Meta-analysis of individual-patient data from EVAR-1, DREAM, OVER and ACE trials comparing outcomes of endovascular or open repair for abdominal aortic aneurysm over 5 years

Management of Abdominal Aortic Aneurysm Disease: Similarities and Differences Among Cardiovascular Guidelines and NICE Guidance

The development of endovascular techniques has improved abdominal aortic aneurysm (AAA) management over the past 2 decades. Different cardiovascular societies worldwide have recommended the endovascular approach as the standard of care in their currently available guidelines. While endovascular treatment has established its role in daily clinical practice, a new debate has arisen regarding the indications, appropriateness, limitations, and role of open surgery. To inform this debate, the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched from 2010 to May 2020; the systematic search identified 5 articles published between 2011 and 2020 by 4 cardiovascular societies and the National Institute of Health and Care Excellence (NICE). Four debatable domains were assessed and analyzed: diagnostic methods and screening, preoperative management, indications and treatment modalities, and postoperative follow-up and endoleak management. The review addresses controversial proposals as well as widely accepted recommendations and "gray zone" issues that need to be further investigated and analyzed, such as screening in women, medical management, and follow-up imaging. While the recommendations for AAA management have significant overlap and agreement among international cardiovascular societies, the NICE guidelines diverge regarding the role of open repair in aortic disease, recommending conventional surgery in most elective cases.

Type II Endoleaks After EVAR: A Literature Review of Current Concepts

Endoleak is the most frequent complication following endovascular aneurysm repair, which is not present in the surgical counterpart. The most frequent type of endoleak corresponds to type II, and its natural history remains poorly understood. Therefore, their treatment continues to be a topic of debate. The vast majority of the studies found in the literature are of a retrospective nature, and there are no prospective studies comparing intervention versus a conservative approach. Future studies should aim to compare not only different approaches to resolve type II endoleak but also when should be the right time to treat them, with the primary purpose of avoiding sac rupture. The objective of this review is to provide the reader with a literature overview about type II endoleaks to help in the decision-making process on this topic.

Predictors of Abdominal Aortic Aneurysm Risks

Computational biomechanics via finite element analysis (FEA) has long promised a means of assessing patient-specific abdominal aortic aneurysm (AAA) rupture risk with greater efficacy than current clinically used size-based criteria. The pursuit stems from the notion that AAA rupture occurs when wall stress exceeds wall strength. Quantification of peak (maximum) wall stress (PWS) has been at the cornerstone of this research, with numerous studies having demonstrated that PWS better differentiates ruptured AAAs from non-ruptured AAAs. In contrast to wall stress models, which have become progressively more sophisticated, there has been relatively little progress in estimating patient-specific wall strength. This is because wall strength cannot be inferred non-invasively, and measurements from excised patient tissues show a large spectrum of wall strength values. In this review, we highlight studies that investigated the relationship between biomechanics and AAA rupture risk. We conclude that combining wall stress and wall strength approximations should provide better estimations of AAA rupture risk. However, before personalized biomechanical AAA risk assessment can become a reality, better methods for estimating patient-specific wall properties or surrogate markers of aortic wall degradation are needed. Artificial intelligence methods can be key in stratifying patients, leading to personalized AAA risk assessment.

Human Umbilical Cord Mesenchymal Stem Cells Attenuate Abdominal Aortic Aneurysm Progression in Sprague-Dawley Rats: Implication of Vascular Smooth Muscle Cell Phenotypic Modulation

Abdominal aortic aneurysm (AAA) is life-threatening, for which efficient nonsurgical treatment strategy has not been available so far. Several previous studies investigating the therapeutic effect of mesenchymal stem cells (MSCs) in AAA indicated that MSCs could inhibit aneurysmal inflammatory responses and extracellular matrix destruction, and suppress aneurysm occurrence and expansion. Vascular smooth muscle cell (VSMC) phenotypic plasticity is reported to be predisposed in AAA initiation and progression. However, little is known about the effect of MSCs on VSMC phenotypic modulation in AAA. In this study, we investigate the therapeutic efficacy of umbilical cord mesenchymal stem cells (UC-MSCs) in elastase-induced AAA model and evaluate the effect of UC-MSC on VSMC phenotypic regulation. We demonstrate that the intravenous injection of UC-MSC attenuates elastase-induced aneurysmal expansion, reduces elastin degradation and fragmentation, inhibits MMPs and TNF-α expression, and preserves and/or restores VSMC contractile phenotype in AAA. Taken together, these results highlight the therapeutic and VSMC phenotypic modulation effects of UC-MSC in AAA progression, which further indicates the potential of applying UC-MSC as an alternative treatment candidate for AAA.

Surgery for small asymptomatic abdominal aortic aneurysms

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal ballooning of the major abdominal artery. Some AAAs present as emergencies and require surgery; others remain asymptomatic. Treatment of asymptomatic AAAs depends on many factors, but the size of the aneurysm is important, as risk of rupture increases with aneurysm size. Large asymptomatic AAAs (greater than 5.5 cm in diameter) are usually repaired surgically; very small AAAs (less than 4.0 cm diameter) are monitored with ultrasonography. Debate continues over the roles of early repair versus surveillance with repair on subsequent enlargement in people with asymptomatic AAAs of 4.0 cm to 5.5 cm diameter. This is the fourth update of the review first published in 1999.

OBJECTIVES

To compare mortality and costs, as well as quality of life and aneurysm rupture as secondary outcomes, following early surgical repair versus routine ultrasound surveillance in people with asymptomatic AAAs between 4.0 cm and 5.5 cm in diameter.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, two other databases, and two trials registers to 10 July 2019. We handsearched conference proceedings and checked reference lists of relevant studies.

SELECTION CRITERIA

We included randomised controlled trials where people with asymptomatic AAAs of 4.0 cm to 5.5 cm were randomly allocated to early repair or imaging-based surveillance at least every six months. Outcomes had to include mortality or survival.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, which were cross-checked by other team members. Outcomes were mortality, costs, quality of life, and aneurysm rupture. For mortality, we estimated risk ratios (RR) (endovascular aneurysm repair only), hazard ratios (HR) (open repair only), and 95% confidence intervals (CI) based on Mantel-Haenszel Chi² statistics at one and six years (open repair only) following randomisation.

MAIN RESULTS

We found no new studies for this update. Four trials with 3314 participants fulfilled the inclusion criteria. Two trials compared early open repair with surveillance and two trials compared early endovascular repair (EVAR) with surveillance. We used GRADE to access the certainty of the evidence for mortality and cost, which ranged from high to low. We downgraded the certainty in the evidence from high to moderate and low due to risk of bias concerns and imprecision (some outcomes were only reported by one study). All four trials showed an early survival benefit in the surveillance group (due to 30-day operative mortality with repair) but no evidence of differences in long-term survival. One study compared early open repair with surveillance with an adjusted HR of 0.88 (95% CI 0.75 to 1.02, mean follow-up 10 years; HR 1.21, 95% CI 0.95 to 1.54, mean follow-up 4.9 years). Pooled analysis of participant-level data from the two trials comparing early open repair with surveillance (maximum follow-up seven to eight years) showed no evidence of a difference in survival (propensity score-adjusted HR 0.99, 95% CI 0.83 to 1.18; 2226 participants; high-certainty evidence). This lack of treatment effect did not vary to three years by AAA diameter (P = 0.39), participant age (P = 0.61), or for women (HR 0.84, 95% CI 0.62 to 1.11). Two studies compared EVAR with surveillance and there was no evidence of a survival benefit for early EVAR at 12 months (RR 1.92, 95% CI 0.73 to 5.06; 846 participants; low-certainty evidence). Two trials reported costs. The mean UK health service costs per participant over the first 18 months after randomisation were higher in the open repair surgery than the surveillance group (GBP 4978 in the repair group versus GBP 3914 in the surveillance group; mean difference (MD) GBP 1064, 95% CI 796 to 1332; 1090 participants; moderate-certainty evidence). There was a similar difference after 12 years. The mean USA hospital costs for participants at six months after randomisation were higher in the EVAR group than in the surveillance group (USD 33,471 with repair versus USD 5520 with surveillance; MD USD 27,951, 95% CI 25,156 to 30,746; 614 participants; low-certainty evidence). After four years, there was no evidence of a difference in total medical costs between groups (USD 48,669 with repair versus USD 46,112 with surveillance; MD USD 2557, 95% CI -8043 to 13,156; 614 participants; low-certainty evidence). All studies reported quality of life but used different assessment measurements and results were conflicting. All four studies reported aneurysm rupture. There were very few ruptures reported in the trials of EVAR versus surveillance up to three years. In the trials of open surgery versus surveillance, there were ruptures to at least six years and there were more ruptures in the surveillance group, but most of these ruptures occurred in aneurysms that had exceeded the threshold for surgical repair.

AUTHORS' CONCLUSIONS

There was no evidence of an advantage to early repair for small AAA (4.0 cm to 5.5 cm), regardless of whether open repair or EVAR is used and, at least for open repair, regardless of patient age and AAA diameter. Thus, neither early open nor early EVAR of small AAAs is supported by currently available evidence. Long-term data from the two trials investigating EVAR are not available, so, we can only draw firm conclusions regarding outcomes after the first few years for open repair. Research regarding the risks related to and management of small AAAs in ethnic minorities and women is urgently needed, as data regarding these populations are lacking.

Impact of Gradual Adoption of EVAR in Elective Repair of Abdominal Aortic Aneurysm: A Retrospective Cohort Study from 2009 to 2015

INTRODUCTION

The recommendations about the preferred type of elective repair of abdominal aortic aneurysm (AAA) still divides guidelines committees, even nowadays. The aim is to assess outcomes after AAA repair focusing on differences between endovascular aneurysm repair (EVAR) and open surgical repair (OSR).

METHODS

The observational retrospective cohort study of consecutive patients submitted to elective AAA repair at a tertiary center, 2009-2015. Exclusion criteria were as follows: nonelective cases or complex aortic aneurysms. Primary outcomes were postoperative complications, length of hospital stay, survival, freedom from aortic-related mortality, and vascular reintervention. Time trends were assessed along the period under analysis.

RESULTS

From a total of 211 included patients, those submitted to EVAR were older (74 ± 7 vs. 67 ± 9 years; P < 0.001), presented a higher prevalence of hypertension (83.5% vs. 68.5%, P = 0.004), obesity (28.7% vs. 14.3%, P = 0.029), previous cardiac revascularization (30.5% vs. 14.7%, P = 0.005), heart failure (17.2% vs. 5.2%, P = 0.013), and chronic obstructive pulmonary disease (32.8% vs. 13.3%, P = 0.002). Patients were followed during a median of 49 months. EVAR resulted in a significantly shorter length of hospital stay (median 4 and interquartile range 3 vs. 8 (9); P < 0.001), lower 30-day complications (10.6% vs. 22.8%, P = 0.017), lower aortic-related mortality, and similar reintervention after adjustment with a propensity score. Along the time under analysis, EVAR became the predominate type of repair (P = 0.024), the proportion of complications decreased (P = 0.014), and the 30-day mortality (P = 0.035).

CONCLUSIONS

Although EVAR was offered to patients with more comorbidities, better and durable outcomes were achieved after EVAR, favoring its adoption for elective AAA repair.

Type IA endoleak caused by interlocked suprarenal bare-metal stents after endovascular abdominal aortic aneurysm repair with successful endovascular rescue

A physically active 90-year-old man underwent endovascular repair of an asymptomatic but enlarging abdominal aortic aneurysm. Postoperative computed tomography demonstrated entanglement of nonadjacent proximal bare-metal stents. This was associated with graft infolding and a type IA endoleak. The patient underwent percutaneous transluminal angioplasty and placement of a Palmaz stent. Subsequent surveillance imaging showed resolution of the type I endoleak >1 year later. This report demonstrates an uncommon cause of stent graft infolding, an already rare complication of endovascular aneurysm repair, and highlights the need to carefully assess the morphologic appearance of the proximal fixation stents after graft deployment.

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

Background

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

Methods

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

Results

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

Conclusions

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

Registration

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

Elective late open conversion after endovascular aneurysm repair is associated with comparable outcomes to primary open repair of abdominal aortic aneurysms

OBJECTIVE

Three of four patients with infrarenal abdominal aortic aneurysm are now treated with endovascular aneurysm repair (EVAR). The incidence of secondary procedures and surgical conversions is increasing for a population theoretically unfit for open surgery. The indications and outcomes of late open surgical conversions after EVAR in a high-volume tertiary vascular unit are reported.

METHODS

This retrospective single-center study includes all patients who underwent a late open conversion between January 1996 and July 2018. Data were collected from records on patient demographics, operative indications, surgical strategy, perioperative outcomes, and medium-term survival.

RESULTS

Sixty-two consecutive patients (88.7% male) with a mean age of 77.5 years are included. The median duration since index EVAR was 38.5 months; 65% of stent grafts requiring late open conversion had suprarenal fixation. Indications included 22.6% type IA, 16.1% type IB, and 45.2% type II endoleaks; 12.9% graft thrombosis; and 14.5% endoprosthesis infection. Complete endograft explantation was performed in 37.1% of patients and a partial explantation in 54.8%, whereas 8.1% of stent grafts were wholly preserved in situ. Overall 30-day mortality was 12.9% (n = 8) in the cohort and 2.7% for elective patients. The all-cause morbidity rate was 40.1%, and the median length of hospital stay was 9 days. After follow-up of 28.4 months (range, 1.8-187.3 months), all-cause survival was 58.8%. Avoidance of aortic clamping (P = .006) and elective procedures (P = .019) were associated with a significant reduction in the length of hospital stay. Moreover, the 30-day mortality (P = .002), occurrence of postoperative renal dysfunction (P = .004), and intestinal ischemia (P = .017) were increased in the emergency setting. Excluding cases with rupture or infection, survival estimates were 97%, 97%, and 71% at 1 year, 2 years, and 5 years, respectively.

CONCLUSIONS

Technically more complex than primary open surgery, late open conversion is a procedure that generates an acceptable perioperative risk when it is performed in a high-volume aortic surgical center. Elective open conversion is associated with excellent early and late outcomes. Endograft preservation strategies decrease perioperative morbidity.

Quantification of suprarenal aortic neck dilation after fenestrated endovascular aneurysm repair

OBJECTIVE

Suprarenal aortic neck dilation (AND) after fenestrated endovascular aneurysm repair (FEVAR) with commercially available devices has not yet been well characterized. The aim of this study was to measure diameter changes in the supravisceral aorta after FEVAR.

METHODS

This is a single-center retrospective review involving patients with juxtarenal aneurysms treated with Cook ZFEN devices (Cook Medical, Bloomington, Ind). Patients with at least 1 year of cross-sectional radiologic follow-up were included. AND was defined as ≥3 mm at any measured location. Aortic diameter, defined as the average outer to outer diameter on three-dimensional centerline imaging, was measured at seven locations along the length of the ZFEN device from the proximal fixation struts to the bottom of the second seal stent. The first postoperative CT scan (≤1 month) served as a baseline from which subsequent measurements at annual intervals were compared.

RESULTS

A total of 43 patients who underwent FEVAR from 2012 to 2018 met inclusion criteria, with a total of 119 target vessels (83 renal stents, 41 superior mesenteric artery scallops or large fenestrations). Mean follow-up time was 30.3 months. Any AND was found to occur in 32 (74.4%) patients. Aortic diameter dilation at latest follow-up was found to occur at all measured locations from the top of the fixation struts (1.9 ± 2.4 mm; P < .0001) to the middle of the second seal stent (1.3 ± 3.8 mm; P < .01). Diameter growth was most pronounced in the middle of the first seal stent, with mean AND of 3.6 ± 3.2 mm. At this location, the aorta experienced nearly linear annual growth of 0.99 mm (95% confidence interval, 0.7-1.28 mm) per year. Increasing device oversizing relative to the native visceral aorta was the strongest predictor of postoperative neck diameter growth (1.34 mm per 10% increase in oversizing; P = .02), whereas increasing proximal seal length was protective of growth (-1.82 mm per 10-mm increase in seal length; P = .016). Proximal seal lengths ≥3 cm were associated with less neck dilation compared with <3 cm (2.6 mm vs 4.9 mm; P = .022). Type IA endoleak in this cohort was rare (n = 1) and not associated with AND (P = .256).

CONCLUSIONS

Dilation of the suprarenal aorta is a common finding in midterm follow-up after FEVAR and not associated with proximal endoleak. Aggressive device oversizing is predictive of dilation, whereas longer seal lengths are associated with less dilation along the suprarenal seal zone. These results support the continued use of FEVAR for juxtarenal aneurysms, particularly in patients in whom ≥3 cm of healthy seal length can be obtained.

Outcomes of endosutured aneurysm repair with the Heli-FX EndoAnchor implants

OBJECTIVE

Endovascular aneurysm repair has gained field over open surgery for the treatment of abdominal aortic aneurysm. However, type Ia endoleak represents a common complication especially in hostile neck anatomy that is recently faced using endoanchors. We conducted a systematic review and meta-analysis to collect and analyse all the available comparative evidence on the outcomes of the endosuture aneurysm repair in patients with or without hostile neck in standard endovascular aneurysm repair.

METHODS

The current meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All the prospective and retrospective studies reporting primary use of the Heli-FX EndoAnchor implants were considered eligible for inclusion in this study. The main study outcomes (technical success of endoanchor implantation, incidence of type Ia endoleak, aortic stent graft migration and the percentage of patients who presented regression or expansion of aneurysm sac throughout the follow-up) were subsequently expressed as proportions and 95% confidence intervals.

RESULTS

Eight studies with a total of 968 patients were included in a pooled analysis. The technical success of the primary endoanchor fixation was 97.12% (95%CI: 92.98-99.67). During a mean six months follow-up period, a pooled rate of 6.23% (95%CI: 0.83-15.25) of the patients developed a persistent type Ia endoleak despite the primary implantation. Migration of the main graft was reported in five studies, in which a 0.26% (95%CI = 0.00-1.54) of the patients required an additional proximal aortic cuff. Regression of the aneurysm sac was observed at 68.82% (95%CI: 51.02-84.21). An expansion of the aneurysm sac was found in 1.93% (95%CI: 0.91-3.24) of the participants. The overall survival rate was 93.43% (95%CI: 89.97-96.29) at a mean six months follow-up period.

CONCLUSIONS

Endosuture aneurysm repair with the Heli-FX EndoAnchor implants seems to be technically feasible and safe either for prevention or for repair of intraoperative type Ia endoleak. Despite the primary implants of endoanchors, few cases of persistent type Ia endoleak and migration are still conspicuous. Long-term follow up is needed to determinate the role of this therapeutic option in the treatment of aortic aneurysms.

Renal Dysfunction Following Elective Endovascular Aortic Aneurysm Repair

Abdominal aortic aneurysm (AAA) is a degenerative disease of the aortic wall with potentially fatal complications. Open repair (OR) was considered the gold standard, until the emergence of endovascular aneurysm repair (EVAR), which is less invasive and equally (if not more) effective. As the popularity of endovascular procedures grows, related complications become more evident, with kidney damage being one of them. Although acute kidney injury (AKI) following EVAR is relatively common, its true incidence is still uncertain. Also, there is insufficient data concerning long-term renal outcomes after EVAR, especially with repeated contrast agent exposure. Despite the lack of firm evidence on the effectiveness of individual strategies, it is evident that prevention of AKI following EVAR requires a multifactorial approach. This review focuses on recent findings based on human studies regarding the current evidence of renal impairment after EVAR, its quantification and strategies for its prevention.

Meta-analysis of phase-specific survival after elective endovascular versus surgical repair of abdominal aortic aneurysm from randomized controlled trials and propensity score-matched studies

OBJECTIVE

Although endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) significantly decreases perioperative mortality compared with open surgical repair (OSR), we have not concluded superiority between EVAR and OSR beyond the perioperative period. The aim of this study was to compare phase-specific survival after EVAR vs OSR.

METHODS

The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Embase and MEDLINE were searched up to November 2019 to identify randomized controlled trials and propensity score-matched studies that investigated ≥2-year all-cause mortality (primary outcome) after EVAR vs OSR for intact infrarenal AAA. For each study, the hazard ratio (HR) with 95% confidence interval (CI) of mortality for EVAR vs OSR was calculated using survival curves for the following specific phases: early term (0-2 years after repair), midterm (2-6 years after repair), long term (6-10 years after repair), and very long term (≥10 years after repair). The risk ratio (RR) in the perioperative (in-hospital or 30-day) period was also extracted. Phase-specific HRs or RRs were separately pooled using the random effects model. Sensitivity analyses were performed by removing one study at a time to confirm that our findings were not derived from any single study. Funnel plot asymmetry was also examined using the linear regression test.

RESULTS

Our search identified four randomized controlled trials and seven propensity score-matched studies enrolling a total of 106,243 AAA patients assigned to EVAR (n = 53,123) or OSR (n = 53,120). The mortality after EVAR compared with OSR was significantly lower in the perioperative period (RR, 0.39; 95% CI, 0.29-0.51; P < .00001) and similar in the early-term period (HR, 0.93; 95% CI, 0.84-1.03; P = .16). Notably, significantly higher mortality was observed in the EVAR group compared with the OSR group in the midterm period (HR, 1.15; 95% CI, 1.03-1.29; P = .01). However, similar mortality was observed between the EVAR group and the OSR group in the long-term (HR, 1.06; 95% CI, 0.96-1.17; P = .27) and very-long-term (HR, 1.17; 95% CI, 0.93-1.47; P = .19) periods. In sensitivity analyses, the significant benefit of EVAR in the perioperative period and that of OSR in the midterm period were not changed. No funnel plot asymmetry was identified in all analyses.

CONCLUSIONS

Compared with OSR, EVAR was associated with lower perioperative mortality and higher mortality in the midterm period for intact infrarenal AAA. The superiority of EVAR was absent in the early-term period, and the inferiority of EVAR in the midterm period disappeared in the long-term and very-long-term periods.

The role of cardiopulmonary exercise testing and echocardiography prior to elective endovascular aneurysm repair

INTRODUCTION

Cardiopulmonary exercise testing (CPET) and transthoracic echocardiography (TTE) are common preparative investigations prior to elective endovascular aneurysm repair (EVAR). Whether these investigations can predict survival following EVAR and contribute to shared decision making is unknown.

METHODS

Patients who underwent EVAR at a tertiary centre between June 2007 and December 2014 were identified from the National Vascular Registry. Variables obtained from preoperative investigations were assessed for their association with survival at three years. Regression analysis was used to determine variables that independently predicted survival at three years.

RESULTS

A total of 199 patients underwent EVAR during the study period. Of these, 120 had preoperative CPET and 123 had TTE. Lower forced expiratory ventilation (FEV₁), ratio of FEV₁ to forced vital capacity, work at peak oxygen consumption and higher ventilatory equivalent for carbon dioxide were associated with increased mortality. Variables obtained from TTE were not associated with survival at three years although there was a low incidence of left ventricular systolic dysfunction and significant valvular disease in this cohort.

CONCLUSIONS

CPET might be a useful adjunct to assist in shared decision making in patients undergoing elective EVAR and may influence anaesthetic technique. TTE does not appear to be able to discriminate between high and low risk individuals. However, a low rate of significant ventricular dysfunction and valvular disease in patients undergoing elective EVAR may account for these findings.

Adjunctive Procedures for Challenging Endovascular Abdominal Aortic Repair: When Needed and How Effective?

Endovascular aneurysm repair (EVAR) is now considered the first choice treatment modality for abdominal aortic aneurysm (AAA) treatment. Advocates for endovascular strategies will try to treat all AAA by EVAR, regardless if the anatomy is conducive for treatment or not. However, the long-term outcomes of EVAR outside the instructions for use (IFU) due to a hostile aneurysmal neck or iliac artery anatomy are known to be poor. The EVAR procedures can be classified according to the technical difficulty, IFU, and need for visceral revascularization: standard, adjunctive, and complex EVAR. The situation required for adjunctive procedures can be classified as the following four steps: a hostile neck (i.e., short or severely angled); large inferior mesenteric or lumbar artery; tough iliac artery anatomy, such as a short common iliac artery and stenotic external iliac artery; and limitations in vascular access. This article will discuss the adjunctive procedures to overcome hostile aneurysm neck and unsuitable iliac artery anatomy.

Infrarenal Abdominal Aortic Aneurysm Endovascular Treatment: Long-term Results From a Single-Center Experience in an Unselected Patient Population

BACKGROUND

The aim of the present study was to evaluate early-, mid-, and long-term outcomes in an unselected population of patients treated for abdominal aortic aneurysms (AAAs) by endovascular aneurysm repair (EVAR) with different commercially available off-the-shelf devices.

MATERIALS AND METHODS

A retrospective study was conducted on a prospectively compiled computerized database on patients presenting an infrarenal AAA treated between January 2008 and December 2015 in a high-volume Italian tertiary referral Center. Demographic, clinical, and specific morphological features were considered as potentially influencing the outcomes and the type of the implanted device. Outcome measures were procedure-related reintervention, AAA-related, and all-cause mortality rates at 30-day, 12-month, and long-term follow-up. Reinterventions considered for the analysis were AAA rupture, graft infection, type I or III endoleaks, type II endoleaks with sac enlargement > 5 mm, graft stenosis or occlusions, procedures related to renal or visceral ischemia, and reintervention for access vessel injury.

RESULTS

Of 498 EVAR procedures performed for elective infrarenal AAA treatment during the entire study period, 479 patients were enrolled, the mean age was 73.5 ± 7.34 years (range 51-91), and 416 (86.84%) were men. The mean maximum AAA diameter was 52.02 ± 8.04 mm (range 39-90.2), a maximum AAA diameter ≥59 mm was recorded in 107 patients (22.33%), and an aortic neck length was <10 mm in 137 (28.60%). Technical success was achieved in all patients. At a mean follow-up of 52.97 ± 26.16 months (range 1-120), overall reintervention and death rates were 8.14% and 20.04%, respectively, without AAA-related deaths. At univariate analysis, hypertension was the only demographical variable found to be associated with higher risk of reintervention, P = 0.04 (OR: 2.34; CI 95%: 1.00-5.42). Furthermore, male sex (P = 0.02; OR: 2.62; CI 95%: 1.09-6.27) and chronic renal insufficiency (P = 0.003; OR: 2.08; CI 95%: 1.27-3.42) were associated with higher mortality rates. AAA diameter ≥59 mm was statistically associated with a higher rate of both reintervention and mortality: P < 0.001 (OR: 9.05; CI 95%: 4.52-18.11) and <0.001 (4.00; 2.46-6.49), respectively.

CONCLUSIONS

Our experience seems to suggest that EVAR could be safely and effectively performed in an unselected patients' population, with encouraging results up to a ten-year follow-up.

Clinical evaluation of endovascular repair of abdominal aortic aneurysm based on long-term experiences

Introduction

The endovascular method as a less invasive treatment for patients with abdominal aortic aneurysm (AAA) has become an alternative to conventional open surgery.

Aim

The objective of the present study was to analyse the outcomes of endovascular treatment of AAA patients in long-term observation.

Material and methods

A group of 236 AAA patients subjected to planned endovascular aneurysm repair (EVAR) between 2010 and 2015 was reviewed. Rates of mortality, surgical complications and re-interventions were collected in the separate time periods, i.e. up to 30 days after surgery, 30 days to 3 years, and from 3 to 5 years after surgery. Cumulative rates of these parameters were evaluated in the short-term (up to 30 days after surgery), medium-term (up to 3 years), and long-term (up to 5 years after surgery) perspective.

Results

The median age of patients was 75 years, and the most common comorbidities were arterial hypertension (54%) and ischaemic heart disease (52%). Cumulative short-, medium- and long-term mortality rates were 2.5%, 14.2% and 28.9%, respectively. Total rates of surgical complications in short-, medium- and long-term observation were 7.6%, 12.6% and 17.5%, respectively. The cumulative rate of re-interventions ranged from 4.2% to 11.4%.

Conclusions

In the consecutive time periods, the increase in the percentage of surgical complications and re-interventions increased gradually, in contrast to mortality, where the curve grew significantly, which is expected due to the aging and numerous comorbidities in the observed group of patients.

Long-Term Outcomes of Endovascular vs Open Surgical Repair for Abdominal Aortic Aneurysms: A Meta-Analysis of Randomized Trials

OBJECTIVE

The aim of this meta-analysis was to investigate whether Endovascular abdominal aortic aneurysm repair (EVAR) is inferior to open surgical repair in terms of adverse events during late follow up, defined as >8 years after the procedure.

BACKGROUND

EVAR is associated with reduced morbidity and mortality compared to open surgery in the early perioperative period. However, it is unknown whether this pattern remains during long-term follow up >8 years.

METHODS

A meta-analysis was conducted with the use of random effects modeling. Hazard ratios were calculated for mortality at different time intervals, and risk ratios were calculated in cases where the total number of events was available.

RESULTS

There was no difference in all-cause mortality during follow up of each study (HR: 1.04; 95%CI: 0.93-1.17; I² = 16.0%). Subgroup analyses for all-cause mortality at 4 to 8 years of follow up (HR: 1.13; 95%CI: 0.94-1.35; I² = 0.0%) and all-cause mortality at follow up >8 years (HR: 1.07; 95%CI: 0.89-0.28; I² = 36.6%) also did not show any significant difference between the two approaches. The risks of aneurysm-related mortality and aneurysm rupture were similar during follow-up. However, the cumulative risk for reintervention during follow up was greater in the EVAR group (RR: 2.18; 95%CI: 1.50-3.17; I² = 76.1%) and occurred in 29% vs 15% of patients in the EVAR vs surgery groups respectively.

CONCLUSIONS

EVAR and open surgical repair of AAA are equally safe and have no difference in all-cause mortality. However, endovascular repair is associated with an increased need for re-intervention. Emerging technology in endovascular devices will likely further improve the outcomes of EVAR. Subject codes: Meta-analysis; aneurysm; atherosclerosis; complications.

Sex differences in perioperative outcomes after complex abdominal aortic aneurysm repair

OBJECTIVE

Female sex is associated with worse outcomes after infrarenal abdominal aortic aneurysm (AAA) repair. However, the impact of female sex on complex AAA repair is poorly characterized. Therefore, we compared outcomes between female and male patients after open and endovascular treatment of complex AAA.

METHODS

We identified all patients who underwent complex aneurysm repair between 2011 and 2017 in the American College of Surgeons National Surgical Quality Improvement Program targeted vascular module. Complex repairs were defined as those for juxtarenal, pararenal, or suprarenal aneurysms. We compared rates of perioperative adverse events between female and male patients stratified by open AAA repair and endovascular aneurysm repair (EVAR). We calculated propensity scores and used inverse probability-weighted logistic regression to identify independent associations between female sex and our outcomes.

RESULTS

We identified 2270 complex aneurysm repairs, of which 1260 were EVARs (21.4% female) and 1010 were open repairs (30.7% female). After EVAR, female patients had higher rates of perioperative mortality (6.3% vs 2.4%; P = .001) and major complications (15.9% vs 7.6%; P < .001) compared with male patients. In contrast, after open repair, perioperative mortality was not significantly different (7.4% vs 5.6%; P = .3), and the rate of major complications was similar (29.4% vs 27.4%; P = .53) between female and male patients. Furthermore, even though perioperative mortality was significantly lower after EVAR compared with open repair for male patients (2.4% vs 5.6%; P = .001), this difference was not significant for women (6.3% vs 7.4%; P = .60). On multivariable analysis, female sex remained independently associated with higher perioperative mortality (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.3-4.9; P = .007) and major complications (OR, 2.0; 95% CI, 1.3-3.2; P = .002) in patients treated with EVAR but showed no significant association with mortality (OR, 0.9; 95% CI, 0.5-1.6; P = .69) or major complications (OR, 1.1; 95% CI, 0.8-1.5; P = .74) after open repair. However, the association of female sex with higher perioperative mortality in patients undergoing complex EVAR was attenuated when diameter was replaced with aortic size index in the multivariable analysis (OR, 1.9; 95% CI, 0.9-3.9; P = .091).

CONCLUSIONS

Female sex is associated with higher perioperative mortality and more major complications than for male patients after complex EVAR but not after complex open repair. Continuous efforts are warranted to improve the sex discrepancies in patients undergoing endovascular repair of complex AAA.

The effect of Endovascular Aneurysm Repair on Renal Function in Patients Treated for Abdominal Aortic Aneurysm

Aim:

The effect of endovascular aneurysm repair in patients treated for abdominal aortic aneurysm has not been clearly defined. The objective of the present article was to provide a contemporary literature review and perform an analysis to determine the effect of EVAR on renal function in the early post-operative period and during follow-up.

Methods:

A systematic review of the literature was undertaken to identify all studies reporting the effect of EVAR on renal function. Outcome data were pooled and combined overall effect sizes were calculated using fixed or random-effects models.

Results:

Thirty-two studies reporting on 24846 patients were included. Acute renal failure after EVAR occurred with an estimated frequency of 9% (95%CI: 5-16%; I2=97%). Median follow-up period was 19.5 months (range 1-60 months). The estimated frequency of chronic renal failure during follow-up was 7% (95%CI: 3-17%; I2=98%). Hemodialysis was required in 2% (1-3%; I2=97%) of the cases.

Conclusion:

High-level evidence demonstrating the effect of EVAR on the incidence of acute and chronic renal failure is lacking. Based on the current available data, nearly 10% of patients undergoing EVAR for AAA have an increased risk for renal dysfunction after the procedure. Whether this deterioration may lead to a worse outcome has not been adequately proved.

[Hybrid operating theater]

A hybrid suite is an operating theater with imaging equipment equivalent to that used in an angiography suite with computed tomography (CT) and magnetic resonance imaging (MRI). They are often situated outside the operating room area and typically serve as multifunctional rooms designed to support a variety of catheter-based endovascular procedures and open surgery to be performed in the same location. The possibility to perform these in the same location facilitates the combination of both approaches to so-called hybrid procedures. Typical clinical applications of hybrid suites are cardiac, thoracic and vascular surgery, neurosurgery and neuroradiology, as well as orthopedics and traumatology. Transcatheter aortic valve implantation (TAVI) is significantly less invasive than a classical approach by open surgery. Patients older than 75 years with relevant comorbidities benefit most from the minimally invasive interventional approach. There has been a paradigm shift in the management of vascular diseases from open surgical repair to new percutaneous endovascular interventions with good early outcomes. Of particular interest in this context is the ability to block the part of the aorta proximal to the aneurysm with a catheter-based dilatation balloon. Progress in image fusion technology and intraoperative navigation has led to an increased acceptance of hybrid suites in orthopedics and traumatology. The complex care of high-risk patients most often outside the operating theater area is a challenge for the anesthesia team. This demands meticulous planning on behalf of the anesthesiologist to ensure an appropriate and safe strategy for anesthesia, intraoperative monitoring, vascular access and the need for additional equipment. A thorough understanding of the complexity of procedures is vital and a series of questions must be addressed: what is needed to safely administer anesthesia in this environment? What additional resources would be needed for an emergency situation? Is the patient being kept safe from radiation hazards? Moreover, logistics may become an issue as the hybrid suite is most often delocalized. In addition, many procedures realized in a hybrid suite require a multidisciplinary approach and therefore teamwork and professional communication are mandatory. Anesthesiologists need to have an integral role in the hybrid suite team, understanding and anticipating the risks for patients and leading the organization of workflow. The challenge in anesthesia is to ensure that when patients are taken to these complex environments the resources available enable high standards of care to be provided. With future developments in imaging technology combined with more powerful hardware and software, a far greater integration of all these imaging and navigation technologies will be seen in future operating rooms. Finally, patients are becoming more aware of medical developments via the world wide web and increasingly request what they consider to be state of the art treatment.

Recent Update of Endovascular Type 2 Endoleak Management

EVAR has been used clinically for almost three decades, and it has been widely applied in clinical practice and has been applied to difficult cases as devices and techniques have evolved. Although the major advantage of EVAR is its lower perioperative mortality, compared with open surgery, late-onset complications such as endoleaks have become major issues, requiring lifelong follow-up after EVAR. The clinical guidelines have been updated, and many systematic reviews/meta-analyses and multi-center registries have been published; surgeons must keep up-to-date regarding these changes. In this review, the author reviews evidence on the recent update of the type 2 endoleak management.

Editor's Choice - Endovascular vs. Open Repair for Abdominal Aortic Aneurysm: Systematic Review and Meta-analysis of Updated Peri-operative and Long Term Data of Randomised Controlled Trials

OBJECTIVE

The objective was to investigate whether endovascular aneurysm repair (EVAR) has better peri-operative and late clinical outcomes than open repair for non-ruptured abdominal aortic aneurysm.

METHODS

Electronic bibliographic sources (MEDLINE, EMBASE, and CENTRAL) were searched up to July 2019 using a combination of thesaurus and free text terms to identify randomised controlled trials (RCTs) comparing the outcomes of EVAR and open repair. The systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Pooled estimates of dichotomous outcomes were calculated using odds ratio (OR) or risk difference (RD) and 95% confidence interval (CI). A time to event data meta-analysis was performed using the inverse variance method and the results were reported as summary hazard ratio (HR) and 95% CI.

RESULTS

Seven RCTs reporting a total of 2 983 patients were included in quantitative synthesis. Three of the trials reported long term follow up that extended to 15.8 years, 14.2 years, and 12.5 years. Meta-analysis found significantly lower odds of 30 day (OR, 0.36; 95% CI 0.20-0.66) and in hospital mortality with EVAR (RD -0.03; 95% CI -0.04 to -0.02). Meta-analysis of the three trials reporting long term follow up found no significant difference in all cause mortality at any time between EVAR and open repair (HR 1.02; 95% CI 0.93-1.13; p = .62). The hazard of all cause (HR 0.62; 95% CI 0.42-0.91) and aneurysm related death within six months (HR 0.42; 95% CI 0.24-0.75) was significantly lower in patients who underwent EVAR, but with further follow up, the pooled hazard estimate moved in favour of open surgery; in the long term (>8 years) the hazard of aneurysm related mortality was significantly higher after EVAR (HR 5.12; 95% CI 1.59-16.44). The risk of secondary intervention (HR 2.13; 95% CI 1.69-2.68), aneurysm rupture (OR, 5.08; 95% CI 1.11-23.31), and death due to rupture (OR, 3.57; 95% CI 1.87-6.80) was significantly higher after EVAR, but the risk of death due to cancer was not significantly different between EVAR and open repair (OR, 1.03; 95% CI 0.84-1.25).

CONCLUSION

Compared with open surgery, EVAR results in a better outcome during the first six months but carries an increased risk of aneurysm related mortality after eight years.

Aneurysm Sac Thrombus Volume Predicts Aneurysm Expansion with Type II Endoleak After Endovascular Aneurysm Repair

BACKGROUND

Several studies have analyzed risk factors that may influence the incidence of type II endoleak with sac expansion after endovascular aneurysm repair (EVAR). However, the impact of intraluminal thrombus volume on the incidence of sac expansion with type II endoleak requires further analysis. This study examined the correlation between preoperative intraluminal thrombus and the incidence of type II endoleak and late sac expansion by measuring the thrombus volume.

METHODS

Between June 2007 and March 2014, 423 patients underwent EVAR at our institution. Two hundred and eighty patients with preoperative and postoperative computed tomography angiography (CTA) were included in this study. Data were collected prospectively and supplemented with a retrospective review of the medical records and radiologic images, and demographic and clinical characteristic profiles were collected. Logistic regression and Cox regression analyses were used to assess each variable's association with the incidences of persistent or new endoleak and sac expansion.

RESULTS

Of the 280 patients, 46.7% (131 patients) had persistent type II endoleak, and 19.6% (55 patients) had persistent type II endoleak with significant sac expansion (≥5 mm). The mean follow-up duration was 60 months (interquartile range, 24-72 months). Cox regression analysis showed that older age (P = 0.001), intraluminal thrombus volume ratio (thrombus volume [T vol]/aortic aneurysm volume [A vol]) (P = 0.042) and IMA diameter (P = 0.004) were significant predictors of the incidence of sac expansion with persistent or new type II endoleak. The receiver operating characteristic curve analysis revealed a cutoff of 51% T vol/A vol (area under the curve [AUC]: 0.59) and 2.9 mm (area under the curve [AUC]: 0.60). The rate of freedom from sac expansion (≥5 mm) during followup was significantly higher in patients with ≥51% T vol/A vol than in those with a lower T vol/A vol (P = 0.010).

CONCLUSIONS

Preoperative sac thrombus volume, IMA diameter, and older age predict the incidence of aneurysm expansion with type II endoleak after EVAR.

Aortic sac enlargement after endovascular aneurysm repair: volume-related changes and the impact of intraluminal thrombus

PURPOSE

Abdominal aortic aneurysm (AAA) growth after endovascular aneurysm repair (EVAR) is still unpredictable. The issue of optimal frequency of computed tomography angiography for surveillance and its measurement method accuracy remain unclear. We aimed to assess the value of abdominal aneurysm sac volume measurement for detecting expansions and the association of preprocedural intraluminal thrombus (ILT) volume with aneurysm sac growth following EVAR.

MATERIAL AND METHODS

A total of 107 patients underwent elective EVAR. Inclusion criteria provided a cohort of 39 patients. Changes of postoperative maximum aneurysm sac diameter and AAA volume were calculated. Volumetric AAA changes and demographic data of the cases with clinically irrelevant AAA diameter enlargement were evaluated. Preoperative ILT volumes were collected. ILT and AAA sac volume ratio was calculated. Statistical data analysis was performed using standard methods.

RESULTS

The mean changes of maximum AAA diameter and volume in percentage after EVAR were -5.08 ± 8.20 mm and -13.39 ± 23.32%, respectively. A moderate positive linear correlation between those changes was found (R 2 = 0.731; p < 0.0001). The mean relative AAA volume increase in cases without clinically relevant diameter enlargement was 11.50 ± 8.27%. The means of ILT and AAA sac ratios were 0.59 ± 0.17 and 0.52 ± 1.8 in growing AAA sac and in stable or shrinking AAA sac groups, respectively (p = 0.308).

CONCLUSIONS

Volumetric AAA measurement may be useful as an additional method to diameter measurement after EVAR to identify clinically relevant sac growth. Preoperative volume of ILT may not significantly affect the growth rate of AAA after EVAR.

Outcomes after endovascular versus open thoracoabdominal aortic aneurysm repair: A population-based study

OBJECTIVE

We sought to determine the early and late outcomes of endovascular versus open thoracoabdominal aortic aneurysm repair.

METHODS

We performed a multicenter population-based study across the province of Ontario, Canada, from 2006 to 2017. The primary end point was mortality. Secondary end points were time to first event of a composite of mortality, permanent spinal cord injury, permanent dialysis, and stroke, the individual end points of the composite, patient disposition at discharge, hospital length of stay, myocardial infarction, and secondary procedures at follow-up.

RESULTS

A total of 664 adults undergoing surgical repair of a thoracoabdominal aortic aneurysm (endovascular: n = 303 [45.5%] vs open: n = 361 [54.5%]) were identified using an algorithm of administrative codes validated against the operative records. Propensity score matching resulted in 241 patient pairs. Endovascular repairs increased during the study and currently comprise more than 50% of total repairs. In the matched sample, open repair was associated with a higher incidence of in-hospital death (17.4% vs 10.8%, P = .04), complications (26.1% vs 17.4%, P = .02), discharge to rehabilitation facilities (18.7% vs 10.0%, P = .02), and longer length of stay (12 [7-21] vs 6 [3-13] days, P < .01). Long-term mortality was not significantly different (hazard ratio, 1.09; 95% confidence interval, 0.78-1.50), nor were the other secondary end points, with the exception of secondary procedures, which were higher in the endovascular group (hazard ratio, 2.64; 95% confidence interval, 1.54-4.55). At 8 years, overall survival was 41.3% versus 44.6% after endovascular and open repair (P = .62).

CONCLUSIONS

Endovascular repair was associated with improved early outcomes but higher rates of secondary procedures after discharge. Long-term survival after thoracoabdominal aortic aneurysm repair is poor and independent of repair technique.

Long noncoding RNAs in key cellular processes involved in aortic aneurysms

Aortic aneurysm (AA) is a complex and dangerous vascular disease, featuring progressive and irreversible vessel dilatation. AA is typically detected either by screening, or identified incidentally through imaging studies. To date, no effective pharmacological therapies have been identified for clinical AA management, and either endovascular repair or open surgery remains the only option capable of preventing aneurysm rupture. In recent years, multiple research groups have endeavored to both identify noncoding RNAs and to clarify their function in vascular diseases, including aneurysmal pathologies. Notably, the molecular roles of noncoding RNAs in AA development appear to vary significantly between thoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs). Some microRNAs (miRNA - a non-coding RNA subspecies) appear to contribute to AA pathophysiology, with some showing major potential for use as biomarkers or as therapeutic targets. Studies of long noncoding RNAs (lncRNAs) are more limited, and their specific contributions to disease development and progression largely remain unexplored. This review aims to summarize and discuss the most current data on lncRNAs and their mediation of AA pathophysiology.

•

This current review covers studies that have identified long non-coding RNAs in aortic aneurysm development and progression.

•

We separately discuss transcripts and mechanisms of importance to thoracic as well as abdominal aortic aneurysms.

•

Functional data on lncRNAs being identified are highlighted.

•

Some have been studied in human as well as experimental models of the disease pathology.

Long-term survival after endovascular and open repair of unruptured abdominal aortic aneurysm

Background

The aim of this study was to examine patterns of 10-year survival after elective repair of unruptured abdominal aortic aneurysms (AAAs) in different patient groups.

Methods

Patients having open repair or endovascular aneurysm repair (EVAR) in the English National Health Service between January 2006 and December 2015 were identified from Hospital Episode Statistics data. Postoperative survival among patients of different age and Royal College of Surgeons of England (RCS) modified Charlson co-morbidity score profiles were analysed using flexible parametric survival models. The relationship between patient characteristics and risk of rupture after repair was also analysed.

Results

Some 37 138 patients underwent elective AAA repair, of which 15 523 were open and 21 615 were endovascular. The 10-year mortality rate was 38·1 per cent for patients aged under 70 years, and the survival trajectories for open repair and EVAR were similar when patients had no RCS-modified Charlson co-morbidity. Among older patients or those with co-morbidity, the 10-year mortality rate rose, exceeding 70 per cent for patients aged 80 years. Mean survival times over 10 years for open repair and EVAR were often similar in subgroups of older and more co-morbid patients, but their survival trajectories became increasingly dissimilar, with open repair showing greater short-term risk within 6 months but lower 10-year mortality rates. The risk of rupture over 9 years was 3·4 per cent for EVAR and 0·9 per cent for open repair, and was weakly associated with patient factors.

Conclusion

Long-term survival patterns after elective open repair and EVAR for unruptured AAA vary markedly across patients with different age and co-morbidity profiles.

Strength of public preferences for endovascular or open aortic aneurysm repair

Background

This study evaluated public preferences for the treatment processes for abdominal aortic aneurysm repair in order to allow them to be incorporated into a cost-effectiveness analysis.

Methods

This was a telephone survey using a trade-off method in UK resident adults (aged at least 18 years) with no previous diagnosis of a vascular condition.

Results

Some 167 of 209 participants (79·9 per cent) stated that they would prefer endovascular aneurysm repair (EVAR), 40 (19·1 per cent) preferred open surgery and two (1·0 per cent) stated no preference. Participants preferred EVAR because of the less invasive nature of the intervention and quicker recovery. Participants preferring open surgery cited reasons such as having a single follow-up appointment, and a procedure that felt more permanent. When participants were asked to make a sacrifice in order to have their preferred treatment, 122 (58·4 per cent) favoured EVAR, 18 (8·6 per cent) favoured open surgery and 69 (33·0 per cent) had no preference. Those preferring EVAR were willing to give up a mean of 0·135 expected quality-adjusted life-years (QALYs) to have EVAR, compared with a willingness to give up 0·033 expected QALYs among those preferring open repair.

Conclusion

These results indicate a clear preference for EVAR over open surgery for aortic aneurysm.

Shared decision making for elective abdominal aortic aneurysm surgery

Decisions on how and when to treat an abdominal aortic aneurysm involve a number of clinicians; interventional radiologists and vascular surgeons assess the technical ability to repair the aneurysm. Patients' fitness and past medical history is assessed to estimate their short- and long-term survival with or without surgery. Most importantly the patients' personal preference for treatment must be identified. Getting a patient to share what matters most to them requires shared decision making.

Inferior Mid-term Durability with Comparable Survival for Younger Patients Undergoing Elective Endovascular Infrarenal versus Open Abdominal Aortic Aneurysm Repair

BACKGROUND

The durability of endovascular aneurysm repair (EVAR) when compared to open surgical repair (OSR) in younger patients for elective, infrarenal abdominal aortic aneurysms (AAA) remains unclear due to limited follow-up.

METHODS

We identified all patients <70 years of age who underwent elective, de novo EVAR or OSR for infrarenal AAA from 2003 to 2013 in a multihospital, single institution. Baseline patient clinical and aneurysmal characteristics were adjusted for using multivariable Cox proportional hazards models and negative binomial regression.

RESULTS

We identified 253 patients: 204 underwent EVAR (80.6%) and 49 OSR (19.4%). Baseline demographics and comorbidities were similar across groups. There were no deaths in the immediate perioperative period. The rate of new arrhythmia (EVAR: 1.0%, OSR: 10.2%; P = 0.004), median hospital length of stay (EVAR: 1 day, OSR: 5 days; P < 0.001), and discharge to a facility (EVAR: 2.9%, OSR: 12.2%; P = 0.016) were significantly increased for OSR. In both groups, median follow-up time was 4.5 years, in which survival did not differ between groups. The hazard of composite of freedom from death and any reinterventions (hazard ratio [HR] 4.3, P = 0.009), freedom from any reintervention (relative risk [RR] 4.08, P = 0.030), and freedom from any endovascular reintervention (RR 4.83, P = 0.038) were each higher for OSR when compared to EVAR. EVAR of the standard instruction for use (IFU) for neck length was more likely to die or undergo a reintervention (HR 4.90, P = 0.001).

CONCLUSIONS

Our retrospective review of younger patients undergoing elective AAA repair demonstrated no significant differences in perioperative mortality or survival over time between EVAR and OSR. EVAR required more total reinterventions and endovascular reintervention when compared to OSR.

Anaerobic threshold as an independent predictor of mid-term survival following elective endovascular repair of abdominal aortic aneurysm

BACKGROUND

The aim of this study was to examine the value preoperative AT as predictor of postoperative survival in patients who underwent elective EVAR for repair of asymptomatic AAA.

METHODS

Consecutive patients who underwent elective EVAR between 2008 and 2018 were analyzed. Cardiopulmonary exercise testing was performed. Perioperative 30-day mortality was compared between patients who had AT ≥8 mL/kg/min and those with AT<8 mL/kg/min. Risk factors for postoperative survival following EVAR were examined using Cox's regression analysis.

RESULTS

Between 1^st January 2008 and 31^st December 2017, 430 patients underwent elective EVAR (standard device: N.=374, fenestrated/branched: N.=56); their median age was 76 years (range: 53-91 years), median AT was 9.3 (range: 5.4-16.1), and 30-day mortality was 0.9%. These patients were followed up for a median of 1630 days. There was no significant difference in perioperative 30-day mortality between patients who had AT≥8 and those who had AT<8 (χ²=1.56, P=0.22). Age (HR=1.51 [CI: 1.07-1.99], P<0.05) and AT (HR=0.59 [CI: 0.45-0.76], P=0.0003) were predictors of reduced postoperative survival following elective EVAR whereas gender (HR=0.75 [CI: 0.4-1.4], P=0.37), AAA diameter (HR=0.95 [CI: 0.77-1.16], P=0.6), and AAA morphology (HR=1.23 [CI: 0.68-1.76], P=0.95) were not.

CONCLUSIONS

Anaerobic threshold is an independent predictor of prolonged survival following elective EVAR and can be used to identify patients who receive most benefit from elective EVAR.

Effect of Endovascular Treatment Rate on Population Level Outcomes and Survival After Intact Abdominal Aortic Aneurysm Repair

OBJECTIVES

The aim was to study outcomes of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) in four geographically adjacent populations with identical demographics and variable EVAR rates.

METHODS

This was a multicentre cohort study based on local and national registry data from an area of 815 000 inhabitants. The study involved 527 consecutive patients with an intact AAA treated with EVAR (n = 327) or OSR (n = 200) between 2010 and 2016. The catchment area was divided into four health care districts (populations A, B, C, and D) with one central hospital in each district. Each hospital decided independently between OSR and EVAR for patients within their population; OSR was performed in all hospitals while EVAR was centralised in one of them. Patient demographics and treatment outcomes were extracted from local registries. Population demographics, overall AAA incidence, and mortality data were retrieved from a national database.

RESULTS

The rate of new intact AAA diagnosis varied between 20 and 29 per 100 000 inhabitants/year with the highest incidence in population D (p < .001). The intact AAA repair rates were 9.8, 8.9, 9.9, and 8.7 per 100 000 inhabitants/year for populations A, B, C, and D, respectively (p = .64). There were no significant differences in mean age (73.6 ± 8.0 years) or mean aortic diameter (62 ± 13 mm) between the treated patient populations. Groups A and B had high EVAR rates (74% and 72%, respectively) whereas the EVAR rates were lower in groups C and D (50% and 38%, respectively) (p < .001). The 30 day mortality rates were 2%, 2%, 4%, and 1% (p = .55), and complication rates were 17%, 12%, 15%, and 11% (p = .39) for A, B, C and D, respectively. There were no significant differences in mortality, complication or re-intervention rates between the groups during the mean follow up of 3.3 ± 2.0 years.

CONCLUSIONS

At population level, high EVAR rates had no measurable effect compared with lower EVAR rates on the outcomes in patients with intact AAA.

Techniques and future perspectives for the prevention and treatment of endoleaks after endovascular repair of abdominal aortic aneurysms

The presence of endoleaks remains one of the main drawbacks of endovascular repair of abdominal aortic aneurysms leading to the increase of the size of the aneurysmal sac and in most of the cases to repeated interventions. A variety of devices and percutaneous techniques have been developed so far to prevent and treat this phenomenon, including sealing of the aneurysmal sac, endovascular embolisation, and direct sac puncture. The aim of this review is to analyse the indications, the effectiveness, and the future perspectives for the prevention and treatment of endoleaks after endovascular repair of abdominal aortic aneurysms.

In-stent graft helical flow intensity reduces the risk of migration after endovascular aortic repair

During the last years endovascular aneurysm repair (EVAR) became the elective treatment for abdominal aortic aneurysms (AAAs) thanks to lower mortality and morbidity rates than open surgery. In face of these advantages, stent-graft performances are still clinically suboptimal. In particular, post-surgical complications derive from device migration as a consequence of the hemodynamic forces acting on the endograft. In this regard, while the importance of hemodynamic surface forces is well recognized, the role of the in-stent flow is still unclear. Here we hypothesize that in-stent helical blood flow patterns might influence the distribution of the displacement forces (DFs) acting on the stent-graft and, ultimately, the risk of stent migration. To test this hypothesis, the hemodynamics of 20 post-EVAR models of patients treated with two different commercial endografts was analyzed using computational hemodynamics. The main findings of the study indicate that: (1) helical flow intensity decreases the risk of endograft migration, as given by an inverse correlation between helicity intensity (h₂) and time-averaged displacement forces (TADFs) (p < 0.05); (2) unbalanced counter-rotating helical structures in the legs of the device contribute, in particular along the systole, to significantly suppress TADFs (p < 0.01); (3) as expected, helical flow intensity is positively correlated with pressure drop and resistance to flow (p < 0.001). The findings of this study suggest that a design strategy promoting in-stent helical flow structures could contribute to minimize the risk of migration of implanted EVAR devices.

Intra-arterial catheter-directed CT angiography for assessment of endovascular aortic aneurysm repair

OBJECTIVE

To compare the efficacy and safety as well as associated image quality of catheter-directed CT angiography (CCTA) with a low dose of iodine contrast agent compared to intravenous CTA in patients undergoing endovascular aortic aneurysm repair (EVAR).

METHODS

Retrospective data analysis of 92 patients undergoing EVAR between January 2009 and December 2017 was performed. Patients were divided in two groups; those receiving CTA (n = 59) after intravenous contrast agent application and those receiving CCTA (n = 33) via an intraarterial catheter placed in the descending aorta. Demographic and cardiovascular risk factors as well as renal function parameters before, immediately after and 6-60 months after EVAR were evaluated. As primary endpoint, changes in serum creatinine levels in the two groups were evaluated. Secondary endpoints encompassed complications associated with intraarterial catheter placement. Objective (signal-to-noise ratios) and subjective image quality (5-point Likert scale) were compared.

RESULTS

Amount of contrast medium was significantly lower in CCTA compared to i.v. CTA (23 ± 7 ml vs. 119 ± 15 ml, p<0.0001). Patients undergoing catheter-directed CTA had higher baseline creatinine values compared to the group with intravenous iodine application (1.9 ± 0.6 mg/dl vs. 1.3 ± 0.5 mg/dl; p<0.0001). Follow-up serum creatinine levels however did not show significant alterations between the two groups (1.9 ± 0.4 mg/dl vs. 1.3 ± 0.5 mg/dl). No major complications were detected in the CCTA group. Signal-to-noise ratio (SNR) was comparable between i.v. CTA and CCTA (8.5 ± 4.6 vs. 7.7 ± 4.0; p = 0.37) and subjective image similarly revealed no differences with a good interobserver agreement (ICC = 0.647).

CONCLUSIONS

Catheter-directed CTA is safe and provides comparable image quality with a substantial retrenchment of the needed amount of iodine-based contrast medium. However, no benefit of the reduced contrast medium protocol with respect to renal function was observed.

Long-term freedom from aneurysm-related mortality remains favorable after endovascular abdominal aortic aneurysm repair in a 15-year multicenter registry

OBJECTIVE

Endovascular aneurysm repair (EVAR) has become the preferred approach to abdominal aortic aneurysm (AAA) because of lower early morbidity and mortality than open repair. However, the ability of EVAR to prevent long-term aneurysm-related mortality (ARM) has been questioned in light of recent trial data. We have updated our long-term EVAR experience in a large multicenter registry to further examine this issue.

METHODS

Between 2000 and 2010, 1736 patients with AAA underwent EVAR in a large integrated regional healthcare system. We extended follow-up in this previously reported cohort through 2015 and identified predictors associated with ARM and need for major reintervention. The primary outcome was ARM. Secondary outcomes were all-cause mortality, delayed aneurysm rupture, major adverse event, major reintervention, sac growth of more than 5 mm, and type I or III endoleak. End points were analyzed for the whole cohort and compared for patients who underwent EVAR during the earlier (2000-2005) and latter (2006-2010) halves of the enrollment period to assess for changes in outcomes over time of repair.

RESULTS

The overall follow-up rate was 96.3%, and median follow-up was 5.5 years (interquartile range, 2.8-7.7 years). During the study period, 958 patients died, of whom 63 experienced ARM (6.6%). Overall crude rate of freedom from ARM was 96.4%. Delayed aneurysm rupture was seen in 1.3% (n = 23), with a median time to event of 4.1 years (interquartile range, 1.7-7.2 years). Major adverse events occurred in 12.4% of patients, and major reintervention was performed in 10.3%. Overall freedom from major adverse event or major reintervention was seen in 84.0%. Significant predictors of ARM included female sex, age 80 to 89 years, urgent EVAR, and any major reintervention. The unadjusted cumulative probability of all-cause survival was significantly higher in the late group than the early group at 5 years (66.8% vs 59.8%; P = .01, log-rank test); however, freedom from ARM at 5 years was not significantly different (96.5% and 97.1%, respectively; P = .67, log-rank test).

CONCLUSIONS

Our results demonstrate favorable long-term freedom from major adverse event or major reintervention after EVAR and extremely low rates of ARM and delayed rupture. Our findings support EVAR as a safe, long-term solution for managing patients with AAA and provide insight into clinical parameters that can be used to stratify patients' post-EVAR surveillance and need for reintervention.