Treatment Of Abdominal Aortic Aneurysms Research Articles

Racial and ethnic disparities in abdominal aortic aneurysm evaluation and treatment rates in Texas

BackgroundScreening identifies intact abdominal aortic aneurysms (iAAAs) before progression to ruptured AAAs (rAAAs). However, screening efforts have been limited by the low overall diagnostic yield and unequal screening among minority populations. The goal of the present study was to identify equitable AAA screening strategies for both majority and minority populations. MethodsWe performed epidemiologic and geospatial analyses of inpatient and outpatient procedures for iAAAs and rAAAs at Texas hospitals from 2006 through 2014 at all nonfederal hospitals and clinics in Texas. The data were aggregated by area (metropolitan statistical area vs rural region) and then supplemented by six additional data sources to estimate the AAA repair incidence rates, rates of AAA-related clinic and ultrasound visits, travel distance to providers, and the location and number of unrecognized AAAs. ResultsMost AAA repairs had occurred among men aged 65 to 84 years and categorized as White in large metropolitan areas. The area procedure rates for rAAAs and iAAAs were strongly correlated (R2 = 0.47). Two other variables—the proportions of persons categorized as White and those aged ≥65 years in a region—identified subgroups within the majority population with a high risk of iAAAs (R2 = 0.46). Lower rates of clinic visits and AAA ultrasound scans were seen among persons categorized as Black. Several areas with disproportionately higher rAAA/iAAA repair ratios were found, mainly affecting persons categorized as Black. ConclusionsMultiple focused AAA screening strategies could be required to address the disproportionately lower AAA identification among persons categorized as Black.

The correlation of aortic neck length to late outcomes following EVAR with the Ovation stent graft

ObjectiveEndovascular aneurysm repair (EVAR) performed outside manufacturers’ instructions for use due to short aortic neck for the treatment of abdominal aortic aneurysm (AAA) is associated with unfavorable outcomes. Newer endografts now have an indication for shorter neck aneurysms that previous endografts do not, but this cohort has yet to be evaluated individually. The aim of this study is to evaluate 5-year outcomes after EVAR in patients with short aortic necks (<10 mm) using the Ovation stent graft. MethodsThe study comprised 238 patients who underwent EVAR as part of the prospective international multicenter Ovation stent graft trials. The main inclusion criteria were AAA diameter ≥ 5 cm, proximal parallel neck length ≥7 mm, neck angulation ≤60°, and bilateral iliac fixation length ≥10 mm. A clinical events committee adjudicated adverse events through 1 year, an independent imaging core laboratory analyzed imaging through 5 years, and a data safety and monitoring board provided study oversight. Patients were divided into short neck (<10 mm) and standard neck (≥10 mm) groups. End points included long-term survival, freedom from aneurysm-related mortality (ARM), freedom from type Ia endoleak, and freedom from reintervention. ResultsPatients were predominantly male (81%) with a mean age of 73 ± 8 years. Median follow-up time was 58 months (interquartile range, 36-60 months). Of 238 patients, 41 (17.2%) had a proximal neck length <10 mm and would be considered outside the instructions for use with other stent grafts. Baseline characteristics were relatively similar between the two groups. The 5-year overall survival estimates were 77.8% for the standard neck group compared with 59.5% for the short neck group (P = .03). There were no differences in the 5-year freedom from ARM (99.2% vs 100%; P = .7), freedom from type Ia endoleak (96.3% vs 96.3%; P = .8), and freedom from reintervention (77.9% vs 79.7%; P = .7) between the standard and short neck groups, respectively. After adjusting for age and other potential confounders, short proximal neck was associated with a two-fold increase in 5-year all-cause mortality (adjusted hazard ratio, 2; 95% confidence interval, 1.02-3.8; P = .04]. ConclusionsThe Ovation endograft performed well in short AAA neck with no difference in 5-year type Ia endoleak, reintervention, and ARM rates. However, short proximal neck was independently associated with a two-fold increase in the risk of all-cause mortality at 5 years. These findings confirm the prior literature on the association of hostile neck anatomy with late mortality following EVAR.

One-year results of the INSIGHT study on endovascular treatment of abdominal aortic aneurysms

ObjectiveEndovascular repair of abdominal aortic aneurysms (AAAs) using the INCRAFT AAA Stent Graft System was safe and effective in regulatory approval studies. We herein report on the 1-year results of a real-world clinical study. MethodsThe INSIGHT study is a multi-center, prospective, open label, post-approval study conducted to continually evaluate the safety and performance of the INCRAFT System. Between 2015 and 2016, 150 consecutive patients with AAA at 23 centers in Europe were treated with the device in routine clinical practice. The primary endpoint was freedom from major adverse events (MAEs), namely death, myocardial infarction, cerebrovascular accident, and renal failure, within 30 days of the index procedure. End point data were assessed by a core laboratory. The secondary end points included technical success at the conclusion of the procedure and clinical success. ResultsAll 150 patients studied (mean age, 73.6 ± 8.0 years; 89.3% men) met the primary end point without MAEs at 30-day follow-up. Technical success was achieved in 99.3% of patients without stent fractures at 30 days. Among the 146 patients eligible for 1-year follow-up, the MAE rate was 8.2% (ie, 12 patients suffered 13 MAEs: cerebrovascular accident in 8, myocardial infarction in 1, and 4 died, resulting in a 2.7% all-cause mortality rate). There were no reports of new onset renal failure requiring dialysis. Only 2.7% of patients had type I endoleak, and no type III endoleaks were identified through 1 year. The rate of clinical success at 1 year was 91.8%. ConclusionsThe 1-year results of this multicenter real-world study underscore the safety and effectiveness of endovascular treatment of AAA with the INCRAFT System in routine clinical practice.

Nationwide Experience with EVAS Relining of Previous Open or Endovascular AAA Treatment in The Netherlands

Relining of a previously placed surgical graft or endograft for an abdominal aortic aneurysm (AAA) is a reintervention to treat progression of disease or failure of the primary (endo)graft. Endovascular Aneurysm Sealing (EVAS) relining is a technique with potential advantages due to the absence of a bifurcation, the possibility for a unilateral approach, and sealing concept of the endobags. The purpose of this study was to describe the nationwide experience with EVAS relining of previous AAA repair in the Netherlands. A retrospective analysis of all patients who underwent EVAS relining in 7 high volume vascular centres in the Netherlands between 2014 and 2019 was performed. Primary outcomes were technical and clinical success. Secondary outcomes were perioperative outcomes, complications and survival. Thirty-three patients underwent EVAS relining of open (n=10) or endovascular (n=23) repair. 26 were elective cases, 5 were urgent and 2 were acute (ruptured). Mean time between primary treatment and EVAS relining was 99 ± 74 months. Indications after open repair were proximal progression of disease (n=7) and graft defect (n=3). Indications after EVAR were type IA (n=10), type IB (n=3), type IIIA (n=4), type IIIB (n=3) endoleak, and endotension (n=3). 18 patients underwent regular EVAS, 4 unilateral EVAS and 11 chimney-EVAS. In-hospital mortality was 6% (both patients with rAAA). Technical success was achieved in 97%. Median follow-up after EVAS relining was 20 months (range 0-43). Freedom from reintervention at 1-year and 2-year were 83% and 61% and the estimated survival 79% and 71%, respectively. EVAS relining after open repair had a clinical success of 90% at 1-year and of 70% at latest follow-up, while after EVAR clinical success rates were 70% and 52%, respectively. EVAS relining of previous AAA repair is associated with high technical success, however with limited clinical success at median follow-up of 20 months. Clinical success was higher in patients with EVAS relining after open repair than after EVAR. In patients with failed AAA repair, EVAS relining should only be considered, when established techniques such as fenestrated repair or open conversion are not available or indicated.

Meta-analysis finds recurrent infection is more common after endovascular than after open repair of infected abdominal aortic aneurysm.

Controversy has continued regarding the use of endovascular aneurysm repair (EVAR) vs open aneurysm repair (OAR) for infected abdominal aortic aneurysms (AAAs). In the present study, we investigated the comparative outcomes of EVAR and OAR for the treatment of infected AAAs. We conducted a systematic review and meta-analysis using the MEDLINE and EMBASE databases through May 2021. We included studies that had described both EVAR and OAR for the treatment of infected AAAs. The primary endpoints were the rates of recurrent infection and related rupture and/or death. Perioperative and 1-year mortality and readmissions and reinterventions were also analyzed. Fourteen observational studies describing a total of 1203 patients (EVAR, 359 [29.8%]; OAR, 844 [70.2%]) were eligible for qualitative analysis. The baseline characteristics included diabetes mellitus (33.2%), fever at presentation (71.6%), rupture at diagnosis (26.1%), and positive blood cultures (52.5%). The mean follow-up period ranged from 12 to 40months. The use of EVAR became more prevalent in recent years (2016-2020, 32.4%) compared with the former period (2010-2015, 13.8%; P< .0001). Fenestrated, branched, or concomitant visceral debranching EVAR was performed in 6.1% of cases. In OAR, surgical debridement was consistently performed, and in situ reconstruction was applied in 82.2% and an omental flap in 51.5%. In nine studies considered for quantitative analysis, the patients' background (EVAR, n= 264; OAR, n= 274) were statistically balanced. The crude rates of recurrent infection and related rupture or death were 13.6% (95% confidence interval [CI], 8.8%-18.5%) and 4.9% (95% CI 1.8%-8.0%), respectively. The pooled analyses depicted significantly higher rates of recurrent infection after EVAR than after OAR (relative risk [RR], 2.42; 95% CI, 1.80-3.27; P< .0001; I2= 0%). Recurrent infection-related rupture or death (RR, 1.51; 95% CI, 0.70-3.23; P= .29; I2= 0%), perioperative death (RR, 0.80; 95% CI, 0.39-1.65; P= .55; I2= 35%), 1-year mortality (hazard ratio, 1.12; 95% CI, 0.97-1.28; P=.13; I2= 0%), and readmission or reintervention (RR, 1.16; 95% CI, 0.74-1.82; P=.52; I2= 0%) were not significantly different statistically between the two groups. Funnel plots showed no evidence of publication bias. Sensitivity analyses of leave-one-out meta-analysis confirmed higher rates of recurrent infection after EVAR. EVAR has become more prevalent as the initial treatment of infected AAAs. Although operative and 1-year survival were similar between OAR and EVAR groups, recurrent infection was more frequent after EVAR. This limitation should be weighed in selecting patients for EVAR in infected AAAs. Postoperative graft and infection surveillance are critical, especially after EVAR.

Treatment of recurrent iliac branch occlusion after endovascular repair of abdominal aortic aneurysm diagnosed by contrast- enhanced ultrasound combined with computed tomography angiography: a case report

Endovascular treatment of abdominal aortic aneurysm (AAA) has been in use for several decades and has become the main treatment for this disease. Iliac branch occlusion (IBO) is a common complication after endovascular treatment. The diagnosis and guidance of contrast-enhanced ultrasound (CEUS) combined with computed tomography angiography (CTA) in the treatment of recurrent IBO after endovascular aneurysm repair (EVAR) are rarely reported. In this case, CEUS gave important hints on the cause of IBO. We present a 67-year-old male patient who was diagnosed with AAA in 2020 and underwent endovascular treatment in the same period. There was no family history of AAA. The operation process was successful. The CTA re-examination one month after operation showed that the aneurysm was well isolated without obvious endoleak. However, the patient developed intermittent claudication of both lower limbs after operation, but did not receive relevant diagnosis and treatment. Four months after surgery, the patient's claudication symptoms of the left lower limb were significantly worse than before, and CTA review revealed left IBO. The left ankle brachial index (ABI) was too low to detect the value. A femoral artery thrombectomy was performed and a stent was extended distal to the left iliac stent. The claudication symptoms improved after surgery. Unfortunately, only two months later, the patient developed rest pain in the left lower limb. CTA examination showed that the left iliac branch was occluded again. The problem in the proximal end of the left iliac branch was observed by CEUS before re-operation, which was also confirmed by digital subtraction angiography (DSA) after thrombectomy. The blood flow was significantly improved after the angle of the proximal iliac branch was adjusted by stent placement. The patient did not show claudication symptoms again during follow-up. Through CEUS, we identified the pathogenic causes which could not be reflected in CTA and formulated the correct treatment plan. The risk factors of IBO after EVAR are mostly hidden in the process of the initial operation. CEUS can provide more information about postoperative hemodynamics than CTA. The role of CEUS in postoperative follow-up of endovascular treatment of AAA needs to be further explored.

Meta-analysis suggests statins reduce mortality after abdominal aortic aneurysm repair.

The necessity and efficacy of statin treatment for abdominal aortic aneurysm (AAA) remains controversial. This systematic review and meta-analysis was conducted to investigate the effects of statin therapy on the outcomes of patients with AAA. The Cochrane library, Embase, and MedLine were searched comprehensively to identify relevant cohort studies and randomized controlled trials. The primary outcomes included short- and long-term mortality after AAA repair, and secondary outcomes included the incidence of perioperative cardiovascular complications, sac shrinkage after endovascular aneurysm repair, and the growth rate of the aneurysms. Short-term mortality was defined as all-cause 30-day or in-hospital postoperative mortality. Long-term mortality was defined as the all-cause mortality at the end of follow-up period (≥1year). A random effects model was used to combine the results of included studies. Forest plots were created to show the pooled results of each outcome. One post hoc analysis of a randomized trial and 36 cohort studies (n= 134,290 patients) were included in this systematic review. The average score of included studies by Newcastle-Ottawa Scale was 7.76. Patients taking or not taking statin therapy were all diagnosed with unruptured AAA, and 59.9% of these patients were given statin therapy. Compared with statin nonusers, patients in statin therapy had significantly lower long-term mortality (odds ratio, 0.67; 95% confidence interval, 0.59-0.75; P< .001; I2= 71.7%), and short-term mortality after aneurysmal repair (odds ratio, 0.51; 95% confidence interval, 0.36-0.73; P< .001; I2= 81.4%). No significant difference was found between patients taking or not taking statin treatment on perioperative cardiovascular complications or sac shrinkage after endovascular aneurysm repair or growth rate of AAA under surveillance. These findings suggest that statin use is associated with a significant decrease in long- and short-term mortality in patients after AAA repair. Based on these results, statin therapy is worth being used in clinical practice for the management of AAA.

Endoleaks in endovacular treatment of infrareneral abdominal aortic aneurysm (part I)

We analyzed the PubMed, Scopus databases and the eLIBRARY electronic library regarding appropriate literature data. In the first part, modern classifications of endoleaks type 1 and 2 after stenting of infrarenal aortic aneurysm are considered. We described causes, risk factors and effectiveness of various treatment options.

Otvoreno hirurško lečenje aneurizmi abdominalne aorte u endovaskularnoj eri

In addition to the well-known benefits, endovascular treatment (EVAR) of abdominal aortic aneurysms has its drawbacks and limitations. That is why open surgery (OS) still has a very important place. OS should be considered as the first treatment option for degenerative AAAs with either favorable or unfavorable anatomy in low-risk patients with long life expectancy. When it comes to inflammatory AAA, OS is indicated only in patients at low risk and hydronephrosis. OS is the "gold standard" for the definitive treatment of mycotic AAAs. In cases of complete thrombosis AAA is the only viable OS. OS is the method of choice in AAA with associated significant accessory renal arteries. OS is the method of choice for the treatment of AAA in patients with connective tissue disorders. Different types of endolic, infection, collapse and stent graft migration, or aneurysmal sac rupture, require late open surgical conversion after EVAR. OS is indicated if patients with RAAA are severely hemodynamically unstable, if they do not have a favorable anatomy, or if they have a large retroperitoneal hematoma. OS AAA can be performed only in centers with a large volume of work by experienced surgeons. The younger generation of vascular surgeons must be educated for both EVAR and OH AAA.

Era of endovascular aortic aneurysm repair is linked to preoperative anatomic severity and perioperative patient outcomes

Varying opinions on optimal elective and emergent surgical management of infrarenal abdominal aortic aneurysms are expressed by the most recent Society for Vascular Surgery (SVS), European Society for Vascular Surgery, vs UK National Institutes for Health and Care Excellence guidelines. The UK National Institutes for Health and Care Excellence guidelines propose that open surgical repair serve as the default treatment for infrarenal abdominal aortic aneurysm. The rationale for this approach relied on data from the early era of endovascular aneurysm repair (EVAR) and are in contrast to the more balanced approaches of the SVS and European Society for Vascular Surgery. We hypothesize that significant differences in patient selection, management, and postoperative outcome are related to the era in which treatment was undertaken, contextualizing the outcomes reported in early-era EVAR randomized controlled trials. Retrospectively, two cohorts representing all EVAR patients from "early" (n= 167; 2008-2010) and "late" (n= 129; 2015-2017) periods at a single treating institution were assembled. Primary outcomes of era-related changes in preoperative demographics, anatomy, and intraoperative events were assessed; anatomy was compared using the SVS anatomic severity grading system. These era-related differences were then placed in the context of early perioperative outcomes and at follow-up to 1year. Choice of surgical strategy differed by era, despite the same patient preoperative comorbidities between EVAR groups. Preoperative anatomic severity was significantly worse in the early cohort (P< .001), with adverse proximal and distal seal zone features (P< .001). Technical success was 16.2% higher in the late cohort, with significantly fewer type 1A/B endoleaks perioperatively (P< .001). In-hospital complications, driven by higher acute kidney injury and surgical site complications in the early cohort, resulted in a 16.5% difference between cohorts (P< .05). At 1year of follow-up, outcome differences persisted; late-era patients had fewer 1A endoleaks, fewer graft complications, and better reintervention-free survival. From a granular dataset of EVAR patients, we found an impact of EVAR repair era on early clinical outcomes; late cohort infrarenal EVAR patients had less severe preoperative anatomy and improved perioperative and follow-up outcomes to 1year, suggesting that the results of early EVAR randomized controlled trials may no longer be generalizable to modern practice.

Midterm outcomes of 455 patients receiving the AFX2 endovascular graft for the treatment of abdominal aortic aneurysm: A retrospective multi-center analysis.

Since being introduced into clinical practice the AFX family of endografts has undergone labelling updates, design and manufacturing changes to address a Type III failure mode. The published literature on the performance of the current endograft–AFX2 –is limited to small series with limited follow up. The present study reports the largest series of patients implanted with AFX2 for the treatment of abdominal aortic aneurysms. The study was a retrospective, 5 center study of patients receiving an AFX2 endograft from January 2016 until Dec 2020. Electronic case report forms were provided to four of the centers, with one additional site providing relevant outcomes in an independent dataset. Relevant outcomes were reported via Kaplan-Meier analysis and included all-cause mortality, aneurysm-related mortality, post EVAR aortic rupture, open conversion, device related reinterventions and endoleaks. Among a cohort of 460 patients, 405 underwent elective repair of an AAA, 50 were treated for a ruptured AAA, and 5 were aorto-iliac occlusive disease cases. For the elective cohort (mean age 73.7y, 77% male, mean AAA diameter 5.4cm), the peri-operative mortality was 1.7%. Freedom from aneurysm-related mortality was 98.2% at 1,2,3 and 4 years post-operatively, there were no post-operative aortic ruptures, and 2 patients required open conversion. Freedom from Type Ia endoleaks was 99.4% at 1, 2, 3 and 4 years. Freedom from Type IIIa and Type IIIb endoleaks were 100% and 100% (year 1), 100% and 99.6% (year 2), 99.4% and 99.6% (year 3), 99.4% and 99.6% (year 4) respectively. Freedom from all device-related reintervention (including Type II endoleaks) at 4 y was 86.8%. The AFX2 endograft appears to perform to a satisfactory standard in terms of patient centric outcomes in mid-term follow up. The Type Ia and Type III endoleaks rates at 4y appear to be within acceptable limits. Further follow up studies are warranted.

LncRNA GAS5 promotes abdominal aortic aneurysm formation through regulating the miR-185-5p/ADCY7 axis

One of the causes of abdominal aortic aneurysm (AAA) is the apoptosis of vascular smooth muscle cells. Many long noncoding RNA (lncRNAs) have been implicated in AAA formation. However, the mechanism of growth arrest-specific 5 (GAS5) in AAA formation is not yet clear. The expression levels of GAS5, microRNA-185-5p (miR-185-5p) and adenylate cyclase 7 (ADCY7) were determined by quantitative real-time PCR. Angiotensin II (ANGII) was used to induce AAA cell models. Cell viability was detected by MTT assay, and cell apoptosis was assessed by flow cytometry. Western blot analysis was used to test the protein expression levels. Besides, a dual-luciferase reporter assay was used to identify the mechanism of GAS5. GAS5 was upregulated in AAA tissues and ANGII-induced human aortic smooth muscle cells (HASMCs). GAS5 overexpression inhibited proliferation and promoted apoptosis and inflammatory response in ANGII-induced HASMCs, while its knockdown had the opposite effects. MiR-185-5p could be absorbed by GAS5, and its inhibitor could invert the effects of GAS5 silencing on proliferation, apoptosis and inflammatory response in ANGII-induced HASMCs. ADCY7 was a target of miR-185-5p. ADCY7 knockdown increased proliferation, while decreased apoptosis and inflammatory response in ANGII-induced HASMCs. Also, overexpressed ADCY7 reversed the effect of miR-185-5p overexpression on proliferation, apoptosis and inflammatory response in ANGII-induced HASMCs. GAS5 positively regulated the ADCY7 expression to inhibit the activity of the AKT signaling pathway by sponging miR-185-5p. LncRNA GAS5 contributed to AAA formation through regulating HASMCs proliferation, apoptosis and inflammatory response, which might provide new ideas for the treatment of AAA.

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

ABSTRACT Introduction The Incraft aortic stent graft (Cordis, Bridgewater, NJ, USA) is a trimodular endovascular stent graft with a conventional suprarenal active fixation specifically designed to overcome the anatomic limitation of small, stenotic, and tortuous iliac vessels. Areas covered The present article provides a complete description of the Incraft stent graft, its clinical performance, its technical characteristics as well as a comparison with other competitive endografts. Expert opinion The Incraft stent graft is an EVAR ultra low-profile device initially designed for overcoming the limitation of the hostile iliac anatomy. Recently, the device is being increasingly used in real-world conditions and not only in complex iliac anatomies with good mid-term results. Whether it remains a useful EVAR toolbox or will become a workhorse endograft is yet to be determined.

Failure to preserve the internal iliac artery during abdominal aortic aneurysm repair is associated with mortality and ischemic complications

ObjectiveOpen or endovascular repair of abdominal aortic aneurysms (AAAs) can involve sacrifice of the internal iliac artery (IIA). In the present study, we investigated the effect of IIA exclusion on ischemic complications and overall mortality. MethodsThe data from 326 patients who had undergone elective open surgical or endovascular treatment of a nonruptured AAA from January 2010 to December 2019 in a tertiary hospital were retrospectively reviewed. Ischemic complications included buttock claudication, spinal ischemia (including paraparesis), ischemic colitis, lower limb paresthesia, and skin necrosis. Their duration and mortality during the study period were investigated. ResultsNearly 50% of patients (148; 45.4%) had undergone endovascular aortic aneurysm repair and 178 (54.6%) had undergone open surgery. The median patient age was 78 years (range, 31-94 years). The median follow-up period was 1140 days (range, 0-4757 days). Of the 326 patients, 50 (15.3%) had died during follow-up. The bilateral IIAs were preserved in 187 patients (57.4%), a single IIA in 86 patients (26.4%), and no IIA in 53 patients (16.3%). Ischemic complications occurred in 57 patients (17.5%). Multivariable analysis revealed failure to preserve the bilateral IIAs (hazard ratio [HR], 8.65; 95% confidence interval [CI], 4.31-17.36; P < .01), management of the IIA (HR, 3.05, 95% CI, 2.17-4.28; P < .01), and hyperlipidemia (HR, 2.09; 95% CI, 1.04-4.17; P = .04) affected the occurrence of ischemic complications. Furthermore, univariable analysis revealed that patients had experienced more ischemic complications when a single IIA (HR, 6.97; 95% CI, 3.74-13.02; P < .01) or none of the IIAs had been preserved (HR, 8.88; 95% CI, 4.12-19.16; P < .01) than when both IIAs were preserved. Moreover, multivariable analysis revealed that stage 5 chronic kidney disease (HR, 2.7; 95% CI, 1.09-6.14; P = .03), age >75 years (HR, 2.48; 95% CI, 1.12-5.49; P = .03), cerebrovascular accident (HR, 1.95; 95% CI, 1.00-3.78; P = .05), and failure to preserve the bilateral IIAs (HR, 1.91; 95% CI, 1.02-3.46; P = .04) were associated with higher mortality after AAA repair. ConclusionsIIA exclusion is a risk factor for ischemic complications and overall mortality. Thus, preservation of the IIA as much as possible during AAA repair is recommended.

Automatic Measurement of Maximal Diameter of Abdominal Aortic Aneurysm on Computed Tomography Angiography Using Artificial Intelligence

IntroductionThe treatment of abdominal aortic aneurysm relies on surgical repair and the indication mainly depends on its size evaluated by the maximal diameter (Dmax). The aim of this study was to evaluate a new automatic method based on artificial intelligence to measure the Dmax on computed tomography angiography. MethodsA fully automatic segmentation of the vascular system was performed using a hybrid method combining expert system with supervised deep learning. The aorta centreline was extracted from the segmented aorta and the aortic diameters were automatically calculated. Results were compared to manual segmentation performed by two human operators. ResultsThe median absolute error between the two human operators was 1.2 mm (IQR 0.5–1.9). The automatic method using the deep learning algorithm demonstrated correlation with the human segmentation, with a median absolute error of 0.8 (0.5–4.2) mm and a coefficient correlation of 0.91 (P < 0.001). ConclusionsAlthough validation in larger cohorts is required, this method brings perspectives to develop new tools to standardize and automate the measurement of abdominal aortic aneurysm Dmax in order to help clinicians in the decision-making process.

Impact of calcification modeling to improve image fusion accuracy for endovascular aortic aneurysm repair.

Since the 1990s, endovascular aortic aneurysm repair (EVAR) has become a common alternative to open surgery for the treatment of abdominal aortic aneurysms (AAAs). To aid the deployment of stent-grafts, fluoroscopic image guidance can be enhanced using preoperative simulation and intraoperative image fusion techniques. However, the impact of calcification (Ca) presence on the guidance accuracy of such techniques is yet to be considered. In the present work, we introduce a guidance tool that accounts for patient-specific Ca presence. Numerical simulations of EVAR were developed for 12 elective AAA patients, both with (With-Ca) and without (No-Ca) Ca consideration. To assess the accuracy of the simulations, the image results were overlaid on corresponding intraoperative images and the overlay error was measured at selected anatomical landmarks. With this approach we gained insight into the impact of Ca presence on image fusion accuracy. Inclusion of Ca improved mean image fusion accuracy by 8.68 ± 4.59%. In addition, a positive correlation between the relative Ca presence and the image fusion accuracy was found (R=.753, p < .005). Our results suggest that considering Ca presence in patient-specific EVAR simulations increases the reliability of EVAR image guidance techniques that utilize numerical simulation, especially for patients with severe aortic Ca presence.

Abdominal aortic aneurysm neck dilatation and sac remodeling in fenestrated compared to standard endovascular aortic repair.

Contemporary commercially available endovascular devices for the treatment of abdominal aortic aneurysm (AAA) include standard endovascular aortic repair (sEVAR) or fenestrated EVAR (fEVAR) endografts. However, aortic neck dilatation (AND) can occur in nearly 25% of patients following EVAR, resulting in loss of proximal seal with risk of aortic rupture. AND has not been well characterized in fEVAR, and direct comparisons studying AND between fEVAR and sEVAR have not been performed. This study aims to analyze AND in the infrarenal and suprarenal aortic segments, including seal zone, and quantify sac regression following fEVAR implantation compared to sEVAR. A retrospective review of prospectively collected data on 20 consecutive fEVAR patients (Cook Zenith® Fenestrated) and 20 sEVAR (Cook Zenith®) patients was performed. Demographic data, anatomic characteristics, procedural details, and clinical outcome were analyzed. Pre-operative, post-operative (1month), and longest follow-up CT scan at an average of 29.3months for fEVAR and 29.8months for sEVAR were analyzed using a dedicated 3D workstation (iNtuition, TeraRecon Inc, Foster City, California). Abdominal aortic aneurysm neck diameter was measured in 5mm increments, ranging from 20mm above to 20mm below the lowest renal artery. Sub-analysis comparing the fEVAR to the sEVAR group at 12months and at greater than 30months was performed. Standard statistical analysis was done. Demographic characteristics did not differ significantly between the two cohorts. The fEVAR group had a larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length. On follow-up imaging, the suprarenal aortic segment dilated significantly more at all locations in the fEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared to the sEVAR group. Compared to the sEVAR cohort, the fEVAR patients demonstrated significantly greater positive sac remodeling as evident by more sac diameter regression, and elongation of distance measured from the celiac axis to the most cephalad margin of the sac. Device migration, endoleak occurrence, re-intervention rate, and mortalities were similar in both groups. Compared to sEVAR, patients undergoing fEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in fEVAR patients, appears more stable in the post-operative period as compared to sEVAR. Moreover, the fEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in fEVAR may result in a previously undescribed increased level of protection against infrarenal neck dilatation. We hypothesize that the resultant decreased endotension conferred by better seal zone may be responsible for a more dramatic sac shrinkage in fEVAR.

Profile of the Ovation ALTO abdominal stent graft for the treatment of abdominal aortic aneurysms: overview of its safety and efficacy

ABSTRACT Introduction The Ovation ALTO is the next generation aortic stent graft from Endologix for the treatment of infra-renal abdominal aortic aneurysms. The device uses polymer-injected rings to create a proximal seal at the aneurysm neck. Areas Covered Results from the first clinical study of the ALTO graft are analyzed and the potential benefits of the graft in minimizing post-treatment aneurysmal neck dilation discussed. The implications of the ALTO’s Instructions-For-Use (IFU) and low-profile delivery system are also reviewed. Expert Opinion The re-positioning of the sealing rings higher on the graft and an integrated compliant balloon are the most significant improvements on the Ovation iX, facilitating accurate placement of the proximal sealing ring and prompt balloon dilation of the polymer rings. The expansion the IFU to include neck lengths of ≥7 mm will mean more patients are eligible for infra-renal EVAR within IFU with the ALTO device. The published data on the device to date is limited. With over 1000 implants worldwide we would hope for more published data to become available. If this demonstrates similar mid-term results to that seen with the Ovation iX in arguably more hostile neck anatomy, then the Ovation ALTO is likely to be more widely used.

Potential Benefits of Phytochemicals for Abdominal Aortic Aneurysm.

Abdominal aortic aneurysms (AAAs) are a leading cause of death in older adults due to aortic rupture. There are currently no effective medical therapies for AAA, with surgery being the only acceptable treatment. There is frequently an extended period between AAA diagnosis and treatment by corrective surgery, during which an effective drug therapy could prevent or delay the need for AAA repair. This review aimed to critically summarize prior research investigating the potential benefits of phytochemicals in preventing or treating AAA. In vitro, in vivo, and human studies examining the effect of phytochemicals in AAA models and patients were critically summarised. Some preliminary data support the further investigation of curcumin, radix astragali, grape seed polyphenols, resveratrol, Ginkgo biloba extract (EGb 761), Ginsenoide Rb1, Dan Hong, Epigallocatechin-3-gallate, Baicalein, Fucoidan, Quercetin, and Salvianolic acid as potential treatments for AAA. Experimental in vivo and in vitro studies suggest the potential benefits of a number of medicinal herbs and phytochemicals in preventing or reducing the progression of AAA. In order to assess whether these findings can be translated into proven treatments, adequately designed double-blind randomized clinical trials will be required.

Cryopreserved venous allograft in the treatment of a mycotic abdominal aortic aneurysm caused by group B Streptococcus

We report a case of a mycotic abdominal aortic aneurysm caused by invasive group B streptococcus. Given the anatomical suitability with healthy segments of aortoiliac vessels, in situ repair was performed. A cryopreserved femoral vein graft was chosen because of risks of graft reinfection and negated the need for bilateral femoral vein harvest. The patient remained clinically well and the graft patent with no concerns at 6 months of follow-up. A review of literature on group B Streptococcus aortitis was performed.