Editor's Choice - Influence of Proximal Aortic Neck Diameter on Durability of Aneurysm Sealing and Overall Survival in Patients Undergoing Endovascular Aneurysm Repair. Real World Data from the Gore Global Registry for Endovascular Aortic Treatment (GREAT).

OBJECTIVES: Aortic neck diameter is an independent anatomical feature that is poorly understood, yet potentially linked to proximal seal failure and adverse outcome following standard EVAR. The aim of this study was to assess whether large proximal aortic neck (LAN) diameter is associated with adverse outcome using prospectively collected individual patient data from The Global Registry for Endovascular Aortic Treatment (GREAT). METHODS: A total of 3166 consecutive patients, from 78 global centres, receiving Gore Excluder stent grafts for infrarenal abdominal aortic aneurysm repair between 2011 and 2017 were included. Patient demographics, biometrics, operative details, and clinical outcome were analysed. Patients were divided into two groups: normal baseline proximal aortic neck (NAN) diameter (<25 mm on computed tomography aortography), and LAN (≥25 mm). Clinical follow up (including imaging) was available for 76.5% of patients 5 years post-intervention. Primary endpoints analysed were Type IA endoleak and any aortic re-intervention up to 5 years post-procedure. A composite endpoint of Type IA endoleak, re-intervention, aortic rupture, or aortic related mortality was also assessed. RESULTS: A total of 1977 (62.4%) patients were classified NAN and 1189 (37.6%) were LAN. Immediate technical success was achieved in 3164 out of 3166 (>99.9%) of cases. Freedom from Type IA endoleak was achieved in 99.3% at 1 year and 97.3% at 5 years (lower in LAN vs. NAN: 96.8% [CI 93.7-98.4] vs. 98.6% [CI 94.5-99.6], p = .007). Freedom from aortic re-intervention was 93.7% at 1 year and 83.2% at 5 years (78.6% [CI 66.0-87.0] LAN vs. 86.0% [CI 81.8-89.3] NAN, p = .11). Freedom from primary composite endpoint was 95.9% at 1 year and 84.9% at 5 years (81.3% [CI 69.2-89.0] LAN vs. 87.0% [CI 81.6-91.0] NAN, p = .066). Five year survival was lower in the LAN group; 64.6% (CI 50.1-75.7) vs. 76.5% (CI 70.7-81.3), p = .03). CONCLUSION: LAN is associated with delayed Type IA endoleak occurrence and lower overall survival.

Evaluating quantitative approaches to dynamic susceptibility contrast MRI among carotid endarterectomy patients.

PURPOSE: To evaluate two dynamic susceptibility contrast (DSC) quantification methods in symptomatic carotid artery disease patients undergoing carotid endarterectomy (CEA) surgery by comparing methods directly and assessing the reliability of each method in the hemisphere contralateral to surgery. MATERIALS AND METHODS: Absolute cerebral blood flow (CBF) and volume (CBV) was calculated in putamen and sensorimotor gray matter of 17 patients using two methods: 1) The Bookend method that scales relative DSC images to CBV values calculated from the ratio of pre- and postcontrast T1-weighted images, and 2) the Tail-scaling method that uses the ratio of area under the tails of the venous and arterial concentration time-courses to scale the DSC images. RESULTS: There was a positive correlation between the methods with significant correlation post-CEA (P < 0.035). Intersession correlation was greater when using the Tail-scaling method contralateral to surgery (P < 0.004). CONCLUSION: We have demonstrated correlation between methods that is significant after surgery and have found that the Tail-scaling method produces better test-retest reliability than our implementation of the Bookend method. Results from this study suggest that DSC has the potential to measure hemodynamic changes after endarterectomy and future work is required to establish clinical value.

Intracranial hemodynamics is altered by carotid artery disease and after endarterectomy: a dynamic magnetic resonance angiography study.

BACKGROUND AND PURPOSE: Carotid endarterectomy (CEA) has become a routine procedure to treat symptomatic carotid artery disease and reduce the risk of recurrent cerebral ischemic events. The purpose of this study was to use an arterial spin labeling dynamic magnetic resonance angiography technique to characterize intracranial hemodynamics before and after CEA. METHODS: Thirty-seven carotid artery disease patients participated in this study, of whom 24 underwent magnetic resonance imaging before and after CEA. Seventeen control subjects spanning 5 decades underwent magnetic resonance imaging to assess age-related changes. Hemodynamic metrics (that is, relative time to peak and amplitude) were calculated with a γ-variate model. Linear regression was used to relate carotid artery disease burden to downstream hemodynamics in the circle of Willis. RESULTS: Relative time to peak increased with age in controls (P<0.020). For patients, relative time to peak was positively correlated with percent stenosis (P<0.050), independent of age. At 1 day after CEA, the middle cerebral artery ipsilateral to the CEA showed significant dynamic magnetic resonance angiography changes: relative time to peak decreased (P<0.017) and the flow amplitude increased (P<0.009). No pre- versus post-CEA changes were significant in the contralateral middle cerebral artery or posterior segments. CONCLUSIONS: This noninvasive, arterial spin labeling-based method produced time-resolved images that were used to characterize intracranial arterial flow associated with aging, extracranial carotid artery disease, and CEA. Results demonstrate that the technique has the sensitivity to detect hemodynamic changes after CEA.

Knee dislocation and vascular injury: 4 year experience at a UK Major Trauma Centre and vascular hub.

INTRODUCTION: Knee dislocation is a rare but potentially devastating injury. Quoted rates of associated vascular compromise vary dramatically between 3.3% and 64%, and the best approach to investigate and diagnose such an injury remains controversial. We aim to evaluate our own 4-year experience of knee dislocation and vascular injury as a UK Major Trauma Centre and vascular hub. METHODS: Knee dislocation was defined as disruption of at least two major stabilising ligaments of the knee and gross instability requiring an operation. Patients were identified from the Department of Trauma and Orthopaedics patient database across a 4 year period from 2010 to 2014. Electronic patient records, imaging and hard notes were retrieved and reviewed retrospectively and relevant information recorded. RESULTS: Twenty-five cases of knee dislocation were identified. Male to female ratio was 11.5:1 with a mean age of 33 years (range 17-71). One patient had a vascular injury which ultimately required a femoro-popliteal bypass graft. Twenty-four patients had documented examination findings pertaining to the vascular status of the limb. Seventeen patients had specific reference to the presence or absence of pedal pulses. The remaining seven cases were documented as either "warm well perfused" or "neurovascularly in-tact". Nine patients were discharged directly from the emergency department with outpatient follow up. All admitted cases had documented vascular examination findings the following day. Two patients had additional adjunctive non-invasive investigations. No patients were examined with duplex ultrasound, although two patients had pulses confirmed with hand-held doppler ultrasound. Three patients had an angiogram. Four cases have a documented discussion with or review from a vascular surgeon. DISCUSSION AND CONCLUSIONS: Our rates of vascular injury are in line with the most recent and largest study to date. Non-invasive investigation and selective angiography has been safe in identifying significant vascular compromise, however, there is inconsistency in management pathways, and too much reassurance attributed to the presence of pedal pulses on initial examination. Safety and consistency could be improved with the introduction of a formalised evidence-based protocol for the initial evaluation of knee dislocation and vascular injury.

Chimney-Graft as a Bail-Out Procedure for Endovascular Treatment of an Inflammatory Juxtarenal Abdominal Aortic Aneurysm.

Inflammatory and juxtarenal Abdominal Aortic Aneurysm (j-iAAA) represents a technical challenge for open repair (OR) due to the peculiar anatomy, extensive perianeurysmal fibrosis, and dense adhesion to the surrounding tissues. A 68-year-old man with an 11 cm asymptomatic j-iAAA was successfully treated with elective EVAR and chimney-graft (ch-EVAR) without postprocedural complications. Target vessel patency and normal renal function are present at 24-month follow-up. The treatment of j-iAAA can be technically challenging. ch-EVAR is a feasible and safe bail-out method for elective j-iAAA with challenging anatomy.

Efficacy and Safety of Augmenting the Preclose Technique with a Collagen-Based Closure Device for Percutaneous Endovascular Aneurysm Repair.

PURPOSE: To report our experience of selectively augmenting the preclose technique for percutaneous endovascular aneurysm repair (p-EVAR) with an Angio-Seal device as a haemostatic adjunct in cases of significant bleeding after tensioning the sutures of the suture-mediated closure devices. MATERIALS AND METHODS: Prospectively collected data for p-EVAR patients at our institute were analysed. Outcomes included technical success and access site complications. A logistic regression model was used to analyse the effects of sheath size, CFA features and stent graft type on primary failure of the preclose technique necessitating augmentation and also on the development of complications. RESULTS: p-EVAR was attempted via 122 CFA access sites with a median sheath size of 18-French (range 12- to 28-French). Primary success of the preclose technique was 75.4% (92/122). Angio-Seal augmentation was utilised as an adjunct to the preclose technique in 20.5% (25/122). The overall p-EVAR success rate was 95.1% (116/122). There was a statistically significant relationship (p = 0.0093) between depth of CFA and primary failure of preclose technique. CFA diameter, calcification, type of stent graft and sheath size did not have significant effects on primary preclose technique failure. Overall 4.9% (6/122) required surgical conversion but otherwise there were no major complications. CONCLUSION: Augmentation with an Angio-Seal device is a safe and effective adjunct to increase the success rate of the preclose technique in p-EVAR.

Assessing the quality and reproducibility of a proteomic platform for clinical stroke biomarker discovery.

The aim of this study was to investigate the quality and reproducibility of mass spectra derived from a matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) platform in a patient population undergoing carotid endarterectomy. Plasma samples were either digested with trypsin or left undigested, fractionated with either C18 or weak cation exchange (WCX) columns and analysed by MALDI-TOF MS. Quality of mass spectra for each method was assessed by baseline correction (lower area under the curve ratio indicating higher quality) and signal-to-noise ratio. Mean coefficient of variation (CV%) assessed reproducibility between repeated experiments and methods. Identified mass peak intensity differences were assessed for consistency across repeated experiments. Plasma from six patients was analysed. The quality of mass spectra was significantly better when derived from digested plasma fractionated by either WCX or C18 methods compared to undigested plasma fractionated by WCX (analysis of variance, p < 0.05). Mean CV% for repeated experiments was 18% and 28% for WCX and C18 fractionated digested plasma, respectively. A small number of differences in mass peak intensities were consistently observed in repeated experiments. Repeated experiments are required to confidently identify non-random mass peak intensity differences as putative plasma biomarkers that merit further investigation.

Absolute arterial cerebral blood volume quantification using inflow vascular-space-occupancy with dynamic subtraction magnetic resonance imaging.

In patients with steno-occlusive disease of the internal carotid artery (ICA), cerebral blood flow may be maintained by autoregulatory increases in arterial cerebral blood volume (aCBV). Therefore, characterizing aCBV may be useful for understanding hemodynamic compensation strategies. A new 'inflow vascular-space-occupancy with dynamic subtraction (iVASO-DS)' MRI approach is presented where aCBV (mL blood/100 mL parenchyma) is quantified without contrast agents using the difference between images with and without inflowing blood water signal. The iVASO-DS contrast mechanism is investigated (3.0 T, spatial resolution=2.4 x 2.4 x 5 mm(3)) in healthy volunteers (n=8; age=29+/-5 years), and patients with mild (n=7; age=72+/-8 years) and severe (n=10; age=73+/-8 years) ICA stenoses. aCBV was quantified in right and left hemispheres in controls, and, alongside industry standard dynamic susceptibility contrast (DSC), contralateral (cont), and ipsilateral (ips) to maximum stenosis in patients. iVASO contrast significantly correlated (R=0.67, P<0.01) with DSC-CBV after accounting for transit time discrepancies. Gray matter aCBV (mL/100 mL) was 1.60+/-0.10 (right) versus 1.61+/-0.20 (left) in controls, 1.59+/-0.38 (cont) and 1.65+/-0.37 (ips) in mild stenosis patients, and 1.72+/-0.18 (cont) and 1.58+/-0.20 (ips) in severe stenosis patients. aCBV was asymmetric (P<0.01) in 41% of patients whereas no asymmetry was found in any control. The potential of iVASO-DS for autoregulation studies is discussed in the context of existing hemodynamic literature.