One-year volume growth of abdominal aortic aneurysms measured by extended field-of-view ultrasound.

BACKGROUND: Measurement of volume has the potential to detect subtle growth not recognized in the current surveillance paradigm of abdominal aortic aneurysms (AAAs). Currently available three-dimensional ultrasound allows for estimation of AAA volume, but for most patients, the AAA extends beyond the ultrasound field-of-view and only allows visualization of a partial AAA volume. A new extended field-of-view three-dimensional ultrasound protocol (XFoV US) has been found to improve the proportion of patients with visualization of the full AAA volume. METHODS: To investigate the applicability of the XFoV US protocol in estimating AAA volume growth in follow-up, 86 patients with AAAs were recruited from the surveillance program at a university hospital. All were imaged by XFoV US at baseline and at one-year follow-up. RESULTS: Assessment of full volume, based on visualization of the AAA neck and bifurcation at both baseline and one-year follow-up, was achieved in 67/86 (78%) of patients. One-year mean growth in maximum diameter was 2.8 mm (6%/year), in centerline length 2.9 mm (4%/year), and in volume 15.9 mL (19%/year). In 17/67 (25%) of patients, volume growth was detected in diameter-stable AAAs. Baseline XFoV US volume was associated with one-year AAA volume growth, while, conversely, maximum baseline diameter was not associated with one-year AAA diameter growth. CONCLUSIONS: This study concludes that the XFoV US protocol provides a safe and repeatable modality for assessing AAA volume growth, and that AAA volume is a promising predictive measure of AAA growth.

Endoleak following endovascular repair of popliteal artery aneurysm: clinical outcome and contrast-enhanced ultrasound detection.

BACKGROUND: Continued blood flow in the aneurysm sac after repair, also known as endoleak, can occur after both open and endovascular popliteal aneurysm repair (EPAR) with risk for aneurysm sac enlargement. Primary aims were to investigate aneurysm sac growth and the presence and classification of endoleak after EPAR using contrast-enhanced ultrasound (CEUS). METHODS: Cross-sectional study of patients receiving EPAR with expanded polytetrafluorethylene (ePTFE) covered stent-grafts between 1st of January 2009 and 1st of February 2019 at a tertiary referral endovascular center. Patients were re-invited in 2021 and 31 legs were examined for endoleak using CEUS. Endoleaks were classified by a core-lab consisting of three CEUS-experienced physicians. RESULTS: Median follow-up was 57 months (range 33-143 months). Endoleak was detected in 16 PAA, and categorized as type I (N.=3), type II (N.=10), type III (N.=1) or indeterminate (N.=2). Median maximal PAA diameter was 24 mm (range 15-55 mm) at the time of EPAR compared to 17 mm (range 6-43 mm) at follow-up (P<.001). Maximal aneurysm sac diameter was smaller at follow-up than at the index procedure in both PAAs with and without endoleak on CEUS (P=0.005 vs. P<0.001, respectively). There was no difference in PAA sac shrinkage at follow-up between patients with or without endoleak (P=0.28). Freedom from aneurysm sac growth was 97%. CONCLUSIONS: CEUS was sensitive in endoleak detection after EPAR. Shrinkage of the PAA sac was found in both patients with and without endoleaks. CEUS appears useful for targeted examinations rather than routine surveillance after EPAR.

Anticoagulants and reduced thrombus load in abdominal aortic aneurysms assessed with three-dimensional contrast-enhanced ultrasound examination.

OBJECTIVE: The relationship between intraluminal thrombus (ILT) and abdominal aortic aneurysm (AAA) growth and rupture risk remains ambiguous. Studies have shown a limited effect of antiplatelet therapy on ILT size, whereas the impact of anticoagulant therapy on ILT is unresolved. This study aims to evaluate an association between antithrombotic therapy and ILT size assessed with three-dimensional contrast-enhanced ultrasound (3D-CEUS) examination in a cohort of patients with AAA. METHODS: In a cross-sectional study, 309 patients with small AAAs were examined with 3D-CEUS. Patients were divided into three groups based on prescribed antithrombotic therapy: anticoagulant (n = 36), antiplatelet (n = 222), and no antithrombotic therapy (n = 51). Patient ILT size was calculated in volume and thickness and compared between the three groups. RESULTS: Patients on anticoagulants had a significantly lower estimated marginal mean ILT volume of 16 mL (standard error [SE], ±3.2) compared with 28 mL (SE, ±2.7) in the no antithrombotic group and 30 mL (SE, ±1.3) in the antiplatelet group when adjusting for AAA volume (P < .001) and comorbidities (P < .001). In addition, patients on anticoagulant therapy had significantly lower estimated marginal mean ILT thickness of 10 mm (SE, ±1.1) compared with 13 mm (SE, ±0.9) in the no antithrombotic group of and 13mm (SE, ±0.4) in the antiplatelet group when adjusting for AAA diameter (P = .03) and comorbidities (P = .035). CONCLUSIONS: A 3D-CEUS examination is applicable for ILT assessment and demonstrates that patients with AAA on anticoagulant therapy have lower ILT thickness and volume than patients with AAA on antiplatelet therapy and those without antithrombotic therapy. Causality between anticoagulants and ILT size, and extrapolation to AAA growth and rupture risk, is unknown and merits further investigations, to further nuance US-based AAA surveillance strategy.

Full-Volume Assessment of Abdominal Aortic Aneurysms by 3-D Ultrasound and Magnetic Tracking.

Volume assessment of abdominal aortic aneurysms (AAAs) using 3-D ultrasound (US) is an innovative technique reporting good agreement with computed tomography angiography. One major limitation of the current 3-D US technique is a limited field of view, allowing full AAA acquisition in only 60% of patients. This study presents two new US acquisition protocols using magnetic field tracking, providing an "extended field of view" (XFoV-2-D and XFoV-3-D) with the aim of including both the aortic bifurcation and neck for full-volume assessment, and compares these methods with the current standard 3-D US protocol and with computed tomography angiography. A total of 20 AAA patients were included and underwent the current standard 3-D US protocol and the two novel 3-D US "extended field of view" protocols. Four patients were excluded from further analysis because of low image quality, leaving 16 patients eligible for analysis. Full AAA volume was achieved in 8 patients (50%) using the standard 3-D US protocol, in 11 patients (69%) with the XFoV-2-D protocol and in 13 patients (81%) with the XFoV-3-D protocol. In conclusion, this article describes two new and feasible US protocols applicable for full-AAA-volume estimation in most patients and should initiate further research into the added value of full volume in AAA surveillance.

The Effects of Naturalistic Light on Diurnal Plasma Melatonin and Serum Cortisol Levels in Stroke Patients during Admission for Rehabilitation: A Randomized Controlled Trial.

Background: Stroke patients admitted for rehabilitation often lack sufficient daytime blue light exposure due to the absence of natural light and are often exposed to light at unnatural time points. We hypothesized that artificial light imitating daylight, termed naturalistic light, would stabilize the circadian rhythm of plasma melatonin and serum cortisol levels among long-term hospitalized stroke patients. Methods: A quasi-randomized controlled trial. Stroke patients in need of rehabilitation were randomized between May 1, 2014, and June 1, 2015 to either a rehabilitation unit equipped entirely with always on naturalistic lighting (IU), or to a rehabilitation unit with standard indoor lighting (CU). At both inclusion and discharge after a hospital stay of at least 2 weeks, plasma melatonin and serum cortisol levels were measured every 4 hours over a 24-hour period. Circadian rhythm was estimated using cosinor analysis, and variance between time-points. Results: A total of 43 were able to participate in the blood collection. Normal diurnal rhythm of melatonin was disrupted at both inclusion and discharge. In the IU group, melatonin plasma levels were increased at discharge compared to inclusion (n = 23; median diff, 2.9; IQR: -1.0 to 9.9, p = 0.030) and rhythmicity evolved (n = 23; p = 0.007). In the CU group, melatonin plasma levels were similar between discharge and inclusion and no rhythmicity evolved. Overall, both patient groups showed normal cortisol diurnal rhythms at both inclusion and discharge. Conclusions: This study is the first to demonstrate elevated melatonin plasma levels and evolved rhythmicity due to stimulation with naturalistic light.