Abdominal Aortic Aneurysm Sac Research Articles

Design and Characterisation of a Read-Out System for Wireless Monitoring of a Novel Implantable Sensor for Abdominal Aortic Aneurysm Monitoring.

Abdominal aortic aneurysm (AAA) is a dilation of the aorta artery larger than its normal diameter (>3 cm). Endovascular aneurysm repair (EVAR) is a minimally invasive treatment option that involves the placement of a graft in the aneurysmal portion of the aorta artery. This treatment requires multiple follow-ups with medical imaging, which is expensive, time-consuming, and resource-demanding for healthcare systems. An alternative solution is the use of wireless implantable sensors (WIMSs) to monitor the growth of the aneurysm. A WIMS capable of monitoring aneurysm size longitudinally could serve as an alternative monitoring approach for post-EVAR patients. This study has developed and characterised a three-coil inductive read-out system to detect variations in the resonance frequency of the novel Z-shaped WIMS implanted within the AAA sac. Specifically, the spacing between the transmitter and the repeater inductors was optimised to maximise the detection of the sensor by the transmitter inductor. Moreover, an experimental evaluation was also performed for different orientations of the transmitter coil with reference to the WIMS. Finally, the FDA-approved material nitinol was used to develop the WIMS, the transmitter, and repeater inductors as a proof of concept for further studies. The findings of the characterisation from the air medium suggest that the read-out system can detect the WIMS up to 5 cm, regardless of the orientation of the Z-shape WIMS, with the detection range increasing as the orientation approaches 0°. This study provides sufficient evidence that the proposed WIMS and the read-out system can be used for AAA expansion over time.

Transarterial Embolisation of Abdominal Aortic Type II Endoleaks Accessed via the Deep Circumflex Iliac Artery: A Case Series and Literature Review.

We report our technique and experience treating 3 patients with native abdominal aortic aneurysm (AAA) sac expansion following EVAR, who were managed with transarterial embolisation via the deep circumflex iliac artery (DCIA). In this case series, we demonstrate that transarterial embolisation via the DCIA is a feasible and safe treatment option. The DCIA should be routinely interrogated with angiography as not only a cause of possible Type II endoleak, but also to identify a potential access route to the abdominal aortic sac for interventional treatment.

The impact of increasing saline flush volume to reduce the amount of residual air in the delivery system of aortic prostheses-a randomized controlled trial.

Air embolism is a known risk during thoracic endovascular aortic repair (TEVAR) and is associated with an incomplete deairing of the delivery system despite the saline lavage recommended by the instructions for use (IFU). As the delivery systems are identical and residual air remains frequently in the abdominal aortic aneurysm sac, endovascular aortic repair (EVAR) can be used to examine the effectiveness of deairing maneuvers. We aimed to evaluate whether increasing the flush volume can result in a more complete deairing. Patients undergoing EVAR were randomly assigned according to flushing volume (Group A, 1× IFU; Group B, 4× IFU). The Terumo Aortic Anaconda and Treo and Cook Zenith Alpha Abdominal stent grafts were randomly implanted in equal distribution (10-10-10). The quantity of air trapped in the aneurysm sac was measured using a pre-discharge computed tomography angiography (CTA). Thirty patients were enrolled and equally distributed between the two groups, with no differences observed in any demographic or anatomical factors. The presence of air was less frequent in Group A compared to that in Group B [7 (47%) vs. 13 (87%), p = .02], and the air volume was less in Group A compared to that in Group B (103.5 ± 210.4 vs. 175.5 ± 175.0 mm3, p = .04). Additionally, the volume of trapped air was higher with the Anaconda graft type (p = .025). These findings suggest that increased flushing volume is associated with a higher amount of trapped air; thus, following the IFU might be associated with a reduced risk of air embolization. Furthermore, significant differences were identified between devices in terms of the amount of trapped air. [NCT04909190], [ClinicalTrials.gov].

Long Term Outcomes of the Gore Excluder Low Permeability Endoprosthesis for the Treatment of Infrarenal Aortic Aneurysms

This study evaluated the long term outcomes of endovascular aneurysm repair using the Gore Excluder Low Permeability (LP) endoprosthesis across high volume Dutch hospitals. A retrospective analysis was conducted of patients treated with the Excluder LP for infrarenal abdominal aortic aneurysm (AAA) in four hospitals between 2004 - 2017. Primary outcomes were overall survival, freedom from re-interventions (overall, inside/outside instructions for use, IFU), and AAA sac dynamics: growth (> 5 mm), stabilisation, and regression (< 5 mm). Secondary outcomes were technical success (device deployment), procedural parameters, and re-interventions. Follow up visits were extracted from patient files, with imaging assessed for complications and AAA diameter. A total of 514 patients were enrolled, with a median (IQR) follow up of 5.0 (2.9, 6.9) years. Survival rates were 94.0% at 1 year, 73.0% at 5 years, and 37.0% at 10 years of follow up, with freedom from re-interventions of 89.0%, 79.0%, and 71.0%, respectively. Treatment outside IFU was 37.9%, leading to significantly more re-interventions over 10 years compared with inside IFU (36.0% vs. 25.0%, respectively; p = .044). The aneurysm sac regressed by 53.5% at 1 year, 65.8% at 5 years, and 77.8% at 10 years, and grew by 9.8%, 14.3%, and 22.2%, respectively. Patients with 1 year sac growth had significantly worse survival (p = .047). Seven patients (1.4%) had a ruptured aneurysm during follow up. Over 15 years, endoleak type 1a occurred in 5.3%, type 1b in 3.1%, type 3 in 1.9%, type 4 in 0.2%, and type 2 in 35.6% of patients. This multicentre study of real-world endovascular aneurysm repair data utilising the Gore Excluder LP endoprosthesis demonstrated robust long term survival and re-intervention rates, despite 37.9% of patients being treated outside IFU, with type 4 endoleak being rare. Treatment outside IFU significantly increased re-intervention rates and 1 year sac growth was associated with statistically significantly worse survival.

Targeted proteomics and metabolomics for biomarker discovery in abdominal aortic aneurysm and post-EVAR sac volume

Background and aimsAbdominal aortic aneurysm (AAA) patients undergo uniform surveillance programs both leading up to, and following surgery. Circulating biomarkers could play a pivotal role in individualizing surveillance. We applied a multi-omics approach to identify relevant biomarkers and gain pathophysiological insights. Materials and methodsIn this cross-sectional study, 108 AAA patients and 200 post-endovascular aneurysm repair (post-EVAR) patients were separately investigated. We performed partial least squares regression and ingenuity pathway analysis on circulating concentrations of 96 proteins (92 Olink Cardiovascular-III panel, 4 ELISA-assays) and 199 metabolites (measured by LC-TQMS), and their associations with CT-based AAA/sac volume. ResultsThe median (25th-75th percentile) maximal diameter was 50.0 mm (46.0, 53.0) in the AAA group, and 55.4 mm (45.0, 64.2) in the post-EVAR group. Correcting for clinical characteristics in AAA patients, the aneurysm volume Z-score differed 0.068 (95 %CI: (0.042, 0.093)), 0.066 (0.047, 0.085) and −0.051 (-0.064, -0.038) per Z-score valine, leucine and uPA, respectively. After correcting for clinical characteristics and orthogonalization in the post-EVAR group, the sac volume Z-score differed 0.049 (0.034, 0.063) per Z-score TIMP-4, −0.050 (-0.064, -0.037) per Z-score LDL-receptor, −0.051 (-0.062, -0.040) per Z-score 1-OG/2-OG and −0.056 (-0.066, -0.045) per Z-score 1-LG/2-LG. ConclusionsThe branched-chain amino acids and uPA were related to AAA volume. For post-EVAR patients, LDL-receptor, monoacylglycerols and TIMP-4 are potential biomarkers for sac volume. Additionally, distinct markers for sac change were identified.

Injection of n-Butyl-2-Cyanoacrylate into the Abdominal Aortic Aneurysm Sac during Endovascular Aortic Repair to Prevent Type II Endoleaks Caused by Lumbar Arteries

PurposeTo evaluate midterm results of whether the strategy to occlude target lumbar arteries using n-butyl-2-cyanoacrylate (nBCA) injection during endovascular aneurysm repair (EVAR) reduced the incidence of Type II endoleak (T2EL) after EVAR. Materials and MethodsBetween 2013 and 2020, 187 patients underwent EVAR; 106 in the treatment group received nBCA injection during EVAR, whereas 81 in the historical control group did not. The incidence of T2EL at 7 days, need for reintervention, and post-EVAR aneurysmal shrinkage were compared between the groups. ResultsBetween the treatment group and the control group, significant differences were achieved in the incidence of T2EL (2.8% vs 28.4%; P < .0001) and decreased aneurysmal diameter was observed at 1 year after EVAR (−5.2 vs −3.8 mm; P = .034). In multivariate analysis, nBCA injection (odds ratio [OR], 0.04; P = .001) and younger age (OR, 0.92; P = .036) were significantly associated with a reduced incidence of T2EL. As a possible adverse event associated with nBCA injection, 2 cases of transient lower-limb motor dysfunction (1.9%) were observed. Propensity score analysis revealed that the treatment group had a significantly lower incidence of T2EL than that in the control group (P = .0002) even though there was no difference in the incidence of inferior mesenteric artery coil embolization between the groups. The survival rate without aneurysm sac enlargement (100.0% vs 69.8%; P = .014) and the reintervention-free rate (100.0% vs 63.1%; P = .034) in the treatment group were significantly higher than those in the control group. ConclusionsConcomitant nBCA injection can provide durable EVAR without T2EL, as supported by the avoidance of reintervention associated with aneurysm sac enlargement.

Time Dependent Correlation Between Sac Behaviour and Re-intervention after Endovascular Aneurysm Repair

This study aimed to investigate the correlation between aneurysm sac behaviour and time to re-intervention after endovascular aneurysm repair (EVAR). A retrospective observational cohort study of patients who underwent EVAR at a single centre between January 2008 and November 2011 and who were followed up for a mean of 6.6 ± 2.9 years was conducted. Based on sac appearances on pre-operative imaging and imaging at the end of follow up, patients were stratified into two groups: (1) sac regression; and (2) no sac regression. The no sac regression group was further subdivided into stable sac group and sac expansion group. Sac regression and expansion throughout follow up were defined as a decrease or increase in the abdominal aortic aneurysm sac diameter of ≥ 5 mm compared with the pre-operative size. A Cox proportional hazards model using multiple failure per subject data was used to identify sac behaviour as a predictor of re-intervention free time. Patients with sac regression had a higher probability of freedom from re-intervention compared with those with a stable or expanding aneurysm sac (94%, 57%, and 16% at 12 years, respectively; log rank, p<.001). Mean time to re-intervention was 11.3 years for the sac regression group, 8.8 years for the stable sac group, and 5.0 years for the sac expansion group (p < .001). In the stable sac group, the risk of re-intervention increased sharply six years after EVAR, whereas in the sac expansion group a sharp rise in re-intervention was noted 3.5 years after EVAR, reaching a plateau after year 6. A time dependent correlation between aneurysm sac behaviour and re-intervention was found. Such findings have implications for surveillance strategies.

Initial two-day blood pressure management after endovascular aneurysm repair improves midterm outcomes by reducing the incidence of early type II endoleak

ObjectiveThe aim of this study was to evaluate midterm outcomes of our novel strategy of postoperative initial 2-day blood pressure management (BPM) after endovascular aneurysm repair (EVAR) for the prevention of subsequent type II endoleak (T2EL) in a single-center series. MethodsBetween 2008 and 2014, 137 patients who underwent EVAR for abdominal aortic aneurysm (AAA) were reviewed. Starting from 2013, the mean blood pressure was maintained between 75 and 90 mmHg for the initial 24 hours after EVAR followed by systolic pressure controlled below 120 mmHg during the next 24 hours in the treatment group (n = 76). The incidence of T2EL detected at 7 days, reintervention, and AAA sac diameter up to 5 years after EVAR were compared with those of the control group comprising of 60 consecutive patients who underwent standard EVAR without BPM prior to 2013. ResultsBetween the treatment group and the control group, significant differences were achieved in the incidence of T2EL at 7 days (19.7% vs 40.0%; P = .009), a mean decrease of AAA sac diameter at 1-year (−5.1 ± 4.9 vs −2.2 ± 6.7 mm; P = .013) and 2-year (−5.4 ± 7.7 vs −1.7 ± 10.8 mm; P = .045). In addition, there was a significant decrease in the incidence of T2EL detected at 7 days with the use of the Gore Excluder with 22.7% in the treatment group vs 80.0% in the control group (P < .001), which resulted in a significant decrease in the aneurysm sac diameter up to 4 years after EVAR. Survival rate without AAA sac enlargement at 5 years after EVAR (83.0% vs 70.0%; P = .021) in the treatment group was significantly higher than that of the control group, whereas no significant differences were observed in the freedom rates of reintervention, T2EL-related reintervention, and all-cause mortality between the groups. ConclusionsPostoperative initial 2-day BPM had a preventive effect on AAA sac enlargement until midterm periods, by reducing the incidence of T2EL at 7 days after EVAR. The usage of Gore Excluder under BPM was especially associated with sustained positive effects until the midterm follow-up.

Five Year Post-Endovascular Aneurysm Repair Aneurysm Sac Evolution in the GREAT Registry: an Insight in Diabetics Using Propensity Matched Controls

To assess differences in the five year abdominal aortic aneurysm (AAA) sac regression rate after endovascular aneurysm repair (EVAR) in patients with and without diabetes mellitus (DM). An international prospective registry (Europe, USA, Brazil, Australia, and New Zealand) of patients treated with the GORE EXCLUDER endograft. All scheduled EVARs for infrarenal AAA between 2014 and 2016 with complete five year imaging follow up were included. Emergency procedures, ancillary proximal procedures, and inflammatory and infectious aetiologies were excluded. Descriptive and inferential statistics, and Cox proportional hazards survival models were used. A control group of patients without DM with similar age and comorbidities was selected using propensity scores, matched in a 1:2 scheme. A total of 2 888 patients (86.1% male; mean age 73.5 ± 8 years) was included, of whom 545 (18.9%) had DM. Patients with DM had higher rates of hypertension (89.2% vs. 78.4%), dyslipidaemia (76.0% vs. 60.7%), coronary artery disease (52.3% vs. 37.9%), and chronic renal impairment (20.9% vs. 14.0%) (all p < .001). The mean pre-procedural AAA diameter was 58.1 ± 10 mm. Five years post-EVAR, the type 1A endoleak rate was 1.1% (0.6% DM vs. 1.2% non-DM), the endograft related re-intervention rate was 7.3% (6.2% vs. 7.6%), the major adverse cardiovascular event (MACE) rate was 1.4% (1.1% vs. 1.5%), and aortic related mortality rate was 1.0% (0.6% vs. 1.2%), without statistically significant differences between groups. The overall five year mortality rate was higher in diabetics (36.3% vs. 30.5%; hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.07 - 1.58; p= .001). No statistically significant differences were found in sac regression rate (≥ 5 mm) between diabetics and non-diabetics 70.0% vs. 73.1%; HR 0.88, 95% CI 0.75-1.04; p = .131. These differences remained statistically non-significant after excluding patients performed out of instructions for use (p= .61) and patients with types 1, 2 or 3 endoleaks (p= .39). The paradoxical relationship between DM and AAA does not appear to result in differences in post-EVAR sac regression rates. However, even when controlling for other comorbidities, patients with DM undergoing EVAR may have a higher five year mortality rate.

Intra-Sac Injection of Thrombin During Endovascular Aneurysm Repair to Remedy Type II Endoleak and Promote Sac Shrinkage.

To evaluate the safety and effectiveness of intra-sac thrombin injection to remedy type II endoleaks (T2ELs) during endovascular aneurysm repair (EVAR). 224 cases abdominal aortic aneurysm (AAA) were treated with EVAR. For the 52 cases of intra-operative type II endoleaks and 8 cases of ruptured AAAs, after the grafts were deployed, thrombin was injected into the aneurysm sac through a preset catheter. The occurrence of endoleaks post-EVAR were followed up with by Computed Tomography (CT) angiogram. The diameter and the volume of the aneurysm sac were also measured. Endpoints included incidence of T2ELs, AAA sac shrinkage and re-intervention rate and all-cause mortality. The overall technical success rate was 100%. Fifty-two patients were followed up with for 9-56 (median 24) months. No serious complications were observed during follow-up. The incidence of endoleak was 5.8% (3/52) during follow-up. The maximum diameter of the aneurysm decreased from 61.1 ± 14.2mm to 53.7 ± 10.6mm, 47.9 ± 8.3mm and 43.7 ± 7.2mm (87.9%, 78.4% and 71.5% of pre-EVAR) at the 6-month, 1-year and 2-year follow-up, respectively (P < .05). The volume of the aneurysm sac shrank from 236.2 ± 136.2cm3 to 202.6 ± 114.1cm3, 155.6 ± 68.4cm3 and 129.7 ± 52.4cm3 (85.8%, 65.9%, and 54.9% of pre-EVAR) at the 6-month, 1-year and 2-year follow-up, respectively (P < .05). The rate of various endoleaks was 5.8% (3/52) and the re-intervention rate was 1.9% (1/52) in this research. Clinical outcomes show that intra-sac injection of thrombin during EVAR is safe and may be effective in remedying small amount and low-velocity endoleaks and promoting shrinkage of the aneurysm sac.

Residual Aneurysmal Sac Shrinkage Post-Endovascular Aneurysm Repair: The Role of Preoperative Inflammatory Markers.

In this study, we evaluated the role of preoperative inflammatory markers as Neutrophil-to-Lymphocyte (NLR) and Platelet-to-Lymphocyte (PLR) ratios in relation to post-endovascular aneurysm repair (EVAR) sac shrinkage, which is known to be an important factor for abdominal aortic aneurysm (AAA) healing. This was a single-center retrospective observational study. All patients who underwent the EVAR procedure from January 2017 to December 2020 were eligible for this study. Pre-operative blood samples of all patients admitted were used to calculate NLR and PLR. Sac shrinkage was defined as a decrease of ≥5 mm in the maximal sac diameter. The optimal NLR and PLR cut-offs for aneurysmal sac shrinkage were obtained from ROC curves. Stepwise multivariate analysis was performed in order to identify independent risk and protective factors for the absence of AAA shrinkage. Kaplan-Meier curves were used to evaluate survival rates with respect to the AAA shrinkage. A total of 184 patients were finally enrolled. The mean age was 75.8 ± 8.3 years, and 85.9% were male (158/184). At a mean follow-up of 43 ± 18 months, sac shrinkage was registered in 107 patients (58.1%). No-shrinking AAA patients were more likely to be older, to have a higher level of NLR and PLR, and be an active smoker. Kaplan-Meier curves highlighted a higher rate of survival for shrinking AAA patients with respect to their counterparts (p < 0.03). Multivariate analysis outlined active smoking and NLR as independent risk factors for no-shrinking AAA. Inflammation emerged as a possible causative factor for no-shrinking AAA, playing a role in aneurysmal sac remodeling. This study revealed that inflammatory biomarkers, such as NLR and PLR, can be used as a preoperative index of AAA sac behavior after EVAR procedures.

Complex endoleak treatment after failed endovascular aortic repair

BackgroundEndovascular aneurysm repair (EVAR) has created new possibilities for patients with abdominal aortic aneurysms (AAAs), and in recent years it has become tremendously popular. Use of EVAR in selected groups of patients allows mortality and morbidity to be reduced in comparison to open repair. However, complications such as endoleaks (ELs) can be of great concern and warrant urgent therapy to prevent sac rupture.Case presentationThe case report presents urgent endovascular treatment of a high-risk type IA EL in a polymorbid 68-year-old patient 7 years after primary EVAR. The principle of treatment was parallel implantation of the proximal SG extension with the renal SG into the right renal artery (chimney technique). The subsequent type II collateral EL was treated by direct transabdominal AAA sac puncture and thrombin embolization.ConclusionEL can be a cause for urgent intervention, but specific anatomic features often require specialized SG types which are not readily available. The chimney technique allows the use of immediately available stent grafts to address endoleak in the setting of impending abdominal aneurysm rupture.

Factors associated with all-cause mortality following endovascular abdominal aortic aneurysm repair.

Background: Knowledge of factors that influence all-cause mortality after endovascular abdominal aortic aneurysm repair (EVAR) could improve therapeutic strategies post-EVAR and thus patient prognosis. Our study aimed to evaluate the association between sociodemographic information, comorbidities, laboratory parameters, treatment, selected anatomical and genetic factors and all-cause mortality post-EVAR. Patients and methods: We reviewed all patients who had undergone elective EVAR for non-ruptured abdominal aortic aneurysm (AAA) between January 2010 and December 2019. AAA size (maximum diameter and volume) was measured using CT-angiography. Sac expansion was defined as at least 5 mm increase, sac regression as at least 5 mm decrease in the sac diameter determined at 36±3 months post-EVAR in relation to pre-EVAR AAA diameter. Adjustments were performed for age, hypertension, diabetes mellitus, dyslipidaemia, sex, smoking, number of lumbar arteries, patency of inferior mesenteric artery and number of reinterventions post-EVAR. Results: One hundred and sixty-two patients (150 men, 12 women) with a mean age of 72.6±7.3 years were included in the analysis. Pre-EVAR AAA diameter (HR 1.07; 95% CI 1.03 - 1.12; p=0.001), pre-EVAR AAA volume (HR 1.01; 95% CI 1.002 - 1.011; p=0.008), post-EVAR sac diameter (HR 1.06; 95% CI 1.03 - 1.10; p=0.000), post-EVAR sac volume (HR 1.01; 95% CI 1.002 - 1.011; p=0.006) and anticoagulation therapy (HR 2.46; 95% CI 1.18 - 5.14; p=0.019) were associated with higher mortality in multivariate analysis. Sac regression (HR 0.42; 95% CI 0.22 - 0.82; p=0.011), and treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) (HR 0.71; 95% CI 0.36 - 0.97; p=0.047) were associated with lower mortality. Conclusions: Greater pre- and post-EVAR diameter and volume, failure of sac regression and anticoagulation were associated with higher mortality post-EVAR. Reduced mortality was observed in patients treated with ACE inhibitors or ARBs, and in patients with AAA sac regression.

467-P: Reinterventions after Abdominal Aortic Aneurysm Repair in People with Diabetes Mellitus—A Systematic Review and Meta-analysis

Background: There is a known negative association between diabetes (DM) and abdominal aortic aneurysm (AAA). Patients with DM have a higher long-term mortality following AAA repair. However, whether that is related to their AAA is unclear. Aims: To determine the rates of reinterventions in patients with DM post-AAA repair. Outcomes included; AAA sac enlargement, reinterventions, endoleaks, AAA rupture, and conversion. Methods: Pubmed, Embase and Cochrane databases were searched for primary research studies between 2005 and 2022 according to PRISMA guidelines. Patients undergoing AAA repair either via endovascular aneurysm repair or open surgical repair were included. Meta-analysis was conducted using Review Manager. Results: Eight studies were identified totalling 75678 patients in the control group, and 22284 in the DM group. Patients with DM had a lower rate of reintervention compared to the control group, (6.63% v 9.15%; OR 0.80, 95%CI[0.67, 0.94], P=0.007). There was no significant difference in rate of all endoleaks (8.54% v 12.38%; OR 0.91, 95%CI[0.53-1.58], P=0.74), which remained non-significantly in favour of DM when comparing type 1 and 2 separately, with similar results with sac expansion. There was a significant reduction in rates of conversion to open surgery in those with DM (3.07% v 4.21%; OR 0.75, 95%CI[0.55-0.99], P=0.04), and a reduction in post op AAA rupture (3.35% v 5.69%; OR 0.53, 95%CI[0.49-0.58], P&amp;lt;0.001). Conclusion: Postoperative AAA ruptures, reinterventions, and conversion to open surgery were lower in patients with DM. However, the rates of endoleaks were not significantly different, so the reason for higher complication rates remains unknown. Disclosure K.Dhatariya: Other Relationship; Novo Nordisk, AstraZeneca, Boehringer-Ingelheim, Eli Lilly and Company. E.A.A.Otify: None. M.A.E.Mekki: None. P.W.Stather: None.

Impact of patient demographics and intraoperative characteristics on abdominal aortic aneurysm sac following endovascular repair.

Endovascular aortic repair (EVAR) has become the preferred treatment for abdominal aortic aneurysm (AAA). Its main aim is to seal the perfusion of the aneurysmal sac and, thus, induce sac regression and subsequent aortic remodelling. Aneurysmal sac regression has been linked to the short- and long-term clinical outcomes post-EVAR. It has also been shown to be influenced by endograft device choice, with several of these available commercially. This review summarises and discusses current evidence on the influence of pre- and intraoperative factors on sac regression. Additionally, this review aims to highlight the device-specific variations in sac regression to provide an overall holistic approach to treating AAAs with EVAR. A comprehensive literature search was conducted using multiple electronic databases to identify and extract relevant data. Female sex, >70 mm original sac diameters, higher pre-procedural fibrinogen levels, smoking and low intra-aneurysmal pressure were found to positively impact sac regression. Whereas renal impairment, ischemic heart disease, high intra-aneurysmal pressure and aneurysm neck thrombus negatively influenced sac regression. Patent lumbar arteries, age, statins and hypercholesterolaemia displayed conflicting evidence regarding sac regression. Regarding the EVAR endografts compared, newer generation devices such as the Anaconda mainly showed the most optimal results. Sac regression following EVAR in AAA is an important prognostic factor for morbidity and mortality. Nevertheless, several pre- and intraoperative factors can have an influence on sac regression. Therefore, it is necessary to take them into account when assessing AAA patients for EVAR to optimise outcomes. The choice of EVAR stent-graft can also affect sac regression, with evidence suggesting that the Fenestrated Anaconda is associated with the most favourable results.

Incidence, reintervention, and survival associated with type II endoleak at hospital discharge after elective endovascular aneurysm repair in the Vascular Quality Initiative

BackgroundThe longitudinal clinical significance of type II endoleaks (T2ELs) remains controversial. Specifically, the real-world incidence, need for reintervention, and associated mortality referable to T2ELs remain unknown. Moreover, current professional society clinical practice guidelines recommend differing aneurysm sac growth thresholds to prompt intervention. Therefore, the purpose of this analysis was to better quantify the prevalence of early T2ELs after infrarenal endovascular aortic aneurysm repair (EVAR) and determine its association with reintervention and survival. MethodsAll elective EVARs from the Vascular Quality Initiative (2010-2020) were examined to identify patients with isolated T2ELs vs no endoleak (NONE) at discharge. Procedures with a type I or III endoleak were excluded. A subgroup analysis was performed on patients surviving beyond the first postoperative year with follow-up data available on endoleaks. The primary outcome was overall survival. Secondary outcomes included perioperative mortality and reinterventions. Outcomes were assessed by multivariable logistic and Cox proportional hazards regression to adjust for covariates. ResultsWe identified 53,697 patients who underwent EVAR. The overall incidence of isolated T2ELs at discharge was 16%. In-hospital mortality was lower for those with isolated T2ELs vs NONE (0.8% vs 1.9%, odds ratio: 0.6, 95% confidence interval: 0.5-0.8, P < .0001). Unadjusted overall survival was marginally higher at 5 years for patients with T2ELs vs NONE (84% vs 82%); however, after risk adjustment, survival was similar (hazard ratio: 0.95, 95% confidence interval: 0.9-1.0). Among 44,345 patients with 1-year follow-up, 66% had data on endoleak status for assessment. Survival was similar regardless of endoleak status (NONE, at discharge only, at follow-up only, or at both time points). Among patients with documented T2ELs during follow-up, 6.1% and 2.5% had abdominal aortic aneurysm sac diameter growth ≥5 mm and ≥10 mm, respectively. Reinterventions occurred in 12%. Rupture (1%) and any open reintervention (4%) were rare among patients with 1-year follow-up. For patients with T2ELs, 5-year survival was similar between those with and without reintervention by 1 year (89% vs 91%, log-rank P = .06). ConclusionsT2ELs remain common after EVAR within the Vascular Quality Initiative and are not associated with long-term mortality. Reinterventions for T2ELs were not associated with improved overall survival among patients with T2ELs. Although additional data surrounding the appropriate role of reintervention for T2ELs remain necessary, it appears that the natural history of T2ELs is benign.

Effect of Intraluminal Thrombus Burden on the Risk of Abdominal Aortic Aneurysm Rupture.

Abdominal aortic aneurysm (AAA) is a critical health disorder, where the abdominal aorta dilates more than 50% of its normal diameter. Enlargement in abdominal aorta alters the hemodynamics and flow-induced forces on the AAA wall. Depending on the flow conditions, the hemodynamic forces on the wall may result in excessive mechanical stresses that lead to AAA rupture. The risk of rupture can be predicted using advanced computational techniques such as computational fluid dynamics (CFD) and fluid-structure interaction (FSI). For a reliable rupture risk assessment, formation of intraluminal thrombus (ILT) and uncertainty in arterial material properties should be taken into account, mainly due to the patient-specific differences and unknowns in AAAs. In this study, AAA models are computationally investigated by performing CFD simulations combined with FSI analysis. Various levels of ILT burdens are artificially generated in a realistic AAA geometry, and the peak effective stresses are evaluated to elucidate the effect of material models and ILT formation. The results indicate that increasing the ILT burden leads to lowered effective stresses on the AAA wall. The material properties of the artery and ILT are also effective on the stresses; however, these effects are limited compared to the effect of ILT volume in the AAA sac.

The Implications of Oxygen Dependent Chronic Obstructive Pulmonary Disease On Abdominal Aortic Aneurysm Sac Growth and Mortality Following Endovascular Aortic Aneurysm Repair

Chronic obstructive pulmonary disease (COPD) is a documented risk factor for abdominal aortic aneurysm (AAA) growth and rupture. However, little is known about the impact of COPD on AAA sac behavior after endovascular AAA repair (EVAR). Our objective was to determine the longitudinal association between COPD and sac remodeling after EVAR. All EVAR patients from 2010 to 2021 were identified within the Society of Vascular Surgery-Vascular Quality Initiative. Patients who expired within the first postoperative year or lacked follow-up data were excluded. The primary exposure was COPD severity (none, medically treated, and oxygen-dependent). The primary end point was sac growth after index EVAR. Secondary end points included mortality and reintervention. We used mixed-effects linear and logistic regression to assess the effects of COPD severity on sac remodeling with particular attention to control for the presence of endoleak. Cox-proportional hazards regression identified the predictors of mortality and reintervention. A total of 30,686 EVAR patients met inclusion criteria. The cohort had a mean age of 73 years with 18% female (n = 5519). A total of 24% had documented COPD (none 76% [n = 23,260], medically treated, 20% [n = 6057], oxygen-dependent 4% [n = 1369]), whereas 29% (n = 8803) were active smokers. Persistent sac growth was significantly associated with oxygen-dependent COPD (regression coefficient: +0.55, 95% confidence interval [CI]: 0.046-1.05; P = .03) after EVAR implantation; however, medically treated COPD was not (regression coefficient: −0.06, 95% CI: −0.322 to 0.199; P = .6). Notably, in adjusted analysis, patients with oxygen-dependent COPD did not experience increased reintervention rates (hazard ratio [HR]: 0.88, 95% CI: 0.8-1.02; P = .09), as they were vulnerable to significantly increased mortality (HR: 1.9, 95% CI: 1.74-2.12; P = .01) (Fig). Moreover, mortality was similar among patients irrespective of post-EVAR sac enlargement (HR: 1.2, 95% CI: 0.96-1.4; P = .13). As expected, the incidence of type 2 endoleak was greater among patients with documented sac growth of >5 mm irrespective of COPD severity (26% vs 10%, P < .0001), which also correlated with increased reintervention rates over time (22% vs 4%, P < .0001). Oxygen-dependent COPD was significantly associated with increased sac growth after EVAR. However, patients with oxygen-dependent COPD did not experience increased reinterventions, though this likely reflects the >2-fold risk of mortality within 2 years of their index EVAR. These findings underscore the importance of critical patient selection among those with severe COPD when considering EVAR and justify reserving repair for patients at greatest risk for AAA-related mortality.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 3View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Impact of Abdominal Aortic Aneurysm Sac Shrinkage on All-cause Survival and Long-term Sac Behavior, up to 5 Years After Endovascular Aortic Repair with a Low-profile Device

Impact of Abdominal Aortic Aneurysm Sac Shrinkage on All-cause Survival and Long-term Sac Behavior, up to 5 Years After Endovascular Aortic Repair with a Low-profile Device

Early Results of Elective Endovascular Repair of Infrarenal Abdominal Aortic Aneurysms With the MinosTM Stent-Graft System.

A variety of last-generation endografts are currently available for standard endovascular repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs). The purpose of this study is to report the preliminary clinical outcomes of the Minos trimodular stent-graft system, which was recently introduced to the European market. Between February 2020 and 2022, we treated 41 consecutive AAA patients (mean age 72.2±8.5, 37 males) with elective standard EVAR using the Minos. The mean maximum diameter of AAAs was 54.7±6.6 mm, the mean proximal neck's (PN) diameter was 24.8±2.7 mm, while the relevant length and angulation were 16.0 mm and 21.7°, respectively. Overall, 22 (53.6%) patients presented with shorter and angulated PN, according to the stent-graft's instructions of use, and in 6 (14.6%) patients the PN angulation >60° was combined with concomitant iliac angulation >60°. Eleven (26.8%) EVARs were performed with concomitant enormous iliac artery narrowing and tortuosity. Finally, in 19 (46.3%) AAAs, the distal iliac landing zone was aneurysmatic and they were treated with the bell-bottom technique in 17 patients and with limb extension to the external iliac artery in two cases. We evaluated technical and clinical success of the index procedures, which was based on the combination of five factors: freedom from EVAR-related mortality, from graft-related endoleak of any type, from migration at any part of graft as well the absence of notable increase AAA's sac maximum diameter and the patency of bifurcated stent-graft and of access vessels. Primary technical and clinical success of index procedures was 100%. During a median 12-month radiological follow-up the clinical success remained 100%. No type I or III endoleak, stent-graft migration, EVAR-related death, AAA rupture, or graft-related adverse events or reinterventions were documented. Four (9.8%) type II endoleaks were detected with stable AAA sac diameter. The overall incidence of sac regression was 34.1% (n=14). The preliminary results of our series showed that Minos provided excellent feasibility and safety features even through angulated and tortuous iliac vessels and in short and angulated PNs. The overall clinical success at 1 year suggests that performance of Minos follows very high standards. Further validation of these promising results with long-term data is acquired to complete the evaluation of this recently introduced stent-graft system. The current study explored the clinical performance of a new in market ultra-low profile bifurcated abdominal aortic stent-graft, the MINOS. The early and 12-month results of study suggest that implantation of this stent-graft in standard EVAR, even in hostile proximal aortic neck and iliac vessels conditions, follows very high clinical standards and encourage the further clinical use of MINOS.