Clinical impact of assessing thrombus age using magnetic resonance venography prior to catheter-directed thrombolysis.

OBJECTIVES: Magnetic resonance venography (MRV) is underutilized in the evaluation of thrombus properties prior to endovascular treatment but may improve procedural outcomes. We therefore investigated the clinical impact of using a dedicated MRV scoring system to assess thrombus characteristics prior to endovascular intervention for iliofemoral deep vein thrombosis (DVT). METHODS: This is a post hoc analysis of data from the CAVA trial ( Clinicaltrials.gov :NCT00970619). MRV studies of patients receiving ultrasound-accelerated catheter-directed thrombolysis (CDT) for iliofemoral DVT were reviewed. Thrombus age-related imaging characteristics were scored and translated into an overall score (acute, subacute, or old). MRV scores were compared to patient-reported complaints. MRV-scored groups were compared for CDT duration and success rate. RESULTS: Fifty-six patients (29 men; age 50.8 ± 16.4 years) were included. Using MRV, 27 thrombi were classified acute, 17 subacute, and 12 old. Based on patient-reported complaints, 11 (91.7%) of these old thrombi would have been categorized acute or subacute, and one (3.7%) of the acute thrombi as old. Average duration of CDT to > 90% restored patency differed significantly between groups (p < 0.0001): average duration was 23 h for acute thromboses (range: 19-25), 43 h for subacute (range: 41-62), and 85 h for old thromboses (range: 74-96). CDT was almost eleven times more successful in thromboses characterized as acute and subacute compared to old thromboses (OR: 10.7; 95% CI 2.1-55.5). CONCLUSION: A dedicated MRV scoring system can safely discriminate between acute, subacute, and old thromboses. MRV-based selection is predictive of procedural duration and success rate and can help avoid unnecessary complications. KEY POINTS: • Thrombus age, characterized by MRV as acute, subacute, and old, can predict CDT duration and probability of success. • Accurate pre-interventional MRV-based thrombus aging has the potential to facilitate identification of eligible patients and may thus prevent CDT-related complications.

Outcome of stenting in central venous obstruction of benign etiology.

Background: The aim of this study is to evaluate long term outcome in patients treated for benign superior vena cava (SVC) syndrome by endovascular techniques. Patients and methods: Between 2015 and 2018, 62 patients suffering from central venous obstruction of benign etiology underwent balloon angioplasty with stent placement for venous obstruction in our department. Patency was assessed clinically, using duplex ultrasound in all patients or with CT-phlebography in selected cases. Results: Median age was 60 years (23-83), forty-one patients (66%) had central venous devices. Swelling of the arm and face were the main symptoms (71%). During the median follow up of 22 months (9-38), cumulative primary patency was 71% after venous stenting. The cumulative assisted primary and the secondary patency were 85% and 92%, respectively. Conclusions: Recanalization and stenting of central vein obstruction has turned out to be the technique of reference and provides satisfactory mid-term patency rates. After adjusting for the risk factors, presence of AV-fistula remained a significant risk factor for recurrent stenosis or loss of patency after intervention.

The Role of May-Thurner Syndrome in Recurrent Thrombosis after Catheter-Directed Thrombolysis of Deep Vein Thrombosis.

BACKGROUND: May-Thurner syndrome (MTS) leads to an increased incidence of deep vein thrombosis (DVT). Early thrombus removal decreases the post-thrombotic morbidities. Our aim was to better elucidate the relationship between MTS and venous patency after catheter-directed thrombolysis (CDT). METHODS: The medical records of all patients who underwent CDT from January 2005 to December 2011 due to acute DVT were reviewed retrospectively. Patient characteristics and clinical variables were evaluated to determine association with vein patency. RESULTS: A total of 51 male and 31 female with a mean age of 34.9 years were treated with CDT. During a median follow-up of 91.7 months, primary patency and secondary patency of all patients were 79.3% and 87.3%, respectively. The presence of MTS was the only significant predictor factor of patency. CONCLUSIONS: The residual stenosis caused by MTS is a risk for recurrent DVT and should be treated with stenting to improve the outcome.

Illusory Angiographic Signs of Significant Iliac Vein Compression in Healthy Volunteers.

OBJECTIVE: Iliac vein compression syndrome can cause severe leg symptoms. In clinical practice, it remains a challenge to differentiate which compression is clinically relevant. The aim of the current study was to assess the general treatment indications and the prevalence of angiographic signs of iliac vein compression in a group of healthy participants. METHODS: This was a prospective cohort study. A total of 20 healthy volunteers (median age 21, range 20-22 years) were recruited through advertisement and underwent angiography of the iliac veins. When no compression signs were present, a balloon occlusion was performed. Additionally, a 10 item survey regarding indications for venous stenting was developed and sent to 30 vascular specialists treating patients with deep venous obstruction. RESULTS: In 16 (80%) participants, at least two signs indicative of May-Thurner compression were seen. In three (15%) subjects, narrowing of the common iliac vein without collaterals was shown and one (5%) did not show any signs of obstruction. In 23 (70%) of the survey responders, collaterals were found to be the most typical sign indicative of significant venous obstruction. An angiographic sign of >50% compression was found to be an indication to stent in 55% of responders. CONCLUSION: This study demonstrates a remarkably high percentage of generally accepted signs of significant iliac vein obstruction (May-Thurner compression) on venography in healthy young subjects. Diagnosis of true iliac vein obstruction remains a major challenge, which mostly leans on improvement of clinical symptoms rather than imaging findings. Treating the patient rather than the image seems to be a valid principle all the more.

The Effect of Stenting on Venous Hypertension: Results Using a Treadmill Stress Test with Invasive Pressure Measurements in Patients with Iliofemoral Venous Obstruction.

OBJECTIVES: The primary aim was to investigate whether stenting of post-thrombotic iliofemoral obstruction reduces venous hypertension. The secondary aim was to establish whether improvement in haemodynamic parameters impacts on quality of life. METHODS: In this prospective observational study, 12 participants with unilateral post-thrombotic obstruction of the iliac and/or common femoral veins (CFVs) underwent a treadmill stress test with invasive pressure measurements in the CFVs and dorsal foot veins of both affected and non-affected limbs. This was performed the day before and 3 months after stenting the obstructed tract. Paired sample t-tests were used to compare the treatment effect and univariable linear regression analysis to determine the association with improvement in quality of life. RESULTS: Before treatment, CFV pressure increased 34.8 ± 23.1 mmHg during walking in affected limbs compared with 3.9 ± 5.8 mmHg in non-affected limbs. This pressure rise decreased to 22.3 ± 24.8 mmHg after 3 months follow up compared with a 4.0 ± 6.0 mmHg increase in non-affected limbs (-26.2 mmHg difference; 95% CI -41.2 to -11.3). No such effect was found in the dorsal foot veins. The VEINES-QOL increased 25.3 ± 11.3 points after stenting and was significantly associated with a decrease in CFV pressure rise during walking (regression coefficient 0.4; 95% CI 0.1-0.6). CONCLUSION: Stenting of post-thrombotic iliofemoral obstruction significantly reduces venous hypertension in the common femoral vein and correlates with an improvement in the quality of life. Larger studies with a broader range of degree of obstruction need be performed to assess whether pre-stenting pressure measurements can predict post stenting clinical success.

The need for a timely diagnostic workup for patients with venous leg ulcers.

OBJECTIVE: To explore the need for an extended diagnostic workup in patients with venous leg ulcers (VLUs) and to establish the prevalence of the underlying causes of VLU. METHOD: This retrospective cohort study analysed data from patients with VLU. The visual analogue scale (VAS) was used for pain assessment. The ankle-brachial index (ABI) was measured to exclude patients with arterial pathology. A duplex was performed. All patients received a wound treatment plan and ambulatory compression therapy. Continuous variables were presented as mean±standard deviation (SD) or median and interquartile range (IQR). Mann-Whitney U test and Kruskal-Wallis were used. When normally distributed, an independent sample t-test was used. RESULTS: A total of 70 patients were recruited. Of these, 18 (25.7%) experienced a VLU once and 52 (74.3%) had a recurrent VLU. Treatment of the underlying lesions was performed in almost 30% of patients. Patients who were treated showed almost two times slower healing rates compared with those who were not treated for an underlying pathology. The mean time in patient referral exceeded two years, and patients who did not see their GP were treated by nurses who did not provide regular feedback the GP; as a result, compression therapy was not always adequate. CONCLUSION: Patients with a VLU showing no signs of healing after 2 months should be referred to a dedicated wound care centre to avoid delays.

Gadobutrol versus gadofosveset-trisodium in MR venography of the lower extremities.

OBJECTIVES: MR venography (MRV) protocols have used bloodpool contrast agents and long scan sequences to identify patients suitable for treatment and preoperatively. However, variable availability of bloodpool contrast agents, high costs and a need to shorten acquisition times for routine MR protocols hamper everyday practice. MATERIALS: 20 patients (11 men; mean age 54 ± 11.8 years; body mass index 23.6 ± 2.5) were enrolled in this prospective study. An intra-individual comparison of image quality, interpretation and findings for two different contrast agents (regular gadolinium contrast agent gadobutrol vs. bloodpool contrast agent gadofosveset-trisodium) and two different scan protocols (long acquisition time protocol using a high-resolution fast field echo (FFE) sequence vs. short acquisition time protocol using an ultra-fast gradient echo (GE) sequence) were performed. RESULTS: Image quality (average of 4.94 vs. 4.92 on a five-point scale), interpretation and contrast-to-noise ratio (44 vs. 45) were equal for both contrast agents. Image findings showed no statistical significant differences between the MR protocols or contrast agents (overall p = 0.328). CONCLUSIONS: For high-resolution MRV, it is possible to replace gadofosveset-trisodium with gadobutrol. Furthermore, an ultra-fast GE sequence for MRV might considerably shorten acquisition time, without loss of image quality or diagnostic yield. KEY POINTS: • High-quality MRV can be performed with a regular gadolinium-based contrast agent. • Ultra-fast GRE vs. HR-FFE MRV: equally suitable for evaluation of venous obstruction. • Regular gadolinium-based contrast agent can supersede a bloodpool contrast agent for MRV. • Equal confidence for gadobutrol vs gadofosveset-trisodium in MRV. • MRV accessible for routine daily practice.

Endovascular Treatment of a Renocaval Arteriovenous Fistula Induced Inferior Vena Cava Aneurysm.

Caval aneurysms are very rare but potentially lethal. Discussion about the need for treatment rises on individual basis. Based on the underlying etiology, a well-considered treatment plan should be made. Possible complications for invasive treatment and conservative management should be carefully weighed against each other. We present a patient with a caval aneurysm due to an arteriovenous fistula which we treated with endovascular embolization. Six months after treatment the patient is asymptomatic and the aneurysm size is decreased.

Prospective study of a single treatment strategy for local tumescent anesthesia in Muller phlebectomy.

BACKGROUND: Ambulatory Muller phlebectomy for varicose veins can be performed under local anesthesia. However, subcutaneous injection of local tumescent anesthetics may cause discomfort because of acidity of the solution. Addition of sodium bicarbonate lowers the acidity of anesthetic solutions, which might cause less pain. The objective of this study was to study whether alkalinization of the local anesthetic solution with sodium bicarbonate 1.4% decreases perioperative pain during Muller phlebectomies. METHODS: It is a double-blind single-center randomized controlled trial. In all, 101 patients scheduled for ambulatory Muller phlebectomy were randomized to receive either local anesthesia with alkalinized solution (lidocaine 1% and epinephrine in sodium bicarbonate 1.4%) or standard solution (lidocaine 1% and epinephrine in saline 0.9%). Primary outcome was pain during injection of local anesthetics with the use of the Visual Analogue Scale (VAS). Secondary outcomes were peroperative and postoperative pain, use of analgesics, patient satisfaction, return to function, and complications. RESULTS: Patients receiving subcutaneous injection of local anesthetics diluted in sodium bicarbonate 1.4% experienced significantly less pain during injection compared with patients treated with standard anesthetic solution (VAS, 1.75 ± 1.8 vs. 3.55 ± 2.2, P < 0.00). Peroperative and postoperative pain, complication rates, use of analgesics, patient satisfaction, return to function, and complications did not differ between the 2 groups (P > 0.10). CONCLUSIONS: Alkalinization of local anesthetic solution with sodium bicarbonate 1.4% significantly improves patient comfort during injection of local tumescent anesthesia.

A multicenter, randomized, dose-finding study of mechanochemical ablation using ClariVein and liquid polidocanol for great saphenous vein incompetence.

BACKGROUND: The purpose of the present study was to identify the ideal polidocanol (POL) concentration for mechanochemical ablation (MOCA) of the great saphenous vein (GSV) using the ClariVein system (Merit Medical, South Jordan, Utah). METHODS: We performed a multicenter, randomized, controlled, single-blind trial with a follow-up period of 6 months. Patients with symptomatic primary truncal GSV incompetence were randomized to MOCA + 2% POL liquid (2% group) or MOCA + 3% POL liquid (3% group). The primary outcome was technical success (TS), defined as an open part of the treated vein segment of ≤10 cm in length. The secondary outcomes were alternative TS, defined as ≥85% occlusion of the treated vein segment, postoperative pain, venous clinical severity scores, Aberdeen varicose vein questionnaire scores, and short-form 36-item health survey questionnaire scores, and complications. RESULTS: From 2012 to 2018, 364 patients (375 limbs) were included, of which, 189 limbs were randomly allocated to the 2% group and 186 to the 3% group. The TS rate at 6 months was 69.8% in the 2% group vs 78.0% in the 3% group (P = .027). A higher overall TS rate was seen in GSVs of ≤5.9 mm compared with GSVs >5.9 mm (84.3% vs 59.5%, respectively; P < .001). The alternative TS rate at 6 months was 61.4% in the 2% group and 67.7% in the 3% group (P = .028). The venous clinical severity scores, Aberdeen varicose vein questionnaire scores, and most short-form 36-item health survey questionnaire domains had improved in both groups (P < .002). Postprocedural pain was low. Two pulmonary embolisms and two deep vein thromboses were seen. Superficial venous thrombosis had occurred more often in the 3% group (18 vs 8 in the 2% group; P = .033). CONCLUSIONS: The results from the present study showed a higher success rate for MOCA with 3% POL liquid than for MOCA with 2% POL liquid at 6 months of follow-up. However, the difference in quality of life was not significant. Long-term follow-up studies are required to investigate whether these results will be sustained in the future.

CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis on Preventing Post-Thrombotic Syndrome) Trial: Long-Term Follow-Up Results.

Background The CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis Versus Anticoagulation for the Prevention of Post-Thrombotic Syndrome) trial did not show a reduction of post-thrombotic syndrome (PTS) after additional ultrasound-accelerated catheter-directed thrombolysis in patients with acute iliofemoral deep vein thrombosis at 1-year follow-up. This prespecified analysis of the CAVA trial aimed to determine the impact of additional thrombolysis on outcomes of PTS at long-term follow-up. Methods and Results Patients aged 18 to 85 years with a first-time acute iliofemoral deep vein thrombosis were included and randomly assigned (1:1) to either standard treatment plus ultrasound-accelerated catheter-directed thrombolysis or standard treatment alone. The primary outcome was the proportion of PTS (Villalta score ≥5 on 2 occasions ≥3 months apart or venous ulceration) at the final follow-up visit. Additionally, PTS according to the International Society on Thrombosis and Haemostasis (ISTH) consensus definition was assessed to allow external comparability. Major bleedings were the main safety outcome. At a median follow-up of 39.0 months (interquartile range, 23.3-63.8), 120 patients (79.8%) participated in the final follow-up visit: 62 from the intervention group and 58 from the standard treatment group. PTS developed in 19 (30.6%) versus 26 (44.8%) patients, respectively (odds ratio [OR], 0.54; 95% CI, 0.26 to 1.15 [P=0.11]), with an absolute difference between groups of -14.2% (95% CI, -32.0% to 4.8%). Using the ISTH consensus definition, a significant reduction in PTS was observed (29 [46.8%] versus 40 [69.0%]) (OR, 0.40; 95% CI, 0.19-0.84 [P=0.01]) with an absolute difference between groups of -22.2% (95% CI, -39.8% to -2.8%). No new major bleedings occurred following the 12-month follow-up. Conclusions The impact of additional ultrasound-accelerated catheter-directed thrombolysis on the prevention of PTS was found to increase with time. Although this study was limited by its sample size, the overall findings indicate a reduction of mild PTS without impact on quality of life. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00970619.

Association of Successful Ultrasound-Accelerated Catheter-Directed Thrombolysis with Postthrombotic Syndrome: A Post Hoc Analysis of the CAVA Trial.

BACKGROUND: The CAVA trial did not show the anticipated risk reduction for postthrombotic syndrome (PTS) after thrombus removal via additional ultrasound-accelerated catheter-directed thrombolysis (UACDT) in patients with acute iliofemoral deep vein thrombosis (IFDVT). Difficulties in achieving an effective degree of recanalization through thrombolysis may have influenced outcomes. We therefore assessed whether successful UACDT (restored patency ≥ 90%) did reduce the development of PTS. METHODS: This CAVA trial post hoc analysis compared the proportion of PTS at 1-year follow-up between patients with successful UACDT and patients that received standard treatment only. In addition, clinical impact as well as determinants of successful thrombolysis were explored. RESULTS: UACDT was initiated in 77 (50.7%) patients and considered successful in 41 (53.2%, interrater agreement κ = 0.7, 95% confidence interval 0.47-0.83). PTS developed in 15/41 (36.6%) patients in the successful UACDT group versus 33/75 (44.0%) controls (p = 0.44). In this comparison, successful UACDT was associated with lower Venous Clinical Severity Score (3.50 ± 2.57 vs. 4.82 ± 2.74, p = 0.02) and higher EuroQOL-5D (EQ-5D) scores (40.2 ± 36.4 vs. 23.4 ± 34.4, p = 0.01). Compared with unsuccessful UACDT, successful UACDT was associated with a shorter symptom duration at inclusion (p = 0.05), and higher rates of performed adjunctive procedures (p < 0.001) and stent placement (p < 0.001). CONCLUSION: Successful UACDT was not associated with a reduced proportion of PTS 1 year after acute IFDVT compared with patients receiving standard treatment alone. There was, however, a significant reduction in symptom severity and improvement of generic quality of life according to the EQ-5D. Better patient selection and optimization of treatment protocols are needed to assess the full potential of UACDT for the prevention of PTS. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number, NCT00970619.

Triage of patients with venous and lymphatic diseases during the COVID-19 pandemic - The Venous and Lymphatic Triage and Acuity Scale (VELTAS):: A consensus document of the International Union of Phlebology (UIP), Australasian College of Phlebology (ACP), American Vein and Lymphatic Society (AVLS), American Venous Forum (AVF), European College of Phlebology (ECoP), European Venous Forum (EVF), Interventional Radiology Society of Australasia (IRSA), Latin American Venous Forum, Pan-American Society of Phlebology and Lymphology and the Venous Association of India (VAI).

The coronavirus disease 2019 (COVID-19) global pandemic has resulted in diversion of healthcare resources to the management of patients infected with SARS-CoV-2 virus. Elective interventions and surgical procedures in most countries have been postponed and operating room resources have been diverted to manage the pandemic. The Venous and Lymphatic Triage and Acuity Scale was developed to provide an international standard to rationalise and harmonise the management of patients with venous and lymphatic disorders or vascular anomalies. Triage urgency was determined based on clinical assessment of urgency with which a patient would require medical treatment or surgical intervention. Clinical conditions were classified into six categories of: (1) venous thromboembolism (VTE), (2) chronic venous disease, (3) vascular anomalies, (4) venous trauma, (5) venous compression and (6) lymphatic disease. Triage urgency was categorised into four groups and individual conditions were allocated to each class of triage. These included (1) medical emergencies (requiring immediate attendance), example massive pulmonary embolism; (2) urgent (to be seen as soon as possible), example deep vein thrombosis; (3) semiurgent (to be attended to within 30-90 days), example highly symptomatic chronic venous disease, and (4) discretionary/nonurgent- (to be seen within 6-12 months), example chronic lymphoedema. Venous and Lymphatic Triage and Acuity Scale aims to standardise the triage of patients with venous and lymphatic disease or vascular anomalies by providing an international consensus-based classification of clinical categories and triage urgency. The scale may be used during pandemics such as the current COVID-19 crisis but may also be used as a general framework to classify urgency of the listed conditions.

Ultrasound-accelerated catheter-directed thrombolysis versus anticoagulation for the prevention of post-thrombotic syndrome (CAVA): a single-blind, multicentre, randomised trial.

BACKGROUND: Early thrombus removal might prevent post-thrombotic syndrome by preserving venous function and restoring flow. Previous trials comparing additional catheter-directed thrombolysis to standard treatment showed conflicting outcomes. We aimed to assess the benefit of additional ultrasound-accelerated catheter-directed thrombolysis for the prevention of post-thrombotic syndrome compared with standard therapy in patients with iliofemoral deep-vein thrombosis. METHODS: We did a multicentre, randomised, single-blind, allocation-concealed, parallel group, superiority trial in 15 hospitals in the Netherlands. Patients aged 18-85 years with a first-time acute iliofemoral deep-vein thrombosis and symptoms for no more than 14 days were randomly assigned (1:1) to either standard treatment with additional ultrasound-accelerated catheter-directed thrombolysis or standard treatment alone. Randomisation was done with a web-based automatic programme and a random varying block size (2-12), stratified by age and centre. Standard treatment included anticoagulant therapy, compression therapy (knee-high elastic compression stockings; 30-40 mmHg), and early ambulation. Additional ultrasound-accelerated catheter-directed thrombolysis was done with urokinase with a starting bolus of 250 000 international units (IU) in 10 mL NaCl followed by a continuous dose of 100 000 IU/h for a maximum of 96 h through the Ekos Endowave-system. Adjunctive percutaneous transluminal angioplasty, thrombosuction, or stenting was performed at the discretion of the physician who performed the intervention. The primary outcome was the proportion of patients with post-thrombotic syndrome at 12 months diagnosed according to the original Villalta criteria-a Villalta-score of at least 5 on two consecutive occasions at least 3 months apart or the occurrence of venous ulceration-and was assessed in a modified intention-to-treat population of all randomly assigned patients who passed screening and started treatment. The safety analysis was assessed in the same modified intention-to-treat population. This study is complete and is registered at ClinicalTrials.gov, NCT00970619. FINDINGS: Between May 28, 2010, and Sept 18, 2017, 184 patients were randomly assigned to either additional ultrasound-accelerated catheter-directed thrombolysis (n=91) or standard treatment alone (n=93). Exclusion because of screening failure or early withdrawal of informed consent resulted in 77 patients in the intervention group and 75 in the standard treatment group starting allocated treatment. Median follow-up was 12·0 months (IQR 6·0-12·0). 12-month post-thrombotic syndrome occurred in 22 (29%) patients allocated to additional treatment versus 26 (35%) patients receiving standard treatment alone (odds ratio 0·75 [95% CI 0·38 to 1·50]; p=0·42). Major bleeding occurred in four (5%) patients in the intervention group, with associated neuropraxia or the peroneal nerve in one patient, and no events in the standard treatment group. No serious adverse events occurred. None of the four deaths (one [1%] in the intervention group vs three [4%] in the standard treatment group) were treatment related. INTERPRETATION: This study showed that additional ultrasound-accelerated catheter-directed thrombolysis does not change the risk of post-thrombotic syndrome 1 year after acute iliofemoral deep-vein thrombosis compared with standard therapy alone. Although this trial is inconclusive, the outcome suggests the possibility of a moderate beneficial effect with additional ultrasound-accelerated catheter-directed thrombolysis. Further research is therefore warranted to better understand this outcome in the context of previous trials, preferably by combining the available evidence in an individual patient data meta-analysis. FUNDING: The Netherlands Organisation for Health Research and Development (ZonMw), Maastricht University Medical Centre, BTG-Interventional Medicine.

Access blood flow and the risk of complications in mature forearm and upper arm arteriovenous fistulas.

BACKGROUND/AIMS: Optimization of vascular access use in the 'fistula first' era requires comprehension of its clinical behavior. Little is known about mature arteriovenous fistula (AVF) performance and the role of fistula location. Widely used access flow (Qa) was used to analyze complication risks and functionality after first hemodialysis use. METHODS: 178 Mature AVFs were analyzed. Complication was defined as permanent failure or >or=1 intervention. Factors associated with complications and mean Qa were determined using Cox proportional-hazards and linear regression models. RESULTS: Baseline Qa was significantly lower in complicated versus uncomplicated forearm and upper arm AVFs. In complicated forearm AVFs, preoperative arterial diameter was smaller while the risk of complications was graded per 100 ml/min baseline Qa increase. Diabetics had an increased risk of upper arm AVF complications. In uncomplicated forearm AVFs, diabetes was related to lower mean Qa, and BMI to higher Qa. CONCLUSIONS: In mature AVFs, baseline Qa depends on fistula location and is related to the risk of complications in a graded manner.

Update on diagnosis and treatment strategies in patients with post-thrombotic syndrome due to chronic venous obstruction and role of endovenous recanalization.

OBJECTIVE: After a first episode of lower extremity deep venous thrombosis, post-thrombotic syndrome (PTS) develops in 20% to 50% of patients despite adequate anticoagulation. Symptoms of PTS can vary from leg swelling to venous ulceration with disabling venous claudication. It significantly affects the patient's quality of life and has considerable socioeconomic consequences. This review gives an update on diagnosis and current treatment strategies in patients with PTS due to chronic venous obstruction, in particular regarding the role of endovenous procedures. METHODS: This review article is based on a selective literature search in PubMed and the Cochrane Library. The terms "postthrombotic syndrome," "post-thrombotic syndrome," "chronic venous obstruction," "venous outflow obstruction," and "venous stent" were used as keywords. Selected publications addressed the diagnosis of and therapy for PTS. Acute deep venous thrombosis, thrombolysis, case reports, complications as a result of caval vein filters, animal experiments, PTS of the upper extremity, and PTS in children were excluded. RESULTS: In addition to conservative treatment of PTS, the following invasive procedures are also available: open surgical reconstructions, hybrid procedures, and endovenous recanalization of the occluded iliocaval venous tract with stent angioplasty. Since introduction of dedicated venous stents in 2012, technical success, patency rates, and improvement in quality of life have been at least as good as results of open surgical reconstruction if not better. CONCLUSIONS: First-line treatment should be conservative therapy. In case of therapy-resistant PTS with poor quality of life, the possibility of an invasive treatment should be evaluated. All invasive procedures are recommended with low levels of evidence. Therefore, deciding on an invasive treatment and type of procedure should be made individually. Because PTS is rarely a threat to life or limb, a minimally invasive treatment is preferred. Therefore, endovenous recanalization appears to be appropriate as the therapy of choice. In patients with involvement of the femoral confluence, endophlebectomy of the common femoral vein in addition to venous recanalization is inevitable to ensure an adequate inflow into the recanalized venous tract. It also secures a sufficient drainage of blood from the peripheral venous system. Because this hybrid procedure is burdened with a significantly higher risk of complications, strict criteria must be fulfilled to legitimize the indication for this procedure. For the best possible results to be achieved, the following perioperative and postoperative management must be considered: therapeutic anticoagulation, early mobilization, compression therapy, and systematic follow-up with duplex ultrasound.

Assessing radiation exposure to patients during endovascular treatment of chronic venous obstruction.

BACKGROUND: Post-thrombotic obstruction can be adequately treated by percutaneous transluminal angioplasty and stenting. This procedure is rapidly emerging as a minimally invasive alternative to traditional open surgical operations. However, the patient will be exposed to a significant amount of radiation during preoperative planning and operation. The aim of this study was to evaluate the amount of radiation exposure to patients during venous recanalization. METHODS: All patients undergoing endovenous recanalization from February 2016 to February 2018 were included in this study. The operations were performed in an operating room using a mobile C-arm angiography system. Indirect parameters of cumulative air kerma, kerma-area product, and fluoroscopy time (FT) were recorded concurrently with direct measurements of dose (effective dose [ED]) in the pelvic and neck area using two electronic personal dosimetry devices. The direct measured doses were then correlated with indirect parameters provided by the imaging equipment manufacturers. RESULTS: In total, 78 cases were included in the study. During a median operation time of 154.5 minutes (90-323 minutes), the median FT was 43.7 minutes (15.9-77.7 minutes). Body mass index did not correlate with FT or ED. ED correlated with duration of the intervention (r = 0.59) but better with FT, cumulative air kerma, and kerma-area product (r = 0.76, 0.94, and 1.00, respectively). No patients had evidence of radiation-induced skin injury. CONCLUSIONS: Radiation exposure to patients during endovenous recanalization does not reach the threshold to have a deterministic effect. Indirect parameters of radiation exposure correlated with direct measurements of the ED. Direct dosimetry is likely to be an unnecessary effort for these types of procedures when indirect dose metrics are available.

Patency rates and clinical outcomes in a cohort of 200 patients treated with a dedicated venous stent.

OBJECTIVE: Minimally invasive interventions by recanalization, percutaneous transluminal angioplasty, and stenting in post-thrombotic syndrome (PTS) obstructions and iliac vein compression syndrome (IVCS) have shown good results. Until recently, no dedicated venous stents were available, and stent-related issues accounted for a decrease in patency scores. The introduction of dedicated stents with more flexibility and higher radial forces could result in higher patency scores. This study focused on the outcomes of patients treated by a dedicated sinus-Venous stent (OptiMed GmbH, Ettlingen, Germany). Patency rates and clinical evaluation are described for both PTS and IVCS patients. METHODS: A total of 200 patients treated at a tertiary university referral center were analyzed. A percutaneous procedure was performed in 103 (51%) PTS patients and 48 (24%) IVCS patients. In 49 (25%) patients, a hybrid procedure was executed. Patency rates and complications were analyzed by duplex ultrasound. Clinical improvement was scored by Venous Clinical Severity Score, Villalta scale, and venous claudication rates. RESULTS: The mean age was 43.2 ± 14.5 (17-81) years, and 66% were female. Mean Villalta score decreased from 10.5 ± 4.2 (3-24) to 5.3 ± 3.8 (0-14) at the latest follow-up (P < .001). Venous Clinical Severity Score decreased by a total of 3 points (P < .001). At baseline, venous claudication was present in 132 patients, which subsided in 115 (87%). Overall patency scores revealed a primary patency of 68%, assisted primary patency of 83%, and secondary patency of 90% with a median follow-up of 12 (11-12) months. Of all included patients, 122 (61%) did not have a complication during follow-up; the most frequent complications were in-stent restenosis (n = 23) and occlusion (n = 25) of the stented tract. CONCLUSIONS: Short-term clinical results using the sinus-Venous stent are comparable to previous research. Loss of stent patency due to stent-related issues like kinking or tapering is hardly ever seen in this short-term follow-up.

A randomised controlled trial comparing venous stenting with conservative treatment in patients with deep venous obstruction: research protocol.

INTRODUCTION: Deep venous obstruction (DVO) has a great impact on quality of life (QoL) comparable to angina pectoris or chronic pulmonary disease. Post-thrombotic scar formation and May-Thurner syndrome (MTS) are the most common causes of DVO. Conventional treatment of DVO focuses on reducing pain or leg swelling by use of (pain) medication and therapeutic elastic stockings. In the past, a venous bypass was offered in severe post-thrombotic cases, but this procedure showed bad clinical and patency outcomes. With the introduction of percutaneous angioplasty and dedicated venous stents new opportunities were created. Deep venous stenting has been shown to be effective in retrospective case series. However, there is no prior research in which QoL after interventional treatment is compared with QoL after conventional treatment. Currently, there is a debate about the true additional value of interventional treatment. We investigate whether those patients who are treated with stenting experience a change in short form 36 (SF-36) and the Veines-QoL/Sym questionnaires compared with conventionally treated patients. METHODS AND ANALYSIS: This is a randomised trial comparing conservative deep venous management to interventional treatment. A total of 130 patients with post-thrombotic syndrome (PTS) or MTS, eligible for interventional percutaneous treatment, who did not have previous deep venous intervention will be included. Patients will be randomised to conservative treatment or venous stenting and stratified for the PTS or MTS subgroup. Conservative treatment consists of either one or a combination of pain medications, manual lymphatic drainage, compression stockings and regular post-thrombotic anticoagulant therapy.The primary outcome is the QoL change after 12 months compared with baseline QoL. Secondary outcomes are QoL changes at 6 weeks, clinical assessment of DVO, recurrence rate of deep venous thrombosis at 6 weeks and 12 months, and the total amount of working days lost. Intervention-specific outcomes include complications and patency. ETHICS AND DISSEMINATION: The protocol is approved by the Medical Ethics Committee of Academisch ziekenhuis Maastricht/Universiteit Maastricht, The Netherlands (protocol number NLNL55641.068.15 / METC 161008).We aim to publish the results of this study in a peer reviewed journal and present our findings at national or international conferences. TRIAL REGISTRATION NUMBER: The study protocol was registered at www.clinicaltrials.gov (registration number: NCT03026049) on 17 January 2017.