Central Vein Stenosis Research Articles

MO767CENTRAL VEIN STENOSIS: FROM DIAGNOSTICS TO TREATMENT STRATEGY

Abstract Background and Aims To analyze the screening and prognostic value of various diagnostic signs of central vein stenosis (CVS). Method The retrospective study included 549 patients with AVF/AVG dysfunction. 211 patients were diagnosed with CVS, other patients had lesions of peripheral venous segments. In case of vascular access dysfunction, patients were examined according to the local protocol: ultrasound examination of peripheral (to exclude damage of the peripheral AVF segments) and central veins (at an accessible length) was performed, followed by CT angiography or percutaneous angiography, if necessary. Results Among various clinical signs only limb edema and dilated veins on the chest demonstrated high sensitivity. Aneurysmal dilatation of an AVF was more common in peripheral lesions (CVS RR<1). It should be considered that the clinical signs itself are more likely to be associated with the peripheral lesion than CVS (high NPV value) – table 1. “Indirect dialysis signs” also have very low screening efficacy (Se and Sp) and prognostic values – table 2. Ultrasound signs have low screening accuracy, but high prognostic values. In other words, in the presence of ultrasound signs, patient is likely to have CVS with high probability – table 3. When comparing the frequency of correct and incorrect classifications for different types of lesion, ultrasound accuracy exceeds the clinical picture for types of lesion 1C and 1D (according to the types of lesion in Society of Interventional Radiology Reporting Standards for Thoracic Central Vein Obstruction, doi: 10.1016/j.jvir.2017.12.013): RR= 3,433 [95% CI 2,074; 6,132], p<0.0001 and RR= 2,538 [95% CI 1,592; 4,265], p<0.0001, respectively, but not for lesion types 2B and 3: RR=1.583 [95% CI 0.935; 2.779], p=0.0883 and RR=1 [95% CI 0.231; 4.325], p >0.9999, respectively. In total, incorrect CVS type classifications is noted in 30.7% of cases when using ultrasound imaging. CT angiography and percutaneous angiography are almost 100% effective in the diagnosis of CVS. However, CT angiography is not always informative when AVF is functioning and the volume blood flow is high. In turn, percutaneous angiography does not always allow to assess the condition of the veins of the contralateral side. At the same time, correct detection of lesion type is pivotal to determine the future strategy of providing the patient with permanent vascular access. For example, the patient has very little chance to get functional AVF in case of with two-sided subclavian vein stenosis. Conclusion The CVS diagnostics should be comprehensive, using different methods for screening, confirming CVS and determining of it type.

MO770BARE METAL STENTS IN HD PATIENTS WITH CENTRAL VEIN STENOSES: TO STENT OR NOT TO STENT, THAT IS THE QUESTION

Abstract Background and Aims According to the current KDIGO guidelines, angioplasty should be preferred procedure for treatment of CVS instead of the bare metal stents or self-expanding stent-grafts placement. However, bare stents are still significantly more affordable than stent grafts. Aim: comparative analysis of the results of isolated balloon angioplasty (BA) and combined technique (BA with a stent placement in HD patients with central vein stenosis (CVS). Method A retrospective study included 62 patients with functional AVF and confirmed CVS: subclavian, brachiocephalic veins, vena cava inferior, or multiple lesions. In 39 patients, stents were not used; isolated balloon angioplasty (BA) was performed. In 23 patients we used bare metal stents during the first endovascular treatment. Results The use of stents leads to increase of primary patency (the time interval between the first and second endovascular interventions) – fig. 1A; HR (BA only vs. stenting) 2.064 [95% CI 1.252; 3.404], p = 0.0017. The use of stents allows to increase secondary patency (the time interval between the first endovascular intervention and the complete cessation of the use of AVF): HR=2.03 [95% CI 1.232; 3.347], p = 0.0021; fig 1B. Total need for surgical interventions did not differ: BA only 1.511 [95% CI 1.225; 1.843] and BA+stenting 1.277 [95% CI 0.997; 1.611] per 10 patient-months, incidence rate ratio 1.183 [95% CI 0.872; 1.612] p=0.2822. The second isolated BA allowed to increase patency compared to the first (HR of AVF function loss or relapse 0.512 [95% CI 0.32; 0.818], log rank p=0.001), and the third compared to the second isolated BA (HR=0.607 [95% CI 0.384; 0.959], log rank p=0.0157). The fourth isolated BA also showed a slight increase in AVF patency, but in this case we observed no significant difference with the previous intervention (HR= 0.783 [95% CI 0.501; 1.225], log rank p=0.2433). In the case of BA+stenting, the second intervention, which was consisted of stent recanalization, allowed to increase patency of the AVF (HR= 0.433 [95% CI 0.231; 0.813], log rank p= 0.0014), but the third intervention was no longer accompanied by a significant increase in patency (HR= 0.873 [95% CI 0.489; 1.558], log rank p= 0.629) and AVF function was completely lost. Conclusion The use of stents leads to a moderate increase in the median patency of AVF and a significant increase in the proportion of patients with functional AVF in the long-term period. However, repeated surgeries are significantly less effective than in a case of isolated BA. Therefore, we consider isolated BA to be the optimal treatment strategy, and stenting should be used only if the isolated BA does not result in clinical improvement. Multiple endovascular interventions can extend the duration of AVF functioning, however, in our study, AVF function was completely lost up to 52 months after the clinical manifestation of CVS in all patients. Thus, isolated BA and BA combined with a bare metal stent placement cannot be considered as a definitive treatment of CVS. Endovascular interventions provide only the necessary amount of time to create vascular access on the contralateral side or for shift of modality of renal replacement therapy.

Abstract No. 136 Evaluation of complications associated with tunneled vascular access lines in pediatric patients

Tunneled vascular access lines are often placed in pediatric patients for long-term vascular access. However, they can be associated with infection, thrombosis, and central vein stenosis, and have been associated with higher mortality rates. The goal of this study is to evaluate complication rates and outcomes in pediatric patients. Retrospective chart review was undertaken after local institutional review board approval on patient ages one month through 22 years who underwent image-guided tunneled line placement between January 1, 2008, and August 1, 2019, at a tertiary academic pediatric hospital. Subjects were randomly selected from this time period, and clinical, procedural, immediate and long-term complications, and outcome variables were collected and evaluated for the duration of each line placement. A random sample of 260 patients, totaling of 738 tunneled vascular lines were evaluated. Subjects had an average number of 2.43 (SD 2.13) lines placed. Patients were nearly evenly split between males (n = 132, 51%) and females (n = 127, 49%). The average age was 7.86 (SD 5.98) years. The majority of placements were for chemotherapy (n = 555, 75.3%). Over half of the lines were totally implanted vascular access devices (TIVAD) (n = 415, 56.5%). 81% (n = 593) lines were placed on the right side. Only six (1.3%) of all placements had complications with the first 48-hours of placement, including 3 (2.8%) polyurethane tunneled cuffed central venous catheters (PTCCVC) (1 bleed, 1 dislodged, 1 infected) and 3 (7.9%) pheresis catheters (2 bleeds and 1 dislodged). The average time to complication in these patients was 0.67 days (SD = 0.52). Late complications, or those that happened after 48 hours of placement, occurred in 152 (34.2%) of lines and majority were due to infection (75%). Infections rates were highest in PTCCVC (n = 47, 25.1%) and tunneled central lines (n = 6, 19.4%). A little over one-third of the complications were rated A or B utilizing the Society of Interventional Radiology complications scale (n = 61, 40.2%), meaning patients required either no therapy or nominal treatment with no consequences and overnight hospital stay. Late complications after 48-hours in tunneled lines are more frequent than earlier, with infections being the most common type, particularly in PTCCVC and tunneled central lines. This may be due to the immunocompromised nature of patients receiving these lines for chemotherapy. Complications often result in line removal and/or antibiotic therapy. Pheresis catheters appear to have the lowest complication rate in the pediatric population.

Cardiac Implantable Electronic Devices in Hemodialysis and Chronic Kidney Disease Patients-An Experience-Based Narrative Review.

Cardiovascular implantable electronic devices (CIEDs) are a standard therapy utilized for different cardiac conditions. They are implanted in a growing number of patients, including those with chronic kidney disease (CKD) and end-stage kidney disease (ESKD). Cardiovascular diseases, including heart failure and malignant arrhythmia, remain the leading cause of mortality among CKD patients, especially in ESKD. CIED implantation procedures are considered minor surgery, typically with transvenous leads inserted via upper central veins, followed by an impulse generator introduced subcutaneously. A decision regarding optimal hemodialysis (HD) modality and the choice of permanent vascular access (VA) could be particularly challenging in CIED recipients. The potential consequences of arteriovenous access on the CIED side are related to (1) venous hypertension from lead-related central vein stenosis and (2) the risk of systemic infection. Therefore, when creating permanent vascular access, the clinical scenario may be complicated by the CIED presence on one side and the lack of suitable vessels for arteriovenous fistula on the contralateral arm. These factors suggest the need for an individualized approach according to different clinical situations: (1) CIED in a CKD patient; (2) CIED in a patient on hemodialysis CIED; and (3) VA in a patient with CIED. This complex clinical conundrum creates the necessity for close cooperation between cardiologists and nephrologists.

Venous stent versus conventional stent for the treatment of central vein obstruction in hemodialysis patients: a retrospective study

Endovascular treatment is a first-line treatment for upper thoracic central vein obstruction (CVO). Few studies using bare venous stents (BVS) in CVO have been conducted. To evaluate the treatment performance of upper thoracic central vein stenosis between BVS and conventional bare stent (CBS) in hemodialysis patients. Hemodialysis patients with upper thoracic central vein obstruction who underwent endovascular treatment at the interventional unit of our institution from 1 January 2008 to 31 December 2018 were enrolled in the present study. CBS was used to treat central vein obstruction in 43 patients and BVS in 34 patients. We compared the primary patency rates and complications between the two stent types. P values < 0.05 were considered statistically significant. The patient demographic data between the CBS and BVS groups were similar. The characteristics of the lesions, procedures, and complications were not significantly different between the two groups (P > 0.05). There were no statistically significant differences of primary patency rates at three and six months between the BVS and CBS groups (94.1% vs. 86.0% and 73.5% vs. 58.1%, respectively; P > 0.05). The primary patency rate at 12 months in the BVS group was significantly higher than that in the CBS group (61.8% vs. 32.6%; P = 0.008). Endovascular treatment of central vein obstruction with BVS provided a higher primary patency rate at 12 months than CBS.

Role of Central Venography Prior to Vascular Access Surgery

Purpose and Objective: Central vein stenosis is not uncommon in renal patients who are on dialysis. Performing new arterio-venous fistula (AVF) in patients with central vein stenosis can lead to significant problems, ultimately leading to loss of AVF. The aim of this study was to assess the role of central venogram before the creation of a new AVF. Materials and Methods: All patients who underwent central venogram before AVF surgery between September 2017 and June 2019 were included in the study. The medical records and central venogram images were reviewed. Data regarding demographics, indication, findings of venogram, arterio-venous access performed, were collected using an online database. Results: A total of 143 patients met the inclusion criteria. The mean age was 52.25 (range 23–86 years) and 85 were men (59.44%). One hundred and thirty-nine out of 143 (97.2%) patients were on dialysis and had a history of ipsilateral and/or contralateral central vein catheterization. However, only 18 of 143 (12.58%) had central vein symptoms. The most common indication was being a precious fistula or last access option (64 patients; 44.75%). Central venogram identified ipsilateral abnormality in 52 patients (36.36%) and contralateral abnormality in 46 patients. Preoperative plan was changed in 24 patients (16.78%) due to venogram findings. Conclusions: This study highlights that central vein stenosis/occlusion can exist in renal dialysis patients even without obvious clinical signs and symptoms. Routine use of diagnostic central venogram in such high-risk patients can identify central vein problems preoperatively and prevent postoperative complications.

Ferumoxytol-enhanced MR Venography of the Central Veins of the Thorax for the Evaluation of Stenosis and Occlusion in Patients with Renal Impairment.

To assess the diagnostic performance of ferumoxytol-enhanced MR venography for the detection of thoracic central vein stenosis or occlusion with conventional venography as the reference standard. In this retrospective study, consecutive patients from May 2012 to December 2018 underwent dedicated ferumoxytol-enhanced MR venography of the thoracic central veins and conventional venography within 6 months for detecting central venous stenosis. The central veins were divided into seven segments for evaluation. MR venography images were evaluated by three radiologists for presence of stenosis or occlusion. Interobserver agreement was assessed using Fleiss κ. A total of 35 patients were included (mean age, 49 years; age range, 12-75 years; 18 females). Of the 122 total venous segments with corresponding conventional venography, 73 were stenotic or occluded. The sensitivity and specificity for detection of stenosis or occlusion was 99% and 98%, respectively. The sensitivity and specificity for detecting occlusion alone was 96% and 98%, respectively. MR venography readers demonstrated moderate agreement in their ability to grade stenosis or occlusion (κ = 0.59). There were no adverse events related to contrast agent administration. Ferumoxytol-enhanced MR venography demonstrated excellent sensitivity and specificity for detection of thoracic central vein stenosis or occlusion.© RSNA, 2020See also the commentary by Finn in this issue.

Association of diabetes, education level, and care dependency with use of temporary vascular access in patients with chronic kidney disease

Temporary vascular access (TVA) is frequently used during the first dialysis in patients with chronic kidney disease (CKD), and it is associated with an increased risk of infection, central vein stenosis, and mortality. Here, factors associated with TVA in patients with CKD were explored. This study included patients in a single-center CKD care program who initiated long-term renal replacement therapy. The primary outcome was TVA use at first dialysis. Factors possibly associated with TVA use were analyzed using Cox regression. Temporary vascular access was used in 53.2% of the patients at first dialysis. In total, 73.2% (n=865) and 26.8% (n=317) of the patients were on hemodialysis and peritoneal dialysis, respectively. Multivariate Cox regression analysis showed that TVA use in patients with CKD was associated with diabetes (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.28-1.81, p<0.001), lower albumin (HR 0.82, 95% CI 0.75-0.91, p<0.001), lower education level (HR 0.75, 95% CI 0.56-1.00, p=0.055), and total care dependency (HR 1.92, CI 1.44-3.43, p=0.003). Diabetes, education level, and care dependency are associated with TVA at dialysis initiation in patients with CKD.

Effect of Treatment According to Intervention Modality with Central Vein Stenosis in Hemodialysis Patients

Effect of Treatment According to Intervention Modality with Central Vein Stenosis in Hemodialysis Patients

THE PATH OF LEAST RESISTANCE: CHRONIC INDWELLING CATHETER COMPLICATIONS OF FIBRIN SHEATH FORMATION IN A PATIENT WITH PERICARDIAL COLLATERALIZATION

SESSION TITLE: Medical Student/Resident Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pericardial collateralization and extrapulmonary shunting due to coexistent superior vena cava (SVC) and inferior vena cava (IVC) fibrin sheaths is rare but should be considered in patients with hypotension and hypoxemia with history of vascular catheterization. CASE PRESENTATION: A 33 year old male with end stage renal disease due to congenital kidney disease and chronic hypotension was admitted with recurrent falls. Vital signs showed marked hypotension and hypoxemia requiring vasopressor support and high flow oxygen. No facial plethora or extremity edema was seen on exam. Laboratory testing did not reveal leukocytosis or metabolic abnormalities. Non-invasive hemodynamic monitoring was indicative of distributive and mild cardiogenic shock. CT thorax showed a right lobar consolidate and an occluded proximal SVC with prominent pericardial collateral vessels. CT abdomen and pelvis demonstrated a long tubular intravascular opacity, which was possibly a fibrin sheath from the IVC into the right common femoral vein. Echocardiogram bubble study revealed left sided bubbles that appeared first before right sided bubbles reflective of intracardiac versus intrapulmonary shunt. The patient was treated for pneumonia and weaned off vasopressors in anticipation of possible cardiothoracic surgery. DISCUSSION: Venous stenoses are sequela of central venous hemodialysis catheter access in 41% of dialysis patients (2). We postulate that prior indwelling dialysis catheter placement in this patient contributed to fibrin sheath formation. As a result, a right to left shunt may have arisen with associated pericardial collateral circulation, contributing to hypoxemia through shunt physiology. This may have chronically impeded preload to the right heart, thus lowering stroke volume and cardiac output. The extent of collateralization was not fully seen on imaging, but it is possible some portion of venous return is bypassing the heart entirely and contributing to hypotension. Among the reported cases of patients with systemic-to-pulmonary collateral vessel circulation and shunt, the involvement of both the SVC and IVC has not been characterized (1). Furthermore, reports of patients with collateral pathways from prior catheters and shunts show good hemodynamics in stark contrast to our case (3). CONCLUSIONS: Chronic indwelling dialysis catheter use can result in fibrin sheath formation in the vessel, leading to stenoses of the SVC and IVC. In turn, pericardial circulation can develop which then functions as a right to left shunt. This is potentially the etiology of hypoxia or hypotension in our patient. This should be recognized as one of the complications of long-term indwelling catheters in the SVC or IVC. Reference #1: Kapur, S. et.al. “Where There is Blood, There is a Way: Unusual Collateral Vessels in Superior and Inferior Vena Obstruction” RadioGraphics 2010; 30:67-78 Reference #2: MacRae JM, Ahmed A, Johnson N, et al. “Central vein stenosis: a common problem in patients on hemodialysis”. ASAIO J. 2005;51:77–81. doi: 10.1097/01.MAT.0000151921.95165.1E Reference #3: Gamet A, et.al. “Acquired Systemic-to-pulmonary Venous Shunt or Persistent Left Superior Vena Cava? A Rare Right-to-left Shunt Case-based Discussion.” J Cardiovascular Echogr. 2017 Jul-Sep;27(3)104-106 doi: 10.4103/jcecho.jcecho_42_16 DISCLOSURES: No relevant relationships by Jaskiran Khosa, source=Web Response no disclosure on file for Steve Lee

Lesion Type Analysis of Hemodialysis Patients Who Underwent Endovascular Management for Symptomatic Central Venous Disease.

PurposeCentral venous lesions (CVLs) can adversely affect hemodialysis access maturation and maintenance, which in turn worsen patient morbidity and access circuit patency. In this study, we assessed several clinical variables, patient characteristics, and clinical consequences of symptomatic central vein stenosis and obstruction in patients who underwent renal replacement therapy in the form of hemodialysis.Patients and MethodsThe medical records of all hemodialysis patients with clinically symptomatic CVLs who underwent digital subtraction angiography treatment at King Abdullah University Hospital between January 2017 and December 2019 were retrieved. Patient characteristics and the clinical and anatomical features of CVLs were analyzed retrospectively. Pearson’s chi-square tests of association were used to identify and assess relationships between patient characteristics and CVLs.ResultsThe study cohort comprised 66 patients with end-stage renal disease who developed symptomatic central vein stenosis. Of the 66 patients, 56.1% were men, and their mean age was approximately 52 years. Most (62.1%) of the patients were determined to have a history of central catheter insertion into the jugular vein. Hypertension was the most common comorbidity (78.8%, p<0.001), followed by type 2 diabetes mellitus (47.0 %, p<0.01). The incidence of stenosis was found to be significantly higher in the brachiocephalic vein than in other central veins (43.9%, p<0.001). A repeated central catheter insertion in a patient was predictive of central venous occlusion (p<0.05). Stenotic lesions were found to be associated with a significantly higher success rate than occlusive lesions (91.2%, p<0.01).ConclusionMultiple central venous catheters (CVCs) are found to be associated with occlusive CVLs and unfavorable recanalization outcomes. Multiple CVC should be avoided by creating a permanent vascular access in a timely fashion for patients with chronic kidney disease and by avoiding the ipsilateral insertion of CVC and AVF.

Challenges and novel therapies for vascular access in haemodialysis.

Advances in standards of care have extended the life expectancy of patients with kidney failure. However, options for chronic vascular access for haemodialysis - an essential part of kidney replacement therapy - have remained unchanged for decades. The high morbidity and mortality associated with current vascular access complications highlights an unmet clinical need for novel techniques in vascular access and is driving innovation in vascular access care. The development of devices, biological approaches and novel access techniques has led to new approaches to controlling fistula geometry and manipulating the underlying cellular and molecular pathways of the vascular endothelium, and influencing fistula maturation and formation through the use of external mechanical methods. Innovations in arteriovenous graft materials range from small modifications to the graft lumen to the creation of completely novel bioengineered grafts. Steps have even been taken to create new devices for the treatment of patients with central vein stenosis. However, these emerging therapies face difficult hurdles, and truly creative approaches to vascular access need resources that include well-designed clinical trials, frequent interaction with regulators, interventionalist education and sufficient funding. In addition, the heterogeneity of patients with kidney failure suggests it is unlikely that a 'one-size-fits-all' approach for effective vascular access will be feasible in the current environment.

Efficacy of stent-graft placement to salvage central vein stents with recalcitrant restenosis in patients with arteriovenous fistulas.

The purpose of this study was to determine the effectiveness and permanency of stent-graft placement to salvage stents with recalcitrant restenosis due to central vein stenosis (CVS). Between May 2014 and February 2016, VIABAHN stent-grafts were deployed in patients with functioning arteriovenous (AV) fistulas who underwent previous bare metal stent (BMS) placement and had recalcitrant stent restenosis that did not respond to percutaneous transluminal angioplasty (PTA). Surveillance was carried out at 3, 6, 12, 18, and 24months with diagnostic fistulography. Fourteen patients initially underwent 15 BMS placements. In the follow-up period (range, 118-976days), patients presented with symptomatic venous hypertension; subsequently, a total of 52 unsuccessful repeat PTAs for BMS restenosis were undertaken, and the median primary access survival of PTAs was 66±43days. For salvage, 14 stent-grafts were placed in segments with recalcitrant restenosis of a CVS stent. Within 1.25±0.72days after stent-graft placement, patients who initially presented with symptomatic venous hypertension reported complete resolution. The median primary access survival (mean, 1183±312days) was longer than PTAs alone (P<.01). No major or minor complications were associated with stent-graft deployment or any of the subsequent interventions in the study period. The primary patency rate at 6, 12, and 18months was 100%, and it was 85.7% at 24months. The secondary access patency rate was 92.9% at 24months. In conclusion, stent-graft placement to salvage CVS stents with recalcitrant restenosis in patients with AV fistulas is safe and effective if PTAs fails to maintain luminal patency.

Mid-term Outcomes of Patients with Central Venous Occlusive Disease Undergoing Surveillance Venography and Intervention

To evaluate the mid-term outcomes of regular surveillance venography with or without percutaneous transluminal angioplasty (PTA) in haemodialysis patients presenting with central venous occlusive disease. A single-centre retrospective analysis of haemodialysis patients who presented with central vein occlusion (CVO) and central vein stenosis (CVS) between January 2008 and December 2011 was performed. CVO and significant CVS were defined as 100% and >50% luminal narrowing, respectively. Upon successful angioplasty on first presentation, patients were followed up with regular surveillance venography within 3-6 months of the intervention and were re-treated when a significant stenosis or occlusion was demonstrated. Data on patient's demographics, comorbidities, presenting symptoms, type of upper limb dialysis access, lesion characteristics and complications were collected. Technical success, primary patency and primary assisted patency were analysed. Thirty-five patients with CVO and 77 patients with CVS were enrolled. The technical success of initial PTA was 77% and 73% for the CVO and CVS groups, respectively. The primary patency at 3 months was 65% and 55% for the CVO group and CVS group, respectively (P = 0.32). The primary assisted patency at 1 year was 88% and 99% for the CVO group and CVS group, respectively (P = 0.009). At 2 years, the primary assisted patency were 77% and 90%, respectively (P = 0.07). There was significant difference in the overall primary assisted patency (P = 0.048) between the CVO and CVS groups. CVOs are more difficult to treat than CVS. High primary assisted patency rates can be achieved with surveillance venography, albeit at the expense of increased number of interventions. Further cost effectiveness studies need to be performed to study the true benefit of our surveillance programme.

P1319AMBIGUOUS RESULTS OF CENTRAL VEIN STENOSIS ENDOVASCULAR TREATMENT IN HEMODIALYSIS PATIENTS

Abstract Background and Aims Balloon angioplasty (BA) without the use of stents has unsatisfactory results, which may cast doubt on its expediency. At the same time, BA is a very expensive treatment method. We conducted a comprehensive comparative analysis of the native arteriovenous fistula (AVF) patency rates in hemodialysis patients with central venous stenosis (CVS) after endovascular BA and «open» palliative surgery. Method A retrospective study included 80 patients with confirmed central vein stenosis: subclavian, brachiocephalic veins, vena cava inferior, or multiple lesions. The main group included 39 patients who underwent percutaneous balloon angioplasty. The control group included 41 patients who did not have balloon angioplasty for various reasons. In this patients we performed only «open» palliative interventions: thrombectomy, proximalization of arteriovenous anastomosis, AVF blood flow reduction. Results Functional primary patency (the time interval between the start of AVF using and the first intervention) did not differ: groups were comparable in time of stenosis manifestation (fig. 1A). Primary patency (the time interval between the first and second interventions) after BA was statistically significantly better than in the main group (fig. 1B), but difference was minimal: median survival in the study group of 8 months [95% CI 6; 10] vs. - 6 months [95% CI 4.9; 7.1]. There was the strong negative correlation between the primary patency and functional primary patency in the main group (r = –0.627 [95%CI –0.787; –0.388], p &amp;lt;0.0001) but not in the control group (r = 0.049 [95%CI –0.262; –0.351], p = 0.7599). Thus, the later manifestation of CVS related with lower effectiveness of BA. The functional secondary patency (total duration of AVF use) in the main group was significantly better: median survival was 47 months [95% CI 40.9; 53.1] vs. 34 months [95% CI 29.8; 38.2] as well as secondary patency (the time interval between the first intervention and the complete cessation of AVF use): median survival was 16 months [95% CI 12.5; 19.5] vs. 7 months [95% CI 4.9; 9.1] (fig. 1 C and D). The occlusion-free period from the moment of starting the AVF use (functional primary assisted patency – fig. 1E) was higher in the main group, but difference was minimal: median survival was 39 months [95% CI 36.5; 41.5] vs. 32 months [95% CI 27.5; 36.5], as well as occlusion-free period from the moment of the first surgical intervention (primary assisted patency – fig. 1F) median survival was 9 months [95% CI 7; 11], in the control group - 7 months [95% CI 5.6; 8.4]. The need for open interventions was lower in the main group: 0.374 [95% CI 0.24; 0.556] and 2.451 [95% CI 1.1963; 3.023] per 10 patient-months, incidence rate ratio (IRR)= 0.153 [95% CI 0.095; 0.237], р&amp;lt;0.0001; as well as overall need for interventions: 1.511 [95% CI 1.225; 1.843] and 2.451 [95% CI 1.963; 3.023] per 10 patient-months, IRR 0.617 [95% CI 0.461; 0.825] p=0.0011. The value of AVF volume blood flow had a strong negative correlation with the primary patency in both groups (r = –0.529, p =0.0027; r = –0.419, p =0.0101). Conclusion 1. Central vein stenosis is inevitably leads to loss of vascular access on the ipsilateral side. 2. Balloon angioplasty allows to extend the period of AVF use but it is not a radical treatment method of CVS. 3. The results of balloon angioplasty are significantly affected by the length of the period from the start of AVF use to the CVS manifestation. 4. Multiple repeated BA are apparently justified in patients for whom the possibility of creating a new vascular access is doubtful. 4. The AVF volume blood flow is an important factor determining the severity of CVS clinical manifestations and the need for repeated surgical interventions.

P1329STENTING VERSUS ISOLATED BALLOON ANGIOPLASTY FOR CENTRAL VEIN STENOSIS IN HEMODIALYSIS PATIENTS

Abstract Background and Aims comparative analysis of the results of isolated balloon angioplasty (BA) and BA with stenting of central veins stenosis in patients on hemodialysis. Method A retrospective study included 62 patients with confirmed stenosis of the central veins: subclavian, brachiocephalic veins, vena cava inferior, or multiple lesions. In 39 patients, stents are not used; isolated balloon angioplasty (BA) was performed. In 23 patients we used bare metal stents. Results Functional primary patency (the time interval between the start of AVF using and the first endovascular intervention) did not differ in the groups – fig. 1A; HR 1.142 [95% CI 0.6875; 1.897], p = 0.5994. The use of stents leads to increase primary patency (the time interval between the first and second endovascular interventions) – fig. 1B; HR 2.064 [95% CI 1.252; 3.404], p = 0.0017. The use of stents allows to increase the functional secondary patency (total duration of use of the AVF) – fig 1C; HR 2.099 [95% CI 1.272; 3.463], p = 0.0016. Secondary patency (the time interval between the first endovascular intervention and the complete cessation of the use of AVF) was higher after BA with stenting: HR 2.03 [95% CI 1.232; 3.347], p = 0.0021; fig 1D. The use of stents allows to increase functional primary assisted patency (non-occlusive period from the start of AVF use) – fig. 1E and primary assisted patency (non-occlusive period from the first surgical intervention) – fig 1F: HR 1.936 [95% CI 1.175; 3.188], p= 0.0053 and HR 2.0 [95% CI 1.213; 3.295], p = 0.0042. The need for open reconstructive interventions after the first BA or BA with stenting was the same 0.374 [95% CI 0.24; 0.556] and 0.45 [95% CI 0.291; 0.664] per 10 patient-months, incidence rate ratio (IRR)= 0.831 [95% CI 0.471; 1.464] р=0.521. The need for endovascular interventions did not differ between isolated BA and BA with stenting 1.137 [95% CI 0.8913; 1.43] and 0.827 [95% CI 0.606; 1.104] per 10 patient-months, IRR=1.374 [95% CI 0.952; 1.999] p=0.09. Total need for surgical interventions (open + endovascular) also did not differ: 1.511 [95% CI 1.225; 1.843] and 1.277 [95% CI 0.997; 1.611] per 10 patient-months, IRR 1.183 [95% CI 0.872; 1.612] p=0.2822. We found a strong negative correlation between functional primary patency and primary patency (r = -0.627; p &amp;lt;0.0001) – fig. 2, as well as a between functional primary patency and secondary patency in patients after isolated BA (= -0.53; p = 0.0005, respectively), but not after stenting (r = -0.351; p = 0.101 and r = -0.304; p = 0.159, respectively). In a case of isolated BA, the success of the first intervention largely determines the secondary patency, which is expressed in a strong, statistically significant positive correlation of primary patency and secondary patency. In a case of BA with stenting, the correlation between these estimates is also statistically significant, but significantly lower. Conclusion 1. The results of balloon angioplasty without stenting are significantly influenced by the duration of the period between the start of AVF use and the manifestation of central vein stenosis. 2. The use of stents can slightly improve the results of endovascular interventions in central vein stenosis, regardless the its time of development. 3. The use of stents leads to a moderate increase in the median patency of AVF and a significant increase in the proportion of patients with functional AVF in the late postoperative period. 4. The use of stents does not reduce the need for surgical interventions

P1362AN EXPERIENCE WITH PERCUTANEOUS TRANSLUMINAL ANGIOPLASTY IN ARTERIO-VENOUS FISTULA DYSFUNCTION SECONDARY TO VASCULAR STENOSIS

Abstract Background and Aims Arterio-venous fistula (AVF) is the life line of a hemodialysis patient. Dialysis Outcomes and Practice Study (DOPPS) showed that one year patency for AVF in the USA is 68% and 83% in Europe. The maintenance of the vascular pathways are vital. Vascular stenosis in native AVF at the anastomotic sit, venous cannulation zone, outflow vein or the central vein can lead to loss of AVF. Stenosis necessitate vascular intervention or creation of a “de novo” AVF. The number of possible vascular access sites are limited. Aim : To evaluate the outcome of percutaneous transluminal angioplasty (PTA) in arterio-venous fistula due to vascular stenosis. Method This is a retrospective study of two years (02.05.17 to 02.05.19). Records of patients admitted to our hospital were obtained from hospital archives and images from the hospital radiology archive system. Demographic characteristics, duration of dialysis, stenosis or occlusion level, patency rates of AVF were evaluated. All procedures were performed by interventional radiologists in a hybrid cath lab. Antegrade, retrograde, or both antegrade and retrograde punctures were used, depending on the site of the stenosis as deemed on preoperative ultrasound. A complete angiogram from the proximal arteriovenous anastomosis to the central venous outflow was performed in all cases. A successful percutaneous balloon angioplasty was defined when there was no more than 30% residual stenosis (KDOQI). Primary patency rates were assessed at six months and one year. Results Total number of patients studied were 16. The average age was 66.6 years. All were hypertensive and diabetics comprised 75% of study group. Coronary artery disease was established in 81.25%, and two patients were known to have chronic liver disease. Most common type of AVF was the left brachio-cephalic (62.5%), followed by radio-cephalic (37.5%). Average dialysis vintage of AVF at the time of procedure was one year. Previously failed AVF was present in two patients. There were 18 vascular stenosis in 16 patients. The most common site of stenosis was the venous cannulation zone (62.5%), followed by anastomotic site stenosis (31.5%) and central vein stenosis (18.75%). Successful PTA was done in 12 patients. There were no complications; hemodialysis was resumed within 24 hours after the procedure. The primary patency rate at three months was 100%, six months was 75% and at one year it was 37.5%. Four patients were lost to follow up. Mean follow up was 9.41 ±6.79 months. None underwent a repeat PTA. Conclusion Percutaneous transluminal angioplasty is effective for salvaging arterio-venous fistula in majority of hemodialysis patients.

Ambiguous results of balloon angioplasty for central vein stenosis in hemodialysis patients with native arteriovenous fistula

Objective : to conduct comprehensive comparative analysis of the patency rate of native arteriovenous fistula (AVF) for central vein stenosis (CVS) after endovascular balloon angioplasty and palliative surgery. Materials and methods . The retrospective study included 80 patients with confirmed central vein stenosis: subclavian, brachiocephalic veins, inferior vena cava, or multiple lesions. The experimental group included 39 patients who underwent percutaneous balloon angioplasty. The control group included 41 patients who, for various reasons, did not do balloon angioplasty, but underwent palliative interventions: thrombectomy, proximalization of arteriovenous anastomosis, AVF blood flow-reducing surgical procedures. Results . Primary patency (time interval between the first intervention for CVS and the second intervention) in the experimental group was 61.5% [95% CI 44.5; 74.7] and 15.4% [95% CI 6.2; 28.3] at 6 and 12 months, respectively. In the control group, it was 39% [95% CI 24.3; 53.4] and 0% respectively. Hazard ratio (HR) 0.5337 [95% CI 0.3381; 0.8427], log-rank test p = 0.0011. No differences in functional primary patency (time interval between the start of using AVF and the first intervention for CVS) were found: 89.7% [95% CI 74.9; 96] and 30.8% [95% CI 17.3; 45.4] at 1 year and 3 years, respectively, in the experimental group, and 80.5% [95% CI 64.8; 89.7] and 24.4% [95% CI 12.7; 38.2] in the control group. There were no differences between the groups HR 0.7695 [95% CI 0.4952; 1.196], log-rank p = 0.2259. In the experimental group, strong negative correlation between primary patency and functional primary patency was detected: r = –0.627 [95% CI –0.787; –0.388], p < 0.0001. In the control group, no such correlation was found: r = 0.049 [95% CI –0.262; –0.351], p = 0.7599. Thus, the later CVS developed, the less effective balloon angioplasty was. Balloon angioplasty significantly increased duration of AVF use after first intervention for CVS (secondary patency): 84.6% [95% CI 68.9; 92.8], 66.7% [95% CI 49.6; 79.1] and 17.9% [95% CI 7.9; 31.3] at 6, 12 and 24 months, respectively in the experimental group. In the control group, it was 56.1% [95% CI 39.7; 69.6], 19.5% [95% CI 9.2; 32.7] and 0%. HR 0.4009 [95% CI 0.2481; 0.6477], log-rank p < 0.0001. Functional secondary patency (total duration of AVF use) was: 100%, 74.4% [95% CI 57.6; 85.3] and 12.8% [95% CI 4.7; 25.2] at 1, 3 and 5 years in the experimental group, and 95.1% [95% CI 81.9; 98.8], 36.6% [95% CI 22.3; 51] and 4.9% [95% CI 0.9; 14.5] in the control group. HR 0.5661 [95% CI 0.3598; 0.8906], log-rank p = 0.0067. Conclusions . 1. Central vein stenosis inevitably cuts vascular access from the ipsilateral side. 2. Balloon angioplasty allows to slightly prolong AVF use but it cannot radically change the long-term results of CVS treatment. 3. The outcome of balloon angioplasty greatly depends on the length of the period from the time the use of AVF started to the time CVS developed. 4. Multiple repeated balloon angioplasties are apparently justified in patients for whom creating a new vascular access might not be possible. 4. AVF volumetric blood flow velocity is an important factor determining the severity of CVS clinical manifestations and whether repeated surgical interventions are needed.

Drug-coated balloon versus conventional balloon angioplasty of hemodialysis arteriovenous fistula or graft: A systematic review and meta-analysis of randomized controlled trials.

BackgroundRestenosis remains a significant problem in endovascular therapy for hemodialysis vascular access. Drug-coated balloon (DCB) angioplasty decreases restenosis in peripheral and coronary artery diseases. The aim of this systematic review and meta-analysis is to assess the patency outcomes following DCB angioplasty, as compared to conventional balloon (CB) angioplasty for the stenosis of hemodialysis vascular access.MethodsA comprehensive search in the MEDLINE, EMBASE, and CENTRAL databases was conducted in order to identify eligible randomized controlled trials evaluating DCB angioplasty for hemodialysis vascular access dysfunction. The primary endpoint was the 6-month target lesion primary patency and the secondary endpoints were 12-month target lesion primary patency and procedure-related complications. Risk ratios (RR) were pooled and relevant subgroups were analyzed separately.ResultsEleven randomized controlled trials comprised of 487 patients treated with DCB angioplasty and 489 patients treated with CB angioplasty were included. There were no significant differences in the target lesion primary patency at 6 months [RR, 0.75; 95% confidence interval (CI), 0.56, 1.01; p = 0.06] and at 12 months (RR 0.89; 95% CI, 0.79, 1.00; p = 0.06). The absence of benefit for the DCB group remained, even in the arteriovenous fistula subgroup or the subgroup of studies excluding central vein stenosis. The risk of procedure-related complication did not differ between the two groups (RR 1.00; 95% CI 0.98, 1.02; p = 0.95).ConclusionDCB angioplasty did not demonstrate significant patency benefit for the treatment of hemodialysis vascular access dysfunction. Wide variations in patency outcomes across studies were noted. Further studies focusing on specific types of access or lesions are warranted to clarify the value of DCB for hemodialysis vascular access. (PROSPERO Number CRD42019119938)

Novel Approach to Treatment of Chronic Iliocaval Occlusion Utilizing Covered Stents

Chronic iliocaval obstruction is a challenging clinical entity to treat. Endovenous iliocaval stenting is becoming the treatment of choice for central vein stenosis and occlusion. However, outcomes in thrombotic disease have not been as robust as nonthrombotic disease. In this article, we describe our experience utilizing covered stents as a novel tool for chronic total occlusions of the iliocaval veins. We performed a retrospective review of a prospectively maintained database of all patients undergoing endovenous stenting with a covered stent for chronic occlusive iliocaval disease over a 3-year period at our institution. Patients were followed clinically and with venous duplexes to assess the feasibility, safety, and outcomes of iliocaval endovenous stenting with covered stents. A total of 10 patients (8 men and 2 women) underwent iliocaval stenting with covered stents from July 2015 to May 2018. A total of 20 self-expanding covered stents (SECS) and 13 balloon expandable covered stents (BECS) were deployed in the central veins of the 10 patients. Six SECS and 5 BECS were deployed in the inferior vena cava, 10 SECS and 6 BECS were deployed in the common iliac veins (CIVs) (5 patients had bilateral CIV BECS and 2 patients had bilateral CIV SECS), and 4 SECS and 2 BECS were deployed in the external iliac veins (2 patients had bilateral SECS placed). Median follow-up time was 12.1 (range 0.5-35.0) months. There were no perioperative or postoperative complications. Nine (90%) patients maintained primary stent patency during our follow-up time. One patient (10%) had rethrombosis of his stent due to undertreated common femoral vein disease in the setting of a new myeloproliferative neoplasm and an inappropriate cessation of therapeutic anticoagulation. All patients who were symptomatic preoperatively had improvement in their pain, venous ulceration, and venous claudication. Eight of nine (89%) patients had improvement in their lower extremity edema. Covered endovenous stenting of chronically occluded central veins is a safe and promising procedure. Their use may improve the short- and long-term outcomes in this challenging patient population. Further studies are required to evaluate the long-term efficacy and cost of their use.