Angiography and phlebography in a hemodialysis population: A retrospective analysis of interventional results.

OBJECTIVE: To clarify the reasons and beneficial effects and duration of arteriovenous fistula patency after radiological interventions in arteriovenous fistula. The patients investigated were referred due to arteriovenous fistula access flow problems. MATERIAL AND METHODS: In 174 patients, 522 radiological investigations and endovascular treatments such as percutaneous transluminal angioplasty were analyzed, retrospectively. All investigations were performed due to clinical suspicion of impaired arteriovenous fistula function. RESULTS: Arterial stenosis was significantly more frequent among patients with diabetic nephropathy (p < 0.001) and interstitial nephritis (p < 0.001). According to the venous stenosis, the diagnosis did not affect the frequency (p = 0.22) or the degree (p = 0.39) of stenosis. The degree of stenosis prior to percutaneous transluminal angioplasty correlated significantly with the degree of remaining stenosis after intervention (p < 0.001). Of the 174 patients, 123 (71%) performed a total of 318 investigations including percutaneous transluminal angioplasty. Repeated percutaneous transluminal angioplasty was performed significantly more often in patients with diabetic nephropathy. The median times to the first percutaneous transluminal angioplasty and to the subsequent percutaneous transluminal angioplasties were 9.5 and 5 months, respectively. Arteriovenous fistula in patients with diabetic nephropathy performed similar to most other diagnoses, although performing more percutaneous transluminal angioplasty/patient than most other diagnoses. CONCLUSION: Many patients could maintain long-term patency of arteriovenous fistula, including those with diabetic nephropathy, with repeated interventions; this motivates a closer follow-up for these patients. Clinically significant stenosis should be dilated as meticulously and as soon as possible. Occlusions of the arteriovenous fistula in most instances can be successfully thrombolyzed or dilated upon early diagnosis.

A national survey on management of varicose veins in China.

OBJECTIVE: This study aimed to investigate the current clinical practice and management strategies for varicose veins among Chinese physicians in general and in specific case vignettes. METHODS: A questionnaire survey was conducted among 726 Chinese physicians who were attending the vascular surgery academic conferences during August 2016 to May 2017 in China. Physicians were eligible if they were familiar with several currently used treatment techniques for varicose veins. RESULTS: A total of 681 physicians from 527 hospitals in 29 provinces across China completed the questionnaire. Of them, 80.0% were vascular surgeons, 13.1% were general surgeons, and 6.9% were interventional radiologists. More than half (67.0%) of them had >5 years of experience in management of varicose veins. A third of the participants performed routine venography for patients with suspected varicose veins. Moreover, 87.5% believed that the patient's medical insurance would influence their choice of treatment modalities. Only 38.5% of the participants' departments could perform day surgery for varicose veins. The most common average hospitalization time was 4 to 7 days, with an average cost of 4000 to 8000 yuan per leg. In the basic case (Clinical, Etiology, Anatomy, and Pathophysiology classification C2,SEpAsPr2,3), 63.8% preferred traditional surgery for great saphenous vein reflux, followed by endovenous laser ablation (24.3%), radiofrequency ablation (5.6%), and ultrasound-guided foam sclerotherapy (3.1%). Physicians in coastal China were more likely to choose endovenous thermal ablation than those from western China (P < .05). In modified case vignettes complicated with hyperpigmentation and lipodermatosclerosis or ulceration, more participants chose traditional surgery for great saphenous vein (73.2% vs 63.8% [P < .001]; 75.9% vs 63.8% [P < .001]) compared with the basic case. Moreover, 31.9% preferred continuation of compression therapy for patients with varicose veins and deep venous reflux, and 65.4% preferred correction of iliac vein compression before treatment of varicose veins. Distributions of management strategies were significantly different between the basic and modified case vignettes (all P < .01). CONCLUSIONS: Both traditional surgery and minimally invasive techniques are used for patients with varicose veins in China, but traditional surgery is the mainstay of treatment for varying degrees of varicose veins. Related clinical factors, duplex ultrasound scan findings, medical insurance, and economy may have influenced the physicians' choice of treatment modality for varicose veins.

Angiografia dos dígitos de bovinos jovens antes e após indução de acidose ruminal / Digital angiography in young cattle before and after ruminal acidosis induction

O presente estudo objetivou descrever a rede vascular dos dígitos dos membros pélvicos de bovinos antes e após aplicação intrarruminal de oligofrutose, empregando a venografia. Utilizaram-se seis bovinos alocados em dois grupos (GI e GII), que receberam 13 e 17g/kg de oligofrutose, respectivamente. A venografia dos dígitos foi feita em quatro momentos: 15 dias antes (M0) e 36 horas (M1), sete dias (M2) e 30 dias (M3) após aplicação de oligofrutose. Mensurou-se a largura das veias visualizadas e avaliou-se possível supressão do fluxo sanguíneo dos vasos. A largura foi avaliada pela análise de variância (ANOVA) e pelo teste t (5%). Em M0, nas radiografias, foram identificadas 25 estruturas, incluindo veias, artérias e rede vascular. As veias mensuradas foram: digital dorsal comum III e dorsal da falange distal e os ramos plantares para o coxim digital do dígito lateral e medial. Apenas a v. digital dorsal comum III apresentou maior largura após 36 horas e constrição com 30 dias (P≤0,05) da aplicação de oligofrutose. Comparando-se os momentos, encontrou-se vasodilatação no M1 e vasoconstrição nos demais. A mensuração da largura dos vasos não sofreu (P≥0,05) interferência quando se compararam os grupos. Concluiu-se que a venografia dos dígitos de bovinos permite estudar e identificar alterações da vascularização.(AU)

The objective of this study was to describe vascular net of bovine digit before and after intrarruminal administration of oligofructose, with the use of venography. Six animals sorted in two groups (GI and GII) that received 13 and 17g/kg of oligofructose respectively were used. Digits venography were done in four moments: 15 days before (M0) and 36 hours (M1), seven days (M2) and 30 days (M3) after administration of oligofructose. Width of visualized veins and evaluated possible blood flow vessels suppression was measured. The width was evaluated by ANOVA and T test (5%). In M0 25 structures were identified, including veins, arteries and vascular net in radiographic images. Veins measured were: common digital III and dorsal of distal phalanx and plantar branches to digital cushion of lateral and medial digits. Only V. digital dorsal common III presented higher width after 36 hours and constriction with 30 days (P≤0.05) of oligofructose administration. Comparing moments, vessel dilation on M1 and constriction on other moments. Measurement of vessel width didn´t suffer interference when groups were compared. Venography of bovine digits allowed for the study and identification of changes in vascularization.(AU)

Material Failure of Silicone Catheter Lines: A Retrospective Review of Partial and Complete Ruptures in 553 Patients.

OBJECTIVE: This present study reports the frequency and outcome of material failure of the silicone catheter lines of a port device implanted in the upper arm during a 5-year period. MATERIALS AND METHODS: From 2006 to 2011, a total of 553 patients had a port device implanted percutaneously in the upper arm. In the spring of 2013, several instances of material failure led to device withdrawal. At that time, 39 patients (7.1%) with the specific device in situ were still alive, and 36 of these patients agreed to removal. Linear mixed-effects models were used to analyze the log-transformed device dwell time. Random effects were modeled using group variables. The mean estimated values and their corresponding 95% CIs were reported. Nominal p values were reported, and two-sided p < 0.05 was considered to denote statistical significance. RESULTS: Among the 553 patients, material failure was noticed in 19 patients (3.4%), with a mean estimated dwell time of 243 days (95% CI, 104-570 days). Specifically, complete rupture occurred in 10 patients (1.8%) after a mean of 322 days (95% CI, 95-1089 days), partial rupture occurred in eight patients (1.4%) after a mean of 190 days (95% CI, 61-596 days), and disconnection occurred in one patient (0.2%) 8 days after device placement. CONCLUSION: The frequency of catheter line rupture was 3.4%. The mean estimated interval to rupture was less than a year, with an increasing probability of rupture noted in association with a longer dwell time. The exact cause of material failure remains unexplained, and further investigation of the mechanical properties contributing to rupture is required. Insight into the safety profile of these devices is needed to avoid potentially severe injury and improve the management of affected patients.

Inferior vena cava calibre on paediatric trauma CT may be a useful predictor for the development of shock.

AIM: To investigate whether inferior vena cava (IVC) calibre on paediatric trauma computed tomography (CT) can help anticipate outcomes in children. MATERIALS AND METHODS: The imaging and clinical records of 52 paediatric trauma admissions to the level 1 major trauma centre at St George's Hospital, London, UK, were retrospectively reviewed. The IVC dimensions, evidence of significant haemorrhage on CT, and the presence of components of the classical hypoperfusion complex, such as bowel and adrenal hyperenhancement, were recorded. Clinical data included observations at the time of admission and for the subsequent 48-hour period where available, blood gas results, length of stay, and mortality. RESULTS: There was a significant relationship between IVC dimensions in this cohort and the development of shock during the 24-hour admission period. IVC dimensions did not, however, reflect the haemodynamic status at the time of admission, and were not predictive of a longer hospital stay. There were no mortalities among the cases. A weak correlation was also seen with serum lactate, a finding that has also been seen in adults, but is of uncertain clinical significance. CONCLUSIONS: IVC calibre was found to be a more useful predictor of shock than heart rate or blood pressure, and may, therefore, prove to be a useful predictor of impending haemodynamic instability in children as it is in adults. Although the study was carried out at a busy unit, the numbers are acknowledged to be small and a larger study would be needed to validate these findings and identify whether there is any variation in the CT appearances between different age groups.

Penetration of Celect inferior vena cava filters: retrospective review of CT scans in 265 patients.

OBJECTIVE: The purpose of this study is to retrospectively evaluate the prevalence and extent of Celect inferior vena cava (IVC) filter penetration. MATERIALS AND METHODS: All patients with Celect filters who underwent CT between 2007 and 2012 were assessed for penetration and related complications. RESULTS: Of the 690 patients with Celect filters placed at our institution, 265 underwent CT for various reasons. The mean (SD) interval between filter placement and last CT was 167.8±264.8 days (median, 56 days; range, 0-1592 days). Penetration of primary leg was observed in 39% (95% CI, 29-51%) of patients within 30 days and 80% (95% CI, 70-87%) of patients within 90 days after placement. The mean number of penetrated legs per patient was 1.8 at 30 days and 2.1 at 90 days after placement. Penetration into adjacent organs occurred in 35 of 265 (13.2%) filters (in 45 IVC filter limbs); penetration into two structures occurred with 10 filters. The sites involved were the duodenum (n=22), aorta (n=9), psoas muscle (n=4), vertebral body (n=3), pancreas (n=2), adrenal gland (n=1), liver (n=1), right kidney (n=1), lymph node (n=1), and diaphragm (n=1). One patient presented with abdominal pain related to penetration. CONCLUSION: This study confirms a high penetration rate for Celect IVC filters and shows that CT can characterize the extent of leg penetration. Most cases of penetration were asymptomatic, but the likelihood of penetration increased over time.

Prevalence of incidental narrowing of the superior segment of the internal jugular vein in patients without multiple sclerosis.

PURPOSE: Internal jugular vein (IJV) narrowing superiorly is likely relatively frequent. IJV narrowing has been proposed as a potential pathophysiologic component for multiple sclerosis (MS). Our purpose was to investigate the prevalence of incidental superior IJV narrowing in patients imaged with neck computed tomography angiography (CTA) for reasons unrelated to IJV pathology or MS. METHODS: We retrospectively identified 164 consecutive adult patients who had undergone neck CTA in which at least one IJV superior segment was opacified (158 right, 155 left IJVs). At the narrowest point of the upper IJV, each IJV was assessed for dominance, graded (shape and narrowing), measured (diameter and area), and located (axially and craniocaudally). Associations were analyzed using Spearman rank correlations (p < 0.05 significant). Medical records were reviewed for MS. RESULTS: Among 164 patients, at least one IJV was: absent/pinpoint in 15 % (25/164), occluded/nearly occluded in 26 % (43/164). Shape, narrowing, and the three measurements all correlated with each other (all p < 0.01). Lateral location with respect to C1 transverse foramen correlated with subjectively and objectively smaller IJVs (p < 0.01). The most common craniocaudal location was at the C1 transverse process (79 % (125/158) of right and 81 % (126/155) of left IJVs). No patient had a diagnosis of MS. CONCLUSIONS: The appearance of the superior IJV is variable, with an occlusive/near-occlusive appearance present in approximately one-quarter of patients without known MS undergoing CTA. Radiologists should be aware of and cautious to report or ascribe clinical significance to this frequent anatomic variant.

Role of CT in the assessment of muscular venous branch invasion in patients with renal cell carcinoma.

OBJECTIVE: The purpose of this article is to determine whether the relationship between a renal cell carcinoma and the renal sinus fat on contrast-enhanced CT could predict muscular venous branch invasion and the type of surgery needed. MATERIALS AND METHODS: A total of 115 consecutive patients underwent pre-operative contrast-enhanced CT between August 2011 and December 2011. Without access to histopathologic information, on nephrographic phase contrast-enhanced CT images, two radiologists independently determined whether the renal tumor was in contact with the renal sinus fat or separated from the renal sinus fat. Interreader agreements and performance characteristics of imaging tests were calculated, and histopathologic analysis served as the standard of reference. RESULTS: Histopathologic analysis identified 115 renal tumors, 90% (103/115) of which were renal cell carcinomas. Thirty-nine percent (31/80) of renal cell carcinomas that abutted the renal sinus fat on CT displayed muscular venous branch invasion on histopathologic analysis. Patients with renal cell carcinomas separated from the renal sinus fat were more likely to undergo partial nephrectomies (96% [22/23]; p = 0.013). Sensitivity and specificity for the identification of muscular venous branch invasion on CT were 94% (95% CI, 80-99%) and 30% (20-42%), respectively. Interreader agreement of visual assessment was excellent (κ = 0.87; 95% CI, 0.81-0.92). CONCLUSION: If a renal cell carcinoma was separated from the renal sinus fat on CT, the likelihood of muscular venous branch invasion being identified by histopathologic analysis was significantly decreased, and the patient was more likely to undergo a partial nephrectomy.

Utility of the analysis of intracranial venous sinuses using preoperative computed tomography venography for safe occipital screw insertion.

STUDY DESIGN: Prospective descriptive study. OBJECTIVE: To verify the feasibility and utility of evaluating venous sinuses (VSs) using computed tomography venography (CTV) concomitant with preoperative CT angiography (CTA) for safe occipital screw fixation. SUMMARY OF BACKGROUND DATA: Preoperative evaluation of the vertebral artery by CTA is indispensable in occipitocervical spinal instrumentation surgery. Despite accumulating evidence showing the potential of CTV, no studies have reported the usefulness of concomitant use of CTV and CTA before placement of occipital plate-screw constructs. METHODS: We analyzed 30 consecutive patients who underwent CTV simultaneously with CTA. First, we investigated VS anatomy in individual cases and classified the continuity patterns of relevant VSs. Subsequently, we evaluated the probable risk zones for VS injury, from the viewpoint of occipital screw insertion. RESULTS: VSs can be clearly visualized using CTV simultaneously with CTA examination without significant increase of radiation exposure or extra workload for radiographical technicians. VS continuity was classified into 4 categories: the confluence type (n = 9), bifurcation type (n = 8), transverse type (n = 11), and others (n = 2). The confluence of sinuses and their relevant VSs were greatly variable between individuals, and occasionally, some cases with high-risk morphology for VS injury in occipital screw placement were observed. CONCLUSION: Our findings indicate that there is no universal position for safe insertion of occipital screws that is applicable to all individuals. It is risky to determine optimal screw placement, only on the basis of traditional cadaveric information such as occipital bone thickness and several external bony landmarks. Spine surgeons must recognize that VS injury may occasionally lead to life-threatening complications. The detailed information on VSs obtained by preoperative CTV examination combined with CTA in individual cases can be useful in preoperative planning and can contribute greatly to the improvement of surgical safety. LEVEL OF EVIDENCE: 2.

Axillary vein puncture without contrast venography for pacemaker and defibrillator leads implantation.

BACKGROUND: Axillary vein puncture has been demonstrated to be an effective method for pacemaker and defibrillator leads implantation, without the complications encountered with the standard intrathoracic approach. OBJECTIVE: Different techniques have been adopted for the cannulation of the axillary vein. We report our experience using the outer edge of the first rib below the inferior border of the clavicle as fluoroscopic landmark. METHOD: A subcutaneous pocket is created 1-cm medially and parallel to the delto-pectoral groove and 2 cm below the clavicle. An 18-gauge needle from the upper border of the pocket is directed perpendicularly to the outer edge of the first rib just below the inferior border of the clavicle. If the vein is not entered, the needle is withdrawn and the puncture is repeated with slight variations of needle direction for a maximum of four to five times, then contrast-guided vein puncture is performed. Upon successful vein puncture, a guidewire is inserted and positioned in the superior vena cava. The remainder of the implantation is carried out in a routine manner. RESULTS: The axillary vein was successfully cannulated without venography in 172 of 182 consecutive patients (94.5%); the vein could not be found in 10 patients (5.5%): in these patients the vein was successfully cannulated after venography performance. No pneumothorax, hemothorax, or brachial plexus injury occurred. CONCLUSIONS: Our approach of axillary venipunture using fluoroscopic landmark, without contrast venography, is simple, safe, and effective.

Venous spasm during contrast-guided axillary vein puncture for pacemaker or defibrillator lead implantation.

AIMS: Contrast-guided axillary vein puncture is commonly used for pacemaker or defibrillator lead implantation. Venous spasm during contrast-guided axillary vein puncture has been reported rarely. We investigated the incidence of venous spasm during contrast-guided axillary vein puncture and the impact of venous spasm on axillary vein puncture. METHODS AND RESULTS: Seventy-four consecutive patients referred for contrast-guided axillary vein puncture for pacemaker or defibrillator implantation were included in the study. The puncture was guided by fluoroscopy and the venogram of axillary vein. After the success of puncture, the venography was taken again. When the puncture could not be successful up to 3 min, the second venography was taken and the puncture was guided by the second venogram. The degree of venous spasm was evaluated by the reduction in the lumen calibre of the axillary vein after puncture. Mild venous spasm and severe venous spasm were defined as a reduction in the lumen calibre of 50-90 and ≥ 90%, respectively. The success rate of axillary vein puncture within 3 min was 87.8%, and the total success rate was 95.9%. Mild venous spasm occurred in 22 patients (29.7%) and severe venous spasm occurred in 6 patients (8.1%). Severe venous spasm occurred in all the three patients with a failed puncture. Severe venous spasm was independently negatively correlated with both success rate within 3 min and total success rate. CONCLUSION: Venous spasm is not a rare phenomenon during the contrast-guided puncture of axillary vein and it has an important negative impact on the puncture.

Incidence of extrinsic compression of the internal jugular vein in unselected patients undergoing CT angiography.

BACKGROUND AND PURPOSE: Little is known about how commonly the internal jugular vein is compressed by extrinsic structures in the upper neck. The purpose of this paper was to identify the frequency and cause of external compression of the superior segment of the internal jugular vein. MATERIALS AND METHODS: Retrospective review of CT angiograms of the neck was performed in 108 consecutive patients. Axial source images were evaluated for moderate (>50%) or severe (>80%) stenosis of the internal jugular vein on the basis of external compression. The cause of extrinsic compression was also recorded. In cases with stenosis, the presence of ipsilateral isoattenuated collateral veins was recorded and considered representative of collateral flow. RESULTS: Moderate stenosis was seen in 33.3% of right and 25.9% of left internal jugular veins. Severe stenosis was seen in 24.1% of right and 18.5% of left internal jugular veins. The most common causes of extrinsic compression included the styloid process and the posterior belly of the digastric muscle. In patients with severe internal jugular vein stenosis, 53.8% of right sides and 55% of left sides had associated condylar collaterals. CONCLUSIONS: Extrinsic compression of the superior segment of the internal jugular vein is a common finding in unselected patients, often caused by the styloid process or the posterior belly of the digastric muscle. Presence of severe stenosis is not universally associated with collateral formation.

Diagnosis of right-sided varicocele: a retrospective comparative study between clinical examination, Doppler findings, US imaging and vascular anatomy at phlebography.

Historically varicocele is diagnosed almost exclusively on the left side. The introduction of new imaging techniques has allowed the identification and characterization of right varicocele. This study aims to compare the diagnostic accuracy of various imaging techniques to data obtained using phlebography in the diagnosis of right varicocele. Patients treated for isolated right varicocele between 1992 and 2010 were retrospectively identified. Data from clinical examination, Doppler-USS, Color-Doppler-USS and Retrograde Phlebography were collected for each patient. 133 out of 4305 patients (3.1%) presented with an isolated right varicocele. 34 of these patients (25.6%) presented with palpable right varicocele. Doppler-USS identified various degrees of type I right venous reflux in 90 patients (67.7%). Phlebography showed venous reflux in all the patients (133), although with variability in terms of internal spermatic vein anatomy. Right varicocele is characterized by predictable anatomic features. Identification and characterization of these features is useful in guiding percutaneous treatment, allowing to optimize radiological display and reducing failure rate.

Evaluation of pulmonary vein variations and anomalies with 64 slice multi detector computed tomography.

UNLABELLED: Pulmonary Veins are one of the major structures of circulation. In the last decade, pulmonary veins have been known to play an important role as the triggering focus of the electrical activity in atrial fibrillation. Primary treatment method of AF is RF ablation of the focus. For the best ablation, the anatomy of PVs should be well established before the procedure. MATERIAL AND METHODS: In our radiology department, 783 patients underwent computed tomography angiography between January 2008 and May 2010. Patients were referred for coronary CTA because of known or suspected coronary artery disease or computed tomography pulmonary angiography (CTPA) because of known or suspect pulmonary embolism. All scanning was performed on Philips Brilliance 64 slice Multidetector CT. The group consisted of 402 male and 381 female patients with the average age of 48 (range 14-89). CT data of patients were retrospectively reviewed to identify the PV anatomy and to determine anatomic variants and anomalies. RESULTS: In the majority of cases, two pulmonary veins drain into the left atrium on each side. Eighteen and eight variations were found in the right and left sides, respectively. Most frequent combined variations were 2R-4L (32.3%) and 4L was the more frequent single variation type (76%). In addition to that one Situs inversus totalis (0.12%), two partial anomalous pulmonary venous returns (0.25%) and one scimitar syndrome (0.12%) were found. CONCLUSION: This study showed that multiple types of variations of PVs can be found with increasing patient number. Therefore, for the successful ablation and surgery without any complications, the anatomy of PVs should be known before the procedure. MDCT is a reliable imaging method for the detailed cross-sectional and 3D anatomy.

A retrospective study of the value of indirect CT venography: a British perspective.

OBJECTIVE: The aim of this study was to establish the value of indirect CT venography (CTV) in clinical practice within the UK. METHODS: 804 combined CT pulmonary angiogram and CTV studies were retrospectively reviewed. CTV was performed 180 s after the injection of contrast using an incremental technique with a 5-mm collimation and a 5-cm interspace between images extending from the iliac crests to the tibial plateaus. RESULTS: 12.9% of studies had isolated pulmonary emboli (PE), 3.0% had both a PE and deep vein thrombosis (DVT) and 1.1% had an isolated DVT. The proportion of positive cases diagnosed by CTV alone was 6.6%. CONCLUSION: In a UK-based practice, the incidence and the proportion of isolated DVT diagnosed by CTV are lower than expected from published data. An analysis of possible causes for this is made within the paper.

No evidence of chronic cerebrospinal venous insufficiency at multiple sclerosis onset.

OBJECTIVE: An impaired cerebrospinal venous drainage, defined as chronic cerebrospinal venous insufficiency (CCSVI), has been recently hypothesized to be the possible cause of multiple sclerosis (MS). We investigated this hypothesis by studying the occurrence of CCSVI in clinically isolated syndromes (CISs) suggestive of MS. METHODS: Fifty consecutive patients presenting with a CIS and evidence of dissemination in space of the inflammatory lesions (ie, possible MS [pMS]) underwent a detailed diagnostic workup, including extracranial and transcranial venous echo-color Doppler sonography (ECDS-TCDS). Those with CCSVI underwent selective venography. Fifty healthy subjects (HCs) age-matched and gender-matched with pMS patients (HC1); 60 patients with transient global amnesia (TGA); and 60 healthy subjects age-matched and gender-matched with TGA patients (HC2) constituted the control groups and underwent ECDS-TCDS. RESULTS: Mean age of pMS patients was 33.0 ± 8.5 years (range, 14-50); 35 (70%) were female (female:male ratio, 2.3). TCDS was normal in all pMS patients. One or more abnormal ECDS findings were observed in 26 of 50 (52.0%) pMS patients, in 35 of 110 (31·8%) HCs (HC1+HC2), and in 41 of 60 (68.3%) TGA patients. Eight (16%) pMS patients fulfilled the diagnosis of CCSVI. Selective phlebography performed in 7 of these patients (1 denied consent) did not show venous anomalies. INTERPRETATION: Our findings do not support a cause-effect relationship between CCSVI and pMS. Further studies are warranted to clarify whether CCSVI is associated with later disease stages and characterizes the progressive forms of MS.

Prevalence of extracranial venous abnormalities: results from a sample of 586 multiple sclerosis patients.

The aim of this study was to assess the prevalence of chronic cerebrospinal venous insufficiency in an unselected cohort of multiple sclerosis (MS) patients. A total of 586 patients with clinically defined MS underwent catheter venography of the internal jugular veins, brachiocephalic veins and azygos vein. The following findings were regarded as pathologic: no outflow, slowed outflow, reversal of flow direction, prestenotic dilation accompanied by impaired outflow, outflow through collaterals, intraluminal structures obstructing the vein, hypoplasia, agenesia or significant narrowing of the vein. Venous abnormalities were found in 563 patients (96.1%). Lesions in one vein were found in 43.5%, in two veins in 49.5%, and in three veins in 3.1% of patients. Venous pathologies in the right internal jugular vein were found in 64.0% of patients, in the left internal jugular vein in 81.7%, in the left brachiocephalic vein in 1.0%, and in the azygos vein in 4.9%. Venous pathologies were found to be highly associated with MS, yet the clinical relevance of this phenomenon remains to be established.

Central adjudication of venous ultrasound in VTE screening trials: reasons for failure.

BACKGROUND: The accuracy of screening ultrasound for venous thrombosis in asymptomatic patients is still a matter of debate. The VENUS study evaluated the accuracy of centrally adjudicated venous ultrasound against venography in patients after major orthopedic surgery and found the sensitivity of ultrasound to be poor for both proximal and distal deep vein thrombus (DVT). OBJECTIVES: To evaluate whether thrombus characteristics such as location or size influence the diagnostic performance of centrally adjudicated venous ultrasound. METHODS: All false negative sonograms of the VENUS study were re-evaluated against the corresponding venograms. Discrepancies were categorized into types of diagnostic failures. Within these categories, thrombus characteristics such as location, length or size of thrombus were evaluated. RESULTS: One hundred and twelve pairs of discrepant ultrasound and venography documents were compared with 28 pairs with concordant results. Discrepancies were caused by local documentation failure (37.5%), failure of the ultrasound method (43.7%) and failure of the central adjudication process (18.7%). The overall size of thrombi was small, which caused about 40% of all sonographic failures with a detection threshold of five Marder points, a thrombus length of 9.5 cm and a number of 3.5 pathological compression manoeuvres. Proximal or distal location of DVT did not affect thrombus detection. CONCLUSION: If centrally adjudicated ultrasound is to be used in future VTE screening trials, training of local sonographers and central adjudicators needs to be intensified, because asymptomatic DVTs seem to be small and ultrasound sensitivity depends on the number of pathological compression manoeuvres documented in the ultrasound document. In contrast, distal or proximal thrombus location itself does not influence sensitivity.