Venous Flow Patterns Research Articles

Altered Pulmonary Venous Flow Pattern in Young Adults with Atrial Septal Defect

Introduction: Atrial septal defect (ASD) is a common congenital heart disease and causes left-to-right shunting and significant right ventricular (RV) volume overload. The goal of this study was to evaluate the influence of these hemodynamic changes on pulmonary venous flow pattern in young adults. Methods: Complete echocardiographic examination was performed in a group of 40 young adults (aged < 40 years) who had secundum type ASD and was compared to 40 age-matched individuals in control group who had no cardiac abnormality. Systolic and diastolic flow velocities in pulmonary veins (PV), superior vena cava (SVC), inferior vena cava (IVC) and RV functional parameters were recorded and evaluated. Results: As opposed to healthy young individuals who showed distinct S and D waves with diastolic predominance in pulmonary vein Doppler, in patients with ASD a continuous flow with increased systolic peak that began in systole and continued to the late diastole was observed. The RV systolic function increased compared to the control group. Conclusions: In patients with ASD, the pattern of pulmonary veins flow transforms into a single continuous antegrade wave with systolic dominance due to persistent shunting of left atrial blood in to right heart chambers as well as increased RV pump function on pulmonary vein (by means of ASD), SVC and IVC, and could be used as a screening method for the presence of secundum type ASDs in young adults.

Clinical Implications of Intrarenal Hemodynamic Evaluation by Doppler Ultrasonography in Heart Failure

ObjectivesThis study clarified the characteristics of intrarenal Doppler ultrasonography (IRD) profiles and their prognostic implications in heart failure (HF). BackgroundIRD can assess intrarenal hemodynamics. MethodsInitially, 224 patients with HF were prospectively enrolled; 151 inpatients were enrolled during hospitalization for HF, and 73 were outpatients in our institution. In IRD profiles of interlobar vessels, the arterial resistance index (RI), venous impedance index (VII), and intrarenal venous flow (IRVF) pattern were assessed. Patients were followed to evaluate the associations with 1-year prognosis. Primary endpoints included death from cardiovascular disease and unplanned hospitalization for HF. ResultsFinally, 217 patients with adequate IRD images were enrolled. IRD profiles were associated with conventional risk factors for HF. In particular, IRVF was associated with mean right atrial pressure (RAP); 3 IRVF patterns were stratified by RAP (in a continuous pattern: 5.4 ± 2.5; in a biphasic pattern: 9.5 ± 3.5; and in a monophasic pattern: 14.9 ± 4.3 mm Hg; p < 0.001). In addition, the monophasic IRVF pattern had a poorer prognosis than the other patterns (log rank p < 0.001), and prognosis was poorer for the biphasic pattern than for the continuous flow pattern (log rank p = 0.01). Multivariate Cox proportional hazard model analysis revealed that IRVF patterns were associated with the endpoints, independent of other HF risk factors. ConclusionsIRVF patterns, rather than RI, depended on RAP, suggesting a correlation with renal congestion. In addition, IRVF patterns strongly correlated with clinical outcomes independent of RAP and other risk factors and might provide additional information to stratify vulnerable HF patients.

Normal Diaphragmatic and Rib Cage Breathing: Effects on Venous Return Patterns in Monitored Human Subjects

Objective: To measure the natural prevalence of diaphragmatic (DB) and rib cage breathing (RCB) and their respective effects on venous return in human subjects. Methods: Sixteen subjects (9 men, 4 women, and 3 boys, aged 10 to 83) were monitored for breathing patterns with stretch transducers on the upper chest, the mid chest, and the abdomen at the umbilicus. Monitoring for venous flow patterns was carried out with infrared transducers on the forehead, sampling superior vena cava (SVC) volume, and with leg electrodes, sampling leg blood volume (LBV) by electrical impedance. Recordings were made during 3 minute periods of sitting and standing after knee bending exercise. Results: DB, indicated by inward movement of the mid chest with breathing, accounted for 0 - 46% of breathing activity in all positions (One subject had no DB) this breathing pattern correlated with an overflow of venous volume into the SVC. RCB, consisting of upper chest expansion, mid chest constriction, and inward abdominal movement at the umbilicus - accounted for 9 - 37% of breathing activity. This breathing pattern correlated with extraction of LBV, superimposed on an underlying sinusoidal fluctuation of LBV. Conclusions: DB and RCB are normal, prevalent breathing patterns augmenting venous return to the heart. SVC backflow and rhythmic LBV were observed for the first time.

Emergency Cesarean Section in Case of Aneurysm of the Muscular Intraventricular Septum with Neonatal Follow-up - A Case Report and Review of the Literature

Abstract We present the case of aneurysm of the muscular intraventricular septum with accompanying cardiomegaly and abnormal venous flow patterns requiring emergency cesarean section and specialized neonatal treatment. At the age of 8 months our patient has no clinical symptoms with a 6 mm scar in intraventricular muscular septum..

Intraoperative Micro-Doppler in Cerebral Arteriovenous Malformations.

Intraoperative micro-Doppler (IOMD), intraoperative digital substraction angiography (DSA), and microscope-integrated indocyanine green angiography are methods that guide neurosurgical resection of arteriovenous malformations (AVMs) in the brain and minimize the trauma of healthy tissue. In this study we emphasize the use of IOMD in AVM surgery, analyzing the advantages and the limitations of this method. Patients and A total of 32 patients were diagnosed with an AVM. Supplying arteries and draining veins were analyzed regarding hemodynamic profiles, flow velocities, pulsatility index (PI), and resistance index (RI). Venous drainages were accompanied by arterial blood flow disturbances that showed typical characteristics in all cases. We set an angle of 60 degrees between the examined vessel and the probe to achieve a more reliable and comparable measurement. Postoperative DSA was performed in all patients. Supplying arterial blood vessels of AVMs could be identified by their characteristic blood flow profiles with PI < 0.7 and RI < 0.55. Drainage veins in all 32 cases showed normalized venous flow patterns without arterial flow turbulences at the end of the surgical procedure. Postoperative DSA revealed a residual AVM in one patient. IOMD constitutes a safe, accurate, and low-cost imaging modality for evaluating blood flow velocities and for optimal stepwise AVM elimination without unnecessary sacrifice of veins. PI and RI are reliable parameters in diagnosing cerebrovascular malformations, but systolic and diastolic flow velocities may vary to a greater extent. This phenomenon has never been elucidated previously and therefore needs to be emphasized when using this technique intraoperatively.

Sinistral portal hypertension after pancreaticoduodenectomy with splenic vein ligation.

Splenic vein ligation may result in sinistral (left-sided) portal hypertension and gastrointestinal haemorrhage. The aim of this study was to analyse the pathogenesis of sinistral portal hypertension following splenic vein ligation in pancreaticoduodenectomy. Patients who underwent pancreaticoduodenectomy for pancreatic cancer between January 2005 and December 2012 were included in this retrospective study. The venous flow pattern from the spleen and splenic hypertrophy were examined after surgery. Of 103 patients who underwent pancreaticoduodenectomy with portal vein resection, 43 had splenic vein ligation. There were two predominant venous flow patterns from the spleen. In the varicose route (27 patients), flow from the spleen passed to colonic varices and/or other varicose veins. In the non-varicose route, flow from the spleen passed through a splenocolonic collateral (14 patients) or a spontaneous splenorenal shunt (2 patients). The varicose route was associated with significantly greater splenic hypertrophy than the non-varicose route (median splenic hypertrophy ratio 1·52 versus 0·94; P < 0·001). All patients with the varicose route had colonic varices, and none had a right colic marginal vein at the hepatic flexure. Pancreaticoduodenectomy with splenic vein ligation may lead to sinistral portal hypertension. To avoid the development of varices, it is important to preserve the right colic marginal vein. Reconstruction of the splenic vein should be considered if the right colic marginal vein is divided.

Fetal pulmonary venous Doppler flow patterns in hypoplastic left heart syndrome

To discuss the value of fetal pulmonary venous Doppler flow patterns in hypoplastic left heart syndrome (HLHS). Forty-six HLHS and 180 normal singleton fetuses at 24+0 to 37+6 weeks of gestation were enrolled in this study. The blood flow of pulmonary vein (PV) was detected by color Doppler ultrasound. The systolic wave of ventricle (S-wave), diastolic wave of ventricle (D-wave), atrial contraction wave (A-wave) and S/D ratio of PV were measured. The statistical difference in the above parameters between HLHS and normal fetuses was compared. The diagnosis was also confirmed by autopsy in still birth or postnatal follow-up when the baby was alive. The PV blood flow in HLHS fetuses had a high possibility of reversed A wave, and the velocity of S wave and S/D ratio were higher than the matched normal controls (P<0.001). There were 3 types of PV blood flow patterns among all fetuses with HLHS. Both the cases with right to left shunt through foramen ovale (FO) and the cases with restricted left to right shunt at FO showed the triphasic patterns of PV with antegrade S wave, D wave and retrograde A wave. However, the latter had a higher velocity of retrograde A wave (P<0.001), lower D wave (P<0.001), and obviously elevated S wave and S/D ratio (P<0.001). The cases with intact interatrial septum showed short and apparent pulsatile back and forth blood flow in the PV, which displayed as absence of D wave. The 3 types of PV blood flow patterns in the fetuses with HLHS reflect the severity of hypertension in the left atrium, which is extremely vital for the prognosis and the perinatal treatment plan.

Developmental venous anomaly in the newborn brain.

Cerebral developmental venous anomaly (DVA) is considered a benign anatomical variant of parenchymal venous drainage; it is the most common vascular malformation seen in the adult brain. Despite its assumed congenital origin, little is known about DVA in the neonatal brain. We report here the first cohort study of 14 neonates with DVA. Fourteen infants (seven preterm) with DVA diagnosed neonatally using cranial ultrasound (cUS) and magnetic resonance imaging (MRI) from three tertiary neonatal units over 14 years are reviewed. DVA was first detected on cUS in 6 and on MRI in 8 of the 14 infants. The cUS appearances of DVA showed a focal fairly uniform area of increased echogenicity, often (86 %) adjacent to the lateral ventricle and located in the frontal lobe (58 %). Blood flow in the dilated collector vein detected by Doppler ultrasound (US) varied between cases (venous flow pattern in ten and arterialized in four). The appearance on conventional MRI was similar to findings in adults. Serial imaging showed a fairly constant appearance to the DVAs in some cases while others varied considerably regarding anatomical extent and flow velocity. This case series underlines that a neonatal diagnosis of DVA is possible with carefully performed cUS and MRI and that DVA tends to be an incidental finding with a diverse spectrum of imaging appearances. Serial imaging suggests that some DVAs undergo dynamic changes during the neonatal period and early infancy; this may contribute to why diagnosis is rare at this age.

Venous Insufficiency Evaluation with Duplex Scanning

Venous duplex scanning can be divided into two different subcategories: (1) scanning to diagnose thrombus and (2) scanning to diagnose incompetence. Venous incompetence testing is used to assess the physiology of the superficial and deep venous systems, making it a much more complex and time-consuming test, primarily because sonographers need to take into consideration the great number of anatomical variations of the superficial venous system, venous flow patterns, as well as physiology. To perform these examinations efficiently and to obtain consistent results, it is imperative to standardize protocols and to break down these examinations into manageable components.

The Disappearing Brain-Sparing Effect in Early-Onset Fetal Growth Restriction Fetuses Revisited

Objective: To evaluate the association between the brain-sparing situation and perinatal outcomes in fetuses with early-onset fetal growth restriction (EO-FGR) with absent or reverse end-diastolic flow in the umbilical artery (UA A/REDF). Methods: We evaluated fetuses with EO-FGR who had patterns of UA A/REDF without abnormal venous Doppler indices. Participants were divided into two groups according to measurements of mid-cerebral artery pulsatility index (MCA PI) just before delivery. Group 1 (n = 45) included those with a brain-sparing effect (BSE) (a MCA PI <5th percentile for the gestational age) and group 2 (n = 14) included those with a disappearing BSE, defined as an MCA PI increase towards normal values after the BSE detected at the initial evaluation. Short-term perinatal outcomes were analyzed. Results: Compared to group 1, group 2 had a significantly low birth weight (p = 0.018) and high rates of extended neonatal intensive care unit hospitalization (p = 0.049 respectively). Conclusion: On the basis of longitudinal measurements of MCA PI, increases after the reduction <5th percentile might be related to poor perinatal outcomes in fetuses with EO-FGR who had UA A/REDF without abnormal venous flow patterns.

Concomitant Analysis of Arterial, Venous, and CSF Flows using Phase-Contrast MRI: A Quantitative Comparison Between MS Patients and Healthy Controls

Venous dysfunction has recently been hypothesized to contribute to the pathophysiology of multiple sclerosis (MS). 2D phase-contrast (PC) magnetic resonance imaging (MRI) is a non-invasive and innocuous technique enabling reliable quantification of cerebrospinal fluid (CSF) and blood flows in the same imaging session. We compared PC-MRI measurements of CSF, arterial and venous flows in MS patients to those from a normative cohort of healthy controls (HC). Nineteen MS patients underwent a standardized MR protocol for cerebral examination on a 3T system including Fast cine PC-MRI sequences with peripheral gating in four acquisition planes. Quantitative data were processed using a homemade software to extract CSF and blood flow regions of interest, animate flows, and calculate cervical and intracranial vascular flow curves during the cardiac cycle (CC). Results were compared with values obtained in 21 HC using multivariate analysis. Venous flow patterns were comparable in both groups without signs of reflux. Arterial flows (P=0.02) and cervical CSF dynamic oscillations (P=0.01) were decreased in MS patients. No significant differences in venous cerebral and cervical outflows were observed between groups, thereby contradicting the recently proposed theory of venous insufficiency. Unexpected decrease in arterial perfusion in MS patients warrants further correlation to volumetric measurements of the brain.

Are hepatic portal venous system components distributed equally in the liver? A multidetector computerized tomography study.

We aimed to evaluate the relationships between the splenic index, right and left hepatic lobe volumes, diameters of splenic vein (SV), superior mesenteric vein (SMV) and the portal vein (PV) by Multidetector Computerized Tomography (MDCT). We also investigated indirect signs of portal venous flow pattern using these parameters. Following their contrast thoracoabdominal and abdominal 64-MDCT examinations, the images of 100 cases (61 males and 39 females) were evaluated retrospectively. For each case, the splenic index, total hepatic volume, left and right hepatic volumes were calculated on the post-contrast portal venous phase (50(th) sec) images. Spearman correlation tests were carried out with the purpose of determining the relationships between the variables. Statistical significance level was set at p<0.005. A statistically significant relation was demonstrated between the diameter of the SMV and right hepatic lobe volume (p<0.0001), and according to Pearson's correlation analysis, a positive correlation of medium strength (r=0.36) was observed. A positive correlation was demonstrated between the diameter of the splenic vein and left hepatic lobe volume (r=0.36). Statistically significant relation between the diameters of the splenic vein and right hepatic lobe was not observed (p=0.62). A strong correlation between the left hepatic lobe volume and the splenic index (r=0.556) was observed. We observed a positive correlation and a significant relation between the diameter of the SMV and the right hepatic lobe, and a relation between the splenic vein and splenic index and both hepatic lobes. We believe that this situation is related to the streamline flow in the portal vein, and as demonstrated in the literature, the flow in the SMV is directed at the right lobe, whereas the splenic vein empties into the liver homogenously. Our study is the first study in the literature performed by multidetector CT, which is a technique that reveals the relations between the streamline flow in the portal vein, the splenic index and the hepatic lobe volumes.

Alterations in Venous Flow Patterns in a Pediatric Patient: Impact of Mechanical Ventilation

Lower extremity venous waveforms are normally phasic with respiration and not pulsatile. The following case study describes abnormal venous spectral Doppler waveforms encountered during a pediatric ultrasound examination. A four-year-old female patient presented to the hospital with acute respiratory distress. The patient was immediately intubated and placed on an oscillating ventilator. A lower extremity venous duplex was ordered to rule out a deep venous thrombosis (DVT) due to the presence of lower extremity swelling and a fever. Thrombus was observed in the left common femoral vein surrounding a central venous catheter. The thrombus extended into the external iliac vein. This thrombus appeared hypoechoic and spongy in nature and was interpreted to be acute. Additionally, pulsatile waveforms were noted bilaterally through both lower extremities. There was no history of congestive heart failure or pulmonary hypertension. Subsequently, the patient was found to have Factor V Leiden. A repeat venous ultrasound was ordered 10 days later at which time the patient was no longer intubated. The venous waveforms in the left leg were now continuous while the right leg displayed normal, phasic waveforms. No venous pulsatility was present in either extremity. Continuous venous Doppler signals are expected in the presence of non-occlusive DVT. This case illustrates the unusual occurrence of pulsatile lower extremity venous Doppler signals. These were the result of respiratory pressure changes due to the oscillating ventilator. It is important to consider the effects of mechanical ventilation on venous blood flow patterns.

Fetal Pulmonary Venous Flow and Restrictive Foramen Ovale in Hypoplastic Left Heart

Hypoplastic left heart (HLH) with intact or restrictive interatrial communication (HLH-IAS/RAS) is associated with high mortality rates. The object was to correlate pulmonary venous (PV) Doppler spectra and direct foramen ovale (FO) assessment with the neonatal need for early atrial septostomy (EAS) and neonatal outcome. We reviewed all prenatal echocardiograms and outcomes of 51 fetuses with HLH and information about the interatrial communication between 1994 - 2011. IAS/RAS was defined as a small/absent interatrial shunt on 2-dimensional imaging. Three PV Doppler spectra were observed: type A: continuous forward flow with a small a wave reversal; type B: continuous forward flow with increased a-wave reversal; type C: brief to-and-fro flow. Three of 51 neonates with type C pulmonary venous flow pattern and suspicion of IAS/RAS on 2-dimensional (2-DE) evaluation required EAS. In one fetus pulmonary venous flow changed from type B to type C spectra throughout gestation. Fetuses with type C spectra showed a 71.4 % survival after 30 days compared to 92.3 % in fetuses with type A spectra. Short term survival after EAS was 33 %. Prenatal PV flow pattern and 2-DE of the FO size help in identifying the fetus at risk for neonatal EAS and patient selection for fetal cardiac intervention. Most late second trimester values will not change over time.

Hepatofugal Portal Venous Flow on Doppler Sonography After Liver Transplantation

The purpose of this study was to categorize hepatofugal portal venous flow on Doppler sonography after liver transplantation and to investigate its clinical importance and presumed causes based on radiologic and pathologic findings. This retrospective study was approved by our Institutional Review Board, and the requirement for informed consent was waived. Examination of our database over 4 years revealed 30 patients in whom Doppler sonography showed hepatofugal portal venous flow during follow-up periods. We investigated its occurrence and clinical features, including radiologic and pathologic findings, and classified the possible causes into 5 types: A, systemic problems; B, gross vascular abnormalities correctable by intervention; C, specific cardiac problems; D, microscopic abnormalities of the graft; and E, miscellaneous. We classified the patterns of hepatofugal portal venous flow into continuous hepatofugal or hepatofugal-dominant to-and-fro flow and hepatopetal-dominant to-and-fro flow, and we investigated the relationship of the presumed causes and flow patterns with the clinical course. The incidence of hepatofugal portal venous flow was 2.38%. The overall mortality rate was 26.67% (95% confidence interval, 11.1%-42.9%): all patients (n = 5) in group A, 1 in group C, and 2 in group D, died. Possible cause type B and a mainly hepatopetal flow pattern were good prognostic factors (P = .031 and .018, respectively). Hepatofugal portal venous flow reflects diverse pathologic conditions after liver transplantation, and its clinical importance also differs depending on the cause.

The Use of Reconstructive Surgery to Improve Quality of Life and Survival in Prenatal Hypoplastic Left Heart Syndrome

Outcomes for hypoplastic left heart syndrome have improved substantially in the era of prenatal diagnosis. Current stage 1 survival rates are in excess of 90% in the absence of risk factors. However, fetuses with an intact atrial septum continue to have poor postnatal survival. Accurate diagnosis of these fetuses with an intact atrial septum relies upon careful assessment of the patent foramen ovale, pulmonary venous Doppler flow patterns and branch pulmonary artery Doppler flow patterns. Prenatal and perinatal interventions, such as the placement of an atrial stent in utero or delivery at a center where a stent may be placed immediately after birth to relieve left atrial hypertension, may improve survival in this particularly high-risk group.

30 VALIDATING THE USEFULNESS OF DOPPLER STUDY OF HEPATIC VEINS IN PREDICTING ESOPHAGEAL VARICES IN CIRRHOTIC PATIENTS

Loss of normal hepatic venous triphasic wave form is a very sensitive non invasive marker for predicting the presence of large esophagial varices with reasonably high positive and negative predictive value. latelet count/splenic diameter ratio, if taken with a cut off of ≤909, can predict the presence of large esophagial varices with reasonably good accuracy. Comparing hepatic venous flow pattern to platelet count splenic diameter ratio,the formor is more strongly associated with the presence of large varices and scores over the latter in terms of negative predictive value. Both are comparable in terms of sensitivity, specificity and positive predictive value. Hepatic venous flow pattern did not have a statistically significant correlation with the incidence of UGI bleed.

Dynamics of Intracranial Venous Flow Patterns in Patients with Idiopathic Intracranial Hypertension

Objective: To examine the dynamics of intracranial venous flow patterns in patients with idiopathic intracranial hypertension (IIH). Methods: Nonrandomized controlled trial analyzing the difference in cerebral perfusion in 13 IIH patients and 12 healthy controls using contrast-enhanced duplex sonography. In patients, an additional 3D gradient echo magnetic resonance venography (MRV) using a new technique was performed to quantify stenosis of the cerebral sinus. The cerebral perfusion parameters, including cerebral transit time (CTT) and time to peak (TTP), were analyzed. Results: IIH patients had a higher BMI (29.3 [95% CI 26.4, 32.2] vs. 23.3 [95% CI 20.7, 25.9], p = 0.003) and an increased prevalence of headache, but all other clinical characteristics were comparable. The CTT did not differ significantly. The TTP was significantly longer in IIH patients compared to controls (8.5 [95% CI 7.6, 9.4] vs. 7.3 s [95% CI 6.3, 8.1], p = 0.04). Twelve of 13 (92%) IIH patients showed stenosis of the cerebral sinus. Conclusions: Our study is the first to report an altered cerebral venous flow in IIH patients compared to controls using a dynamic ultrasonographic technique. A simplified MRV technique confirms the high prevalence and reliable detection of venous stenosis in IIH patients.

Pathophysiology of chronic venous insufficiency in adults with a Fontan circulation (a pre-defined substudy of the CALF investigation)

ObjectivesTo investigate the pathophysiology of chronic venous insufficiency in adults with a Fontan circulation. BackgroundChronic venous insufficiency (CVI) is prevalent in adults with a Fontan circulation, however the underlying pathophysiology has not been identified. We defined the prevalence of venous reflux and obstruction in a Fontan population, identified associated factors, and assessed the hypothesis that venous reflux correlates with clinical CVI in adults with a Fontan circulation. MethodsFifty-one adult Fontan subjects from the Congenital Heart Disease in Adults: Lower Extremity Systemic Venous Health in Fontan Patients (CALF) study, ten control subjects without cardiac disease, and ten comparator subjects with repaired tetralogy of Fallot underwent lower extremity Doppler venous ultrasound. We investigated 10 venous segments in each subject for venous obstruction and reflux. ResultsThe prevalence of venous reflux was significantly greater in the Fontan population compared to healthy controls (51% vs. 10%, p=0.03). Venous flow patterns demonstrated a range of pulsatility and biphasic flow in many subjects. There was no evidence of venous obstruction in any subject. Venous reflux did not correlate with clinical venous insufficiency; 49% of Fontan subjects with observed venous reflux demonstrated no clinical signs of venous disease. Predictors of venous reflux in multivariate analysis were single right ventricle (p=0.03), use of anti-arrhythmic medications (p=0.04), and family history of venous disease (p=0.003). ConclusionsVenous reflux is highly prevalent and venous obstruction is absent in adults with a Fontan circulation. Clinical CVI underestimates pathophysiologic venous insufficiency in adults with a Fontan circulation.

Extra-cranial venous flow in patients with multiple sclerosis

Introduction Recently, a chronic state of impaired venous drainage from the central nervous system, termed chronic cerebrospinal venous insufficiency (CCSVI) was claimed to be a pathologic condition exclusively seen in patients with multiple sclerosis (MS), suggesting that cerebral venous congestion plays a significant role in the pathogenesis of MS. This hypothesis has gained enormous attention among patients and physicians but has been questioned since. Methods Twenty seven patients with MS and 32 healthy controls underwent color extra cranial Doppler exam aimed to detect four parameters of abnormal venous flow: no Doppler-detected flow in the IJV or vertebral veins (VV), reflux in the internal jugular veins (IJVs), venous flow stenosis in the IJVz (cross sectional area < 0.3 cm) or reverted postural control in the IJV. Results Except for one healthy patient, blood flow direction in the IJVs was normal in all subjects. When aiming to detect at least one parameter of abnormal venous flow per subject, two parameters or three parameters no significant difference was found between subjects and controls (p = 0.707, 0.62, 0.849 respectively). Conclusion We found no evidence to suggest that MS patients have excess of CCSVI. In addition we failed to observe a typical venous flow pattern in MS patients. Until carefully designed controlled studies to investigate CCVSI have been completed, invasive and potentially dangerous endovascular procedures as therapy for MS should be discouraged.