The Fluctuating Natural Course of CCSVI in MS Patients and Controls,a Prospective Follow-Up

Objectives

A new treatable venous disorder, chronic cerebrospinal venous insufficiency (CCSVI), has been proposed in patients with multiple sclerosis. The natural course of CCSVI has not been examined yet. This is crucial given the fact that surgical procedures are increasingly offered to MS patients to treat venous stenosis.

Methods

To document the natural course of venous haemodynamics we performed extra- and transcranial echo colour Doppler (ECD) in 52 multiple sclerosis patients and 28 healthy controls (HC) and re-examined this group after a median period of 16 weeks. The reexamination was done being blinded to the initial findings and the patients did not undergo any intervention.

Results

The ECD examination at baseline showed CCSVI in 5 (9.6%) of the 52 multiple sclerosis patients and 0 HC (P = 0.26). At follow-up the diagnosis CCSVI could not be reconfirmed in 3 out of 5 patients at follow-up, while 2 new CCSVI-positive multiple sclerosis patients were detected.

Conclusions

ECD examination shows a fluctuating natural course of the extracranial venous haemodynamics, which makes determination of CCSVI by ECD examination unreliable.     

Risk factors for chronic cerebrospinal venous insufficiency (CCSVI) in a large cohort of volunteers

Background

The role of intra- and extra-cranial venous system impairment in the pathogenesis of various vascular, inflammatory and neurodegenerative neurological disorders, as well as in aging, has not been studied in detail. Nor have risk factors been determined for increased susceptibility of venous pathology in the intra-cranial and extra-cranial veins. The aim of this study was to investigate the association between presence of a newly proposed vascular condition called chronic cerebrospinal venous insufficiency (CCSVI) and environmental factors in a large volunteer control group without known central nervous system pathology.

Methods and Findings

The data were collected in a prospective study from 252 subjects who were screened for medical history as part of the entry criteria and participated in the case-control study of CCSVI prevalence in multiple sclerosis (MS) patients, and then were analyzed post-hoc. All participants underwent physical and Doppler sonography examinations, and were assessed with a structured environmental questionnaire. Fullfilment of ≥2 positive venous hemodynamic (VH) criteria on Doppler sonography was considered indicative of CCSVI diagnosis. Risk and protective factors associated with CCSVI were analyzed using logistic regression analysis. Seventy (27.8%) subjects presented with CCSVI diagnosis and 153 (60.7%) presented with one or more VH criteria. The presence of heart disease (p = .001), especially heart murmurs (p = .007), a history of infectious mononucleosis (p = .002), and irritable bowel syndrome (p = .005) were associated with more frequent CCSVI diagnosis. Current or previous smoking (p = .029) showed a trend for association with more frequent CCSVI diagnosis, while use of dietary supplements (p = .018) showed a trend for association with less frequent CCSVI diagnosis.

Conclusions

Risk factors for CCSVI differ from established risk factors for peripheral venous diseases. Vascular, infectious and inflammatory factors were associated with higher CCSVI frequency.     

Multiple Sclerosis and CCSVI: A Population-Based Case Control Study

Background

Chronic cerebrospinal venous insufficiency (CCSVI) has been associated to multiple sclerosis (MS).

Objective

To evaluate the possible association between CCSVI and MS, using a population-based control design.

Methods

A random cohort of 148 incident MS patients were enrolled in the study. We have also studied 20 patients with clinically isolated syndrome (CIS), 40 patients with other neurological diseases (OND), and 172 healthy controls. Transcranial (TCC) and Echo Color Doppler (ECD) were carried out in 380 subjects. A subject was considered CCSVI positive if ≥2 venous hemodynamic criteria were fulfilled.

Results

CCSVI was present in 28 (18.9%) of the MS patients, in 2 (10%) of CIS patients, in 11 (6.4%) of the controls, and in 2 (5%) of the OND patients. A significant association between MS and CCSVI was found with an odds ratio of 3.41 (95% confidence interval 1.63–7.13; p = 0.001). CCSVI was significantly more frequent among MS subjects with a disease duration longer than 144 months (26.1% versus 12.6% of patients with duration shorter than 144 months; p = 0.03) and among patients with secondary progressive (SP) and primary progressive (PP) forms (30.2% and 29.4, respectively) than in patients with relapsing remitting (RR) MS (14.3%). A stronger association was found considering SP and PP forms (age adjusted OR = 4.7; 95% CI 1.83–12.0, p = 0.001); the association was weaker with the RR patients (age adjusted OR = 2.58; 95%CI 1.12–5.92; p = 0.02) or not significant in CIS group (age adjusted OR = 2.04; 95%CI 0.40–10.3; p = 0.4).

Conclusions

A higher frequency of CCSVI has been found in MS patients; it was more evident in patients with advanced MS, suggesting that CCSVI could be related to MS disability.     

Chronic Cerebrospinal Venous Insufficiency Is Not Associated with Multiple Sclerosis and Its Severity: A Blind-Verified Study

Background

Chronic Cerebrospinal Venous Insufficiency (CCSVI) has been associated with multiple sclerosis (MS) with a risk ranging from as high as two-hundred-fold to a protective effect. However, not all studies were blinded, and the efficacy of blinding was never assessed.

Objective

To evaluate the association of CCSVI with MS in a cross-sectional blinded study and look for any association of CCSVI with the severity of MS.

Methodology/Principal Findings

The Echo-color Doppler examination was carried out in accordance with Zamboni’s five criteria in 68 consecutive MS patients and 68 healthy controls, matched by gender and age (±5 years). Four experienced neurosonologists, blinded to the status of cases and controls, performed the study and were then asked to guess the status (case or control) of each participant. The number of positive CCSVI criteria was similar in the two groups. CCSVI, defined as the presence of two or more criteria, was detected in 21 cases (30.9%) and 23 controls (33.8%), with an OR of 0.9 (95%CL = 0.4–1.8, p = 0.71). The prevalence of CCSVI was related to age in cases (OR increasing from 0.2 to 1.4), but not in controls. CCSVI positive (N = 21) and negative (N = 47) MS patients were similar in clinical type, age at disease onset, disability, and fatigue. Disease duration was longer (16.5±9.8 years) in CCSVI positive than negative patients (11.5±7.4; p = 0.04). The operators correctly guessed 34/68 cases (50%) and 45/68 controls (66%) (p = 0.06), indicating a different success of blinding.

Conclusions/Significance

CCSVI was not associated with MS itself, nor its severity. We cannot rule out the possibility that CCSVI is a consequence of MS or of aging. Blinding of sonographers is a key point in studying CCSVI and its verification should be a requisite of future studies.     

Decreased brain venous vasculature visibility on susceptibility-weighted imaging venography in patients with multiple sclerosis is related to chronic cerebrospinal venous insufficiency

Background

The potential pathogenesis between the presence and severity of chronic cerebrospinal venous insufficiency (CCSVI) and its relation to clinical and imaging outcomes in brain parenchyma of multiple sclerosis (MS) patients has not yet been elucidated. The aim of the study was to investigate the relationship between CCSVI, and altered brain parenchyma venous vasculature visibility (VVV) on susceptibility-weighted imaging (SWI) in patients with MS and in sex- and age-matched healthy controls (HC).

Methods

59 MS patients, 41 relapsing-remitting and 18 secondary-progressive, and 33 HC were imaged on a 3T GE scanner using pre- and post-contrast SWI venography. The presence and severity of CCSVI was determined using extra-cranial and trans-cranial Doppler criteria. Apparent total venous volume (ATVV), venous intracranial fraction (VIF) and average distance-from-vein (DFV) were calculated for various vein mean diameter categories: < .3 mm, .3-.6 mm, .6-.9 mm and > .9 mm.

Results

CCSVI criteria were fulfilled in 79.7% of MS patients and 18.2% of HC (p < .0001). Patients with MS showed decreased overall ATVV, ATVV of veins with a diameter < .3 mm, and increased DFV compared to HC (all p < .0001). Subjects diagnosed with CCSVI had significantly increased DFV (p < .0001), decreased overall ATVV and ATVV of veins with a diameter < .3 mm (p < .003) compared to subjects without CCSVI. The severity of CCSVI was significantly related to decreased VVV in MS (p < .0001) on pre- and post-contrast SWI, but not in HC.

Conclusions

MS patients with higher number of venous stenoses, indicative of CCSVI severity, showed significantly decreased venous vasculature in the brain parenchyma. The pathogenesis of these findings has to be further investigated, but they suggest that reduced metabolism and morphological changes of venous vasculature may be taking place in patients with MS.

     

Chronic cerebrospinal vascular insufficiency is not associated with HLA DRB1*1501 status in multiple sclerosis patients

Background

Chronic cerebrospinal venous insufficiency (CCSVI) was described as a vascular condition characterized by anomalies of veins outside the skull was reported to be associated with multiple sclerosis (MS). The objective was to assess the associations between HLA DRB1*1501 status and the occurrence of CCSVI in MS patients.

Methodology/Principal Findings

This study included 423 of 499 subjects enrolled in the Combined Transcranial and Extracranial Venous Doppler Evaluation (CTEVD) study. The HLA DRB1*1501 status was obtained in 268 MS patients and 155 controls by genotyping rs3135005, a SNP associated with DRB1*1501 status. All subjects underwent a clinical examination and Doppler scan of the head and neck. The frequency of CCSVI was higher (OR = 4.52, p<0.001) in the MS group 56.0% vs. 21.9% in the controls group and also higher in the progressive MS group 69.8% vs. 49.5% in the non-progressive MS group. The 51.9% frequency of HLA DRB1*1501 positivity (HLA⁺) in MS was higher compared (OR = 2.33, p<0.001) to 31.6% to controls. The HLA⁺ frequency in the non-progressive (51.6%) and progressive MS groups (52.3%) was similar. The frequency of HLA⁺ CCSVI⁺ was 40.7% in progressive MS, 27.5% in non-progressive MS and 8.4% in controls. The presence of CCSVI was independent of HLA DRB1*1501 status in MS patients.

Conclusions/Significance

The lack of strong associations of CCSVI with HLA DRB1*1501 suggests that the role of the underlying associations of CCSVI in MS should be interpreted with caution. Further longitudinal studies should determine whether interactions between these factors can contribute to disease progression in MS.     

Positive End-Expiratory Pressure and Variable Ventilation in Lung-Healthy Rats under General Anesthesia

Objectives

Variable ventilation (VV) seems to improve respiratory function in acute lung injury and may be combined with positive end-expiratory pressure (PEEP) in order to protect the lungs even in healthy subjects. We hypothesized that VV in combination with moderate levels of PEEP reduce the deterioration of pulmonary function related to general anesthesia. Hence, we aimed at evaluating the alveolar stability and lung protection of the combination of VV at different PEEP levels.

Design

Randomized experimental study.

Setting

Animal research facility.

Subjects

Forty-nine male Wistar rats (200–270 g).

Interventions

Animals were ventilated during 2 hours with protective low tidal volume (V_T) in volume control ventilation (VCV) or VV and PEEP adjusted at the level of minimum respiratory system elastance (Ers), obtained during a decremental PEEP trial subsequent to a recruitment maneuver, and 2 cmH₂O above or below of this level.

Measurements and Main Results

Ers, gas exchange and hemodynamic variables were measured. Cytokines were determined in lung homogenate and plasma samples and left lung was used for histologic analysis and diffuse alveolar damage scoring. A progressive time-dependent increase in Ers was observed independent on ventilatory mode or PEEP level. Despite of that, the rate of increase of Ers and lung tissue IL-1 beta concentration were significantly lower in VV than in VCV at the level of the PEEP of minimum Ers. A significant increase in lung tissue cytokines (IL-6, IL-1 beta, CINC-1 and TNF-alpha) as well as a ventral to dorsal and cranial to caudal reduction in aeration was observed in all ventilated rats with no significant differences among groups.

Conclusions

VV combined with PEEP adjusted at the level of the PEEP of minimal Ers seemed to better prevent anesthesia-induced atelectasis and might improve lung protection throughout general anesthesia.     

Neuroregeneration in neurodegenerative disorders

Background

Chronic cerebrospinal venous insufficiency (CCSVI) has recently been reported to be associated with multiple sclerosis (MS). However, its actual prevalence, possible association with specific MS phenotypes, and potential pathophysiological role are debated.

Method

We analysed the clinical data of 710 MS patients attending six centres (five Italian and one Canadian). All were submitted to venous Doppler sonography and diagnosed as having or not having CCSVI according to the criteria of Zamboni et al.

Results

Overall, CCSVI was diagnosed in 86% of the patients, but the frequency varied greatly between the centres. Even greater differences were found when considering singly the five diagnostic criteria proposed by Zamboni et al. Despite these differences, significant associations with clinical data were found, the most striking being age at disease onset (about five years greater in CCSVI-positive patients) and clinical severity (mean EDSS score about one point higher in CCSVI-positive patients). Patients with progressive MS were more likely to have CCSVI than those with relapsing-remitting MS.

Conclusion

The methods for diagnosing CCSVI need to be refined, as the between-centre differences, particularly in single criteria, were excessively high. Despite these discrepancies, the strong associations between CCSVI and MS phenotype suggest that the presence of CCSVI may favour a later development of MS in patients with a lower susceptibility to autoimmune diseases and may increase its severity.     

Assessment of Prosthesis Alignment after Revision Total Knee Arthroplasty Using EOS 2D and 3D Imaging: A Reliability Study

Introduction

A new low-dose X-ray device, called EOS, has been introduced for determining lower-limb alignment in 2D and 3D. Reliability has not yet been assessed when using EOS on lower limbs containing a knee prosthesis. Therefore purpose of this study was to determine intraobserver and interobserver reliability of EOS 2D and 3D knee prosthesis alignment measurements after revision total knee arthroplasty (rTKA).

Methods

Forty anteroposterior and lateral images of 37 rTKA patients were included. Two observers independently performed measurements on these images twice. Varus/valgus angles were measured in 2D (VV2D) and 3D (VV3D). Intraclass correlation coefficients and the Bland and Altman method were used to determine reliability. T-tests were used to test potential differences.

Results

Intraobserver and interobserver reliability were excellent for VV2D and VV3D. No significant difference or bias between the first and second measurements or the two observers was found. A significant mean and absolute difference of respectively 1.00° and 1.61° existed between 2D and 3D measurements.

Conclusions

EOS provides reliable varus/valgus measurements in 2D and 3D for the alignment of the knee joint with a knee prosthesis. However, significant differences exist between varus/valgus measurements in 2D and 3D.     

Initial Imaging Analysis of Budd-Chiari Syndrome in Henan Province of China: Most Cases Have Combined Inferior Vena Cava and Hepatic Veins Involvement

Aim

To evaluate the type of venous involvement in Chinese Budd-Chiari syndrome (BCS) patients and the relative diagnostic accuracy of the different imaging modalities.

Methods

Using digital subtraction angiography (DSA) as a reference standard, color Doppler ultrasound (CDUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA) were performed on 338 patients with BCS. We analyzed the course of the main and any accessory hepatic veins (HVs) and the inferior vena cava (IVC) to assess the etiology of obstructed segments and diagnostic accuracy of CDUS, CTA and MRA.

Results

Among the 338 cases, there were 8 cases (2.4%) of isolated IVC membranous obstruction, 45 cases (13.3%) of isolated HV occlusion, and 285 cases (84.3%) with both IVC membranous obstruction and HV occlusion. Comparing with DSA, CDUS, CTA had a diagnostic accuracy of 89.3% and 80.2% in detecting BCS, and 83.4% of cases correctly correlated by MRA.

Conclusion

In Henan Province, most patients with BCS have complex lesions combining IVC and HV involvement. The combination of CDUS and CTA or MRI is useful for diagnosis of BCS and guiding therapy.     

Autoantibodies and Sjogren’s Syndrome in Multiple Sclerosis,a Reappraisal

Background

Rheumatologic diseases may cause neurologic disorders that mimic multiple sclerosis (MS). A panel of serum autoantibodies is often obtained as part of the evaluation of patients suspected of having MS.

Objectives

To determine, in light of recently revised diagnostic criteria for MS, neuromyelitis optica, and Sjogren’s Syndrome, if testing for autoantibodies in patients with a confirmed diagnosis of MS would reveal a frequency or demonstrate a clinical utility divergent from previous reports or lead to identification of undiagnosed cases of Sjogren’s Syndrome.

Methods

Convenience sample cross-sectional study of MS patients recruited from the OHSU Multiple Sclerosis Center.

Results

Autoantibodies were detected in 38% (35/91) of patients with MS and were not significantly associated with disease characteristics or severity. While four patients had SSA antibodies, none met diagnostic criteria for Sjogren’s Syndrome.

Conclusions

Rheumatologic autoantibodies are frequently found in MS patients and are not associated with disease severity or systemic rheumatologic disease. Our demonstration of the low specificity of these autoantibodies suggests that the diagnostic utility and cost-effectiveness of testing is not supported when there is strong clinical suspicion of MS and low clinical suspicion of rheumatologic disease.     

Ultrasonographic Evaluation of Cerebral Arterial and Venous Haemodynamics in Multiple Sclerosis: A Case-Control Study

Objective

Although recent studies excluded an association between Chronic Cerebrospinal Venous Insufficiency and Multiple Sclerosis (MS), controversial results account for some cerebrovascular haemodynamic impairment suggesting a dysfunction of cerebral autoregulation mechanisms. The aim of this cross-sectional, case-control study is to evaluate cerebral arterial inflow and venous outflow by means of a non-invasive ultrasound procedure in Relapsing Remitting (RR), Primary Progressive (PP) Multiple Sclerosis and age and sex-matched controls subjects.

Material and Methods

All subjects underwent a complete extra-intracranial arterial and venous ultrasound assessment with a color-coded duplex sonography scanner and a transcranial doppler equipment, in both supine and sitting position by means of a tilting chair. Basal arterial and venous morphology and flow velocities, postural changes in mean flow velocities (MFV) of middle cerebral arteries (MCA), differences between cerebral venous outflow (CVF) in clinostatism and in the seated position (ΔCVF) and non-invasive cerebral perfusion pressure (CPP) were evaluated.

Results

85 RR-MS, 83 PP-MS and 82 healthy controls were included. ΔCVF was negative in 45/85 (52.9%) RR-MS, 63/83 (75.9%) PP-MS (p = 0.01) and 11/82 (13.4%) controls (p<0.001), while MFVs on both MCAs in sitting position were significantly reduced in RR-MS and PP-MS patients than in control, particularly in EDSS≥5 subgroup (respectively, 42/50, 84% vs. 66/131, 50.3%, p<0.01 and 48.3±2 cm/s vs. 54.6±3 cm/s, p = 0.01). No significant differences in CPP were observed within and between groups.

Conclusions

The quantitative evaluation of cerebral blood flow (CBF) and CVF and their postural dependency may be related to a dysfunction of autonomic nervous system that seems to characterize more disabled MS patients. It''s not clear whether the altered postural control of arterial inflow and venous outflow is a specific MS condition or simply an “epiphenomenon” of neurodegenerative events.     

Development of a middle cerebral artery occlusion model in the nonhuman primate and a safety study of i.v. infusion of human mesenchymal stem cells

Background

Most experimental stroke research is carried out in rodents, but given differences between rodents and human, nonhuman primate (NHP) models may provide a valuable tool to study therapeutic interventions. The authors developed a surgical method for transient occlusion of the M1 branch of middle cerebral artery (MCA) in the African green monkey to evaluate safety aspects of intravenous infusion of mesenchymal stem cells (hMSCs) derived from human bone marrow.

Methods

The left Sylvian fissure was exposed by a small fronto-temporal craniotomy. The M1 branch of the MCA was exposed by microsurgical dissection and clipped for 2 to 4 hours. Neurological examinations and magnetic resonance imaging (MRI) were carried out at regular post-operative course. hMSCs were infused 1 hour after reperfusion (clip release) in the 3-hour occlusion model.

Results

During M1 occlusion, two patterns of changes were observed in the lateral hemisphere surface. One pattern (Pattern 1) was darkening of venous blood, small vessel collapse, and blood pooling with no venous return in cortical veins. Animals with these three features had severe and lasting hemiplegia and MRI demonstrated extensive MCA territory infarction. Animals in the second pattern (Pattern 2) displayed darkening of venous blood, small vessel collapse, and reduced but incompletely occluded venous flow and the functional deficit was much less severe and MRI indicated smaller infarction areas in brain. The severe group (Pattern 1) likely had less extensive collateral circulation than the less severe group (Pattern 2) where venous pooling of blood was not observed. The hMSC infused animals showed a trend for greater functional improvement that was not statistically significant in the acute phase and no additive negative effects.

Conclusions

These results indicate inter-animal variability of collateral circulation after complete M1 occlusion and that hMSC infusion is safe in the developed NHP stroke model.     

Tumefactive Multiple Sclerosis in Taiwan

Background

Multiple sclerosis (MS) is less common in Asia, including Taiwan, and some characteristics of MS in Asians differ from those of Caucasians. Tumefactive brain lesion is even rarer in MS patients.

Objective

To review patients with tumefactive MS and compare them with those in other studies investigating tumefactive demyelinating lesions and our Taiwanese typical MS patients.

Methods

Twelve patients (6.3%) from the 190 MS patients visiting Taipei Veterans General Hospital from 1985 to 2010 were enrolled. They all fulfilled the McDonald or Poser criteria for MS and had at least one brain lesion larger than 2 centimeters with or without a mass effect.

Results

Eleven patients (91.7%) were female and presented tumefactive brain lesions during the first attack. The clinical course of all patients was relapsing-remitting with a second attack within 2 years. Their initial extended disability status score was higher, but the prognosis was better after more than 2 years of follow-up, than in other studies. Moreover, our patients did not have optic or spinal involvement as well as positive neuromyelitis optica immunoglobulin or aquaporin-4 antibody, which is very common in Taiwanese MS patients.

Conclusion

Tumefactive MS is not common in Taiwan. Although the tumefactive demyelinating lesions seem to be terrible initially, their prognosis is relatively more favorable than expected.     

Partial versus Complete Fundoplication for the Correction of Pediatric GERD: A Systematic Review and Meta-Analysis

Background

There is no consensus as to what extent of “wrap” is required in a fundoplication for correction of gastroesophageal reflux disease (GERD).

Objective

To evaluate if a complete (360 degree) or partial fundoplication gives better control of GERD.

Methods

A systematic search of MEDLINE and Scopus identified interventional and observational studies of fundoplication in children. Screening identified those comparing techniques. The primary outcome was recurrence of GERD following surgery. Dysphagia and complications were secondary outcomes of interest. Meta-analysis was performed when appropriate. Study quality was assessed using the Cochrane Risk of Bias Tool.

Results

2289 abstracts were screened, yielding 2 randomized controlled trials (RCTs) and 12 retrospective cohort studies. The RCTs were pooled. There was no difference in surgical success between partial and complete fundoplication, OR 1.33 [0.67,2.66]. In the 12 cohort studies, 3 (25%) used an objective assessment of the surgery, one of which showed improved outcomes with complete fundoplication. Twenty-five different complications were reported; common were dysphagia and gas-bloat syndrome. Overall study quality was poor.

Conclusions

The comparison of partial fundoplication with complete fundoplication warrants further study. The evidence does not demonstrate superiority of one technique. The lack of high quality RCTs and the methodological heterogeneity of observational studies limits a powerful meta-analysis.     

The Use of Biatain Ag in Hard-to-Heal Venous Leg Ulcers: Meta-Analysis of Randomised Controlled Trials

Background

Venous leg ulcers are common, troublesome, and their failure to heal is often related to a heavy bio-burden. Ionized silver has both anti-inflammatory and antimicrobial properties. The ulcer healing properties of the silver releasing foam dressing Biatain Ag has been examined in 4 randomized controlled trials (RCTs).

Aim

To evaluate ulcer healing through a meta-analytic approach after treatment with either Biatain Ag or a non-active dressing.

Patients and Methods

685 subjects with pure or mixed hard-to-heal venous leg ulcers were included in the meta-analysis.

Results

Biatain Ag showed a significant treatment effect (p<0.0001), responder rate (p<0.001), and healing rate (p = 0.002).

Conclusion

The meta-analysis of the 4 RCTs provided statistical significant evidence to support the use of Biatain Ag dressing in treatment of hard-to-heal venous leg ulcers.     

The Accuracy of the New Landmark Using Respiratory Jugular Venodilation and Direct Palpation in Right Internal Jugular Vein Access

Background

Although ultrasonography is recommended in internal jugular vein (IJV) catheterization, the landmark-guided technique should still be considered. The central landmark using the two heads of the sternocleidomastoid muscle is widely used, but it is inaccurate for IJV access. As an alternative landmark, we investigated the accuracy of the new landmark determined by inspection of the respiratory jugular venodilation and direct IJV palpation in right IJV access by ultrasonography.

Methods and Findings

Thirty patients were enrolled. After induction of anesthesia, the central landmark was marked at the cricoid cartilage level (M1) and the alternative landmark determined by inspection of the respiratory jugular venodilation and direct palpation of IJV was also marked at the same level (M2). Using ultrasonography, the location of IJV was identified (M3) and the distance between M1 and M3 as well as between M2 and M3 were measured. The median (interquartile range) distance between the M2 and M3 was 3.5 (2.0–6.0) mm, compared to 17.5 (12.8–21.3) mm between M1 and M3. (P<0.001) The dispersion of distances between M2 and M3 was significantly smaller than between M1 and M3. (P<0.001) The visibility of respiratory jugular venodilation was associated with CVP more than 4 mmHg. Limitations of the present study are that the inter-observer variability was not investigated and that the visibility of the alternative landmark can be limited to right IJV in adults.

Conclusion

The alternative landmark may allow shorter distance for the right side IJV access than the central landmark and can offer advantages in right IJV catheterization when ultrasound device is unavailable.

Trial Registration

Clinical Research Informational Service KCT0000812     

Quantitative ColourDopplerSonography evaluation of cerebral venous outflow: a comparative study between patients with multiple sclerosis and controls

Background

Internal Jugular Veins (IJVs) are the principle outflow pathway for intracranial blood in clinostatism condition. In the seated position, IJVs collapse, while Vertebral Veins (VVs) increase the venous outflow and partially compensate the venous drainage. Spinal Epidural Veins are an additional drainage pathway in the seated position. Colour- Doppler-Sonography (CDS) examination is able to demonstrate IJVs and VVs outflow in different postural and respiratory conditions. The purpose of this study was to evaluate CDS quantification of the cerebral venous outflow (CVF) in healthy subjects and patients with multiple sclerosis (MS).

Methodology/Principal Findings

In a group of 27 healthy adults (13 females and 14 males; mean age 37.8±11.2 years), and 52 patients with MS (32 females and 20 males; mean age 42.6±12.1 years), CVF has been measured in clinostatism and in the seated position as the sum of the flow in IJVs and VVs. The difference between CVF in clinostatism and CVF in the seated position (ΔCVF) has been correlated with patients'' status (healthy or MS), and a number of clinical variables in MS patients. Statistical analysis was performed by Fisher''s exact test, non-parametric Mann-Whitney U test, ANOVA Kruskal-Wallis test, and correntropy coefficient.The value of ΔCVF was negative in 59.6% of patients with MS and positive in 96.3% of healthy subjects. Negative ΔCVF values were significantly associated with MS (p<0.0001). There was no significant correlation with clinical variables.

Conclusions/Significance

Negative ΔCVF has a hemodynamic significance, since it reflects an increased venous return in the seated position. This seems to be a pathologic condition. In MS patients, a vascular dysregulation resulting from involvement of the autonomous nervous system may be supposed. ΔCVF value should be included in the quantitative CDS evaluation of the cerebral venous drainage, in order to identify cerebral venous return abnormalities.     

A Retrospective Study of Preferable Alternative Route to Right Internal Jugular Vein for Placing Tunneled Dialysis Catheters: Right External Jugular Vein versus Left Internal Jugular Vein

Background

Right internal jugular vein (IJV) is a preferred access route for tunneled (cuffed) dialysis catheters (TDCs), and both right external jugular vein (EJV) and left IJV are alternative routes for patients in case the right IJV isn’t available for TDC placement. This retrospective study aimed to determine if a disparity exists between the two alternative routes in hemodialysis patients in terms of outcomes of TDCs.

Methods

49 hemodialysis patients who required TDCs through right EJV (n = 21) or left IJV (n = 28) as long-term vascular access were included in this study. The primary end point was cumulative catheter patency. Secondary end points include primary catheter patency, proportion of patients that never required urokinase and incidence of catheter-related bloodstream infections (CRBSI).

Results

A total of 20,870 catheter-days were evaluated and the median was 384 (interquartile range, 262–605) catheter-days. Fewer catheters were removed in the right EJV group than in the left IJV group (P = 0.007). Mean cumulative catheter patency was higher in the right EJV group compared with the left IJV group (P = 0.031). There was no significant difference between the two groups in the incidence of CRBSI, primary catheter patency or proportion of patients that never required urokinase use. Total indwell time of antecedent catheters was identified as an independent risk factor for cumulative catheter patency by Cox regression hazards test with an HR of 2.212 (95% CI, 1.363–3.588; p = 0.001).

Conclusions

Right EJV might be superior to left IJV as an alternative insertion route for TDC placement in hemodialysis patients whose right IJVs are unavailable.     

Acute Variations in Retinal Vascular Oxygen Content in a Rabbit Model of Retinal Venous Occlusion

Purpose

To study the variation in intravascular oxygen saturation (oximetry) during an acute retinal vein occlusion (RVO) using hyperspectral computed tomographic spectroscopy based oximetry measurements.

Methods

Thirty rabbits were dilated and anesthetized for experiments. Baseline oximetry measurements were made using a custom-made hyperspectral computed tomographic imaging spectrometer coupled to a fundus camera. RVO were induced using argon green laser following an intravenous injection of Rose Bengal. RVO induction was confirmed by fluorescein angiography. Retinal oximetry measurements were repeated in arterial and venous branches one hour after RVO induction and up to 4 weeks afterwards. Comparison of retinal oximetry before and after vein occlusion was made using the Student T-test.

Results

One hour after RVO induction, we observed statistically significant reductions in the intravascular oxygen saturation in temporal retinal arteries (85.1±6.1% vs. 80.6±6.6%; p<0.0001) and veins (71.4±5.5% vs. 64.0±4.7%; p<0.0001). This decrease was reversible in animals that spontaneously recannulated the vein occlusion. There were no statistically significant differences in oxygen saturation in the nasal control arteries and veins before and after temporal vein RVO induction.

Conclusions

We demonstrate, for the first time, acute changes in the intravascular oxygen content of retinal vessels 1 hour after RVO. These changes are reversible upon spontaneous recannulation of retinal vessels. This study demonstrates that hyperspectral computer tomographic spectroscopy based oximetry can detect physiological variations in intravascular retinal oxygen saturation. The study also provides the first qualitative and quantitative evidence of the variation in retinal vascular oxygen content directly attributable to an acute retinal vein occlusion.