The correlation of aortic neck length to early and late outcomes in endovascular aneurysm repair patients

Hostile neck anatomy contributes to higher rates of reintervention following endovascular aortic repair for ruptured infrarenal abdominal aortic aneurysm

INTRODUCTION

Ruptured abdominal aortic aneurysms (AAA) presenting with hostile neck anatomy can represent a challenge in surgical decision-making. We hypothesized that, patients who require reinterventions have higher rates of compromised neck anatomy at initial presentation and may indicate a need for altered surveillance paradigm.

METHODS

Patients presenting with ruptured AAA to a single tertiary care institution from 2014 to 2021 were retrospectively reviewed. Those treated with infrarenal EVAR, with no prior aortic surgeries, and with available pre-operative computed tomography (CT) scans were included. Demographics, timing and type of reintervention, follow-up, and survival were collected. CT scans were assessed for hostile neck anatomy via measurements of diameter, length, angle, taper, bulge, calcification, and thrombus. Demographics, comorbidities, and neck anatomy of those with and without reintervention were compared using Fischer's Exact and Student's T-test. Survival was analyzed via Kaplan-Meier and log-rank test.

RESULTS

Eighty-nine patients were available for analysis, 37 of which met inclusion criteria. Intraoperative death occurred in 3 patients (8.1%) and 1 patient (2.7%) was intraoperatively converted to an open repair. Thirty-day and 1-year survival were 97% and 91%, respectively. The reintervention rate was 30% (n = 10), occurring at a median of 200 days (18-2053 days) after the index operation. All patients requiring reintervention met hostile neck criteria (p = .002) and had a statistically higher number of hostile neck criteria (1.80 vs 0.87, p = .03). Thirty percent (n = 3) of patients that received a reintervention had neck diameter greater than 3 cm, compared to zero patients in the non-reintervention group (p = .022). Proximal reinterventions (n = 5) had statistically higher neck diameters and neck angle compared to the non-reintervention group.

CONCLUSION

Infrarenal rEVAR is effective at preventing acute mortality despite specific anatomic considerations that may contribute to the higher reintervention rates, and therefore those parameters ought to be considered when following patients in the post-intervention period.

The Challenge of Treating Abdominal Aortic Aneurysms with Hostile Neck Anatomy: An Overview

Hostile aortic neck anatomy challenges the outcomes of endovascular abdominal aortic aneurysm repair (EVAR). Besides reverting to open surgical repair (OSR), thoughtful endograft selection and a number of advanced endovascular techniques have been suggested as potential solutions for preventing proximal seal zone complications, improving EVAR durability, and preventing aneurysm-related death. Each technique is associated with advantages and limitations and there has not been a credible direct comparison amongst them in the form of a well-designed prospective trial. The not infrequent presence of multiple hostile anatomic characteristics further complicates decision making and challenges the surgeon's skills. This paper serves as an overview of hostile neck anatomy and its implications on EVAR. We provide a concise literature review with the purpose of outlining the treatment modalities and outcomes in this patient population.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL IMPACT

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

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.

The Correlation of Aortic Neck Angle and Length in Abdominal Aortic Aneurysm with Severe Neck Angulation for Prediction of Intraoperative Neck Complications and Postoperative Outcomes after Endovascular Aneurysm Repair

OBJECTIVES

Endovascular aneurysm repair (EVAR) in a hostile neck has been associated with adverse outcomes. We aimed to determine the association of infrarenal aortic neck angle and length and establish an optimal cutoff value to predict intraoperative neck complications and postoperative outcomes.

METHODS

This was a retrospective review of patients with an intact infrarenal abdominal aortic aneurysm (AAA) with severe neck angulation (>60 degrees) who underwent EVAR from October 2010 to October 2018. Demographic data, aneurysm morphology, and operative details were collected. The ratio of neck angle and length was calculated as the optimal cutoff value of the aortic neck angle-length index. The patients were categorized into two distinct groups using latent profile analysis, a statistical technique employed to identify concealed subgroups within a larger population by examining a predetermined set of variables. Intraoperative neck complications, adjunct neck procedures, and early and late outcomes were compared.

RESULTS

115 patients were included. Group 1 (G1) had 95 patients with an aortic neck angle-length index ≤ 4.8, and Group 2 (G2) had 20 patients with an aortic neck angle-length index > 4.8. Demographic data and aneurysm morphology were not significantly different between groups except for neck length (p < 0.001). G2 had more intraoperative neck complications than G1 (21.1% vs. 55%, p = 0.005). Adjunctive neck procedures were more common in G2 (18.9% vs. 60%, p < 0.001). The thirty-day mortality rate was not statistically different. G1 patients had a 5-year proximal neck re-intervention-free rate comparable to G2 patients (93.7% G1 vs. 87.5% G2, p = 0.785). The 5-year overall survival rate was not statistically different (59.9% G1 vs. 69.2% G2, p = 0.891).

CONCLUSIONS

Patients with an aortic neck angle-length index > 4.8 are at greater risk of intraoperative neck complications and adjunctive neck procedures than patients with an aortic neck angle-length index ≤ 4.8. The 5-year proximal neck re-intervention-free rate and the 5-year survival rate were not statistically different. Based on our findings, this study suggests that the aortic neck angle-length index is a reliable predictor of intraoperative neck complications during EVAR in AAA with severe neck angulation.

Long-term outcomes of the Endurant endograft in patients undergoing endovascular abdominal aortic aneurysm repair

OBJECTIVE/BACKGROUND

To investigate the long-term outcomes after endovascular aneurysm repair (EVAR) in a real-world setting using the Endurant endograft (EG).

METHODS

184 EVAR candidates treated with the Endurant family EGs in a single vascular center were prospectively enrolled from January 2009 to December 2016. Kaplan-Meir estimates of long-term standardized primary and secondary outcome measures were performed. Per protocol, subgroup comparison analysis was performed in three groups: patients treated within instructions for use (in-IFU) vs patients treated outside IFU (outside-IFU), EVAR in patients receiving the Endurant proximal diameter 32 or 36 mm EG vs those receiving the <32 mm diameter EG and EVAR with various Endurant EG versions.

RESULTS

The mean follow-up was 75.09 ± 37.9 months (range: 4.1-172 months). The median age of the patients was 72.96 ± 7.03 years (range: 55-88 years). A total of 177 patients were male (96.2%). Compliance with IFU was followed in 107 patients (58.2%). Overall survival was 69.5% and 48% at 5 and 8 years, respectively. Of the 102 all-cause deaths, 7 (6.9%) were aneurysm related. Six of these postimplant deaths occurred in patients presented with aneurysm rupture from type Ia or/and type Ib endoleak. At 5, 8, and 10 years of observation, freedom from aneurysm rupture, open surgical conversion, type I/III endoleak, any type of endoleak, aneurysm-related secondary intervention probabilities, and neck-related events were as follows: 98.1%, 95%, and 89.4%; 95.1%, 91.2%, and 85.7%; 93.6%, 87.3%, and 83.9%; 83.4%, 74%, and 70.9%; 89.8%, 76.7%, and 72%; and 96.3%, 90%, and 87.6%, respectively. Corresponding clinical success was 90%, 77.4%, and 68.4%, respectively. Patients treated outside-IFU had significantly higher risk of aneurysm rupture, open surgical conversion probability, occurrence of type I/III endoleak, and chance of reinterventions and lower clinical success probabilities compared with the in-IFU counterparts at 5 and 8 years. This statistical difference remained when type Ia endoleak or endoleak of any type was considered independently. In addition, it was stronger in patients having extreme anatomic boundaries (>1 hostile anatomic condition), when aneurysm-related death, aneurysm rupture, and clinical success at 5 years were considered. Overall proximal migration and limb occlusion were recorded in 1.1% and 4.9% of the patients, respectively. Overall reintervention rate was 17.4%. An increase in aneurysm sac diameter was observed in 12.5% of patients and was not related to IFU status. The Endurant version or the proximal EG diameter had no significant association with the chance of any complication or adverse event.

CONCLUSIONS

The data confirmed the durability of the Endurant EG, achieving promising long-term outcomes in a real-world setting. However, its positive performance must be interpreted with caution in patients treated off-label especially those with extreme anatomic boundaries. In this cohort, some of EVAR advantages might be lost in the late future. Further similar studies are warranted.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL IMPACT

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

Infrarenal Abdominal Aortic Aneurysm

Abdominal aortic aneurysms are found in up to 6% of men and 1.7% of women over the age of 65 years and are usually asymptomatic. The natural history of aortic aneurysms is continued dilation leading to rupture, which is associated with an overall 80% mortality. Of the patients with ruptured aneurysms that undergo intervention, half will not survive their hospitalization. Reduction in aneurysm mortality is therefore achieved by prophylactic repair during the asymptomatic period. On a population-based level, this is supported by abdominal aortic aneurysm screening programs. Approximately 60% of abdominal aortic aneurysms are confined to the infrarenal portion of the aorta and are amenable to repair with off-the-shelf endovascular devices. Endovascular techniques have now replaced open surgery as the primary modality for aneurysm repair.

Technical tips and clinical experience with the Cook Triple inner arch branch stent-graft

Open surgical repair remains the gold standard for treatment for aortic arch diseases, but these operations can be associated with wide heterogeneity in outcomes and significant morbidity and mortality, particularly in elderly patients with severe comorbidities or those who had prior arch procedures via median sternotomy. Endovascular repair has been introduced as a less invasive alternative to reduce morbidity and mortality associated with open surgical repair. The technique evolved with new device designs using up to three inner branches for incorporation of the supra-aortic trunks. This manuscript summarizes technical tips and clinical experience with the triple inner arch branch stent graft for total endovascular repair of aortic arch pathologies.

EndoSuture aneurysm repair versus fenestrated aneurysm repair in patients with short neck abdominal aortic aneurysm

OBJECTIVE

The aim of this study was to compare midterm results of EndoAnchors in EndoSuture aneurysm repair (ESAR) versus fenestrated endovascular aneurysm repair (FEVAR) in short neck abdominal aortic aneurysm (AAA).

METHODS

All patients who underwent an ESAR procedure for a short neck AAA at our center between September 2017 and May 2020 were considered for analysis. To form the control group, preoperative computed tomography angiography of patients who underwent FEVAR for juxtarenal AAA between April 2012 and May 2020 were reviewed and patients who met short neck criteria selected. A propensity-matched score on neck length and neck diameter was calculated, resulting in 18 matched pairs. AAA shrinkage, type Ia endoleaks (EL), AAA-related reinterventions, and AAA-related deaths were compared.

RESULTS

The median AAA diameter was 54 mm (interquartile range [IQR], 52-61 mm) versus 58 mm (IQR, 53-63 mm) with a median neck length of 8 mm (IQR, 6-12 mm) vs 10 mm (IQR, 6-13 mm) in ESAR and FEVAR patients, respectively. Technical success was 100% in both groups. Procedural success was 94% in the ESAR group versus 100% in the FEVAR group. The median procedure duration was 138 mm (IQR, 113-182 mm) vs 240 mm (IQR, 199-293 mm) ( P < .001) and the median length of stay was 2 days (IQR, 2-3 days) vs 7 days (IQR, 6-7 days) (P < .001) in ESAR and FEVAR patients, respectively. No major hospital complications were observed in ESAR patients compared with two in FEVAR patients (11%) with one transient acute kidney injury and one transient paraplegia. The median follow-up was 23 months (IQR, 19-33 months) vs 36 months (IQR, 22-57 months) with 67% versus 61% AAA shrinkage in the ESAR and FEVAR groups, respectively (P = .73). No type Ia EL, proximal neck-related reinterventions, or AAA-related deaths were observed in either group. No AAA-related reintervention was observed in the ESAR group versus three reinterventions in the FEVAR group (P = .23).

CONCLUSIONS

ESAR seems to be a safe technique with no major postoperative complications or reinterventions observed during follow-up. It seems to offer similar midterm results as FEVAR in terms of type Ia EL, aneurysm shrinkage, and aneurysm-related mortality. ESAR seems to be a good off-the-shelf alternative to FEVAR in case of technical constraints.

Use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers increases the risk of postoperative acute kidney injury after elective endovascular abdominal aortic aneurysm repair

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) is the major treatment for abdominal aortic aneurysm (AAA); however, EVAR still carries a considerable risk of acute kidney injury (AKI). The present study aimed to investigate the risk factors for AKI after elective EVAR procedures.

METHODS

This was a retrospective observational study. Eligible patients who underwent EVAR from September 2011 to March 2019 in West China Hospital were included. The primary outcome was the occurrence of AKI within two days after EVAR, which was defined by the Kidney Disease Improving Global Outcomes Clinical Practice Guideline. Demographics, comorbidities, medications, laboratory tests, anatomical parameters of AAA, and relative operative details were collected as variables. Univariable and multivariable logistic regression analyses were applied to identify the risk factors among variables, and covariate interactions were further assessed.

RESULTS

A total of 679 eligible patients were included. The incidence of postoperative AKI was 8.2% (56/679) in the whole cohort, and it was associated with a lower 5-year survival rate (63.5% vs . 80.9%; χ 2  = 4.10; P  = 0.043). The multivariable logistic regression showed that chronic kidney disease (OR, 5.06; 95% CI: 1.43-17.95; P  = 0.012), angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) (OR, 2.60; 95% CI: 1.17-5.76; P  = 0.019), and short neck (OR, 2.85; 95% CI: 1.08-7.52; P  = 0.035) were independent risk factors for postoperative AKI. In the covariate interaction analysis, the effect of ACEIs/ARBs use on postoperative AKI was similar across all subgroups ( P  > 0.05), thereby suggesting a robust effect of ACEIs/ARBs use in all patients undergoing elective endovascular abdominal aortic aneurysm repair.

CONCLUSIONS

Postoperative AKI was associated with lower survival rate, and the use of ACEIs/ARBs was the only adjustable independent risk factor. Clinicians should consider withdrawing ACEIs/ARBs in high-risk patients undergoing elective endovascular abdominal aortic aneurysm repair to prevent postoperative AKI.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Fenestrierte und verzweigte endovaskuläre Aortenprothesen

Hintergrund

Komplexe abdominelle aortale Pathologien, welche die Abgänge der Viszeralarterien miterfassen und bei denen kein adäquater proximaler Hals gegeben ist, können heute mittels fortgeschrittener FEVAR/BEVAR-Technik („fenestrated/branched endovascular aneurysm repair“) mit ähnlicher Sicherheit und vergleichbaren Erfolgsraten behandelt werden wie infrarenale Pathologien mit konventionellem EVAR.

Methodische Innovationen und Probleme

Zur Versorgung der Viszeralarterien können Fenestrierungen (bei Abgang der Viszeralarterie aus der nichtdilatierten Aorta) oder Verzweigungen (bei Abgang aus der dilatierten Aorta) verwendet werden. Beide Arten von Öffnungen werden mit Verbindungsstentgrafts (VSG) zu den Viszeralarterien abgedichtet. Mehrere Hersteller bieten fenestrierte oder verzweigte Endoprothesen an, wobei diese nur in Einzelfällen CE-zertifiziert und überwiegend in Europa als individuelle Sonderanfertigungen patientenbezogen erhältlich sind. Dies setzt eine entsprechende Lieferzeit voraus, was die Behandlung akuter Patienten mit solchen Prothesen unmöglich macht. Es liegen allerdings zwei Produkte von vierfach verzweigten Endoprothesen vor, die einen größeren Bereich der anatomischen Gegebenheiten bei thorakoabdominellen Aneurysmen auch im Akutfall abdecken und behandelbar machen. Sämtliche FEVAR- und BEVAR-Hauptkörper benötigen VSG, die durchgehend von Fremdherstellern stammen und von denen gegenwärtig noch kein einziges Produkt für diese Anwendung zertifiziert ist.

Empfehlungen

Da Probleme an Verbindungsstentgrafts eine wesentliche Ursache für Reinterventionen sind, sollte in der Nachsorge Knickbildungen und Brüchen an diesen Verbindungsstents besonderes Augenmerk geschenkt und von der Verwendung einschichtiger Designs beim BEVAR abgesehen werden.

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

DEFINITION

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

EFFECTS ON OUTCOME

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

TREATMENT OPTIONS

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

Contemporary Indications for Open Abdominal Aortic Aneurysm Repair in the Endovascular Era

INTRODUCTION AND OBJECTIVES

Despite the emergence of endovascular aneurysm repair (EVAR) as the most common approach to abdominal aortic aneurysm repair, open aneurysm repair (OAR) remains an important option. This study seeks to define the indications for OAR in the EVAR era and how these indications effect outcomes.

METHODS

A retrospective cohort study was performed of all OAR at a single institution from 2004 to 2019. Pre-operative computed tomography scans and operative records were assessed to determine the indication for OAR. These reasons were categorized into anatomical contraindications; systemic factors (connective tissue disorders, contraindication to contrast dye); and patient/surgeon preference (patients who were candidates for both EVAR and OAR). Perioperative and long-term outcomes were compared between the groups.

RESULTS

370 patients were included in the analysis; 71.6% (265/370) had at least one anatomic contraindication to EVAR; 36% had two or more contraindications. The most common anatomic contraindications were short aortic neck length (51.6%), inadequate distal seal zone (19.2%), and inadequate access vessels (15.7%). The major perioperative complication rate was 18.1% and the 30-day mortality was 3.0%. No single anatomic factor was identified as a predictor of perioperative complications. Sixty-one patients (16.5%) had OAR based on patient/surgeon preference; these patients were younger; had lower incidences of coronary artery disease and chronic obstructive pulmonary disease; and they were less likely to require suprarenal cross clamping compared with patients who had anatomic and/or systemic contraindications to EVAR. The patient/surgeon preference group had a lower incidence of perioperative major complications (8.2% versus 20.1%, p=0.034), shorter length of stay (6 versus 8 days, p<0.001) and zero 30-day mortalities. The multivariable adjusted risk for 15-year mortality was lower for patient/surgeon preference patients (adjusted hazard ratio 0.44 [95% confidence interval 0.24-0.80], p=0.007) compared to those anatomic/systemic contraindications.

CONCLUSIONS

Within a population of patients who did not meet instruction for use (IFU) criteria for EVAR, no single anatomic contraindication was a marker for worse outcomes with OAR. Patients who were candidates for both aortic repair approaches but elected to have open surgical repair due to patient/surgeon preference have very low 30-day mortality and morbidity, and superior long-term survival rates compared with those patients who had OAR due to anatomic and/or systemic contraindications to EVAR.

Hybrid Approach in Acute and Chronic Aortic Disease

The management of patients with aortic disease that involves the ascending aorta, the aortic arch, and the descending aorta represent a surgical challenge. Open surgical repair remains the gold standard for aortic arch pathologies. However, this operation requires a cardiopulmonary bypass and a period of profound hypothermia and circulatory arrest, which carries a substantial rate of mortality and morbidity. For these reasons, hybrid arch repair that involves a combination of open surgery with endovascular aortic stent graft placement has been introduced as a therapeutic alternative for those patients deemed unfit for open surgical procedures. Hybrid repair requires varying degrees of invasiveness and can be performed as a single-stage procedure or as a two-stage procedure. The choice of the technique is multifactorial, depending on the characteristics of the diseased arch with regard to position of the stent graft proximal landing zone, patient fitness and comorbid status, as well as surgical expertise and hospital facilities. Among the evolving hybrid procedures is the so-called “frozen” or stented elephant trunk technique. Adapted from the classical elephant trunk technique, this approach facilitates the repair of a concomitant aortic arch and proximal descending aortic aneurysms in a single stage under circulatory arrest. This technique is increasingly being used to treat extensive thoracic aortic disease and has shown promising results.

Postoperative imaging follow-up at 2 years as a predictor of long-term outcomes after endovascular aneurysm repair

OBJECTIVE

Lifelong imaging follow-up remains the reference standard after endovascular aneurysm repair (EVAR). Because the number of EVARs has been increasing, an individually optimized follow-up protocol is desirable. The aim of the present study was to investigate the possibility of creating such a protocol by evaluating patients' follow-up images and to compare the findings with their freedom from reintervention and abdominal aortic aneurysm (AAA) rupture.

METHODS

From 2000 to 2010, 282 patients with an AAA had undergone elective EVAR with the Zenith stent-graft. The patients were followed up annually until the end of 2019. The patients were categorized into two groups according to the presence of any endoleak or sac shrinkage at 2 years. Group A included those with no detectable endoleak plus aneurysm sac shrinkage of ≥5 mm (n = 137; 63%), and group B included those with any type of endoleak and/or no significant aneurysm sac shrinkage (<5 mm; n = 82; 37%).

RESULTS

The mean follow-up was 83 months (range, 0-229 months), and the overall survival at 2 years was 84% (n = 237). No significant difference was found in overall survival between groups A and B (P = .73). However, a significant difference was found in freedom from AAA rupture at 12 years, favoring group A (group A, 100%; group B, 91%; P = .002). Furthermore, in group A, the freedom from reintervention was 95% at 12 years compared with only 31% in group B (P < .001). The sensitivity of the categorization was 89% and the specificity was 74% for the finding of a complication requiring a reintervention during long-term follow-up.

CONCLUSIONS

Patients without an endoleak and a reduction of ≥5 mm in aneurysm size at 2 years had significantly fewer late reinterventions and ruptures during long-term follow-up compared with their counterparts using the Zenith stent-graft (Cook Medical, Bloomington, Ind). This finding suggests that, for these patients, the follow-up interval can be personalized and safely extended after 2 years.

Use of Gore C-TAG with active control to treat a complex infrarenal abdominal aortic aneurysm

Complex abdominal aortic aneurysms (AAAs) can preclude the use of endovascular aortic repair. In patients unable to undergo open surgical repair (OSR), the use of endografts outside the instructions for use might be the only option. We present the case of a woman with a highly angulated infrarenal AAA neck who was unsuitable for OSR and was successfully treated using a Gore C-TAG conformable thoracic stent graft (W.L. Gore and Associates, Inc, Flagstaff, Ariz) with active control, Medtronic Heli-FX EndoAnchors (Medtronic Vascular, Minneapolis, Minn), and a bifurcated Gore Excluder endoprosthesis W.L. Gore and Associates). The repair was successful without evidence of an endoleak. Using a thoracic endograft outside of the instructions for use to treat infrarenal AAAs might be feasible for patients unable to undergo OSR.

Multicenter Mid-term Results After Endovascular Aortic Aneurysm Repair with the Incraft® Device

OBJECTIVES

Durability after endovascular aortic aneurysm repair (EVAR) is considered an ongoing topic of investigation and was always a point of concern with smaller profile devices. Recently released five-year clinical trial results using the Incraft® ultralow profile device are encouraging. However, additional real-life experience will need to assist these initial findings. Herein, we investigated the outcomes after EVAR, in real world practice using the Incraft® endograft (EG).

MATERIAL AND METHODS

Seventy-seven patients with infrarenal abdominal aortic aneurysms (AAA) ≥50 mm in diameter treated with the Incraft® device in three vascular centers were enrolled from November 2015 to July 2018. Follow-up was completed in August 2020. Selection of EVAR using the Incraft® device was individualized according to aorto-iliac morphologic features, comorbidities, history of previous abdominal surgery and preference of the patient. At the early phase of the study, we specifically opted for preferential use of this low profile EG mainly in cases of small and tortuous iliac vessels (more challenging access routes). At later stages, it was used according to surgeon preference and not specifically in complex anatomies (real-world conditions). End-points included technical success, perioperative complications, 30-day survival, endoleg patency, presence of endoleaks, sac enlargement >5 mm and clinical success.

RESULTS

The primary technical success rate was 97.4% before the addition of an aortic cuff and iliac extension for a type Ia and type Ib endoleak respectively, and the repair of a maldeployment iliac component (primary-assisted and secondary technical success, 100%). Intraoperative small type II endoleaks (visible in final angiogram) were noted in 19 patients (24.7%). There were no intraoperative deaths from AAA rupture, primary conversions or conversions to aortounilateral grafts. Two complications occurred, necessitating hybrid techniques for repair (replaced of a dislodged endoleg and distal external iliac artery hemostasis). No deaths were reported within 30 days. Occlusion of an endoleg, was observed in two patients, 6 and 14 months respectively after implantation (2.6%), and were treated by femoral-femoral PTFE bypass after unsuccessful endovascular recanalization. The latter required open conversion, 3 mo later, to repair compromised flow to the inflow iliac axis. Three patients (3.9%) experienced sac enlargement >5 mm in diameter compared with the 1-month CT scan. All of these had type II endoleaks and two received embolization procedures. Eleven patients died from causes unrelated to AAA repair. Clinical success was 97.3%, 92.8% and 89.4% through 1, 2 and 3 years respectively.

CONCLUSIONS

EVAR with the Incraft® device might be considered a reliable option in real-world conditions and not specifically only in complex iliac anatomies.

A penalized spline fitting method to optimize geometric parameters of arterial centerlines extracted from medical images

In order to grasp the spatial and temporal evolution of vascular geometry, three-dimensional (3D) arterial bending structure and geometrical changes of arteries and stent grafts (SG) must be quantified using geometrical parameters such as curvature and torsion along the vasculature centerlines extracted from medical images. Here, we develop a robust method for constructing smooth centerlines based on a spline fitting method (SFM) such that the optimized geometric parameters of curvature and torsion can be obtained independently of digitization noise in the images. Conventional SFM consists of the 3rd degree spline basis function and 2nd derivative penalty term. In contrast, the present SFM uses the 5th degree spline basis function and 3rd and 4th derivative penalty terms, the coefficients of which are derived by the Akaike information criterion. The results show that the developed SFM can reduce the errors of curvature and torsion compared to conventional SFM. We then apply the present SFM to the centerline of the SG in an abdominal aortic aneurysm (AAA), and those of bilateral internal carotid arteries (ICA) in 6 cases: 3 cases with aneurysms and 3 cases without any aneurysm. The SG centerlines were obtained from temporal medical images at three scan times. The strong peak of the curvature could be clearly observed in the distal area of the SG, the inversion of the torsion at 0 months in the middle area of SG disappeared over time, and the torsions around the SG bifurcation at the three time periods were inverted. The curvature-torsion graphs along the ICA centerlines superimposing five aneurysmal positions were useful for investigating the relationship between arterial bending structure and aneurysmal positions. Both ICAs had curvature peak values higher than 0.4 within the ICA syphons. The ICA torsion graphs indicated that left and right ICA tended to be a right- and left-handed helix, respectively. In the left ICA syphon, the biggest aneurysm could be observed downstream of the salient torsion inversion. All aneurysms for 3 cases were positioned at the downstream of the inverted torsion.

Suitability of the Aortic Neck Anatomy for Endovascular Aneurysm Repair in Korean Patients with Abdominal Aortic Aneurysm

Purpose

To evaluate the aortic neck anatomy in Korean patients with abdominal aortic aneurysms (AAAs).

Materials and Methods

We examined computed tomography scans of 343 patients with AAAs (≥5.5 cm for men or ≥5 cm for women) between 2009 and 2018. Eligibility of neck anatomy for endovascular aneurysm repair (EVAR) was assessed with the standard instructions for use (IFU) (length ≥15 mm, suprarenal angulation (SRA) ≤45°, infrarenal angulation (IRA) ≤60°, and diameter 18-32 mm) and the extended IFU (length ≥10 mm, SRA ≤60°, IRA ≤75°, and diameter 17-32 mm).

Results

There were 71 women (20.7%), and 61 patients (17.8%) with rupture. Women had smaller neck diameters (21.3 vs. 23.4 mm, P<0.001 for proximal neck; 22.2 vs. 24.5 mm, P<0.001 for distal neck), and higher angulations (51.5° vs. 37.8°, P<0.001 for SRA; 77.7° vs. 57.0°, P<0.001 for IRA) than men. However, the neck length was not significantly different. Patients with ruptured AAAs had shorter neck lengths (21.0 vs. 26.8 mm, P=0.005) than those with intact AAAs. However, the neck diameters and angulations were not significantly different. EVAR eligibility for standard and extended IFUs was found in 37.5% and 55.1% of men, and 11.3% and 25.4% of women (P<0.001 for both IFUs); neck anatomy was eligible in 34.0% of intact AAAs and 23.0% of ruptured AAAs (P=0.098).

Conclusion

A significant proportion of the Korean patients did not meet the IFU for EVAR, mainly due to the angulated neck. Women, and patients with ruptured AAAs, were less likely to meet the IFU criteria.

Anatomical aspects and feasibility of endovascular repair for chronic post-dissection arch and thoracoabdominal aortic aneurysms

Aortic dissection is a complex pathology that carries significant morbidity and mortality if not treated in a timely fashion. While the open repair remains the gold standard treatment for patients with acute type A dissection, ascending aortic replacement is associated with high incidence of arch and descending thoracic aorta residual false lumen patency and aneurysmal degeneration. Multiple approaches have been used over the decades to address aneurysmal degeneration in the arch and thoracoabdominal aorta. This article summarizes anatomical requirements for total endovascular repair of aortic arch and TAAAs using fenestrated and branched endografts.

Outcomes of Endovascular Repair for Abdominal Aortic Aneurysms: A Nationwide Survey in Japan

OBJECTIVE

To analyze data on patients treated with a bifurcated stent graft for abdominal aortic aneurysm (AAA).

BACKGROUND

The Japan Committee for Stentgraft Management (JACSM) was established in 2007 to manage the safety of endovascular aortic aneurysm repair (EVAR) in Japan. The JACSM registry includes detailed anatomical and clinical data of all patients who undergo stent graft insertion in Japan.

METHODS

Among 51,380 patients treated with bifurcated stent graft for AAA, we identified 38,008 eligible patients (excluding those with rupture or insufficient data). The analyzed factors included age, sex, comorbidities, AAA pathology and etiology, aneurysm and neck diameters, 7 anti-instructions for use (IFU) factors, and endoleaks at hospital discharge. The endpoints were death, adverse events, sac dilatation (≥5 mm), and reintervention.

RESULTS

The rates of intraoperative and in-hospital mortality were 0.08% and 1.07%, respectively. Infectious aneurysm and pseudo-aneurysm were associated with overall survival and reintervention. Older age, large aneurysm diameter, and all types of persistent endoleaks were strong predictors of adverse events, sac dilatation, and reintervention. Comorbid cerebrovascular disease, renal dysfunction, and respiratory disorders were also risk factors. In total, 47.6% of patients violated the IFU; among the anti-IFU factors assessed, poor access and severe neck calcification were strong risk factors for mortality, reintervention, and adverse events. The sac dilatation rate at 5 years was 23.3%.

CONCLUSIONS

Although the analysis included EVAR with poor anatomy, the perioperative mortality rate was acceptable compared with that in previous large population studies.

Fenestrated/Branched Endovascular Aortic Aneurysm Repair Using a Supraceliac Aortic Proximal Seal Zone Versus an Infraceliac Aortic Proximal Seal Zone

BACKGROUND

Fenestrated/branched endovascular aneurysm repair (F/B-EVAR) achieves more extensive proximal seal than conventional infrarenal devices, thereby increasing aneurysm exclusion durability. Optimal seal zone length remains undefined. We assessed relative risks and benefits of extending the proximal seal above the celiac artery.

METHODS

The prospective database of all complex endovascular aortic aneurysm repairs at a single institution (institutional review board-approved, physician-sponsored investigational device exemption trial, 10/2010-6/2017) was used to classify repairs according to the number of target visceral-renal arteries incorporated: 4-vessel versus <4-vessel. Comparisons of aneurysm characteristics, perioperative details, and postoperative complications were performed, stratified by repair type. One-year survival, target artery patency, freedom from type 1 or 3 endoleak, and freedom from reintervention were estimated with Kaplan-Meier analysis.

RESULTS

Among 175 F/B-EVARs, 38% (n = 67) were 4-vessel and 62% (n = 108) were <4-vessel. Intraoperatively, there was no difference in mean contrast use (76 mL vs. 74 mL, P = non significant [NS]) or dose area product (63,428 mGy cm² vs. 96,015 mGy cm²), but there was increased median procedure time (4.8 hr, interquartile range [IQR] = 4.1-5.8 versus 3.6 hr, IQR = 2.9-4.1, P < 0.0001) and mean operating room direct costs ($52,532, standard deviation [SD] = 18,640 versus $40,128, SD = 15,135, P < 0.0001) in 4-vessel repairs. There were no differences in mortality (1.9% vs. 4.5%), paraparesis (0% vs. 3.0%), or paralysis (0.9% vs. 0%), all P = NS. There were no differences in one-year survival, target artery patency, or freedom from reintervention. There was a lower 1-year freedom from type 1 or 3 endoleak with 4-vessel repairs (82% vs. 94%, log-rank P = 0.02), driven by an increased rate of type 3 endoleaks. Endoleak resolution after treatment was equivalent in both groups (4-vessel, 10 of 12, 83% resolved; <4-vessel, 7 of 7, 100% resolved, P = NS).

CONCLUSIONS

With F/B-EVAR, utilization of a supraceliac seal zone, compared with an infraceliac seal zone, is associated with statistical differences in operative characteristics/resource utilization, but with negligible clinical significance. Further innovation to eliminate type 3 endoleaks at fenestrations/branches remains an unmet need. To achieve adequate F/B-EVAR proximal seal zone length, one should have a low threshold to incorporate the celiac artery.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) is less invasive than open surgery, but may be associated with important complications. Patients receiving EVAR require long-term surveillance to detect abnormalities and direct treatments. Computed tomography angiography (CTA) has been the most common imaging modality adopted for EVAR surveillance, but it is associated with repeated radiation exposure and the risk of contrast-related nephropathy. Colour duplex ultrasound (CDU) and, more recently, contrast-enhanced ultrasound (CEU) have been suggested as possible, safer, alternatives to CTA.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of imaging strategies, using either CDU or CEU alone or in conjunction with plain radiography, compared with CTA for EVAR surveillance.

DATA SOURCES

Major electronic databases were searched, including MEDLINE, EMBASE, Science Citation Index, Scopus' Articles-in-Press, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database from 1996 onwards. We also searched for relevant ongoing studies and conference proceedings. The final searches were undertaken in September 2016.

METHODS

We conducted a systematic review of randomised controlled trials and cohort studies of patients with AAAs who were receiving surveillance using CTA, CDU and CEU with or without plain radiography. Three reviewers were involved in the study selection, data extraction and risk-of-bias assessment. We developed a Markov model based on five surveillance strategies: (1) annual CTA; (2) annual CDU; (3) annual CEU; (4) CDU together with CTA at 1 year, followed by CDU on an annual basis; and (5) CEU together with CTA at 1 year, followed by CEU on an annual basis. All of these strategies also considered plain radiography on an annual basis.

RESULTS

We identified two non-randomised comparative studies and 25 cohort studies of interventions, and nine systematic reviews of diagnostic accuracy. Overall, the proportion of patients who required reintervention ranged from 1.1% (mean follow-up of 24 months) to 23.8% (mean follow-up of 32 months). Reintervention was mainly required for patients with thrombosis and types I-III endoleaks. All-cause mortality ranged from 2.7% (mean follow-up of 24 months) to 42% (mean follow-up of 54.8 months). Aneurysm-related mortality occurred in < 1% of the participants. Strategies based on early and mid-term CTA and/or CDU and long-term CDU surveillance were broadly comparable with those based on a combination of CTA and CDU throughout the follow-up period in terms of clinical complications, reinterventions and mortality. The economic evaluation showed that a CDU-based strategy generated lower expected costs and higher quality-adjusted life-year (QALYs) than a CTA-based strategy and has a 63% probability of being cost-effective at a £30,000 willingness-to-pay-per-QALY threshold. A CEU-based strategy generated more QALYs, but at higher costs, and became cost-effective only for high-risk patient groups.

LIMITATIONS

Most studies were rated as being at a high or moderate risk of bias. No studies compared CDU with CEU. Substantial clinical heterogeneity precluded a formal synthesis of results. The economic model was hindered by a lack of suitable data.

CONCLUSIONS

Current surveillance practice is very heterogeneous. CDU may be a safe and cost-effective alternative to CTA, with CTA being reserved for abnormal/inconclusive CDU cases.

FUTURE WORK

Research is needed to validate the safety of modified, more-targeted surveillance protocols based on the use of CDU and CEU. The role of radiography for surveillance after EVAR requires clarification.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016036475.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The use of EndoAnchors in endovascular repair of abdominal aortic aneurysms with challenging proximal neck: Single-centre experience

Objectives

The aim of this study was to present a single-centre experience with EndoAnchors in patients who underwent endovascular repair for abdominal aortic aneurysms with challenging proximal neck, both in the prevention and treatment of endograft migration and type Ia endoleaks.

Methods

We retrospectively analysed 17 consecutive patients treated with EndoAnchors between June 2015 and May 2018 at our institution. EndoAnchors were applied during the initial endovascular aneurysm repair procedure (primary implant) to prevent proximal neck complications in difficult anatomies (nine patients), and in the follow-up after aneurysm exclusion (secondary implant) to correct type Ia endoleak and/or stent-graft migration (eight patients).

Results

Mean time for anchors implant was 23 min (range 12–41), with a mean of 5 EndoAnchors deployed per patient. Six patients in the secondary implant group required a proximal cuff due to stent-graft migration ≥10 mm. Technical success was achieved in all cases, with no complications related to deployment of the anchors. At a median follow-up of 13 months (range 4–39, interquartile range 9–20), there were no aneurysm-related deaths or aneurysm ruptures, and all patients were free from reinterventions. CT-scan surveillance showed no evidence of type Ia endoleak, anchors dislodgement or stent-graft migration, with a mean reduction of aneurysm diameter of 0.4 mm (range 0–19); there was no sac growth or aortic neck enlargement in any case.

Conclusions

EndoAnchors can be safely used in the prevention and treatment of type Ia endoleaks in patients with challenging aortic necks, with good results in terms of sac exclusion and diameter reduction in the mid-term follow-up.

Advanced endografting techniques: snorkels, chimneys, periscopes, fenestrations, and branched endografts

The anatomy of aortic aneurysms from the proximal neck to the access vessels may create technical challenges for endovascular repair. Upwards of 30% of patients with abdominal aortic aneurysms (AAA) have unsuitable proximal neck morphology for endovascular repair. Anatomies considered unsuitable for conventional infrarenal stent grafting include short or absent necks, angulated necks, conical necks, or large necks exceeding size availability for current stent grafts. A number of advanced endovascular techniques and devices have been developed to circumvent these challenges, each with unique advantages and disadvantages. These include snorkeling procedures such as chimneys, periscopes, and sandwich techniques; "homemade" or "back-table" fenestrated endografts as well as manufactured, customized fenestrated endografts; and more recently, physician modified branched devices. Furthermore, new devices in the pipeline under investigation, such as "off-the-shelf" fenestrated stent grafts, branched stent grafts, lower profile devices, and novel sealing designs, have the potential of solving many of the aforementioned problems. The treatment of aortic aneurysms continues to evolve, further expanding the population of patients that can be treated with an endovascular approach. As the technology grows so do the number of challenging aortic anatomies that endovascular specialists take on, further pushing the envelope in the arena of aortic repair.

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.

Single-center experience with complex abdominal aortic aneurysms treated by open or endovascular repair using fenestrated/branched endografts

OBJECTIVE

The objective of this study was to evaluate outcomes of patients with complex abdominal aortic aneurysms (cAAAs) treated with open repair (OR) or fenestrated/branched endovascular aneurysm repair (F/B-EVAR) from a single center.

METHODS

A retrospective analysis of consecutive patients with cAAAs treated electively by OR or F/B-EVAR between January 2010 and February 2017 was conducted. Demographics of the patients, cardiovascular risk factors, procedure time, number of vessels incorporated, radiation dose, estimated blood loss, intensive care unit (ICU) length of stay (LOS), and hospital LOS were recorded. End points included target vessel patency, aneurysm rupture, freedom from reintervention, and major adverse events (MAEs).

RESULTS

During this period, 153 patients (OR, 69; F/B-EVAR, 84) underwent repair of cAAA. The majority were male (OR, 55; F/B-EVAR, 64), with a mean age of 75.8 ± 7.6 years (F/B-EVAR) and 71.2 ± 7.9 years (OR). Patients in the F/B-EVAR group were more likely to be American Society of Anesthesiologists class 3 and 4 (60% vs 0%; P < .001) and had a higher median Society for Vascular Surgery/American Association for Vascular Surgery comorbidity severity score (15 vs 7; P < .001). A total of 235 vessels were targeted in the F/B-EVAR group, with a technical success of 97.6%. Thirty-one patients in the OR group required concomitant renal artery revascularization. Transfusion requirements (100% vs 1.2%), MAEs (40.6% vs 13.1%), procedure length (304 minutes vs 140 minutes), estimated blood loss (2246 mL vs 165 mL), ICU LOS (3 days vs 1 day), and hospital LOS (7 days vs 2 days) were higher (P < .001) in the OR group compared with the F/B-EVAR group. The 30-day mortality was 2.9% and 2.4% (P = .84) in the OR group and F/B-EVAR group, respectively. Supraceliac clamp site was associated with increased incidence of postoperative renal insufficiency. A decrease in procedure time, contrast volume, fluoroscopy time, and fluoroscopy dose was noted in the F/B-EVAR group with increasing experience even as case complexity increased. More patients were discharged home after F/B-EVAR (97.6% vs 59.4%; P < .001). With a mean follow-up of 31 months (F/B-EVAR, 17 months; OR, 48 months), the rate of secondary intervention was 3.7% and 5.8% (P = NS) for F/B-EVAR and OR, respectively. Freedom from branch instability and reintervention was 99% (95% confidence interval, 96.2%-99.8%) and 96% (95% confidence interval, 87.1%-98.6%), respectively.

CONCLUSIONS

Results of this "real-world" experience suggest that the use of F/B-EVAR for the treatment of cAAAs in high-risk surgical patients is safe and effective and has comparable short-term results to those of low-risk patients undergoing OR. Patients treated by F/B-EVAR had shorter ICU and hospital LOS, lower MAEs, and faster convalescence. A decrease in procedure time and radiation dose was noted as experience was gained, even as complexity increased.

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.

Clinical Outcomes of Endovascular Aneurysm Repair with the Kilt Technique for Abdominal Aortic Aneurysms with Hostile Aneurysm Neck Anatomy: A Korean Multicenter Retrospective Study

PURPOSE

We aimed to evaluate the clinical efficacy and short-term clinical outcomes of Kilt technique-based endovascular aneurysm repair (EVAR) with Seal^® stent-grafts for abdominal aortic aneurysms (AAAs) with hostile neck anatomy (angle > 60°).

MATERIALS AND METHODS

We retrospectively evaluated the pre-EVAR and follow-up computed tomography angiography findings of 24 patients (mean age 71 ± 11 years; age range 32-87 years; mean follow-up 50 ± 12 months) with hostile neck AAAs treated between 2010 and 2015. Serial change in aneurysmal neck angle was calculated using a standardized protocol. Relationships between clinical variables and outcomes were evaluated using univariate and multivariate Cox analyses and mixed-model regression. In addition, the Kaplan-Meier method was used to assess the cumulative rates of survival, endoleak, and reintervention.

RESULTS

The primary technical success rate (success within 24 h after EVAR) was 100% (24/24). The survival rate was 96 ± 8% at 1 month, 6 months, 1 year, and 3 years, and 87 ± 18% at 5 years. Endoleaks occurred in three patients. Four reinterventions were performed in three patients; no surgical revisions were required. Causes of post-EVAR mortality included intracerebral hemorrhage at 14 days and rhabdomyolysis at 32 months. The most remarkable change after Kilt-based EVAR was an acute decrease in the neck angle, which was observed between the pre-EVAR and first follow-up visits (at 1 month) (P = 0.001).

CONCLUSION

Kilt-based EVAR with Seal^® stent-grafts for AAAs with a severely angulated neck (angle > 60°) provided high technical success, low mortality, and low complication rates during short-term follow-up.

Validation of an assessment tool for pre-operative EVAR planning

INTRODUCTION

Current methods of teaching endovascular aortic aneurysm repair (EVAR) planning involve non-criteria-based observations that lack validity. The primary aim of this study was to validate an EVAR Planning Objective Structured Assessment of Skill (EpOSAS) tool for the assessment of pre-operative EVAR planning skills.

METHODS

Content analysis was performed in order to inform the formulation of EpOSAS domains. Thirty-five participants planned two cases of infra-renal abdominal aortic aneurysm for EVAR, using the OsiriX 7 platform. EVAR planning measurements, with accompanying screenshots, were uploaded onto an electronic data collection sheet. Performance was assessed by three blinded assessors using the EpOSAS tool. Construct and concurrent validity were evaluated.

RESULTS

Inter-observer reliability for the three assessors for total EpOSAS scores was high (Cronbach's α 0.89). There were statistically significant differences in total EpOSAS scores between the different experience groups, demonstrating construct validity (Novice (5.3, IQR 5-5.3), Intermediate (15.3, IQR 14.8-16.8) and Experts (17.5, IQR 17-17.7), p<0.001). A statistically significant correlation was found between total EpOSAS scores and percentage error in measurements, demonstrating concurrent validity (Spearman's rank correlation coefficient: R=-0.250, p<0.001). Receiver-operator characteristics analysis established a cut-off point of 16 out of 18 for determining competence.

CONCLUSION

We have developed and validated a tool that can be used for the assessment of pre-operative EVAR planning skills.

Editor's Choice - Renal complications after EVAR with suprarenal versus infrarenal fixation among all users and routine users

BACKGROUND

Previous studies comparing endografts with suprarenal and infrarenal fixation for endovascular abdominal aortic aneurysm repair (EVAR) have found conflicting results and did not account for differences in patient selection. This study aims to evaluate the differences in outcomes among surgeons who routinely use either suprarenal or infrarenal fixation, as well as all surgeons in the Vascular Study Group of New England (VSGNE).

METHODS

All patients undergoing EVAR in the VSGNE from 2003 to 2014 were identified. All ruptured aneurysms, repairs with concomitant procedures, and infrequently used stent grafts (<50) were excluded. Suprarenal endografts included Talent, Zenith, and Endurant; infrarenal endografts included AneuRx and Excluder. Grafts were compared among surgeons who used only one type of endograft (suprarenal or infrarenal) for >80% of cases, as well as all surgeons. Multivariate regression and Cox hazard models were utilised to account for patient demographics, comorbidities, operative differences, and procedure year.

RESULTS

This study identified 2574 patients (suprarenal, 1264; infrarenal, 1310) with 888 endografts placed by routine users (suprarenal, 409; infrarenal, 479). There were no differences in baseline comorbidities, including the estimated glomerular filtration rate, between suprarenal and infrarenal fixation, or between patients with endografts placed by routine and non-routine users. Patients treated with suprarenal endografts received more contrast than all users (102 mL vs. 100 mL, p = .01) and routine users (110 mL vs. 88 mL, p < .01), but other vascular and operative details were similar. Among all users, patients treated with suprarenal grafts had higher rates of creatinine increase >.5 mg/dL (3.7% vs. 2.0%, p = .01), length of stay >2 days (27% vs. 19%, p < .01), and discharge to a skilled nursing facility (9.2% vs. 6.7%, p = .02). There were no differences in 30 day or 1 year mortality. Following adjustment, suprarenal stent grafts remained associated with an increased risk of renal deterioration (OR 2.0; 95% CI 1.2-3.4) and prolonged length of stay (OR 1.8; 95% CI 1.4-2.2). Among routine users, suprarenal fixation was also associated with higher rates of renal dysfunction (3.7% vs. 1.3%, p = .02; OR 2.9; 95% CI 1.1-7.8).

CONCLUSION

Despite potential differences in patient selection, endografts with suprarenal fixation among all users and routine users were associated with higher rates of renal deterioration and longer length of hospital stay. Longer-term data are needed to determine the duration and severity of renal function decline and to identify potential benefits of decreased migration or endoleak.

Morphological and Biomechanical Features in Abdominal Aortic Aneurysm with Long and Short Neck-Case-Control Study in 64 Abdominal Aortic Aneurysms

BACKGROUND

Both, open and endovascular, procedures are related to higher complication rate in abdominal aortic aneurysm (AAA) with shorter neck. Previous study showed that long-neck AAA might have lower risk of rupture. Estimation of biomechanical forces in AAA improves rupture risk assessment. The aim of this study was to compare morphological features and biomechanical forces in the short- and long-neck AAA with threshold of 15 mm.

METHODS

Digital Imaging and Communication in Medicine images of 64 aneurysms were prospectively collected and analyzed in a case-control study. Using commercially available software, Peak wall Stress (PWS) and Rupture Risk Equivalent Diameter (RRED) were determined. Difference between the maximal aneurysm diameter (MAD) and RRED was calculated and expressed as an absolute and relative (percentage of the MAD) value. In addition, volume of intraluminal thrombus (ILT) was calculated and expressed relative to AAA volume.

RESULTS

Study included 64 AAA divided in group with long (36, 56.25%), and short (28, 43.75%) neck. There was no correlation between neck length and MAD, PWS, and RRED (P = 0.646, P = 0.421, and P = 0.405, respectively). Relative ILT volume was greater in the short-neck aneurysms (P = 0.033). Relative difference between RRED and MAD was -4% and -14.8% in short- and long-neck aneurysms, respectively (P = 0.029). The difference between RRED and MAD was positive in 14/28 patients (50%) with short neck and in 6/35 patients (17.14%) with long neck (P = 0.011).

CONCLUSIONS

Based on our biomechanical analysis, in AAA with neck longer than 15 mm rupture risk might be lower than the risk estimated by its diameter. It might be explained with lower relative volume of ILT.