9-35) and 29 (15-60) months, respectively (P = 0.01). The median overall follow-up durations in the late T1bEL and late control groups were 87 (76-102) and 62 (48-80) months, respectively (P = 0.01). The median follow-up duration until the occurrence of late T1bEL was 44 (32-82) months, which was shorter than that of the late control group (P = 0.03). No significant differences in sex, age, or brand of stent-graft were observed between the T1bEL and control groups. In the multivariable analysis, patients in the early T1bEL group had significantly more tortuous and short CIAs, and short distal sealing lengths (P = 0.02, P = 0.04, P = 0.03, respectively), and the late T1bEL group had significantly larger maximum aortic aneurysm sac diameters, short CIAs and short distal sealing lengths (P < 0.001, P = 0.02, P = 0.002, respectively). The suspected mechanisms of the T1bELs were CIA dilatation with or without sac expansion and aggravation of sac angulation. Except for one patient with aortic dissection, T1bELs were treated with iliac limb extensions.

CONCLUSIONS

The various mechanisms of T1bELs differed depending on the time of onset from the procedure. An extensive sealing length may be protective against T1bEL, especially when the size of the aortic aneurysm sac is large or when the CIA has risky features, including large diameter or short length. Careful preoperative consideration of aortic aneurysm size and CIA length and tortuosity is essential, and patients with risky features should undergo strict postoperative surveillance.

Aneurysms and dissections - What is new in the literature of 2019/2020 - a European Society of Vascular Medicine annual review

More than 6,000 publications were found in PubMed concerning aneurysms and dissections, including those Epub ahead of print in 2019, printed in 2020. Among those publications 327 were selected and considered of particular interest.

The Use of Iliac Branched Devices in the Acute Endovascular Repair of Ruptured Aortoiliac Aneurysms

BACKGROUND

The objective of this study was to evaluate the feasibility and midterm outcomes of iliac branch devices (IBDs) to preserve the internal iliac artery perfusion in emergent endovascular repair of ruptured aorto-iliac aneurysms.

METHODS

Between December 2012 and July 2017, a total of 8 IBDs were implanted in 6 patients (the median age 65 years; all men) in a single tertiary referral center. The indication for IBD implantation was a ruptured abdominal aortic aneurysm with a concomitant common iliac artery aneurysm (n = 4) or isolated CIA aneurysms (n = 2). The main outcome measures were technical and clinical success. The secondary outcomes were primary and primary assisted patency, the occurrence of type I/III endoleaks, and reinterventions.

RESULTS

All patients were hemodynamically stable during the procedures, which were performed under local anesthesia. Technical success was achieved in all cases (the median total procedure time of 188 min and the median IBD procedure time of 28 min). The median follow-up was 34 months (interquartile range 19-78). There were no deaths during the follow-up and no major complications unrelated to the IBD. Two (25%) secondary interventions were performed for IBD occlusion in patients with bilateral IBDs. The other reintervention was a type II endoleak embolization in 1 of these 2 patients. The freedom from reintervention estimate was 75% through 2 years. The overall primary assisted patency was 100% through 3 years.

CONCLUSIONS

The use of IBDs in the acute setting is feasible to exclude ruptured aortoiliac aneurysms while maintaining pelvic circulation. The secondary intervention rate is considerable; however, the midterm assisted primary patency rates are promising. Further studies are needed to guide patient selection and to evaluate longer term outcomes.