The Presence of a High Peak Feature Within Low-Average Shear Stimuli Induces Quiescence in Venous Endothelial Cells.

Wall shear stress (WSS) is an important stimulus in vascular remodelling and vascular lesion development. The current methods to assess and predict the risk associated with specific unsteady WSS consider the WSS mean values or the presence of reverse phases described by the oscillatory shear index. Recent evidence has shown that the accuracy of these methods is limited, especially with respect to the venous environment. Unsteady WSS are characterised by several features that may individually affect endothelial cells. Consequently, we assessed the effects of averaged WSS (TAWSS), temporal WSS gradient (TWSSG), maximum WSS (WSS peak) and reverse phase (OSI) by applying different WSS profiles to venous EC in-vitro, using a real-time controlled cone-and-plate cell-shearing device for 24 h. We found that TWSSG and WSS peak affect cell elongation and alignment respectively. We also found that the WSS waveforms with a peak of 1.5 Pa or higher significantly correlate with the induction of a protective phenotype. Cell phenotype induced by these high peak waveforms does not correlate to what is predicted by the hemodynamic indices currently used. The definition of reliable hemodynamic indices can be used to inform the computational models aimed at estimating the hemodynamic effects on vascular remodelling.

On the effect of computed tomography resolution to distinguish between abdominal aortic aneurysm wall tissue and calcification: A proof of concept.

PURPOSE: The purpose of this study is to determine the optimal target CT spatial resolution for accurately imaging abdominal aortic aneurysm (AAA) wall characteristics, distinguishing between tissue and calcification components, for an accurate assessment of rupture risk. MATERIALS AND METHODS: Ruptured and non-ruptured AAA-wall samples were acquired from eight patients undergoing open surgical aneurysm repair upon institutional review board approval and informed consent was obtained from all patients. Physical measurements of AAA-wall cross-section were made using scanning electron microscopy. Samples were scanned using high resolution micro-CT scanning. A resolution range of 15.5-155µm was used to quantify the influence of decreasing resolution on wall area measurements, in terms of tissue and calcification. A statistical comparison between the reference resolution (15.5µm) and multi-detector CT resolution (744µm) was also made. RESULTS: Electron microscopy examination of ruptured AAAs revealed extremely thin outer tissue structure <200µm in radial distribution which is supporting the aneurysm wall along with large areas of adjacent medial calcifications far greater in area than the tissue layer. The spatial resolution of 155µm is a significant predictor of the reference AAA-wall tissue and calcification area measurements (r=0.850; p<0.001; r=0.999; p<0.001 respectively). The tissue and calcification area at 155µm is correct within 8.8%±1.86 and 26.13%±9.40 respectively with sensitivity of 87.17% when compared to the reference. CONCLUSION: The inclusion of AAA-wall measurements, through the use of high resolution-CT will elucidate the variations in AAA-wall tissue and calcification distributions across the wall which may help to leverage an improved assessment of AAA rupture risk.

Calcification Volume Reduces Stretch Capability and Predisposes Plaque to Rupture in an in vitro Model of Carotid Artery Stenting.

OBJECTIVE/BACKGROUND: Carotid artery stenting (CAS) in calcified arteries carries a higher peri-operative risk. This study investigates the relationship between the stretching limits of carotid plaque samples and calcification in order to determine a stretch tolerance criterion for endovascular intervention. METHODS: Seventeen carotid plaque samples were acquired from standard endarterectomy procedures. The maximum stretch capability of the global plaque was determined by circumferentially extending the tissue to complete failure. Quantitative assessment of calcification was performed using high resolution computed tomography, including measures of percent calcification volume fraction (%CVF) and calcification configuration. Maximum stretch properties were then related to calcification measures in order to evaluate the predictive power of calcification for determining plaque stretching limits. RESULTS: A strong negative correlation was found between %CVF and stretch ratio with respect to specific calcification configuration types. All plaques with < 70% stenosis superseded the minimum required stretch threshold. Severe stenosis (> 70%) warrants a stretch of at least 2.33 during revascularisation and only plaques containing concentric calcifications with < 20% CVF successfully reached this minimum required stretch threshold. CONCLUSION: The addition of calcification measures to the stenosis classification may help in guiding endovascular intervention techniques to achieve a balance between an acceptable residual patency level while avoiding plaque rupture in calcified carotid plaques.

Towards the characterisation of carotid plaque tissue toughness: Linking mechanical properties to plaque composition.

UNLABELLED: The morphological manifestation of calcification within an atherosclerotic plaque is diverse and the response to cutting balloon angioplasty remains an elusive target to predict in the presence of extensive calcification. This study examines the resistance of plaque tissue to blade penetration by characterising the underlying toughness properties and stratifying the upper and lower scale toughness limits based on the strong mechanical influence of calcification. Mechanical toughness properties of the common, bifurcation and internal carotid artery (n=62) were determined using guillotine-cutting tests measuring the energy required to pass a surgical blade through a unit length of plaque tissue. The corresponding structural composition of the dissected plaque segments was characterised using Fourier transform infrared analysis, electron microscopy and energy dispersive x-ray spectroscopy. Mechanical results reveal a clear distinction in toughness properties within each region of the carotid vessel with significantly tougher properties localised in the bifurcation (p=0.004) and internal region (p=0.0003) compared to the common. The severity of the intra-plaque variance is highest in plaques with high toughness localised in the bifurcation region (p<0.05). Structural examination reveals that the diverse mechanical influence of the level of calcification present is characteristic of specific regions within the carotid plaque. The energy required to overcome the calcific resistance and propagate a controlled cut in the calcified tissue at each region varies further with the degree of plaque progression. The identification of the localised calcification characteristics is a key determinant in achieving successful dissection of the severely toughened plaque segments during cutting balloon angioplasty. STATEMENT OF SIGNIFICANCE: Calcification plays a fundamental role in plaque tissue mechanics and demonstrates a diverse range of material moduli properties. This work addresses the characterisation of the toughness properties in human carotid plaque tissue using a fracture mechanics approach. Toughness determines the energy required to propagate a controlled cut in the plaque material. This parameter is crucial for predicting the cutting forces required during endovascular cutting balloon angioplasty intervention. Results demonstrate that a strong relationship exists between the structural calcification configurations, fracture mechanisms and associated toughness properties that are characteristic of specific regions within the carotid artery plaque. The identification of the morphological characteristics of localised calcification may serve as a valuable quantitative measure for cutting balloon angioplasty treatment.

Comparing the endothelialisation of extracellular matrix bioscaffolds with coated synthetic vascular graft materials.

INTRODUCTION: Existing synthetic vascular grafts have unacceptably high failure rates when replacing below knee arteries. In vitro endothelialisation is a technique, which has been shown to enhance the patency rates of below knee vascular grafts. Synthetic materials are however poor cellular substrates and must be combined with coatings to promote cellular growth and attachment. The most common coating clinically is fibrin-coated ePTFE. The aim of our study was to compare the endothelialisation of fibrin-coated ePTFE with novel extracellular matrix (ECM) biomaterials that we hypothesise will provide a superior substrate for cell growth. METHODS: Human endothelial cells were cultured on ECM scaffolds and fibrin-coated ePTFE. Uncoated Dacron and ePTFE acted as controls. The cells were examined for viability, phenotype, adhesion and proliferation. Cell morphology was accessed using scanning electron microscopy. RESULTS: Cells remained viable and produced von Willebrand factor on all substrates tested. ECM scaffolds and fibrin-modified ePTFE achieved statistically higher attachment efficiency when compared to both uncoated synthetic graft materials (p ≤ 0.001). At 90 min 80 ± 3.6% of cells had attached to the ECM scaffold compared to Dacron (30 ± 4.5%, n = 3) and ePTFE (33 ± 2.5%, n = 3). There was no difference in adhesion rates between ECM scaffolds and fibrin-coated ePTFE (p = 1.00). Endothelial cells proliferated fastest on ECM scaffolds when compared to all other materials tested (p < 0.001) and reached confluency on day seven. CONCLUSION: ECM bioscaffolds offer an improved substrate for promoting rapid endothelialisation compared to fibrin-coated ePTFE by combining firm cellular anchorage and superior cell expansion.

The influence of composition and location on the toughness of human atherosclerotic femoral plaque tissue.

The toughness of femoral atherosclerotic tissue is of pivotal importance to understanding the mechanism of luminal expansion during cutting balloon angioplasty (CBA) in the peripheral vessels. Furthermore, the ability to relate this parameter to plaque composition, pathological inclusions and location within the femoral vessels would allow for the improvement of existing CBA technology and for the stratification of patient treatment based on the predicted fracture response of the plaque tissue to CBA. Such information may lead to a reduction in clinically observed complications, an improvement in trial results and an increased adoption of the CBA technique to reduce vessel trauma and further endovascular treatment uptake. This study characterises the toughness of atherosclerotic plaque extracted from the femoral arteries of ten patients using a lubricated guillotine cutting test to determine the critical energy release rate. This information is related to the location that the plaque section was removed from within the femoral vessels and the composition of the plaque tissue, determined using Fourier Transform InfraRed spectroscopy, to establish the influence of location and composition on the toughness of the plaque tissue. Scanning electron microscopy (SEM) is employed to examine the fracture surfaces of the sections to determine the contribution of tissue morphology to toughness. Toughness results exhibit large inter and intra patient and location variance with values ranging far above and below the toughness of healthy porcine arterial tissue (Range: 1330-3035 for location and 140-4560J/m(2) for patients). No significant difference in mean toughness is observed between patients or location. However, the composition parameter representing the calcified tissue content of the plaque correlates significantly with sample toughness (r=0.949, p<0.001). SEM reveals the presence of large calcified regions in the toughest sections that are absent from the least tough sections. Regression analysis highlights the potential of employing the calcified tissue content of the plaque as a preoperative tool for predicting the fracture response of a target lesion to CBA (R(2)=0.885, p<0.001). STATEMENT OF SIGNIFICANCE: This study addresses a gap in current knowledge regarding the influence of plaque location, composition and morphology on the toughness of human femoral plaque tissue. Such information is of great importance to the continued improvement of endovascular treatments, particularly cutting balloon angioplasty (CBA), which require experimentally derived data as a framework for assessing clinical cases and advancing medical devices. This study identifies that femoral plaque tissue exhibits large inter and intra patient and location variance regarding tissue toughness. Increasing calcified plaque content is demonstrated to correlate significantly with increasing toughness. This highlights the potential for predicting target lesion toughness which may lead to an increased adoption of the CBA technique and also further the uptake of endovascular treatment.

On the effect of calcification volume and configuration on the mechanical behaviour of carotid plaque tissue.

Vascular calcification is a complex molecular process that exhibits a number of relatively characteristic morphology patterns in atherosclerotic plaques. Treatment of arterial stenosis by endovascular intervention, involving forceful circumferential expansion of the plaque, can be unpredictable in calcified lesions. The aim of this study was to determine the mechanical stretching mechanisms and define the mechanical limits for circumferentially expanding carotid plaque lesions under the influence of distinct calcification patterns. Mechanical and structural characterisation was performed on 17 human carotid plaques acquired from patients undergoing endarterectomy procedures. The mechanical properties were determined using uniaxial extension tests that stretch the lesions to complete failure along their circumferential axis. Calcification morphology of mechanically ruptured plaque lesions was characterised using high resolution micro computed tomography imaging. Scanning electron microscopy was used to examine the mechanically induced failure sites and to identify the interface boundary conditions between calcified and non-calcified tissue. The mechanical tests produced four distinct trends in mechanical behaviour which corresponded to the calcification patterns that structurally defined each mechanical group. Each calcification pattern produced unique mechanical restraining effects on the plaque tissue stretching properties evidenced by the variation in degree of stretch to failure. Resistance to failure appears to rely on interactions between calcification and non-calcified tissue. Scanning electron microscopy examination revealed structural gradations at interface boundary conditions to facilitate the transfer of stress. This study emphasises the mechanical influence of distinct calcification configurations on plaque expansion properties and highlights the importance of pre-operative lesion characterisation to optimise treatment outcomes.

A MultiCenter Pilot Randomized Controlled Trial of Remote Ischemic Preconditioning in Major Vascular Surgery.

A pilot randomized controlled trial that evaluated the effect of remote ischemic preconditioning (RIPC) on clinical outcomes following major vascular surgery was performed. Eligible patients were those scheduled to undergo open abdominal aortic aneurysm repair, endovascular aortic aneurysm repair, carotid endarterectomy, and lower limb revascularization procedures. Patients were randomized to RIPC or to control groups. The primary outcome was a composite clinical end point comprising any of cardiovascular death, myocardial infarction, new-onset arrhythmia, cardiac arrest, congestive cardiac failure, cerebrovascular accident, renal failure requiring renal replacement therapy, mesenteric ischemia, and urgent cardiac revascularization. Secondary outcomes were components of the primary outcome and myocardial injury as assessed by serum troponin values. The primary outcome occurred in 19 (19.2%) of 99 controls and 14 (14.1%) of 99 RIPC group patients (P = .446). There were no significant differences in secondary outcomes. Our trial generated data that will guide future trials. Further trials are urgently needed.

Successful Treatment of Acute on Chronic Mesenteric Ischaemia by Common Iliac to Inferior Mesenteric Artery Bypass.

Chronic mesenteric ischaemia is a rare and potentially fatal condition most commonly due to atherosclerotic stenosis or occlusion of two or more mesenteric arteries. Multivessel revascularisation of both primary mesenteric vessels, the celiac artery and superior mesenteric artery (SMA), is the current mainstay of treatment; however, in a certain cohort of patients, revascularisation one or both vessels may not be possible. Arteries may be technically unreconstructable or the patient may be surgically unfit for the prolonged aortic cross clamping times required. Here we present a case involving a 72-year-old woman with acute on chronic mesenteric ischaemia. She was a high risk surgical patient with severe unreconstructable stenotic disease of the SMA and celiac arteries. She was successfully treated with single vessel revascularisation of the inferior mesenteric artery (IMA) via a common iliac to IMA reversed vein bypass. At two-year follow-up, the graft remains patent and the patient continues to be symptom-free and is maintaining her weight.

The role of venous diameter in predicting arteriovenous fistula maturation: when not to expect an AVF to mature according to pre-operative vein diameter measurements? A best evidence topic.

This best evidence topic was investigated according to a described protocol. We asked the question: what is the minimal vein diameter that can successfully predict maturation of an arteriovenous fistula (AVF) in patients undergoing dialysis. Using the reported search 804 papers were found, of which five represented the best evidence to answer the clinical question. All studies assessed the association between successful AVF maturation and the size of vein used. The strongest evidence came from a nonrandomised controlled follow-up study in which 76% of fistulas created using >2 mm cephalic vein successfully matured compared to 16% when the vein measured ≤2 mm. Another prospective, multicentre study showed 65% successful maturation using veins >4 mm compared to 45% with veins <3 mm. Vein diameter was found to be an independent predictor of maturation in multivariate regression analysis in two retrospective observational studies. Another retrospective observational study found that using venous measurements of ≥2.5 mm following tourniquet application resulted in more fistulas been created that would have otherwise been denied based on venous ultrasound mapping. A large multicentre randomised clinical trial assessing the use of different vein sizes both with and without tourniquet application using proper statistical tools - such as receiver operating characteristic - is required to make a final recommendation. Until then, a vein diameter of <2.5 mm should be considered inadequate for formation of an AVF, particularly if those measurements remain unchanged following the use of tourniquet.

Mechanical, biological and structural characterization of human atherosclerotic femoral plaque tissue.

The failure of endovascular treatments of peripheral arterial disease represents a critical clinical issue. Specialized data are required to tailor such procedures to account for the mechanical response of the diseased femoral arterial tissue to medical device deployment. The purpose of this study is to characterize the mechanical response of atherosclerotic femoral arterial tissue to large deformation, the conditions typical of angioplasty and stenting, and also to determine the mechanically induced failure properties and to relate this behaviour to biological content and structural composition using uniaxial testing, Fourier transform infrared spectroscopy and scanning electron microscopy. Mechanical and biological characterization of 20 plaque samples obtained from femoral endarterectomy identified three distinct classifications. "Lightly calcified" samples display linear mechanical responses and fail at relatively high stretch. "Moderately calcified" samples undergo an increase in stiffness and ultimate strength coupled with a decrease in ductility. Structural characterization reveals calcified nodules within this group that may be acting to reinforce the tissue matrix, thus increasing the stiffness and ultimate strength. "Heavily calcified" samples account for the majority of samples tested and exhibit significantly reduced ultimate strength and ductility compared to the preceding groups. Structural characterization of this group reveals large areas of calcified tissue dominating the failure cross-sections of the samples. The frequency and structural dominance of these features solely within this group offers an explanation as to the reduced ultimate strength and ductility and highlights the need for modern peripheral endovascular devices to account for this behaviour during novel medical device design.

Assessing the quality of online information for patients with carotid disease.

INTRODUCTION: Controversy exists relating to carotid endarterectomy (CEA) versus carotid artery stenting (CAS). We aimed to assess the quality of online patient information relating to both. METHODS: The Google search engine was searched for "carotid endarterectomy" and "carotid stenting". The first 50 webpages returned were assessed. The Gunning Fog Index (GFI) and Flesch Reading Ease Score (FRES) were calculated to assess readability. The LIDA tool (Minervation Ltd., Oxford, U.K.) was used to assess accessibility, usability and reliability. RESULTS: 20% (n = 10) of the webpages returned for CEA were from peer reviewed sources with 34% (n = 17) posted by hospitals or health services. Comparatively, for CAS, 40% (n = 20) were peer reviewed with 16% (n = 8) posted by hospitals or health services. GFI and FRES scores indicated webpages for both CEA and CAS had poor general readability. Webpages for CEA were easier to read than those for CAS (mean FRES difference of 6.7 (95% CI 0.51 to 12.93, p = 0.03). Median LIDA scores demonstrated acceptable reliability, accessibility and usability of information for both CEA and CAS webpages. The more readable webpages were not associated with higher LIDA scores for either CEA or CAS webpages. CONCLUSION: Webpages providing information on carotid disease management must be made more readable. Online information currently available to patients regarding CAS is more difficult to read and comprehend than CEA.

Mechanical, biological and structural characterization of in vitro ruptured human carotid plaque tissue.

Recent experimental studies performed on human carotid plaques have focused on mechanical characterization for the purpose of developing material models for finite-element analysis without quantifying the tissue composition or relating mechanical behaviour to preoperative classification. This study characterizes the mechanical and biological properties of 25 human carotid plaques and also investigates the common features that lead to plaque rupture during mechanical testing by performing circumferential uniaxial tests, Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) on each specimen to relate plaque composition to mechanical behaviour. Mechanical results revealed large variations between plaque specimen behaviour with no correlation to preoperative ultrasound prediction. However, FTIR classification demonstrated a statistically significant relationship between stress and stretch values at rupture and the level of calcification (P=0.002 and P=0.009). Energy-dispersive X-ray spectroscopy was carried out to confirm that the calcium levels observed using FTIR analysis were accurate. This work demonstrates the potential of FTIR as an alternative method to ultrasound forpredicting plaque mechanical behaviour. SEM imaging at the rupture sites of each specimen highlighted voids created by the nodes of calcifications in the tissue structure which could lead to increased vulnerability of the plaque.

Can augmentation index be used as an accurate tool in the diagnosis of peripheral obstructive arterial disease?

BACKGROUND: The use of radial augmentation index (rAI) as an indicator of vascular disease was investigated in the vascular imaging laboratory in a regional hospital. AIMS: The aim of this study was to investigate whether a correlation exists between ankle-brachial pressure index (ABPI) and rAI in normal subjects, patients with peripheral obstructive arterial disease, and diabetic patients. METHODS: A group of 46 patients and 14 controls had ABPI and rAI measured and factors affecting AI were assessed. RESULTS: rAI was found to have a negative correlation with ABPI (Spearman's ρ = -0.513, p < 0.01). There was significant increase in the rAI scores of diabetic patients compared to normal patients (normal median was 64% lower than diabetic median, p < 0.01) and in peripheral obstructive vascular disease patients compared to normal (normal median 69% lower, p < 0.001). Of the various affecting factors, age stood out with rAI having a positive correlation to age (Spearman's ρ = 0.68, p < 0.01). CONCLUSIONS: The augmentation index appears be a significant indicator of cardiovascular disease and may be a useful tool in the diagnosis of vascular pathology.

Initial experience of double-layer tension free reconstruction of abdominal wall defects with porcine acellular dermal collagen implant and polypropylene mesh.

INTRODUCTION AND AIM: Various techniques have been proposed for the repair of abdominal wall defects (AWD) with varying rates of success. Despite the development of new materials and modifications of surgical technique, no single approach has emerged as the optimum way to close large AWD. We report a method for repairing large incisional and recurrent abdominal wall hernias using a double-mesh technique. The defect is closed using an underlay biological implant and an onlay synthetic mesh, which is 'quilted' to the underlying abdominal wall and biological implant. The current study reports our initial experience with this approach in ten consecutive patients operated on for large AWD. METHODS: In this prospective observational study the following data were collected: age, gender, previous surgery, co-morbidities, situation and size of the defect, antibiotic therapy, hospital stay, postoperative complications and bacteriology in case of infection. The patients were reviewed at 1, 3 and 6 months, and 1-year postsurgery. RESULTS: Overall all ten AWD of ≥ 75 cm(2) were reconstructed successfully using the quilting technique. Median age of patients was 61 years (range 47-73 years); male:female ratio was 3:2 and median weight was 107.5 kg. Two patients developed a wound infection and were treated successfully with antibiotics. At median follow-up of 15.5 months (range 6-29 months) there was no case of recurrence. CONCLUSION: The use of double-layer of porcine acellular dermal collagen implant and polypropylene mesh in reconstruction of AWD can be considered a safe and effective treatment. The early short-term results are encouraging with few complications.

Comparison of arterial stiffness and microcirculatory changes following abdominal aortic aneurysm grafting.

BACKGROUND: Abdominal aortic aneurysm (AAA) surgery provides a unique opportunity to study the impact of arterial stiffness on central haemodynamics, reflected in augmentation index (AI). The aneurysmal aorta is significantly stiffer than undilated age-matched aorta. AIM: We investigated whether replacement of an aneurysmal aorta with a compliant graft would result in a decrease in AI, which would thus decrease myocardial workload parameters. METHODS: Patients undergoing elective open or endovascular AAA repair were assessed with applanation tonometry and laser fluximetry pre-operatively, immediately and long-term post-operatively. RESULTS: Replacement of a small segment of abnormal conduit vessel resulted in improvements in AI, demonstrating that arterial stiffness can be surgically manipulated. CONCLUSIONS: These results reflect a decreased myocardial workload post-aortic grafting. This decrease in AI is important from a risk factor management perspective, and arterial stiffness should become a further recognised and screened for risk factor in patients with known aneurysmal disease.

A computational study of the magnitude and direction of migration forces in patient-specific abdominal aortic aneurysm stent-grafts.

OBJECTIVES: Endovascular aneurysm repair for abdominal aortic aneurysm (AAA) is now a widely adopted treatment. Several complications remain to be fully resolved and perhaps the most significant of these is graft migration. Haemodynamic drag forces are believed to be partly responsible for migration of the device. The objective of this work was to investigate the drag forces in patient-specific AAA stent-grafts. METHODS: CT scan data was obtained from 10 post-operative AAA patients treated with stent-grafts. 3D models of the aneurysm, intraluminal thrombus and stent-graft were created. The drag forces were determined by fluid-structure interaction simulations. A worst case scenario was investigated by altering the aortic waveforms. RESULTS: The median resultant drag force was 5.46 N (range: 2.53-10.84). An increase in proximal neck angulation resulted in an increase in the resultant drag force (p = 0.009). The primary force vector was found to act in an anterior caudal direction for most patients. The worst case scenario simulation resulted in a greatest drag force of 16 N. CONCLUSIONS: Numerical methods can be used to determine patient-specific drag forces which may help determine the likelihood of stent-graft migration. Anterior-posterior neck angulation appears to be the greatest determinant of drag force magnitude. Graft dislodgement may occur anteriorally as well as caudally.

Improved assessment and treatment of abdominal aortic aneurysms: the use of 3D reconstructions as a surgical guidance tool in endovascular repair.

BACKGROUND: Endovascular repair is fast becoming the treatment of choice for abdominal aortic aneurysms in anatomically suitable patients. 3D reconstructions not only aid conventional 2D measurements but also allow further analyses of the vessel anatomy. METHODS: Computed tomography scan data for four male patients awaiting endovascular repair were obtained. 3D reconstructions were performed to determine measurements. Wall stress was determined on one particular case using finite element analysis. RESULTS: 3D reconstruction allows measurements to be obtained that can be difficult to determine using 2D images. This method complements traditional 2D approaches. Reconstructions also provided imaging of potential anatomical problems. Wall stress results showed key regions that may be possible rupture sites. CONCLUSION: 3D reconstructions greatly aid surgical planning. As stent-graft devices evolve, anatomical difficulties previously considered contraindications to endovascular repair can now be overcome with careful planning. 3D reconstruction is a useful adjunct to assessment and planning of endovascular repair.

Vascular trauma in an Irish regional hospital.

BACKGROUND: Vascular trauma is a common cause of mortality and morbidity worldwide. There are few accurate quantitative data available presently on the nature and outcome of these injuries. The aim of this study was to determine the incidence, aetiology, management and outcome of vascular injuries which required surgical intervention at a regional vascular unit. METHODS: All patients who suffered a vascular injury requiring surgical intervention between January 1992 and December 2005 were included. RESULTS: A total of 35 patients who underwent operative intervention for vascular trauma were reviewed. There were 26 men and 9 women with a median age of 26 years (range 3-80 years). Road traffic accidents accounted for 15 (43%) of all cases and 16 patients (47%) had an associated fracture. The brachial artery was most frequently injured, constituting 36% of all cases. Interposition grafting using the autogenous long saphenous vein was the most common procedure performed (11 patients). Eleven patients required a secondary procedure while the overall limb amputation rate was 8.5%. There was one mortality following an IVC injury. Seventy-four per cent of the cohort was asymptomatic at last follow-up. CONCLUSION: While vascular trauma is relatively uncommon in our catchment area it can be successfully managed. Most of the cases occur in young fit patients.