Objectives The purpose of this study is investigate the effects of variants in the apolipoprotein(a) gene ( LPA ) on vascular diseases with different atherosclerotic and thrombotic components. ...Background It is unclear whether the LPA variants rs10455872 and rs3798220, which correlate with lipoprotein(a) levels and coronary artery disease (CAD), confer susceptibility predominantly via atherosclerosis or thrombosis. Methods The 2 LPA variants were combined and examined as LPA scores for the association with ischemic stroke (and TOAST Trial of Org 10172 in Acute Stroke Treatment subtypes) (effective sample size ne = 9,396); peripheral arterial disease ( ne = 5,215); abdominal aortic aneurysm ( ne = 4,572); venous thromboembolism ( ne = 4,607); intracranial aneurysm ( ne = 1,328); CAD ( ne = 12,716), carotid intima-media thickness (n = 3,714), and angiographic CAD severity (n = 5,588). Results LPA score was associated with ischemic stroke subtype large artery atherosclerosis (odds ratio OR: 1.27; p = 6.7 × 10–4 ), peripheral artery disease (OR: 1.47; p = 2.9 × 10–14 ), and abdominal aortic aneurysm (OR: 1.23; p = 6.0 × 10–5 ), but not with the ischemic stroke subtypes cardioembolism (OR: 1.03; p = 0.69) or small vessel disease (OR: 1.06; p = 0.52). Although the LPA variants were not associated with carotid intima-media thickness, they were associated with the number of obstructed coronary vessels (p = 4.8 × 10–12 ). Furthermore, CAD cases carrying LPA risk variants had increased susceptibility to atherosclerotic manifestations outside of the coronary tree (OR: 1.26; p = 0.0010) and had earlier onset of CAD (–1.58 years/allele; p = 8.2 × 10–8 ) than CAD cases not carrying the risk variants. There was no association of LPA score with venous thromboembolism (OR: 0.97; p = 0.63) or intracranial aneurysm (OR: 0.85; p = 0.15). Conclusions LPA sequence variants were associated with atherosclerotic burden, but not with primarily thrombotic phenotypes.
Abstract Objective This study aimed to determine the prevalence and relevance of incidental abdominal aortic aneurysm (AAA) on routine abdominal computed tomography (CT) and to audit the performance ...of radiologists to identify and report AAA. Methods A retrospective audit of all abdominal CT scans performed on men and women ≥50 years at Dunedin Public Hospital between January 2013 and September 2014 was carried out. All CT scans for planning of AAA treatment or follow-up were excluded. The maximal anterior-posterior diameter of the infrarenal abdominal aorta was measured in both the sagittal and transverse planes on the picture archiving and communication system. The radiologist reports were analyzed. All detected AAAs were reviewed for clinical relevance. Results A total of 3332 scans were performed, of which 86 scans were excluded, resulting in a total cohort of 3246. There were 187 incidental AAAs detected with a prevalence of 5.8%. The prevalence was 8.7% in men and 3.1% in women. Whereas the prevalence increased with age, a significant number were detected in those younger than 65 years, with a prevalence of 1.5%. Of the 187 AAAs, 122 (65%) were reported by radiologists: 100% reporting rate in AAAs ≥50 mm, 87% in AAAs ≥40 to 49 mm, and 52% in AAAs ≥30 to 39 mm. Of these, 15% were specifically recommended for referral to a vascular service. Of the incidentally detected AAAs, 72% were considered to be clinically relevant, which is an overall 4.1% prevalence of AAAs with an ability to benefit. In addition, all 3246 subjects avoided the need for further AAA screening. Conclusions There is a high prevalence of AAAs (5.8%) and clinically relevant AAAs (4.1%) detected on routine abdominal CT. As an opportunistic approach, it is a simple and effective way to detect AAAs and to broaden traditional screening criteria to include women and those younger than 65 years in our region. Furthermore, large numbers of subjects with normal aortic diameters are identified who will not need to be screened. Consequently, we consider routine diagnostic abdominal CT to be an important adjunct to national and community AAA screening strategies.
Objective To determine the role of microvenous valves in the superficial venous system in the prevention of reflux and skin changes in the progression of venous insufficency. Methods The venous ...anatomy of 15 amputated lower limbs, eight free from clinical venous disease and seven with varicose veins and ulcers, was examined using retrograde venography corrosion casting. Prior to amputation, all limbs were scanned by duplex ultrasound to confirm the presence or absence of reflux in the great (GSV) and small saphenous veins or their tributaries. The resulting resin casts were photographed and mapped to show the position, orientation, and competency of valves in the superficial venous network. Casts were also examined by scanning electron microscopy. Results Retrograde venous filling was demonstrated in the “normal” limbs despite a competent GSV. Microvalves were identified down to the sixth generation of tributaries from the GSV. Only in regions where incompetence existed in microvalves out to the third (ie, the “boundary”) generation was the resin able to penetrate deeper into microvenous networks of the dermis. This was despite the presence of subsequent competent valves, which were able to be bypassed in the network. In limbs with varicose veins and venous ulcers, reflux into the small venous networks and capillary loops was more extensive with more dense networks and greater tortuousity. Conclusions This study demonstrates that valvular incompetence can occur independently in small superficial veins in the absence of reflux within the GSV and the major tributaries. We have shown that once there is incompetence of the third generation “boundary” microvalves, reflux can extend into the microvenous networks in the skin. These effects are markedly worse in the presence of GSV incompetence. We propose that degenerative changes with valve incompetence are required in both the larger proximal vessels and the small superficial veins, in particular at the “boundary” valve level, for the severe skin changes in venous insufficiency to occur.
Aortoduodenal syndrome is a rare clinical entity characterized by an upper gastrointestinal obstruction in association with an abdominal aortic aneurysm. The exact mechanism of obstruction is ...unknown. We present a case of aortoduodenal syndrome and discuss the interplay of the aneurysm and duodenum in the development of the duodenal obstruction.
Objective This prospective study sought to track the natural history of duplex ultrasound (DUS) detected varicose vein recurrence in the groin after surgical intervention during a 5-year period. ...Methods Patients were recruited from a previous prospective trial investigating outcomes after high ligation and stripping with and without patch saphenoplasty. Follow-up examinations of the lower limb venous systems using DUS, air plethysmography, and clinical assessment were carried out at 1, 6, 12, and 36 months. At 60 months, an additional detailed DUS scan of the groin was performed on those with recurrence, including vessel numbers, diameter, and reflux velocity, to characterize the state of this groin recurrence. Results In the 130 limbs at 5 years, ultrasound groin recurrence was detected in 82%, and visible varicose veins occurred in 83% (108 limbs). In contrast, recurrence with severe varices occurred in 47% (61 limbs) as clinical recurrence (Venous Clinical Severity Score less the stocking component >3) in 22% (29 limbs) and functional recurrence (venous filling index >2 mL/s) in 34% (43/125 limbs). The DUS pattern was junctional in 29 limbs (22%), nonjunctional in 37 limbs (29%), and mixed pattern in 40 limbs (31%). Compared with the 24 (19%) with no ultrasound-detected recurrence, severe visible varicose veins were significantly more common with each of these patterns and especially with multiple connecting vessels (odds ratio, 5.4; confidence interval, 1.5-19.5). The diameter and velocity of reflux through recurrent vessels in the groin did not correlate with disease severity, and no DUS feature in the groin was predictive of Venous Clinical Severity Score >3 or a venous filling index >2 mL/s. The appearance of DUS recurrence within the first year and other features, including residual lower leg reflux, body mass index, gender, and previous treatment, were more consistent predictors. Conclusions Early ultrasound recurrence is predominantly evidence of neovascularization and some small-vessel remodeling at the site of treatment. When it occurs, some visible varicose veins are inevitable. However, these appearances alone are not good predictors of severe clinical recurrence.
Objective Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and ...characterize a pig-based model of superficial varicose veins. Methods Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins. Results Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening. Conclusions The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.
Background Deep venous reflux (DVR) is often a poorly defined clinical entity. The extent of DVR that must occur for it to be clinically and hemodynamically important is not clear and is usually ...confounded by the presence of superficial venous reflux. This study aims to investigate the effect of the extent of DVR on clinical and hemodynamic parameters while controlling for the presence of superficial reflux. Methods We performed a cross-sectional study, using a prospectively designed data set obtained from patients presenting to a vascular laboratory for lower limb venous assessment. Age, gender, duplex ultrasound assessment of the deep and superficial systems, CEAP clinical class, and venous filling index (VFI) measurements were obtained. A classification of axial DVR is described, based on the level of continuous reflux occurring in the vertical axis as detected by duplex ultrasound: axial 0 (no deep reflux), axial 1 (common femoral vein only), axial 2 (to any level of the femoral vein), axial 3 (to the level of the popliteal vein), and axial 4 (into the calf veins) A subset of segmental reflux is also defined. Results This study included 3122 limbs from 2349 subjects. Limbs with increasing axial level were more likely to have CEAP 4-6 (axial 0: 294 37.2%; axial 1: 520 41.6%; axial 2: 82 41.2%; axial 3: 92 59.7%; axial 4: 148 64.9%, P value for trend <.0001). This relationship remained highly significant following adjustment for superficial reflux and demographic variables. Compared with limbs with no DVR, the adjusted odds ratio for having CEAP 4-6 was 2.10 (1.25-3.51; P < .0048) for limbs with axial level 3 and 3.07 (1.94-4.88, P < .0001) for limbs with axial level 4. Similarly after adjustment, predicted mL/s increases in VFI were significant ( P < .0001) for level 1 (1.19 1.08-1.31), level 3 (1.53 1.31-1.78), and level 4 (1.74 1.51-1.95). Segmental reflux, when extensive, also contributed to the risk of more severe disease. Conclusions Deep axial reflux to the level of the knee and calf is associated with more severe venous disease and greater VFI, independently of reflux in the superficial system. A system of classification of DVR is recommended.
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