Meta-analysis of fenestrated endovascular aneurysm repair versus open surgical repair of juxtarenal abdominal aortic aneurysms over the last 10 years.

Background: Juxtarenal abdominal aortic aneurysms pose a significant challenge whether managed endovascularly or by open surgery. Fenestrated endovascular aneurysm repair (FEVAR) is now well established, but few studies have compared it with open surgical repair (OSR). The aim of this systematic review was to compare short- and long-term outcomes of FEVAR and OSR for the management of juxtarenal aortic aneurysms. Methods: A literature search was conducted of the Ovid Medline, EMBASE and PubMed databases. Reasons for exclusion were series with fewer than 20 patients, studies published before 2007 and those concerning ruptured aneurysms. Owing to variance in definitions, the terms 'juxta/para/suprarenal' were used; thoracoabdominal aortic aneurysms were excluded. Primary outcomes were 30-day/in-hospital mortality and renal insufficiency. Secondary outcomes included major complication rates, rate of reintervention and rates of endoleak. Results: Twenty-seven studies were identified, involving 2974 patients. Study designs included 11 case series, 14 series within retrospective cohort studies, one case-control study and a single prospective non-randomized trial. The pooled early postoperative mortality rate following FEVAR was 3·3 (95 per cent c.i. 2·0 to 5·0) per cent, compared with 4·2 (2·9 to 5·7) per cent after OSR. After FEVAR, the rate of postoperative renal insufficiency was 16·2 (10·4 to 23·0) per cent, compared with 23·8 (15·2 to 33·6) per cent after OSR. The major early complication rate following FEVAR was 23·1 (16·8 to 30·1) per cent versus 43·5 (34·4 to 52·8) per cent after OSR. The rate of late reintervention after FEVAR was higher than that after OSR: 11·1 (6·7 to 16·4) versus 2·0 (0·6 to 4·3) per cent respectively. Conclusion: No significant difference was noted in 30-day mortality; however, FEVAR was associated with significantly lower morbidity than OSR. Long-term durability is a concern, with far higher reintervention rates after FEVAR.

Antecedentes: Los aneurismas de la aorta abdominal yuxtarrenal plantean un gran reto sobre si tratarlos de forma endovascular o mediante cirugía abierta. La reparación del aneurisma con endoprótesis fenestrada (fenestrated endovascular aneurysm repair, FEVAR) no esta consolidada, sin embargo, algunos pocos estudios, la comparan con la reparación quirúrgica por vía abierta (open surgical repair, OSR). El objetivo de esta revisión sistemática fue comparar los resultados a corto y largo plazo de FEVAR y OSR para el tratamiento de los aneurismas aórticos yuxtarrenales. Métodos: Se llevó a cabo una búsqueda de la literatura en las bases de datos Ovid Medline, EMBASE y Pubmed. Las razones para exclusión fueron series con menos de 20 pacientes, aquellas publicadas antes de 2007 y los trabajos sobre aneurismas rotos. Debido a las diferencias en las definiciones, se utilizaron los términos "yuxta/para/suprarrenal"; se excluyeron los aneurismas de la aorta tóracoabdominal. Los resultados primarios fueron la mortalidad a 30 días/intrahospitalaria y la insuficiencia renal. Los resultados secundarios incluyeron las tasas de complicaciones mayores, tasa de reintervención y tasas de fugas internas. Resultados: Se identificaron un total de 27 estudios, que incluían 2.974 pacientes. Los diseños de los estudios incluían 11 series de casos, 12 estudios de cohortes retrospectivos, un estudio caso­control y un único ensayo no aleatorizado prospectivo. La mortalidad postoperatoria precoz agrupada tras FEVAR fue del 3,3% (i.c. del 95% 2,0­5,0), comparado con el 4,2% (i.c. del 95% 2,9­5,7) tras OSR. Después de FEVAR, la tasa de insuficiencia renal postoperatoria fue del 16,2% (i.c. del 95% 10,4­23,0) comparada con el 23,8% (i.c. del 95% 15,2­33,6) después de OSR. La tasa de complicaciones mayores precoces tras FEVAR fue del 23,1% (i.c. del 95% 16,8­30,1) comparada con el 43,5% (i.c. del 95% 34,4­52,8) después de OSR. La tasa de reintervención tardía tras FEVAR fue superior que tras OSR: 11,1% (i.c. del 95% 6,7­16,4) y 2,0% (i.c. del 95% 0,6­4,3), respectivamente. Conclusión: No se observaron diferencias significativas en la mortalidad a los 30 días, sin embargo, FEVAR presentó una morbilidad significativamente menor que OSR. La durabilidad a largo plazo es una preocupación con muchas mayores tasas de reintervención después de FEVAR.

Influence of psoas muscle area on mortality following elective abdominal aortic aneurysm repair.

BACKGROUND: The effect of sarcopenia based on the total psoas muscle area (TPMA) on CT is inconclusive in patients undergoing abdominal aortic aneurysm (AAA) intervention. The aim of this prospective cohort study was to evaluate morphometric sarcopenia as a method of risk stratification in patients undergoing elective AAA intervention. METHODS: TPMA was measured on preintervention CT images of patients undergoing elective endovascular aneurysm repair (EVAR) or open aneurysm repair. Mortality was assessed in relation to preintervention TPMA using Cox regression analysis, with calculation of hazard ratios at 30 days, 1 year and 4 years. Postintervention morbidity was evaluated in terms of postintervention care, duration of hospital stay and 30-day readmission. Changes in TPMA on surveillance EVAR imaging were also evaluated. RESULTS: In total, 382 patient images acquired between March 2008 and December 2016 were analysed. There were no significant intraobserver and interobserver differences in measurements of TPMA. Preintervention TPMA failed to predict morbidity and mortality at all time points. The mean(s.d.) interval between preintervention and surveillance imaging was 361·3(111·2) days. A significant reduction in TPMA was observed in men on surveillance imaging after EVAR (mean reduction 0·63(1·43) cm2 per m2 ; P < 0·001). However, this was not associated with mortality (adjusted hazard ratio 1·00, 95 per cent c.i. 0·99 to 1·01; P = 0·935). CONCLUSION: TPMA is not a suitable risk stratification tool for patients undergoing effective intervention for AAA.

Systematic review of endovascular intervention and surgery for common femoral artery atherosclerotic disease.

BACKGROUND: Endovascular intervention has emerged as a potential alternative to open surgery in treating common femoral artery (CFA) atherosclerotic disease. The aim of this systematic review was to assess the safety and efficacy of both techniques. METHODS: Thirteen electronic databases from 1980 to 3 January 2018 were searched. Study quality was assessed using the National Institute for Health and Care Excellence Interventional Procedure Programme quality assessment tool. Safety and efficacy outcome measures were analysed. RESULTS: Thirty-one studies reporting 813 endovascular procedures and 3835 endarterectomies were included. Only two small RCTs have been reported. The methodological quality of available studies was generally low and follow-up short. Safety endpoint assessment revealed a similar risk of wound haematoma for endovascular intervention and endarterectomy (5·5 (95 per cent c.i. 0·2 to 17·2) versus 3·9 (1·7 to 6·9) per cent respectively), a lower risk of wound infection with endovascular procedures (0 versus 5·9 (3·4 to 9·0) per cent) and a lower risk of wound lymph leakage (0 versus 5·7 (3·3 to 8·6) per cent). Efficacy endpoint assessment at 1 year identified that endovascular intervention had a lower primary patency rate than endarterectomy (78·8 (73·3 to 83·8) versus 96·0 (92·2 to 98·6) per cent respectively), a higher revascularization rate (16·0 (6·1 to 29·4) versus 5·8 (1·0 to 14·2) per cent) and a similar amputation rate (2·7 (1·2 to 4·8) versus 1·9 (0·7 to 3·8) per cent). CONCLUSION: Endovascular intervention of CFA disease appears to reduce the risk of wound complications but is associated with a lower patency rate and increased rates of subsequent revascularization procedures. Standardization of the endovascular technique and quantification of the proportions of patients suitable for either technique are required.

Coronary subclavian steal syndrome-is there a need for routine assessment for subclavian artery stenosis following coronary bypass surgery?

Subclavian artery stenosis (SAS) resulting in coronary subclavian steal syndrome (CSSS) is a common but under recognized pathology following coronary artery bypass surgery (CABG). Patients with SAS may be asymptomatic due to the sub-clinical diversion of blood flow from the myocardium and retrograde blood flow during catheter angiography in the left internal mammary artery (LIMA) may be the first suggestion of CSSS. The management of SAS, causing CSSS, may rarely require acute assessment and intervention. However, full anatomical assessment of the stenosis morphology may be limited on fluoroscopy. Correction of SAS may be essential to achieve effective reperfusion therapy.

Preservation of vascular endothelial repair in mice with diet-induced obesity.

INTRODUCTION: Preservation of structural integrity of the endothelial monolayer and maintenance of endothelial cell function are of critical importance in preventing arterial thrombosis, restenosis and atherosclerosis. Obesity has been intimately linked with endothelial dysfunction, and reports of reduced abundance and functional impairment of circulating progenitor cells in obesity have led to the suggestion that defective endothelial repair contributes to obesity-related cardiovascular disease. METHODS: C57BL/6 mice were fed a high-fat diet for either 3 or 6 months to induce obesity; metabolic phenotyping was then carried out before femoral artery wire injury was performed. Endothelial regeneration was then quantified. Mononuclear cells and myeloid angiogenic cells were cultured and characterized for pro-angiogenic properties. RESULTS: No impairment of endothelial regeneration following mechanical endothelial injury in diet-induced obese mice when compared with chow-fed controls was observed, despite the induction of an adverse metabolic phenotype characterized by glucose intolerance and insulin resistance. Dietary-obese mice had increased numbers of circulating myeloid angiogenic cells, which retained normal functional properties including intact paracrine angiogenic effects. CONCLUSION: Preserved endothelial regeneration despite metabolic dysregulation in dietary obese mice suggests that compensatory mechanisms mitigate the deleterious influence of insulin resistance on endothelial repair in obesity.

Modelling the growth of popliteal artery aneurysms.

BACKGROUND: Popliteal artery aneurysms (PAAs) comprise up to 85 per cent of all peripheral aneurysms. Few longitudinal studies track their progression. This study aimed to track the growth of asymptomatic PAAs in a hospital-based ultrasound service, and compare models of aneurysm growth. METHODS: This retrospective single-centre cohort study included patients who had a PAA on arterial duplex ultrasound imaging of the lower limbs between 1 January 2011 and 1 January 2016. Progression of PAA size and progression to event or intervention were the primary outcome measures. RESULTS: Some 282 images were analysed: 47 limbs with PAA were included in a cohort of 32 patients (15 had bilateral PAAs). Twenty patients also had an abdominal aortic aneurysm (AAA). Linear multilevel modelling estimated that PAA growth was 2·4 (95 per cent c.i. 1·6 to 3·7) mm a year. Growth was estimated at 0·8 (0·1 to 1·5) mm per year in patients without an AAA and 3·5 (2·9 to 4·2) mm per year in those with a known AAA (previous open repair, previous endovascular aneurysm repair or AAA under surveillance) (P < 0·001). CONCLUSION: Growth rates of PAA were heterogeneous but were optimally predicted by multilevel modelling. Patients with an existing AAA may have faster PAA progression than those without.

Meta-analysis of the association between alcohol consumption and abdominal aortic aneurysm.

BACKGROUND: Alcohol is a possible risk factor for abdominal aortic aneurysm (AAA), but evidence from individual studies is weak and inconsistent. Existing narrative reviews suggest the possibility of non-linear associations. The aim here was to quantify any association using a systematic literature review, followed by dose-response meta-analysis of prospective studies. METHODS: MEDLINE, Embase and Web of Science were searched systematically to January 2017 for relevant prospective studies of alcohol consumption and AAA risk. Summary estimates of highest versus lowest levels of consumption, and linear and non-linear dose-response curves were quantified using random-effects models. RESULTS: Eleven relevant cohorts were identified describing results from 3580 individuals with among 473 092 participants. Data were extracted from ten cohorts for meta-analyses of high versus low levels of alcohol consumption (risk ratio for AAA 0·93, 95 per cent c.i. 0·78 to 1·11; P = 0·4, I2 = 47 per cent). The linear dose-response risk ratio for AAA, derived from 11 cohorts, was 1·00 (0·97 to 1·04) per 8 g alcohol per day (P = 0·9, I2 = 73 per cent). Non-linear dose-response results showed a tick-shaped curve with lower risk up to 2 units/day, but increasing risk beyond that (P = 0·05). The increase in risk beyond 2 units/day was stronger in men than in women. CONCLUSION: Although the linear dose-response analysis revealed little evidence of an association between alcohol consumption and AAA risk, a tick-shaped trend in the association was observed. This non-linear dose-response analysis revealed reduced risks for alcohol consumption below 2 units/day, masking increased risks for 2 or more units/day.

Aspirin therapy is associated with less compact fibrin networks and enhanced fibrinolysis in patients with abdominal aortic aneurysm.

OBJECTIVE: Thrombotic changes in fibrin networks contribute to increased cardiovascular risk in patients with abdominal aortic aneurysm (AAA). Given that aspirin modulates the fibrin network, we aimed to determine if aspirin therapy is associated with changes in ex-vivo fibrin clot characteristics in AAA patients and also conducted an exploratory analysis of 5-year mortality in these individuals. METHODS: We recruited 145 male patients, divided into controls (aortic diameter < 3 cm, n = 49), AAA not taking aspirin (AAA-Asp, n = 50) and AAA on 75 mg day(-1) aspirin (AAA+Asp, n = 46), matched for aneurysm size. Characteristics of clots made from plasma and plasma-purified fibrinogen were investigated using turbidimetric analysis, permeation studies, and confocal and electron microscopy. Plasma fibrinogen, D-dimer and inflammatory marker levels were also measured. RESULTS: Maximum absorbance (MA) of plasma clots from controls was lower than that of AAA patients not on aspirin (AAA-Asp) at 0.30 ± 0.01 and 0.38 ± 0.02 au, respectively (P = 0.002), whereas aspirin-treated subjects had MA similar to controls (0.31 ± 0.02 P = 0.9). Plasma clot lysis time displayed an identical pattern at 482 ± 15, 597 ± 24 and 517 ± 27 s for control, AAA-Asp and AAA+Asp (P = 0.001 and P = 0.8). The lysis time of clots made from purified fibrinogen of AAA-Asp was longer than that of AAA+Asp patients (756 ± 47 and 592 ± 52 s, respectively; P = 0.041). Permeation studies and confocal and electron microscopy showed increased clot density in AAA-Asp compared with the AAA+Asp group. Mortality in AAA-Asp and AAA+Asp was similar, despite increased cardiovascular risk in the latter group, and both exhibited higher mortality than controls. CONCLUSION: Aspirin improves fibrin clot characteristics in patients with AAA, which may have important clinical implications.

Cardiovascular risk in patients with small and medium abdominal aortic aneurysms, and no history of cardiovascular disease.

BACKGROUND: Cardiovascular disease (CVD) is the main cause of death in people with abdominal aortic aneurysm (AAA). There is little evidence that screening for AAA reduces all-cause or cardiovascular mortality. The aim of the study was to assess whether subjects with a small or medium AAA (3·0-5·4 cm), without previous history of clinical CVD, had raised levels of CVD biomarkers or increased total mortality. METHODS: This prospective study included subjects with a small or medium AAA and controls, all without a history of clinical CVD. CVD biomarkers (high-sensitivity C-reactive protein, hs-CRP; heart-type fatty acid-binding protein, H-FABP) were measured, and survival was recorded. RESULTS: Of a total of 815 people, 476 with an AAA and 339 controls, a cohort of 86 with small or medium AAA (3-5·4 cm) and 158 controls, all with no clinical history of CVD, were identified. The groups were matched for age and sex. The AAA group had higher median (i.q.r.) levels of hs-CRP (2·8 (1·2-6·0) versus 1·3 (0·5-3·5) mg/l; P < 0·001) and H-FABP (4·6 (3·5-6·0) versus 4·0 (3·3-5·1) µg/l; P = 0·011) than controls. Smoking was more common in the AAA group; however, hs-CRP and H-FABP levels were not related to smoking. Mean survival was lower in the AAA group: 6·3 (95 per cent confidence interval (c·i.) 5·6 to 6·9) years versus 8·0 (7·6 to 8·1) years in controls (P < 0·001). Adjusted mortality was higher in the AAA group (hazard ratio 3·41, 95 per cent c·i. 2·11 to 9·19; P < 0·001). CONCLUSION: People with small or medium AAA and no clinical symptoms of CVD have higher levels of hs-CRP and H-FABP, and higher mortality compared with controls. They should continue to receive secondary prevention against CVD.

Lymphangiogenesis in abdominal aortic aneurysm.

BACKGROUND: Ongoing angiogenesis is implicated in the inflammatory environment that characterizes abdominal aortic aneurysm (AAA). Although lymphangiogenesis has been associated with chronic inflammatory conditions, it has yet to be demonstrated in AAA. The aim was to determine the presence of lymphangiogenesis and to delineate the relationship between inflammation and neovascularization in AAA tissue. METHODS: AAA samples and preoperative computed tomography images were obtained from patients undergoing elective AAA repair. Control samples were age-matched abdominal aortic tissue. Specific immunostains for blood vessels (CD31, CD105), lymphatic vessels (D2-40), vascular endothelial growth factor (VEGF) A and VEGF receptor (VEGFR) 3 allowed characterization and quantitation of vasculature. RESULTS: The AAA wall contained high levels of inflammatory infiltrate; microvascular densities of blood (P < 0·001) and lymphatic (P = 0·003) vessels were significantly increased in AAA samples compared with controls. Maximal AAA vascularity was observed in inflammatory areas, with vessels that stained positively for CD31 (ρ = 0·625, P = 0·017), CD105 (ρ = 0·692, P = 0·009) and D2-40 (ρ = 0·675, P = 0·008) correlating positively with the extent of inflammation. Increased VEGFR-3 and VEGF-A expression was also evident within inflammatory AAA areas. CONCLUSION: These findings demonstrated lymphatic vessel involvement in end-stage AAA disease, which was associated with the degree of inflammation, and confirmed the involvement of neovascularization.

Early re-presentations and the potential role of catheter-directed thrombolysis in patients diagnosed with a lower limb deep vein thrombosis: a single-centre experience.

INTRODUCTION: Catheter-directed thrombolysis (CDT) for iliofemoral deep vein thrombosis (DVT) restores venous patency, reduces the risk of the post-thrombotic syndrome and may reduce longer term treatment costs. This study assessed the potential role of CDT in patients with DVT with regard to representation following the index event. METHODS: A retrospective review of all patients with a positive lower limb DVT scan. Potential suitability of each patient to undergo CDT was based on well-recognized inclusion/exclusion criteria. RESULTS: In total, 1689 patients underwent a DVT-specific lower limb venous duplex. A total of 269 were found to have a DVT. Fifty-three of these patients met the inclusion criteria for CDT (only 2 underwent CDT). Fifty-nine of the 269 patients with an index DVT re-presented to our institution with a venous thromboembolism-related clinical event. These patients were significantly younger than those who did not reattend. A higher proportion of patients who represented were deemed suitable for CDT for the index DVT compared with those who did not represent (17/59 versus 36/210; P = 0.04). CONCLUSION: This pragmatic study highlights the fact that significant number of patients return to secondary care with actual/perceived complications following initial diagnosis and treatment of a DVT which may have been amenable to CDT.

Meta-analysis of prospective trials determining the short- and mid-term effect of elective open and endovascular repair of abdominal aortic aneurysms on quality of life.

BACKGROUND: Repair of an abdominal aortic aneurysm (AAA) is undertaken to prevent rupture. Intervention is by either open repair (OR) or a more minimally invasive endovascular repair (EVAR). Quality-of-life (QoL) analysis is an important health outcome and a number of single studies have assessed QoL following OR and EVAR. This was a meta-analysis of published studies to assess the effect of an intervention on QoL in patients with an AAA. METHODS: A systematic literature search was undertaken for studies prospectively reporting QoL analysis in patients with an AAA undergoing elective intervention. A multivariable meta-analysis model was developed in which the outcomes were mean changes in QoL scores over time, both for all AAA repairs (OR and EVAR) and comparing OR with EVAR. RESULTS: Data were collated from 16 studies (14 OR, 12 EVAR). The results suggested that treating an AAA had an effect on patient-reported QoL, evident from the statistically significant changes predominantly in domains assessing physical ability and pain. QoL was affected most within the first 3 months after any form of intervention, and was more pronounced following OR. Furthermore, a deterioration in the Physical Component Summary score following an AAA repair (either OR or EVAR) was evident at 12 months after intervention. CONCLUSION: Treating an AAA deleteriously affects patient-reported QoL over the first year following intervention.

Ovarian mass causing paradoxical MI and leg ischaemia.

Paradoxical embolus through a patent foramen ovale is a well-reported phenomenon. Clinical consequences include stroke, intestinal infarction, lower limb ischaemia, and even acute myocardial infarction (MI), via embolisation to the coronary arteries. We present a case of acute MI, cardiogenic shock, and cardiac arrest caused not by this mechanism, but by embolisation of thrombotic material to the aortic root with transient complete occlusion of the left main stem (LMS) coronary artery. During percutaneous coronary intervention to treat this occlusion the thrombus became lodged at the aortic bifurcation causing lower limb ischaemia. Despite successful treatment of this via bilateral groin exploration and thromboembolectomy the patient became increasingly acidotic and an abdominal and pelvic CT scan was performed. This revealed the source of the thrombus to be the patient's congested and compressed pelvic veins which were the result of a large, previously undiagnosed ovarian malignancy with metastatic spread. Although very unusual we feel this case highlights an important differential in the diagnosis of anterolateral MI and images similar to those presented here are previously unreported in the literature.

Compression of the dorsalis pedis artery: a novel cause of blue toe syndrome.

Blue toe syndrome (BTS) is an important vascular condition characterized by painful blue discoloration of one or more digits. It is frequently due to emboli and is important because of the risk of progressive ischemia and tissue loss. A 53-year-old male presented with recurrent episodes of painful blue discoloration and blistering of the skin of the right hallux. On examination, the patient was found to have a cool, blue-purple great toe; all peripheral pulses were present. The patient was investigated for coagulopathy and potential sources of emboli, but the only abnormality was significant stenosis of the dorsalis pedis artery due to extrinsic compression by the extensor hallucis brevis tendon. In the absence of any other embolic source or abnormality, we believe that this case presents a novel and potentially remediable cause of BTS and indicates the need for a careful search for an underlying lesion when common causes of BTS have been excluded.

Femoral artery dissection in vascular type Ehlers-Danlos syndrome; leave well alone?

Vascular Ehlers-Danlos Syndrome (EDS) is a rare autosomal dominant condition resulting from a defect in type III procollagen synthesis. This causes the development of severe vascular pathologies, including arterial rupture and pseudoaneurysm formation. We present a case of a young boy previously diagnosed with vascular EDS due to a Gly975Val substitution in the collagen α1(III) chain presenting with a common femoral artery dissection secondary to minimal trauma. This was managed conservatively with serial duplex scans and gentle mobilization. At follow up the patient had returned to normal activities, with MRA and duplex scans showing complete resolution of the dissection.

Aberrant medial sural artery causing popliteal vein entrapment syndrome.

Isolated popliteal venous entrapment is unusual and often caused by variation or aberrant origins of the gastrocnemius muscle, thickened perivenous fascia or an abnormal vascular bundle. We report a unique case of a fit and well 35-year-old man with popliteal venous entrapment after presenting to the vascular unit with symptomatic varicose veins. The cause of the entrapment was found to be an aberrant medial sural artery on operative exploration. The artery was ligated, releasing the entrapped vein. The patient made an uneventful recovery with resolution of symptoms of venous insufficiency without evidence of muscle ischaemia.

Agreement between computed tomography and ultrasound on abdominal aortic aneurysms and implications on clinical decisions.

OBJECTIVES: The United Kingdom abdominal aortic aneurysm (AAA) screening programme refers aneurysms with ultrasound (US) diameters of ≥5.5 cm to vascular services for consideration of computed tomography (CT) and intervention. We investigated the discrepancy between US and CT, implications on clinical decisions and question at which stage CT be used. DESIGN/METHODS: AAA USs over 5 years were retrospectively analysed. Patients included had aneurysms measuring ≥5 cm on US with subsequent CT within 2 months (n = 123). Based on maximum US diameters, 44 patients had aneurysms between 5 and 5.4 cm (group I) and 79 patients ≥5.5 cm (group II). Results were cross-referenced. Correlation and limits of agreement were calculated. Two radiologists re-measured 44 pairs of CT/US scans and the inter-observer bias in determining discrepancies between imaging modalities calculated. RESULTS: Mean difference between imaging modalities was 0.21 cm (±0.39 cm, p < 0.001). Limits of agreement were -0.55 to 0.96 cm, exceeding clinical acceptability. Mean difference was higher and significant in group I (0.39 cm, p < 0.001) compared to group II (0.10 cm, p > 0.05). Seventy-percent of group I patients had CT scans revealing diameters of ≥5.5 cm. Inter-observer bias was not significant. CONCLUSION: Significant differences between imaging modalities, more in US diameters of below 5.5 cm, exist. We recommend AAAs measuring ≥5 cm on US should undergo earlier referral to a vascular service and CT.

Reproducibility of ultrasound measurement of the abdominal aorta.

BACKGROUND: Abdominal aortic aneurysm (AAA) screening and surveillance programmes use ultrasound imaging to measure the anteroposterior (AP) diameter of the infrarenal aorta. The aim of this study was to examine potential observer bias and variability in ultrasound measurements. METHODS: Studies were identified for review via a MEDLINE database search (1966-2009). References supplied in accessed papers were also checked for potential relevance. Consistent search terminology, and inclusion and exclusion criteria were used to ensure quality of data. Nine papers were available to review. RESULTS: Variation in intraobserver repeatability and interobserver reproducibility was identified. Six studies reported intraobserver repeatability coefficients for AP aortic diameter measurements of 1·6-4·4 mm. These were below the 5-mm level regarded as acceptable by the UK and USA AAA screening programmes. Five studies had interobserver reproducibility below the level of 5 mm. Four studies, however, reported poor reproducibility (range from -2 to +5·2 to -10·5 to +10·4); these differences may have had a significant clinical impact on screening and surveillance. CONCLUSION: The studies used different methodologies with no standardized measurement techniques. Measurements were taken by observers from different medical disciplines of varying grade and levels of training. Standard training and formal quality assurance of ultrasound measurements are important components of an effective AAA screening programme.