Outcomes of endovascular aneurysm repair in patients with hostile neck anatomy

The Anaconda One-LokTM stent graft for the treatment of infrarenal abdominal aortic aneurysms: clinical results, technical, and mechanical characteristics

INTRODUCTION

The Anaconda aortic stent graft is a trimodular endovascular stent graft with an active infrarenal fixation suitable for the treatment of infrarenal abdominal aortic aneurysms with an infrarenal neck angulation ≤90°. A unique magnet-based mechanism facilitates the cannulation of the contralateral leg.

AREAS COVERED

The present article provides a complete description of the third-generation Anaconda endograft, the Anaconda One-LokTM, its clinical performance and the related technical and mechanical characteristics as well as a brief comparison between itself and other similar endografts.

EXPERT OPINION

The Anaconda One-Lok stent graft is particularly suitable for abdominal aortic aneurysms with an infrarenal aortic neck angulation up to 90°. Issues that need to be resolved concern the higher incidence of iliac limb occlusion and distal migration compared to other commercially available endografts and possibly the valley central migration with the risk of covering the renal ostia.

Computational prediction of proximal sealing in endovascular abdominal aortic aneurysm repair with unfavorable necks

BACKGROUND AND OBJECTIVE

Endovascular aortic aneurysm repair (EVAR) has become the standard treatment for abdominal aortic aneurysms in most centers. However, proximal sealing complications leading to endoleaks and migrations sometimes occur, particularly in unfavorable aortic anatomies and are strongly dependent on biomechanical interactions between the aortic wall and the endograft. The objective of the present work is to develop and validate a computational patient-specific model that can accurately predict these complications.

METHODS

Based on pre-operative CT-scans, we developed finite element models of the aorta of 10 patients who underwent endovascular aortic aneurysm repair, 7 with standard morphologies and 3 with unfavorable anatomies. We simulated the deployment of stent grafts in each aorta by solving mechanical equilibrium with a virtual shell method. Eventually we compared the actual stent ring positions from post-operative computed-tomography-scans with the predicted simulated positions.

RESULTS

A successful deployment simulation could be performed for each patient. Relative radial, transverse and longitudinal deviations were 6.3 ± 4.4%, 2.5 ± 0.9 mm and 1.4 ± 1.1 mm, respectively.

CONCLUSIONS

The numerical model predicted accurately stent-graft positions in the aortic neck of 10 patients, even in complex anatomies. This shows the potential of computer simulation to anticipate possible proximal endoleak complications before EVAR interventions.

Predictive Parameters of Type 1A Endoleak for Elective Endovascular Aortic Repair: A Single-Center Experience

BACKGROUND

One of the most important factors that affects the success of Endovascular Aortic Repair (EVAR) treatment is the morphology of the neck of the aneurysm. Today, EVAR can be performed even in patients who do not meet the Instruction For Use criteria with hostile neck risk factors; thanks to the developing experience and technology. Our aim in this study was to determine risk factors for Type 1a endoleaks in patients who underwent EVAR and predictive factors for Type 1a endoleaks in patients with combinations of these risk factors.

METHODS

Patients who underwent elective EVAR for infrarenal abdominal aortic aneurysm in our medical center between July 2016 and January 2021 were enrolled. Of these 244 patients, 180 patients with documented preoperative and postoperative computed tomographic angiography results and a follow-up of at least 1 year were included in the study. The Mann-Whitney U test and Student's t-test were used to assess the relationship between nominal data and numerical values, and the t-test and Wilcoxon test were used to compare dependent groups. Logistic regression analysis was performed to model risk factors associated with endoleaks.

RESULTS

The results showed that a neck length less than 15 mm increased the development of type 1a endoleak by 10.4 times (P < 0.001). Furthermore, a neck diameter more than 28 mm increased the development of type 1a endoleak by 21.9 times (P = 0.04). A conical neck structure (gradual neck dilation > 2 mm) increased the development of type 1a endoleaks 4.8 times (P = 0.04). The presence of calcification (> 150 Hounsfield Unit and > 2 mm) in the neck increased the risk of type 1a endoleaks fourfold (P = 0.04). Hostile neck parameters were analyzed and patients with only 1 parameter (n = 69) had a 7.2% type 1a endoleak rate, while patients with 2 parameters (n = 15) had 26.6% and patients with more than 2 parameters (n = 11) had 45.5% type 1a endoleak rate.

CONCLUSIONS

Morphologic features of the neck structure of the aneurysm are among the most important parameters that affect the success of EVAR treatment. Alternative treatments should be considered in patients with more than 1 unfavorable neck parameter.

Safety and Efficacy of Endovascular Aortic Repair for Abdominal Aortic Aneurysms with a Hostile Neck Anatomy

OBJECTIVE

This study aimed to investigate the safety and efficacy of endovascular aortic repair (EVAR) for the treatment of an abdominal aortic aneurysm (AAA) with a hostile neck anatomy (HNA).

METHODS

From January 1, 2015 to December 31, 2019, a total of 259 patients diagnosed with an AAA who underwent EVAR were recruited into this study. Based on the morphological characteristics of the proximal neck anatomy, the patients were divided into the HNA group and the friendly neck anatomy (FNA) group. The patients were followed up for up to 4 years.

RESULTS

The average follow-up time was 1056.1±535.5 days. Type I endoleak occurred in 4 patients in the HNA group, and 2 patients in the FNA group. Neither death nor intraoperative switch to open repair occurred in either group. The time of the operation was significantly longer in the HNA group (FNA vs. HNA, 99.2±51.1 min vs. 117.5±63.8 min, P=0.011). There were no significant differences in short-term clinical success rate (P=0.228) or midterm clinical success rate (P=0.889) between the two groups. The overall mortality rate was 10.4%, and Kaplan-Meier survival analysis indicated that the two groups had similar cumulative survival rates at the end of the follow-up period (P=0.889).

CONCLUSION

EVAR was feasible and safe in patients with an AAA with a proximal HNA. The early and midterm results were promising; however, further studies are needed to verify the long-term effectiveness of EVAR.

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.

Proximal Instructions for Use Violations in Elective Endovascular Aneurysm Repair in the Vascular Quality Initiative: Retrospective Analysis

BACKGROUND

Endovascular aneurysm repair (EVAR) is often attempted in patients with marginal anatomy. These patients' midterm outcomes are available in the Vascular Quality Initiative for analysis.

STUDY DESIGN

Retrospective analysis of prospectively collected data in the Vascular Quality Initiative from patients who underwent elective infrarenal EVAR between 2011 and 2018. Each EVAR was identified as either on- or off-instructions for use (IFU) based on aortic neck criteria. Multivariable logistic regression models were used to assess associations between aneurysm sac enlargement, reintervention, and type Ia endoleak with IFU status. Kaplan-Meier time-to-event models estimated reintervention, aneurysm sac enlargement, and overall survival.

RESULTS

We identified 5,488 patients with at least 1 follow-up recorded. Those treated off-IFU included 1,236 patients ([23%] mean follow-up 401 days) compared with 4,252 (77%) treated on-IFU (mean follow-up 406 days). There was no evidence of significant differences in crude 30-day survival (96% vs 97%; p = 0.28) or estimated 2-year survival (97% vs 97%; log-rank p = 0.28). Crude type Ia endoleak frequency was greater in patients treated off IFU (2% vs 1%; p = 0.03). Off-IFU EVAR was associated with type Ia endoleak on multivariable regression model (odds ratio 1.84 [95% CI 1.23 to 2.76]; p = 0.003). Patients treated off IFU vs on IFU experienced had increased risk of reintervention within 2 years (7% vs 5%; log-rank p = 0.02), a finding consistent with results from the Cox modeling (hazard ratio 1.38 [95% CI 1.06 to 1.81]; p = 0.02).

CONCLUSIONS

Patients treated off IFU were at greater risk for type Ia endoleak and reintervention, although they had similar 2-year survival compared with those treated on IFU. Patients with anatomy outside IFU should be considered for open surgery or complex endovascular repair to reduce the probability for revision.

The effect of stent graft curvature on the hemodynamic displacement force after abdominal aortic aneurysm endovascular repair

Endovascular aortic aneurysm repair is a minimally invasive procedure with low mortality and morbidity. Clinical studies have revealed that a displacement force (DF) can cause stent graft (SG) migration in some circumstances requiring repeated intervention. This study aims to determine the relationship between the SG curvature and the calculated DF from four patient-specific computational fluid dynamics models. The SG's curvature was defined according to the centrelines of the implanted SG's branches. The centrelines were defined as either intersecting or separated lines. The centreline curvature (CLC) metrics were calculated based on the local curvature radii and the distances from the centrelines of idealized straight branches. The average CLC value and average variation were calculated to represent the entire graft's curvature. These CLC calculations were compared, and the method that gave the best correlation to the calculated DF was found. The optimal correlation is obtained from calculating the CLC average variation using separated centrelines and distance from straight lines, with an R2 = 0.89. Understanding the relationship between vascular morphology and DF can help identify at-risk patients before the procedure. In these cases, we can provide appropriate treatment and follow up with the patient to prevent future failure.

Aligning Orifice of the Renal Artery with Fish-Mouth FIXation Technique During Endovascular Aortic Aneurysm Repair for Hostile Neck Anatomy

Background: As the success of endovascular aortic aneurysm repair (EVAR) depends on sufficient proximal fixation of the endograft to the aortic wall, the proximal hostile neck anatomy (HNA) is the major potential treatment-limiting factor in EVAR. The Aorfix endovascular stent graft was designed to operate on highly angulated aortic necks. The Aligning Orifice of the Renal artery with fish-mouth FIXation (AORFIX) technique uniquely and accurately aligns the trough part of the proximal stent end with the orifice of the lower renal artery and is used to optimize the proximal fish-mouth design for maximum proximal seal use. Herein, we aimed to evaluate the usefulness of the AORFIX technique for EVAR in patients with HNA. Methods: Eighty-one consecutive patients who underwent EVAR with the AORFIX technique (+AORFIX technique group, n = 16) and without (standard group, n = 65) were evaluated. The HNA was defined as any of the following: neck angulation ≥60°, neck length ≤15 mm, or neck thrombus or calcification ≥50% of the circumference and conical neck. Results: Each HNA criterion was similar between the two groups. However, the average number of HNA criteria was significantly higher in the +AORFIX technique group (1.9 ± .2 vs. 1.3 ± .1; P < .01). The two groups showed 100% procedural success. The concurrent renal angioplasty and stenting rates (88% vs. 4.6%; P < .01) were significantly higher in the +AORFIX technique group. There were no 30-day deaths in either group and no in-hospital device-related events in the +AORFIX technique group. The median follow-up period was 39 months, and there was no significant between-group difference in freedom from reintervention rate (+AORFIX group vs. standard group, 100% vs. 91.0%; P = .327). Conclusion: EVAR using the AORFIX technique might be useful even in patients with more complex HNA.

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

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

Open Abdominal Aortic Aneurysm Surgery and Renal Dysfunction; Association of Demographic and Clinical Variables with Proximal Clamp Location

BACKGROUND

While cross-clamp site is a known risk factor for postoperative acute and chronic renal dysfunction following open abdominal aortic aneurysm surgery (AAA), the additive impact of patient demographic and clinical factors is lacking. In this study, we investigated the impact of body mass index (BMI), surgical duration and aneurysm diameter on the association between proximal cross-clamp location and postoperative renal dysfunction.

METHODS

In this study, we conducted a retrospective analysis of 4,197 patients undergoing open AAA surgery between 2011 and 2018 using data housed in the American College of Surgeons National Safety Quality Improvement Program (ACS-NSQIP) database. The primary outcome was renal dysfunction, which was defined as patients requiring dialysis within 30 days or patients with ≥2 mg/dL rise in creatinine from baseline. We assessed the incidence of renal dysfunction with regard to clamp location and subsequently used multivariable logistic regression to assess clinical and demographic factors associated with renal dysfunction. We used a regression model to plot the association of BMI, surgical duration, and aneurysm diameter with an adjusted probability of postoperative acute and chronic renal dysfunction for individual cross-clamp locations.

RESULTS

Of the 4,197 patients analyzed, 405 patients (9.6%) developed renal dysfunction within 30 days with 287 patients requiring dialysis. Patients with supraceliac clamp location had the highest incidence of renal dysfunction (20.4%). Our data showed a significant association of renal dysfunction with higher BMI patients [OR 1.04 (1.02, 1.07), P = 0.001], longer operative times [OR1.01 (1.01, 1.02), P < 0.001], clamp location between the superior mesenteric artery (SMA) and renal artery [OR 1.80 (1.17, 2.78), P = 0.007] and supraceliac clamp location [OR 2.47 (1.62, 3.76), P < 0.001].

CONCLUSIONS

The incidence of renal dysfunction increases with suprarenal clamps. Patients with higher BMI, longer operative times, and increasing aneurysm diameter, and a suprarenal clamp have a significantly increased risk of renal dysfunction compared to those who also had a suprarenal clamp but lower BMI, shorter operative times and smaller aneurysm diameter.

The Incraft stent graft for the treatment of abdominal aortic aneurysms: an iliac-friendly device with an effective conventional proximal sealing mechanism

INTRODUCTION

The Incraft aortic stent graft (Cordis, Bridgewater, NJ, USA) is a trimodular endovascular stent graft with a conventional suprarenal active fixation specifically designed to overcome the anatomic limitation of small, stenotic, and tortuous iliac vessels.

AREAS COVERED

The present article provides a complete description of the Incraft stent graft, its clinical performance, its technical characteristics as well as a comparison with other competitive endografts.

EXPERT OPINION

The Incraft stent graft is an EVAR ultra low-profile device initially designed for overcoming the limitation of the hostile iliac anatomy. Recently, the device is being increasingly used in real-world conditions and not only in complex iliac anatomies with good mid-term results. Whether it remains a useful EVAR toolbox or will become a workhorse endograft is yet to be determined.

Incidence and predictive factors for endograft limb patency of the Fenestrated Anaconda™ endograft used for complex endovascular aneurysm repair

OBJECTIVE

To describe the incidence, risk factors and outcomes of treatment for limb occlusion in patients treated for complex (thoraco-)abdominal aortic aneurysms (AAA) with the Fenestrated Anaconda™.

METHODS

Between June 2010 and May 2018, 335 patients underwent elective fenestrated aortic aneurysm repair in 11 participating centers using the Fenestrated Anaconda™ with a median follow-up of 14.3 months (IQR 27.4). The primary outcome measure was freedom-from-limb-occlusion. Secondary outcome measures were freedom-from-limb-related-reintervention, secondary patency, and risk factors associated with limb occlusion.

RESULTS

Thirty (9.0%) patients presented with limb occlusion during follow-up with freedom-from-limb-occlusion of 98.5%, 91.2%, and 81.7% at 30-days, 1 and 5 years, respectively. In 87% of cases, no obvious cause for limb occlusion was documented. Primary occlusion occurred within 30-days in 36.7% and within 1 year in 80.0%. Twenty-three (6.9%) patients underwent an occlusion-related reintervention; seven (23.3%) patients were treated conservatively. Freedom-from-limb-occlusion-related-reintervention at 30-days, one and five years was 97.8%, 93.2% and 88.6%, respectively. Secondary patency was 91.3% after 1-month and 86.2% after 1 and 5 years, respectively. Female sex (OR 3.27 - 95% CI 1.28 to 8.34, P = .01) was a statistically significant predictor for limb occlusion. A higher percentage of thrombus in the aneurysm sac appeared to be protective for limb occlusion (0% compared to <25%: OR 0.22 - 95% CI 0.07 to 0.63, P = .01; 0% compared to 25-50%: OR 0.20 - 95% CI 0.07 to 0.57, P = .00 and 0% compared to >50%: OR 0.08 - 95% CI 0.02 to 0.38, P = .00), as did iliac angulation (OR 0.99 - 95% CI 0.98 to 1.00, P = .04).

CONCLUSION

Limb occlusion remains a significant impediment of endograft durability in patients treated with the Fenestrated Anaconda™, especially in female patients. Controversially, a high aneurysmal thrombus load and a high degree of iliac angulation appeared to be protective for limb occlusion, for which no obvious cause could be identified.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The impact of type 1a endoleak on the long-term outcome after EVAR

OBJECTIVE

Endoleaks remains a major determinant of outcome after endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysms. The objective of this study is to evaluate the long-term impact of proximal type 1 endoleak encountered at the case end of the EVAR procedure or during follow-up.

METHODS

All patients treated with EVAR between February 2001 and August 2017 in our institution were included. Data were collected retrospectively. A descriptive analysis of subgroups with type 1a endoleak at case end or with type 1a endoleak first encountered during follow-up was performed.

RESULTS

In total, 468 patients were included for analysis. At the case end of the EVAR procedure, in 5.3% (25/468) of patients, a type 1a endoleak was seen. In 72% of cases (18/25) the type 1a endoleak spontaneously disappeared on the first follow-up computed tomography angiography and never recurred. At the end of the follow-up period, no patient in this subgroup died with a type 1a endoleak on follow-up. In 3.4% (16/468) of all cases, a type 1a endoleak was encountered for the first time during follow-up. In 87.5% (14/16) of these cases, reintervention was performed. Two patients died with a persisting type 1a endoleak during follow-up.

CONCLUSIONS

Clinicians should differentiate between the type 1a endoleak at the case end and the type 1a endoleak first occurring during follow-up. For type 1a endoleak at the case end, expectant management can be adopted. Delayed type 1a endoleak seen during follow-up rarely seals spontaneously and needs reintervention in the majority of cases.

Outcomes of thoracic endovascular aortic repair in thoracic aortic aneurysm and penetrating aortic ulcer using the Conformable Gore TAG within and outside the instructions for use

OBJECTIVE

To describe the outcome of thoracic endovascular aortic repair (TEVAR) in thoracic aortic aneurysm and penetrating aortic ulcer with respect to instructions for use status.

METHODS

Between October 2009 and September 2017, a total of 532 patients underwent TEVAR; of which 195 have been treated using the Conformable GORE® TAG® thoracic endoprosthesis (CTAG). Fifty-six patients of this cohort underwent TEVAR for thoracic aortic aneurysm/penetrating aortic ulcer using the CTAG. Depending on the preoperative computed tomography angiography findings, patients were classified as inside or outside the device's instructions for use. All inside instruction for use patients underwent postoperative reclassification regarding the instructions for use status. Study endpoints included TEVAR-related reintervention, exclusion of the pathology (endoleak type I/III), TEVAR-related mortality, and graft-related serious adverse events. The median duration of follow-up was 29.7 months (range: 0-109.4 months).

RESULTS

Of the 56 patients, 17 were primarily classified as outside instruction for use, and in additional 13 patients, TEVAR was performed outside instruction for use, leading to 30 outside instruction for use patients (53.6%). Twenty-six patients (46.4%) were treated inside instruction for use. Reintervention-free survival was lower in outside instruction for use patients (P = 0.016) with a hazard ratio of 9.74 (confidence interval 1.2-80.2; P = 0.034) for TEVAR-related reintervention. With respect to endoleak type I/III, relevant difference was detected between inside/outside instruction for use status (P = 0.012). The serious adverse event rate was 30.4%, mainly in outside instruction for use patients (P = 0.004). Logistic regression analysis indicated an association between graft-related serious adverse event/instructions for use status (odds ratio 6.11; confidence interval 1.6-30.06; P = 0.012). In-hospital death was seen more frequently in outside instruction for use patients (P = 0.12) as was procedure-related death (log-rank test: P = 0.21).

CONCLUSION

TEVAR for thoracic aortic aneurysm/penetrating aortic ulcer is frequently performed outside instruction for use despite preoperative inside instruction for use eligibility, leading to important consequences for technical/clinical outcome. Instructions for use adherence in TEVAR should be of interest for further large-scale studies.

Effects of Left Renal Vein Ligation During Open Abdominal Aortic Aneurysm Repair on Renal Function

OBJECTIVE

Left renal vein (LRV) ligation is performed during open abdominal aortic aneurysm (AAA) repair to facilitate proximal anastomosis. Its impact on short, medium, and long term renal function has not been investigated in detail using appropriately validated endpoints.

METHODS

This was a nested case control study using data from a prospectively maintained AAA institutional dataset (tertiary centre). A total of 76 patients who underwent elective open AAA repair and had LRV ligation (1 January 2012 to 1 January 2018) were individually case matched based on age (within two years), sex, estimated glomerular filtration rate (eGFR), American Society of Anesthesiologist (ASA) score, chronic kidney disease (CKD) stage, and history of diabetes with 76 patients who had open AAA repair without LRV ligation. Renal outcomes were compared between groups, including proportion of patients developing acute kidney injury (AKI) using the Kidney Disease Improving Global Outcomes (KDIGO) criteria, proportion developing major adverse kidney events (MAKE90) at 90 days (comprising mortality and/or decrease in eGFR >25%), and absolute decrease in eGFR at latest follow up.

RESULTS

A higher proportion of patients developed AKI and MAKE90 in the LRV ligation group (AKI: 11 patients [14.8%] vs. 2 [2.6%], p = .009; MAKE90: 6 [7.9%] vs. 1 [1.3%] p = .053, in the LRV ligation and the non-LRV ligation groups, respectively) - even though the difference in the MAKE90 endpoint was not statistically significant. Changes in eGFR were not statistically different in the LRV ligation group at 90 days (4.0 ± 1.1 mL/min/1.73 m²vs. 4.4 ± 2.1, p = .64) or by the time of latest follow up (median: 28 months; 3.7 ± 1.6 vs. 2.6 ± 2.0, p = .55).

CONCLUSION

Ligation of the LRV is associated with increased levels of AKI and renal deterioration in the early post-operative phase using validated reporting criteria; however, long term renal function does not seem to be affected.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

Outcomes of Endovascular Aneurysm Repair Using the Anaconda Stent-Graft

Purpose: To report outcomes of elective endovascular aneurysm repair (EVAR) using the Anaconda stent-graft in a tertiary vascular center. Materials and Methods: A retrospective study was conducted of 271 patients (mean age 71.5 years; 260 men) who underwent elective EVAR for abdominal aortic aneurysm using the Anaconda stent-graft from January 2006 to January 2017. Median aneurysm diameter was 58 mm (range 50-90). All patients were anatomically suitable for EVAR according to the 2003 version of the instructions for use. Follow-up included computed tomography angiography at 1, 6, and 12 months and yearly thereafter for the first 4 years and then every 2 years. Primary outcomes included technical success and 30-day aneurysm-related mortality and complications; secondary outcomes were overall and aneurysm-related mortality and aneurysm-related morbidity in follow-up. Results: The Anaconda stent-graft was implanted successfully in all patients. Primary and secondary technical success rates were 99.6% and 100%, respectively. Three patients (1.1%) died within 30 days of causes unrelated to the aneurysm, while 15 patients (5.5%) suffered perioperative complications. Median follow-up was 72 months (range 14-141). The overall type I endoleak rate was 4.7% (11 proximal, 2 distal). Late aneurysm-related complications were observed in 48 patients (17.3%); aneurysm-related mortality was 1.4% (n=4). Non-aneurysm-related mortality was 21.0% (n=57). Freedom from reintervention was 95.2% at 1 year, 98% at 2 years, and 90% at 6 years. There was no significant difference in the overall limb graft occlusion rate between the second- and third-generation devices. Conclusion: Results in our cohort study demonstrate that the Anaconda stent-graft has satisfactory early and late results with low aneurysm-related mortality.

Endurant stent graft demonstrates promising outcomes in challenging abdominal aortic aneurysm anatomy

OBJECTIVE

We aimed to assess the 5-year safety and effectiveness outcomes of patients enrolled in the Endurant Stent Graft Natural Selection Global Post Market Registry (ENGAGE) who were treated outside the approved indications for use (IFU) of the Endurant stent graft.

METHODS

Our primary outcome measure was 12-month treatment success, defined as successful endograft delivery and deployment and the absence of type I or III endoleak, stent migration or limb occlusion, late conversion, and abdominal aortic aneurysm diameter increase or rupture. Secondary outcome measures included 30-day all-cause mortality, major adverse events, secondary procedures, technical observations, aneurysm-related mortality, and all-cause mortality within 12 months.

RESULTS

Demographic characteristics of ENGAGE patients treated outside (225 [17.8%]) and within (1038 [82.2%]) the IFUs were similar, except that female patients comprised a much higher percentage of the outside IFU group (19.1% vs 8.7%; P < .001). The outside IFU group presented with lower rates of coronary artery disease and cardiac revascularization and a greater number of symptomatic patients compared with the within IFU group (21.3% vs 15.0%; P = .020). Technical success was achieved in more than 99% of all patients. The outside and within IFU groups showed a comparable and low occurrence of uncorrected type I (0.9% vs 1.2%; P = 1.00) and type III endoleak (0.4% vs 0.3%; P = .54) immediately after device implantation. The 5-year freedom from type IA endoleaks was 89.4% vs 96.7% (P < .0001) for those patients outside and within the IFUs, respectively, although both groups had similar type III endoleaks through 5 years (P = .61). Stent graft limb occlusion estimated overall survival, and freedom from aneurysm-related mortality and endovascular interventions were comparable in both patient groups through the 5-year follow-up. The Kaplan-Meier estimates at 5 years showed a trend for low but increased need for type I or III endoleak correction procedures in the outside IFU group compared with the within IFU group (7.2% vs 5.2%; P = .099).

CONCLUSIONS

Differences were not observed in all-cause mortality, aneurysm-related mortality, and secondary procedures between within and outside IFU patients through a 5-year follow-up in the ENGAGE registry. Proximal necks with angulation or diameters outside the IFUs were the most common reasons for patients identified as being outside IFU, and the cohort had increased incidence of type IA endoleaks. Despite the challenges presented from the broad range of aortic and abdominal aortic aneurysm morphologies, the Endurant stent graft showed promising 5-year outcomes.

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

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

Analysing the Society for Vascular Surgery and American Association for Vascular Surgery scoring systems for outcomes post-endovascular aortic repair

BACKGROUND AND AIMS

Assess the association between the Society for Vascular Surgery/American Association for Vascular Surgery (SVS/AVSS) (Rutherford et al., J Vasc Surg 26: 517-38, 1997; Chaikof et al., J Vasc Surg 35:1061-6, 2002) medical comorbidity scoring scheme (MCS), and the global scoring system (GS) and major morbidity and mortality after elective endovascular aneurysm repair. Primary end points were peri-operative morbidity and mortality. Secondary end points were intensive care unit admission, high dependency unit admission, total stay > 5 days and 2-year mortality.

METHODS

The project was approved by the Galway Clinical Research Ethics Committee. This project followed the Declaration of Helsinki. Binary logistic regression was performed to assess the association of the scores and their individual components with the primary and secondary outcomes. Results were reported as odds ratio (OR) per point increase in score with 95% confidence intervals (CI) and the Hosmer-Lemeshow (HL).

RESULTS

Between 2002 and 2015, 401 patients underwent elective EVARs. MCS was calculated for 396 patients while GS was calculated for 183 patients. The MCS (OR 1.906, CI 1.017-3.574, p = 0.044) was associated with perioperative morbidity. The MCS was associated with perioperative mortality (OR 8.875, CI 1.918-41.070, p = 0.005). The GS was associated with perioperative morbidity (OR 11.929, CI 1.151-123.584, p = .038) but not associated with perioperative mortality (OR 3.62, CI 0.006-2118.148, p = .692).

CONCLUSIONS

The MCS shows association with perioperative morbidity and mortality. GS shows association with perioperative morbidity but not perioperative mortality; however, this may be due to our study being underpowered. We believe that the analysis of higher numbers of patients could unmask trends in both of these scores and individual components of both scores changed.

Aortic Isthmus Narrowing after Endovascular Repair of Acute Traumatic Aortic Transection

Purpose

The traumatic transection is located in the normal sized aortic isthmus where the angle is curved. We found a reversal of upper and lower blood pressure differences among patients who underwent thoracic endovascular aortic repair (TEVAR) for transection of the thoracic aorta. We investigated the isthmus stenosis in patients who underwent TEVAR for aortic injury using computed tomography.

Materials and Methods

Sixteen patients who underwent TEVAR for transection were divided in two groups: the aortic narrowing (AN) group and the non-aortic narrowing (NAN) group. AN was defined as stent graft folding more than 5 mm at the isthmus confirmed by computed tomography. The length of aorta at isthmus, pseudoaneurysm, and angle of isthmus were measured.

Results

AN was noted in five patients (31.3%). The area index in the NAN group (2.16±0.35 cm²/m²) was larger than that in the AN group (1.74±0.77 cm²/m²). The size of the pseudoaneurysm in the NAN group (31.9±4.2 mm) was smaller than that in the AN group (37.4±7.5 mm). The distance from the subclavian artery in the NAN group (15.7±9.3 mm) was longer than that in the AN group (8.4±3.2 mm) but not statistically significant. The angle of the isthmus in the NAN group (131±6 degrees) was larger than that in the AN group (107±3 degrees), and this was the only statistically significant difference (P=0.002).

Conclusion

AN by stent graft folding should be considered when performing TE-VAR in aortic injury with an acute angle of the isthmus less than 110 degrees.

The Influence of Unfavorable Aortoiliac Anatomy on Short-Term Outcomes after Endovascular Aortic Repair

Background

Endovascular aortic repair (EVAR) is widely performed to treat infrarenal abdominal aortic aneurysms (AAAs), and related techniques and devices continue to be developed. Although continuous attempts have been made to perform EVAR in patients with unfavorable aortic anatomy, the outcomes are still controversial. This study examined the short-term outcomes of EVAR for the treatment of infrarenal AAAs in patients with a ‘hostile’ neck and unfavorable iliac anatomy.

Methods

Thirty-eight patients who underwent EVAR from January 2012 to December 2017 were enrolled in this study. A hostile neck was defined based on neck length, angulation, the presence of an associated thrombus, or a conical shape. Unfavorable iliac anatomy was considered to be present in patients with a short common iliac artery (<15 mm) or the presence of aneurysmal changes.

Results

No perioperative mortality was recorded. No significant differences were found depending on the presence of a hostile neck, but aneurysmal sac shrinkage was significantly less common in the group with unfavorable iliac anatomy (p=0.04). A multivariate analysis performed to analyze the risk factors for aneurysmal progression revealed only unfavorable iliac anatomy to be a risk factor (p=0.02).

Conclusion

Patients with unfavorable aortic anatomy showed relatively satisfactory short-term outcomes after EVAR. No difference in the surgical outcomes was observed in patients with a hostile neck. However, unfavorable iliac anatomy was found to inhibit the shrinkage of the aneurysmal sac.

Comparative study of clinical outcome of endovascular aortic aneurysms repair in large diameter aortic necks (>31 mm) versus smaller necks

BACKGROUND

This study compares short-term (30 days) and intermediate term (3 years) clinical outcomes in patients with large (≥31 mm) versus small aortic neck diameters (≤28 and ≤31 mm).

METHODS

Prospectively collected data from 741 patients who underwent endovascular aortic aneurysm repair were analyzed. Some surgeons have reported the threshold for a large aortic neck for endovascular aortic aneurysm repair to be 28 mm, whereas for others it is 31 mm. Therefore, we classified aortic neck diameter into less than or equal to 28 versus greater than 28 mm; and less than or equal to 31 versus greater than 31 mm. Logistic regression and Kaplan-Meier analyses were used to compare outcomes.

RESULTS

There were 688 patients who had a defined aortic neck diameter: 592 with less than or equal to 28 mm, 96 with greater than 28 mm, 655 with less than or equal to 31 mm, and 33 with greater than 31 mm. The mean follow-up was 25.2 months for less than or equal to 31 mm versus 31.8 months for greater than 31 mm. Clinical characteristics were similar in all groups, except that there were more patients outside the instructions for use in the greater than 31 mm versus less than or equal to 31 mm group (94% vs 44%; P < .0001). There was a significant increase in early type I endoleak for patients with an aortic neck diameter of greater than 31 versus less than or equal to 31 mm (9 [27%] vs 74 [11%]; P = .01); late type I endoleaks (4 [14%] vs 18 [3%]; P = .01); sac expansion (5 [17%] vs 28 [5%]; P = .01); late intervention (5 [17%] vs 23 [4%]; P = .01); and death (9 [31%] vs 48 [8%]; P < .0001). There were no differences in outcomes between the patients with greater than 28 mm aortic neck diameters and the less than or equal to 28 mm diameters. Freedom from late type I endoleak at 1, 2, and 3 years were 96%, 88%, and 88% for patients with a neck diameter of greater than 31 mm versus 97%, 97%, and 97% for a diameter less than or equal to 31 mm (P = .19). The rate of freedom from sac expansion for patients with a diameter greater than 31 mm was 88%, 81%, and 81% at 1, 2, and 3 years versus 99%, 97%, and 92% for a diameter less than or equal to 31 mm (P = .02). Freedom from late intervention for 1, 2, and 3 years for patients with a diameter greater than 31 mm were 91%, 91%, and 91% versus 99%, 97%, and 96% for those with a diameter less than or equal to 31 mm. Survival rates at 1, 2, and 3 years for a diameter greater than 31 mm were 83%, 74%, and 68% versus 96%, 92%, and 90% for a diameter less than or equal to 31 mm (P < .001). Multivariate logistic regression analysis showed that patients with a diameter greater than 31 mm had an odds ratio of 6.1 (95% confidence interval [CI], 2.2-16.8) for mortality, 4.7 (95% CI, 1.4-15.5) for sac expansion, and 4.9 (95% CI, 1.4-17.4) for late type I endoleak.

CONCLUSIONS

Patients with large aortic neck diameters (>31 mm) had higher rates of early and late type I endoleak, sac expansion, late intervention, and mortality.

Sex-dependent outcomes following elective endovascular aortic repair

BACKGROUND

Evidence has shown that women derive less benefit from endovascular aortic repair (EVAR) in large part due to more challenging aortoiliac anatomy. This study sought to examine whether sex-dependent outcomes exist following elective EVAR cases.

METHODS

An institutional retrospective review was performed on patients who underwent elective EVAR procedures between 2008 and 2014. Outcome data collected included procedural and hospital morbidity, mortality, and overall EVAR durability based on the incidence of unplanned graft-related secondary interventions (SIs) (e.g., open conversion, proximal or distal extensions, and coil embolizations).

RESULTS

One hundred eighty-one patients (150 men, 31 women) met the study inclusion criteria. Median follow-up was 40.3 mo. Women had more challenging anatomy compared to men including smaller overall iliac diameters (6.8 mm versus 8.0 mm, P < 0.001) and more severe iliac angulation (77% moderate to severe versus 44%, P < 0.001). Women had increased risk of postoperative complications compared to men (41.9% versus 11.3%, P = 0.003). There was no perioperative mortality in our series of elective EVAR cases. Median 5-y survival following EVAR was 64.4% for men and 76.3% for women (P = 0.599). Late SI rates following EVAR was 10.5% with 16 (10.7%) men and 3 (9.7%) women needing interventions (P = 0.870). Overall durability of EVAR extrapolated as time to SIs was 91% at 2 y and 85% at 5 y. Factors predisposing SIs were iliac tortuosity (P = 0.046), aortic neck angle (P = 0.022), and endoleak at the follow-up (P = 0.030).

CONCLUSIONS

In this study, immediate outcomes following EVAR were different between men and women, with women having increased rates of postoperative complications. Mortality and overall long-term durability of EVAR, however, were the same between sexes despite anatomical differences. EVAR durability was significantly dependent on the severity of iliac tortuosity, aortic neck angulation, and presence of endoleak at the follow-up.

Outcomes of using endovascular aneurysm repair with active fixation in complex aneurysm morphology

OBJECTIVE

The ideal treatment option for patients with complex aneurysm morphology remains highly debated. The aim of this study was to investigate the impact of endovascular aneurysm repair (EVAR) with active fixation on outcomes in patients with complex aneurysm morphology.

METHODS

There were 340 consecutive patients who underwent EVAR using active fixation devices, 234 with active infrarenal fixation (AIF; Gore Excluder; W. L. Gore & Associates, Flagstaff, Ariz) and 106 with active suprarenal fixation (ASF; 85 Medtronic Endurant [Medtronic, Santa Rosa, Calif] and 21 Cook Zenith [Cook Medical, Bloomington, Ind]). Demographics, comorbidities, anatomic features, and outcomes were analyzed for patients receiving devices with active fixation. Outcomes of using active fixation in necks with <15-mm neck lengths, >60-degree infrarenal neck angle (β), >30-mm infrarenal neck diameter, severe aortic neck calcification or thrombus, and nonstraight neck morphology were evaluated.

RESULTS

Of the 340 patients, 106 (78 men; mean age, 74.5 ± 9.3 years at the time of surgery) received implants with ASF and 234 (191 men; mean age, 74.6 ± 8.9 years at the time of surgery) received implants with AIF. In comparing AIF and ASF devices, patients in the suprarenal fixation group had significantly shorter follow-up time (25 ± 17 months vs 44.3 ± 32 months; P < .0001). Patients in the ASF group had shorter aortic neck lengths (25.5 ± 15.1 mm vs 28.6 ± 14.9 mm; P = NS) and significantly larger infrarenal neck diameters (25.9 ± 6.3 mm vs 23.4 ± 3.2 mm; P < .0001) and aneurysm diameters (59.9 ± 11.6 mm v. 55.9 ± 10.0 mm; P = .002). Outcomes were similar between groups, with no significant differences in reintervention, proximal endoleak, sac growth, abdominal aortic aneurysm-related death, or rupture. Of the complex anatomic neck features investigated, neck diameter >30 mm and nonstraight neck morphology had the highest rates of reintervention in ASF devices.

CONCLUSIONS

In cases of hostile infrarenal neck morphology, ASF appears to be used more frequently. Our data suggest that ASF may be useful for certain patients but may be unfavorable for others, such as those with wide necks or several difficult neck features. Nevertheless, further research is needed to evaluate more optimal treatment options, such as fenestrated EVAR, branched EVAR, and endovascular adjuncts such as EndoAnchors (Aptus Endosystems, Sunnyvale, Calif), in dealing with high-risk anatomic characteristics that may not be optimally managed with standard EVAR devices with active fixation.

Hostility of proximal aortic neck anatomy in relation to abdominal aortic aneurysm size and its impact on the outcome of endovascular repair with the new generation endografts

BACKGROUND

To assess the relation of abdominal aortic aneurysm (AAA) diameter with the proximal neck anatomy (PNA) hostility and to evaluate its impact on the endovascular aneurysm repair (EVAR) outcomes with the use of newer generation endografts.

METHODS

Retrospective analysis of single institution's recorded data from February 2009 to April 2016. Patients' characteristics, comorbidities, aortic morphology, perioperative characteristics and outcomes were analyzed. In relation to AAA diameter 2 groups were identified: group A (50-55 mm) and group B (>55 mm). Hostile PNA was defined based on: neck diameter >28 mm, length <15 mm, angulation >60o, and circumferential thrombus and/or calcification >50%. The aortic neck scoring system was calculated. Multiple logistic regression analysis with a forward likelihood ratio method adjusted for age and gender was undertaken.

RESULTS

Three hundred seventeen patients (96% males, mean age 72.4±9 years, 80% elective) were follow-up for a mean of 23.4 months (range, 3-86 months). No differences were observed in demographics and co-morbidities between the two groups (group A: 134, 42% vs. group B: 183, 58%). Hostile PNA was present in 147/317 (46%) patients and significantly more likely to be present in group B (P<0.001). In group B the aortic neck score was higher (P<0.001), the likelihood for having hostile PNA increased for neck diameter by 2.2-fold (OR 2.2, P=0.013, 95% CI: 1.18-4.03), length by 2.3-fold (OR 2.3, P=0.012, 95% CI: 1.20-4.51), angle by 4.8-fold (OR 4.8, P=0.002, 95% CI: 1.79-13.24) and presence of thrombus by 1.5-fold (OR 1.5, P=0.037, 95% CI: 1.45-10.34). No association existed for neck calcification (P=0.071). Technical success, adjunctive procedures, perioperative characteristics and outcomes were comparable in friendly and hostile PNAs.

CONCLUSIONS

PNA hostility is more likely in AAA with diameter >55 mm but with the use of newer generation endografts this did not influence the short- and mid-term EVAR outcomes. Longer follow-up is needed for a more definite conclusion.

A Systematic Review of Predictors of Reintervention After EVAR: Guidance for Risk-Stratified Surveillance

BACKGROUND

Current surveillance protocols after endovascular aneurysm repair (EVAR) are ineffective and costly. Stratifying surveillance by individual risk of reintervention requires an understanding of the factors involved in developing post-EVAR complications. This systematic review assessed risk factors for reintervention after EVAR and proposals for stratified surveillance.

METHODS

A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed using EMBASE and MEDLINE databases to identify studies reporting on risk factors predicting reintervention after EVAR and proposals for stratified surveillance.

RESULTS

Twenty-nine studies reporting on 39 898 patients met the primary inclusion criteria for reporting predictors of reintervention or aortic complications with or without suggestions for stratified surveillance. Five secondary studies described external validation of risk scores for reintervention or aortic complications. There was great heterogeneity in reporting risk factors identified at the pre-EVAR, intraoperative, and post-EVAR stages of treatment, although large preoperative abdominal aortic aneurysm diameter was the most commonly observed risk factor for reintervention after EVAR.

CONCLUSION

Existing data on predictors of post-EVAR complications are generally of poor quality and largely derived from retrospective studies. Few studies describing suggestions for stratified surveillance have been subjected to external validation. There is a need to refine risk prediction for EVAR failure and to conduct prospective comparative studies of personalized surveillance with standard practice.

Could Preoperative Neck Anatomy Influence Follow-up of EVAR?

BACKGROUND

The aim of the study was to assess the clinical utility of strict CT scan surveillance after endovascular abdominal aneurysm repair (EVAR) and evaluate whether the anatomy of abdominal aortic aneurysm (AAA) neck (favorable/hostile) influences regular imaging control.

METHODS

A retrospective study of AAA patients who underwent EVAR with aortobi-iliac endoprostheses during 2006-2013 was conducted. Exclusion criteria included other types of devices. Variables analyzed were technical and clinical success, morbimortality, complications (such as endoleaks, sac enlargement), reinterventions, reintervention-free survival, and survival rate. Preoperative CT scans were performed and repeated at 1, 6 (in selective cases), 12, and 24 months postoperatively. Patients were divided into two groups according to preoperative anatomic characteristics: group I (favorable neck) and group II (hostile neck: angle > 60°, length < 15 mm, diameter > 28 mm, and calcification or circumference thrombus ≥50%).

RESULTS

A total of 127 patients with AAA (96.8% male) were included in the study. The mean age of the patients was 75.9 years (range: 51-90 years). The mean AAA diameter was 62.1 mm. Hostile neck was found in 52 patients (40.9%). The technical and clinical success rate was 100% and 30-day mortality was 0.8%. The reintervention-free survival rate was 97.6%, 96.1%, and 93.7% and the survival rate was 97.6%, 96.9%, and 91.3%, during follow-up at 6, 12, and 24 months, respectively. Accumulated complications in proximal sealing occurred in 0%, 0%, and 1.6% in group I and 1.9%, 6.1%, and 7.7% in group II at 1, 12, and 24 months, respectively. Type II endoleaks occurred in 24.3%, 14.3%, and 11.4% in group I and 9.8%, 6.3%, and 6.8% in group II at 1, 12, and 24 months, respectively. No increased diameter was detected at 6 and 12 months. No differences were observed in reinterventions and mortality rate depending on anatomy.

CONCLUSIONS

CT scans performed at 6 and 12 months postoperatively did not detect complications or need for reintervention in patients with favorable necks, even in the presence of endoleaks type II, and could therefore be omitted. Hostile necks may compromise proximal sealing and require regular imaging follow-ups.

Midterm Results of Proximal Aneurysm Sealing With the Ovation Stent-Graft According to On- vs Off-Label Use

Purpose: To compare the use of the Ovation stent-graft according to the ≥7-mm neck length specified by the original instructions for use (IFU) vs those treated off-label (OL) for necks <7 mm long. Methods: A multicenter retrospective registry (TriVascular Ovation Italian Study) database of all patients who underwent endovascular aneurysm repair with the Ovation endograft at 13 centers in Italy was interrogated to identify patients with a minimum computed tomography (CT) follow-up of 24 months, retrieving records on 89 patients (mean age 76.4±2.4 years; 84 men) with a mean follow-up of 32 months (range 24–50). Standard CT scans (preoperative, 1-month postoperative, and latest follow-up) were reviewed by an independent core laboratory for morphological changes. For analysis, patients were stratified into 2 groups based on proximal neck length ≥7 mm (IFU group, n=57) or <7 mm (OL group, n=32). Outcome measures included freedom from type Ia endoleak, any device-related reintervention, migration, and neck enlargement (>2 mm). Results: At 3 years, there was no aneurysm-related death, rupture, stent-graft migration, or neck enlargement. There were no differences in terms of freedom from type Ia endoleak (98.2% IFU vs 96.8% OL, p=0.6; hazard ratio [HR] 0.55, 95% CI 0.02 to 9.71 or freedom from any device-related reintervention (92.8% IFU vs 96.4% OL, p=0.4; HR 2.42, 95% CI 0.34 to 12.99). In the sealing zone, the mean change in diameters was −0.05±0.8 mm in the IFU group and −0.1±0.5 mm in the OL group. Conclusion: Use of the Ovation stent-graft in patients with neck length <7 mm achieved midterm outcomes similar to patients with ≥7-mm-long necks. These midterm data show that the use of the Ovation system for the treatment of infrarenal abdominal aortic aneurysm is not restricted by the conventional measurement of aortic neck length, affirming the recent Food and Drug Administration–approved changes to the IFU.

One Year Outcome Using Newer Generation Endografts: A National Multicenter Study on Real Word Practice

BACKGROUND

The aim of this study was to assess the 1 year outcomes following endovascular aortic aneurysm repair (EVAR) with the use of newer generation endografts.

METHODS

Retrospective analysis was conducted of prospectively collected multicenter data from 385 EVARs. Newer endografts were defined as those introduced after 2004. Patients' demographics and comorbidities, type of operation, and abdominal aortic aneurysm (AAA) morphological characteristics were analyzed. Computer tomography was performed 1 month and 1 year post-EVAR.

RESULTS

Mean age of the patients was 71.3 years; in 335 cases the intervention was elective. The mean AAA sac, neck diameter, and length were 57.15, 24.5, and 28.97 mm, respectively. Ninety-four endoleaks were recorded in 92 patients (25%), including 11 type 1a (T1aE), 3 type 1b, and 78 type 2 (T2E) endoleaks. On logistic regression analysis, neck diameter >30 mm (P = 0.032) and initial AAA sac diameter >55 mm (P = 0.031) were associated with T1aE. No association was found with T2E. Overall, 107 (27%) patients had sac expansion at 1 year associated with the presence of T2E (P = 0.019). No association was observed between T1aE or T2E and specific endograft.

CONCLUSIONS

Newer generation endografts show very satisfactory performance even in difficult anatomies. T1aE was associated with initial sac and neck diameter, while AAA sac expansion was associated with the presence of T2E.