Adequate seal and no endoleak on the first postoperative computed tomography angiography as criteria for no additional imaging up to 5 years after endovascular aneurysm repair

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

OBJECTIVE

This study aimed to assess aneurysm sac dynamics and its prognostic significance following fenestrated and branched endovascular aneurysm repair (F/BEVAR).

METHODS

Patients undergoing F/BEVAR for degenerative complex aortic aneurysm from 2008 to 2020 at two large vascular centres with two imaging examinations (30 day and one year) were included. Patients were categorised as regression and non-regression, determined by the proportional volume change (> 5%) at one year compared with 30 days. All cause mortality and freedom from graft related events were assessed using Kaplan-Meier methods. Factors associated with non-regression at one year and aneurysm sac volume over time were examined for FEVAR and BEVAR independently using multivariable logistic regression and linear mixed effects modelling.

RESULTS

One hundred and sixty-five patients were included: 122 FEVAR, of whom 34% did not regress at one year imaging (20% stable, 14% expansion); and 43 BEVAR, of whom 53% failed to regress (26% stable, 28% expansion). Following F/BEVAR, after risk adjusted analysis, non-regression was associated with higher risk of all cause mortality within five years (hazard ratio [HR] 2.56, 95% confidence interval [CI] 1.09 - 5.37; p = .032) and higher risk of graft related events within five years (HR 2.44, 95% CI 1.10 - 5.26; p = .029). Following multivariable logistic regression, previous aortic repair (odds ratio [OR] 2.56, 95% CI 1.11 - 5.96; p = .029) and larger baseline aneurysm diameter (OR/mm 1.04, 95% CI 1.00 - 1.09; p = .037) were associated with non-regression at one year, whereas smoking history was inversely associated with non-regression (OR 0.21, 95% CI 0.04 - 0.96; p = .045). Overall following FEVAR, aneurysm sac volume decreased significantly up to two years (baseline vs. two year, 267 [95% CI 250 - 285] cm3vs. 223 [95% CI 197 - 248] cm3), remaining unchanged thereafter. Overall following BEVAR, aneurysm sac volume remained stable over time.

CONCLUSION

Like infrarenal EVAR, non-regression at one year imaging is associated with higher five year all cause mortality and graft related events risks after F/BEVAR. Following FEVAR for juxtarenal aortic aneurysm, aneurysm sacs generally displayed regression (66% at one year), whereas after BEVAR for thoraco-abdominal aortic aneurysm, aneurysm sacs displayed a concerning proportion of growth at one year (28%), potentially suggesting a persistent risk of rupture and consequently requiring intensified surveillance following BEVAR. Future studies will have to elucidate how to improve sac regression following complex EVAR, and whether the high expansion risk after BEVAR is due to advanced disease extent.

Individualizing Surveillance after Endovascular Aortic Repair Using a Modular Imaging Algorithm

OBJECTIVES

Surveillance after endovascular aortic repair (EVAR) and fenestrated EVAR (FEVAR) is mainly directed by one-size-fits-all approaches instead of personalized decision making, even though treatment strategies and often endografts themselves are tailor-made to adjust for individual patients. We propose a modular imaging algorithm that escalates surveillance imaging based on invasiveness and need.

MATERIALS AND METHODS

In this retrospective observational study of single-center data, results of a modular imaging algorithm were analyzed. The algorithm is characterized by initiating the examination with standard B-mode then transitioning to Duplex ultrasound, B-Flow, and CEUS. Additional CT(A) studies are conducted where required. The study population included both patients receiving EVAR or FEVAR. A comparative analysis was conducted regarding endoleak detection.

RESULTS

The study population included 28 patients receiving EVAR and 40 patients receiving FEVAR. They accounted for 101 follow-up visits, which led to 431 distinct imaging studies. CEUS has the highest endoleak detection rate, followed by CTA and B-Flow. Duplex ultrasound and B-Flow resulted in 0 and 1 false positive cases, respectively, considering CEUS the reference standard. In a select group of six patients, CEUS was omitted after endoleaks were displayed by Duplex ultrasound or B-Flow, leading to a successful type II coiling and no aneurysm-related adverse events.

CONCLUSIONS

The proposed modular algorithm showed great potential to incorporate principles of personalized medicine in surveillance after endovascular aortic treatment. Since Duplex ultrasound and B-Flow rarely cause false positive endoleaks, more resource-intensive and invasive imaging studies such as CEUS and CTA can be omitted after positive identification.

Geometric Analysis of the Gore Excluder Conformable Endoprosthesis in the Infrarenal Aortic Neck: One Year Results of the EXCeL Registry

OBJECTIVE

The Gore Excluder Conformable Endoprosthesis (CEXC) is designed to treat challenging infrarenal anatomy because of its active angulation control, repositionability, and enhanced conformability. This study evaluated 30 day and one year position and apposition of the CEXC in the infrarenal neck.

METHODS

Patients treated with the CEXC between 2018 and 2022 with an available 30 day computed tomography angiogram (CTA) were selected from four hospitals in a prospective registry. Endograft apposition (shortest apposition length [SAL]) and position (shortest fabric distance [SFD]) were assessed on the 30 day and one year CTAs. Maximum infrarenal aortic curvature was compared between the pre- and post-operative CTAs to evaluate conformability of the CEXC.

RESULTS

There were 87 patients with a 30 day CTA, and for 56 of these patients the one year CTA was available. Median (interquartile range [IQR]) pre-operative neck length was 22 mm (IQR 15, 32) and infrarenal angulation was 52° (IQR 31, 72). Median SAL was 21.2 mm (IQR 14.0, 29.3) at 30 days for all included patients. The SAL in 13 patients (15%) was < 10 mm at 30 days, and one patient had a SAL of 0 mm and a type Ia endoleak. There was no significant difference in SAL between patients within and outside instructions for use. The SAL significantly increased by 1.1 mm (IQR -2.3, 4.7; p = .042) at one year. The SAL decreased in seven patients (13%), increased in 13 patients (23%), and remained stable in 36 patients (64%). Median SFD was 2.0 mm (IQR 0.5, 3.6) at 30 days, which slightly increased by 0.3 mm (IQR -0.5, 1.8; p = .019) at one year. One patient showed migration (SFD increase ≥ 5 mm). Median endograft tilt was 15.8° (IQR 9.7, 21.4). Pre-operative maximum infrarenal curvature was 36 m-1 (IQR 26, 56) and did not significantly change thereafter.

CONCLUSION

In most patients, the CEXC was implanted close to the renal arteries, and sufficient (≥ 10 mm) post-operative apposition was achieved at 30 days, which slightly increased at one year. Post-operative endograft tilt was relatively low, and aortic geometry remained unchanged after implantation of the CEXC, probably due to its high conformability.

Shortest Apposition Length at the First Postoperative Computed Tomography Angiography Identifies Patients at Risk for Developing a Late Type Ia Endoleak After Endovascular Aneurysm Repair

PURPOSE

Imaging surveillance following endovascular aneurysm repair (EVAR) is strictly recommended. This study investigates the value of endograft apposition and position relative to the aortic neck on the first postoperative computed tomography angiography (CTA) in determining patients at risk for a late type Ia endoleak (T1aEL).

MATERIALS AND METHODS

Patients with a T1aEL after the first postoperative CTA were selected from a consecutive database and matched with uncomplicated controls. Endograft apposition and position, including the shortest apposition length (SAL), were determined on the first postoperative CTA. The SAL is the shortest distance between the proximal endograft fabric and the first slice where circumferential apposition with the aortic wall is lost. Differences in endograft apposition at the first postoperative CTA were compared between groups. Logistic regression analysis identified independent predictors for late T1aEL.

RESULTS

A total of 32 patients with a late T1aEL were included and matched with 32 uncomplicated controls. Median follow-up after primary EVAR was 62.0 (interquartile range [IQR]: 36.8, 83.5) months in the T1aEL group compared with 47.5 (IQR: 34.0, 79.3) months in the control group; p=0.265. Median preoperative neck diameter was significantly larger in the T1aEL group than in the control group (26.6 [IQR: 24.9, 29.6] mm versus 23.4 [IQR: 22.5, 25.3] mm); p<0.001. Patients in the T1aEL group had a median SAL of 11.6 (IQR: 4.3, 20.5) mm compared with 20.7 (IQR: 13.1, 24.9) mm in the control group; p=0.002. SAL <10mm on the first postoperative CTA (odds ratio [OR]: 9.63, 95% confidence interval [CI]: 1.60-57.99) and larger neck diameter (OR: 1.80, 95% CI: 1.26-2.57) were independent predictors for developing a late T1aEL.

CONCLUSION

Preoperative neck diameter and SAL on the first postoperative CTA following EVAR are important predictors for the development of a late T1aEL. Patients with a SAL of <10mm had a significantly higher risk of developing a late T1aEL. Future research should determine whether these patients would benefit from reintervention before an actual T1aEL is present.

CLINICAL IMPACT

Understanding the mechanisms of endovascular aneurysm repair failure is essential to further enhance clinical outcomes. Adequate proximal sealing is necessary to foster freedom from type 1a endoleak. This study demonstrates that the shortest apposition length (SAL) at the first postoperative computed tomography angiography (CTA) is able to identify patients at risk for a late type 1a endoleak. Especially patients with a SAL <10mm are at high risk. Currently, the guidelines advice repeated imaging with CTA in patients with a seal <10mm. Future research should determine whether these patients would benefit from re-intervention before an actual type 1a endoleak is present.

One-year aneurysm-sac dynamics are associated with reinterventions and rupture following infrarenal endovascular aneurysm repair

OBJECTIVE

One-year aneurysm sac changes have previously been found to be associated with mortality and may have the potential to guide personalized follow-up following endovascular aneurysm repair (EVAR). In this study, we examined the association of these early sac changes with long-term reintervention and rupture.

METHODS

We identified all patients undergoing first-time EVAR for intact abdominal aortic aneurysm between 2003 and 2018 in the Vascular Quality Initiative with linkage to Medicare claims for long-term outcomes. We included patients with an imaging study at 1 year postoperatively. Aneurysm sac behavior was defined as per the Society for Vascular Surgery guidelines: stable sac (<5 mm change), sac regression (≥5 mm), and sac expansion (≥5 mm). Outcomes included mortality, reintervention, and rupture within 8 years, which were assessed with Kaplan-Meier methods and multivariable Cox regression analysis. Secondarily, we utilized polynomial spline interpolation to demonstrate the continuous relationship of diameter change to 8-year hazard of reintervention, rupture, or mortality as a composite outcome.

RESULTS

Of 31,185 EVAR patients, 16,102 (52%) had an imaging study at 1 year and were included in this study. At 1 year, 44% of sacs remained stable, 49% regressed, and 6.2% displayed expansion. Following risk adjustment, compared with a stable sac at 1 year, sac regression was associated with lower 8-year mortality (49% vs 53%; hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.85-0.99; P = .036), reintervention rate (8.9% vs 15%; HR, 0.58; 95% CI, 0.50-0.68; P < .001), and rupture rate (2.0% vs 4.0%; HR, 0.45; 95%CI, 0.29-0.69; P < .001). Conversely, compared with a stable sac, sac expansion was associated with higher 8-year mortality (64% vs 53%; HR, 1.31; 95% CI, 1.14-1.51; P < .001) and reintervention rate (27% vs 15%; HR, 1.98; 95% CI, 1.57-2.51; P < .001), but similar risk of rupture (7.2% vs 4.0%; HR, 1.61; 95% CI, 0.88-2.96; P = .12). Polynomial spline interpolation demonstrated that, compared with no diameter change at 1 year, increased sac regression was associated with an incrementally lower risk of late outcomes, whereas increased sac expansion was associated with an incrementally higher risk of late outcomes.

CONCLUSIONS

Following EVAR, compared with a stable sac at 1-year imaging, sac regression and expansion are associated with a lower and higher risk respectively of long-term mortality, reinterventions, and ruptures. Moreover, the amount of regression or expansion seems to be incrementally associated with these late outcomes, too. Future studies are needed to determine how to improve 1-year sac regression, and whether it is safe to extend follow-up intervals for patients with regressing sacs.

Midterm Outcomes and Aneurysm Sac Dynamics Following Fenestrated Endovascular Aneurysm Repair after Previous Endovascular Aneurysm Repair

OBJECTIVE

Fenestrated endovascular aneurysm repair (FEVAR) is a feasible option for aortic repair after endovascular aneurysm repair (EVAR), due to improved peri-operative outcomes compared with open conversion. However, little is known regarding the durability of FEVAR as a treatment for failed EVAR. Since aneurysm sac evolution is an important marker for success after aneurysm repair, the aim of the study was to examine midterm outcomes and aneurysm sac dynamics of FEVAR after prior EVAR.

METHODS

Patients undergoing FEVAR for complex abdominal aortic aneurysms from 2008 to 2021 at two hospitals in The Netherlands were included. Patients were categorised into primary FEVAR and FEVAR after EVAR. Outcomes included five year mortality rate, one year aneurysm sac dynamics (regression, stable, expansion), sac dynamics over time, and five year aortic related procedures. Analyses were done using Kaplan-Meier methods, multivariable Cox regression analysis, chi square tests, and linear mixed effect models.

RESULTS

One hundred and ninety-six patients with FEVAR were identified, of whom 27% (n = 53) had had a prior EVAR. Patients with prior EVAR were significantly older (78 ± 6.7 years vs. 73 ± 5.9 years, p < .001). There were no significant differences in mortality rate. FEVAR after EVAR was associated with a higher risk of aortic related procedures within five years (hazard ratio [HR] 2.6; 95% confidence interval [CI] 1.1 - 6.5, p = .037). Sac dynamics were assessed in 154 patients with available imaging. Patients with a prior EVAR showed lower rates of sac regression and higher rates of sac expansion at one year compared with primary FEVAR (sac expansion 48%, n = 21/44, vs. 8%, n = 9/110, p < .001). Sac dynamics over time showed similar results, sac growth for FEVAR after EVAR, and sac shrinkage for primary FEVAR (p < .001).

CONCLUSION

There were high rates of sac expansion and a need for more secondary procedures in FEVAR after EVAR than primary FEVAR patients, although this did not affect midterm survival. Future studies will have to assess whether FEVAR after EVAR is a valid intervention, and the underlying process that drives aneurysm sac growth following successful FEVAR after EVAR.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Five-year outcomes of endosuture aneurysm repair in patients with short neck abdominal aortic aneurysm from the ANCHOR registry

OBJECTIVE

Hostile aortic neck anatomies such as proximal short necks are known to put patients at an increased risk for type IA endoleaks, migration, and need for reinterventions. The Heli-FX EndoAnchor System was designed to improve seal of aortic stent grafts. Endosuture aneurysm repair (ESAR) using EndoAnchors with the Endurant stent graft has been shown to be safe and effective for the treatment of patients with short necks through one year. This study reports the 5-year patient outcomes of the Aneurysm Treatment using the Heli-FX EndoAnchor System Global Registry (ANCHOR) short neck regulatory cohort.

METHODS

The 70 patients from the ANCHOR Registry were cohort submitted to regulators for approval of the Endurant short neck indication. Patients had an infrarenal neck length of ≥ 4 mm and <10 mm. At 5 years, this short neck cohort had clinical and imaging follow-up compliance rates of 85% (28/33) and 70% (23/33), respectively.

RESULTS

The short neck cohort had a mean age of 71.3±8.1 years and was 27.1% (19/70) female. Kaplan Meier freedom from all-cause mortality was 68.5 ± 6.2%, freedom from aneurysm-related mortality was 90.1 ± 4.5%, freedom from any endovascular or surgical secondary procedure was 76.9 ± 7.2%, and freedom from rupture was 95.6 ± 3.2%. Eight patients had a total of nine type IA endoleaks detected through 5 years, of which three resolved spontaneously by the next follow-up visit. There were two patients with renal complications who did not undergo reintervention and there were no device migrations reported through 5 years. After 5 years, 68.2% of patients (15/22) had sac regression, 13.6% (3/22) had stable sacs, and 18.2% (4/22) had increased sac diameter as compared with their 1-month measurements.

CONCLUSIONS

After ESAR treatment using Heli-FX EndoAnchors with Endurant, the 5-year outcomes of the short neck cohort from the ANCHOR registry had encouraging results with regards to proximal neck-related complications, secondary procedures, and sac regression. This review of ESAR in patients with short proximal necks showed positive outcomes through 5 years although follow-up of a larger cohort is necessary.

Possible implications of device-specific variability in post-endovascular aneurysm repair sac regression and endoleaks for surveillance categorization

OBJECTIVE

Significant sac regression during early surveillance has been shown to best predict reintervention-free long-term surveillance after endovascular aneurysm repair (EVAR). Furthermore, a persistent endoleak has been related to a worse outcome. Individualized surveillance algorithms based on these findings have been suggested. There are no studies comparing the performance of different stent grafts regarding sac regression, the presence of type II endoleaks, and their possible implications for individualized surveillance. The objective of this study was to evaluate device-specific differences and how these may affect patient categorization for surveillance.

METHODS

Patients were treated electively with standard EVAR between 2005 and 2015 using three different devices (Zenith by Cook, Excluder by Gore, and Endurant by Medtronic). The data were reviewed retrospectively until 2020. Patients' computed tomography angiographies (CTAs) at 30 days and at 2 years were analyzed for freedom from endoleaks and for sac regression of ≥5 mm. Reinterventions during long-term surveillance were counted. Patients were categorized according to the presence of any endoleak and sac regression at 30 days and 2 years, and the probability of reintervention-free long-term surveillance was evaluated based on these findings.

RESULTS

A total of 435 patients were treated for an abdominal aortic aneurysm with EVAR during the study period. At 30 days, 80.0% (n = 339) of the patients were free from endoleaks, and at 2 years, 78.9% (n = 273) were free from endoleaks. There was a significant difference in endoleak rate at 30 days and 2 years between the devices (P < .001 and P = .001). There was no significant difference in sac regression between the devices at 2 years (P = .096). The categorization at 30 days based on endoleak status had a sensitivity of 44.9%, specificity of 87.4%, and negative predictive value of 84.1% for finding a reintervention-requiring complication during long-term follow-up. The corresponding figures at 2 years were 63.3%, 91.4%, and 89.4%, respectively. The combination of freedom from endoleaks and sac regression of ≥5 mm in the 2-year CTA best predicted an uneventful long-term surveillance. Patients who met this criterion had a 95.6% probability (negative predictive value) of having a reintervention-free long-term surveillance.

CONCLUSIONS

There are significant differences in the prevalence of endoleaks between devices at 30 days and 2 years, but there is no difference in sac regression. Patients with sac regression of ≥5 mm and no endoleaks in the 2-year CTA can be safely categorized for infrequent surveillance regardless of the stent graft model that has initially been used.

Diminishing Endograft Apposition during Follow-Up Is an Important Indicator of Late Type 1a Endoleak after Endovascular Aneurysm Repair

Late type 1a endoleaks (T1aELs) after endovascular aneurysm repair (EVAR) are hazardous complications which should be avoided. This study investigated the evolution of the shortest apposition length (SAL) post-EVAR and hypothesised that a declining apposition during follow-up may be an indicator of T1aEL development. Patients with a late T1aEL were selected from a consecutive multicentre database. For each T1aEL patient, the preoperative computed tomography angiography (CTA), first postoperative CTA, and pre-endoleak CTA were analysed. T1aEL patients were matched 1:1 to uncomplicated controls, based on endograft type and follow-up duration. Anatomical characteristics and endograft dimensions, including the post-EVAR SAL, were measured. Included were 28 patients with a late T1aEL and 28 matched controls. The SAL decreased from 11.2 mm (5.6-20.6 mm) to 3.9 mm (0.0-11.4 mm) in the T1aEL group (p = 0.006), whereas an increase in SAL was seen in the control group from 21.3 mm (14.1-25.8 mm) to 25.4 mm (19.0-36.2 mm; p = 0.015). On the pre-endoleak CTA, 18 patients (64%) in the T1aEL group had a SAL < 10 mm, and one (4%) patient in the control group had a SAL < 10 mm on the matched CTAs. Moreover, three mechanisms of decreasing sealing zone were identified, which might be used to determine optimal imaging or reintervention strategies. Diminishing SAL < 10 mm is an indicator for T1aEL during follow-up, it is imperative to include apposition analysis during follow-up.

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.

Contrast enhanced duplex ultrasound for early postoperative follow-up after endovascular aneurysm repair: Relation to patient's initial risk of complications

OBJECTIVES

Current guidelines recommend initial postoperative follow-up with computed tomography angiography (CTA) after endovascular aneurysm repair (EVAR). However, CTA has risks associated with ionizing radiations and nephrotoxic contrast agents. We investigated possibilities to replace the initial postoperative CTA with contrast enhanced duplex ultrasound (CE-DUS) in selected patients.

METHODS

Out of the 273 consecutive patients who underwent EVAR, 173 were excluded and the 100 patients who underwent CTA and CE-DUS imaging concurrently (≤1 month interval between CTA and CE-DUS imaging) within 60 days after EVAR were analyzed. Patients who underwent EVAR outside the manufacturer's instructions for use or who had endoleaks discovered on intraoperative angiography were classified as the high-risk group, otherwise, they were classified as the low-risk group. Measurements of diagnostic values of CE-DUS ​​related to the detection of complications were calculated using CTA as the gold standard. McNemar's test was performed to compare these values and Pearson correlation coefficient was derived to compare CE-DUS measurements of sac diameters with CTA.

RESULTS

In the low-risk group, no difference was observed between CE-DUS and CTA in the detection of EVAR-related complications (sensitivity = 0.95, specificity = 0.93). In the high-risk group, CE-DUS was not as accurate as CTA for the detection of overall EVAR-related complications (sensitivity = 0.57, specificity = 0.86, p = 0.04) and for the detection of complications other than endoleaks (p = 0.02). Regarding sac diameter measurement, there was good agreement between CE-DUS and CTA (r = 0.92, p < 0.001).

CONCLUSIONS

First postoperative CE-DUS was reliable for the evaluation of EVAR-related complications compared to CTA in selected patients. Individualized EVAR follow-up strategy using CE-DUS based on the initial risk of EVAR-related complications should be considered.

European Expert Opinion on Infrarenal Sealing Zone Definition and Management in Endovascular Aortic Repair Patients: A Delphi Consensus

PURPOSE

The purpose of the study was to provide a consensus definition of the infrarenal sealing zone and develop an algorithm to determine when and if adjunctive procedure(s) or reintervention should be considered in managing patients undergoing endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysm (AAA).

METHODS

A European Advisory Board (AB), made up of 11 vascular surgeons with expertise in EVAR for AAA, was assembled to share their opinion regarding the definition of preoperative and postoperative infrarenal sealing zone. Information on their current clinical practice and level of agreement on proposed reintervention paths was used to develop an algorithm. The process included 2 virtual meetings and 2 rounds of online surveys completed by the AB (Delphi method). Consensus was defined as reached when ≥ 8 of 11 (73%) respondents agreed or were neutral.

RESULTS

The AB reached complete consensus on definitions and measurement of the pre-EVAR target anticipated sealing zone (TASZ) and the post-EVAR real achieved sealing zone (RASZ), namely, the shortest length between the proximal and distal reference points as defined by the AB, in case of patients with challenging anatomies. Also, agreement was achieved on a list of 4 anatomic parameters and 3 prosthesis-/procedure-related parameters, considered to have the most significant impact on preoperative and postoperative sealing zones. Furthermore, the agreement was reached that in the presence of visible neck-related complications, both adjunctive procedure(s) and reintervention should be contemplated (100% consensus). In addition, adjunctive procedure(s) or reintervention can be considered in the following cases (% consensus): insufficient sealing zone on completion imaging (91%) or on the first postoperative computed tomography (CT) scan (91%), suboptimal sealing zone on completion imaging (73%) or postoperative CT scan (82%), and negative evolution of the actual sealing zone over time (91%), even in the absence of visible complications.

CONCLUSIONS

AB members agreed on definitions of the pre- and post-EVAR infrarenal sealing zone, as well as factors of influence. Furthermore, a clinical decision algorithm was proposed to determine the timing and necessity of adjunctive procedure(s) and reinterventions.

Editor's Choice - Post-operative Surveillance and Long Term Outcome after Endovascular Aortic Aneurysm Repair in Patients with an Initial Post-operative Computed Tomography Angiogram Without Abnormalities: the Multicentre Retrospective ODYSSEUS Study

OBJECTIVE

Lifelong imaging surveillance is recommended following endovascular aneurysm repair (EVAR). This study aimed to examine the association between adherence to post-operative surveillance and survival and secondary interventions in patients with an initial post-operative computed tomography angiogram (CTA) without abnormalities.

METHODS

All consecutive patients undergoing EVAR for intact abdominal aortic aneurysm (AAA) in 16 hospitals between 2007 and 2012 were identified retrospectively, with follow up until December 2018. Patients were included if the initial post-operative CTA showed no types I - III endoleak, kinking, infection, or limb occlusion. Discontinued follow up was defined as at least one 16 month period in which no imaging surveillance was performed. Primary outcomes were aneurysm related mortality and secondary interventions, and secondary outcome all cause mortality. Kaplan-Meier analysis was used to estimate survival, and Cox regression analyses to identify the association between independent variables and outcome. Sensitivity analyses were performed by varying the definition of continued yearly follow up. The study protocol was published (bmjopen-2019-033584).

RESULTS

1 596 patients (552 continued, 1 044 discontinued follow up) were included with a median (interquartile range) follow up of 89.1 months (52.6). Cumulative aneurysm related, overall, and intervention free survival was 99.4/94.8/96.1%, 98.5/72.9/85.9%, and 96.3/45.4/71.1% at 1, 5, and 10 years, respectively. American Society of Anesthesiologists (ASA) classification (ASA IV hazard ratio [HR] 3.810, 95% confidence interval [CI] 1.296 - 11.198), increase in AAA diameter (HR 3.299, 95% CI 1.408 - 7.729), and continued follow up (HR 3.611, 95% CI 1.780 - 7.323) were independently associated with aneurysm related mortality. The same variables and age (HR 1.063 per year, 95% CI 1.052 - 1.074) were significantly associated with all cause mortality. No difference in secondary interventions was observed between patients with continued vs. discontinued follow up (89/552; 16% vs. 136/1044; 13%; p = .091). Sensitivity analyses showed worse aneurysm related and overall survival in patients with continued follow up.

CONCLUSION

Discontinued follow up is not associated with poor outcomes. Future prospective studies are indicated to determine in which patients imaging follow up can be safely reduced.

Proximal Seal Dilatation following Fenestrated Endovascular Repair for Complex Abdominal Aortic Aneurysms

OBJECTIVES

Although Proximal neck dilatation following infrarenal endovascular aneurysm repair (EVAR) is common and is associated with proximal graft failure, little is known about sealing zone dilatation and its clinical relevance following fenestrated EVAR (FEVAR). We studied proximal seal dilatation (PSD) dynamics following FEVAR and assessed its clinical significance.

METHODS

We included all consecutive patients treated for a juxta-/supra-renal aneurysm with fenestrated EVAR using the Zenith Fenestrated Endovascular Graft (Cook Medical, Bloomington, Ind) from 2008 to 2018 in two large teaching hospitals in the Netherlands. The primary outcome was PSD over time and was determined using a linear mixed-effects model. Secondary outcomes included associations for early PSD and difference in aortic dilatation at the level of the covered-stent compared to the bare-stent. Proximal seal related adverse events were also obtained.

RESULTS

Our cohort included 84 patients with a median CTA follow-up time of 24.5 months [IQR 17-42]. Maximum aneurysm-diameter was 60.1 mm (IQR 56.9-67.2). Mean proximal seal diameter at baseline was 26.2 mm (±2.8), mean stent oversizing was 20.1% (±9.1), and mean proximal seal length was 29.5 mm (±11.7). Proximal seal dilatation of 1.7 mm (95%CI:1.4-2.1) was found in the first year, decelerating thereafter (2^nd-year: 0.9mm/year [95%CI:0.7-1.1]). Over 10% PSD at one year occurred in 22 patients (27%) and was associated with stent-graft oversizing (OR: 1.1 [95%CI:1.03-1.2], p=.008) and a lower number of target vessels (four fenestrations/ref two fenestrations: OR: 0.13 [95%CI:0.02-0.74], p=.029). At last available imaging, dilatation difference was higher at the level of the covered stent compared with the bare stent (3.0mm [IQR 1.3-5.1] vs. 1.6mm [IQR 0.8-2.5], p<.001). During the study period, only one patient (1.2%) developed a proximal seal related-adverse event (type-IA endoleak).

CONCLUSION

PSD is present following FEVAR, occurring at a faster rate in the first year and subsequently decelerating thereafter, similarly to neck dilatation after standard infrarenal EVAR. Although its clinical implication seems to remain limited in the first years following implantation, further research is required to assess the effect of PSD on long-term FEVAR outcomes.

Hybrid room: Does it offer better accuracy in the proximal deployment of infrarenal aortic endograft?

PURPOSE

This work aims to evaluate the impact of hybrid rooms and their advanced tools on the accuracy of proximal deployment of infrarenal bifurcated endograft (EVAR).

METHODS

A retrospective single centre analysis was conducted between January 2015 and March 2019 including consecutive patients that underwent EVAR. Groups were defined whether the procedure was performed in a hybrid operating room (HOR group) or using a mobile 2D fluoroscopic imaging system (non-HOR group). The accuracy of the proximal deployment was estimated by the distance (mm) between the bottom of the lowest renal artery (LwRA) origin and the endograft radiopaque markers parallax (LwRA/EDG distance) after curvilinear reconstruction. The impact of HOR on the LwRA/EDG distance was investigated using a multiple linear regression model. A composite "proximal neck"-related complications event was studied (Cox models).

RESULTS

Overall, 93 patients (87 %male, median age 73 years) were included with 49 in the HOR group and 44 in the non-HOR group. Preoperative CTA analysis of the proximal neck exhibited similar median length, but different median aortic diameter (p=0.012) and median beta angulation (p=0.027) between groups. The median LwRA/EDG distance was shorter in the HOR group (multivariate model, p=0.022). No difference in "proximal neck"-related complications was evidenced between the HOR and non-HOR groups (univariate analysis, p=0.620). Median follow-up time was respectively 25 [14-28] and 36 months [23-44] in the HOR group and in the non-HOR group (p<0.001).

CONCLUSION

HOR offer more accurate proximal deployment of infrarenal endografts, with however no difference in "proximal neck"-related complications between groups.

Safety and Validity of the Proposed European Society for Vascular Surgery Infrarenal Endovascular Aneurysm Repair Surveillance Protocol: A Single Centre Evaluation

OBJECTIVE

Long term surveillance after endovascular aneurysm repair (EVAR) is essential to detect late complications, but there is variation in practice. The European Society for Vascular Surgery (ESVS) made a recommendation for a new surveillance protocol; one element involves risk stratifying patients depending on sac size reduction and presence of endoleak at their 30 day computed tomography angiogram into low risk groups (delayed imaging to five years) or higher risk groups (continue with the current protocol). The aim was to test this suggested protocol retrospectively within an EVAR patient cohort.

METHODS

Data on EVARs performed from October 2009 to October 2019 were collected. Information gathered from an existing surveillance programme was used to assess the proposed ESVS protocol. All patients who underwent re-intervention were reviewed to see whether adopting the proposed ESVS protocol would have detected these events.

RESULTS

In total, 309 procedures were included. Altogether, 219 of these patients had no endoleak (70.9%) and 86 had a type II (27.8%) endoleak. Only four developed a type I or III endoleak. No patient in the low risk cohort (no initial endoleak or sac shrinkage > 1 cm) required secondary intervention. Five year follow up data were available for 103 patients. In the type II endoleak group, there were 28 secondary interventions in 22 patients. No patient experienced a ruptured aneurysm within five years post-operatively. Had the proposed ESVS protocol been followed, all patients requiring a secondary intervention or with increasing sac size would have been detected/captured. Further, adherence to the ESVS guidelines would have resulted in 103 patients with a five year follow up history qualifying for reduced surveillance. A further 120 patients who had reached the three and four year follow up timepoints could have qualified for a reduced surveillance, reducing imaging cost further.

CONCLUSION

Adopting the proposed ESVS EVAR surveillance protocol safely identified "low risk" patients who did not go on to require a secondary intervention. These patients could benefit from reduced surveillance scanning.

Impact of proximal neck anatomy on short-term and mid-term outcomes after treatment of abdominal aortic aneurysms with new-generation low-profile endografts. Results from the multicentric "ITAlian north-east registry of ENDOvascular aortic repair with the BOltOn Treo endograft (ITA-ENDOBOOT)"

INTRODUCTION

The aim of the study was to evaluate the short-term and mid-term technical and clinical outcomes of the Bolton Treo endograft in subjects with abdominal aortic aneurysm (AAA) requiring endovascular aortic repair (EVAR) and assess if presence of hostile proximal neck would represent a risk factor for increased failure rates.

METHODS

A retrospective review of all consecutive patients who had undergone elective or non-elective EVAR with the Bolton Treo endograft at five institutions located in the North-East of Italy (January 2016-December 2020) was performed. The main exposure variable for this study was presence of hostile (HAN) or friendly (FAN) aortic neck.

RESULTS

A total of 137 consecutive patients were treated with the Bolton Treo endograft at participating institutions; of these 63 (46%) presented HAN while 74 (54%) had FAN. At baseline, no significant differences were observed in the distribution of demographics and comorbidities between study groups. Two type Ia endoleaks (EL) were detected at completion angiography, all in patients with HAN but none in patients with FAN (3% vs 0%, p=.04), but no type III EL were identified in the whole cohort. The median duration of follow-up in the study cohort was 30 months (IQR 22-34 months) and was similar between study groups (p=.87). At three-years, survival estimates were 89% and 91% (p=.82) in patients with HAN and FAN, respectively. At three years, patients with HAN had significantly lower freedom from type IA endoleak as compared with patients with FAN (87% vs 94%, p=.02). No significant differences were found between study groups in the three-year estimates of freedom from reinterventions (80% vs 86%, p=.28). Using cox proportional hazards, presence of type II EL (HR 3.15, 95%CI 1.18-8.5, p=.02) and presence of type IA EL (HR 4.22, 95%CI 1.39-12.85, p=.01) were found as independent predictors for reinterventions in univariate analysis, although they were no longer significant in the multivariate model. Freedom from sac increase >5mm at three years were not significantly different between study groups (92% vs 91%, p=.95).

CONCLUSIONS

Within a contemporary multicentric real-world experience, EVAR with the Bolton Treo endograft shows a satisfactory safety profile in the immediate postoperative phase and acceptable outcomes during mid-term follow-up. Presence of HAN is correlated with development of type Ia EL (either early following stent-graft implantation or late after EVAR) which, in turn, may represent a significant factor leading to reinterventions.

Long-term outcome results after endovascular aortoiliac aneurysm repair with the bifurcated EXCLUDER Endoprosthesis

OBJECTIVE

To report the long-term outcome of patients presenting with an aortic, aortoiliac, or isolated common iliac aneurysm treated with the bifurcated EXCLUDER Endoprosthesis. Furthermore, potential differences in late outcome results between the original- and low-permeability endoprosthesis were analyzed.

METHODS

A retrospective analysis of prospectively collected data of 182 patients who underwent endovascular aneurysm repair with the EXCLUDER Endoprosthesis between June 1998 and October 2015 in an academic, tertiary care center for aortic disease was performed. Patient follow-up was from 3 to 20 years (mean follow-up of 6.9 years). Primary end points were overall survival and reintervention-free survival. Secondary end points were device-related complications, endoleaks, and reinterventions.

RESULTS

Overall survival at 5, 10, and 15 years was 72.8%, 42.1%, and 12.2%, respectively, with no aneurysm-related mortality and no difference in overall survival between the original- vs low-permeability endoprosthesis group (P = .617). Freedom from type I endoleak at 5 years was 94.8%. No new type I endoleak was detected beyond the 5-year follow-up mark. No type III endoleak was identified. Reintervention-free survival was 83.6%, 66.7%, and 66.7% at 5-, 10-, and 15-year follow-up, respectively. There was a significant difference in intervention-free survival between the original- vs low-permeability endoprosthesis group (P = .029) and after the 5-year follow-up mark. In addition, patients with the low-permeability endoprosthesis showed significantly fewer device-related complications (P = .002) and endoleaks (P = .005).

CONCLUSIONS

Endovascular aneurysm repair using the EXCLUDER Endoprosthesis is effective and durable on long-term follow-up, with acceptably low device-related complications and reinterventions. The low-permeability endoprosthesis was associated with significantly fewer new device-related complications and endoleaks after 5 years of follow-up.

Endograft apposition and infrarenal neck enlargement after endovascular aortic aneurysm repair

BACKGROUND

Sufficient apposition and oversizing of the endograft in the aortic neck are both essential for durable endovascular aneurysm repair (EVAR). These measures are however not regularly stated on post-EVAR computed tomography angiography (CTA) scan reports. In this study endograft apposition and neck enlargement (NE) after EVAR with an Endurant II(s) endograft were analyzed and associated with supra- and infrarenal aortic neck morphology.

METHODS

In 97 consecutive elective patients, the aortic neck morphology was measured on the pre-EVAR CTA scan on a 3mensio vascular workstation. The distance between the lowest renal artery and the proximal edge of the fabric (shortest fabric distance, SFD), and the shortest length of circumferential apposition between endograft and aortic wall (shortest apposition length, SAL) was determined on the early post-EVAR CTA scan. NE, defined as the aortic diameter change between pre- and post-EVAR CTA scan, was determined at eight levels: +40, +30, +20, +15, +10, 0, -5 and -10 mm relative to the lowest renal artery baseline. The aortic neck diameter and preoperative oversizing were correlated to NE with the Pearson correlation coefficient. The effective post-EVAR endograft oversizing is calculated from the nominal endograft diameter and the post-EVAR neck diameter where the endograft is circumferentially apposed.

RESULTS

The median time (interquartile range, IQR) between the EVAR procedure and the pre- and post-EVAR CTA scan was 40 (25, 71) days and 36 (30, 46) days, respectively. The Endurant II(s) endograft was deployed with a median (IQR) SFD of 1.0 (0.0, 3.0) mm. The SAL was <10 mm in 9% of patients and significantly influenced by the pre-EVAR aortic neck length (p=0.001), hostile neck shape (p=0.017), and maximum curvature at the suprarenal aorta (p=0.039). The median (interquartile range) SAL was 21.0 (15.0, 27.0) mm with a median (IQR) pre-EVAR infrarenal neck length of 23.5 (13.0, 34.8) mm. The median (IQR) difference between the SAL and neck length was -5.0 (-12.0, 2.8) mm. Significant (p<.001) NE of 1.7 (0.9, 2.5) mm was observed 5 mm below the renal artery baseline, which resulted in an effective post-EVAR endograft oversizing <10% in 43% of the patients. No correlation was found between NE and aortic neck diameter or preoperative oversizing.

CONCLUSIONS

Circumferential apposition between an endograft and the infrarenal aortic neck, SAL, and NE can be derived from standard postoperative CT scans. These variables provide essential information about the post-procedural endograft and aortic neck morphology regardless of the preoperative measurements. Patients with SAL <10 mm or effective oversizing <10% due to NE may benefit from intensified follow-up, but clinical consequences of SAL and NE should be evaluated in future longitudinal studies with longer term follow-up.

Analysis of Outcomes After Endovascular Abdominal Aortic Aneurysm Repair in Patients With Abnormal Findings on the First Postoperative Computed Tomography Angiography

Purpose:

Lifelong follow-up after endovascular abdominal aortic aneurysm repair (EVAR) is recommended due to a continued risk of complications, especially if the first postoperative imaging shows abnormal findings. We studied the long-term outcomes in patients with abnormalities on the first postoperative computed tomography angiography (CTA) following EVAR.

Materials and Methods:

This is a retrospective study of all consecutive patients who underwent elective EVAR for nonruptured abdominal aortic aneurysm (AAA) between January 2007 and January 2012 in 16 Dutch hospitals with follow-up until December 2018. Patients were included if the first postoperative CTA showed one of the following abnormal findings: endoleak type I–IV, endograft kinking, infection, or limb occlusion. AAA diameter, complications, and secondary interventions during follow-up were registered. Primary endpoint was overall survival, and other endpoints were secondary interventions and intervention-free survival. Kaplan-Meier analyses were used to estimate overall and intervention-free survival. Cox regression analyses were used to identify the association of independent determinants with survival and secondary interventions.

Results:

A total of 502 patients had abnormal findings on the first postoperative CTA after EVAR and had a median follow-up (interquartile range IQR) of 83.0 months (59.0). The estimated overall survival rate at 1, 5, and 10 years was 84.7%, 51.0%, and 30.8%, respectively. Age [hazard ratio (HR) 1.06, 95% confidence interval (CI) 1.05 to 1.10] and American Society of Anesthesiologists (ASA) classification (ASA IV HR 3.20, 95% CI 1.99 to 5.15) were significantly associated with all-cause mortality. Overall, 167 of the 502 patients (33.3%) underwent 238 secondary interventions in total. Fifty-eight patients (12%) underwent an intervention based on a finding on the first postoperative CTA. Overall survival was 38.4% for patients with secondary interventions and 44.5% for patients without (log rank; p=0.166). The intervention-free survival rate at 1, 5, and 10 years was 82.9%, 61.3%, and 45.6%, respectively.

Conclusions:

Patients with abnormalities on the first postoperative CTA after elective EVAR for infrarenal AAA cannot be discharged from regular imaging follow-up due to a high risk of secondary interventions. Patients who had a secondary intervention had similar overall survival as those without secondary interventions.

Simple diameter measurements with ultrasound can be safely used to follow the majority of patients after infrarenal endovascular aneurysm repair

BACKGROUND

The optimal imaging follow-up after infrarenal EVAR is still undefined. The objective was to study the outcome of a personalized follow-up program after infrarenal EVAR based on ultrasound AAA diameter measurements for low-risk patients.

METHODS

All consecutive patients followed-up locally after elective and acute infrarenal EVAR between 2010 and 2015 were retrospectively reviewed. Patients underwent CTA at 1 month post-EVAR whereby the attending surgeon defined the subsequent follow-up. Patients considered at low risk were followed with ultrasound only assessing AAA diameter at 1, 2, 3 and every 5 years postoperatively (group A). Low-risk required a favourable preoperative anatomy especially regarding the aneurysm neck, satisfactory intraoperative result and uneventful 1 month CTA (type 2 endoleaks acceptable). Patients not fulfilling the criteria for group A were followed with yearly 3-phase-CTAs (group B).

RESULTS

222 patients with a AAA median diameter of 58 (54-68) mm were included. 191 were allocated into group A and 31 in group B. Median follow-up time was 36 (24-59) months. Five year primary and primary assisted success was 82 ± 5 % and 93 ± 3 % for group A and 70 ± 13% and 93 ± 5% for group B, respectively (P= 0.042 and P= 0.504, respectively). 16 late aneurysm-related re-interventions were performed in 12 patients (7 in group A and 9 in group B). In group A, 5 re-interventions were rupture-preventing and 2 were symptomatic. All late re-interventions in group B were performed following findings on follow-up imaging. Five-year late re-intervention-free survival was 95 ± 2 % and 84 ± 7 % for groups A and B, respectively (P=0.046). Five-year survival was 80 ± 3 % and 63 ± 10 % for group A and B, respectively (P= 0.024).

CONCLUSIONS

A customized follow-up program after infrarenal EVAR based on ultrasound AAA diameter measurements in low-risk patients seems to be effective in maintaining a very high mid-term clinical success rate.

Early and mid-term outcomes following open surgical conversion after failed endovascular aneurysm repair from the "Italian North-easT RegIstry of surgical Conversion AfTer Evar" (INTRICATE)

OBJECTIVE

To report the early and mid-term outcomes following open surgical conversion (OSC) after failed endovascular aortic repair (EVAR) using data from a multicentric registry.

METHODS

A retrospective study was carried out on consecutive patients undergoing OSC after failed EVAR at eight tertiary vascular units from the same geographic area in the North-East of Italy, from April 2005 to November 2019. Study endpoints included early and follow-up outcomes.

RESULTS

144 consecutive patients were included in the study. Endoleaks were the most common indication for OSC (50.7%), with endograft infection (24.6%) and occlusion (21.9%) being the second most prevalent causes. The overall rate of 30-day all-cause mortality was 13.9% (n=20); 32 patients (22.2%) experienced at least one major complication. Mean length of stay (LoS) was 13 ± 12.7 days. On multivariate logistic regression, age (OR 1.09, 95% CI 1.01-1-19, p= .02), renal clamping time (OR 1.07, 95% CI 1.02-1.13, p= .01), and suprarenal/celiac clamping (OR 6.66, 95% CI 1.81-27.1, p= .005) were identified as independent predictors of peri-operative major complications. Age was the only factor associated with peri-operative mortality at 30 days. Renal clamping time > 25 minutes had sensitivity of 65% and specificity of 70% in predicting the occurring of major adverse events (AUC 0.72; 95% CI 0.61-0.82). At 5 years, estimated survival was significantly lower for patients treated due to aortic rupture/dissection (28%, 95% CI 13-61), compared to patients in whom the indication for treatment was endoleak (54%, 95% CI 40-73), infection (53%, 95% CI 30-94), or thrombosis (82%, 95% CI 62-100; p= .0019). 5-year survival rates were significantly lower in patients who received emergent treatment (28%, 95% CI 14-55) as compared with those who were treated in urgent (67%, 95% CI 48-93) or elective setting (57%, 95% CI 43-76; p= .00026). Subjects who received suprarenal/celiac (54%, 95% CI 36-82) or suprarenal (46%, 95% CI 34-62) aortic cross-clamping had lower survival rates at 5 years than those whose aortic-cross clamp site was infrarenal (76%, 95% CI 59-97; p= .041). Using multivariate Cox Proportional Hazard, older age and emergency setting were independently associate with higher risk for overall 5 years mortality.

CONCLUSIONS

OSC after failed EVAR was associated with relatively high rates of early morbidity and mortality, particularly for emergency setting surgery. Endoleaks with secondary sac expansion were the main indication for OSC and suprarenal aortic cross-clamping was frequently required. Endograft infection and emergent treatment remained associated with poorer short-term and long-term survival.

Risk Factors, Dynamics, and Clinical Consequences of Aortic Neck Dilatation after Standard Endovascular Aneurysm Repair

OBJECTIVE

Aortic neck dilatation (AND) occurs after endovascular aneurysm repair (EVAR) with self expanding stent grafts (SESs). Whether it continues, ultimately exceeding the endograft diameter leading to abdominal aortic aneurysm (AAA) rupture, remains uncertain. Dynamics, risk factors, and clinical relevance of AND were investigated after EVAR with standard SESs.

METHODS

All intact EVAR patients treated from 2000 to 2015 at a tertiary institution were included. Demographic, anatomical, and device related characteristics were investigated as risk factors for AND. Outer to outer diameters were measured at a single standardised aortic level on reconstructed computed tomography (CT) images.

RESULTS

A total of 460 patients were included (median follow up 5.2 years, interquartile range [IQR] 3.0, 7.7 years; CT imaging follow up 3.3 years, IQR 1.3, 5.4). Baseline neck diameter was 24 mm (IQR 22, 26) and increased 11.1% (IQR 1.5%, 21.9%) at last CT imaging. Endograft oversizing was 20.0% (IQR 13.6, 28.0). AND was greater during the first year (5.2% [IQR 0, 11.7]) decreasing subsequently (two to four years to 1.4%/year [IQR 0.0, 4.5%], p ≤ .001) and was associated with suprarenal fixation endografts (t value = 7.9, p < .001) and oversizing (t value = 4.4, p < .001). AND exceeding the endograft was 3.5% (95% CI 2.2% - 4.8%) and 14.4% (95% CI 11.0% - 17.8%) at five and eight years, respectively. Excessive AND was associated with baseline neck diameter (OR 1.2/mm, 95% CI 1.05 - 1.41) while the Excluder endograft had a protective effect (OR 0.15, 95% CI 0.04 - 0.58). Excessive AND was associated with type 1A endoleak (HR 3.3, 95% CI 1.1 - 9.7) and endograft migration > 5 mm (HR 3.1, 95% CI 1.4 - 6.9).

CONCLUSION

AND after EVAR with SES is associated with endograft oversizing and radial force but decelerates after the first post-operative year. Baseline aortic neck diameter and suprarenal stent bearing endografts were associated with an increased risk of AND beyond nominal stent graft diameter. However, it remains unclear whether patient selection, differences in endograft radial force or the suprarenal stent are accountable for this difference.

Aneurysm Volumes After Endovascular Repair of Ruptured vs Intact Aortic Aneurysms: A Retrospective Observational Study

Purpose

To compare changes in abdominal aortic aneurysm (AAA) sac volume between endovascular aneurysm repairs (EVAR) performed for ruptured (rEVAR) vs intact (iEVAR) AAAs and to determine the impact of early volume shrinkage on future complications.

Materials and Methods

A retrospective analysis was performed of all patients undergoing standard infrarenal EVAR from 2002 to 2016 at a tertiary referral institution. Only patients with degenerative AAAs and with 30-day and 1-year computed tomography angiography (CTA) imaging were included. Early sac shrinkage was defined as a volume sac reduction >10% between the first (<30-day) and the 1-year CTA. The primary endpoint was to compare AAA sac volume changes between patients undergoing rEVAR (n=51; mean age 71.0±8.5 years; 46 men) vs iEVAR (n=393; mean age 72.3±7.5 years; 350 men). Results are reported as the mean difference with the interquartile range (IQR Q1, Q3). The secondary endpoint was freedom from aneurysm-related complications after 1 year as determined by regression analysis; the results are presented as the hazard ratio (HR) and 95% confidence interval (CI).

Results

At baseline, the rEVAR group had larger aneurysms (p<0.001) and shorter (p<0.001) and more angulated (p=0.028) necks. Aneurysm sac volume decreased more in the rEVAR group during the first year [−26.3% (IQR −38.8%, −12.5%)] vs the iEVAR group [−11.9% (IQR −27.5%, 0); p<0.001]. However, after the first year, the change in sac volume was similar between the groups [−3.8% (IQR −32.9%, 31.9%) for rEVAR and −1.5% (IQR −20.9%, 13.6%) for iEVAR, p=0.74]. Endoleak occurrence during follow-up was similar between the groups. In the overall population, patients with early sac shrinkage had a lower incidence of complications after the 1-year examination (adjusted HR 0.59, 95% CI 0.39 to 0.89, p=0.01).

Conclusion

EVAR patients treated for rupture have more pronounced aneurysm sac shrinkage compared with iEVAR patients during the first year after EVAR. Patients presenting with early shrinkage are less likely to encounter late complications. These parameters may be considered when tailoring surveillance protocols.

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.

Endoluminal Management of Infra-renal Aortic and Aorto-iliac Aneurysms

This paper reviews the development of endovascular aneurysm repair (EVAR) of infra-renal aortic and iliac artery aneurysms and considers the current status and best treatment options. The vast majority of devices are bifurcated and exclude the aneurysm utilizing the same techniques for fixation and seal. The modern EVAR procedure is usually performed in a hybrid operating theatre, utilizing image fusion and other radiation-reducing techniques and using optimized procedural techniques, including percutaneous access. The best outcomes are achieved in patients whose anatomy is within device "instructions for use", but these are most commonly breached due to "hostile" neck anatomy. Endovascular options for these cases include the use of fenestrated endografts, chimney grafts and endoanchors. Concomitant iliac artery aneurysms often occur with abdominal aortic aneurysms, and endovascular options include limb extensions with internal iliac embolization as well as iliac branch devices. The durability of EVAR has recently been called into question by long-term results from early EVAR randomized trial. Findings such as infra-renal neck dilatation and aneurysm sac expansion are relatively common and associated with adverse outcomes. This durability concern mandates regular and long-term imaging and clinical surveillance. It also indicates that EVAR technology is not fully evolved with a need for further development to improve patient applicability and long-term durability.

Computed Tomography-Aortography Versus Color-Duplex Ultrasound for Surveillance of Endovascular Abdominal Aortic Aneurysm Repair

Background

Color-duplex ultrasonography (DUS) could be an alternative to computed tomography-aortography (CTA) in the lifelong surveillance of patients after endovascular aneurysm repair (EVAR), but there is currently no level 1 evidence. The aim of this study was to assess the diagnostic accuracy of DUS as an alternative to CTA for the follow-up of post-EVAR patients.

Methods

Between December 16, 2010, and June 12, 2015, we conducted a prospective, blinded, diagnostic-accuracy study, in 15 French university hospitals where EVAR was commonly performed. Participants were followed up using both DUS and CTA in a mutually blinded setup until the end of the study or until any major aneurysm-related morphological abnormality requiring reintervention or an amendment to the follow-up policy was revealed by CTA. Database was locked on October 2, 2017. Our main outcome measures were sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratios of DUS against reference standard CTA. CIs are binomial 95% CI.

Results

This study recruited prospectively 659 post-EVAR patients of whom 539 (82%) were eligible for further analysis. Following the baseline inclusion visit, 940 additional follow-up visits were performed in the 539 patients. Major aneurysm-related morphological abnormalities were revealed by CTA in 103 patients (17.2/100 person-years [95% CI, 13.9–20.5]). DUS accurately identified 40 patients where a major aneurysm-related morphological abnormality was present (sensitivity, 39% [95% CI, 29–48]) and 403 of 436 patients with negative CTA (specificity, 92% [95% CI, 90–95]). The negative predictive value and positive predictive value of DUS were 92% (95% CI, 90–95) and 39% (95% CI, 27–50), respectively. The positive likelihood ratio was 4.87 (95% CI, 2.9–9.6). DUS sensitivity reached 73% (95% CI, 51–96) in patients requiring an effective reintervention.

Conclusions

DUS had an overall low sensitivity in the follow-up of patients after EVAR, but its performance improved meaningfully when the subset of patients requiring effective reinterventions was considered.

Registration

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01230203.

Total Luminal Volume Predicts Risk after Endovascular Aneurysm Repair

OBJECTIVE

Large aneurysm diameter represents a well known predictor of late complications after endovascular aneurysm repair (EVAR). However, the role of the thrombus free lumen inside the abdominal aortic aneurysm (AAA) sac is not clear. It was hypothesised that greater luminal volume represents a relevant risk factor for late complications after EVAR.

METHODS

A retrospective cohort analysis was performed including all patients undergoing EVAR from 2005 to 2016 at a tertiary referral institution. Pre-operative AAA lumen volume was measured in centre lumen line reconstructions and patients were stratified into quartiles according to luminal volume. The primary endpoint was freedom from AAA related complications. Secondary endpoints were freedom from neck events (type 1A endoleak, migration >5 mm or any pre-emptive neck related intervention), iliac related events (type 1B endoleak or pre-emptive iliac related intervention), and overall survival.

RESULTS

Four hundred and four patients were included: 101 in the first quartile (Q1; <61 cm³). Patients with higher luminal volumes had wider, shorter, and more angulated proximal necks. There were more ruptured AAAs, more aorto-uni-iliac implanted devices and patients outside neck instructions for use in the 4th quartile. Five year freedom from AAA related complications was 79%, 66%, 58% and 56%, respectively (p = .007). At five years, freedom from neck related events was 86%, 84%, 73%, and 71%, respectively, for the four groups (p = .009), and freedom from iliac related events was 96%, 91%, 88%, and 88%, respectively (p = .335). On multivariable analysis, luminal volume was an independent predictor of late complications (Q4 vs. Q1 - hazard ratio: 1.91, 95% confidence interval 1.01-3.6, p = .046). Overall survival at five years was not affected by lumen volume (p = .75).

CONCLUSION

AAA luminal volume represents an important risk factor for AAA related complications. This information may be considered when deciding tailoring surveillance protocols after EVAR. However, larger studies are needed to validate this hypothesis.

Best Practice Guidelines: Imaging Surveillance After Endovascular Aneurysm Repair

OBJECTIVE. Abdominal aortic aneurysm is a significant cause of morbidity and mortality in the United States. Endovascular aneurysm repair (EVAR) is the preferred treatment modality. Surveillance imaging after EVAR detects potential complications. The most common complication is endoleak, which can predispose the aorta to rupture. This article provides a comprehensive and evidence-based review regarding surveillance imaging after EVAR to help readers understand current societal guidelines, guide institutional protocols, and provide a framework to facilitate safe, cost-effective, and clinically relevant imaging of patients after EVAR. CONCLUSION. Lifelong surveillance is necessary for patients who have undergone EVAR. Triple-phase CT angiography (CTA) within 30 days after EVAR is necessary to triage patients appropriately and guide future imaging. Patients without endoleak on initial CTA can be monitored with annual duplex ultrasound. Patients with type I or type III endoleaks should be referred for intervention. Patients with type II and type V endoleaks should be referred for intervention only if the sac diameter grows by more than 1 cm. MR angiography should be used primarily as a problem-solving modality or in patients with contraindications to contrast media or radiation. Strong consideration should be given to more frequent surveillance in patients who have undergone EVAR who have aneurysms with a hostile neck anatomy compared with those patients with favorable neck anatomy.

Stent-graft surface movement after endovascular aneurysm repair: baseline parameters for prediction, and association with migration and stent-graft-related endoleaks

OBJECTIVES

To evaluate the influence of baseline parameters on the occurrence of stent-graft surface movement after endovascular aneurysm repair (EVAR) and to investigate its association with migration and stent-graft-related endoleaks (srEL).

METHODS

In this retrospective, cross-sectional study, three-dimensional surface models of the stent-graft, delimited by landmarks using custom-built software, were derived from the pre-discharge and last follow-up computed tomography angiography (CTA). Stent-graft surface movement in the proximal anchoring zone between these examinations was considered significant at a threshold of 9 mm. The Cox proportional hazards model was used to determine baseline variables associated with the occurrence of stent-graft surface movement. The association between migration and srEL with stent-graft surface movement was tested with the chi-square and the Fisher exact test, respectively.

RESULTS

Stent-graft surface movement was observed in 54 (28.9%) of 187 patients. Multivariate analysis revealed that age ([HR] 1.05; p = 0.017), proximal neck diameter ([HR] 5.07; p < 0.001), infrarenal aortic neck angulation ([HR] 1.02, p = 0.002), and proximal neck length ([HR] 0.62, p < 0.001) were significantly associated with the occurrence of stent-graft surface movement. Migration and srEL occurred in 17 (31.5%) and 5 (9.3%) patients, with and 11 (8.3%) and 2 (1.5%) without stent-graft surface movement (p < 0.001, p = 0.022).

CONCLUSIONS

Age, neck diameter, infrarenal neck angulation, and proximal neck length were significantly associated with the occurrence of stent-graft surface movement. Apart from possible use of adjunctive sealing systems, concerned patients may benefit from regular CTA surveillance, enabling timely diagnosis of subtle changes of stent-graft position.

KEY POINTS

• Stent-graft surface movement, demonstrating subtle, three-dimensional changes in stent-graft position in the proximal anchoring zone, can be derived from CTA examinations. • Age, proximal neck diameter, and infrarenal neck angulation were significantly associated with an increased incidence of stent-graft surface movement. Stent-graft surface movement is significantly more frequent in patients with stent-graft migration and stent-graft-related endoleaks. • Consideration of risk factors for stent-graft surface movement may help to identify patients who might benefit from regular CTA surveillance and timely diagnosis of subtle changes of stent-graft position, enabling re-interventions to prevent migration and srEL.

Application of Baseline Clinical and Morphological Parameters for Prediction of Late Stent Graft Related Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysm

OBJECTIVES

To evaluate the influence of baseline clinical and morphological parameters on the occurrence of a late stent graft related endoleak (srEL; types 1 and 3) after endovascular aneurysm repair (EVAR).

METHODS

This is a retrospective case control study of patients who were routinely followed up after EVAR of abdominal aortic aneurysms. Pre-interventional, pre-discharge, and last available multislice computed tomography angiogram (MSCTA) of 279 patients were analysed. Stent graft related endoleaks detected by follow up MSCTA at least six months after EVAR were specified as late srEL. Baseline demographic characteristics and morphological variables were derived from the pre-interventional and pre-discharge MSCTA. Univariable and multivariable analysis with a Cox proportional hazards model were used to determine baseline factors associated with the occurrence of a late srEL.

RESULTS

Twenty-four (8.6%) of 279 patients suffered a late srEL, during a mean MSCTA follow up of 30.9 ± 25.8 (23.5, IQR 10.6-42.8) months. In the univariable analysis, age (hazard ratio [HR] 1.09; p = .001), female sex (HR 3.25; p = .014), right iliac sealing diameter (HR 10.04; p = .03), left iliac sealing diameter (HR 8.65; p = .001), infrarenal aortic neck angulation (HR 1.02; p = .011), and suprarenal fixation level (HR 3.47; p = .014) were significantly associated with an increased incidence of late srEL. Age (HR 1.08; p = .012), female sex (HR 2.72; p = .049), and left iliac sealing diameter (HR 4.48; p = .033) proved to be risk factors significantly associated with a higher incidence of late srEL in multivariable analysis.

CONCLUSIONS

Older patients, those with female gender, and those with larger left iliac sealing diameters seem to experience higher rates of late srEL. Independent confirmation of these must be addressed in larger studies.

Explant of aortic stent grafts following endovascular aneurysm repair

Background

Failure of endovascular aneurysm repair may require explant of the stent graft in a subset of patients. We sought to assess outcomes in a cohort of patients undergoing explant of endovascular aneurysm repair in both emergency and elective settings.

Methods

Patients undergoing explant of endovascular aneurysm repair were identified from a prospectively maintained database, with additional information obtained through retrospective analysis of medical records.

Results

Over a 21-year period, 1997–2018 (May), there were 597 endovascular aneurysm repair procedures performed in our institution for abdominal aortic aneurysm. There were 19 endovascular aneurysm repair explants; five of these were referrals from other vascular centres. The median age was 73 years (range 46–81). The median length of time from insertion to explant was 39.2 months (range 0–153). Indications for elective explant were type Ia endoleak (n = 4), type 1b endoleak (n = 1), type II endoleak with increasing sac size (n = 1), type I/III endoleak (n = 1), type IV endoleak (n = 1), and increasing sac size without evident endoleak (type V, n = 2). The remaining nine cases were emergency procedures, with four patients presenting with rupture post endovascular aneurysm repair, four patients presenting with acute stent thrombosis, of which one also had a type 1a endoleak and one aorto-enteric fistula. There were no mortalities in the elective group and three mortalities in the emergency group (0 vs 33.3%, p = 0.087). Overall 30-day mortality was 15.8%

Conclusion

Explant of aortic stent grafts can be associated with high mortality and morbidity rates, especially in the emergent setting. Patient and device selection and post-operative surveillance remain vitally important to optimise outcomes post endovascular aneurysm repair.

Evolution and clinical relevance of common iliac artery seal zone after endovascular aortic aneurysm repair

Objective

Data in literature suggest iliac artery dilatation and endograft retraction as complications after endovascular aneurysm repair. However, mainly older generation endografts were included. Therefore, we sought to evaluate the distal sealing zone chronological changes after endovascular aneurysm repair with newer generation stent-grafts.

Methods

Clinical and radiological data of patients with abdominal aortic aneurysms treated with endovascular aneurysm repair between January 2010 and December 2013 were reviewed. Measurements were made using volumetric reconstructions in the first and last available computed tomography angiography. Endpoints of the study were the presence of iliac dilatation and retraction of the endograft. Association with distal oversizing and sealing length was analyzed.

Results

Consecutive patients with a total of 52 common iliac arteries were included in the study (mean age 74.9 ± 6.8 years, four women (7.7%)). The mean follow-up was 3.1 years. The mean iliac diameter increased from 15.5 to 17.1 mm ( p < .001) in the first control computed tomography angiography and to 18.7 mm ( p < .001) in the last available computed tomography angiography. No endograft (Endurant by Medtronic (24/52; 46%), Excluder de Gore (23/52; 44%), Zenith by Cook (5/52; 9%)) was associated with dilatation ( p = .066) or iliac retraction ( p = .591). Two type Ib endoleaks were found (3.8%) and successfully treated with distal graft extension. An iliac branch retraction of ≥5 mm was identified in seven cases (13%). Iliac arteries treated with limbs of ≥24 mm in diameter dilated significantly more than the rest of limbs (5.37 mm versus 3.12 mm; p = .022). In the last available imaging, iliac dilatation was ≥20% in 28 cases (53.8%) and had exceeded the diameter of the implanted endograft in 20 cases (38.4%). Iliac dilatation (OR 15.11 per mm, p = .025) was identified as a risk factor for retraction ≥5 mm.

Conclusion

Iliac dilatation and endograft limb retraction are common findings after endovascular aneurysm repair despite the use of new generation endografts. Optimizing the iliac sealing length and meticulous computed tomography angiography surveillance are recommended especially in case of use ≥24 mm iliac stent-grafts to prevent possible complications.