Venous Segments Research Articles

Two Year Outcome After Chronic Iliac Vein Occlusion Recanalisation Using the Vici Venous Stent®

The aim was to assess two year outcomes with placement of the Vici Venous Stent® in patients with chronic iliofemoral venous occlusions (complete blockage). This was a retrospective single centre study comprising patients treated with the Vici Venous Stent for venographically verified iliofemoral venous occlusion and post-thrombotic syndrome (Villalta score≥5 points) at least 12 months after acute deep vein thrombosis. Venography and intravascular ultrasound were used peri-operatively; duplex ultrasound was used to assess stent patency during follow up. Eighty-eight patients (101 limbs) had stent placement between March 2014 and October 2016. Median pre-treatment Villalta score was 14 (range 5-33). Stenting extended across the inguinal ligament in 63 limbs (62%) in order to land in a healthy venous segment. Six patients (7%) required endophlebectomy and fistula creation. Median imaging follow up was 21 months (range 0-41 months). Primary, assisted primary and secondary patency rates at one year were 59%, 78%, and 87%, respectively, and two years 51%, 73%, and 82%, respectively. Forty-three limbs (43%) had re-intervention (lysis, venoplasty, and/or placement of stent) during follow up; median time to re-intervention was 32 days (range 0-520 days). At 24 months, 37 of 53 limbs (70%) with available Villalta assessment showed clinically significant improvement (>30% reduction of baseline score). Villalta scores at the 6, 12, and 24 month clinical follow up were significantly lower than before stenting (p<.001, all time points). In a subset analyses of limbs with stenting terminating above and below the inguinal ligament, secondary cumulative patency rates at 24 months were 90% and 79%, respectively; clinical outcome showed 58% vs. 73% of limbs with clinically significant improvement, respectively. There was no statistically significant difference in patency or clinical outcomes. The Vici Venous Stent is associated with a good secondary patency rate and durable and substantial symptomatic resolution in patients with chronic post-thrombotic occlusions, regardless of whether stents extended beneath the inguinal ligament.

Stent patency in patients with advanced chronic venous disease and nonthrombotic iliac vein lesions

ObjectiveMidterm patency results of iliac vein stents placed for nonthrombotic iliac vein lesions (NIVLs) are not widely known. Previously published studies involving large series of patients with iliac vein stent placement have failed to clearly demonstrate the outcomes for patients with NIVLs and advanced disease. To further study this issue, we reviewed our series of 268 iliac vein stents placed for NIVLs. MethodsRetrospective analysis was performed of 210 patients who underwent common or external iliac vein angioplasty and stent placement procedures between January 2013 and December 2014. Only patients with Clinical, Etiology, Anatomy, and Pathophysiology classification scores of C3, C4, or C5 were included. Patients were excluded if they had either active ulcer disease or signs of post-thrombotic lesions at initial venography or intravascular ultrasound (IVUS). Ultrasound-guided puncture was performed of the femoral or common femoral vein at the discretion of the surgeon. This was followed by ascending venography. IVUS was used in cases in which a definite stenosis was not appreciated on initial ascending venography. Balloon angioplasty and stents were applied across lesions. After the procedure, patients were instructed to use clopidogrel 75 mg daily. Patency of the stents was assessed during a follow-up visit with abdominal venous duplex ultrasound scans. The length of the patients' follow-up and stent patency rates were based on the last previous duplex ultrasound scan available. ResultsA total of 268 procedures were performed in 210 patients. Bilateral lower extremity stent placements were required in 58 patients; 173 (64.6%) procedures were performed in women. The average age of our patients was 72 ± 15 (standard deviation) years. Of the 268 procedures, 144 (53.7%) were performed in the left lower extremity. The Clinical, Etiology, Anatomy, and Pathophysiology classification of lower extremity venous disease was 58%, 30%, and 12% for C3, C4, and C5, respectively. Our average follow-up period was 437 days (median, 499 days; range, 1-1060 days). Patients were observed for >6 months, 1 year, and 2 years in 71.3%, 57.1%, and 28.7% of cases, respectively. During this period, 4 of the 268 (1.5%) limbs experienced in-stent thrombosis. Primary stent patency of 98.7%, 98.3%, and 97.9% was noted at 6 months, 1 year, and 2 years of follow-up, respectively. ConclusionsOur midterm patency rates for iliac vein stents placed in patients with advanced chronic venous disease demonstrated excellent (98.5%) results. Furthermore, with IVUS assistance, we have clearly documented the average area of iliac venous segments as well as the most common locations of the stenoses.

Hematocrit Measurement with R2* and Quantitative Susceptibility Mapping in Postmortem Brain.

Noninvasive venous oxygenation quantification with MR imaging will improve the neurophysiologic investigation and the understanding of the pathophysiology in neurologic diseases. Available MR imaging methods are limited by sensitivity to flow and often require assumptions of the hematocrit level. In situ postmortem imaging enables evaluation of methods in a fully deoxygenated environment without flow artifacts, allowing direct calculation of hematocrit. This study compares 2 venous oxygenation quantification methods in in situ postmortem subjects. Transverse relaxation (R2*) mapping and quantitative susceptibility mapping were performed on a whole-body 4.7T MR imaging system. Intravenous measurements in major draining intracranial veins were compared between the 2 methods in 3 postmortem subjects. The quantitative susceptibility mapping technique was also applied in 10 healthy control subjects and compared with reference venous oxygenation values. In 2 early postmortem subjects, R2* mapping and quantitative susceptibility mapping measurements within intracranial veins had a significant and strong correlation (R2 = 0.805, P = .004 and R2 = 0.836, P = .02). Higher R2* and susceptibility values were consistently demonstrated within gravitationally dependent venous segments during the early postmortem period. Hematocrit ranged from 0.102 to 0.580 in postmortem subjects, with R2* and susceptibility as large as 291 seconds-1 and 1.75 ppm, respectively. Measurements of R2* and quantitative susceptibility mapping within large intracranial draining veins have a high correlation in early postmortem subjects. This study supports the use of quantitative susceptibility mapping for evaluation of in vivo venous oxygenation and postmortem hematocrit concentrations.

Venoarterial communication mediates arterial wall shear stress-induced maternal uterine vascular remodeling during pregnancy.

Although expansive remodeling of the maternal uterine circulation during pregnancy is essential for maintaining uteroplacental perfusion and normal fetal growth, the underlying physiological mechanisms are not well understood. Using a rat model, surgical approaches were used to alter uterine hemodynamics and wall shear stress (WSS) to evaluate the effects of WSS and venoarterial communication (e.g., transfer of placentally derived growth signals from postplacental veins to preplacental arteries) on gestational uterine vascular remodeling. Changes in WSS secondary to ligation of the cervical but not the ovarian end of the main uterine artery and vein provoked significant expansive remodeling at the opposite end of both vessels, but only in pregnant animals. The ≈50% increase in lumen diameter (relative to the contralateral horn) was associated with an upregulation of total endothelial nitric oxide (NO) synthase expression and was abolished by in vivo NO synthase inhibition with N-nitro-l-arginine methyl ester. Complete removal of a venous segment adjacent to the uterine artery to eliminate local venous influences significantly attenuated the WSS-induced remodeling by about one-half ( P < 0.05). These findings indicate that, during pregnancy, 1) increased WSS stimulates uterine artery growth via NO signaling and 2) the presence of an adjacent vein is required for arterial remodeling to fully occur. NEW & NOTEWORTHY This study provides the first in vivo evidence for the importance of venous influences on arterial growth within the uteroplacental circulation.

Evaluating intimal hyperplasia under clinical conditions.

Open arterial revascularization using venous segments is frequently associated with the development of intimal hyperplasia (IH), leading to severe restenosis and graft failure. The lack of treatment to prevent this pathology is a major problem. Therefore, we generated a new porcine model, which closely mimics the clinical development of human IH, to test the therapeutic potential of candidate drugs. A patch of jugular vein was sutured to the right common carotid artery of pigs, to expose the vein to haemodynamic conditions of the arterial bed. Four weeks after surgery, the operated vessels which received no further treatment (the control group) were compared with (i) contralateral, non-operated vessels (the healthy group); (ii) vessels of pigs that received a perivascular application of a drug-free microparticle gel (the placebo group) and (iii) vessels of pigs that perioperatively received the same gel loaded with 10-mg atorvastatin (the atorvastatin group). When compared with non-operated vessels, all operated segments displayed a sizable IH which was thicker in the venous patch than in the host artery. These alterations were associated with a thickening of the intima layer of both vessels in the absence of inflammation. The intima/media ratio has been significantly increased by 2000-fold in the vein patches. Perivascular application of atorvastatin did not prevent IH formation. However, the drug increased the adventitial neovascularization in the operated vessels. The novel porcine model allows for monitoring IH formation under haemodynamic conditions which mimic clinical situations. It should facilitate the screening of innovative treatments to prevent restenosis.

Percutaneous Transhepatic Approach for Recanalization of Superior Mesenteric and Portal Vein in a Patient With Pancreatic Neuroendocrine Tumor Presenting With Bleeding Duodenal Varices: A Brief Case Report

Occlusion of Portal Vein (PV) and Superior Mesenteric Vein (SMV) is a known effect of local infiltration by pancreatic or mesenteric neuroendocrine tumors. Venous occlusion leads to formation of collateral pathways to restore hepatopetal flow in main PV and these collateral pathways can be seen in the form of ectopic (duodenal or jejunal) varices. We present a case of bleeding duodenal varices secondary to SMV occlusion by a locally infiltrating pancreatic neuroendocrine tumor which was successfully treated by coil embolization of varices and SMV stenting of the occluded venous segment after failure of endoscopic glue injection. Various endovascular minimally invasive approaches have been described in literature for recanalization of SMV in such clinical scenarios which maybe challenging to treat for surgical methods. We recommend use of the retrograde transhepatic technique for recanalization of occluded SMV and embolization of associated varices as an alternate treatment option in such scenarios.

Placement of tunnelled hemodialysis catheters across stenotic and occluded central veins.

PURPOSE. The purpose of this study was to evaluate the efficacy of placement of tunneled hemodialysis catheters in patients with occluded or stenotic central veins. MATERIALS AND METHODS. Data were prospectively collected for 26 patients (11 male, 15 female, mean age 52 years) referred for placement of tunneled hemodialysis catheters with central venous stenoses or occlusions. The central venous occlusions or stenoses were recanalized using traditional interventional catheter and guidewire techniques.<br />RESULTS. Thirty central venous access procedures were performed of which 28 (93%) procedures resulted in successful tunneled catheter insertion. Twenty-one internal jugular venous (13 right, 8 left) and 7 subclavian venous (3 right, 4 left) catheters were placed. Eighteen stenotic and 10 occluded venous segments were crossed including the brachiocephalic vein (n = 22), subclavian vein (n = 2), and the superior vena cava (4). One patient required insertion of a metallic stent to facilitate passage of the hemodialysis catheter across an occluded brachiocephalic vein. No procedure-related complications occurred. No episodes of upper extremity swelling or superior vena cava syndrome occurred following catheter insertion.<br />CONCLUSIONS. Insertion of tunneled hemodialysis catheter across occluded or stenotic central veins is technically feasible and safe. The use of occluded or stenotic central veins for catheter access preserves patent central veins for future shunt access.

Altered velocity gradient in lower limb chronic venous disease.

In physiology, velocity of the deep venous compartment is higher than the one in the saphenous compartment which is higher than the one in the tributaries. Considering that velocity variation is associated with changes in the pressure gradient, aim of the present study is to assess changes in venous kinetics in case of superficial chronic venous disease, so to provide further clues in venous drainage direction determination. Venous ultrasound scanning was performed on 40 lower limbs of 28 chronic venous disease patients (C2-6Ep,As,Pr). Velocities were measured in three different venous segments: great saphenous vein at 2 cm above the origin of the incompetent tributary (Group-A). great saphenous vein at 2 cm below the origin of tributary (Group-B). tributary at 2 cm from its origin from the great saphenous vein (Group-C.). Diastolic time average velocity was higher in group-C (-21.3 ± 8.5 cm/s) than in group-A (-15.7 ± 5.2 cm/s; p = .0001) and group-B (-11.1 ± 2.9 cm/s; p = .0001), thus indicating an inversion of the physiological velocity gradient in chronic venous disease patients. Chronic venous disease presents a subverted velocity gradient. These data introduce objective hemodynamics data, paving the way for further investigation in venous drainage direction determination.

Comparison of a Pocket-Sized Versus a Full-Sized Ultrasound System in the Diagnosis of Proximal Lower Limb Acute Deep Vein Thrombosis

This study assessed the performance of a pocket-sized ultrasound system for the diagnosis of proximal lower limb acute deep vein thrombosis (DVT) compared to a full-sized ultrasound system. Patients who needed urgent lower limb sonograms for acute DVT were invited for the study. In each examination, the investigator scanned the patient using the pocket-sized system and then repeated the scan using the full-sized system. The sensitivity, specificity, and accuracy of the pocket-sized system were determined in reference to the full-sized system. The venous segments that failed to be visualized using the two systems were compared. One hundred lower limbs comprising 500 venous segments were examined. There were four venous segments, including two mid and two lower femoral veins in two patients who failed to be visualized using both systems. The sensitivity, specificity, and accuracy for diagnosing proximal lower limb acute DVT were 100% (95% confidence interval [CI], 94.94%–100%), 100% (95% CI, 99.05%–100%), and 100% (95% CI, 99.19%–100%), respectively. The pocket-sized ultrasound system and the full sized-ultrasound system demonstrated a comparable performance in detecting acute DVT in the leg.

Distinct Vascular Remodeling Pattern of Adult Rats with Carotid-Jugular Shunt

Previous research has revealed that patent vein grafts lose their venous identity Eph-B4 but do not gain arterial identity ephrin-B2 during adaptation to the arterial circulation, and vascular identity marker, for example, the Eph-B4 signaling is a critical determinant of venous wall thickness of vein grafts. But what is the remodeling pattern, especially the remodeling pattern of vascular identity in the venous segment of arteriovenous shunt at a late stage postoperation has not been fully explored. This study was conducted to characterize the remodeling pattern of shear stress, vascular identity, structural composition and morphology, and transcriptional profiles in jugular segment of carotid-jugular (CJ) shunt and/or pulmonary artery (PA), which delivers an increased amount of mixed blood at a late stage postoperation in adult rats. CJ shunt was created in adult Wistar rats via end-to-end anastomosis of carotid artery (CA) and jugular vein (JV). At the time of 15weeks, after hemodynamics test, remodeled jugular segment of CJ shunt, PA, and sham-operated corresponding vessels were isolated. Reverse transcription polymerase chain reaction, microarray, western blot, immunohistochemistry experiments, and morphology analyses were performed. CJ shunt shear stresses have been patterned to some sort of balance with no significant difference in shear stress between carotid segment and jugular segment (P>0.05). Immunohistochemical analysis reveals that venous identity marker Eph-B4 is lost, but arterial identity markers ephrin-B2 and regulator of G-protein signaling 5 are gained in jugular segment of CJ shunt (P<0.01), and these 2 arterial identity markers further strengthened in PA (P<0.01) in shunted rats compared with controls. Jugular segment of CJ shunt undergoes significant intimal hyperplasia with strong expression of smooth muscle cell markers (P<0.05) and demonstrates a distinct transcriptional profiles which reveals that transcripts of 5 arterial markers are significantly upregulated (P<0.05 or<0.01) compared with sham-operated JV; among them, G-protein signaling 5 is exactly the gene with the largest fold change (10.14-fold) in all genes tested by microarray experiment. Venous identity is lost, but arterial identity is gained in jugular segment of CJ shunt and arterial identity further strengthened in PA in adult shunted rats during late adaptation.

3:27 PM Abstract No. 354 Update on the Cook VIVO clinical study: a multicenter evaluation of the Zilver vena venous stent in the treatment of symptomatic iliofemoral venous outflow obstruction

The purpose of this prospective, global, single-arm, investigational study is to evaluate the safety and effectiveness of the Zilver Vena Venous Stent in the treatment of patients with symptomatic iliofemoral venous outflow obstruction. Symptomatic patients with venous outflow obstruction in a single iliofemoral venous segment underwent treatment with the Zilver Vena Venous Stent (Cook Medical, Limerick, Ireland). The primary study endpoints are: 30-day primary safety endpoint (freedom from major adverse events) and 12-month primary effectiveness endpoint (primary quantitative patency). 243 patients (70% female; 82% white; mean age of 53 ± 15 years) were enrolled at 30 institutions; study enrollment is complete and patient follow-up is ongoing with data collection out to 36 months. The site-reported indications for stent placement included (note: a single patient may have multiple indications): iliac vein compression by the iliac artery (n = 190; 78%), stenosis due to chronic post-thrombotic obstruction (n = 71; 29%), stenosis after treatment for acute deep vein thrombosis (n = 37; 15%), iatrogenic stenosis (n = 2; 0.8%), extrinsic compression from a mass (n = 2; 0.8%), or other indications (n = 12; 5%). Based on site-reported data, most lesions (n = 209; 86%) affected the vein(s) of the left iliofemoral venous outflow tract. The treated vessel segments included: common iliac vein (n = 216), external iliac vein (n = 148), common femoral vein (n = 66), and femoral vein (n = 7). Enrollment in the VIVO Study is complete, with clinical and imaging follow-up data collection ongoing. An updated study status will be presented, including final baseline patient and lesion characteristics and procedural outcomes.

MicroRNA-155 promotes neointimal hyperplasia through smooth muscle-like cell-derived RANTES in arteriovenous fistulas

ObjectiveArteriovenous fistula (AVF) suffers from a high number of failures caused by insufficient outward remodeling and venous neointimal hyperplasia formation. The aim was to investigate the exact mechanism by which microRNA-155 (miR-155) in the outflow vein of AVF is regulated. MethodsAVFs between the branch of the jugular vein and carotid artery in an end-to-end manner were created in C57BL/6 and miR-155−/− mice with a C57BL/6 background. The venous segments were harvested at day 7, 14, 21, and 28, and the AVFs were analyzed histologically and at a messenger RNA level using real-time quantitative polymerase chain reactions. The outflow vein of AVF and the normal great saphenous vein, collected from patients with chronic kidney disease and coronary artery bypass surgery, were analyzed by histologic and molecular biologic approaches. ResultsVenous neointimal hyperplasia is significantly alleviated in miR-155−/− mice, and the expression of several chemokines and cytokines in the vessel wall, including regulated on activation, normal T-cell expressed and secreted factor (RANTES), monocyte chemoattractant protein 1, and vascular endothelial growth factor, was inhibited. miR-155 promoted the RANTES expression of smooth muscle-like cells, which in turn facilitated cell proliferation and extracellular matrix production. ConclusionsmiR-155 enhances venous neointima formation through the autocrine and paracrine effects of smooth muscle-like cell-derived RANTES in a nuclear factor κB-dependent manner during the entire AVF process, especially at the advanced stage.

The infraclavicular approach for Paget–Schroetter syndrome

Introduction Paget-Schroetter syndrome is a rare effort thrombosis of the axillary-subclavian vein, mainly occurring in young male patients. Current management involves immediate catheter directed thrombolysis, followed by surgical decompression of the subclavian vein. This has been invariably performed using a transaxillary or supraclavicular approach. However, the subclavian vein crosses the first rib anteriorly just behind the manubrium and can also be accessed via an infraclavicular incision. Methods MEDLINE® and Embase™ were searched for all studies on outcomes in patients undergoing infraclavicular first rib resection for treatment of Paget-Schroetter syndrome. Measured outcomes included freedom from reintervention, secondary patency and symptom resolution. Studies on neurogenic, arterial and iatrogenic venous thoracic outlet syndrome were not included. Findings Six studies (involving 268 patients) were eligible. The overall secondary venous patency rate was 98.5%. There was freedom from reintervention in 89.9% of cases and among those patients with reocclusion, 84.0% had chronic thrombosis (symptom duration >14 days), with 76.2% having a venous segment stenosis of >2cm. Only 3 of the 27 patients remained occluded despite reintervention. The infraclavicular approach provides excellent exposure to the subclavian vein and allows reconstruction when required. Moreover, this approach enables complete resection of the extrinsic compression that precipitated the initial thrombotic event, with excellent long-term patency rates. In conclusion, the infraclavicular route may have significant advantages compared with the transaxillary or supraclavicular approaches for successful and durable treatment of Paget-Schroetter syndrome.

Towards multi-phase postmortem CT angiography in children: a study on a porcine model.

Multi-phase postmortem computed tomography angiography (MPMCTA) is a growing technique, which is standardized for adults. Application of this protocol for a children population is not so well defined. Our study aims to adapt the adult's protocol to children, using a porcine model. Three groups of 18 pigs were studied, with a weight distribution between 4 and 48kg. Different pump devices were used. Pigs of group I were studied using the Virtangio® machine, whereas pigs of groups II and III were studied using used the Medrad® machine. Study of vascular opacification was possible using a semi-quantitative method based on 26 arterial and 26 venous segments that were distributed over the entire body from the cephalic extremity to the posterior pawns. While thoracic, abdominal, and pelvic vascular opacification were complete for each individual pig in a group, group III showed better vascular opacification for the cephalic extremity. This was also true for anterior and posterior pawns vascular opacification. Spearman correlation tests showed a significant relationship between anthropometric characteristics of pigs, injection parameters, and percentage of opacified segments. A higher percentage of opacification was obtained for individuals of lower weights, with comparatively lower quantities of contrast agent injected. Postmortem computed tomography angiography (PMCTA) was possible for all the individuals, particularly for small weights (4kg) using the Medrad® machine. However, further studies are needed to better understand the procedure.

Viabahn stent for hemodialysis shunt: efficacy, long segment recanalization and prognostic factors for reintervention.

The study evaluated the Heparin Bioactive Surface (HBS) Viabahn Stent (W.L. Gore & Associates, Flagstaff, Arizona) efficacy in the maintenance or re-establishment of hemodialysis. Fifty HBS Viabahn stents deployed in 37 consecutive patients with hemodialysis dysfunction from January 2008 to May 2016 were evaluated in a single-institution retrospective review. Outcomes were stent patency intended as primary circuit patency (PP), assisted primary patency (APP), target lesion primary patency (TLPP) and secondary patency (SP). Moreover, the risk factor analysis for hemodialysis dysfunction that required reintervention was performed. A subgroup analysis was conducted to assess patency of Viabahn stent to treat peripheral venous long segment obstruction (LSO). Overall Kaplan-Meyer PPs were 60% at 12 months and 42% at 24 months. Overall TLPP estimated rates were 68% and 49% at 12 and 24 months, respectively. The corresponding SP rates were 85% and 78% at the same period. Estimated PP rates at 12 and 24 months for stent placement after peripheral venous long segment recanalization procedure were 53% and 31%, respectively. Corresponding SP rates were 82% and 68%, respectively. The APP rates were 79% at 12 months and 61% at 24 months. Female sex, access age and thrombosis were associated with reduced primary patency. Considering the high rates of PP, TLPP, APP and SP, Viabahn stents have been proven effective in maintaining or re-establishing the hemodialysis access. Moreover, stent placement after recanalization of LSO of venous out-flow represented a valid approach to rescue a dysfunctional fistula that would otherwise be abandoned.

Usefulness of preoperative venography in patients with cardiac implantable electronic devices submitted to lead replacement or device upgrade procedures.

BackgroundVenous obstructions are common in patients with transvenous cardiac implantable electronic devices, but they rarely cause immediate clinical problems. The main consequence of these lesions is the difficulty in obtaining venous access for additional leads implantation.ObjectivesWe aimed to assess the prevalence and predictor factors of venous lesions in patients referred to lead reoperations, and to define the role of preoperative venography in the planning of these procedures.MethodsFrom April 2013 to July 2016, contrast venography was performed in 100 patients referred to device upgrade, revision and lead extraction. Venous lesions were classified as non-significant (< 50%), moderate stenosis (51-70%), severe stenosis (71-99%) or occlusion (100%). Collateral circulation was classified as absent, discrete, moderate or accentuated. The surgical strategy was defined according to the result of the preoperative venography. Univariate analysis was used to investigate predictor factors related to the occurrence of these lesions, with 5% of significance level.ResultsModerate venous stenosis was observed in 23%, severe in 13% and occlusions in 11%. There were no significant differences in relation to the device side or the venous segment. The usefulness of the preoperative venography to define the operative tactic was proven, and in 99% of the cases, the established surgical strategy could be performed according to plan.ConclusionsThe prevalence of venous obstruction is high in CIED recipients referred to reoperations. Venography is highly indicated as a preoperative examination for allowing the adequate surgical planning of procedures involving previous transvenous leads.

Detection of Lower Limb Deep Vein Thrombosis: Comparison between Radionuclide Venography and Venous Ultrasonography.

Deep vein thrombosis (DVT) is a serious medical condition that needs prompt diagnosis and treatment. The invasive gold standard contrast venography has largely been replaced by venous ultrasonography which is currently the imaging modality of choice for DVT diagnosis. Radionuclide venography (RNV) is an alternative test for DVT, but a few studies have directly compared RNV with venous ultrasonography. This study aims to determine the agreement between RNV and venous ultrasonography for diagnosis of DVT and to determine the predictive value of different RNV findings for the prediction of DVT as detected by venous ultrasonography. Imaging results from patients who underwent both RNV and venous ultrasonography for suspected DVT no more than 1 week apart were reviewed. Results from both modalities were compared to determine inter-modality agreement. A total of 121 venous segments from 102 lower limbs of 75 patients could be compared. The prevalence of DVT as detected by venous ultrasonography was 39%. RNV and venous ultrasonography had moderate agreement (73.6% agreement, κ =0.48, P < 0.0001). The absence of radiotracer activity from a deep venous segment had a positive predictive value (PPV) of 100% for DVT. Other findings such as isolated great saphenous vein activity had a lower PPV. The negative predictive value of RNV is 97.5% with only one patient out of forty with normal RNV found to have DVT by venous ultrasonography, which suggests that DVT can virtually be excluded in patients with normal RNV.

Thromboembolic disease - Etiological factors and diagnostic approach

Background: The aim of the article was to define etiological factors for the occurrence of thromboembolism venous and arterial segments and preview of the sensitivity and specificity of diagnostic procedures in the treatment algorithm. Patients and Methods: The study included 60 patients during the 4-year period. The patients are classified into two groups according to the type of thromboembolism, in the group under the diagnosis of venous thromboembolism and group under the diagnosis of arterial thromboembolism. Results: Statistical analysis showed that arterial thromboembolisms occurred statistically significant later in comparison to venous (t = 4.0969; P = 0.0001). The mortality relationship with all analyzed parameters (age, erythrocytes, hemoglobin, platelets, gender, D-dimer, fibrinogen, immobility, veins surgery, pregnancy, smoking, orthopedic trauma, neoplasms, and pulmonary embolism) showed that statistically significant association was observed only in the case of pulmonary embolism. Conclusion: Biochemical parameters of the blood of patients; red blood cell count, hemoglobin concentration, and platelet counts in the study conducted showed a positive relationship with the occurrence of venous thromboembolism while D-dimer and fibrinogen present in increased values in most patients with venous and arterial thromboembolism. Pulmonary embolism directly affects the outcome of patients with thromboembolic diseases taking into account that in the study conducted in venous thrombosis complicated pulmonary embolism resulted in deaths.

Outcomes Following Placement of Venous Stents for Treatment of Thrombotic Venous Disease

BackgroundEndovenous stenting is a method to overcome venous outflow obstruction in the treatment of patients with acute iliofemoral deep vein thrombosis (DVT) or in those with symptomatic post-thrombotic syndrome (PTS). These treatments allow maximal luminal expansion of the caval and/or iliac venous segment leading to a reduction in venous hypertension. While there is growing enthusiasm for their use, particularly as conventional treatments usually with anticoagulation are not always effective there is however little clinical data regarding efficacy in improving clinical outcome.ObjectivesTo determine the outcomes in patients following placement of venous stents for treatment of obstruction in acute venous thrombotic and post-thrombotic syndrome.MethodsConsecutive patients with a history of DVT in whom a venous stent was inserted at two UK specialist tertiary referral centres between 2012-2015 were included. ‘Acute’ patients consisted of those with a fresh symptomatic iliofemoral DVT; chronic patients were those with recalcitrant PTS unresponsive to conventional therapy. Patients planned for intervention were discussed by a multidisciplinary team made up from Haematology, Interventional Radiology and Vascular Surgery.Stents were placed under general anaesthesia. Venous access was obtained using ultrasound guidance. Intravascular ultrasound (IVUS) was used to size the stent and to ensure it was fully expanded. Endophlebectomy with arterio-venous fistula formation was carried out in selected patients. All patients were given therapeutic dose low molecular weight heparin (LMWH) post procedure before transition to oral anticoagulation.Ultrasound surveillance commenced the day after the procedure and at 2 weeks, 6 weeks, 3 months, 6 months, 1 year and annually thereafter. Clinical follow-up was at 6 weeks, 6 monthly thereafter. Primary patency was defined as a patent stent with <50% diameter reduction. Primary-assisted patency was defined as a stent that had not occluded, but had required a re-intervention to maintain patency, based on imaging findings and/or symptoms. Secondary patency included stents that had blocked and were successfully re-opened. Ulcer healing or changes in Villalta Score were used as measures of clinical outcome following intervention.Results379 venous stents were placed in 148 patients. The median age of patients was 42yrs (range: 18-81yrs), and 86 (58%) patients were female. Symptoms in the left leg were most common (116 patients, 78%).There were 60 (41%) patients who had a venous stent placed to treat an underlying stenosis following catheter directed thrombolysis of an acute iliofemoral DVT. 88 (58%) patients had stent placement to treat a post-thrombotic obstruction considered pathological for PTS.Primary, primary-assisted and secondary patency was 67%, 85% and 88% respectively at one-year in the acute DVT group (figure 1) and 64%, 86% and 86% respectively for the PTS group (figure 2). The median Villata score was 0 (range 0-14), 12 months after stenting, though new ulceration was noted in three patients in the acute DVT group. Median Villalta scores in patients without ulceration decreased from 15 (range 6-23) to 5 (range 1-22) one-year following the procedure (P<0.0001) in the PTS group with the greatest improvement in Villalta score in patients with a patent stent (P<0.0001). Ulcer healing occurred in 6 of 13 patients during follow-up. Four patients with severe pre-operative PTS developed an ulcer six-months following intervention.There was one death from cancer during follow-up, but no stent related mortality or major bleeding complications.ConclusionsThis is the largest reported series of outcomes of venous stents placed in patients with acute iliofemoral venous thrombosis or severe post-thrombotic syndrome. Patients had a minimum follow-up of one year Venous stenting offer potential for the treatment of patients with obstruction related to thrombotic venous disease with good clinical outcomes at one year. Further study on patient selection, outcomes and optimal anticoagulation is required. [Display omitted] DisclosuresBreen:Veniti: Speakers Bureau. Cohen:Bayer Healthcare: Employment, Speakers Bureau. Uprichard:Bayer Healthcare: Speakers Bureau. Black:Veniti: Speakers Bureau.

Microcirculatory parameters in compensated and decompensated type 2 diabetes mellitus

To reveal the features of microcirculatory parameters in compensated and decompensated type 2 diabetes mellitus (T2DM). A total of 196 patients with T2DM were examined and divided into 2 groups: 1) 52 patients (40.4% of men) aged 52.8±8.7 years with compensated T2DM (glycated hemoglobin (HbA1с), 6.3±0.5%); 2) 68 patients (38.2% of men) aged 52.8±8.1 years with decompensated T2DM (HbA1с, 9.4±1.7%). Both patient groups had concomitant hypertension (its prevalence, degree, stage of hypertension were comparable). A control group consisted of 76 volunteers (40.8% of men) aged 52.2±8.7 years with normal carbohydrate metabolism and without signs of cardiovascular disease (HbA1с, 5.3±0.49%). Capillary blood flow in the finger nail-fold area was investigated in all the participants. A digital optical capillaroscope with image-processing software was used to obtain quantitative blood microcirculatory parameters. The diameters of arterial and venous capillary segments were measured, by calculating the remodeling rate. The degree of capillary tortuosity, network density, and polymorphism and the size of the perivascular zone (PZ) were estimated. Blood rheological properties and capillary blood flow velocity were also investigated. The decompensated T2DM group compared to the compensated T2DM group was found to have a narrowing of the arterial capillary segment diameter (8.4±2.0 µm; p=0.009) and an increase in remodeling rates (1.47±0.22; p=0.000). The tendency of the PZ size to be larger in patients with decompensated T2DM compared to those with compensated T2DM (p=0.080) and the increase in this indicator compared to the control group (p=0.001) reflect the presence of edema syndrome in Group 2, as laboratory confirmed by a statistically significantly elevated sodium level (p=0.000; p=0.006). The enlarged venous capillary segment demonstrates involvement of the venous component in microcirculatory disorders in T2DM. The reduction in the density of the capillary network and the increase in capillary tortuosity and polymorphism, which were also observed in the patients of both groups versus the control group, are referred to as disorders that are characteristic of T2DM. In decompensated T2DM, capillary bed structural and functional changes are found as a narrowing of the arterial capillary segment, an increase in the rate of remodeling, and enlargement of the PZ. Digital capillaroscopy opens up new possibilities for assessing the magnitude of changes in the microcirculatory system in DM and can simultaneously evaluate the efficiency of treatment, by monitoring the status of the microvasculature.