Abdominal aortic aneurysms volume growth patterns with three-dimensional ultrasound.

BACKGROUND: Three-dimensional ultrasound (3D-US) and computed tomography (CT) have proven abdominal aortic aneurysm (AAA) volume a more sensitive measure of growth than diameter. This proof-of-concept study aimed to investigate the clinical applicability of two-dimensional ultrasound and 3D-US for AAA diameter and volume growth pattern evaluation. METHODS: AAA patients with at least three follow-ups within a minimum of 24 months were included prospectively and consecutively from the COpenhagen Aneurysms CoHort (COACH). Individual diameter and volume growth rates were categorized as rapid, slow, or no growth (>6.0, 3.8-6.0, and ≤3.7 mm/year for diameter. >17.4, 8.8-17.3, and ≤8.7 mL/year for volume). Similarly, diameter and volume growth patterns were categorized as as linear, exponential, staccato, and indeterminate growth, based from individual regressions. RESULTS: Thirty patients were included, of which 19 (63%) had no diameter growth, 10 (33%) had slow growth, and one (3%) had rapid growth. Regarding volume, 11 (37%) patients had no growth, 12 (40%) had slow growth, and seven (23%) had rapid growth. Growth patterns according to diameter showed that 18 (60%) patients had linear growth, none had staccato or exponential growth. Twelve (40%) were indeterminate. Volume growth patterns found 19 (63%) patients with linear growth, 3 (10%) with staccato, and none with exponential growth. Eight (27%) were indeterminate. CONCLUSIONS: Analysis of AAA volume growth patterns is a practical and safe modality that seems more sensitive at detecting growth patterns than AAA diameter. Volume also detects more AAA growth than diameter.

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.

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.

Three- and Two-Dimensional Ultrasound is as Accurate as Computed Tomography in Aortic Sac Assessment after Endovascular Aortic Repair.

BACKGROUND: To compare aortic sac changes after endovascular aneurysm repair (EVAR) assessed by three-dimensional ultrasound (3D-US), two-dimensional ultrasound (2D-US), and traditional computed tomographic angiography (CTA). METHODS: Using volume assessment with three-dimensional CTA (3D-CTA-volume) as the gold standard, this study investigated aortic sac changes at three and 12 months after EVAR with three different ultrasound methods (2D-US anterior-posterior (AP) diameter, 3D-US AP centerline diameter, and 3D-US partial volume), and traditional CT multiplanar outer-to-outer diameter (CT-MPR OTO diameter). From august 1st, 2011 to January 2014, consecutive EVAR patients (n = 113) were available for analysis in two time intervals; 1) between preoperative and three-month follow-up and 2) between three and 12 month follow-up. RESULTS: The risk of missing true aortic sac growth (false negative finding) at three-month postoperative visit using 3D-US partial volume, 3D-US AP centerline diameter, 2D-US AP diameter, and CT-MPR OTO diameter was 19%, 21%, 22%, and 18%, respectively. Corresponding low sensitivities (0% to 21%) and kappa-values (<0.50) in detecting aortic sac changes were found. The risk of missing true growth between three and 12 months were lower (6%, 5%, 6%, and 6%, respectively), and matching sensitivities 33%, 33%, 17%, and 17%, respectively. CONCLUSIONS: All tested methods for aortic sac changes were as good as traditional CT-MPR OTO diameter and corresponded poorly with 3D-CTA-volume at three months postoperative visit but substantially better after 12 months where the residual sac change was more profound.

Clinical validation of three-dimensional ultrasound for abdominal aortic aneurysm.

OBJECTIVE: Three-dimensional ultrasound (3D-US) examination is a relatively new modality that can be used for abdominal aortic aneurysm (AAA) surveillance, and may offer improved reproducibility over conventional two-dimensional ultrasound (2D-US) examination. The aim of this study was to evaluate the interoperator reproducibility of maximum anterior-to-posterior diameter by nonphysician ultrasound technicians in a typical vascular laboratory setting, on patients with infrarenal AAAs using 3D-US and 2D-US examination. METHODS: A total of 134 consecutive patients with asymptomatic infrarenal AAAs were screened. Of the 134 patients, 28 (21%) were screen failures. From the remaining 106 patients, 3 (2.8%) had missing data and 13 (12.3%) had technically unacceptable image quality. As a result, 90 patients were included for final analysis. Ultrasound image acquisitions were performed during the single visit. The 2D-US images were evaluated at the time of examination by the respective ultrasound technicians who acquired them. All 3D-US images were evaluated offline by both ultrasound technicians after a wash-out period of at least 6 weeks. RESULTS: Excellent interoperator reproducibility was observed for measuring maximum diameter using 3D-US (intraclass correlation coefficient, 0.97), and good agreement among ultrasound technicians (mean difference, -0.08 mm; limits of agreement, -3.17; 3.00 mm). When using 3D-US examination, 74 of the 90 patients (82%) were estimated within 2 mm of interoperator variability. Of 90 patients, 52 (58%) were estimated to be within the same variability by 2D-US examination. Estimating AAA diameter using 3D-US was superior to 2D-US with respect to interoperator reproducibility. CONCLUSIONS: Both 3D-US and 2D-US examination demonstrated good reproducibility among two vascular ultrasound technicians with superior agreement from 3D-US examination. The present results support the broader use of 3D-US in standard AAA surveillance programs.

Contrast Enhanced Three Dimensional Ultrasound for Intraluminal Thrombus Assessment in Abdominal Aortic Aneurysms.

OBJECTIVES: The impact of intraluminal thrombus (ILT) on abdominal aortic aneurysm (AAA) progression can be investigated non-invasively by three dimensional contrast enhanced ultrasound (3D-CEUS). The aim was to validate 3D-CEUS ILT volume and thickness measurements against computed tomography angiography (CTA), and to determine inter- and intra-operator reproducibility. METHODS: The design was for a planned comparison of 3D-CEUS and CTA and of repeated 3D-CEUS measurements in a blinded set up. Consecutive patients with asymptomatic AAA (n = 137, maximum diameter 30-55 mm) from a single centre were consecutively assessed by CTA and 3D-CEUS in a blinded setup. After exclusion of failed CTA (n = 2) and inconclusive 3D-CEUS (n = 8), 127 3D-CEUS/CTA pairs were analysed by Bland-Altman plots. 3D-CEUS inter- and intra-operator reproducibility were determined in a subgroup (n = 30) measured twice by two blinded investigators. RESULTS: In 24 of 127 (19%) patients, no ILT was found on 3D-CEUS. Intraluminal thrombus absence was confirmed by 3D-CTA analysis in all but two cases. Mean ILT volume difference between 3D-CEUS and CTA was 2.2 mL (5% of mean volume) and range of variability (ROV) amounted to ± 10.2 mL. Mean ILT thickness difference was 0.6 mm with a ROV of ± 4.6 mm 3D-CEUS inter-operator variations of ILT volume and thickness measurements were low (ROV ± 8.8 mL and ±2.9 mm, respectively). The corresponding intra-operator ROVs were ±7.5 mL and ±3.3 mm, respectively. CONCLUSIONS: 3D-CEUS demonstrated good reproducibility and a good agreement with CTA when estimating ILT volume and maximum thickness in AAA patients. It is a promising research tool to investigate potential interactions between ILT, AAA growth, and rupture.

von Willebrand Factor and Prekallikrein in Plasma Are Associated With Thrombus Volume in Abdominal Aortic Aneurysms.

OBJECTIVES: Disruption of the endothelial lining may be one of the events linking intraluminal thrombus and abdominal aortic aneurysm growth. In the present study, we examined whether von Willebrand factor activity in plasma, contact proteins of blood coagulation, and inflammatory biomarkers may be associated with intraluminal thrombus volume in search of a biochemical marker of endothelial damage and thrombus size. DESIGN: Prospective study, correlating potential endothelial biomarkers and intraluminal thrombus volume acquired by computed tomography angiography. MATERIALS AND METHODS: Plasma was consecutively obtained from 38 patients with asymptomatic infrarenal abdominal aortic aneurysm. von Willebrand factor activity, thrombin generation time, factor XII, and prekallikrein concentration were measured in plasma on automated and in-house platforms. In total, 8 patients were excluded due to ongoing anticoagulant therapy, renal impairment, or nonappearance, thus leaving 30 patients for further analysis. All patients had computed tomography angiography, and intraluminal volume was quantified off-line by OsiriX 6.5. RESULTS: Median intraluminal thrombus volume was 42.7 mL. Spearman correlation analysis revealed a positive correlation between thrombus volume, von Willebrand factor activity (ρ = 0.56, P = .0013), and prekallikrein concentration in plasma (ρ = 0.54, P = .002). CONCLUSION: von Willebrand factor activity and concentration of prekallikrein may both be of importance regarding the evolution of thrombus in abdominal aortic aneurysm and possible biomarkers for aneurysm growth.

[Median arcuate ligament syndrome]. / Truncus coeliacus-kompressionssyndrom.

The median arcuate ligament syndrome is a rare entity and poorly described in Danish literature. The syndrome is a diagnosis of exclusion and is characterized by chronic abdominal pain, postprandial pain and weight loss. It is believed that the median arcuate ligament, being a fibrous structure of diaphragm, compresses the coeliac trunk thus causing stenosis and malperfusion of the gastrointestinal organs. Until recently, there has been some reluctance to consider intervention with revascularization or ligament release. Within the latest decade minimally invasive techniques, including laparoscopic release of the median arcuate ligament, have shown promising results.

[Pseudoaneurysm in the subclavian artery as a long-term complication to clavicula fracture].

Post-traumatic pseudoaneurysm in the subclavian artery is a rare complication to clavicula fracture, but it seldom requires intervention, and therefore screening for pseudoaneurysms is not recommended after a relevant trauma. This case report confirms that a pseudoaneurysm can develop slowly and can manifest even several years after the primary trauma. A 79-year-old patient presented herself with a 20 × 20 cm large pulsating tumour on the left side of her neck, and a pseudoaneurysm on the subclavian artery had been diagnosed as a late complication to a clavicula fracture nine years before. This case was rare because of the late-onset aneurysm, manifesting itself by the large size and neurological symptoms. The patient was treated with stent grafting without further surgical intervention, resulting in relief from neurological symptoms and a decreasing size of the pseudoaneurysm. Antithrombotic treatment after the endovascular procedure was not recommended.