Efficacy and safety of implantable vascular support in the treatment of arteriovenous fistula: A single-arm meta-analyses

BACKGROUND AND OBJECTIVES

VasQ (Laminate Medical Technologies, Israel) is an external support device for autologous arteriovenous fistula (AVF) designed to improve anastomotic blood flow and reduce neointimal hyperplasia. However, different studies have shown that the efficacy of the VasQ device in improving AVF is inconsistent. The purpose of this study was to conduct a meta-analysis to further evaluate the efficacy and safety of the VasQ device.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Two reviewers independently searched studies published in PubMed, EMBASE, Cochrane, Web of Science, CNKI, and Wan Fang databases from inception to 2023. The Cochrane Systematic Evaluation Bias Risk Tool Version 1 was used to assess the risk of RCTS bias. The ROBINS-I tool was used to assess the risk of bias in non-randomized studies. A Single-arm meta-analysis was performed, and a random effects model was used for all analyses.

RESULTS

We identified six trials involving 146 patients and conducted a meta-analysis. The results showed that after 6 months of VasQ device treatment, the primary patency rate of AVF was [76.4% (95%CI: 0.608-0.920), p < 0.01] while the secondary patency rate was [76.5% (95%CI: 0.572-0.958), p < 0.01]. The maturity rate of AVF 1 month after surgery was [88.5% (95%CI: 0.818-0.952), p = 0.46]. The incidence of anastomotic stenosis was [8.9% (95%CI: 0.015-0.163), p = 0.23], and the incidence of anastomotic venous thrombosis was [10% (95%CI: 0.035-0.179), p = 0.38].

CONCLUSIONS

Meta-analysis data of this study show that the VasQ device has a good effect in improving the patency rate of AVF and does not increase the occurrence of adverse events. However, due to the limitation of the number and quality of included studies, more high-quality studies are needed to confirm this in the future.

Screening and surveillance of venous stenosis in AVG: Is it time to rethink our assumptions?

Guidelines make no firm recommendations about surveillance of arteriovenous grafts as several randomised trials (RCT) have not shown a clear benefit in patency. However a more thorough review of these RCT based on epidemiological principles reveals significant limitations. In particular a key weakness of these older studies is the interventions performed for venous stenosis detected that was largely angioplasty. However, the observational data of modern stent-grafts shows a clear benefit over angioplasty, and thus seems to suggest that a modern well considered RCT is now mandated.

Navigating Complex Anatomy During Leadless Pacemaker Implantation

Transvenous pacemakers may lead to wound site complications, such as hematomas and infections. Leadless pacemakers have eliminated these risks. However, when the central venous and/or cardiac anatomy are challenging, their implantation technique may require modification(s). Here, we discuss 3 cases of successful leadless pacemaker implantation in patients with a challenging anatomy. (Level of Difficulty: Advanced.).

Totally Endoscopic Surgery for Repairing Sinus Venosus Atrial Septal Defect Using Double-Patch Technique on Beating Heart

OBJECTIVE

Minimally invasive cardiac surgery has not been widely applied in repairing sinus venosus atrial septal defect (SV-ASD). Most were minithoracotomy using the single-patch technique for patients with anomalous pulmonary veins (APVs) connecting to the superior vena cava-right atrium (SVC-RA) junction. It is unclear whether patients with APVs draining high to the SVC can be repaired safely and effectively through port access.

METHODS

From May 2019 to October 2022, 11 consecutive SV-ASD patients with APVs connecting high to the SVC were enrolled in this prospective study. One 12 mm port and 2 trocars (5.5 mm and 10 mm) were established. The pleural and pericardial spaces were filled with CO₂. The SVC was snared just below the azygos vein. The RA incision was longitudinally extended along the SVC-RA junction to the SVC. The bovine pericardial patches were used to redirect the APV flow to the left atrium through the ASD and to enlarge the SVC and the SVC-RA junction.

RESULTS

There were no early or late deaths and no reoperations. The concomitant procedures included 5 patients (45.5%) with patent foramen ovale closure, 2 with ASD extension, and 3 with tricuspid valve repair. No endoscopic failure was recorded. The average cardiopulmonary bypass and operative times were 96 (23) min and 190 (30) min, respectively. No cases of venous stenosis or sinus node dysfunction were noted during follow-up of 16.4 ± 12.2 months.

CONCLUSIONS

SV-ASD with the APVs draining high to the SVC could be repaired safely and effectively through port access with a double-patch technique.

A critical review of surgical strategies to minimise venous stenosis in arteriovenous grafts

It is inevitable that complications arising from surgical procedures are ascribed to surgical technique, and this applies to venous stenosis (VS) in arteriovenous grafts. However, despite a wide range of cellular studies, computer modelling, observational series and clinical trials, there remains uncertainty on whether surgical technique contributes to VS. This article reviews evidence from basic science, fluid dynamics and clinical data to try and rationalise the main surgical options to modify the occurrence of venous stenosis. There is sufficient data from diverse sources to make recommendations on clinical practice (size of target vein, shape of anastomosis, angle of approach, distance from venous needling, trauma to the target vein) whilst at the same time this emphasises the need to carefully report the practical aspects of surgical technique in future clinical trials.

A Comparison Between Pressure Wire and Microcatheter Measurements for Evaluating the Cerebral Venous Pressure Gradient

Introduction: A pressure gradient of over 8 mm Hg across the stenosis (usually located in the transverse-sigmoid junction) is one of the criteria for cerebral venous stenting in idiopathic intracranial hypertension (IIH) patients. The possible inaccuracy of the traditional microcatheter-based pressure measurements has been discussed in previous studies. In the cardiology field, a dual-sensor pressure wire is routinely used for the evaluation of stenotic lesions. Using a pressure wire for cerebral vasculature was previously discussed in a small case series and case reports. In this study, we compared venous pressure measurements obtained using both a microcatheter and a pressure wire in patients who were candidates for stenting. Methods: A retrospective study was conducted, comparing the two methods of pressure measurements in 26 patients with venous stenosis. Altogether, 120 measurements were performed using both methods. Demographic characteristics, medical history, procedural details, medications, indications for the procedure, and complications were collected from the patient charts. Results: Based on an 8-mm Hg pressure gradient cutoff indication, 19 patients were found eligible to go through unilateral venous stenting based on catheter measurements alone. The wire results corroborated the catheter results in detecting all cases indicated for a stent. This finding implies a sensitivity equal to 100% for the wire measurements. There were no wire-related complications, demonstrating its safety. Conclusions: We conclude that the pressure wire is as safe as the microcatheter and can identify cases requiring intervention. A larger-scale study is needed to assess the measurement accuracy of the pressure wire in brain vasculature.

Angioarchitectural features amongst patients with unruptured brain arteriovenous malformations presenting with headache: findings from a single center retrospective review of 76 patients

Background

Brain arteriovenous malformations (AVMs) consist of abnormal connections between arteries and veins via an interposing nidus. While hemorrhage is the most common presentation, unruptured AVMs can present with headaches, seizures, neurological deficits, or be found incidentally. It remains unclear as to what AVM characteristics contribute to pain generation amongst unruptured AVM patients with headaches.

Methods

To assess this relationship, the current study evaluates angiographic and clinical features amongst patients with unruptured brain AVMs presenting with headache. Loyola University Medical Center medical records were queried for diagnostic codes corresponding to AVMs. In patients with unruptured AVMs, we analyzed the correlation between the presenting symptom of headache and various demographic and angiographic features.

Results

Of the 144 AVMs treated at our institution between 1980 and 2017, 76 were unruptured and had sufficient clinical data available. Twenty-three presented with headaches, while 53 patients had other presenting symptoms. Patients presenting with headache were less likely to have venous stenosis compared to those with a non-headache presentation (13 % vs. 36 %, p = 0.044).

Conclusions

Our study suggests that the absence of venous stenosis may contribute to headache symptomatology. This serves as a basis for further study of correlations between AVM angioarchitecture and symptomatology to direct headache management in AVM patients.

Long term clinical outcomes of portal vein stenting for symptomatic portal vein stenosis after pancreaticoduodenectomy

Gastrointestinal bleeding caused by portal vein (PV) stenosis is serious complication after pancreaticoduodenectomy (PD) The purpose of this study is to reveal the long-term clinical outcomes of PV stenting for symptomatic PV stenosis and risk factors of stent related complication.Fifteen patients who underwent portal vein stenting for symptomatic PV stenosis after PD between 2000 and 2018 were retrospectively reviewed. The whole cohort was divided into 9 patients with benign stenosis group (Group-B) and 6 patients with recurrence group (Group-R).The median follow up period was 17.0 (interquartile range 12.0-38.0) months. The technical success rate and clinical success rate was revealed at 93.3% and 86.7%. The primary patency rate of stents was 79.4% and mean patency period was 14.0 (4.0-28.0) months. There was significant difference in time to stenosis and proportion of anticoagulation treatment between 2 groups [2.0 (1.0-4.0) months vs 18.5 (2.5-50.3) months, P  = .035 and 100% vs 50%, P  = .044. In univariable analysis, stent diameter was found to have a significant correlation with stent occlusion (P  = .036).PV stenting was found to be feasible and safe in the treatment of symptomatic PV stenosis from a long term point of view.

Proctalgia secondary to rectal arteriovenous malformation and inferior mesenteric vein stenosis in a patient post liver transplant

Background

Chronic proctalgia can have a major impact upon quality of life. There are many potential aetiologies however, in some patients no cause can be identified.

Case presentation

We present a patient post liver transplant with intractable proctalgia, despite multidisciplinary management including opioids, nerve blocks and surgical intervention. An underlying rectal arteriovenous malformation (AVM) was subsequently identified and successfully treated with embolotherapy. The onset of symptoms coincided with the development of inferior mesenteric vein stenosis, likely leading to engorgement of the malformation due to impaired venous outflow. Neovascularisation secondary to the liver transplant procedure may also have contributed to growth of the lesion.

Conclusion

This is a rare presentation of rectal AVM. These lesions can be treated with minimally invasive embolisation/sclerotherapy and should be considered in cases of unexplained proctalgia.

Mega Fistulae! A case series

A mega fistula can be defined as generalized aneurysmal dilatation of arteriovenous fistula. Mega fistulae can lead to complications like high output cardiac failure, steal syndrome, skin ulceration and rupture. We describe a series of ten patients who were referred to our interventional nephrology practice for evaluation of mega fistula which had not been in use for a long time. Nine out of ten patients were post-transplant while one was pre dialysis. Five patients had Radiocephalic while four had Brachiocephalic and one had Brachial artery to Median Cubital vein fistula. All except one patient had severe outflow stenosis. The most common site of stenosis in Radiocepahlic and Brachiocepahlic fistula was cephalic vein at the elbow and cephalic arch respectively. Half of the patients had chronic total occlusion of the outflow vein. Successful angioplasty was done in only two patients. Seven patients underwent ligation while one had spontaneous thrombosis of the fistula. None of the patients had regular surveillance of their access for a long time as they were not on dialysis. Unrecognized and uncorrected outflow stenosis over a long time period can lead to creation of mega fistula. Once a mega fistula develops there are not many treatment options other than ligation. This leads to loss of the access which might be needed in future. Continuous access surveillance in patients who are not on dialysis is important to prevent complications like mega fistula.

Extract-stent-replace for treatment of upper baffle stenosis with pacing leads after atrial switch procedures for transposition of the great arteries: An approach to avoid "jailing" the lead

INTRODUCTION

Venous stenosis is a late complication of the atrial switch (Mustard/Senning) procedure seen in patients with transposition of the great arteries ( d-TGA). Many atrial switch patients require cardiac implantable electronic devices (CIEDs) which further increases the incidence of venous stenosis. Stenosis of the superior limb of the systemic venous pathway (SLSVP) in the presence of CIED leads presents a management challenge. We propose a method for navigating SLSVP stenosis in atrial switch patients with CIEDs.

METHODS

The pulse generator and leads were removed using standard extraction techniques. Axillary access was retained via existing leads or new access was obtained. The interventional cardiology team, via groin access, performed stent-angioplasty of the stenotic SLSVP. After stent deployment, the axillary access wire was snared from below, guided through the stent, and pulled into a long groin sheath. A sheath was then advanced over the axillary wire and into the groin sheath creating a path for passage of leads through the stent. New leads were advanced through the axillary sheath into the heart. Leads were secured using standard techniques.

RESULTS

All patients had a history of d-TGA and prior atrial switch procedures. In each case, there was stenosis of the SLSVP in the setting of a CIED lead. There were no immediate complications and there was no restenosis on follow-up.

CONCLUSION

Post-atrial switch patients with CIEDs can develop stenosis of the SLSVP. A collaboration between electrophysiology and interventional cardiology can allow for device extraction, stent-angioplasty, and lead reimplantation to avoid "jailing" the leads.

Safety and Clinical Outcomes after Transverse Venous Sinus Stenting for Treatment of Refractory Idiopathic Intracranial Hypertension: Single Center Experience

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a syndrome of elevated intracranial pressure of unknown etiology. Unilateral or bilateral transverse sinus (TS) or transverse-sigmoid junction stenosis is present in about 30%-93% of these patients. There is an ongoing debate on whether venous sinus stenosis is the cause of IIH or a result of it. The subset of IIH patients who continue to have clinical deterioration despite maximum medical therapy is termed as "refractory IIH." Traditionally, cerebrospinal fluid diversion surgeries (ventriculoperitoneal shunt and lumboperitoneal shunt) and optic nerve sheath fenestration (ONSF) were the mainstays of treatment for refractory IIH. In the last decade, venous sinus stenting (VSS) has emerged as a safe and effective option for treating refractory IIH patients with venous sinus stenosis. Through this study, we want to share our experience with venous stenting in refractory IIH patients with venous sinus stenosis associated with a significant pressure gradient (≥10 mm Hg).

METHODS

Retrospective chart review of all the patients diagnosed with refractory IIH who underwent VSS or angioplasty at our comprehensive stroke center from November 2016 to March 2019.

RESULTS

A total of seven refractory IIH patients underwent VSS or angioplasty within the specified period. The mean age was 39 years. Eighty-five percent of the patients were women (n = 6). The mean body mass index (BMI) was 37 kg/m². Headache was the most common symptom (85%, n = 6) followed by transient visual obscurations (71%, n = 5) and pulsatile tinnitus (57%; n = 4). All patients had papilledema. Fifty-seven percent of patients (n = 4) had impaired visual field. Mean lumbar opening pressure was 40.6 cm H₂O (SD = 9.66; 95% CI = 33.5-47.7). All patients were on maximum doses of acetazolamide ± furosemide. Six patients (85%) had dominant right transverse-sigmoid sinus. Fifty-seven percent of the patients had severe right transverse ± sigmoid sinus stenosis (n = 4) and the rest (43%) had bilateral TS stenosis (n = 3). Prestenting mean trans-stenosis pressure gradient was 18 mm Hg (SD = 6.16; 95% CI = 13.43-22.57). Six patients (85%) were treated with TS stenting and one (15%) with only angioplasty. Poststenting mean trans-stenosis pressure gradient was 4.8 mm Hg (SD = 6.6; 95% CI = -0.1-9.7). All patients were able to come off their medications with significant improvement in neurological and ophthalmological signs and symptoms. No procedure-related complications occurred.

CONCLUSION

TS stenting ± angioplasty is a safe and effective means of treating refractory IIH with venous sinus stenosis associated with a significant pressure gradient (≥10 mm Hg).

Venous Sinus Stenting using Transcranial Access for the Treatment of Idiopathic Intracranial Hypertension in a Pediatric Patient

A 4-year-old male with headaches, papilledema, intracranial hypertension, and bilateral transverse sinus (TS) stenosis underwent attempted percutaneous placement of a right TS stent. Stent deployment was not technically feasible due to the stiffness of the stent and tortuosity of the patient's jugular bulb. Therefore, the patient underwent hybrid endovascular stenting of the right TS using neuronavigation and direct access of the TS following a single burr hole craniectomy. Two Express 8 mm × 17 mm balloon-mounted stents were deployed into the right TS, which resulted in obliteration of the preexisting trans-stenosis pressure gradient and decreased intracranial parenchymal pressure as monitored through an intracranial pressure bolt. The patient's headaches and papilledema resolved, and follow-up imaging demonstrated no in-stent or stent-adjacent stenosis. This case demonstrates the feasibility of combining minimally invasive open surgical access to allow direct cannulation for venous sinus stenting.

Percutaneous mechanical thrombectomy combined with catheter-directed thrombolysis in the treatment of acute pulmonary embolism and lower extremity deep venous thrombosis: A novel one-stop endovascular strategy

Objective This study was performed to evaluate the efficacy and feasibility of percutaneous mechanical thrombectomy (PMT) combined with catheter-directed thrombolysis (CDT) in patients with acute pulmonary embolism (APE) and lower extremity deep venous thrombosis (LEDVT). Methods In total, 20 consecutive patients with APE and LEDVT were prospectively selected for PMT combined with CDT. Mechanical thrombus fragmentation and aspiration using a pigtail rotation catheter followed by CDT was performed in each patient. Details regarding the patients' clinical presentation and outcome, pulmonary status parameters (pulmonary arterial pressure, partial pressure of oxygen in arterial blood, Miller score, thigh and calf circumference, and shock index), and lower extremity parameters (thrombus-lysis grade and Villalta scale score) were recorded. Results All 20 patients' clinical manifestations significantly improved. Both the clinical success rate and technical success rate were 100%. No major adverse events occurred during hospitalization. Four patients developed iliac vein compression syndrome and underwent stent implantation in the iliac vein. No pulmonary embolism recurred within 16.5±6.8 months of follow-up. Conclusions The combination of PMT and CDT is a safe and effective treatment for APE and LEDVT with good short- and intermediate-term clinical outcomes.

Balloon venoplasty opens the road for an implantable defibrillator patient with complex stenosis

There is an increasing need for physicians to handle venous obstructions in pacemaker/implantable cardioverter-defibrillator implants. Venoplasty performed by an experienced operator is a simple, safe, and fast way to manage this situation and proceed to implant. Compared to other approaches, this strategy may offer particular advantages.

Sex differences in venous stenosis and occlusion in patients with endocardial leads

Venous stenosis and occlusion (VSO) in the presence of endocardial leads constitute one of the complications of permanent cardiac pacing. At present there are no scientific reports on the influence of sex on the incidence of VSO.

AIM

The aim of the study was to examine the influence of sex on the incidence of VSO in patients with earlier implanted endocardial leads in a single-center retrospective analysis.

MATERIALS AND METHODS

The material consists of 284 records of consecutive patients admitted to hospital to undergo electrotherapy procedures. In all patients a contrast venography for ipsilateral venous confluence was performed before the procedure. Patients were divided into two groups according to sex criterion. Groups were compared concerning following parameters: demographic characteristics, cardiac implantable electronic device (CIED) characteristics, comorbidities, CHA2DS2-VASc score, selected risk factors for VSO.

RESULTS

Group I consist of 101 females, whereas group II consist of 183 males. Both groups did not differ significantly for age, number of implanted endocardial leads and lead dwell time. In the cohort males were with significantly greater burden of morbidity, reflected by the mean result of CHA2DS2-VASc (P=0.0098). In males there was significantly more often chronic heart failure (P<0.0001), chronic obstructive pulmonary disease (P=0.0450) and tobacco use (P=0.0159). Males had more ICD implanted than females (P=0.0270). In the examine cohort 88 patients (31%) had VSO. There was no statistically significant difference in terms of presence of VSO between females and males (P=0.4685). The detailed analysis of the patients with VSO divided according to sex revealed higher morbidity in males.

CONCLUSIONS

The equality of VSO incidence in groups of males and females along with the predominance of factors protecting against VSO in group of males support the assumption that female gender is a protective factor against the development of VSO, equally as known protective factors in males.

Venous stenosis and occlusion in the presence of endocardial leads in patients referred for transvenous lead extraction

Objective The aim of this study was to evaluate the incidence of venous stenosis and occlusion (VSO) in patients referred for transvenous lead extraction (TLE) with regard to the indications for this treatment and to analyse the influence of VSO on efficacy, complications and technical challenges of TLE procedures. Methods The material consists of 133 consecutive TLE procedure records. The contrast venography examination of the ipsilateral access vein was performed prior to the operation. The whole study population was divided into two subgroups, based on the presence (subgroup I) or absence (subgroup II) of VSO. Results Phlebography was performed in 133 patients with age ranging from 25.7 to 86.1 years, 44 female (33.1%). The VSO was confirmed in 48 (36.1%) patients - subgroup I. Most of the patients were referred to TLE due to non-infectious reasons (100 pts-75.2%). The absence of VSO was observed substantially more frequently in patients with diabetes (P = 0.02). Procedural success rate reached 93.3% in subgroup I and 98.8% in subgroup II (P = 0.1). There was no significant difference in the use of advanced tools and alternative access sites. Conclusion The presence of VSO can be expected in one third of patients referred for lead extraction. There is no association between indication for TLE (infected or noninfected lead extraction) and the incidence of VSO. Diabetes proved to have a protective effect on venous patency in the previously mentioned group. VSO does not influence the effectiveness, safety, and the use of additional tools during TLE procedures.

Concurrent Angioplasty Balloon Placement for Stent Delivery through Jugular Venous Bulb for Treating Cerebral Venous Sinus Stenosis. Technical Report

OBJECTIVE

To report upon technique of concurrent placement of angioplasty balloon at the internal jugular vein and sigmoid venous sinus junction to facilitate stent delivery in two patients in whom stent delivery past the jugular bulb was not possible.

CLINICAL PRESENTATION

A 21-year-old woman and a 41-year-old woman with worsening headaches, visual obscuration or diplopia were treated for pseudotumor cerebri associated with transverse venous stenosis. Both patients had undergone primary angioplasty, which resulted in improvement in clinical symptoms followed by the recurrence of symptoms with restenosis at the site of angioplasty.

INTERVENTION

After multiple attempts at stent delivery through jugular venous bulb were unsuccessful, a second guide catheter was placed in the ipsilateral internal jugular vein through contralateral femoral venous approach. A 6 mm × 20 mm (left) or 5 × 15 mm (right) angioplasty balloon was placed across the internal jugular vein and sigmoid sinus junction and partially inflated until the inflation and relative straightening of the junction was observed. In both patients, the internal jugular vein and sigmoid sinus junction was successfully traversed by the stent delivery system in a parallel alignment to inflated balloon. Balloon mounted stent was deployed at the site of restenosis with near complete resolution of lumen narrowing delivery and improvement in clinical symptoms.

CONCLUSION

We report a technique for realignment and diameter change with concurrent placement and partial inflation of angioplasty balloon at the jugular venous bulb to facilitate stent delivery into the sigmoid and transverse venous sinuses in circumstances where multiple attempts at stent delivery are unsuccessful.

Resolution of inferior venous baffle leak and total venous occlusion using a bare stent and the gore(®) excluder( ®) aortic extension in transposition of the great arteries after mustard procedure

We present a patient with a history of Mustard repair for transposition of the great arteries. The patient presented with complete inferior venous baffle obstruction and a large baffle leak after several years of cyanosis. Complete relief of the obstruction and exclusion of the baffle leak were accomplished with the use of a combination of bare metal stenting and the Gore(®) Excluder(®) aortic extender. To our knowledge, this represents the first reported use of the Gore(®) Excluder(®) aortic extender in the setting of inferior venous baffle leak and associated total inferior vena cava obstruction. © 2015 Wiley Periodicals, Inc.

Venous Stenosis After Transvenous Lead Placement: A Study of Outcomes and Risk Factors in 212 Consecutive Patients

BACKGROUND

Venous stenosis is a common complication of transvenous lead implantation, but the risk factors for venous stenosis have not been well defined to date. This study was designed to evaluate the incidence of and risk factors for venous stenosis in a large consecutive cohort.

METHODS AND RESULTS

A total of 212 consecutive patients (136 male, 76 female; mean age 69 years) with existing pacing or implantable cardioverter-defibrillator systems presented for generator replacement, lead revision, or device upgrade with a mean time since implantation of 6.2 years. Venograms were performed and percentage of stenosis was determined. Variables studied included age, sex, number of leads, lead diameter, implant duration, insulation material, side of implant, and anticoagulant use. Overall, 56 of 212 patients had total occlusion of the subclavian or innominate vein (26%). There was a significant association between the number of leads implanted and percentage of venous stenosis (P=0.012). Lead diameter, as an independent variable, was not a risk factor; however, greater sum of the lead diameters implanted was a predictor of subsequent venous stenosis (P=0.009). Multiple lead implant procedures may be associated with venous stenosis (P=0.057). No other variables approached statistical significance.

CONCLUSIONS

A significant association exists between venous stenosis and the number of implanted leads and also the sum of the lead diameters. When combined with multiple implant procedures, the incidence of venous stenosis is increased.

Changes in cerebral venous sinuses diameter after lumbar puncture in idiopathic intracranial hypertension: a prospective MRI study

BACKGROUND

Idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure (ICP) without a clear cause. Recently it was shown that in more than 90% of the IIH patients there is stenosis of the transverse dural sinuses. In this study we assessed the changes in diameter of cerebral veins after lumbar puncture, in order to have some more insight regarding the volume and pressure influence on cerebral veins.

METHODS

We prospectively included 13 patients suspected with IIH, admitted for investigation in the Soroka medical center. All the patients had a lumbar puncture (LP) with opening pressure measurement and CSF analysis, and two MRI-MRV studies: one before the LP and one after it. Measurements of the cerebral venous sinuses diameter were performed.

RESULTS

Significant stenosis of both transverse sinuses was found before LP in IIH patients with an average diameter of 1.77 mm of the right TS, and 1.57 mm of the left TS. After the LP, there was a significant increase in all venous sinuses diameters (P < .05). There was no correlation between the changes in diameter of the venous sinuses after LP and opening pressure measured or BMI.

CONCLUSIONS

Our results support other studies and demonstrated narrowing of the transverse sinuses in IIH patients. The main finding of this study is the increase in cerebral sinuses diameter after LP. This observation should be considered when evaluating cerebral venous sinuses after LP. A larger scale study is warranted to validate our findings.

Endovascular management of chronic upper extremity deep vein thrombosis and superior vena cava syndrome

Chronic upper extremity deep vein thrombosis (UEDVT) and superior vena cava syndrome (SVCS) are important and underdiagnosed entities that are associated with significant morbidity, and both are becoming increasingly common due to the use of indwelling catheters and implantable central venous access devices. Currently, as many as 25% of patients with an indwelling catheter are diagnosed with chronic UEDVT or venous stenosis. SVCS is most commonly seen in the setting of malignancy, especially lung cancer and lymphoma. Endovascular management of chronic UEDVT and SVCS is accepted as an important first-line treatment given its high overall success rate and low morbidity as compared with medical and surgical treatments. In this article, the indications for treatment, complications, and success rates of the endovascular management of UEDVT and SVCS are reviewed. Relevant findings on presentation and physical exam as well as various imaging modalities and imaging findings are evaluated. Details of preprocedure evaluation, relevant anatomy, and avoidance of potential complications are discussed.

The perfect crime? CCSVI not leaving a trace in MS

BACKGROUND

Multiple sclerosis (MS) is a chronic, inflammatory demyelinating disease of the central nervous system, believed to be triggered by an autoimmune reaction to myelin. Recently, a fundamentally different pathomechanism termed 'chronic cerebrospinal venous insufficiency' (CCSVI) was proposed, provoking significant attention in the media and scientific community.

METHODS

Twenty MS patients (mean age 42.2 ± 13.3 years; median Extended Disability Status Scale 3.0, range 0-6.5) were compared with 20 healthy controls. Extra- and intracranial venous flow direction was assessed by colour-coded duplex sonography, and extracranial venous cross-sectional area (VCSA) of the internal jugular and vertebral veins (IJV/VV) was measured in B-mode to assess the five previously proposed CCSVI criteria. IJV-VCSA ≤ 0.3 cm(2) indicated 'stenosis,' and IJV-VCSA decrease from supine to upright position 'reverted postural control.' The sonographer, data analyser and statistician were blinded to the patient/control status of the participants.

RESULTS

No participant showed retrograde flow of cervical or intracranial veins. IJV-VCSA ≤ 0.3 cm(2) was found in 13 MS patients versus 16 controls (p=0.48). A decrease in IJV-VCSA from supine to upright position was observed in all participants, but this denotes a physiological finding. No MS patient and one control had undetectable IJV flow despite deep inspiration (p=0.49). Only one healthy control and no MS patients fulfilled at least two criteria for CCSVI.

CONCLUSIONS

This triple-blinded extra- and transcranial duplex sonographic assessment of cervical and cerebral veins does not provide supportive evidence for the presence of CCSVI in MS patients. The findings cast serious doubt on the concept of CCSVI in MS.

Neoangiogenesis and the presence of progenitor cells in the venous limb of an arteriovenous fistula in the rat

Venous injury and attendant venous stenosis are major contributors to the failure of hemodialysis vascular accesses. This report describes the presence of neoangiogenesis in the intima and adventitia of the venous limb of an arteriovenous (AV) fistula in the rat, the latter induced by creating an aortocaval fistula. Immunohistochemistry of the venous limb demonstrated the presence of c-Kit-positive cells lining new microvessels with lumen formation and that these c-Kit-positive cells exhibited either a smooth muscle phenotype as reflected by concomitant expression of calponin, or an endothelial phenotype as reflected by expression of endothelial nitric oxide synthase (eNOS). Western analysis confirmed upregulation of eNOS in the venous limb of the AV fistula. Measurement of systemic concentrations of angiogenic cytokines, namely, monocyte chemotactic protein-1, stromal cell-derived factor-1 (SDF-1), cytokine-induced neutrophil chemoattractant, and VEGF, failed to reveal an increase in these cytokines either at 3 or 10 wk after creation of the AV fistula. The angiogenic cytokines VEGF and SDF-1 were not upregulated in the venous limb of the AV fistula either at 2 or 16 wk. We conclude that in this model of an AV fistula in the rat, neoangiogenesis occurs and is constituted, at least in part, by bone marrow-derived cells, the latter differentiating to exhibit either an endothelial or smooth muscle phenotype. In view of these findings, we suggest that this model may offer an experimental approach by which to explore the evolution and significance of neoangiogenesis in the formation and pathobiology of vascular plaques, and the mechanisms that promote dysfunction of hemodialysis AV fistulas.