Biomechanical studies on type B aortic dissection

The first part (Chapter 2) of this dissertation gives an introduction to Type B Aortic Dissection (TBAD). This overview shows several prognostic predictors of dissection related events (dissection related death or need for intervention) after initial medical management in acute uncomplicated TBAD. Predictors of complications in acute uTBAD during admission are aortic diameter ≥40mm, a primary entry tear >10mm, primary entry tear located on the concavity (undersurface) of the distal aortic arch, a FL diameter > 22mm, a peak CRP level >96mg/L and patency of the false lumen (defined as the concurrent presence of both flow and thrombus). The blood flow in the false lumen is highly variable due to morphological differences between various types of dissections. It is conceivable that patent branch vessels originating from the false lumen in an aortic dissection type B may contribute to persistent blood flow and patent false lumen, and thus to prognosis. Therefore, an in-vitro study was performed with a surgically constructed false lumen and an adjustable outflow branch (Chapter 3.). This in-vitro study show that different outflow from branch vessels originating from the false lumen in TBAD result in expansion of cross-sectional false lumen area. This might have important consequences for patients with uTBAD when patent branch vessel(s) originating from the false lumen and partial thrombosis (occluding distal tears) or no distal tear are present, as these patients might be more at risk for developing complicated TBAD. Haemodynamics, dissection morphology and aortic wall elasticity have a major influence onthe pressure in the false lumen. The influence of haemodynamics and dissection morphology have been investigated often in multiple in-vitro and ex-vivo studies in contrast to aortic wall elasticity.In Chapter 4 the influence of aortic wall elasticity on the diameter and pressure of the false lumen in aortic dissection is studied in-vitro. It shows that aortic wall elasticity is an important parameter altering the false lumen. This in-vitro study showed that an aortic wall with reduced elasticity results in an increased false lumen diameter in the mid and distal part of the false lumen. False lumen expansion might result in higher stress of the aortic wall and at the ending of the dissection. More insight in the hemodynamic changes during cardiac cycle in the true and false lumen of uncomplicated TBAD might result in prediction of adverse outcomes. Four-Dimensional flow Magnetic Resonance Imaging (4D flow MRI) compared to CTA provides insight into hemodynamic dimensions such as Wall Shear Stress. In arterial blood flow, the WSS expresses the viscous force per unit area applied by the fluid on the wall in a direction at the local interface. In Chapter 5. our ex-vivo research illustrates that an increase in heart rate (HR) from 60 to 80 bpm resultedin a significantly increase of the False Lumen Volume (FLV) and Wall Shear Stress (WSS) of the false lumen. Hereby we confirm that strict HR control is of major importance and reduces the mean and peak WSS in uncomplicated TBAD. The first line therapy in TBAD with malperfusion syndrome is coverage of the proximalentry tear by Thoracic Endo-Vascular Aortic Repair (TEVAR). When this method is unfeasible, endovascular aortic fenestration has been proposed as an alternative technique. Fenestration is a minimally invasive alternative for the treatment of acute symptomatic aortic dissections because it may quickly decrease the pressure gradient of the false lumen. It remains unclear where the optimal location of these fenestrations should be chosen. In Chapter 6. the false lumen volume after different fenestration strategies was studied. This in-vitro study showed that distal fenestration of the false lumen in aortic dissection will result in the largest false lumen reduction.LUMC / Geneeskund

The Influence of Aortic Wall Elasticity on the False Lumen in Aortic Dissection: An In Vitro Study

Cardiovascular Aspects of Radiolog

Determinants of Acute Kidney Injury and Renal Function Decline After Endovascular Abdominal Aortic Aneurysm Repair

Orthopaedics, Trauma Surgery and Rehabilitatio

Stent graft sizing for endovascular abdominal aneurysm repair using open source image processing software

Introduction: An important step to reach a favorable outcome of abdominal endovascular aneurysm repair (EVAR) is preoperative sizing of the stent graft using computed tomography angiography (CTA) images of the abdominal aorta. A variety of costly image processing software options is available to obtain the necessary aortic measurements. A package that can be used for EVAR sizing is OsiriX Lite (R)-an open source, freely downloadable image processing option. This study assesses the concurrent validity of OsiriX Lite (R) when compared with commercially available 3Mensio Vascular (R) and Siemens Syngo.via (R).Methods: CTA scans of 20 patients that underwent EVAR for abdominal aneurysm were selected, 10 elective and 10 ruptured. For each scan, 6 observers determined 20 parameters needed for proper stent graft sizing, 2 using Osirix Lite (R), 3 using 3Mensio Vascular (R), and 1 using Siemens Syngo.via (R). For each parameter, an intraclass correlation coefficient (ICC) and a P-value were calculated. Interrater agreement was interpreted using the Koo and Li Guidelines. Time needed to perform EVAR planning was compared.Results: Overall interrater agreement between the 3 sizing options was found to be either "good" or "moderate" for 16 out of 20 parameters (80%). Time needed to perform EVAR planning was not significantly different for Osirix Lite (R) (568 sec) when compared with 3Mensio Vascular (R) (603 sec) or Siemens Syngo.via (R) (659 sec) with a P-value of 0.88.Conclusions: The authors conclude that Osirix Lite (R) is an accurate and time-effective image processing option for preoperative sizing of an EVAR stent graft when matched to 3Mensio Vascular (R) and Siemens Syngo.via (R).Development and application of statistical models for medical scientific researc

Saccular Aneurysm of the Brachiocephalic Vein

Vascular Surger

The Role of Branch Vessels in Aortic Type B Dissection: An in vitro Study

Cardiovascular Aspects of Radiolog

Infection of endovascular abdominal aortic aneurysm stent graft after urosepsis: case report and review of the literature

Vascular Surger

A Pseudoaneurysm of the Deep Palmar Arch After Penetrating Trauma to the Hand: Successful Exclusion by Ultrasound Guided Percutaneous Thrombin Injection

: Introduction: Pseudoaneurysm of the hand is a rare condition; most are treated surgically. Ultrasound guided thrombin injection has not previously been reported as a treatment option for pseudoaneurysms of the deep palmar arch. Report: A man was referred to the emergency department with a swollen, painful hand after penetrating trauma. On physical examination, a pulsating tumor was found on the dorsum of the hand. Imaging revealed a pseudoaneurysm vascularized by the deep palmar arch. Ultrasound guided percutaneous thrombin injection was successfully performed. Conclusion: Thrombin injection might be a safe alternative option in the treatment of pseudoaneurysm of the deep palmar arch. Keywords: Deep palmar arch, Pseudoaneurysm, Thrombin injectio

Wall Shear Stress Assessment of the False Lumen in Acute Type B Aortic Dissection Visualized by 4-Dimensional Flow Magnetic Resonance Imaging: An Ex-Vivo Study

Background:Four-dimensional flow magnetic resonance imaging (4D flow MRI) can accurately visualize and quantify flow and provide hemodynamic information such as wall shear stress (WSS). This imaging technique can be used to obtain more insight in the hemodynamic changes during cardiac cycle in the true and false lumen of uncomplicated acute Type B Aortic Dissection (TBAD). Gaining more insight of these forces in the false lumen in uncomplicated TBAD during optimal medical treatment, might result in prediction of adverse outcomes.Methods:A porcine aorta dissection model with an artificial dissection was positioned in a validated ex-vivo circulatory system with physiological pulsatile flow. 4D flow MR images with 3 set heartrates (HR; 60 bpm, 80 bpm and 100 bpm) were acquired. False lumen volume per cycle (FLV), mean and peak systolic WSS were determined from 4D flow MRI data. For validation, the experiment was repeated with a second porcine aorta dissection model.Results:During both experiments an increase in FLV (initial experiment: Delta FLV = 2.05 ml, p < 0.001, repeated experiment: Delta FLV = 1.08 ml, p = 0.005) and peak WSS (initial experiment: Delta WSS = 1.2 Pa, p = 0.004, repeated experiment: Delta WSS = 1.79 Pa, p = 0.016) was observed when HR increased from 60 to 80 bpm. Raising the HR from 80 to 100 bpm, no significant increase in FLV (p = 0.073, p = 0.139) was seen during both experiments. The false lumen mean WSS increased significant during initial (2.71 to 3.85 Pa; p = 0.013) and non-significant during repeated experiment (3.22 to 4.00 Pa; p = 0.320).Conclusion:4D flow MRI provides insight into hemodynamic dimensions including WSS. Our ex-vivo experiments showed that an increase in HR from 60 to 80 bpm resulted in a significant increase of FLV and WSS of the false lumen. We suggest that strict heart rate control is of major importance to reduce the mean and peak WSS in uncomplicated acute TBAD. Because of the limitations of an ex-vivo study, 4D flow MRI will have to be performed in clinical setting to determine whether this imaging model would be of value to predict the course of uncomplicated TBAD.Cardiovascular Aspects of Radiolog

Nationwide study of the treatment of mycotic abdominal aortic aneurysms comparing open and endovascular repair in The Netherlands

Contains fulltext : 226470.pdf (Publisher’s version ) (Closed access)OBJECTIVE: Mycotic aneurysms of the abdominal aorta (MAAA) can be treated by open repair (OR) or endovascular aneurysm repair (EVAR). This nationwide study provides an overview of the situation of MAAA treatment in The Netherlands in 2016. METHODS: A retrospective cohort study was conducted with all centers that registered aortic abdominal aneurysms in the Dutch Surgical Aneurysm Audit in 2016. Questionnaires on 1-year outcomes were sent to all centers that treated patients with MAAA. The primary aim was to determine 30-day and 1-year mortality and morbidity of OR- and EVAR-treated patients. Morbidity was determined by the need for reoperations and the number of readmissions to the hospital. RESULTS: Twenty-six MAAA were detected in the Dutch Surgical Aneurysm Audit database of 2016, resulting in an incidence of 0.7% of all registered abdominal aortic aneurysms. The 30-day mortality for OR and EVAR treated patients was 1 in 13 and 0 in 13, respectively. Major and minor reinterventions within 30 days were needed for two (one OR and one EVAR) and two (one OR and one EVAR) patients, respectively. Two patients (15.4%) in the OR group and one patient (7.7%) in the EVAR group were readmitted to hospital within 30 days. In total, 1-year outcomes of 23 patients were available. In the OR group, one patient (9.1%) died in the first postoperative year. There was one major reintervention (removal of endoprosthesis and spiralvein reconstruction) in the EVAR group. Two patients (18.2%) treated with OR and two (16.7%) treated with EVAR required a minor reintervention. In both groups, four patients (OR, 36.4%; EVAR, 33.3%) were readmitted to hospital within 1 year postoperatively. CONCLUSIONS: Both OR- and EVAR-treated patients show acceptable clinical outcomes after 30 days and at the 1-year follow-up. Depending on the clinical course of the patient, EVAR may be considered in the management of this disease