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

OBJECTIVES: The aim of this study was to assess whether the ratio of the mean infrarenal neck diameter to the suprarenal aortic diameter is a predictor for a durable proximal seal after endovascular aneurysm repair (EVAR). METHODS: A total of 439 patients who underwent elective EVAR between 2004 and 2018 in a single vascular referral center met our inclusion criteria. Ratios were calculated by dividing the mean infrarenal neck diameter by 4 different suprarenal aortic diameters. Patients who developed a late type 1A endoleak (n=20) or proximal neck dilatation mandating revision (n=8) were compared with the 411 patients without long-term proximal seal complications. RESULTS: Patients who developed a late type 1A endoleak had more frequently hypertension, a shorter infrarenal neck length, and a larger mean infrarenal neck diameter. The ratio of the mean infrarenal neck diameter to all 4 suprarenal aortic diameters was higher in the late type 1A endoleak group compared with the group without a late type 1A endoleak. Least absolute shrinkage and selection operator (LASSO) logistic regression identified a combination of 6 variables as the best combination to predict a late type 1A endoleak: presence of hypertension, increased mean infrarenal neck diameter, decreased aneurysm neck length, larger ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the superior mesenteric artery (SMA), larger ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the upper renal artery, and increased ß-angle. Of these, based on both the univariate area under the curve (AUC) and optimal LASSO model restricted to a single predictor, the ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the SMA (AUC, 0.770; cutoff value, 0.997) was considered the best prognostic variable. CONCLUSION: The ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the SMA is a good predictor for a late type 1A endoleak. Patients with mean infrarenal neck diameter larger than the diameter proximal to the SMA (ratio >1) are at risk for a late type 1A endoleak. CLINICAL IMPACT: In this single-center, retrospective cohort study, we found that the ratio of the mean infrarenal neck diameter to the aortic diameter proximal to the SMA is a good predictor for a late type 1A endoleak. We conclude that the suprarenal diameter must be taken into account before assessing endovascular aortic aneurysm repair eligibility. Patients with a ratio >1 may not be the best candidates for a durable result after EVAR and may be better off with fenestrated EVAR or open repair.

Long-Term Outcomes of Endovascular Repair Within and Outside the Instructions for Use in Korean Patients With Abdominal Aortic Aneurysm.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has been used worldwide to treat abdominal aortic aneurysms (AAAs). Outcomes after EVAR within and outside the instruction for use (IFU) remain controversial. We analyzed long-term outcomes of EVAR within-the-IFU compared with that outside-the-IFU and baseline clinical/anatomical characteristics that influence outcomes of EVAR. METHODS: The study included 546 patients who underwent EVAR for infrarenal AAA from 1997 to 2021 at 2 Korean medical centers. The primary endpoint was graft-related adverse events (GRAEs), including type 1 or 3 endoleak, reintervention (included open conversion), aneurysm sac enlargement, aneurysm-related mortality (ARM), rupture, stent-graft migration, and stent thrombotic occlusion. RESULTS: The patients who underwent EVAR outside the IFU were 287 (52.6%). A neck angle of >60° was most common outside the IFU criteria (n=146, 50.9%). This study revealed that patients outside the IFU had a higher rate of GRAEs compared with patients within the IFU (hazard ratio [HR]: 1.879; 95% confidence interval [CI]: 1.045-2.386). A neck angle of >60° was a significant risk factor for GRAEs (adjusted HR: 2.229; 95% CI: 1.418-3.503), type 1 or 3 endoleak (adjusted HR: 2.640; 95% CI: 1.343-5.189), and reintervention (adjusted HR: 1.891; 95% CI: 1.055-3.388). CONCLUSIONS: Our study revealed EVAR with outside the IFU was associated with increased GRAEs, mainly attributed to endoleak and ARM, compared with EVAR with within the IFU. In addition, severe neck angulation was an independent risk factor for GRAEs, type 1 or 3 endoleak, and reintervention. CLINICAL IMPACT: Our study revealed endovascular aneurysm repair (EVAR) with outside-the-instruction for use (IFU) was associated with increased graft-related adverse events (GRAEs) compared with EVAR with within-the-IFU. In the low-risk population, the incidence of GRAEs and Aneurysm related mortality were higher in the outside-the-IFU group rather than within-the-IFU group. In addition, severe neck angulation was an independent risk factor for GRAEs, type 1 or 3 endoleak and reintervention.

Combined ascending aortobiiliac bypass and endovascular obliteration in the Bentall procedure for dual aortic aneurysms.

Patients with Marfan syndrome who present with a dual aortic aneurysm are not uncommon in clinical practice; however, the management of these patients is a significant challenge. We present a unique case of aortic root aneurysm and challenging infrarenal abdominal aortic aneurysm (AAA) with a short and angulated neck. We performed simultaneous repair using the Bentall procedure and ascending aortobiiliac bypass. Endovascular obliteration of the AAA neck and bilateral common iliac arteries was also performed. The perioperative process was uneventful. Normal functioning of the mechanical valve and complete thrombosis of the AAA sac were confirmed on follow-up computed tomography and echocardiography. This report suggests that combined ascending aortobiiliac bypass and endovascular obliteration with the Bentall procedure for dual aortic aneurysm is a useful surgical strategy for patients with Marfan syndrome. Life-long follow-up and medication ought to be mandatory to prevent incomplete exclusion and bypass occlusion.

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

PURPOSE: To report outcomes of endovascular repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs) with currently-available endografts and identify predictors of technical/clinical failure. MATERIALS AND METHODS: Patients undergoing EVAR between 2012 and 2020 were prospectively collected and retrospectively analyzed. Technical success (TS: no type I-III endoleaks, renal/hypogastric arteries loss, iliac leg occlusion, conversion to open repair and mortality within 24 postoperative hour), proximal neck-related TS (nr-TS: no proximal type I endoleaks, unplanned renal arteries coverage), and 30-day mortality were assessed as early outcomes. Proximal type I endoleak (ELIa), survival and freedom from reinterventions (FFRs) were assessed during follow-up. Uni/multivariate analysis and Cox-regression were used to identified factors associated with early and follow-up outcomes; FFR and survival were assessed by Kaplan-Meier analysis. RESULTS: A total of 710 were included. Technical success and nr-TS were 692 (98%) and 700 (99%), respectively. The presence of ≥2 hostile anatomical infrarenal neck characteristics was associated with technical failure (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.3-4.1; p: 0.007). Infrarenal neck angle >90° (OR: 2.88; 95% CI: 9.6-50.3; p: 0.004), barrel shape (OR: 2.33; 95% CI: 11.1-100.3; p: 0.02) or presence of ≥2 hostile anatomical infrarenal neck characteristics (OR: 2.16; 95% CI: 2.5-5.3; p: 0.03) were independent risk factors for neck-related technical failures. Six (0.8%) patients died within 30 postoperative days. Chronic obstructive pulmonary disease (OR: 16; 95% CI: 1.1-218.3; p: 0.04) and urgent repair (OR: 15; 95% CI: 1.8-119.6; p: 0.01) were independent risk factors for 30-day mortality. The mean follow-up was 53±13 months. There were 12 (1.7%) ELIa during follow-up. Infrarenal neck length <15 mm (hazard ratio [HR]: 2.8; 95% CI: 1.9-9.6; p: 0.005), diameter >28 mm (HR: 2.7; 95% CI: 1.6-9.5; p: 0.006), angle ≥90° (HR: 2.7; 95% CI: 8.3-50.1; p: 0.007), and persistent type II endoleak (HR: 2.9; 95% CI: 1.6-10.1; p: 0.004) were independent risk factors for ELIa. Freedom from reintervention was 91% at 5 years. The ELIa was an independent risk factor for reinterventions during follow-up (HR: 29.5; 95% CI: 1.4-1.6; p<0.001). Survival was 74% at 5 years with 2 cases (0.3%) of late aortic-related mortality. Peripheral arterial occlusive disease (HR: 1.9; 95% CI: 1.4-3.65; p: 0.03), aneurysm diameter ≥65 mm (HR: 2.2; 95% CI: 1.4-3.26; p<0.001), and infrarenal neck length <15 mm (HR: 1.7; 95% CI: 1.2-2.35; p: 0.04) were independent risk factors for mortality during follow-up. CONCLUSION: Endovascular repair with currently-available endografts has high TS and low 30-day mortality. Survival and FFRs were satisfactory at mid-term. Pre/postoperative risk factors for technical and clinical failure were identified and they should be considered in EVAR indication and postoperative management to reduce complications and improve mid-term outcome. CLINICAL IMPACT: Pre and postoperative risk factors for technical and clinical EVAR failure can be identified and they should be considered in EVAR indication and postoperative management to reduce complications and improve mid-term outcome.

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

OBJECTIVES: Aortic diameters may differ significantly between patients with different gender and body size. The aim of this study was to relate absolute aortic diameters to age, sex, height, and weight of the patients and to correct for these factors by calculating the ratio between the infrarenal and the suprarenal aortic diameters. METHODS: A total of 458 patients who underwent elective endovascular aneurysm repair (EVAR) between 2004 and 2018 were included. The aortic anatomy in this group of elective EVAR patients was compared with a control group of 75 patients without an abdominal aortic aneurysm (AAA). The aortic diameter was measured at 4 suprarenal points and 4 infrarenal points. Ratios were calculated by dividing the mean infrarenal neck diameter by 4 suprarenal measurements. RESULTS: Patients in the aneurysm group had significantly larger suprarenal and infrarenal aortic diameters. The ratios between the mean infrarenal neck diameter and all 4 suprarenal measurements were larger in the AAA group than in the control group. In both groups, there was a significant correlation between the mean infrarenal neck diameter and sex, height, weight, and body surface area (BSA). However, in both groups, all 4 ratios between the mean infrarenal neck diameter and suprarenal aortic diameters were not correlated with age, sex, height, weight, or BSA, except for the ratio between the mean infrarenal neck diameter and the aortic diameter measurement proximal to the upper renal artery, which was correlated to weight and BSA in the control group. CONCLUSION: The mean infrarenal neck diameter is correlated with sex, height, weight, and BSA. However, when the suprarenal aortic diameter was used as an internal control for the mean infrarenal neck diameter, we were able to correct for these variations in aortic diameters due to sex and body size. The clinical relevance of this ratio in patients treated by EVAR has yet to be assessed in future research. CLINICAL IMPACT: In the assessment for EVAR suitability the absolute diameter of the aneurysm neck is taken into account. We believe that using absolute diameters is not the appropriate way to assess this suitability, but that patient characteristics such as age, gender and body size, should be factored into this assessment. In this paper, we show that suprarenal and infrarenal aortic diameters are both significantly increased in patients with an aneurysm compared with patients without an aneurysm. Besides, we found that mean infrarenal aortic diameter is correlated with sex, height, weight, and body surface area. Finally, we propose a new ratio system, using suprarenal diameters as an internal control, to correct for aortic diameter variations due to sex and body size.

Endovascular Aneurysm Repair With AFX Stent-Grafts or Tube Grafts for Sacciform Infrarenal Pathologies in a Narrow Aortic Anatomy.

PURPOSE: The objective of this study was to compare the outcomes of patients treated with tube grafts and AFX stent-graft in the narrow infrarenal aortic anatomy. MATERIALS AND METHODS: Patients with penetrating aortic ulcers (PAUs) or sacciform aneurysms of the infrarenal aorta and an aortic bifurcation diameter ≤20 mm who underwent endovascular aneurysm repair (EVAR) with bifurcated AFX or tube stent-grafts (TUBE) between 2012 and 2020 were included. Demographic data and the outcome of the AFX group were compared with the TUBE group. All morphological measurements in the preoperative and postoperative computed tomography scans were performed in the aortic centerline. RESULTS: Fifty-one patients (female: 12/51; 29%; median age: 72 years [63, 77]) with a median follow-up of 10 (3, 39) months, were included, of whom 35/51 (69%) had PAUs and 11/51 were symptomatic (22%). The aortic bifurcation diameter was 17 mm (15, 18) with severe calcifications in 25/51 (49%). The distal aortic landing zone was longer in the TUBE group (9 mm vs 24 mm; p<0.001). The technical success was 96% with a median aneurysm shrinkage of 8% (3, 13), which was comparable between the groups (p=0.264). Periprocedural mortality, conversion to open surgery, myocardial infarction, and stroke were not observed. Two type Ia endoleaks (EL) and 2 type Ib EL occurred, all in the TUBE group (Type 1 EL; 19 vs 0%; p=0.013). The limb patency in the AFX group was 100%. One patient with a tube graft developed an infrarenal aortic thrombosis 40 months after the intervention. The reintervention rate in the TUBE group was higher (14 vs 0%; p=0.032) and included 3 aortic cuff implantations and 1 covered endovascular aortic reconstruction of aortic bifurcation (CERAB). CONCLUSION: AFX stent-graft showed a lower rate of type I endoleaks and reinterventions in sacciform infrarenal aortic pathologies during the early and midterm follow-up.

Endovascular Treatment of Abdominal Aortic Aneurysm With Severe Angulation of Infrarenal Aortic Neck by Gore Conformable Endograft.

INTRODUCTION: The aim of the study is to report a single-center experience with the Gore Excluder conformable endograft with active control system (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) in abdominal aortic aneurysms (AAAs) with severe infrarenal neck angulation. METHODS: All patients underwent EVAR with CEXC Device between September 2018 and 2020, were prospectively enrolled, and retrospectively analyzed. Anatomical details of the proximal aortic neck were evaluated. Early endpoints were the use of repositionability and angulation system, intraoperative unplanned cuff, technical success (TS), 30-day morbidity/mortality, and reintervention. Follow-up endpoints were type-I endoleaks, endograft migration, aortic neck dilatation, aneurismal sac shrinkage, survival (S), and freedom from reintervention (FFR). RESULTS: Twenty-five patients were enrolled (median age: 80 [range = 60-90] years, median AAA diameter: 60 [range = 52-90] mm). All patients had severe infrarenal neck angulation (beta angle ≧ 60°), and 11 (44%) of those had neck beta angle ≧ 90°. Median infrarenal neck angle, length, and diameter were 70° (range = 60°-90°), 22 (range = 13-42) mm and 22 (range = 18-31) mm, respectively. Endograft repositioning system was employed in 15 (60%) cases and the median number of repositioning maneuvers was 1 (range:0-4). Active angulation system was used in 17 (68%) patients. The median proximal diameter of the main-body and oversize were 28 (range = 23-36) mm and 28% (range = 21%-38%), respectively. Proximal cuff was positioned in 1 (4%) patient. Technical success was achieved in all cases. Intraoperative and perioperative morbidity and mortality were 12% and 0%, respectively. Perioperative type-I/III and II endoleaks were observed in 0 and 4 (16%) patients, respectively. The median follow-up was 12 months (range: 3-30). One patient died at 12-month for AAA-unrelated causes. Abdominal aortic aneurysm-sac shrinkage and stability were observed in 9 (36%) and 15 (60%) cases, respectively. No type-I/III endoleak and reintervention occurred during the follow-up. One persistent type-II endoleak was observed. Estimated survival at 24 months was 92%. CONCLUSION: According to the present data, the CEXC Device allows an excellent rate of TS in severe angulated aortic neck. This preliminary data, could increase the rate of patients eligible for EVAR.

Complication of Middle Cerebral Artery Aneurysm Surgery: An M2 Tear at the Neck, Managed with a Salvage M2-to-M2 In Situ Bypass.

An unexpected rupture at the aneurysm neck, with or without adjacent arterial injury or compromise of distal branches during microsurgical clipping, can be a challenging surgical problem to resolve. In this presented case of a neurologically intact 65-year-old woman, elective clipping of an unruptured right middle cerebral artery bifurcation aneurysm was complicated by an unexpected M2 tear at the neck, involving the origin of the frontal M2. Attempts to seal the tear directly, using various techniques, failed; therefore, it was ultimately managed with sacrifice of the vessel and a salvage side-to-side M2-to-M2 in situ bypass. Six months after surgery, the patient demonstrated moderate disability but was able to ambulate with a cane.

The association between device instructions for use adherence and outcomes after elective endovascular aortic abdominal aneurysm repair.

OBJECTIVE: Aortic neck anatomy has a significant impact on the complexity of endovascular aortic aneurysm repair (EVAR), with concern that neck characteristics outside of the instructions for use (IFU) may result in worse outcomes. Therefore, this study determined the impact of neck characteristics outside of the IFU on perioperative and 1-year outcomes and mid-term survival after EVAR. METHODS: We identified all patients undergoing elective infrarenal EVAR from December 2014 to May 2020 in the Vascular Quality Initiative database. Neck characteristics outside of the IFU were determined based the specific device IFU neck characteristics (neck diameter, length, and angulation). Patients without 1-year follow-up were excluded for the 1-year outcomes analyses (n = 6138 [40%]). We used multivariable adjusted logistic regression and Cox proportional hazard models to identify the independent associations between neck characteristics outside of the IFU and our outcomes. RESULTS: Of the 15,448 patients identified, 22.1% had neck characteristics outside of the IFU, including 6.6% with a infrarenal angle, 6.8% with a neck length, 10.4% with a neck diameter, and 1.1% with a suprarenal angulation outside of the IFU. Of these, 2.4% had more than one neck characteristic outside of the IFU. Patients with neck characteristics outside of the IFU were more often female (27.9% vs 15.0%; P < .001) and were older (median age, 75 years vs 73 years; P < .001). EVAR patients with neck characteristics outside of the IFU had higher rates of type Ia endoleaks at completion (4.8% vs 2.5%; P < .001), perioperative mortality (1.2% vs 0.6%; P < .001), 1-year sac expansion (7.1% vs 5.3%; P = .017), and 1-year reinterventions (4.4% vs 3.2%; P = .03). In multivariable adjusted analyses, neck characteristics outside of the IFU were independently associated with type Ia completion endoleaks (OR, 1.6; 95% CI, 1.3-2.0; P < .001), perioperative mortality (OR, 1.8; 95% CI, 1.2-2.7; P = .005), 1-year sac expansion (OR, 1.4; 95% CI, 1.0-1.8; P = .025), and 1-year reinterventions (OR, 1.4; 95% CI, 1.0-1.9; P = .039). The unadjusted midterm survival was lower for patients with neck characteristics outside of the IFU than for patients without (5-year survival 84.0% vs 86.7%; log-rank P < .001). However, after adjustment, survival was similar for patients with neck characteristics outside of the IFU to those within (hazard ratio, 1.1; 95% CI, 1.0-1.3; P = .22). CONCLUSIONS: Neck characteristics outside of the IFU are independently associated with completion type Ia endoleaks, perioperative mortality, 1-year sac expansion, and 1-year reinterventions among patients undergoing elective EVAR. These results indicate that continued effort is needed to improve the proximal seal in patients with neck characteristics outside of the IFU undergoing EVAR. Also, in patients with severe hostile neck characteristics, alternative approaches such as open repair, use of a fenestrated or branched device, or endoanchors should be considered.

Two Decades of Abdominal Aortic Endovascular Repair With the Anatomical FiXation at the Aortic Bifurcation in a Large Single-Center Experience.

OBJECTIVE: The introduction of new endograft models improved long-term results of abdominal aortic aneurysm (AAA) endovascular repair (EVAR), but most of them maintained an old and unchanged design: a short body and long legs shifting up the flow divider. This study assessed the long-term results of EVAR with unimodular endoprosthesis fixed at the aorto-iliac bifurcation (Anatomical FiXation), in a large, unselected cohort. MATERIALS AND METHODS: In a single-center, retrospective cohort study, 623 patients selectively treated between 1999 and 2016, were analyzed. Follow-up protocol included at least a computed tomography angiography within 3 months and a duplex ultrasound and clinical exam yearly. All enrolled patients were analyzed by 2020. The primary outcomes were technical success, clinical success, and survival. Secondary outcomes included survival-free from late-open-conversion (LOC), reintervention, and endoleaks. RESULTS: Median age was 74±11 years and the follow-up 93±54 months. The technical success was achieved in 99.4% and the 30-day clinical success was 98.4%. A 5-year clinical success of 97.7% was registered and at 10 years success was 96.7%. The overall survival at 1, 5, 10, and 15 years was 92.4%, 79.5%, 64.9%, and 45.5%, respectively. Six (0.98%) AAA-related death were registered, 3 caused by infection of the endograft and 3 for secondary rupture. LOCs were 9 (1.47%) and reintervention-free survival at 1, 5, 10, and 15 years were 88.4%, 78.0%, 76.2%, and 74.6%, respectively. Freedom from endoleaks was 88.8% at 1 year and 72.7% at 15 years. A total of 63 high-flow endoleaks were registered (43 type I, 7 type IIIa, 12 type IIIb, and 1 type Ib+IIIb). No migrations were recorded, and the graft limb thrombosis rate was 1.14%. From a multivariate analysis resulted that long-term clinical success appeared to be reduced in patients affected by diabetes [odds ratio (OR) 0.24; p=0.04] and in presence of calcified and thrombotic iliac accesses (OR 0.16; p=0.006). CONCLUSION: EVAR with the Anatomical FiXation was confirmed to be safe, feasible, and effective to prevent AAA rupture in the long term as well. However, the overall survival remains afflicted by cardiovascular accident. The original concept of unibody bifurcated design allowed a very low rate of graft thrombosis and zeroed the risk of migration and related reintervention.

Analysis of the position of EndoAnchor implants in therapeutic use during endovascular aneurysm repair.

OBJECTIVE: The aim of this study was to analyze the penetration depth, angles, distribution, and location of deployment of individual EndoAnchor (Medtronic Vascular, Santa Rosa, Calif) implants. METHODS: Eighty-six primary and revision arm patients (procedural success, 53; persistent type IA endoleak, 33) treated for type IA endoleaks with a total of 580 EndoAnchor implants from a subset of the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) were included in this study. Procedural success was defined as the absence of a type IA endoleak on the first postprocedural computed tomography scan after the EndoAnchor implantation procedure. Endograft malapposition along the circumference was assessed at the first postoperative computed tomography scans and expressed as clock-face range and width in degrees and normalized such that the center was translated to 0 degrees. The position and penetration of each EndoAnchor implant were measured as the clock-face orientation. EndoAnchor implant penetration into the aortic wall was categorized as follows: good penetration, ≥2 mm; borderline penetration, <2 mm or ≥2-mm gap between the endograft and aortic wall; or no penetration. The orthogonal and longitudinal angles between the EndoAnchor implant and the interface plane of the aortic wall were determined. Location of deployment was investigated for each EndoAnchor implant and classified as maldeployed when it was above the fabric or in a gap >2 mm between the endograft and aortic wall due to >2-mm thrombus or positioning of the EndoAnchor implant below the aortic neck. RESULTS: A total of 170 (29%) EndoAnchor implants had maldeployment and were therefore beyond recommended use and not useful. After EndoAnchor implantation, the procedural success and persistent type IA endoleak groups had 3 (1%) and 4 (2%) EndoAnchor implants positioned above the fabric as well as 60 (18%) and 103 (42%) placed in a gap >2 mm, respectively. The amount of EndoAnchor implants with good, borderline, and no penetration was significantly different between both groups (success vs type IA endoleak) after exclusion of maldeployed EndoAnchor implants (235 [87.4%], 14 [5.2%], and 20 [7.4%] vs 97 [68.8%], 18 [12.8%], and 26 [18.4%], respectively; P < .001). Good penetration EndoAnchor implants were more closely aligned with a 90-degree orthogonal angle than the borderline penetration and nonpenetrating EndoAnchor implants. The longitudinal angle was more distributed, which was observed through all three penetration groups. CONCLUSIONS: In this subcohort of ANCHOR patients, almost 30% of the EndoAnchor implants had maldeployment, which may be prevented by careful preoperative planning and measured intraoperative deployment. If endoleaks are due to >2-mm gaps, EndoAnchor implants alone may not provide the intended sealing, and additional devices should be considered.

Expanded Suitability of Ruptured Abdominal Aortic Aneurysms for Total Endovascular Repair Using the Endurant Endograft and Heli-FX EndoAnchors.

PURPOSE: To assess if the suitability of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs) can be expanded by combining the Endurant stent-graft with the Heli-FX EndoAnchors. MATERIALS AND METHODS: Contrast-enhanced computed tomography (CT) scans of 90 patients (mean age 73.2±9 years; 87 men) with RAAA admitted between January 2014 and January 2018 in 2 tertiary care centers were analyzed in a 3-dimensional workstation. Anatomical features of the aneurysms according to the instructions for use (IFU) for the Endurant endograft were evaluated and expansion of treatment with Heli-FX EndoAnchors was assessed. RESULTS: Neck length <10 mm was present in 41 (45.6%) patients; 5 had neck diameters outside the IFU and 45 (50.0%) had conical necks. Thrombus and calcium were absent in 63 (70.0%) and 73 (81.1%), respectively. In the study cohort, 44 (48.9%) patients met all the neck criteria, although overall IFU compliance was found in only 35 (38.9%) patients due to iliac-related issues in 21 patients. The adjunctive use of EndoAnchors in the entire study group would enhance the therapeutic range to an additional 24 patients, 8 of whom would need an associated iliac procedure. This represents an expansion of the total EVAR approach from 48.9% to 75.6% of cases if some iliac issues are overcome and from 38.9% to 56.7% without correcting iliac deficiencies. CONCLUSION: The main reason of being unfit for endovascular treatment in this series was neck length <10 mm. Based on this analysis, nearly 40% of RAAA patients would have been candidates for EVAR based on the IFU neck criteria for the Endurant stent-graft. This suitability could be nearly doubled with the use of EndoAnchors and correction of unsuitable iliac anatomy. The use of EndoAnchors has the potential to offer a significant benefit in the endovascular treatment of RAAA patients.

Influence of aortic neck characteristics on successful aortic wall penetration of EndoAnchors in therapeutic use during endovascular aneurysm repair.

OBJECTIVE: This study sought to quantify EndoAnchor (Medtronic Vascular, Santa Rosa, Calif) penetration into the aortic wall in patients undergoing endovascular abdominal aortic aneurysm repair and to assess predictors of successful penetration and its relationship to postprocedural type IA endoleak. METHODS: A subset of patients from the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) were included if they met the following criteria: the indication for EndoAnchor use was to treat a type IA endoleak, and postprocedure contrast-enhanced computed tomography (CT) scans of sufficient quality were available for core laboratory review. Patients undergoing implantation of cuffs or stents during the EndoAnchor implantation procedure were excluded. Baseline anatomic characteristics were recorded. The cohort was divided into patients with and without persistent type IA endoleaks at the first postoperative CT scan. Penetration of each EndoAnchor measured on this CT scan was defined as good penetration when the EndoAnchor penetrated ≥2 mm into the aortic wall, borderline penetration when EndoAnchor penetration was <2 mm or a gap remained between the endograft and aortic wall, or no penetration when the EndoAnchor did not penetrate into the aortic wall. Differences between the groups were analyzed with the Mann-Whitney U test or Fisher exact test. Multivariate analyses were performed to identify independent predictors of EndoAnchor penetration, and procedural success was defined by absence of type IA endoleak. RESULTS: Eighty-six patients of the primary (n = 61 [71%]) and revision (n = 25 [29%]) arms of the ANCHOR registry were included. There were 53 (62%) without and 33 (38%) with persistent type IA endoleaks on the first postprocedural CT scan. The median number of EndoAnchors with good penetration was significantly greater in the cohort without endoleaks, 4 (interquartile range, 3-5) vs 3 (interquartile range, 1.5-4), respectively (P = .002). A multivariate model for EndoAnchor penetration identified use of a Medtronic Endurant endograft as a factor associated with good penetration (P = .001), whereas poor penetration was associated with a larger aortic neck diameter 10 mm distal to the lowest renal artery (P < .001) and greater proximal neck calcium thickness (P = .004). EndoAnchor penetration was the only variable that attained significance (P < .001) in the multivariate model for successful treatment of a type IA endoleak. CONCLUSIONS: Adequate EndoAnchor penetration into the aortic wall is less likely when the aortic neck diameter is large or when the neck contains significant mural calcium. No penetration of the EndoAnchor was the only factor predictive of postprocedural type IA endoleak. This study stresses the importance of careful selection of patients based on preoperative assessment of the infrarenal neck on CT angiography and emphasizes careful deployment of EndoAnchors into the aortic wall to improve successful treatment of type IA endoleaks.

Validation of a New Methodology to Determine 3-Dimensional Endograft Apposition, Position, and Expansion in the Aortic Neck After Endovascular Aneurysm Repair.

PURPOSE: To validate a novel methodology employing regular postoperative computed tomography angiography (CTA) scans to assess essential factors contributing to durable endovascular aneurysm repair (EVAR), including endograft deployment accuracy, neck adaptation to radial forces, and effective apposition of the fabric within the aortic neck. METHODS: Semiautomatic calculation of the apposition surface between the endograft and the infrarenal aortic neck was validated in vitro by comparing the calculated surfaces over a cylindrical silicon model with known dimensions on CTA reconstructions with various slice thicknesses. Interobserver variabilities were assessed for calculating endograft position, apposition, and expansion in a retrospective series of 24 elective EVAR patients using the repeatability coefficient (RC) and the intraclass correlation coefficient (ICC). The variability of these calculations was compared with variability of neck length and diameter measurements on centerline reconstructions of the preoperative and first postoperative CTA scans. RESULTS: In vitro validation showed accurate calculation of apposition, with deviation of 2.8% from the true surface for scans with 1-mm slice thickness. Excellent agreement was achieved for calculation of the endograft dimensions (ICC 0.909 to 0.996). Variability was low for calculation of endograft diameter (RC 2.3 mm), fabric distances (RC 5.2 to 5.7 mm), and shortest apposition length (RC 4.1 mm), which was the same as variability of regular neck diameter (RC 0.9 to 1.1 mm) and length (RC 4.0 to 8.0 mm) measurements. CONCLUSION: This retrospective validation study showed that apposition surfaces between an endograft and the infrarenal neck can be calculated accurately and with low variability. Determination of the (ap)position of the endograft in the aortic neck and detection of subtle changes during follow-up are crucial to determining eventual failure after EVAR.

Determination of Endograft Apposition, Position, and Expansion in the Aortic Neck Predicts Type Ia Endoleak and Migration After Endovascular Aneurysm Repair.

PURPOSE: To describe the added value of determining changes in position and apposition on computed tomography angiography (CTA) after endovascular aneurysm repair (EVAR) to detect early caudal displacement of the device and to prevent type Ia endoleak. METHODS: Four groups of elective EVAR patients were selected from a dataset purposely enriched with type Ia endoleak and migration (>10 mm) cases. The groups included cases of late type Ia endoleak (n=36), migration (n=9), a type II endoleak (n=16), and controls without post-EVAR complications (n=37). Apposition of the endograft fabric with the aortic neck, shortest distance between the fabric and the renal arteries, expansion of the main body (or dilatation of the aorta in the infrarenal sealing zone), and tilt of the endograft toward the aortic axis were determined on the first postoperative and the last available CTA scan without type Ia endoleak or migration. Differences in these endograft dimensions were compared between the first vs last scan and among the 4 groups. RESULTS: No significant differences in endograft configurations were observed among the groups on the first postoperative CTA scan. On the last CTA scan before a complication arose, the position of the fabric relative to the renal arteries, expansion of the main body, and apposition of the fabric with the aortic neck were significantly different between the type Ia endoleak (median follow-up 15 months) and migration groups (median follow-up 23 months) compared with the control group (median follow-up 19 months). Most endograft dimensions had changed significantly compared with the first postoperative CTA scan for all groups. Apposition had increased in the control group but had decreased significantly in the type Ia endoleak and migration groups. CONCLUSION: Progressive changes in dimensions of the endograft within the infrarenal neck could be detected on regular CTA scans before the complication became urgent in many patients.

Editor's Choice - Influence of Proximal Aortic Neck Diameter on Durability of Aneurysm Sealing and Overall Survival in Patients Undergoing Endovascular Aneurysm Repair. Real World Data from the Gore Global Registry for Endovascular Aortic Treatment (GREAT).

OBJECTIVES: Aortic neck diameter is an independent anatomical feature that is poorly understood, yet potentially linked to proximal seal failure and adverse outcome following standard EVAR. The aim of this study was to assess whether large proximal aortic neck (LAN) diameter is associated with adverse outcome using prospectively collected individual patient data from The Global Registry for Endovascular Aortic Treatment (GREAT). METHODS: A total of 3166 consecutive patients, from 78 global centres, receiving Gore Excluder stent grafts for infrarenal abdominal aortic aneurysm repair between 2011 and 2017 were included. Patient demographics, biometrics, operative details, and clinical outcome were analysed. Patients were divided into two groups: normal baseline proximal aortic neck (NAN) diameter (<25 mm on computed tomography aortography), and LAN (≥25 mm). Clinical follow up (including imaging) was available for 76.5% of patients 5 years post-intervention. Primary endpoints analysed were Type IA endoleak and any aortic re-intervention up to 5 years post-procedure. A composite endpoint of Type IA endoleak, re-intervention, aortic rupture, or aortic related mortality was also assessed. RESULTS: A total of 1977 (62.4%) patients were classified NAN and 1189 (37.6%) were LAN. Immediate technical success was achieved in 3164 out of 3166 (>99.9%) of cases. Freedom from Type IA endoleak was achieved in 99.3% at 1 year and 97.3% at 5 years (lower in LAN vs. NAN: 96.8% [CI 93.7-98.4] vs. 98.6% [CI 94.5-99.6], p = .007). Freedom from aortic re-intervention was 93.7% at 1 year and 83.2% at 5 years (78.6% [CI 66.0-87.0] LAN vs. 86.0% [CI 81.8-89.3] NAN, p = .11). Freedom from primary composite endpoint was 95.9% at 1 year and 84.9% at 5 years (81.3% [CI 69.2-89.0] LAN vs. 87.0% [CI 81.6-91.0] NAN, p = .066). Five year survival was lower in the LAN group; 64.6% (CI 50.1-75.7) vs. 76.5% (CI 70.7-81.3), p = .03). CONCLUSION: LAN is associated with delayed Type IA endoleak occurrence and lower overall survival.

A Semiautomated Method for Measuring the 3-Dimensional Fabric to Renal Artery Distances to Determine Endograft Position After Endovascular Aneurysm Repair.

PURPOSE: To report a methodology for 3-dimensional (3D) assessment of the stent-graft deployment accuracy after endovascular aneurysm repair (EVAR). METHODS: A methodology was developed and validated to calculate the 3D distances between the endograft fabric and the renal arteries over the curve of the aorta. The shortest distance between one of the renal arteries and the fabric (SFD) and the distance from the contralateral renal artery to the fabric (CFD) were determined on the first postoperative computed tomography (CT) scan of 81 elective EVAR patients. The SFDs were subdivided into a target position (0-3 mm distal to the renal artery), high position (partially covering the renal artery), and low position (>3 mm distal to the renal artery). Data are reported as the median (interquartile range, IQR). RESULTS: Intra- and interobserver agreements for automatic and manual calculation of the SFD and CFD were excellent (ICC >0.892, p<0.001). The median SFD was 1.4 mm (IQR -0.9, 3.0) and the median CFD was 8.0 mm (IQR 3.9, 14.2). The target position was achieved in 44%, high position in 30%, and low position in 26% of the patients. The median slope of the endograft toward the higher renal artery was 2.5° (IQR -5.5°, 13.9°). CONCLUSION: The novel methodology using 3D CT reconstructions enables accurate evaluation of endograft position and slope within the proximal aortic neck. In this series, only 44% of endografts were placed within the target position with regard to the lowermost renal artery.

The Influence of Positioning of the Nellix Endovascular Aneurysm Sealing System on Suprarenal and Renal Flow: An In Vitro Study.

PURPOSE: To examine the influence of device positioning and infrarenal neck diameter on flow patterns in the Nellix endovascular aneurysm sealing (EVAS) system. METHODS: The transition of the aortic flow lumen into two 10-mm-diameter stents after EVAS creates a mismatched area. Flow recirculation may affect local wall shear stress (WSS) profiles and residence time associated with atherosclerosis and thrombosis. To examine these issues, 7 abdominal aortic aneurysm flow phantoms were created, including 3 unstented controls and 3 stented models with infrarenal neck diameters of 24, 28, and 32 mm. Stents were positioned within the instructions for use (IFU). Another 28-mm model was created to evaluate lower positioning of the stents outside the IFU (28-mm LP). Flow was visualized using optical particle imaging velocimetry (PIV) and quantified by time-averaged WSS (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) in the aorta at the anteroposterior (AP) midplane, lateral midplane, and renal artery AP midplane levels. RESULTS: Flow in the aorta AP midplane was similar in all models. Vortices were observed in the stented models in the lateral midplane near the anterior and posterior walls. In the 32-mm IFU and 28-mm LP models, a steady state of vortices appeared, with varying location during a cycle. In all models, a low TAWSS (<10-2 Pa) was observed at the anterior wall of the aorta with peak OSI of 0.5 and peak RRT of 104 Pa-1. This region was more proximally located in the stented models. The 24- and 28-mm IFU models showed flow with a higher velocity at the renal artery inflow compared to controls. TAWSS in the renal artery was lower near the orifice in all models, with the largest area in the 24-mm IFU model. OSI and RRT in the renal artery were near zero for all models. CONCLUSION: EVAS enhances vorticity proximal to the seal zone, especially with lower positioning of the device and in larger neck diameters. Endobags just below the renal artery affect the flow profile in a minor area of this artery in 24- and 28-mm necks, while lower stent positioning does not influence the renal artery flow profile.

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.

Systematic review and meta-analysis of migration after endovascular abdominal aortic aneurysm repair.

AIM: To identify patients who are under higher threat for migration because of an old generation stent graft application. METHODS: A systematic review and meta-analysis of the literature was undertaken to identify all studies which included older generation endografts and data reporting on graft migration after EVAR. Outcome data were pooled and combined, and were calculated using fixed or random effects models. RESULTS: From 2000 to 2014, 22 retrospective studies were identified reporting on stent- graft migration after EVAR (8.6%). From those patients, 39% received re-intervention with the mean time of identification ranging from 12 to 36 months. Six of these retrospective nonrandomized studies were eligible for meta-analysis. AAA diameter (AAA diameter: 0.719 mm; 95% confidence interval [CI]: 0.00065-1.4384 mm; p = 0.00497) and neck length (neck length: 4.36 mm; 95% CI: 1.3277-7.394; p = 0.0048) were the only significant factors associated with stent- graft migration. Neck diameter and neck angulation did not have any important influence on stent-graft migration. CONCLUSIONS: Patients with large AAA and short necks who were treated with older generation stent grafts such as AneurX and Talent are in higher risk for endograft migration than others. Stent- graft migration consists of an insidious and underestimated threat.