Best Practice Guidelines: Imaging Surveillance After Endovascular Aneurysm Repair

Ultrasound Contrast Agents: Current Role in Adults and Children for Various Indications

Intravenous contrast-enhanced ultrasound (CEUS) is a rapidly evolving imaging technique that uses a microbubble contrast agent to enhance ultrasonographic images by augmenting characterization of blood vessels and organ perfusion. CEUS is considered as a useful problem-solving tool and as an indicated first-line imaging modality in select settings. CEUS technique has an inherent advantage over its predecessor B-mode and Doppler imaging. This article reviews different approved and off-label use of CEUS in the pediatric and adult population and also discusses Food and Drug Administration-approved contrast agents in the United States, their reported side effects, and ongoing efforts in the field.

Technical and clinical success analysis of transarterial embolization therapy in type II endoleaks following endovascular aortic repair

This single-center study investigated the safety and efficacy of transarterial embolization of type II endoleaks for expanding aneurysm sacs following endovascular aortic repair (EVAR).36 patients (33 men, 75.9±6.6 years) underwent a total of 50 endovascular procedures for type II endoleak embolization between 2008 and 2023. Analyses included the assessment of patient risk profiles, aneurysm morphology, and endoleak characteristics. Outcome parameters comprised the technical success (i.e., complete lack of blood flow in the previously perfused aneurysm sac) and complication rates, while clinical success was defined as the absence of endoleak persistence or recurrence and freedom from aneurysm enlargement > 0.5 cm over the follow-up period.Transarterial embolization was technically successful in 84% of procedures with a complication rate of 2%. Most interventions were coil-based (72%), while a small number relied solely on liquid embolic agents (14%). Absence of a persisting endoleak in the earliest follow-up could be demonstrated in 75.6% of cases, whereas the absence rate for endoleak recurrence was substantially lower (46.3%). No aneurysm enlargement > 0.5 cm during follow-up was ascertained after 73.2% of interventions.Transarterial embolization represents a safe treatment for type II endoleaks after EVAR. While embolization was moderately effective in preventing further expansion of aneurysms due to endoleak recurrence, most procedures were successful in permanently eliminating the targeted feeder vessels. · Transarterial embolization of type II endoleaks has a high technical success rate.. · The emergence of new feeder vessels may necessitate multiple procedures over time.. · Patient risk profiles did not factor into the clinical outcome.. · Krompaß K, Grunz JP, Augustin AM et al. Technical and clinical success analysis of transarterial embolization therapy in type II endoleaks following endovascular aortic repair. Fortschr Röntgenstr 2024; DOI 10.1055/a-2384-4601.

Late post-EVAR abdominal aortic aneurysm rupture: a meta-analysis study

This study presents updated information on post-endovascular aneurysm repair (EVAR) late aortic rupture (LAR) as the data in the literature are limited. It comprises a meta-analysis based on the recent evidence regarding the incidence, causes, treatment outcomes, and prognosis of post-EVAR. A meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were identified by searching electronic databases and scanning bibliographic references from 1991 to April 1, 2023. Our analysis provided evidence that the most common causes of rupture after EVAR were type Ia and Ib Endoleaks (Els). Post-rupture mortality after EVAR was high (35.6%) and comparable to the morbidity of de novo ruptures. Endovascular repair appears to have better results compared to conversion to open repair. A significant number of patients had prior endovascular reoperations and inadequate follow-up. Patient compliance with the surveillance protocol is mandatory.

Enhancing image quality in computed tomography angiography follow-ups after endovascular aneurysm repair: a comparative study of reconstruction techniques

BACKGROUND

The image quality of computed tomography angiography (CTA) images following endovascular aneurysm repair (EVAR) is not satisfactory, since artifacts resulting from metallic implants obstruct the clear depiction of stent and isolation lumens, and also adjacent soft tissues. However, current techniques to reduce these artifacts still need further advancements due to higher radiation doses, longer processing times and so on. Thus, the aim of this study is to assess the impact of utilizing Single-Energy Metal Artifact Reduction (SEMAR) alongside a novel deep learning image reconstruction technique, known as the Advanced Intelligent Clear-IQ Engine (AiCE), on image quality of CTA follow-ups conducted after EVAR.

MATERIALS

This retrospective study included 47 patients (mean age ± standard deviation: 68.6 ± 7.8 years; 37 males) who underwent CTA examinations following EVAR. Images were reconstructed using four different methods: hybrid iterative reconstruction (HIR), AiCE, the combination of HIR and SEMAR (HIR + SEMAR), and the combination of AiCE and SEMAR (AiCE + SEMAR). Two radiologists, blinded to the reconstruction techniques, independently evaluated the images. Quantitative assessments included measurements of image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the longest length of artifacts (AL), and artifact index (AI). These parameters were subsequently compared across different reconstruction methods.

RESULTS

The subjective results indicated that AiCE + SEMAR performed the best in terms of image quality. The mean image noise intensity was significantly lower in the AiCE + SEMAR group (25.35 ± 6.51 HU) than in the HIR (47.77 ± 8.76 HU), AiCE (42.93 ± 10.61 HU), and HIR + SEMAR (30.34 ± 4.87 HU) groups (p < 0.001). Additionally, AiCE + SEMAR exhibited the highest SNRs and CNRs, as well as the lowest AIs and ALs. Importantly, endoleaks and thrombi were most clearly visualized using AiCE + SEMAR.

CONCLUSIONS

In comparison to other reconstruction methods, the combination of AiCE + SEMAR demonstrates superior image quality, thereby enhancing the detection capabilities and diagnostic confidence of potential complications such as early minor endleaks and thrombi following EVAR. This improvement in image quality could lead to more accurate diagnoses and better patient outcomes.

Dynamic Radial MR Imaging for Endoleak Surveillance after Endovascular Repair of Abdominal Aortic Aneurysms with Inconclusive CT Angiography: A Prospective Study

Background/Objectives: To assess free-breathing, dynamic radial magnetic resonance angiography (MRA) for detecting endoleaks post-endovascular aortic repair (EVAR) in cases with inconclusive computed tomography angiography (CTA). Methods: This prospective single-center study included 17 participants (mean age, 70 ± 9 years; 13 males) who underwent dynamic radial MRI (Golden-angle RAdial Sparse Parallel-Volumetric Interpolated BrEath-hold, GRASP-VIBE) after inconclusive multiphasic CT for the presence of endoleaks during the follow-up of EVAR-treated abdominal aortic aneurysms. CT and MRI datasets were independently assessed by two radiologists for image quality, diagnostic confidence, and the presence/type of endoleak. Statistical analyses included interrater and intermethod agreement, and diagnostic performance (sensitivity, specificity, area under the curve (AUC)). Results: Subjective image analysis demonstrated good image quality and interrater agreement (k ≥ 0.6) for both modalities, while diagnostic confidence was significantly higher in MRA (p = 0.03). There was significantly improved accuracy for detecting type II endoleaks on MRA (AUC 0.97 [95% CI: 0.87, 1.0]) compared to CTA (AUC 0.66 [95% CI: 0.41, 0.91]; p = 0.03). Although MRA demonstrated higher values for sensitivity, specificity, AUC, and interrater agreement, none of the other types nor the overall detection rate for endoleaks showed differences in the diagnostic performance over CT (p ≥ 0.12). CTA and MRA revealed slight to moderate intermethod concordance in endoleak detection (k = 0.3-0.64). Conclusions: The GRASP-VIBE MRA characterized by high spatial and temporal resolution demonstrates clinical feasibility with good image quality and superior diagnostic confidence. It notably enhances diagnostic performance in detecting and classifying endoleaks, particularly type II, compared to traditional multiphase CTA with inconclusive findings.

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.

BMI-Adapted Double Low-Dose Dual-Source Aortic CT for Endoleak Detection after Endovascular Repair: A Prospective Intra-Individual Diagnostic Accuracy Study

PURPOSE

To assess the diagnostic accuracy of BMI-adapted, low-radiation and low-iodine dose, dual-source aortic CT for endoleak detection in non-obese and obese patients following endovascular aortic repair.

METHODS

In this prospective single-center study, patients referred for follow-up CT after endovascular repair with a history of at least one standard triphasic (native, arterial and delayed phase) routine CT protocol were enrolled. Patients were divided into two groups and allocated to a BMI-adapted (group A, BMI < 30 kg/m2; group B, BMI ≥ 30 kg/m2) double low-dose CT (DLCT) protocol comprising single-energy arterial and dual-energy delayed phase series with virtual non-contrast (VNC) reconstructions. An in-patient comparison of the DLCT and routine CT protocol as reference standard was performed regarding differences in diagnostic accuracy, radiation dose, and image quality.

RESULTS

Seventy-five patients were included in the study (mean age 73 ± 8 years, 63 (84%) male). Endoleaks were diagnosed in 20 (26.7%) patients, 11 of 53 (20.8%) in group A and 9 of 22 (40.9%) in group B. Two radiologists achieved an overall diagnostic accuracy of 98.7% and 97.3% for endoleak detection, with 100% in group A and 95.5% and 90.9% in group B. All examinations were diagnostic. The DLCT protocol reduced the effective dose from 10.0 ± 3.6 mSv to 6.1 ± 1.5 mSv (p < 0.001) and the total iodine dose from 31.5 g to 14.5 g in group A and to 17.4 g in group B.

CONCLUSION

Optimized double low-dose dual-source aortic CT with VNC, arterial and delayed phase images demonstrated high diagnostic accuracy for endoleak detection and significant radiation and iodine dose reductions in both obese and non-obese patients compared to the reference standard of triple phase, standard radiation and iodine dose aortic CT.

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.

New microvascular ultrasound techniques: abdominal applications

Microvascular ultrasound (MVUS) is a new ultrasound technique that allows the detection of slow-velocity flow, providing the visualization of the blood flow in small vessels without the need of intravenous contrast agent administration. This technology has been integrated in the most recent ultrasound equipment and applied for the assessment of vascularization. Compared to conventional color Doppler and power Doppler imaging, MVUS provides higher capability to detect intralesional flow. A growing number of studies explored the potential applications in hepatobiliary, genitourinary, and vascular pathologies. Different flow patterns can be observed in hepatic and renal focal lesions providing information on tumor vascularity and improving the differential diagnosis. This article aims to provide a detailed review on the current evidences and applications of MVUS in abdominal imaging.

Safe Follow-Up after Endovascular Aortic Repair with Unenhanced MRI: The SAFEVAR Study

We aimed to investigate whether unenhanced magnetic resonance imaging (MRI) could represent a safe and highly sensitive tool for endoleak screening in patients treated with endovascular aneurysm repair (EVAR) using computed tomography angiography (CTA) as a reference standard. Patients who underwent CTA for EVAR follow-up at our institution were prospectively enrolled. All MRI examinations were performed with a 1.5 T unit. The true-FISP and HASTE sequences of the MRI scans were assessed for the presence of hyperintensity within the aneurysm sac outside the graft, whereas phase-contrast through-plane sequences were used for blood flow quantification. We included 45 patients, 5 (11%) of whom were female. The median age was 73 years (IQR 68−78 years). Among our patients, 19 (42%) were positive for endoleaks at CTA, of whom 13 (68%) had type II endoleaks and 6 (32%) had type I endoleaks. There were no significant differences in age, sex, aneurysm type, prosthesis type, or contrast-to-noise ratio between hyperintensity and thrombus between patients with and without endoleaks (p > 0.300). The combined evaluation of true-FISP and HASTE yielded 100% sensitivity (95% CI: 79−100%) and 19% specificity (95% CI: 7−40%). Patients with a positive CTA had a median thrombus flow of 0.06 L/min (IQR 0.03−0.23 L/min), significantly greater than that of patients with a negative CTA (p = 0.007). Setting a threshold at 0.01 L/min, our MRI protocol yielded 100% sensitivity, 56% specificity, and an AUC of 0.76 (95% CI 0.60−0.91). In conclusion, unenhanced MRI has perfect sensitivity for endoleak detection, although with subpar specificity that could be improved with phase-contrast flow analysis.

Survival, reintervention and surveillance reports: long-term, centre-level evaluation and feedback of vascular interventions

The combination of registry and administrative claims data have facilitated research and quality improvement efforts. Using Vascular Quality Initiative (VQI) registry data and Medicare claims we have generated centre-specific survival, reintervention and surveillance reports which benchmark participating centres' performance to the VQI as a whole and to published guidelines. In 2021, we distributed these reports to 303 participating centres. These reports offer an opportunity for centres to evaluate their performance and identify focus areas for quality improvement work.

Chronic Thoracic Aortic Dissection: How to Treat, When to Intervene

Thoracic aortic dissection (AD) is associated with increased morbidity and mortality. Acute aortic syndrome is the first presentation of the disease in most cases. While acute AD management follows concrete guidelines because of its urgent and life-threatening nature, chronic AD is usually overlooked, although it concerns a wide spectrum of patients surviving an acute event. Acute AD survivors ultimately enter a chronic aortic disease course. Patients with chronic thoracic AD (CTAD) require lifelong surveillance and a proportion of them may present with symptoms and late complications demanding further surgical or endovascular treatment. However, the available data concerning the management of CTAD is sparse in the literature. The management of patients with CTAD is challenging as far as determining the best medical therapy and deciding on intervention are concerned. Until recently, there were no guidelines or recommendations for imaging surveillance in patients with chronic AD. The diagnostic methods for imaging aortic diseases have been improved, while the data on new endovascular and surgical approaches has increased significantly. In this review, we summarize the current evidence in the diagnosis and management of CTAD and the latest recommendations for the surgical/endovascular aortic repair of CTAD.

Single centre experience with Excluder® stent graft; 17-year outcome

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) has become a mainstay of abdominal aorta aneurysm treatment. Long term follow-up on specific stent grafts is needed.

PATIENTS AND METHODS

This study included 123 patients (104 men; mean age 73.0 years, range 51-89) with abdominal aorta aneurysm, treated with Excluder^® stent graft between October 2002 and June 2008. Periprocedural and follow-up data were retrieved by reviewing the records of our institution, while time and cause of death were retrieved from the National Institute of Public Health. If an abdominal aortic aneurysm rupture was listed as the cause of death, records were retrieved from the institution that issued the death certificate. Our primary goal was to assess the primary technical success rate, type 1 and type 2 endoleak, reintervention free survival, 30-day mortality, the overall survival and aneurysm rupture-free survival.

RESULTS

The median follow-up was 9.7 years (interquartile range, 4.6-13.8). The primary technical success was 98.4% and the 30-day mortality accounted for 0.8%. Secondary procedures were performed in 29 (23.6%) patients during the follow-up period. The one-, five-, ten-, fifteen- and seventeen-year overall survival accounted for 94.3%, 74.0%, 47.2%, 35.8% and 35.8%, while the aneurysm-related survival was 98.4%, 96.3%, 92.6%, 92.6%, 92.6%. In seven (5.7%) patients, abdominal aortic rupture was found as the primary cause of death during follow-up.

CONCLUSIONS

Our data showed that EVAR with Excluder^® stent graft offers good long-term results. More than 75% of patients can be treated completely percutaneously. Late ruptures do occur in the first ten years, raising awareness about regular medical controls.

Any Postoperative Surveillance Improves Survival after Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Endovascular aortic repair (EVAR) has advanced the care of patients with ruptured abdominal aortic aneurysms (rAAA) with improved early postoperative morbidity and mortality. However, this comes at the cost of a rigorous postoperative surveillance schedule to monitor for further aneurysmal degeneration. Adherence to surveillance recommendations is known to be poor in the elective setting, but has yet to be studied in the ruptured population. The aim of this study is to investigate predictors of incomplete surveillance after EVAR for rAAA (rEVAR) and examine how adherence impacts outcomes.

METHODS

This was a retrospective case control study of patients undergoing rEVAR at a multiple hospital single healthcare center (2003-2020). Patients were excluded if they underwent open conversion during their index hospitalization or died within 60 days of surgery. Follow-up was broadly categorized as complete surveillance (60-day postoperative visit and annually thereafter) or incomplete surveillance, comprising both patients with less than recommended surveillance (minimal surveillance) and completely lost to follow-up (LTF). Any follow-up was defined as patients with complete or minimal surveillance. We investigated predictors of complete versus incomplete surveillance by multivariate logistic regression. Secondary outcomes included overall survival and cumulative incidence of reintervention controlling for the competing risk of mortality, generating hazard ratios (HR) and subdistribution hazard ratios (SHR).

RESULTS

One-hundred and sixty patients (mean age 74 ± 10.1 years, 81.2% male) out of 673 total rAAA met study inclusion criteria. Complete surveillance was seen in 41.3% of our cohort, with the remainder with minimal surveillance (29.4%) or LTF (29.4%). Incomplete surveillance was associated with male sex (odds ratio [OR] 2.56; 95% CI 1.02-6.43), lack of a primary care provider (PCP; OR 0.20; 95% CI 0.04-0.99), and longer driving distance from home to treating hospital (OR 2.37; 95% CI 1.08-5.20). Survival was not different between complete and incomplete surveillance groups, however any follow-up conferred improved survival over LTF (HR 0.57; 95% CI 0.331-0.997; P = 0.049). Reintervention was associated with incomplete surveillance (SHR 0.29; 95% CI 0.11-0.75), and discharge to a facility (SHR 0.25; 95% CI 0.067-0.94).

CONCLUSIONS

Incomplete surveillance was observed in over 50% of patients who underwent rEVAR and was associated with male sex, lack of PCP, and longer driving distance. Any follow-up conferred a survival benefit, yet incomplete surveillance was associated with a lower risk of reintervention. Targeted strategies to prevent LTF, and less stringent, personalized follow-up plans that may confer similar survival benefit with better patient adherence should be investigated.

Virtual Non-Contrast Reconstructions of Photon-Counting Detector CT Angiography Datasets as Substitutes for True Non-Contrast Acquisitions in Patients after EVAR-Performance of a Novel Calcium-Preserving Reconstruction Algorithm

The purpose of this study was to evaluate virtual-non contrast reconstructions of Photon-Counting Detector (PCD) CT-angiography datasets using a novel calcium-preserving algorithm (VNCPC) vs. the standard algorithm (VNCConv) for their potential to replace unenhanced acquisitions (TNC) in patients after endovascular aneurysm repair (EVAR). 20 EVAR patients who had undergone CTA (unenhanced and arterial phase) on a novel PCD-CT were included. VNCConv- and VNCPC-series were derived from CTA-datasets and intraluminal signal and noise compared. Three readers evaluated image quality, contrast removal, and removal of calcifications/stent parts and assessed all VNC-series for their suitability to replace TNC-series. Image noise was higher in VNC- than in TNC-series (18.6 ± 5.3 HU, 16.7 ± 7.1 HU, and 14.9 ± 7.1 HU for VNCConv-, VNCPC-, and TNC-series, p = 0.006). Subjective image quality was substantially higher in VNCPC- than VNCConv-series (4.2 ± 0.9 vs. 2.5 ± 0.6; p < 0.001). Aortic contrast removal was complete in all VNC-series. Unlike in VNCConv-reconstructions, only minuscule parts of stents or calcifications were erroneously subtracted in VNCPC-reconstructions. Readers considered 95% of VNCPC-series fully or mostly suited to replace TNC-series; for VNCConv-reconstructions, however, only 75% were considered mostly (and none fully) suited for TNC-replacement. VNCPC-reconstructions of PCD-CT-angiography datasets have excellent image quality with complete contrast removal and only minimal erroneous subtractions of stent parts/calcifications. They could replace TNC-series in almost all cases.

Abdominal Aortic and Visceral Artery Aneurysms

Abdominal aortic aneurysms account for nearly 9000 deaths annually, with ruptured abdominal aortic aneurysms being the thirteenth leading cause of death in the United States. Abdominal aortic aneurysms can be detected by screening, but a majority are detected incidentally. Visceral artery aneurysms are often discovered incidentally, and treatment is guided by symptoms, etiology, and size. A timely diagnosis and referral to a vascular specialist are essential for timely open or endovascular repair and to ensure successful patient outcomes.

Type II Endoleak Nidus Volume on Arterial and Delayed Phases of Initial CT Angiography after Endovascular Abdominal Aortic Aneurysm Repair Predicts Persistent Endoleak and Aneurysm Sac Enlargement

Purpose

To evaluate type II endoleak nidus volume (ENV) in the arterial phase (ENV_AP) and delayed phase (ENV_DP) of the first postoperative CT angiography (CTA) as a predictor of persistent endoleak and aneurysm sac enlargement at follow-up CTA in patients with endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm.

Materials and Methods

Ninety-three patients (mean age ± standard deviation, 72 years ± 8; range, 56-88 years) with EVAR and type II endoleak were included in a single-institution retrospective study conducted between March 1, 2005, and December 31, 2018. ENV_AP, ENV_DP, change of volume (ENV_DP-AP), and percentage of ENV_AP and ENV_DP in aneurysm sac volume (ASV) (ENV_AP/ASV%, ENV_DP/ASV%, respectively) were measured on first postoperative CTA images. The mean follow-up was 31.6 months ± 26.6 (range, 6-163.8 months). Patients were divided into two groups (group A, spontaneous resolution of endoleak without intervention [n = 29] and group B, persistent endoleak at follow-up CTA [n = 64]) and compared by using the Mann-Whitney U, Wilcoxon signed rank, and Pearson χ² tests. Receiver operating characteristic (ROC) analysis was used to compare accuracies of parameters at first postoperative CTA.

Results

The accuracy of ENV_DP (area under the ROC curve [AUC], 0.78) was superior to the accuracy of ENV_DP/ASV% (AUC, 0.76), ENV_DP-AP (AUC, 0.74), ENV_AP (AUC, 0.71), and ENV_AP/ASV% (AUC, 0.69) in indicating persistent endoleak. In group B, 46 patients (72%) showed ASV enlargement and 44 patients (69%) underwent endoleak embolization. ENV_AP (1.7 cm³ ± 2.9 vs 3.4 cm³ ± 4.2; P = .001), ENV_DP (2.9 cm³ ± 3.8 vs 8.0 cm³ ± 9.6; P < .001), ENV_DP-AP (1.1 cm³ ± 1.8 vs 4.5 cm³ ± 7.8; P < .001), ENV_AP/ASV% (0.9% ± 1.5 vs 1.7% ± 2.2; P = .003), and ENV_DP/ASV% (1.6% ± 2.2 vs 3.7% ± 3.6; P < .001) were smaller in group A than in group B.

Conclusion

ENV_DP of the first postoperative CTA is an accurate predictor of persistent endoleak compared with ENV_AP, and persistent endoleak is associated with aneurysm sac enlargement, in which earlier intervention is recommended.© RSNA, 2021.

Intravascular Ultrasound-Assisted Endovascular Exclusion of Penetrating Aortic Ulcers

BACKGROUND

Penetrating aortic ulcer (PAU) is an atherosclerotic lesion penetrating the elastic lamina and extending into the media of the aorta. It may evolve into intramural hematoma, focal dissection, pseudoaneurysm, and eventually rupture. The purpose of this study was to evaluate the effectiveness of a totally intravascular ultrasound (IVUS)-assisted endovascular exclusion of PAU.

METHODS

Thirteen consecutive patients (median age 66 years) underwent IVUS-assisted endovascular exclusion of PAU. The primary end points were fluoroscopy time, radiation dose, and occurrence of type I primary endoleak. Secondary end points were postoperative mortality and morbidity, arterial access complications, postoperative length of stay in the hospital, and occurrence of type II endoleaks.

RESULTS

The median fluoroscopy time was 4 min (4-5). The median radiation dose was 4.2 mGy (3.9-4.5). A proximal and distal landing zone of at least 2 cm could be obtained in all the patients. No patient presented a type I endoleak. No postoperative mortality, no morbidity, or arterial access complication was observed. The median length of postoperative stay in the hospital was 2 days (2-3). The median length of follow-up was 25 months (9.2-38.7). One late type II endoleak was observed (7.7%), because of reflux from the intercostal arteries, without the need for additional treatment.

CONCLUSIONS

IVUS-assisted endovascular treatment of PAU allows durable exclusion of PAU with a short fluoroscopy time and no need for injection of contrast media. Further series are needed to confirm the results of this preliminary study.