One-year follow-up after active aortic aneurysm sac treatment with shape memory polymer devices during endovascular aneurysm repair

OBJECTIVE

To determine the safety and efficacy of treating abdominal aortic aneurysm (AAA) sacs with polyurethane shape memory polymer (SMP) devices during endovascular aneurysm repair (EVAR), using a technique to fully treat the target lumen after endograft placement (aortic flow volume minus the endograft volume). SMP devices self-expand in the sac to form a porous scaffold that supports thrombosis throughout its structure.

METHODS

Two identical prospective, multicenter, single-arm studies were conducted in New Zealand and the Netherlands. The study population was adult candidates for elective EVAR of an infrarenal AAA (diameter of ≥55 mm in men and ≥50 mm in women). Key exclusion criteria were an inability to adequately seal a common iliac artery aneurysm, patent sac feeding vessels of >4 mm, and a target lumen volume of <20 mL or >135 mL. Target lumen volumes were estimated by subtracting endograft volumes from preprocedural imaging-based flow lumen volumes. SMP devices were delivered immediately after endograft deployment via a 6F sheath jailed in a bowed position in the sac. The primary efficacy end point was technical success, defined as filling the actual target lumen volume with fully expanded SMP at the completion of the procedure. Secondary efficacy outcome measures during follow-up were the change in sac volume and diameter, rate of type II endoleak and type I or III endoleaks, and the rate of open repair and related reinterventions, with data collection at 30 days, 6 months, and 1 year (to date). Baseline sac volumes and diameters for change in sac size analyses were determined from 30-day imaging studies. Baseline and follow-up volumes were normalized by subtraction of the endograft volume.

RESULTS

Of 34 patients treated with SMP devices and followed per protocol, 33 patients were evaluable at 1 year. Preprocedural aneurysm volume was 181.4 mL (95% confidence interval [CI], 150.7-212.1 mL) and preprocedural aneurysm diameter was 60.8 mm (95% CI, 57.8-63.9 mm). The target lumen volume was 56.3 mL (95% CI, 46.9-65.8 mL). Technical success was 100% and the ratio of SMP fully expanded volume to estimated target lumen volume was 1.4 ± 0.3. Baseline normalized sac volume and diameter were 140.7 mL (95% CI, 126.6-154.9 mL) and 61.0 mm (95% CI, 59.7-62.3 mm). The adjusted mean percentage change in normalized volume at 1 year was -28.8% (95% CI, -35.3 to -22.3%; P < .001). The adjusted mean change in sac diameter at 1 year was -5.9 mm (95% CI, -7.5 to -4.4 mm; P < .001). At 1 year, 81.8% of patients (95% CI, 64.5%-93.0%) achieved a ≥10% decrease in normalized volume and 57.6% of patients (95% CI, 39.2%-74.5%) achieved a ≥5 mm decrease in diameter. No device- or study procedure-related major adverse events occurred through 1 year after the procedure.

CONCLUSIONS

Treatment of AAA sacs with SMP devices during EVAR resulted in significant sac volume and diameter regression at 1 year with an acceptable safety profile in this prospective study.

Two-Stage Endovascular Aneurysm Repair with Preemptive Embolization: A Retrospective Study

BACKGROUND

Type II endoleak is the most common complication of endovascular aneurysm repair. Retrograde perfusion from the aneurysmal sac side branch to the aneurysmal sac, including the inferior mesenteric artery and lumbar arteries, is associated with adverse events after endovascular aneurysm repair, such as aneurysm sac enlargement, reintervention, rupture, and abdominal aortic aneurysm-related death. Preemptive embolization of the aneurysmal sac side branch before endovascular aneurysm repair is an effective and safe procedure for preventing type II endoleak and reducing the size of the aneurysmal sac. Since 2019, we have been conducting preemptive embolization of the inferior mesenteric artery and lumbar arteries. Thus, we intended to work on a two-stage endovascular aneurysm repair in which embolization and endovascular aneurysm repair are performed on separate days, owing to concerns about prolonged operative time and increased contrast media use and radiation exposure from performing endovascular aneurysm repair simultaneously. This study aimed to evaluate the effects of a two-stage endovascular aneurysm repair.

METHODS

This retrospective study included 114 cases of endovascular aneurysm repair (95 men and 19 women) for AAA performed at our hospital between January 2019 and December 2022. Inferior mesenteric artery and lumbar artery embolization were performed simultaneously with endovascular aneurysm repair (simultaneous group) in 49 cases, and two-stage embolization was performed (two-stage group) in 30 cases. The primary endpoints included the occurrence of T2EL during follow-up and the embolization rate of the IMA or LAs.

RESULTS

Type II endoleak did not occur in the two-stage group (follow-up period: 35 ± 6.2 months), whereas it was observed in 8.2% of patients more than 6 months after EVAR in the simultaneous group (follow-up period: 28 ± 5.5 months). While the total operative time was 340 ± 111.2 min in the simultaneous group, the durations for embolization and endovascular aneurysm repair in the two-stage group were 169 ± 35.5 min and 135.0 ± 26.4 min (total time 304 ± 31.2 min, P = 0.21), respectively, indicating a reduction in the total time required for the 2 techniques. The total amounts of contrast media used in the simultaneous and two-stage groups were 200.0 ± 179.2 mL and 182.0 ± 51.2 mL (P = 0.42), respectively, and the corresponding total radiation doses were 2502.4 ± 690.5 mGy and 2114.6 ± 351.2 mGy (P = 0.28), respectively, showing a decrease in both in the two-stage group. The lumbar artery embolization rates were 74.3% and 87.9% (P < 0.01) in the simultaneous and two-stage groups, respectively, indicating a significant difference.

CONCLUSIONS

Two-stage endovascular aneurysm repair with preemptive embolization of the inferior mesenteric artery and lumbar arteries may be an effective strategy for reducing type II endoleak occurrence, overall operative time, contrast use, and overall radiation exposure.

Local Anesthesia for Endovascular Repair of Abdominal Aortic Aneurysm Allows for Accurate Graft Deployment with Durable Results

BACKGROUND

Local anesthesia (LA) is sparsely used in endovascular aneurysm repair (EVAR) despite short-term benefit, likely secondary to concerns over patient movement preventing accurate endograft deployment. The objective of this study is to examine the association between anesthesia type and endoleak, sac regression, reintervention, and mortality.

METHODS

The Vascular Quality Initiative database was queried for all EVAR cases from 2014 to 2022. Patients were included if they underwent percutaneous elective EVAR with anatomical criteria within instructions for use of commercially approved endografts. Multivariable logistic regression with propensity score weighting was used to determine the association between anesthesia type on the risk of any endoleak noted by intraoperative completion angiogram and sac regression. Multivariable survival analysis with propensity score weighting was used to determine the association between anesthesia type and endoleak at 1 year, long-term reintervention, and mortality.

RESULTS

Thirteen thousand nine hundred thirty two EVARs met inclusion criteria: 1,075 (8%) LA and 12,857 (92%) general anesthesia (GA). On completion angiogram, LA was associated with fewer rates of any endoleaks overall (16% vs. 24%, P < 0.001). On multivariable analysis with propensity score weighting, LA was associated with similar adjusted odds of any endoleak on intraoperative completion angiogram (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.47-0.68) as well as combined type 1a and type 1b endoleaks (OR 0.72, 95% CI 0.47-1.09). Follow-up computed tomography imaging at 1 year was available for 4,892 patients, 377 (8%) LA and 4,515 (92%) GA. At 1 year, LA was associated with similar rate of freedom from any endoleaks compared to GA (0.66 [95% CI 0.63-0.69] vs. 0.71 [95% CI 0.70-0.72], P = 0.663) and increased rates of sac regression (50% vs. 45%, P = 0.040). On multivariable analysis with propensity score weighting, LA and GA were associated with similar adjusted odds of sac regression (OR 1.22, 95% CI 0.97-1.55). LA and GA had similar rates of endoleak at 1 year (hazard ratio [HR] 0.14, 95% CI 0.63-1.07); however, LA was associated with decreased hazards of combined type 1a and 1b endoleaks at 1 year (HR 0.87, 95% CI 0.80-0.96). LA and GA had similar adjusted long-term reintervention rate (HR 0.77, 95% CI 0.44-1.38) and long-term mortality (HR 1.100, 95% CI 079-1.25).

CONCLUSIONS

LA is not associated with increased adjusted rates of any endoleak on completion angiogram or at 1-year follow-up compared to GA. LA is associated with decreased adjusted rates of type 1a and type 1b endoleak at 1 year, but similar rates of sac regression, long-term reintervention, and mortality. Concerns for accurate graft deployment should not preclude use of LA and LA should be increasingly considered when deciding on anesthetic type for standard elective EVAR.

Comparison of bare and nonbare stent grafts during thoracic endovascular aneurysm repair of the aortic arch

OBJECTIVE

We compared the outcomes of patients treated with nonbare stents (NBS) and proximal bare stents (PBS) endografts with a proximal landing zone in the aortic arch during thoracic endovascular aortic repair (TEVAR).

METHODS

We conducted a retrospective cohort, observational, multicenter study that included 361 consecutive TEVAR procedures undertaken between November 2005 and December 2021. TEVAR patients with both BS and NBS Relay stent graft configurations with proximal landing in zones 1, 2, or 3 were enrolled. Preoperative anamnestic and morphological data, clinical outcomes, and aortic modifications 30 days after surgery and at the latest follow-up available were collected. The primary outcome was freedom from proximal endoleak (type IA) comparing the two configurations. Total and detailed endoleak rates, clinical and technical success, intraoperative additional maneuvers, major adverse events, and reinterventions were secondary outcomes.

RESULTS

The median follow-up was 4.9 (interquartile range, 2.0-8.1) years. No statistically significant difference between NBS and PBS patients concerning 30-day major adverse events, retrograde aortic dissection, disabling stroke, or late type IA endoleak (10.8% vs 7.8%; P = .597). Aneurysmal disease (P = .026), PLZ diameter of >34 mm (P = .026), aortic tortuosity index of >1.4 (P = .008), type III aortic arch (P = .068), and PLZ thrombus (P = .014) identified as risk factors by univariate Cox regression analysis. PLZ thrombus was the only type IA endoleak risk factor at multivariate Cox regression (P = .016).

CONCLUSIONS

We found no statistically significant difference in freedom from type IA endoleak, retrograde dissection, or disabling stroke observed between the NBS and the BS configuration of the Relay endograft. Proximal landing zone thrombotic apposition was a prominent risk factor for type IA endoleak after TEVAR.

Contrast-Enhanced Ultrasound after Endovascular Aortic Repair: Supplement and Potential Substitute for CT in Early- and Long-Term Follow-Up

BACKGROUND

Endoleaks are the most common complication after endovascular aneurysm repair (EVAR). Computed tomography angiography (CTA) is presently the golden standard for lifelong surveillance after EVAR. Several studies and meta-analyses have shown contrast-enhanced ultrasound (CEUS) to be a good alternative. The main goal of our study was to further validate the inclusion of CEUS in follow-up examination protocols for the systematic surveillance after EVAR.

METHODS

A retrospective analysis of patients who had received CEUS as part of their routine surveillance after EVAR at our center was conducted. Detection rate and classification of endoleak types were compared between available postinterventional CTA/magnetic resonance angiography and follow-up CEUS examinations. Last preinterventional CTAs before EVAR served as baselines with focus on potential cofactors such as age, body mass index, maximum aortic aneurysm diameters, endoleak orientation, and distance-to-surface influencing detection rates and classification.

RESULTS

In total, 101 patients were included in the analysis. Forty-four endoleaks (43.5% of cases) were detected by either initial CEUS or CTA, mostly type II (37.6% of the included patients). Initial CEUS showed an endoleak sensitivity of 91.2%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 84.6%. No covariate with an influence on the correct classification could be identified either for CEUS or CT.

CONCLUSIONS

CEUS should be considered a valid complementary method to CTA in the lifelong surveillance after EVAR. As type II endoleaks seem to be a common early-term, sometimes spontaneously resolving complication that can potentially be missed by CTA, we suggest combined follow-up protocols including CEUS in the early on postinterventional assessment.

Multi-Energy Low-Kiloelectron Volt versus Single-Energy Low-Kilovolt Images for Endoleak Detection at CT Angiography of the Aorta

Purpose To compare image quality, diagnostic performance, and conspicuity between single-energy and multi-energy images for endoleak detection at CT angiography (CTA) after endovascular aortic repair (EVAR). Materials and Methods In this single-center prospective randomized controlled trial, individuals undergoing CTA after EVAR between August 2020 and May 2022 were allocated to imaging using either low-kilovolt single-energy images (SEI; 80 kV, group A) or low-kiloelectron volt virtual monoenergetic images (VMI) at 40 and 50 keV from multi-energy CT (80/Sn150 kV, group B). Scan protocols were dose matched (volume CT dose index: mean, 4.5 mGy ± 1.8 [SD] vs 4.7 mGy ± 1.3, P = .41). Contrast-to-noise ratio (CNR) was measured. Two expert radiologists established the reference standard for the presence of endoleaks. Detection and conspicuity of endoleaks and subjective image quality were assessed by two different blinded radiologists. Interreader agreement was calculated. Nonparametric statistical tests were used. Results A total of 125 participants (mean age, 76 years ± 8; 103 men) were allocated to groups A (n = 64) and B (n = 61). CNR was significantly lower for 40-keV VMI (mean, 19.1; P = .048) and 50-keV VMI (mean, 16.8; P < .001) as compared with SEI (mean, 22.2). In total, 45 endoleaks were present (A: 23 vs B: 22). Sensitivity for endoleak detection was higher for SEI (82.6%, 19 of 23; P = .88) and 50-keV VMI (81.8%, 18 of 22; P = .90) as compared with 40-keV VMI (77.3%, 17 of 22). Specificity was comparable among groups (SEI: 92.7%, 38 of 41; both VMI energies: 92.3%, 35 of 38; P = .99), with an interreader agreement of 1. Conspicuity of endoleaks was comparable between SEI (median, 2.99) and VMI (both energies: median, 2.87; P = .04). Overall subjective image quality was rated significantly higher for SEI (median, 4 [IQR, 4-4) as compared with 40 and 50 keV (both energies: median, 4 [IQR, 3-4]; P < .001). Conclusion SEI demonstrated higher image quality and comparable diagnostic accuracy as compared with 50-keV VMI for endoleak detection at CTA after EVAR. Keywords: Aneurysms, CT, CT Angiography, Vascular, Aorta, Technology Assessment, Multidetector CT, Abdominal Aortic Aneurysms, Endoleaks, Perigraft Leak Supplemental material is available for this article. © RSNA, 2024.

Systematic review and meta-analysis of outcomes after semi-conversion with graft preservation for failed endovascular aneurysm repair

OBJECTIVE

The aim of this study was to evaluate the outcomes after semi-conversion (open conversion with graft preservation) after failed endovascular aneurysm repair (EVAR). The primary outcomes were 30-day mortality and semi-conversion failure. Secondary outcomes were 30-day major systemic complications, endoleak recurrence, reinterventions, and overall survival.

METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol was prospectively registered on PROSPERO (CRD42023421153). All studies reporting the outcomes of semi-conversions for failed EVAR were eligible for inclusion. Quality assessment was performed using the Methodological Index for Non-Randomized Studies (MINORS) tool. A random effects meta-regression of proportions was conducted using the double arcsine-Tukey transformation, given the frequent zero event rate in the primary outcome. Heterogeneity was assessed with the I2 statistic.

RESULTS

Eight studies were included in the review after full text screening. A total of 196 patients underwent semi-conversion at a mean time from EVAR of 47.4 months, 68.9% in an elective setting. Mean age at conversion was 78.1 years, and the main indication was isolated endoleak type II (70.1% of cases). Aortic clamping was not necessary in 92.3% of semi-conversions; the aortic sac was opened in 96.1% of cases; in 93.3% of cases, ligation/suture of one or more culprit arteries were performed; and aortic neck banding was executed in 29.2%. At 30 days from surgery, the pooled mortality and the major systemic complications rates were 5.3% (I2 = 24.9%) and 13.4% (I2 = 54.3%), respectively. At follow-up, endoleak recurred after 12.6% semi-conversions (I2 = 83.2%), and the rate of reinterventions was 7% (I2 = 50.1%); the semi-conversion failure rate was 5.5% (I2 = 54.1%), and the overall survival was 84.6% (I2 = 33.3%).

CONCLUSIONS

Semi-conversions have acceptable 30-day mortality rates, but the early and mid-term risks of complications, reinterventions, ruptures, and infections are not negligible. This procedure might be an alternative to complete or partial graft explant in patients whom aortic cross-clamping is not ideal.

Is There a Role for Heli-FX Endoanchors in Treating Type 1B Common Iliac Artery Endoleaks?

OBJECTIVES

The management of type 1B endoleaks following endovascular aortic aneurysm repair (EVAR) can be challenging. The Heli-FX Endoanchor system effectively treats proximal type 1A endoleaks but has not been used for type 1B common iliac artery endoleaks. This study demonstrates that it is both safe and effective in being used in the common iliac artery (CIA) limb of an EVAR.

METHODS

A retrospective review of patients identified through coding and medical records was performed to extract information on demographics, aneurysmal features, operative features, and postoperative outcomes. This was then collated and analysed thoroughly and compared to existing research.

RESULTS

Four patients with six type 1B CIA endoleaks were treated with Heli-FX Endoanchors in the CIA limbs of EVAR grafts. There was 100% technical success rate with complete exclusion of the endoleaks at 6 months. With mean follow up of 714 days, there were no Endoanchor-specific complications. One patient required explantation of the aortic endograft due to contralateral limb fracture, where it was found that an Endoanchor had penetrated the common iliac vein, requiring primary closure.

CONCLUSIONS

Heli-FX Endoanchors were effective within this cohort of patients, though key risks were identified. Adjacent anatomy to the CIA must be considered, which also have nearly half the arterial thickness compared to the aorta. Pre-operative planning is essential given the theoretical risk of placing Endoanchors.

Effectiveness of Intra-operative Contrast-Enhanced Ultrasound Assessment to Optimize Type II Endoleak Embolization

PURPOSE

To analyze the effectiveness of type II endoleaks (T2E) embolization using intra-operative contrast-enhanced ultrasound (CEUS).

METHODS

Consecutive patients treated for T2E underwent a standardized protocol with trans-arterial or trans-lumbar access, large volume embolization, onlay fusion, and intra-operative CEUS. Technical success was defined by exclusion of endoleak by CEUS.

RESULTS

Twenty-six patients (mean age 81 ± 11 years old; 89% male) were treated. The mean aneurysm sac enlargement was 11 ± 8 mm from T2E diagnosis. Embolization was performed using Onyx® 18 in all patients with adjunctive coils in 13 patients (50%). After the first embolization, CEUS documented residual T2E in 13 patients (50%). Ten patients (38%) had additional embolization, which successfully eradicated the T2E in seven of them. Technical success was 50% after the first embolization attempt and 77% after additional attempts guided by CEUS (P = 0.080). There was no mortality. Median imaging follow-up was 22 months. Among the 20 patients with no residual T2E on completion CEUS, 16 (80%) had sac stabilization and none required additional interventions for T2E. Of the six patients with residual T2Es on CEUS, three had sac stabilization (50%) and one required additional reintervention for T2E. There was one late aortic rupture at 56 months.

CONCLUSION

One in two patients treated by T2E embolization had residual endoleak on intra-operative CEUS after a first embolization attempt, decreasing to one in four patients after multiple attempts. A negative completion CEUS following embolization was associated with higher rates of sac stabilization and no need for additional T2E embolization.

Reducing aneurysm sac growth and secondary interventions following endovascular abdominal aortic aneurysm repair by preemptive coil embolization of the inferior mesenteric artery and lumbar arteries

OBJECTIVE

Type II endoleak (EL-2) is the most common complication following endovascular aneurysm repair (EVAR), leading to continued sac growth and potential rupture. In this study, we examined the association between patency of the inferior mesenteric artery (IMA) and lumbar arteries (LAs) with respect to sac growth. The effect of preemptive embolization of the IMA and/or LAs on the need for secondary interventions for sac growth post-EVAR was also evaluated.

METHODS

A retrospective cohort study was performed on consecutive patients who underwent EVAR for non-ruptured, infrarenal abdominal aortic aneurysms (AAAs) from January 2012 to December 2020. A select group of patients underwent preemptive embolization of the IMA and/or LA. Patients with any types I, III, or IV endoleaks were excluded. Patency of the IMA and LA on preoperative computed tomography angiogram (CTA) was evaluated on TeraRecon workstation. All secondary interventions to treat EL-2 were recorded. Sac growth was defined as centerline axial diameter increase of ≥5 mm on follow-up CTA.

RESULTS

A total of 300 patients (mean age, 74 ± 8.5 years; 83.7% male) underwent EVAR. Ninety-nine patients had preemptive embolization of the IMA and/or LA. Mean follow-up of the cohort was 59.3 ± 30.5 months. Thirty-six patients (12%) demonstrated sac growth on follow-up; 12 of these (33.3%) had preemptive embolization. The median time until detection of sac growth was 28.8 months (interquartile range, 15.2-46.5 months), with a mean growth of 10.1 ± 6.4 mm. Sac growth was significantly associated with presence of EL-2: 27 of 36 (75%) with EL-2 vs 9 of 36 (25%) without EL-2 (P < .001). Patients with sac growth had a higher mean total number (2.6 ± 1.5) of patent lower LAs (L3, L4) compared with those without (2.0 ± 1.4; P = .03). Patency of L1, L2, and L3 LAs were not associated with sac growth. However, patency of at least one L4 LA was significantly associated with sac growth (14.8% vs 7.7%; P = .04). The highest incidence of sac growth (17.6%) was seen when both IMA and L4 LA were patent; significantly different from the lowest incidence (5.3%) when both were occluded preoperatively (P = .018). Preemptive coiling of the IMA and/or LA significantly reduced the need for post-EVAR secondary intervention for sac growth. Freedom from post-EVAR secondary intervention was achieved in 92 of 99 (92.9%) pre-EVAR coiled patients vs 163 of 201 (81.5%) patients who did not undergo pre-EVAR coiling (P = .009).

CONCLUSIONS

Preemptive coil embolization of the IMA and LAs, especially L4 LA, reduces the need for secondary interventions for sac growth, potentially improving the long-term durability of EVAR.

Impact of the Lumbar Arteries on Aneurysm Diameter and Type 2 Endoleak after Endovascular Aneurysm Repair

BACKGROUND

Prophylactic embolization of the inferior mesenteric artery (IMA) during endovascular aneurysm repair (EVAR) is recommended to prevent type 2 endoleak (T2EL). However, the impact of patent lumbar arteries (LAs) on T2ELs and aneurysm diameter has not been elucidated.

METHODS

Fifty-seven consecutive patients who underwent EVAR at our institution between January 2013 and September 2022 and whose IMA had been occluded preoperatively or newly occluded postoperatively were included in the study. Predictive factors for aneurysm sac enlargement, sac shrinkage, and T2EL were investigated.

RESULTS

T2ELs occurred in 22.8% of the patients. The 4-year cumulative incidence rates of sac enlargement and shrinkage were 6.7% and 64.6%, respectively. The number of postoperative patent LAs was identified as a risk factor for T2ELs (95% confidence interval [CI]: 1.54-12.7, P = 0.0065). The number of postoperative patent LAs was found to be a significant predictor of sac enlargement (adjusted hazard ratio [AHR] 3.15, 95% CI: 1.43-6.96, P = 0.0045) and shrinkage (AHR 0.63, 95% CI: 0.43-0.91, P = 0.014).

CONCLUSIONS

The current study demonstrated that the number of postoperative patent LAs had a significant impact on the development of T2ELs and the change in aneurysm diameter in patients in whom the IMA was occluded after EVAR.

Unenhanced computed tomography radiomics help detect endoleaks after endovascular repair of abdominal aortic aneurysm

OBJECTIVES

To explore the feasibility of unenhanced CT images for endoleak detection of abdominal aortic aneurysm (AAA) after endovascular repair (EVAR).

METHODS

Patients who visited our hospital after EVAR from July 2014 to September 2021 were retrospectively collected. Two radiologists evaluated the presence or absence of endoleaks using the combination of contrast-enhanced and unenhanced CT as the referenced standard. After segmenting the aneurysm sac of the unenhanced CT, the radiomic features were automatically extracted from the region of interest. Histogram features of patients with and without endoleak were statistically analyzed to explore the differences between the two groups. Twelve common machine learning (ML) models based on radiomic features were constructed to evaluate the performance of endoleak detection with unenhanced CT images.

RESULTS

The study included 216 patients (69 ± 8 years; 191 men) with AAA, including 64 patients with endoleaks. A total of 1955 radiomic features of unenhanced CT were extracted. Compared with patients without endoleak, the aneurysm sac outside the stent of patients with endoleak had higher CT attenuation (41.7 vs. 33.6, p < 0.001) with smaller dispersion (51.5 vs. 58.8, p < 0.001). The average area under the curve (AUC) of the ML models constructed with unenhanced CT radiomics was 0.86 ± 0.05, the accuracy was 81% ± 4, the sensitivity was 88% ± 10, and the specificity was 78% ± 5. When fixing the sensitivity to > 90% (92% ± 2), the models retained specificity at 72% ± 10.

CONCLUSIONS

Unenhanced CT features exhibit significant differences between patients with and without endoleak and can help detect endoleaks in AAA after EVAR with high sensitivity.

CLINICAL RELEVANCE STATEMENT

Unenhanced CT radiomics can help provide an alternative method of endoleak detection in patients who have adverse reactions to contrast media. This study further exploits the value of unenhanced CT examinations in the clinical management and surveillance of postoperative abdominal aortic aneurysm.

KEY POINTS

• Unenhanced CT features of the aneurysm sac outside the stent exhibit significant differences between patients with and without endoleak. The endoleak group showed higher unenhanced CT attenuation (41.7 vs 33.6, p < .001) with smaller dispersion (51.5 vs 58.8, p < .001) than the nonendoleak group. • Unenhanced CT radiomics can help detect endoleaks after intervention. The average area under the curve (AUC) of twelve common machine learning models constructed with unenhanced CT radiomics was 0.86 ± 0.05, the average accuracy was 81% ± 4. • When fixing the sensitivity to > 90% (92% ± 2), the machine learning models retained average specificity at 72% ± 10.

Enhanced visualization in endoleak detection through iterative and AI-noise optimized spectral reconstructions

To assess the image quality parameters of dual-energy computed tomography angiography (DECTA) 40-, and 60 keV virtual monoenergetic images (VMIs) combined with deep learning-based image reconstruction model (DLM) and iterative reconstructions (IR). CT scans of 28 post EVAR patients were enrolled. The 60 s delayed phase of DECTA was evaluated. Objective [noise, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR)] and subjective (overall image quality and endoleak conspicuity - 3 blinded readers assessment) image quality analyses were performed. The following reconstructions were evaluated: VMI 40, 60 keV VMI; IR VMI 40, 60 keV; DLM VMI 40, 60 keV. The noise level of the DLM VMI images was approximately 50% lower than that of VMI reconstruction. The highest CNR and SNR values were measured in VMI DLM images. The mean CNR in endoleak in 40 keV was accounted for as 1.83 ± 1.2; 2.07 ± 2.02; 3.6 ± 3.26 in VMI, VMI IR, and VMI DLM, respectively. The DLM algorithm significantly reduced noise and increased lesion conspicuity, resulting in higher objective and subjective image quality compared to other reconstruction techniques. The application of DLM algorithms to low-energy VMIs significantly enhances the diagnostic value of DECTA in evaluating endoleaks. DLM reconstructions surpass traditional VMIs and IR in terms of image quality.

Fate of primary determinate and indeterminate target vessel endoleaks after fenestrated-branched endovascular aortic repair

OBJECTIVE

The aim of this study was to investigate the outcomes of primary determinate and indeterminate target vessel endoleaks (TVELs) after fenestrated-branched endovascular aortic repair (F-BEVAR).

METHODS

We conducted a single-center retrospective study (2014-2023) on F-BEVAR for thoracoabdominal (TAAAs) or pararenal aortic aneurysms (PRAAs). TVELs were classified as "primary" if present at the first postoperative computed tomography angiogram. Endoleaks were defined "determinate" (dELs) if the cause (type Ic or IIIc) and implicated target vessel were identifiable and "indeterminate" (iELs) if contrast enhancement was detectable at the level of fenestrations/branches without any evident source. Endoleaks involving multiple inflows (type II and target vessels) were defined as "complex" (cELs). Endpoints were endoleak spontaneous resolution, 1-year aneurysm sac failure to regress (>5 mm diameter decrease), and 4-year endoleak-related secondary interventions. Kaplan-Meier estimates and Cox regression were used for the analysis.

RESULTS

There were 142 patients with JRAAs/PRAAs (n = 85; 60%) or TAAAs (n = 57; 40%), with 513 target arteries incorporated through a fenestration (n = 294; 57%) or directional branch (n = 219; 43%). Fifty-nine primary TVELs (12%) were identified in 35 patients (25%), a dEL in 20 patients (14%) and iEL in 15 (11%); 22 (15%) had a determinate or indeterminate cEL. Overall spontaneous resolution rate was 75% (95% confidence interval [CI], 51%-87%) at 4 years. cELs (odds ratio [OR], 5.00; 95% CI, 1.10-49.4; P < .001) and iELs after BEVAR (OR, 9.43; 95% CI, 3.41-56.4; P = .002) were more likely to persist >6 months, and persistent forms were associated with sac failure to regress at 1 year (OR, 1.72; 95% CI, 1.03-12.59; P = .040). Overall freedom from endoleak-related reinterventions was 85% (95% CI, 79%-92%) at 4 years, 92% (95% CI, 87%-97%) for those without primary TVELs and 62% (95% CI, 46%-84%) for those with any primary TVEL (P < .001). In particular, cELs (hazard ratio, 1.94; 95% CI, 1.4-18.81; P = .020) were associated with an increased need for reintervention. In case a secondary intervention was needed, iEL or cEL had an increased risk for multiple secondary procedures (hazard ratio, 2.67; 95% CI, 1.22-10.34; P = .034).

CONCLUSIONS

Primary TVELs are frequent after F-BEVAR, and a clear characterization of the endoleak source by computed tomography angiogram is not possible in 40% of patients. Most primary TVELs spontaneously resolve, but during follow-up, patients with any primary TVEL experience a worsened freedom from endoleak-related reinterventions that is mostly driven by persistence of cELs and post-BEVAR iELs. Multiple secondary procedures may be required in case of iELs or cELs.

CIRSE Standards of Practice on Management of Endoleaks Following Endovascular Aneurysm Repair

BACKGROUND

Endoleaks represent the most common complication after EVAR. Some types are associated with ongoing risk of aneurysm rupture and necessitate long-term surveillance and secondary interventions.

PURPOSE

This document, as with all CIRSE Standards of Practice documents, will recommend a reasonable approach to best practices of managing endoleaks. This will include imaging diagnosis, surveillance, indications for intervention, endovascular treatments and their outcomes. Our purpose is to provide recommendations based on up-to-date evidence, updating the guidelines previously published on this topic in 2013.

METHODS

The writing group was established by the CIRSE Standards of Practice Committee and consisted of clinicians with internationally recognised expertise in endoleak management. The writing group reviewed the existing literature performing a pragmatic evidence search using PubMed to select publications in English and relating to human subjects up to 2023. The final recommendations were formulated through consensus.

RESULTS

Endoleaks may compromise durability of the aortic repair, and long-term imaging surveillance is necessary for early detection and correct classification to guide potential re-intervention. The majority of endoleaks that require treatment can be managed using endovascular techniques. This Standards of Practice document provides up-to-date recommendations for the safe management of endoleaks.

Total Arch Thoracic Endovascular Aortic Repair Using Double Fenestrated Physician-Modified Stent-Grafts: 100 Patients

OBJECTIVE

The aim was to evaluate early and medium-term outcomes of double fenestrated physician-modified endovascular grafts for total endovascular aortic arch repair.

METHODS

This single-center retrospective analysis of prospectively-collected data included 100 patients, from January 2017 to December 2021, undergoing thoracic endovascular aortic repair (TEVAR) for zone 0. The fenestrations were a proximal larger fenestration that incorporated the brach2iocephalic trunk and left common carotid artery and a distal smaller fenestration for the left subclavian artery (LSA). Only the LSA fenestration was stented.

RESULTS

The median duration for stent-graft modification was 23±6 minutes. Of the 100 patients, 70 were men. The mean patient age was 70±10.5 years. Indications for treatment included degenerative aortic arch aneurysm (n=32), dissecting aortic arch aneurysm after type A dissections (n=23) and (n=19) after type B dissections, acute complicated type B dissection (n=16), and other pathologies (n=10). Technical success rate was 97%. The 30 day mortality was 2% (n=2). Four patients (4%) had minor stroke with full recovery. One patient (1%) had a type IA endoleak, 1 patient (1%) had a type IB endoleak, and 2 patients (2%) have a type II endoleak from the LSA. Eight patients (8%) required reintervention: 1 type IA endoleak, 1 type IB endoleak, 1 retrograde type A dissection, and 5 because of access-related complications. During a mean follow-up of 24±7.2 months, there were no aortic rupture, paraplegia, and all supra-aortic trunks were patent.

CONCLUSIONS

Double homemade fenestrated TEVAR is both feasible and effective for total endovascular aortic arch repair avoiding the need for anatomical and extra-anatomical surgical revascularization. The long-term durability will need to be assessed in studies with long-term follow-up.

CLINICAL IMPACT

Double homemade fenestrated TEVAR is effective for total endovascular aortic arch repair avoiding the need for anatomical and extra-anatomical surgical revascularization. The standout feature of this double fenestrated device is its simple handling during operation with the proximal fenestrations being directed to the orifices of the BT and LCCA automatically when the LSA fenestration is catheterized and secured by covered stent placement. The deployment algorithm actively steers the operator away from superfluous manipulations of the device within the arch and avoids guidewire manipulation in carotid arteries. The long-term durability will need to be assessed in studies with long-term follow-up.

Image Guidance Techniques and Treatment Approach Optimization in the Management of Type-II Endoleak After Endovascular Aortic Aneurysm Repair

BACKGROUND

Over the past 3 decades endovascular aortic aneurysm repair emerged as the primary approach for abdominal aortic aneurysm management, however the occurrence of endoleak following endograft implantation imposes a high toll on patients and hospitals alike. The early diagnosis and appropriate treatment of endoleaks is associated with better outcomes, which calls for more advanced imaging and a standardized approach for endoleak diagnosis and management following endovascular aortic aneurysm repair. Although conventional strategy with non-targeted deployment of coils and embolic material in the aneurysm sac is considered to be the standard approach in many hospitals, it may not prove to be a viable option, given that it affects any further follow-up imaging in the event of sub-optimal therapy and consequent recurrence.

METHODS

Based on our tertiary aortic referral center experience we summarize and describe strategies for optimal selection of various treatment approaches for Type-II Endoleak management including endovascular, percutaneous and laparoscopic approaches with particular focus on intraoperative image guidance techniques.

RESULTS

After failed conventional endovascular embolization attempt we recommend specific complex type II endoleak management approaches based on the location of the endoleak within the aneurysm sac along the x, y and z axis. A transabdominal or laparoscopic approach enable treatment in endoleaks located in the anterior portion of the sac. Endoleaks in the posterior portion of the sac could be treated using the transcaval or the translumbar approach, depending on whether the endoleak is situated on the left or the right side. Alternative strategies should be considered if patient anatomy does not allow for either transcaval or translumbar approach. The transgraft technique is reserved for endoleaks located in the cranial portion of the sac, while the perigraft approach could present a means of treatment for endoleaks situated in the caudal portion of the aneurysm sac.

CONCLUSION

We encourage establishing a patient specific treatment plan in accordance with individual anatomy based on cross sectional imaging modality (time resolved dynamic imaging in selected cases) and intraoperative image guidance to provide a safe and accurate endoleak localization and embolization for patients undergoing type II endoleak treatment.

First Case of Nellix Stent Rupture in a Huge Symptomatic Abdominal Aortic Aneurysm Who Underwent Endovascular Aneurysm Sealing 7 Years Before

PURPOSE

Despite encouraging early results, mid- and long-term follow-up of endovascular aneurysm sealing (EVAS) has shown increased rates of failure mainly associated with endoleak detection and progressive bag separation with aneurysm reperfusion.

CASE REPORT

We present the first case of a Nellix endograft stent fracture detected in a 91-year-old male patient, presenting with widespread abdominal pain, 7 years after elective treatment of an abdominal aortic aneurysm by EVAS. Considering the sudden and unexpected nature of the event, an in-depth analysis of the possible causes of this structural failure has been performed.

CONCLUSION

Material fatigue could be another significant cause of late EVAS failure and should be carefully assessed in addition to endoleak detection during follow-up.

CLINICAL IMPACT

The case presented in this article further underlines the importance of a strict long term follow-up protocol in every patients who underwent EVAS.

Endoleak in covered CP stent causes procedural failure during transcatheter closure of sinus venosus defects

Transcatheter sinus venosus defect closure uses a long covered stent of appropriate length and diameter across the cavoatrial junction after balloon interrogation. The fabric in the covered stent creates a roof for the right upper pulmonary vein that closes the interatrial communication and redirects the vein into the left atrium behind the stent. A fabric tear in the covered stent may cause endoleak that will result in residual flows across the struts of the covered stent, causing procedural failure. This report highlights the identification of fabric leak by angiography and transesophageal echocardiography and steps to overcome this complication by the placement of another overlapping covered stent.

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

PURPOSE

To evaluate the safety and effectiveness of intra-sac thrombin injection to remedy type II endoleaks (T2ELs) during endovascular aneurysm repair (EVAR).

MATERIALS AND METHODS

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.

RESULTS

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 ± 14.2 mm to 53.7 ± 10.6 mm, 47.9 ± 8.3 mm and 43.7 ± 7.2 mm (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 ± 136.2 cm3 to 202.6 ± 114.1 cm3, 155.6 ± 68.4 cm3 and 129.7 ± 52.4 cm3 (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.

CONCLUSIONS

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.

A Single-Institution Case Series of Total Endovascular Relining for Type 3 Endoleaks in Traditional Endovascular Aneurysm Repair (EVAR) Grafts with Raised Bifurcations

BACKGROUND

The endovascular repair of infrarenal abdominal aortic aneurysms can be performed with a wide variety of devices. Many of these grafts elevate the aortic bifurcation which can limit future repairs if the graft material fails thereby creating a type III endoleak to aorto-uniliac grafts. Many manufacturers have grafts susceptible to this, but we have seen this in the Medtronic AneuRx graft. Our goal is to provide technical details and outcomes regarding a novel technique to reline these grafts while maintaining inline flow to the iliac arteries.

METHODS

This was a single-institution review of patients who had endoleaks requiring intervention after a previously placed graft with an elevated aortic bifurcation. Primary outcomes included technical success defined as placement of all planned devices, resolution of type III endoleak, aneurysm size at follow-up, and requirement of reintervention. Secondary outcomes included 30-day complications, aneurysm-related mortality, and all-cause mortality. Technical details of the operation include back-table deployment of an Ovation device, modification of the deployment system tether and pre-emptive placement of an up and over 0.014″ wire. The wire is placed up and over and hung outside the contralateral gate. Once the main body is introduced above the old graft, the 0.014" is snared from the contralateral side and externalized. The main body is then able to be seated at the bifurcation as the limb is not fully deployed and then device deployment is completed per instructions for use.

RESULTS

Our study consists of 4 individuals, 3 of which had an abdominal aortic aneurysm initially managed with an AneuRx endovascular aneurysm repair and 1 with a combination of Gore and Cook grafts. All 4 patients were male with an average age of 84.5 years at time of reline. All patients had at least 10 years between initial surgery and reline at our institution. Primary outcomes revealed no type 1 or 3 endoleaks at follow-up, technical success was 100% and 1 patient required reintervention for aneurysm growth and type 2 endoleak. In terms of our secondary outcomes, there was 1 postoperative complication which was cardiac dysfunction secondary to demand ischemia, aneurysm-related mortality was 0% and all-cause mortality was 25% at average follow-up of 2.44 years.

CONCLUSIONS

As individuals continue to age, there are more patients who would benefit from less invasive reinterventions following endovascular aneurysm repair. Whether this is due to aortic degeneration, stent migration, or stent material damage is not always known. In this study, we present an endovascular approach to treating type III endoleak patients with a previous graft and elevated aortic bifurcation using Ovation stent grafts and found no evidence of type 1 or 3 endoleaks on follow-up imaging. This approach may allow patients with type III endoleak the option of a minimally invasive, percutaneous approach where they previously would not have had one.

[Partial Arch Repair for Reruptured Aortic Arch Aneurysm due to Endoleak After 2-debranching Thoracic Endovascular Aortic Repair:Report of a Case]

A 67-year-old male was admitted to our hospital for sudden onset chest pain and hoarseness. He underwent 2-debranching thoracic endovascular aortic repair for a ruptured aortic arch aneurysm four years prior. However, computed tomography (CT) revealed an aneurysmal rerupture due to a typeⅠa endoleak. We performed partial arch replacement with uncovered stent removal under intermittent hypothermic circulatory arrest. We needed to be more careful than usual open heart surgery because a non-anatomical bypass procedure was performed. The surgery was successful without any major complications, and the patient was discharged on the 23th postoperative day. Reinterventions post-endovascular repair are sometimes difficult;thus, open surgery could be useful for arch replacement.

Outcomes of Zone 1 Thoracic Endovascular Aortic Repair With Fenestrated Surgeon-Modified Stent-Graft for Aortic Arch Pathologies

OBJECTIVES

This study evaluated the feasibility and safety of zone 1 thoracic endovascular aortic repair (TEVAR) with fenestrated surgeon-modified stent-graft (SMSG) for aortic arch pathologies.

METHODS

Between March 2016 and November 2020, 34 consecutive patients underwent zone 1 TEVAR with fenestrated SMSG for aortic arch pathologies. Outcomes included technical success, perioperative, and follow-up morbidity and mortality.

RESULTS

During the study period, 34 patients were treated with zone 1 TEVAR with fenestrated SMSG. Twenty-four (70.6%) patients presented with type B aortic dissections, 9 (26.5%) patients presented with aneurysms (7 located on the lesser curvature side of aortic arch), 1 (2.9%) patient presented with type Ia endoleak after previous TEVAR owing to traumatic aortic dissection. The proximal landing zone for all patients were in zone 1, and all supra-aortic trunks were reconstructed, except for one left subclavian artery. Technical success was achieved in all cases. The 30-day estimated survival (±SE) was 90.9% ± 5.0% [95% confidence interval (CI): 77.0%-97.0%]. The 30-day estimated freedom from reintervention (±SE) was 87.9% ± 5.7% (95% CI: 73.4%-95.3%). At a median follow-up of 48 months (range, 12-68 months), 2 patients died, including 1 aortic-related death and 1 non-aortic-related death. One patient had reintervention 13 months after the operation owing to type Ia endoleak. All supra-aortic trunks were patent. The estimated survival (±SE) during follow-up was 85.1% ± 6.2% (95% CI: 69.9%-93.6%). One (2.7%) patient had stroke. The estimated freedom from reintervention (±SE) during follow-up was 84.2% ± 6.5% (95% CI: 69.9%-93.5%).

CONCLUSIONS

Zone 1 TEVAR with fenestrated SMSG is an alternate option for treatment of aortic arch pathologies in experienced centers.

Novel conformable stent-graft repair of abdominal aortic aneurysms with hostile neck anatomy: A single-centre experience

OBJECTIVES

Abdominal aortic aneurysms (AAAs) demonstrating hostile neck anatomy (HNA) are associated with increased perioperative risk and mortality. A number of these patients are not suitable for standard endovascular aneurysm repair (EVAR) and are high risk for open surgery. We present our experience with the first implantations in Scotland of a novel conformable aortic stent-graft designed to overcome some of the challenges of HNAs.

METHODS

From May 2018 to March 2022, 24 consecutive patients with non-ruptured AAAs demonstrating HNAs (neck length < 15 mm, or angulation > 60°) were treated with GORE Excluder Conformable AAA endoprosthesis (CLEVAR) (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) at a Scottish vascular centre. We assessed clinical outcomes and technical success of CLEVAR during deployment, primary admission and the post-operative period at 3- and 12-month clinical follow-up alongside CT angiography.

RESULTS

Twenty-four patients (20 males, mean age 75.6) were included. Primary technical success of proximal seal zones and CLEVAR deployment (no type 1/3 endoleaks, no conversion to open repair, AAA excluded and patient leaving theatre alive) was achieved in 100% of patients. All patients were alive and clinically stable at 3- and 12-month follow-up. There were five patients requiring re-intervention; at the 3-month follow-up, one patient (4.2%) developed a type 1b endoleak requiring graft limb extension, one patient developed a right common femoral artery dissection requiring open repair and one patient required a limb extension of the right iliac limb due to risk of developing a type 1b endoleak. At the 12-month follow-up, two patients required embolization of type 2 endoleaks and no patients demonstrated type 1 or type 3 endoleaks.Conclusions: In-hospital and post-operative 3- and 12-month clinical and angiographic outcomes demonstrate safety and efficacy with CLEVARs in treating unruptured AAAs with HNA. Further research involving larger heterogenous sample sizes is warranted to determine long-term clinical outcomes.

Long-Term Outcomes of Simple Endovascular Aneurysm Repair Based on the Initial Aortic Diameter

PURPOSE

We aimed to investigate the effects of initial abdominal aortic aneurysm (AAA) diameter on aneurysmal sac expansion/shrinkage, endoleaks, and reintervention postelective simple endovascular aneurysm repair (EVAR).

METHODS

Overall, 228 patients monitored for >1 year after EVAR were analyzed. Male and female participants with initial AAA diameters <55 mm and <50 mm, respectively, composed the small group (group S), while those with initial AAA diameters ≥55 mm (men) and ≥50 mm (women) composed the large group (group L). Aneurysmal sac expansion of 10 mm and/or reintervention during follow-up (composite event) and its related factors were evaluated.

RESULTS

The 5-year freedom from composite event rate was significantly higher in group S (92.4 ± 2.8%) than that in group L (79.1 ± 4.9%; P <0.01). Multivariate analysis revealed AAA diameters before EVAR in group S (hazard ratio, 0.38; 95% confidence interval, 0.18-0.81; P = 0.01) and type II endoleak (T2EL) at discharge (hazard ratio, 2.83; 95% confidence interval, 1.29-6.20; P <0.01) as factors associated with the composite event. The freedom from composite event rate decreased to 51 ± 13% at 5 years in group L with T2EL.

CONCLUSIONS

Group S had high freedom from composite event rate; in group L, the rate decreased to 51% at 5 years with T2EL at discharge.

Endovascular aortic repair with sac embolization for the prevention of type II endoleaks (the EVAR-SE study): study protocol for a randomized controlled multicentre study in Germany

BACKGROUND

Beyond a certain threshold diameter, abdominal aortic aneurysms (AAA) are to be treated by open surgical or endovascular aortic aneurysm repair (EVAR). In a quarter of patients who undergo EVAR, inversion of blood flow in the inferior mesenteric artery or lumbar arteries may lead to type II endoleak (T2EL), which is associated with complications (e.g. AAA growth, secondary type I endoleak, rupture). As secondary interventions to treat T2EL often fail and may be highly invasive, prevention of T2EL is desirable. The present study aims to assess the efficacy of sac embolization (SE) with metal coils during EVAR to prevent T2EL in patients at high risk.

METHODS

Over a 24-month recruitment period, a total of 100 patients undergoing EVAR in four vascular centres (i.e. Klinikum rechts der Isar of the Technical University of Munich, University Hospital Augsburg, University Hospital Dresden, St. Joseph's Hospital Wiesbaden) are to be included in the present study. Patients at high risk for T2EL (i.e. ≥ 5 efferent vessels covered by endograft or aneurysmal thrombus volume <40%) are randomized to one group receiving standard EVAR and another group receiving EVAR with SE. Follow-up assessments postoperatively, after 30 days, and 6 months involve contrast-enhanced ultrasound scans (CEUS) and after 12 months an additional computed tomography angiography (CTA) scan. The presence of T2EL detected by CEUS or CTA after 12 months is the primary endpoint. Secondary endpoints comprise quality of life (quantified by the SF-36 questionnaire), reintervention rate, occurrence of type I/III endoleak, aortic rupture, death, alteration of aneurysm volume, or diameter. Standardized evaluation of CTA scans happens through a core lab. The study will be terminated after the final follow-up visit of the ultimate patient.

DISCUSSION

Although preexisting studies repeatedly indicated a beneficial effect of SE on T2EL rates after EVAR, patient relevant outcomes have not been assessed until now. The present study is the first randomized controlled multicentre study to assess the impact of SE on quality of life. Further unique features include employment of easily assessable high-risk criteria, a contemporary follow-up protocol, and approval to use any commercially available coil material. Overcoming limitations of previous studies might help SE to be implemented in daily practice and to enhance patient safety.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05665101. Registered on 23 December 2022.

Transcaval Coil Embolization of Type 2 Endoleak After Endovascular Aortic Repair: An Institutional Review

OBJECTIVES

Endovascular aortic repair may be complicated by type 2 endoleaks. Intervention is generally recommended when the native sac continues to grow more than 5 mm. Transcaval coil embolization (TCE) of the native aneurysm sac is an emerging technique for repair of type 2 endoleaks. The objective of this study is to report an institutional review of our experience with this technique.

METHODS

11 patients underwent TCE during the study period. Data were gathered on demographics, size increase of native aneurysm sac, operative details, and outcomes. Technical success was defined as resolution of the endoleak during completion sac angiogram at end of the procedure. Clinical success was defined as no growth in the aneurysm sac at interval follow-up.

RESULTS

Coils were the embolant of choice in all cases. Technical success was achieved in all cases except 1 resulting in a 91% technical success rate. Median follow-up was 25 months (range, 3-33). Of the ten patients that had technically successful embolization, 8 patients had repeat computed tomography (CT) scans which showed no further expansion of the native sac resulting in a 80% clinical success rate. No complications were noted immediately post-op or at interval follow-up.

CONCLUSIONS

This institutional retrospective review demonstrates that TCE is an effective and safe option for type 2 endoleaks after endovascular aortic repair (EVAR) in selected patients with favorable anatomy. Longer term follow-up, more patients, and comparison studies are needed to further define durability and efficacy.

Results of the Chimney Technique in a Community Hospital

BACKGROUND

The chimney technique, fenestrated or branched endovascular aortic repair are endovascular options in patients with a juxtarenal, suprarenal or type IV thoraco-abdominal aneurysm. The chimney technique has specific advantages and disadvantages. A retrospective single center study was performed to describe the results.

PATIENTS AND METHODS

All consecutive patients in whom the chimney technique was used between 1th January 2011 and 31th December 2020 were included. We excluded patients who needed a revision of an existing EVAR and patients with a para-anastomotic aneurysm. Outcomes were reported in accordance with the reporting standards.

RESULTS

38 Patients were included in the study, a total of 59 chimney grafts were deployed. At a median follow-up duration of 26.6 months, there were 9 patients with occlusion of the chimney graft. In 1 patient an iliac renal bypass was performed. In the other patients the renal function stabilized and no further therapy was necessary. All chimneys in the mesenteric arteries remained patent. Gutter endoleak was seen in 5 patients, 3 patients were successfully treated and in the other 2 patients the gutter endoleak disappeared spontaneously.

CONCLUSIONS

Conclusions should be drawn carefully as this is a retrospective non-comparative study. Results from 38 patients treated with the chimney technique are presented. Chimney graft occlusion rate was 15.3% at the end of follow-up. However, the majority (77.8%) of the occluded stents were self-expandable stents, stressing the importance of selecting the right devices.

Prevalence of type II endoleak after elective endovascular aneurysm repair with polytetrafluoroethylene- or polyester-based endografts

OBJECTIVE

Type II endoleak is the most frequent complication after endovascular abdominal aneurysm repair. Polytetrafluoroethylene and polyester (PE) are the two most commonly used graft materials in endovascular aneurysm repair (EVAR) devices. Biological properties of the material might influence the appearance and persistence of type II endoleak (T2EL). Therefore, the aim of this study was to evaluate potential differences in the prevalence of T2EL after EVAR between polytetrafluoroethylene (PTFE) and PE endografts in patients electively treated for an infrarenal abdominal aortic aneurysm.

METHODS

A single-center, retrospective, observational study was conducted between January 2011 and January 2022. Preoperative, procedural, and follow-up data were derived from electronic health records. Imaging included computed tomography scans, and/or duplex ultrasound examination. The primary end point was the prevalence of T2EL diagnosed within 1 year after EVAR. Secondary end points included the prevalence of T2EL throughout follow-up, early (≤30 days) and late (>30 days) T2EL, the rate of T2EL disappearance during the follow-up period, the prevalence of type I and III endoleak, and T2EL-related reinterventions.

RESULTS

Follow-up was available for 394 patients, 245 in the PE and 149 in the PTFE group. The prevalence of T2EL diagnosed within 1 year after endovascular repair was 11.8% in the PE group and 21.5% in the PTFE group (P = .010). There was no significant difference in early (≤30 days) and late (>30 days) T2EL between groups (P = .270 and P = .311). There was no difference in the freedom from endoleak type II reinterventions between groups (P = .877).

CONCLUSIONS

The prevalence of T2EL after elective EVAR is significantly higher with the use of PTFE-based endografts compared with PE-based endografts. This difference is mostly based on T2EL diagnosed after 30 days of follow-up.

Predictive Parameters of Type 1A Endoleak for Elective Endovascular Aortic Repair: A Single-Center Experience

BACKGROUND

One of the most important factors that affects the success of Endovascular Aortic Repair (EVAR) treatment is the morphology of the neck of the aneurysm. Today, EVAR can be performed even in patients who do not meet the Instruction For Use criteria with hostile neck risk factors; thanks to the developing experience and technology. Our aim in this study was to determine risk factors for Type 1a endoleaks in patients who underwent EVAR and predictive factors for Type 1a endoleaks in patients with combinations of these risk factors.

METHODS

Patients who underwent elective EVAR for infrarenal abdominal aortic aneurysm in our medical center between July 2016 and January 2021 were enrolled. Of these 244 patients, 180 patients with documented preoperative and postoperative computed tomographic angiography results and a follow-up of at least 1 year were included in the study. The Mann-Whitney U test and Student's t-test were used to assess the relationship between nominal data and numerical values, and the t-test and Wilcoxon test were used to compare dependent groups. Logistic regression analysis was performed to model risk factors associated with endoleaks.

RESULTS

The results showed that a neck length less than 15 mm increased the development of type 1a endoleak by 10.4 times (P < 0.001). Furthermore, a neck diameter more than 28 mm increased the development of type 1a endoleak by 21.9 times (P = 0.04). A conical neck structure (gradual neck dilation > 2 mm) increased the development of type 1a endoleaks 4.8 times (P = 0.04). The presence of calcification (> 150 Hounsfield Unit and > 2 mm) in the neck increased the risk of type 1a endoleaks fourfold (P = 0.04). Hostile neck parameters were analyzed and patients with only 1 parameter (n = 69) had a 7.2% type 1a endoleak rate, while patients with 2 parameters (n = 15) had 26.6% and patients with more than 2 parameters (n = 11) had 45.5% type 1a endoleak rate.

CONCLUSIONS

Morphologic features of the neck structure of the aneurysm are among the most important parameters that affect the success of EVAR treatment. Alternative treatments should be considered in patients with more than 1 unfavorable neck parameter.

Endograft position and endoleak detection after endovascular abdominal aortic repair with low-field tiltable MRI: a feasibility study

BACKGROUND

Abdominal aortic endoleaks after endovascular aneurysm repair might be position-dependent, therefore undetectable using supine imaging. We aimed to determine the feasibility and benefit of using a low-field tiltable magnetic resonance imaging (MRI) scanner allowing to study patients who can be imaged in both supine and upright positions of endoleaks.

METHODS

Ten EVAR patients suspected of endoleak based on ultrasound examination were prospectively included. MRI in upright and supine positions was compared with routine supine computed tomography angiography (CTA). Analysis was performed through (1) subjective image quality assessment by three observers, (2) landmark registration between MRI and CTA scans, (3) Euclidean distances between renal and endograft landmarks, and (4) evaluation of endoleak detection on MRI by a consensus panel. Statistical analysis was performed by one-way repeated measures analysis of variance.

RESULTS

The image quality of upright/supine MRI was inferior compared to CTA. Median differences in both renal and endograft landmarks were approximately 6-7 mm between upright and supine MRI and 5-6 mm between supine MRI and CTA. In the proximal sealing zone of the endograft, no differences were found among all three scan types (p = 0.264). Endoleak detection showed agreement between MRI and CTA in 50% of the cases, with potential added value in only one patient.

CONCLUSIONS

The benefit of low-field upright MRI for endoleak detection was limited. While MRI assessment was non-inferior to standard CTA in detecting endoleaks in selected cases, improved hardware and sequences are needed to explore the potential of upright MRI in patients with endoleaks.

RELEVANCE STATEMENT

Upright low-field MRI has limited clinical value in detecting position-dependent endoleaks; improvements are required to fulfil its potential as a complementary modality in this clinical setting.

KEY POINTS

• Upright MRI shows potential for imaging endoleaks in aortic aneurysm patients in different positions. • The image quality of upright MRI is inferior to current techniques. • Upright MRI complements CTA, but lacks accurate deformation measurements for clinical use. • Advancements in hardware and imaging sequences are needed to fully utilise upright MRI capabilities.

Utility of 4D CT in endoleak characterization after advanced endovascular aortic repair

OBJECTIVES

To assess the performance of dynamic or 4D CT in characterizing endoleaks in advanced endovascular aortic repair (branched and fenestrated) when other modalities fail to fully characterize the leak, most often conventional CTA.

METHODS

Retrospective review of 13 patients from 2008 to 2021 who underwent 16 4D CTs to characterize endoleaks in branched and fenestrated endovascular aortic repair (FB-EVAR). The 4D CTs were performed covering up to 16 cm of the z-axis, with anywhere between 10 and 40 iterations performed every 2 s. These settings were adjusted depending on graft characteristics and type of endoleak suspected. The scans were assessed for their ability to detect the endoleak (sensitivity), and further to characterize the endoleak by type and subtype (specificity).

RESULTS

Overall sensitivity in 16 scans for endoleak detection was 100%. There was a specificity of 87.5% for determining the type of endoleak (14/16). These results included two studies that were inconclusive and repeated due to technical difficulties. In patients where a specific subtype was not established, the leak was localized to the appropriate target vessel. Average dose for the 4D CT was 4724 mGy*cm (1108-11069), with the outlining higher dose scans secondary to higher iterations in those scans.

CONCLUSIONS

4D CT is a useful adjunctive tool in FB-EVAR surveillance with excellent sensitivity and specificity in characterizing endoleaks. This allows for accurate localization of leaks, which is critical for management planning.

Improved Detection of Endoleaks in Virtual Monoenergetic Images in Dual-Energy CT Angiography Following EVAR

OBJECTIVES

The objective of this prospective study was to evaluate the virtual monoenergetic images (VMI) and virtual noncontrast (VNC) phase in the detection of endoleaks after endovascular abdominal aortic repair (EVAR). The potential dose reduction of abbreviated examination protocols was calculated.

MATERIALS AND METHODS

Ninety-seven patients after the EVAR procedure were enrolled in this study. An initial single-source noncontrast acquisition was followed by two dual-energy acquisitions (arterial and 60 s delayed). Fast-kVp switching scanner was used. VNC images were reconstructed from the delayed phase. First examination session (reference) included a full triphasic study protocol consisting of true noncontrast (TNC) images and two postcontrast phases, the latter ones presented as classical polyenergetic reconstructions. Reading sessions II and III were performed by two independent and blinded readers evaluating VMIs in abbreviated protocols-biphasic (VNC + arterial, delayed phase), monophasic (VNC + delayed phase). The diagnostic accuracy of sessions II and III was calculated.

RESULTS

The calculated sensitivity of the biphasic protocol with the use of VMIs in endoleak detection was 100%, with a statistically significant increase in the number of endoleaks detected in comparison with the reference study. The monophasic protocol showed 83.33% sensitivity. The use of abbreviated examination protocols led to a decrease in the mean effective dose (ED) of 23.28% (biphasic protocol) and 61.37% (monophasic protocol).

CONCLUSION

The use of VMIs increases the number of endoleaks diagnosed with a possible radiation reduction by up to ¼ (biphasic protocol). Further reduction to a monophasic protocol leads to over 60% dose reduction but with a decrease in diagnostic accuracy.

Traumatic Endograft Fracture With Subsequent Type IIIb Endoleak

Abdominal aortic aneurysm (AAA) repair is commonly treated via endovascular aneurysm repair (EVAR). A known complication of EVAR is an endoleak: types I to IV. Type III endoleaks have been shown to have a relative risk of 8.95 for late rupture requiring prompt treatment. These endoleaks have been found to be caused by over dilation of the main body causing graft fabric distortion, fractures of metallic struts, fabric wear from chronic micromotion, fabric tears, and suture breakage. We present a case of traumatic EVAR fracture with subsequent type IIIb endoleak after blunt abdominal trauma. This highlights the need for close evaluation of endografts after abdominal trauma. These traumatic events can lead to traumatic fracture of endografts creating endoleaks that if not treated promptly can lead to rupture.

Factors Influencing Compliance to Follow-Up After Endovascular Aneurysm Repair

OBJECTIVES

Regular follow-up after endovascular repair of aortic aneurysm is necessary to detect endoleak and/or migration of the stentgraft. However, absence or incomplete compliance to follow-up is common in this patient population. In this study we will analyse the frequency of non-compliance to post-EVAR follow-up and explore the underlying reasons.

METHODS

All patients undergoing EVAR for infrarenal aortic aneurysm between 1st January 2011 and 31st December 2020 were included in this retrospective study. Absence of compliance to FU was defined as not showing up at the out-patient clinic; incomplete FU was defined as a surveillance gap of >18 months.

RESULTS AND CONCLUSION

Non-compliance to follow-up was 35.9% (175 patients). In the multivariate analysis the patients who came with a ruptured aneurysm and patients who needed secondary therapy in the first 30 days more often did not comply with the FU protocol (P = .03 and P < .01). Other studies have confirmed the low attendance to follow-up after EVAR.

Photon-Counting Detector CT Angiography for Endoleak Detection After Endovascular Aortic Repair: Triphasic CT With True Noncontrast Versus Biphasic CT With Virtual Noniodine Imaging

OBJECTIVES

The aim of this study was to compare image quality and endoleak detection after endovascular abdominal aortic aneurysm repair between a triphasic computed tomography (CT) with true noncontrast (TNC) and a biphasic CT with virtual noniodine (VNI) images on photon-counting detector CT (PCD-CT).

MATERIALS AND METHODS

Adult patients after endovascular abdominal aortic aneurysm repair who received a triphasic examination (TNC, arterial, venous phase) on a PCD-CT between August 2021 and July 2022 were retrospectively included. Endoleak detection was evaluated by 2 blinded radiologists on 2 different readout sets (triphasic CT with TNC-arterial-venous vs biphasic CT with VNI-arterial-venous). Virtual noniodine images were reconstructed from the venous phase. The radiologic report with additional confirmation by an expert reader served as reference standard for endoleak presence. Sensitivity, specificity, and interreader agreement (Krippendorf α) were calculated. Image noise was assessed subjectively in patients using a 5-point scale and objectively calculating the noise power spectrum in a phantom.

RESULTS

One hundred ten patients (7 women; age, 76 ± 8 years) with 41 endoleaks were included. Endoleak detection was comparable between both readout sets with a sensitivity and specificity of 0.95/0.84 (TNC) versus 0.95/0.86 (VNI) for reader 1 and 0.88/0.98 (TNC) versus 0.88/0.94 (VNI) for reader 2. Interreader agreement for endoleak detection was substantial (TNC: 0.716, VNI: 0.756). Subjective image noise was comparable between TNC and VNI (4; IQR [4, 5] vs 4; IQR [4, 5], P = 0.44). In the phantom, noise power spectrum peak spatial frequency was similar between TNC and VNI (both f peak = 0.16 mm -1 ). Objective image noise was higher in TNC (12.7 HU) as compared with VNI (11.5 HU).

CONCLUSIONS

Endoleak detection and image quality were comparable using VNI images in biphasic CT as compared with TNC images in triphasic CT offering the possibility to reduce scan phases and radiation exposure.

Leiomyosarcoma Presenting as Rupture With a Type II Endoleak After Thoracic Endovascular Aortic Repair

Endovascular stent-graft therapy is a commonly performed procedure for aortic lesions worldwide and complications unique to stent grafts, such as postoperative endoleaks, are well known. However, as this treatment modality becomes more popular, physicians should carefully monitor for other unexpected complications, which may not always be related to the graft. This study presents a case of leiomyosarcoma of the aorta that developed during follow-up for a type II endoleak (T2EL) after thoracic endovascular aortic repair. The presence of the T2EL hindered the diagnosis of the sarcoma at an early stage. These findings suggest that an apparent aneurysm that grows suddenly during follow-up after stent grafting should raise the index of suspicion for a neoplasm as well as an endoleak.

Midterm Outcomes of Primary and Secondary Use of an Endoanchor System for Thoracic and Abdominal Aortic Endovascular Aortic Repair

PURPOSE

To assess the safety, technical success, and midterm outcomes of endoanchor (Heli-FX, Medtronic, Santa Rosa, California) deployment in thoracic endovascular aortic repair (TEVAR) or abdominal endovascular aortic repair (EVAR).

MATERIALS AND METHODS

This single-institution, retrospective study of all endoanchor procedures was performed from February 1, 2017 to March 30, 2021. All procedures were performed percutaneously by interventional radiologists. Clinical information and outcome data were retrieved from electronic medical records. Fifty patients (14% females, n = 7; 86% males, n = 43; median age, 79 years [range, 56-93 years]) underwent Endoanchor procedures, with 349 Endoanchors implanted; 33 procedures were primary deployments (at initial stent deployment) and 17 were secondary deployments (previous stent deployment). For the primary group (4 TEVARs and 29 EVARs), indications were prophylactic (n = 30), hostile neck (n = 28), hostile distal landing zone (n = 2), and intraprocedural type 1a endoleaks (n = 3). For the secondary group (4 TEVARs and 13 EVARs), indications were graft migration (n = 8), seal zone expansion without proven endoleak (n = 7) (proximal [n = 4] or distal seal [n = 3]), and proven type 1a endoleak (n = 2).

RESULTS

Median number of endoanchors deployed per procedure was 7 (range, 3-10). Median time to deploy endoanchors was 22 minutes (range, 8-46 minutes). The technical success rate of Endoanchor was 99.7% (348/349). The 30-day mortality rate was 0%. The overall adverse event rate was 6% (n = 3). Reinterventions were performed in 12% of patients (n = 6). Median follow-up was 38 months (range, 2-71 months). Overall survival at 1 and 3 years was 95% and 85%, respectively. Overall freedom from type 1a endoleak at 1 and 3 years was 96% and 93%, respectively.

CONCLUSIONS

Endoanchor procedures are safe with excellent technical success rate and good midterm clinical outcomes.

Disseminated Intravascular Coagulation Post Endovascular Aortic Repair

BACKGROUND

Disseminated Intravascular Coagulation (DIC) after Endo-Vascular Aneurysm Repair (EVAR) is a highly uncommon clinical entity. With only a few case-reports available, its management strategy still remains enigmatic.

OBJECTIVES

The purpose of this study was to retrieve, synthesize, and appraise all existing data for DIC after EVAR.

MATERIALS AND METHODS

All published articles regarding DIC post-EVAR were identified from 3 major databases and analyzed. Clinical parameters, predisposing factors, along with mortality and morbidly were assessed.

RESULTS

The total number of publications included in the review was 15 describing 17 cases. DIC presented with a broad spectrum of clinical manifestations, while the time of diagnosis varied significantly. Endoleak was the main causative factor, with an incidence reaching 71%. The mortality of DIC after EVAR reached 29%, regardless of the therapeutic approach chosen. DIC was treated effectively in 47% of the patients (8/17), with better outcomes among patients who received conservative therapy or among those who were submitted to endovascular interventions.

CONCLUSIONS

DIC after EVAR, although rare, is a potentially lethal clinical condition which requires prompt diagnosis and urgent medical consideration. Treatment of endoleak may help in quick restoration of normal parameters.

Impact of Patent Lumbar Arteries on Aneurysm Sac Enlargement with Type II Endoleak after Endovascular Aneurysm Repair

OBJECTIVE

This study aimed to investigate the impact of the number of patent lumbar arteries (LAs) on sac enlargement after endovascular aneurysm repair (EVAR).

METHODS

This was a retrospective cohort single centre registry study. Between January 2006 and December 2019, 336 EVARs were reviewed using a commercially available device excluding type I or type III endoleaks during a follow up of ≥ 12 months. Patients were divided into four groups based on the pre-operative patency of the inferior mesenteric artery (IMA) and high (≥ 4) or low (≤ 3) number of patent LAs: Group 1, patent IMA and high number of patent LAs; Group 2, patent IMA and low number of patent LAs; Group 3, occluded IMA and a high number of patent LAs; Group 4, occluded IMA and low number of patent LAs.

RESULTS

Groups 1, 2, 3, and 4 included 124, 104, 45, and 63 patients, respectively. The median follow up duration was 65.1 months. Significant differences in the incidence of overall type II endoleak (T2EL) at discharge between Group 1 and Group 2 (59.7% vs. 36.5%, p < .001) and between Group 3 and Group 4 (33.3% vs. 4.8%, p < .001) were observed. In patients with a pre-operatively patent IMA, the rate of freedom from aneurysm sac enlargement was significantly lower in Group 1 than in Group 2 (69.0% vs. 81.7% five years after EVAR, p < .001). In patients with a pre-operatively occluded IMA, the freedom rate from aneurysm sac enlargement was not significantly different between Groups 3 and Group 4 (95.0% vs. 100% five years after EVAR, p = .075).

CONCLUSION

A high number of patent LAs seemed to have a significant role in sac enlargement with T2EL when the IMA was patent pre-operatively, whereas a high number of patent LAs seemed to have limited influence on sac enlargement when the IMA was occluded pre-operatively.

Re-Rupture 2 Years after Endovascular Aortic Aneurysm Repair Rupture

Re-rupture 2 years after endovascular aortic aneurysm repair (EVAR) rupture is an extremely rare event and limited data exist in the literature. We present an interesting case of a patient with an abdominal aortic rupture that had undergone 2 years before an endovascular repair for rupture after EVAR due to a type IA endoleak. The patient underwent a successful embolization of the type IA endoleak. Onyx was used to seal the gutter between the aortic wall and the endograft and the 1-month post-embolization CT showed complete sealing with no contrast in the sac. Two years after the rupture, he was presented again with clinical signs of hemodynamic shock and instability. An urgent CT Angiograph showed again rupture due to a type IA endoleak. The patient underwent an emergency open laparotomy. We analyze the re-rupture after EVAR while taking data from the literature into account.

Combining Endovascular Aneurysm Sealing with Chimney Grafts - 5 Year Follow-Up after 47 Procedures

BACKGROUND

To evaluate longer-term results of a cohort treated with primary chimney endovascular aneurysm sealing (ChEVAS) for complex abdominal aortic aneurysms or secondary ChEVAS after failed endovascular aneurysm repair/endovascular aneurysm sealing.

METHODS

A single-center study was conducted of 47 consecutive patients (mean age 72 ± 8 years, range 50-91; 38 men) treated with ChEVAS from February 2014 to November 2016 and followed through December 2021. The main outcome measures were all-cause mortality (ACM), aneurysm-related mortality, occurrence of secondary complications and conversion to open surgery. Data are presented as the median (interquartile range [IQR]) and absolute range.

RESULTS

35 patients received a primary ChEVAS (=group I) and 12 patients a secondary ChEVAS (=group II). Technical success was 97% (group I) and 92% (group II); 30-day mortality was 3% and 8%, respectively. The median proximal sealing zone length was 20.5 mm (IQR 16, 24; range 10-48) in group I and 26 mm (IQR 17.5, 30; range 8-45) in group II, respectively. During a median time of follow-up of 62 months (range 0-88), ACM amounted to 60% (group I) and 58% (group II); aneurysm mortality was 29% and 8%, respectively. An endoleak was seen in 57% (group I: 15 type Ia endoleaks, four isolated type Ib, and 1 endoleak type V) and 25% (group II: 1 endoleak type Ia, one type II, and 2 type V), aneurysm growth in 40% and 17%, migration in 40% and 17%, resulting in 20% and 25% conversions in group I and II, respectively. Overall a secondary intervention was performed in 51% (group I) and 25% (group II), respectively. The occurrence of complications did not significantly differ between the 2 groups. Neither the number of chimney grafts, nor the thrombus ratio significantly affected the occurrence of abovementioned complications.

CONCLUSIONS

While initially delivering a high technical success rate, ChEVAS fails to provide acceptable longer-term results both in primary and secondary ChEVAS, resulting in high rates of complications, secondary interventions and open conversions.

Early- and Mid-Term Results of Abdominal Endovascular Aneurysm Repair Using an Aortic Cuff Prior to the Main Body to Prevent Type II Endoleaks

PURPOSE

Postoperatively persistent type II endoleaks (T2ELs) in abdominal endovascular aneurysm repair (EVAR) are known risk factors for long-term aneurysm enlargement. Therefore, various measures have been proposed to prevent T2ELs. Notably, the Kilt technique, which can be used in patients with dumbbell-shaped morphology, employs an aortic cuff deployed in the distal seal zone before the main body. Although previous studies have successfully applied this technique for preventing T2ELs, the mid- and long-term outcomes remain unclear. This study aimed to report the early- to mid-term outcomes in cases where an aortic cuff technique was used to prevent T2ELs.

MATERIALS AND METHODS

This retrospective single-center study analyzed 9 patients (mean age, 79 years; range, 69-88 years; 8 men) with abdominal aortic aneurysms. All patients underwent EVAR using an aortic cuff to prevent T2ELs. The primary end points were technical success (successful deployment) and clinical success (no T2ELs). Secondary end points included morbidity, reintervention, and aortic remodeling during follow-up.

RESULTS

The technical success rate was 100%. There were no intraprocedural or postoperative complications. No deaths or reinterventions occurred. Postoperative computed tomography showed no endoleaks in 6 patients, while T2ELs from the lumbar artery outside the aortic cuff deployment range were noted in 3 patients. However, no T2ELs were observed in the artery in the aortic cuff deployment range in any patient. The average number of successfully occluded arteries was 4.2 (range, 2-8). All patients had follow-up >6 (mean, 18.6; range, 6-36) months. Aneurysm sac shrinkage occurred in 5 patients during the follow-up period, whereas aneurysm size was stable in 3 patients. In contrast, only 1 patient showed transient dilation of the aneurysm sac enlargement; however, this dilation remained unchanged even after 1.5 years.

CONCLUSION

The aortic cuff technique is a favorable endovascular method for preventing T2ELs in EVAR. The present study showed that a single aortic cuff could easily and reliably occlude arteries branched from the aneurysm sac.

Detection of Endoleaks Following Thoracic and Abdominal Aortic Endovascular Aortic Repair-: A Comparison of Standard and Dynamic 4D-Computed Tomography Angiography

PURPOSE

Endoleaks are a common complication after endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR). The detection and correct classification of endoleaks is essential for the further treatment of affected patients. However, standard computed tomography angiography (CTA) provides no hemodynamic information on endoleaks, which can result in misclassification in complex cases. The aim of this study was to compare standard CTA (sCTA) with dynamic, dual-energy CTA (dCTA) for detection and classification of endoleaks following EVAR or TEVAR.

MATERIALS AND METHODS

This retrospective evaluation compared 69 sCTA diagnostic examinations performed on 50 different patients with 89 dCTA diagnostic examinations performed on 69 different patients.

RESULTS

In total, 15.9% of sCTA examinations and 49.4% of dCTA examinations led to the detection of endoleaks. With sCTA, 20.0% of patients were diagnosed with endoleaks, while with dCTA, 37.7% of patients were diagnosed with endoleaks. With sCTA, mainly Type 1 endoleaks were detected, whereas, with dCTA, the types of detected endoleaks were more evenly distributed. In comparison with the literature, the frequencies of endoleak types detected with dCTA better reflect the natural distribution than the frequencies detected with standard CTA.

CONCLUSION

Based on the retrospective comparative evaluation, dCTA could pose a valuable supplementary diagnostic tool resulting in a more accurate and realistic detection and classification of suspected endoleaks.

Use of the Endoleak-to-Aortic Density Ratio to Distinguish Direct Endoleaks from Indirect Endoleaks after Endovascular Aortic Aneurysm Repair

PURPOSE

To define criteria to distinguish direct (type 1 or 3) from indirect endoleaks (type 2) in the arterial phase of contrast-enhanced computed tomography (CT) scans in patients with abdominal aortic aneurysms treated with endovascular aortic repair.

MATERIALS AND METHODS

This retrospective study was conducted from January 2009 to October 2020 and included consecutive patients treated endovascularly for a direct endoleak or an indirect endoleak associated with an enlarging aneurysm. The following characteristics were evaluated using contrast-enhanced CT: location, size, contact with the endograft, density, morphologic criteria, collateral artery enhancement, and endoleak-to-aortic density ratio. Statistical analysis included the Mann-Whitney U test, Pearson χ2 test, Fisher exact test, receiver operating characteristic curve analysis, and multivariable logistic regression.

RESULTS

Contrast-enhanced CT scans from 71 patients (87% men), who presented with 87 endoleaks (44 indirect and 43 direct endoleaks), treated by endovascular techniques were analyzed. Using visual criteria, 56% of the endoleaks were not characterizable as direct or indirect. An endoleak-to-aortic density ratio of >0.77 could properly distinguish direct from indirect endoleaks, with a theoretical accuracy of 98% (area under the receiver operating characteristic curve, 0.99), sensitivity of 95%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 96%.

CONCLUSION

An endoleak-to-aortic density ratio of >0.77 in the arterial phase of contrast-enhanced CT could be a strong discriminant of a direct-type endoleak.