Central vein stenosis

Recanalization of a long segment occluded superior vena cava by puncturing the remnant calcified fibrin sheath of the internal jugular vein: A case report

A fibrin sheath with central venous occlusion is a common complication after central venous catheterization, and these patients often experience catheter dysfunction. A calcified fibrin sheath can cause a catheter to be stuck, and typically necessitates catheter removal or replacement. From another point of view, a calcified fibrin sheath can be seen in ultrasound and computed tomography, and the original fibrin sheath channel between the internal jugular vein and the atrium is unusually strong. When central vein occlusion occurs, the remnant calcified fibrin sheath of the internal jugular vein can be punctured under ultrasound guidance, allowing the guidewire to enter the atrium directly through the fibrin sheath. Here, we report a case in which we achieved easy recanalization of a long segment occluded superior vena cava by puncturing the remnant calcified fibrin sheath of the internal jugular vein.

HeRO graft-The results of the cologne single center study

OBJECTIVE

The HeRO graft is a technique for vascular access in patients with limited treatment options; however, the published results with the HeRO graft are diverging. We therefore conducted a single-center study.

METHODS

Patient records between July 2014 and February 2020 from Vascular Access Unit of the Department of Vascular and Endovascular Surgery of University Clinic of Cologne (Germany) were reviewed. Retrospective data was analysed from patients with a HeRo graft (n = 18).

RESULTS

Eighteen patients were enrolled in the study. The mean age of the patients was 62.8 ± 17.24 years. During the follow-up period, no patients died from complications related to the HeRO graft. Each patient had a mean of 1.94 concomitant diseases. The primary patency rates of the HeRO graft at 3, 6, 12, 18, and 24 months were 61.1%, 50%, 16.7%, 11.1%, and 5.6%, respectively. The secondary patency rates at the same time intervals were 77.8%, 72.8%, 55.6% 55.6%, and 55.6%, respectively. There were 44 re-operations per year, or 2.4 operations per patient. The main cause of acute complications was acute graft occlusions after HERO graft implantation. An infection after the graft implantation occurred in five (27.7%) patients, leading to graft explanation in 2 cases.

CONCLUSION

The use of the HERO graft is a valuable alternative method for providing a durable dialysis access in patients with limited access options. The secondary patency and survival are good with a low infection rate.

Clinical outcomes and predictive factors of stent grafts treatment for symptomatic central venous obstruction in end stage kidney disease patients with arteriovenous access

To assess the efficacy of stent grafts (SGs) in managing central venous obstruction disease (CVOD) in hemodialysis (HD) patients with arteriovenous (AV) access, and to identify predictive factors influencing the SG treatment outcomes. HD subjects with CVOD who underwent SGs placement at our center between August 2018 and June 2022 were enrolled. Survival curve analysis using the Kaplan-Meier method and log-rank test was performed. Cox proportional hazards regression analysis was employed to identify predictive factors associated with outcomes. A total of 59 SG implantation procedures for CVOD were analyzed, comprising 30 cases of stenosis and 29 cases of occlusion. The access circuit primary patency (ACPP) at 6, 12, and 24 months post-SG placement were 80.9%, 53.8%, and 31.4%, respectively, while, the target lesion primary patency (TLPP) were 91.3%, 67.6%, and 44.5%, respectively. Subgroup analysis revealed higher TLPP in the stenosis group compared to the occlusion group, although the difference was not statistically significant (P = 0.165). The TLPP was significantly improved by SG placement in those who had antecedent balloon dilations (P < 0.001). Cox proportional hazards regression identified target lesion length ≥ 30 mm and procedure defects as independent predictors of lower TLPP after SG treatment for CVOD in HD patients. SG placement demonstrates safety and efficacy in managing CVOD among HD patients, leading to improved TLPP of endovascular therapy (EVT) for CVOD. Notably, long target lesions (≥ 30 mm) and procedure defects emerged as predictive factors influencing TLPP.

Risk factors for in-stent restenosis in maintenance hemodialysis patients with central venous occlusive disease and biomechanical assessment of stents

OBJECTIVES

To investigate the risk factors and biomechanical mechanisms of in-stent restenosis (ISR) in central venous occlusive disease (CVOD).

PATIENTS AND METHODS

This retrospective study consecutively included 77 maintenance hemodialysis (MHD) patients with CVOD who received the first percutaneous transluminal angioplasty with stenting (PTS) due to symptomatic CVOD in a tertiary hospital. The mean age was 59.7 ± 14.0 years, and 51.9% of patients were male. The clinical characteristics, occurrence of ISR and patency rates were recorded. Finite element method was applied to assess the biomechanical properties of stents.

RESULTS

Among 77 patients with a mean CVS score of 8.0 ± 2.8, 20.8%, 62.3%, and 16.9% of patients had the main vein of CVOD in the subclavian vein, brachiocephalic vein, and superior vena cava, respectively. A total of 72 (93.5%) patients received successful PTS treatment, for which the stents implanted were mainly Fluency covered stent (48.6%) and SMART bare stent (31.9%). During 15 (10-24)-months of follow-up, ISR occurred in 36.1% of the 72 patients. The primary and assisted primary patency rates at 6, 12, and 18 months were 78%, 56%, 42% and 95%, 90%, 87%, respectively. A prolonged dialysis vintage was an independent risk factor for ISR, yet the stent type or the main vein location was not correlated with ISR. Among three laser-engraving stents, the SMART stent was the best in terms of flexibility, stress, and strain on stents but worst in stress or strain on vessels. The Luminexx stent was the best in radial force and worst in stress or strain on stents. The Vici stent was the best in stress and strain on vessels and worst in radial force and flexibility.

CONCLUSIONS

An unsatisfactory comprehensive biomechanical performance from configurations rooted in existing stents may account for the high incidence of ISR in CVOD.

Outcomes of stent grafts for treatment of central venous disease in hemodialysis patients

BACKGROUND

To evaluate the effectiveness of stent graft (SG) for the treatment of central venous disease (CVD) in hemodialysis patients.

METHODS

Between January 2014 and April 2022, 122 patients on hemodialysis with symptomatic CVD were treated with percutaneous transluminal angioplasty (PTA) and bare-metal stent (BMS) or SG placement. The mean follow-up was 14.5 months (IQR: 8.0, 24.2). Patency rates of the target sites were calculated using Kaplan-Meier and log-rank studies. Multivariate Cox proportional hazard models were used to evaluate the association between various characteristics and target site primary patency.

RESULTS

Technical success rate was 100%. At 3, 6, 12, and 24 months, the target sites primary patency rates were 86.4%, 74.2%, 45.1%, and 30.4% for PTA; 94.7%, 78.6%, 60.8%, and 45.6% for BMS; and 94.0%, 92.0%, 82.4%, and 66.8% for SG, respectively, and the assisted primary patency rates were 86.5%, 80.4%, 63.8%, and 46.0% for PTA; 94.7%, 89.5%, 77.5%, and 71.1% for BMS; 100%, 100%, 97.8%, and 83.4% for SG, respectively. The Kaplan-Meier analysis indicated that SGs achieved better primary and assisted primary patency than PTA or BMS (p<0.05). SG use and concomitant stenosis were the independent predictors of target site primary patency dysfunction in the multivariate analysis.

CONCLUSIONS

This study confirmed the better long-term patency of SG in comparison with PTA and BMS for the treatment of CVD in hemodialysis patients.

Re-hospital admission, morbidity and mortality rate in patients undergoing tunnelled catheter implantation for haemodialysis

OBJECTIVE

Despite the effort to increase the proportion of patients starting dialysis on native accesses, many of them are still dialyzed on tunnelled catheter. Catheter-related complications are often serious and responsible for re-hospital admission, high morbidity and mortality. Several multicenter trials have reported results in the use of tunnelled dialysis catheter (TDC). However, few single-center studies have been published to verify the outcome from real-world experience. This study presents our center's experience in managing such patients in the context of relevant literature.

METHODS

Demographics and operative data were retrospectively collected from medical charts. A prospective follow-up was performed to investigate complications, number of re-hospitalizations and mortality. Kaplan-Meier estimate was used to evaluate catheter primary patency and patients' overall survival.

RESULTS

Among a total 298 haemodialysis accesses interventions, 105 patients (56 men, 53.3% and 49 women, 46.7%) with a median age of 65 years (range 32-88 years) were included in the study. All insertions were successful with an optimal blood flow achieved during the first session of dialysis in all cases. A catheter-related complication was detected in 33.3% (n=35) patients (48.6% infections; 28.6% TDC dysfunction; 14.3% local complications; 5.7% accidental catheter retractions; 2.8% catheter migrations). At a median follow-up of 10.5±8.5 months, a total of 85 patients (80.9%) was re-hospitalized, in 28 cases (26.7%) for a catheter-related cause. The median catheter patency rate was 122 days. At the last follow-up, 39 patients (37.1%) were still dialyzed on catheter, 30(28.6%) were dialyzed on an arteriovenous fistula and 7(6.7%) received a kidney transplantation. Two patients (2%) were transferred to peritoneal dialysis and two patients (2%) recover from renal insufficiency. Mortality rate was 23.8% (25 patients). Causes of death were myocardial infarction (n=13, 52%), sepsis (n=9, 36%); one patient (4%) died from pneumonia, one (4%) from uremic encephalopathy and one (4%) from massive hematemesis.

CONCLUSION

TDCs may represent the only possible access in some patients, however they are burned with a high rate of complications, re-hospital admission and mortality. Results from this institutional experience are in line with previously published literature data in terms of morbidity and mortality. The present results reiterate once more that TDC must be regarded as a temporary solution while permanent access creation should be prioritized. Strict surveillance should be held in patients having TDC for the early identification of complications allowing the prompt treatment and modifying the catheter insertion site whenever needed.

Hemorrhagic pericardial tamponade in a hemodialysis patient with catheter-related superior vena cava syndrome: a case report

BACKGROUND

Iatrogenic complications of endovascular treatment for central venous stenosis have not yet been reported. Here we present a case of a patient on maintenance hemodialysis who developed catheter-related superior vena cava syndrome and subsequently suffered from hemorrhagic pericardial tamponade after undergoing percutaneous transluminal angioplasty and stenting.

CASE PRESENTATION

A 72-year-old male patient presented with uremia, and had been receiving maintenance hemodialysis for the past five years. The patient initially presented with dysfunction of the dialysis catheter (a cuffed tunneled double-lumen catheter in the right internal jugular vein). Imaging examination revealed a segmental occlusion of the superior vena cava stretching from the distal end of the dialysis catheter up to right atrium entrance, apparent compensatory dilatation of the azygos vein, and abundant subcutaneous collaterals. The patient underwent percutaneous transluminal balloon dilatation and stenting (covered stent) of the superior vena cava in the Cath Lab. During the procedure, with forceful advancement of the guidewire, it was observed to progress for a distance before a "smoke" appeared, and an outward spillage of contrast agent was visible, which suggested a possible vessel puncture leading into the mediastinum. Unfortunately, postoperative hemorrhagic pericardial tamponade occurred and the patient developed cardiogenic shock. He experienced symptoms included chest tightness and breath shortness with a recorded blood pressure of 84/60mmHg. After draining 600 ml of bloody fluid through pericardiocentesis, the patient's symptoms alleviated and his condition improved.

CONCLUSIONS

The case emphasizes the need for increased attention to iatrogenic endovascular injuries during catheter placement and endovascular treatment, such as causing pericardial hemorrhage leading to cardiac tamponade.

Fatal superior vena cava rupture complicating dialysis catheter exchange

Central vein stenosis (CVS) is a common and challenging complication in hemodialysis patients with chronic central venous catheters (CVCs). CVS often remains asymptomatic and is discovered incidentally during follow-up imaging. CVS symptoms include arm swelling, venous hypertension, impaired dialysis flow rates, and development of collateral veins. However, these symptoms can be nonspecific and overlap with other conditions, making the diagnosis challenging. Timely recognition and appropriate intervention are crucial to prevent complications and optimize patient outcomes. Diagnostic tools commonly used include duplex ultrasonography and venography to assess the degree and location of stenosis. Management strategies for CVS encompass a multidisciplinary approach involving nephrologists, interventional radiologists, and vascular surgeons. Initial conservative measures may include anticoagulation therapy, along with pharmacological interventions such as antiplatelet agents and thrombolytics. The endovascular approach is the first line for managing CVS by using balloon angioplasty either alone or in combination with stent placement, but CVS typically recurs frequently, requiring repeated interventions with an increased risk of complications. Additionally, alternative vascular access options such as arteriovenous fistulas or grafts may be considered. In this report, we describe a case of a 25-year-old woman who presented with an extensive history of multiple dialysis access failure for left internal jugular vein central venous tunneled catheter exchange. The procedure was complicated by a fatal superior vena cava rupture likely related to the dislodgment of the guidewire causing perforation into the pericardium space with subsequent cardiopulmonary collapse. The post-mortem autopsy showed severe organized stenosis of SVC and transmural defect above the SVC/atrial junction.

Macro- and microscopic changes in veins with short-term central venous catheters: an observational autopsy study

BACKGROUND

Centrally inserted central catheters (CICCs) are indispensable in modern healthcare, but unfortunately, come with complications. Catheter-related thrombosis is a well-known complication reported to occur in 5-30% of patients with CICC. There is a paucity of studies that report the incidence of catheter-related thrombosis after the introduction of real-time ultrasound insertion guidance as clinical practice. This study aimed to demonstrate any pathological macro- or microscopic changes in the vein wall associated with CICCs.

METHODS

The study was approved by the Swedish Ethical Review Authority and was conducted at a large university hospital. The study included 12 patients with a short-term CICC who were subject to autopsies. Vessels with inserted catheters were macroscopically and microscopically examined.

RESULTS

In total, seven female and five male patients with a median age of 70 (interquartile range 63-76) were included. With one exception, all patients received routine thromboprophylaxis throughout the period with CICC. Most inserted CICCs were 9.5 French (54%) and were inserted in the internal jugular vein (92%). The median time with CICC was seven days (interquartile range 1.8-20). At autopsy, thrombi were observed in all cases (100%), macroscopically and microscopically, attached to the distal portion of the CICC and/or the adjacent vessel wall. Inflammatory changes in the vessel walls were seen in all cases, and varying degrees of fibrosis were demonstrated in eight cases (67%).

CONCLUSIONS

This autopsy study demonstrated that catheter-related thrombus formation with adjacent inflammatory and fibrotic vessel wall thickening was very common, despite a limited period of catheter use. The consequences of these findings are important, as thrombi may cause pulmonary embolism and possibly lead to catheter-related infections, and since inflammatory and fibrotic vessel wall thickening may evolve into chronic venous stenosis. Furthermore, the findings are a cause of concern, as CICCs are indispensable in modern healthcare and complications may be masked by the general disease that was the indication for CICC insertion.

Efficacy and Safety of Sharp Recanalization with the Stiff End of a Microguidewire for Treatment of Refractory Central Venous Occlusions in Hemodialysis Patients

BACKGROUND

Sharp recanalization is a viable procedure for some refractory central venous occlusions that cannot be recanalized with the conventional technique. The sharp recanalization procedures reported in previous studies are often rely on costly devices and with a certain proportion of complications. This study aimed to present an inexpensive and risk-controllable coaxial centrifugally sharp recanalization technique that was independent of any additional costly devices.

METHODS

This retrospective study enrolled 8 patients who had received sharp recanalization of central venous occlusions, between August 2017 and May 2021. The sharp recanalization technique was performed centrifugally with the stiff end of a microguidewire after the lesions failed to be passed through with the conventional technique. Clinical data of patients on their lesions, technical success rate, procedure-related complications, and patency rates were collected and analyzed to assess the efficacy and safety of the technique.

RESULTS

Technical success was achieved in all patients, with no complications were observed. All symptoms were ameliorated within 48h postsurgery. The median follow-up period was 22 months. All patients maintained patency or assisted patency at 12 month follow-up.

CONCLUSIONS

Sharp recanalization performed centrifugally with the stiff end of the microguidewire could be a cost-effective and safe alternative procedure for the treatment of refractory central venous occlusion that cannot be recanalized with conventional technique.

The clinical journey and healthcare resources required for dialysis access of end-stage kidney disease patients during their first year of hemodialysis

BACKGROUND

Creation and maintenance of dialysis vascular access (VA) is a major component of healthcare resource utilization and cost for patients newly started on hemodialysis (HD). Different VA format arises due to patient acceptance of anticipatory care versus late preparation, and clinical characteristics. This study reviews the clinical journey and resource utilization required for different VA formats in the first year of HD.

METHOD

Data of patients newly commenced on HD between July 2015 and June 2016 were reviewed. Patients were grouped by their VA format: (A) pre-emptive surgically created VA (SCVA), (B) tunneled central venous catheter (CVC) followed by SCVA creation, (C) long-term tunneled CVC only. Clinical events, number of investigations and procedures, hospital admissions, and incurred costs of the three groups were compared.

RESULTS

In the multivariable analysis, the cost incurred by the group A patients had no significant difference to that incurred in the group B patients (p = 0.08), while the cost of group C is significantly lower (p < 0.001). Both the 62.7% of group A with successful SCVA who avoided tunneled CVC usage, and those with a functionally matured SCVA in group B (66.1%), used fewer healthcare resources and incurred less cost for their access compared to those did not (p = 0.01, p = 0.02, respectively) during the first year of HD.

CONCLUSION

With comparable cost, a pre-emptive approach enables avoidance of tunneled CVC. Tunneled CVC only access format incurred lower cost and is suitable for carefully selected patients. Successful maturation of SCVA greatly affects patients' clinical journey and healthcare cost.

Diagnostic Value of Contrast-Enhanced Ultrasonography for Catheter-Related Right Brachiocephalic Vein and Superior Vena Cava Lesions in Patients Undergoing Hemodialysis-A Pilot Study

OBJECTIVES

To evaluate the diagnostic efficacy of contrast-enhanced ultrasonography (CEUS) for detecting catheter-related right brachiocephalic vein (RBV) and superior vena cava (SVC) obstructions in patients undergoing hemodialysis (HD).

METHODS

From June 1, 2021 to December 31, 2022, we enrolled 80 patients undergoing HD who had used or were using a central venous catheter as vascular access. We evaluated the diagnostic efficacy of conventional ultrasonography and CEUS for identifying RBV and SVC obstructions and compared them with that of digital subtraction angiography (DSA). In the stratified analysis, the SVC was divided into the upper and lower segments. In total, we analyzed 240 central venous segments, including the RBV.

RESULTS

Among the RBV and SVC visualized by DSA, conventional ultrasonography and CEUS could visualize 67.92 and 100% of the vein segments, respectively; however, the lengths and diameters of the RBV and SVC were smaller than those recorded with DSA (P < .001). The diagnostic efficacy of CEUS for detecting catheter-related central venous obstruction was better than that of conventional ultrasonography, with a higher sensitivity (83.95 vs 41.98%), specificity (89.94 vs 53.46%), accuracy (87.92 vs 49.58%), and F1 score (82.42 vs 49.64%). CEUS showed good agreement (κ = 0.732) with DSA. In the stratified analyses, CEUS also showed higher sensitivity (83.93, 83.33, and 84.62%, respectively) and better agreement with DSA (κ = 0.635, 0.655, and 0.673, respectively) than conventional ultrasonography for detecting the RBV and the upper and lower segments of the SVC.

CONCLUSIONS

CEUS had high sensitivity and specificity in diagnosing catheter-related RBV and SVC obstructions.

Central vein stenosis in hemodialysis vascular access: clinical manifestations and contemporary management strategies

Central venous stenosis is a significant and frequently encountered problem in managing hemodialysis (HD) patients. Venous hypertension, often accompanied by severe symptoms, undermines the integrity of the hemodialysis access circuit. In central venous stenosis, dialysis through an arteriovenous fistula is usually inefficient, with high recirculation rates and prolonged bleeding after dialysis. Central vein stenosis is a known complication of indwelling intravascular and cardiac devices, such as peripherally inserted central catheters, long-term cuffed hemodialysis catheters, and pacemaker wires. Hence, preventing this challenging condition requires minimization of central venous catheter use. Endovascular interventions are the primary approach for treating central vein stenosis. Percutaneous angioplasty and stent placement may reestablish vascular function in cases of elastic and recurrent lesions. Currently, there is no consensus on the optimal treatment, as existing management approaches have a wide range of patency rates.

ACR Appropriateness Criteria® Dialysis Fistula Malfunction

The creation and maintenance of a dialysis access is vital for the reduction of morbidity, mortality, and cost of treatment for end stage renal disease patients. One's longevity on dialysis is directly dependent upon the quality of dialysis. This quality hinges on the integrity and reliability of the access to the patient's vascular system. All methods of dialysis access will eventually result in dialysis dysfunction and failure. Arteriovenous access dysfunction includes 3 distinct classes of events, namely thrombotic flow-related complications or dysfunction, nonthrombotic flow-related complications or dysfunction, and infectious complications. The restoration of any form of arteriovenous access dysfunction may be supported by diagnostic imaging, clinical consultation, percutaneous interventional procedures, surgical management, or a combination of these methods. This document provides a rigorous evaluation of how variants of each form of dysfunction may be appraised and approached systematically. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Guidelines on vascular access for hemodialysis from the Brazilian Society of Angiology and Vascular Surgery

Chronic kidney disease is a worldwide public health problem, and end-stage renal disease requires dialysis. Most patients requiring renal replacement therapy have to undergo hemodialysis. Therefore, vascular access is extremely important for the dialysis population, directly affecting the quality of life and the morbidity and mortality of this patient population. Since making, managing and salvaging of vascular accesses falls within the purview of the vascular surgeon, developing guideline to help specialists better manage vascular accesses for hemodialysis if of great importance. Thus, the objective of this guideline is to present a set of recommendations to guide decisions involved in the referral, evaluation, choice, surveillance and management of complications of vascular accesses for hemodialysis.

Catheter-related superior vena cava obstruction: A rare cause of chylothorax in maintenance hemodialysis patients

With the extensive use of dialysis catheters in patients undergoing hemodialysis, superior vena cava (SVC) syndrome has gradually attracted attention in recent years. Chylothorax caused by SVC syndrome is rarely reported. In this paper, we report a case of chylothorax secondary to superior vena cava obstruction (SVCO) in a maintenance hemodialysis patient after multiple dialysis catheter placements. Relieving the SVCO through intravascular intervention could effectively treat chylothorax. In the past fourteen months, no recurrence of symptoms has been observed.

A Comparative Study of Continuous Versus Interrupted Suturing Technique in Creating a Vascular Access for Hemodialysis: An Institutional-Based Experience

Background Arteriovenous fistulas (AVFs) are considered the first and best access for patients with end-stage renal disease who need permanent vascular access for hemodialysis over arteriovenous grafts and central venous catheters for reasons that have been well-established. Poor early patency rates pose the biggest challenge in creating vascular access as they cause increased morbidity and economic/psychological concerns among patients. To minimize such effects, it is critical to use a patient-centered approach and carefully choose patients for AVF access creation. This study aimed to compare the primary patency of distal vascular access provided by continuous suturing versus that provided by interrupted suturing. Methodology This prospective study was conducted in the urology department of a superspecialty, tertiary care center from November 2021 to November 2022. Patency was assessed immediately after surgery (on the table), one month later, and six months later by palpating thrill and auscultating bruit. A total of 50 patients between the ages of 18 and 70 years who met the inclusion criteria were randomly assigned to two groups of 25 each. Results The baseline characteristics of both groups were comparable. At six months (p = 0.09), the continuous suturing group was observed to be somewhat better than the interrupted suturing group, with no significant difference in immediate and one-month patency rates. When compared to the continuous suturing group, the primary patency failure rate was significantly higher in the interrupted suturing group. Conclusions Thus, under appropriate circumstances, continuous sutures can be performed with greater ease, resulting in anastomosis that is as patent as that performed with interrupted sutures.

A Case of End-Stage Renal Disease With Hemifacial Swelling

A 64-year-old male, with end-stage renal disease on maintenance hemodialysis twice a week for the last two years, presented with swelling over the left half of his face, left side of the neck, and left upper limb for two months. The vascular access for hemodialysis was the left brachiocephalic arteriovenous (AV) fistula. There was no history of insertion of a dialysis catheter on the left side of the neck. Physical examination showed dilated and tortuous veins over the left side of his chest and left arm with normal-functioning AV fistula. Computed tomography (CT) venogram revealed narrowing in the left brachiocephalic vein and cephalic vein with multiple collaterals in the left upper limb and shoulder region. Ballon angioplasty was done across the stenotic segments, and a good flow was achieved with no remnant stenosis. This is a rare presentation as there was no history of cannulation of left-sided central vessels.

Cerebral hemorrhage due to intracranial venous reflux associated with left brachiocephalic vein occlusion in a hemodialysis patient

Background:

Although central venous occlusion is sometimes seen in hemodialysis (HD) patients, neurological symptoms due to intracranial venous reflux (IVR) are extremely rare.

Case Description:

We present a case of a 73-year-old woman with cerebral hemorrhage due to IVR associated with HD. She presented with lightheadedness and alexia, and was diagnosed with subcortical hemorrhage. Venography through the arteriovenous graft showed occlusion of the left brachiocephalic vein (BCV) and IVR through the internal jugular vein (IJV). It is extremely rare that IVR occurs and causes neurological symptoms. This is because that there is the presence of a valve in the IJV and the communication between the right and left veins through the anterior jugular vein and thyroid vein. Percutaneous transluminal angioplasty for the left obstructive BCV was performed, but the obstructive lesion was only slightly improved. Hence, shunt ligation was performed.

Conclusion:

When IVR is found in HD patients, central veins should be confirmed. Early diagnosis and therapeutic intervention are desirable when neurological symptoms are present.

Percutaneous superior vena cava puncture for hemodialysis catheter placement

OBJECTIVE

Central venous occlusion (CVO) refractory to endovascular angioplasty is a critical challenge that threatens hemodialysis vascular access. In the present study, we evaluated the efficacy and safety of tunneled, cuffed central venous catheter (tCVC) placement via percutaneous superior vena cava (SVC) puncture in patients with refractory CVO.

METHODS

Patients requiring maintenance hemodialysis with refractory CVO who had undergone percutaneous SVC puncture and tCVC insertion at a university-affiliated hospital from January 2016 to June 2020 were included. The patients were followed up until May 2021. The demographic information, complications, and catheter patency were analyzed.

RESULTS

A total of 205 patients (105 women [51.2%]; mean age, 61 ± 15 years) were included. The SVC puncture and tCVC insertion were successfully performed in 194 patients, for a technical success rate of 94.6%. One patient had experienced a pleura injury and hemothorax and had required urgent thoracotomy. A total of 37 patients had presented with mild chest pain and were prescribed oral nonsteroidal anti-inflammatory drugs. During follow-up of the 194 patients with a successful procedure, catheter dysfunction due to thrombosis had occurred in 66 patients, catheter malposition had occurred in 5 patients, and catheter-related blood stream infection had developed in 6 patients. The 3-year primary patency rate was 64.2%, and the 3-year secondary patency rate was 76.3%.

CONCLUSIONS

A tCVC placed through a percutaneous SVC puncture had a satisfactory technical success rate and long-term patency rate in patients requiring hemodialysis, providing an optional vascular access for those with exhausted central vein resources. SVC puncture also avoided the use of left-sided catheters and preserved central vein resources. Caution should be given to avoid potential complications such as pleura injury and hemothorax.

Pathology of catheter-related complications: what we need to know and what should be discovered

Despite the considerable efforts made to increase the prevalence of autogenous fistula in patients on hemodialysis, tunneled cuffed catheters are still an important access modality and used in a high percentage of the hemodialysis population. However, because of the conundrum posed by tunneled cuffed catheters, patients can develop a multitude of complications, including thrombosis, infections, formation of a fibrin sheath, and central vein stenosis, resulting in increased morbidity and mortality as well as placing a heavy burden on the healthcare system. However, with an increasing number of studies now focusing on how to manage these catheter-related complications, there has been less translational research on the pathology of these complications. This review of the most recent literature provides an update on the pathological aspects of catheter-related complications, highlighting what we need to know and what is yet to be discovered. The future research strategies and innovations needed to prevent these complications are also addressed.

Arteriovenous Hemodialysis Access Stenosis Diagnosed by Duplex Doppler Ultrasonography: A Review

Arteriovenous fistula (AVF) is currently the hemodialysis access with the longest life expectations for the patients. However, even the AVF is at risk for many complications, especially the development of stenosis. The latter can not only lead to inadequate hemodialysis but also lead to AVF thrombosis. Duplex Doppler ultrasonography is a very precise method, in the hands of experienced professionals, for the diagnosis of AVF complications. In this review, we summarize the ultrasound diagnostic criteria of significant stenoses and their indication for procedural therapy.

Challenging, Safe, and Effective Use of External Iliac Vein for Insertion of Tunneled Cuffed Hemodialysis Catheters: A Single-Center Prospective Study

Background

Providing well-functioning vascular access is crucial for patients undergoing chronic hemodialysis. Peripheral arteriovenous fistulas and grafts are the preferred accesses in hemodialysis patients. Patients with bilateral obstruction of internal jugular veins and subclavian veins require a suitable vascular access. Thus, the insertion of iliac vein tunneled cuffed catheters (TCCs) by interventional nephrologists may be a good option for these patients. We aimed to evaluate the outcomes of iliac vein TCCs in patients lacking other vascular options.

Methods

80 tunneled cuffed hemodialysis catheters were inserted through the iliac veins of 80 patients with an end-stage kidney disease. Catheter insertion was guided by Doppler ultrasonography followed by plain radiography to detect the catheter tip and exclude complications.

Results

The insertion success rate was 100%. 25 patients developed catheter-related infections. The mean survival time per catheter was 328 days. At the end of the study, 40 catheters were still functioning, 15 patients were shifted to continuous ambulatory peritoneal dialysis and 5 patients were referred to the interventional radiology department for insertion of transhepatic inferior vena cava tunneled catheters. Resistant catheter-related infection was the main cause of catheter removal in 11 patients (17.5%) in this study. Catheter malfunction was the second most common cause of catheter removal in 9 patients (11.25%).

Conclusion

This study concluded that iliac vein TCCs can provide suitable vascular access in hemodialysis patients with bilateral obstruction of internal jugular veins and subclavian veins.

Drug-Coated Balloons for the Dysfunctional Vascular Access: An Evidence-Based Road Map to Treatment and the Existing Obstacles

An underlying stenosis within the venous limb of a hemodialysis access circuit is the main etiology for graft and fistula dysfunction as well as other symptoms such as arm, breast, and neck swelling. Treatment options for both peripheral and central venous stenoses include plain old balloon angioplasty, angioplasty with drug-coated balloons, and stenting. This article discusses the current evidence for the use of drug-coated balloon angioplasty in this patient population.

Hemodialysis Catheters: Update on Types, Outcomes, Designs and Complications

Hemodialysis catheters (HDCs) are an essential part of kidney replacement therapy. While these catheters are considered only the bridge to long-term vascular access such as arteriovenous fistulas and grafts, they are associated with significant morbidity and mortality and subsequent increased health care expenditures. However, despite these risks, a large proportion of end stage kidney disease population initiates dialysis using these catheters. The pathogenicity of HDCs stems from its invasive nature to the venous vasculature tree resulting in both mechanical and infectious complications. Therefore, the wide use these catheters in dialysis population and the associated complications necessitated continuous innovations in the catheter material, design, and placement techniques. This review provides an update on the catheter types, catheter tip designs, and the new technologies and innovations aimed to improve the catheter functionality and mitigate its related complications.

One-year outcomes and predictive factors for primary patency after stent placement for treatment of central venous occlusive disease in hemodialysis patients

Objective:

The study purpose was to determine the outcomes and factors predictive of primary stent patency for the treatment of central venous occlusive disease (CVOD) in hemodialysis patients.

Methods:

Data of 71 patients with CVOD treated with stent placement from January 2012 to December 2017 were analyzed. Univariate and multivariate analysis was performed to determine factors associated with stent patency. Adverse events related to stent placement were also examined.

Results:

The median primary patency duration of the 71 patients was 16 ± 2.2 months. The cumulative 3-, 6-, 9-, and 12- month primary patency rates were 93%, 72%, 55%, and 51%, respectively. Independent predictors of longer primary patency were vessel diameter > 12 mm, the use of a covered stent, and absence of vessel calcifications. Median primary patency of covered stents was 21 months as compared with only 10 months for bare stents (p < 0.001). Procedure-related adverse events occurred in 17 patients (21.8%), and four events (5.1%) required medical intervention. No life-threaten complications occurred.

Conclusions:

A vessel diameter > 12 mm, the use of a covered stent, and no vessel calcifications are independently associated with a higher primary patency rate after treatment of CVOD in hemodialysis patients.

Value of a quantitative model of axillary venous blood flow spectrum for the detection of central venous stenosis in patients undergoing hemodialysis via radiocephalic arteriovenous fistula

Background

Central venous stenosis (CVS) of radiocephalic arteriovenous fistula (RCAVF) affects RCAVF function and longevity. Ultrasound screening for CVS is limited by acoustic window. Herein, we analyzed the quantitative axillary venous (AxV) spectrum in hemodialysis patients via RCAVF, and constructed central venous stenosis index (CVSI) model based on the spectrum parameters to early detect resting asymptomatic CVS.

Methods

From August 2017 to May 2021, stage 5 chronic kidney disease (CKD) patients dialysed via RCAVF at the First Affiliated Hospital of Fujian Medical University were included in this study. No CVS-related symptoms were found and the pulsation at the arteriovenous anastomosis was normal. However, the patients had the sensation of swelling in the ipsilateral upper limb during dialysis; the venous pressure advanced upon the completion of dialysis; or both (n=52). The inclusion criteria were as follows: (I) Ultrasound (US) showed that the temporal phases of the AxV spectrum were “normal”; and (II) CVS was confirmed by digital subtraction angiography (DSA). The exclusion criteria were as follows: (I) stent placement; (II) multiple stenosis; and (III) placement of central venous catheter. A total of 37 patients participated in the analysis. Eighteen patients were included in the CVS group, and 19 cases without CVS were included in the control group. Independent sample t-test was used to screen each parameter of the AxV spectrum, and a CVSI model was constructed by principal component analysis (PCA). The receiver operating characteristic curve (ROC) was applied to analyze the diagnostic value of CVSI.

Results

According to the independent sample t-test, 9 parameters were found to have statistical significance (all P<0.05); they were analyzed by PCA, and the CVSI model was constructed. The ROC showed that CVSI had diagnostic value for CVS. When the cut-off value of CVSI was 7.13, the maximum value of the Youden index was 0.842, with a sensitivity of 100% and a specificity of 84.2%.

Conclusions

The CVSI helps to early detect resting asymptomatic CVS and dramatically increases the detection rate of CVS.

Migration of covered stents in thoracic central vein obstruction procedures in patients with hemodialysis: Case report and literature review

OBJECTIVE

The objective of the study is to present a case of hemodialysis in which the covered stent that had migrated into the right ventricle was retrieved by exploratory thoracotomy, and to review the literature on the diagnosis and treatment of stent migration in thoracic central vein obstruction (TCVO) procedures for hemodialysis patients.

METHOD

A systematic search of the PubMed database was performed to identify clinical presentations, imaging strategies, stent types, and treatment modalities for stent migration in hemodialysis patients.

RESULTS

A total of 14 case reports on stent migration in TCVO procedures for hemodialysis patients were included and analyzed. Ten cases included migration to the cardiac chambers and the remainder migration to the pulmonary artery. The common symptoms of stent migration in TCVO procedures are reported to be chest pain and dyspnea, while three of the cases studied involved no symptoms. Echocardiography, chest X-ray, and computed tomography are the commonly used methods for the diagnosis of stent migration and identification of the precise positioning of the stent. Stent migration to the right subclavian or innominate veins was the most prevalent case (seven cases). All were bare stents. Seven cases involved retrieval by interventional surgery, while four cases involved retrieval by open heart surgery. However, there were three cases in which the "wait-and-see" approach was adopted since the patients were asymptomatic.

CONCLUSIONS

Stent migration in TCVO procedures is a rare but extremely serious complication. The causes are not fully understood. The current treatment strategies include interventional surgery, open heart surgery, and the "wait-and-see" approach.

Tratamento endovascular de doença oclusiva venosa central com fístula arteriovenosa funcionante

Resumo Contexto A maior sobrevida dos doentes dialíticos somada à incapacidade de obtenção de órgãos suficientes para atender a demanda, bem como à dificuldade de acesso aos serviços de saúde, levou ao aumento da fila para transplante e ao prolongamento do tempo de utilização do acesso venoso central para hemodiálise. A etiologia mais comum de estenose de veia central é o acesso venoso central prolongado, pelas lesões intimais decorrentes da presença do cateter. Objetivos Avaliar resultados de angioplastia para tratamento de doença oclusiva venosa central com fístula arteriovenosa periférica funcionante. Métodos Estudo tipo coorte retrospectivo com revisão de prontuários de 47 doentes com lesões estenóticas ou oclusivas. A avaliação dos doentes foi realizada em 30 dias, 6 meses e 1 ano após a recanalização ou correção da estenose com ATP ou ATP/aplicação de stent. Resultados Lesões estenóticas foram encontradas em 25 doentes (53%), e oclusões, em 22 (47%) doentes. A angioplastia percutânea transluminal (ATP) com stent foi utilizada em 64% dos doentes, e angioplastia isolada com balão, em 36% deles. A análise de resultados clínicos mostrou elevada taxa de melhora clínica precoce (30 dias) em 82% dos doentes (intervalo de confiança [IC] 71-93%). Após 1 ano de seguimento, a taxa de perviedade primária foi de 57%, e a taxa de perviedade primária assistida foi de 72% (IC 57-84%). Conclusão O tratamento endovascular das estenoses ou oclusões de veia central sugere melhora clínica dos sintomas e taxas adequadas de perviedade no período de 1 ano, apesar da limitação no tamanho amostral.

Transient bacteremia promotes catheter-related central venous thrombosis through neutrophil extracellular traps

Formation of intravenous catheter-related thrombosis leads to central venous stenosis in patients requiring renal replacement therapy or chemotherapy infusion, yet the triggering or mechanisms remain unclear, especially in patients without symptoms of infection. In this study, we found that neutrophil extracellular traps (NETs) could be detected in the fibrin sheaths from dialysis patients without clinical manifestations of infection. Confocal microscopy revealed bacteria imbedded in NETs in the fibrin sheaths. Thirty-nine of 50 (78%) fibrin sheath specimens contained bacteria detectable by 16S ribosomal RNA genome typing with a predominance of Staphylococcus aureus (69%). In rat models, transient bacteremia of S. aureus induced NETs in enlarged fibrin sheaths, and treatment with DNase I alone significantly reduced both NET and fibrin sheath formation surrounding the catheter. Therefore, transient bacteremia could be a silent trigger that induces NET-related immunothrombosis enhancing catheter-related central venous stenosis.

Comparison of Management for Central Venous Stenosis With or Without Previous Catheter Placement

Objective: To compare central venous stenosis/occlusion with or without previous jugular catheter placement history.

Methods: Data of patients with central vein stenosis/occlusion receiving endovascular intervention in our hospital from January 2015 to December 2018 were collected and analyzed.

Results: Twenty-nine patients with previous jugular catheter placement history (CVC group) and 33 patients (excluded two with technical failure) without such history (non-CVC group) are included in this study. Previous jugular catheter placement history raised the risk of postintervention recurrence 1.02 times (CVC group vs. non-CVC group, HR = 2.02 95%CI: 0.91–4.48). The primary patency rate at 6, 12, 18, and 24 months was 76.9, 54.2, 45.5, and 25.0% separately in the CVC group and 80.6, 70.0, 67.9, and 44.4% separately in the non-CVC group. The assisted primary patency rate at 6, 12, 18, and 24 months was 92.3, 91.7, 86.4, and 68.8% separately in the CVC group and 93.5, 90.0, 82.1, and 61.1% separately in the non-CVC group. Patients in the CVC group received a higher frequency of reintervention (0.7 times/year/patient vs. 0.3 times/year/patient). There was no significant difference in the assisted primary patency rate between the two groups. Different primary interventions (angioplasty alone, bare metal stent, stent graft) did not affect primary patency and assisted primary patency, but percutaneous transluminal stenting (PTS) with a bare metal stent had a significant lower primary patency rate between 3 and 24 months compared with PTS with a stent graft (p = 0.011).

Conclusion: Central venous stenosis/occlusion with a previous jugular catheter placement history develops symptoms earlier and had a worse prognosis after endovascular intervention. More efforts are needed to carry out end-stage kidney disease life plan to reduce the harm of evitable catheter placement.

A retrospective cohort study comparing high and low balloon inflation pressure on technical success and patency for treating central venous lesions in patients on chronic hemodialysis

Background

We aimed to analyze the success rates and the access patency rates at 12 months between patients on chronic hemodialysis with symptomatic central venous stenosis (CVS) or occlusion (CVO), receiving high or low balloon inflation pressure for treatment.

Methods

We performed a retrospective study in which angioplasty balloons were inflated using a low-pressure or a high-pressure for the management of hemodialysis patients with CVS/CVO. The outcomes of this study were the success rate and the access patency rates at 12 months after balloon angioplasty, and the differences between groups were compared.

Results

We included a total of 74 patients on hemodialysis and assigned them to the low-pressure or the high-pressure groups. Success rates in patients of the high-pressure group (94.12%) were higher than those in patients of the low-pressure group (67.50%) (p = 0.005). With a total of 59 patients with technical success, at 6 and 12 months after angioplasty, the rates of access patency in the low-pressure group were 68 and 48%, respectively; on the other hand, the primary patency rates in the high-pressure group were 86.67% (6-months) and 76.67% (12-months). The 6 and 12 months post-interventional patency rates were higher in patients of the high-pressure group than those in patients of the low-pressure group (p = 0.10 at 6 months and p = 0.03 at 12 months).

Conclusions

Compared to balloon angioplasty using a low inflation pressure, hemodialysis patients with CVS/CVO receiving angioplasty using a high inflation pressure have significantly higher technical success and 12-month patency rates.

Central Venous Disease Increases the Risk of Microbial Colonization in Hemodialysis Catheters

Objectives: Tunneled-cuffed catheters (TCCs) are widely used in maintenance hemodialysis patients. However, microbial colonization in catheters increases the likelihood of developing various complications, such as catheter-related infection (CRI), catheter failure, hospitalization, and death. Identification of the risk factors related to microorganism colonization may help us reduce the incidence of these adverse events. Therefore, a retrospective analysis of patients who underwent TCC removal was conducted.

Methods: From a pool of 389 adult patients, 145 were selected for inclusion in the study. None of the patients met the diagnostic criteria for CRI within 30 days before recruitment. The right internal jugular vein was the unique route evaluated. The catheter removal procedure was guided by digital subtraction angiography. Catheter tips were collected for culture. Biochemical and clinical parameters were collected at the time of catheter removal.

Results: The average age of this cohort was 55.46 ± 17.25 years. A total of 45/145 (31.03%) patients were verified to have a positive catheter culture. The proportions of gram-positive bacteria, gram-negative bacteria, and fungi were 57.8, 28.9, and 13.3%, respectively. History of CRI [odds ratio (OR) = 2.44, 95% confidence interval (CI) 1.09 to 5.49], fibrin sheath (OR = 2.93, 95% CI 1.39–6.19), white blood cell (WBC) count ≥5.9 × 10⁹/l (OR = 2.31, 95% CI 1.12–4.77), moderate (OR = 4.87, 95% CI 1.61–14.78) or severe central venous stenosis (CVS) (OR = 4.74, 95% CI 1.16–19.38), and central venous thrombosis (CVT) (OR = 3.41, 95% CI 1.51–7.69) were associated with a significantly increased incidence of microbial colonization in a univariate analysis. Central venous disease (CVD) elevated the risk of microbial colonization, with an OR of 3.37 (1.47–7.71, P = 0.004). A multivariate analysis showed that both CVS and CVT were strongly associated with catheter microbial colonization, with ORs of 3.06 (1.20–7.78, P = 0.019) and 4.13 (1.21–14.05, P = 0.023), respectively. As the extent of stenosis increased, the relative risk of catheter microbial colonization also increased. In patients with moderate and severe stenosis, a sustained and significant increase in OR from 5.13 to 5.77 was observed.

Conclusions: An elevated WBC count and CVD can put hemodialysis patients with TCCs at a higher risk of microbial colonization, even if these patients do not have the relevant symptoms of infection. Avoiding indwelling catheters is still the primary method for preventing CRI.

Sharp recanalization for treatment of central venous occlusive disease in hemodialysis patients

BACKGROUND

The purpose of the present study was to evaluate the technical feasibility and safety of sharp recanalization for central venous occlusive disease (CVOD) in patients requiring hemodialysis.

METHODS

Patients with CVOD requiring hemodialysis who had undergone endovascular recanalization using sharp devices, including the stiff end of a guidewire, Chiba needle, or RUS-100 to cross occluded segments after conventional techniques had failed were included. The needle was guided toward a target placed at the opposite end of the occlusion. Although the guidewire was passed though the occlusion, subsequent procedures such as percutaneous transluminal angioplasty could be performed.

RESULTS

A total of 27 sharp recanalization procedures in 25 patients were performed. Two attempts failed, 1 patient had undergone two separate successful procedures, and 23 procedures in 23 patients were successful. The overall technique success was 92.6%. The stiff end of a guidewire was the first choice for all the procedures, and recanalization was achieved in 18 patients (66.7%). A Chiba biopsy needle was used in six procedures (22.2%), with 100% technical success. A RUPS-100 set was used in two procedures (7.4%), with one aborted because of concern for complications. The occlusion was subsequently crossed using a Chiba needle. Four minor adverse events (two of mediastinal hematoma and two of chest pain) had occurred, and two major adverse events (pericardial tamponade and acute pleural effusion in one patient [4%], treated with the guidewire stiff-end technique, who recovered after drainage) had occurred.

CONCLUSIONS

Sharp recanalization is safe and feasible with high technical success for CVOD in patients requiring hemodialysis who cannot be recanalized using conventional techniques.

Paclitaxel-Coated Balloons for the Treatment of Symptomatic Central Venous Stenosis in Vascular Access: Results From a European, Multicenter, Single-Arm Retrospective Analysis

INTRODUCTION

This was a European, multicenter, investigator-initiated and run, single-arm retrospective analysis to assess the safety and the clinical benefit of the use of paclitaxel-coated balloon (PCB) for the treatment of symptomatic central venous stenosis (CVS).

MATERIALS AND METHODS

Eleven centers from 7 countries across Europe, submitted 86 cases performed during the period between October 2015 and June 2018. Minimum follow-up was 6 months. Patient baseline demographics and procedural details were collected. Mean age was 62.6 years (SD 15.2 years). Median vascular access age was 3.0 years (IQR 1.2-4.8 years). A total of 55 were arteriovenous fistulas (64%) the rest arteriovenous grafts (31/86, 36%). Vessels treated were 43 subclavian veins, 42 brachiocephalic veins and 1 superior vena cava. Median drug-coated balloon diameter was 10 mm (IQR 8-12 mm). Primary outcome measures were clinically assessed intervention-free period (IFP) of the treated segment at 6 months and procedure-related minor and major complications. Secondary outcome measures included access circuit survival, patient survival, and the investigation of independent factors that influence the IFP.

RESULTS

IFP was 62.7% at 6 months. Median patient follow-up time was 1.0 year (IQR 0.5-2.2 years). There was 1 minor complication (1/86; 1.2%) and no major complications. Access circuit survival was 87.7% at 6 months. Patient survival was 79.7% at 2 years according to Kaplan-Meier survival analysis. Higher balloon diameters significantly favored IFP [HR 0.71 (0.55-0.92), p=0.006; 5-7 mm group vs 8-12 mm group, p=0.025].

CONCLUSION

In this analysis, use of PCBs for the treatment of symptomatic CVS was safe. Efficacy was comparable to previous trials. Increased balloon size had a significant effect on patency rates.

Hemodialysis catheter integrity during mechanical power injection of iodinated contrast medium for computed tomography angiography

PURPOSE

CT angiography (CTA) requires vascular access with flow rates of 5-7 mL/s. Hemodialysis (HD) is performed at 6-10 mL/s. The purpose of our study is to evaluate the structural integrity of HD catheters in the administration of contrast media via a mechanical power injector under varying conditions.

METHODS

Four HD catheters were evaluated in an in vitro study. Tested were contrast media type (iopamidol 300 and 370 mgI/mL), temperature (25 and 37 °C), catheter diameter (14 Fr to 16 Fr all with double-lumen capacity), catheter length (19-32 cm), and simultaneous double-lumen or single-lumen injection within each of the catheters. Peak plateau pressures (psi) were recorded with flow rates from 5 to 20 mL/s in 5 mL/s increments. In total, 864 unique injections were performed.

RESULTS

No catheter failure (bulging/rupture) was observed in 864 injections. Maximum pressure for single-lumen injection was 51.7 psi (double-lumen: 26.3 psi). Peak pressures were significantly lower in simultaneous double-lumen vs. single-lumen injections (p < 0.001) and low vs. high viscosity contrast media (p < 0.001). Neither larger vs. smaller diameter lumens (p = 0.221) nor single-lumen injection in arterial vs. venous (p = 0.834) were significantly different.

CONCLUSION

HD catheters can be used to safely administer iodinated contrast media via mechanical power injection in in vitro operating conditions. Maximum peak pressure is below the manufacturer's 30 psi limit at flow rates up to 20 mL/s in double-lumen injections and up to 10 mL/s in single-lumen injections, which is higher than the usual maximum of 8 mL/s for CT angiography in clinical settings.

New Devices and Technologies for Hemodialysis Vascular Access: A Review

In the United States, hemodialysis remains the most common treatment modality for kidney failure, chosen by almost 90% of incident patients. A functioning vascular access is key to providing adequate hemodialysis therapy. Recently, major innovations in devices and technology for hemodialysis vascular access care have rapidly changed the landscape. Novel endovascular devices for creation of arteriovenous fistulas may offer a solution to the barriers encountered in initiating maintenance hemodialysis with a permanent vascular access rather than a central venous catheter (CVC). Furthermore, in the prevalent hemodialysis population, the minimally invasive endovascular arteriovenous fistula procedure should help improve long wait times for vascular access creation, which remains a major barrier to reducing CVC dependence. Bioengineered grafts are being developed and may offer another option to polytetrafluoroethylene grafts. Early studies with these biocompatible grafts are promising, as additional studies continue to evaluate their clinical outcomes in comparison to cryopreserved or synthetic options. Prolonging the vascular access patency with appropriate use of devices such as drug-coated balloons and stent grafts may complement the novel techniques of creating arteriovenous access. Finally, innovative solutions to treat stenosed and occluded thoracic central veins can provide an approach to creating a vascular access and allow patients with exhausted vasculature to remain on hemodialysis. The robust developments in hemodialysis vascular access are likely to change practice patterns in the near future.

Thoracic outlet decompression for subclavian venous stenosis after ipsilateral hemodialysis access creation

OBJECTIVE

Central venous stenosis is one of the most challenging complications in patients requiring hemodialysis. Venous thoracic outlet syndrome is an underappreciated cause of central venous stenosis in patients requiring dialysis that can result in failed percutaneous intervention and loss of a functioning dialysis access. Limited data exist about the safety and outcomes of first rib resection in patients requiring hemodialysis, and the results have been confounded by the various surgical approaches used. The purpose of the present study was to evaluate the safety, operative outcomes, and patency of the existing dialysis access after transaxillary thoracic outlet decompression.

METHODS

A retrospective medical record review was performed from January 2008 to December 2019 of patients who had undergone thoracic outlet decompression for subclavian vein stenosis with ipsilateral upper extremity hemodialysis access. The baseline characteristics and comorbidities were reviewed. The operative and postoperative course were evaluated. The survival and patency rates were analyzed using the life-table method and Kaplan-Meier curve.

RESULTS

A total of 18 extremities in 18 patients were identified. Their mean age was 59 ± 11 years, and 89% were men. A total of 13 fistulas and 5 grafts were included. All patients had undergone repair via a transaxillary approach. First rib resection, anterior scalenectomy, and circumferential venolysis were performed in all 18 patients. The mean operative time was 99 ± 19 minutes, with an estimated blood loss of 78 ± 66 mL. The median length of stay was 2 days. No patient had died at 30 days. The survival rate at 1 year was 83%. The primary, primary-assisted, and secondary patency at 1 year were 42%, 69%, and 93%, respectively.

CONCLUSION

Thoracic outlet decompression via the transaxillary approach is a technically feasible and safe operation in patients with ipsilateral upper extremity hemodialysis access. Patients with threatened dialysis access due to subclavian vein stenosis should be carefully evaluated for possible extrinsic compression at the costoclavicular junction. These patients might benefit from transaxillary first rib resection, scalenectomy, and venolysis.

Hemodialysis as a Risk Factor for Lower Right Internal Jugular Stenosis in Cardiac Surgery Patients: A Retrospective Single-Center Study

Lower right internal jugular vein (RIJ) stenosis has been reported as a common cause of RIJ catheterization failure. However, the risk factors for lower RIJ stenosis in patients undergoing cardiac surgery is unclear. We reviewed the electronic medical records of all adult patients who had undergone cardiac operations in a single tertiary university hospital from January 2014 to January 2016. Patients were excluded if they were lack of preoperative contrast-enhanced chest computed tomography (CT) studies. Lower RIJ stenosis was defined as a ratio of cross-sectional area at the smallest level to cross-sectional area at the largest level less than 25%. Multivariable logistic regression analyses were used to investigate the risk factors for lower RIJ stenosis. A sensitivity analysis was also conducted using a cross-sectional area ratio of under 20%. The analysis included 889 patients, and the incidence of lower RIJ stenosis was 3.9%. The multivariable logistic regression analyses revealed that hemodialysis was an independent risk factor for lower RIJ stenosis (OR, 3.54; 95% CI, 1.472–8.514). Sensitivity analysis provided that hemodialysis (OR, 10.842; 95% CI, 3.589–32.75) was a significant predictor of cross-sectional area ratio <20%. Preoperative hemodialysis are significantly associated with an increased risk of lower RIJ stenosis in patients undergoing cardiac surgery. Extra care is needed during central venous catheterization in hemodialysis patients undergoing cardiac surgery.

A systematic review of venoplasty versus stenting for the treatment of central vein obstruction in ipsilateral hemodialysis access

OBJECTIVE

This review examines the evidence regarding treatment of central vein obstruction (CVO) in the setting of ipsilateral hemodialysis access. The aim of this work is to identify whether long-term venous patency after central vein stenting is superior compared with balloon venoplasty. To date, there are no evidence-based guidelines to direct the management of CVO in the setting of ipsilateral hemodialysis access.

METHODS

An extensive systematic database search was performed using Medline, Embase, and the Cochrane Databases to identify all articles published from January 2000 to November 2019 comparing the management of CVO with venoplasty and/or stenting in the setting of ipsilateral hemodialysis access fistulae/grafts.

RESULTS

There were 655 patients with 456 stenoses and 208 occlusions who were treated; 288 underwent venoplasty and 345 underwent stenting. Twenty-two patients failed intervention owing to an inability to traverse the occlusion. The most affected vein was the brachiocephalic vein. A superior primary patency (PP) is noted in those treated with stenting compared with venoplasty in the first 2 years. Overall, both treatments are suboptimal demonstrating a 12-month PP rate of less than 60%. Assisted PP and secondary patency rates were similar for both venoplasty and stenting with a 12-month secondary patency rate of 77.8% to 91.6% for venoplasty and 89.6% to 98.4% for stenting. Periprocedural and long-term complications were rare for both interventions, occurring in 2% of patients.

CONCLUSIONS

Although both treatments demonstrated poor patency rates, greater PP is noted for stenting in the first 2 years. Coupled with low complication rates, this finding highlights a potential benefit of stenting as a first-line treatment for CVO. Allowing for the overall poor quality of current studies, even this short-term improvement in PP may benefit patients undergoing hemodialysis. Further research with randomised control trials as well as assessment of adjuvant techniques such as drug-coated stents and balloons, anticoagulant therapy, and the role of intravascular ultrasound use is required.

Hybrid angioplasty-catheter placement procedure performed in a hemodialysis patient with central venous obstruction disease. Presentation of a case

Obstruction or occlusion of the central veins (Central venous disease, CVD) represents a major complication in hemodialysis patients (HD) limiting central venous access available for a central venous catheter placement. Endovascular treatment with percutaneous transluminal angioplasty (PTA) is the first therapeutic option to restore patency and gain access. This case presents our initial experience of a HD patient with CVD treated with a combination therapy of a balloon PTA to the left brachiocephalic trunk, through the right hepatic vein and standard catheter placement technique to the previously occluded junction of the left internal jugular vein to the left subclavian vein.

Results of Stenting for Central Venous Occlusions and Stenoses in the Hemodialysis Patients

Objectives: We aim to investigate the results of stenting for central venous occlusions and stenoses in the hemodialysis patients.

Methods: Twenty-nine cases treated with endovascular recanalization with deployment of bare metal stent (BMS) for central venous occlusions (24 cases) and recurrent stenoses (5 cases) between 2014 and 2018 were retrospectively analyzed. Results of these procedures including success rate, operative time, estimated blood loss, morbidity, primary patency, assisted primary patency and freedom from target-lesion revascularization (TLR) were evaluated.

Results: Nine lesions were in brachiocephalic vein (Occlusion/Stenosis: 8/1) and 20 lesions were in subclavian vein (Occlusion/Stenosis: 16/4). Procedural success was 94% (29/31 cases) and operation time/estimated blood loss was 68±39 min/28±54 g. Symptom were relieved or disappeared in all successful cases. Morbidity (extravasation of contrast medium) was 3% (1/29). During the period of observation, 1 stent fracture with occlusion and 1 stent migration to periphery were recognized. 1-year primary patency, freedom from TLR, and assisted primary patency were 40% (median patent time: 256 days), 67% (median patent time: 524 days), and 77%, respectively.

Conclusion: Stenting for central venous occlusions and stenoses in the hemodialysis patients is safe and durable treatment option. However, considering its off-label use and potential hazard including vessel rupture, stent migration, and stent fracture, the indication for BMS deployment should be conservative, and interventionist should be well acquainted with prevention and measures to these complications. (This is a translation of Jpn J Vasc Surg 2019; 28: 193–198.)

Angiectasia of the parietal pleura in a hemodialysis patient with central venous stenosis and bloody pleural effusion: a case report

Pleural effusion in hospitalized patients with long-term hemodialysis (HD) has been frequently reported. The most common causes of unilateral pleural effusions include hypervolemia, parapneumonic, uremic effusion, and malignancy. In contrast, central venous stenosis (CVS) has rarely been shown to result in pleural effusion. CVS is often diagnosed by percutaneous angiography, yet there are no reports of cases where percutaneous angiography missed CVS and instead intrathoracic endoscopy was performed. Herein, we report a case of CVS with angiectasia of the parietal pleura detected on intrathoracic endoscopy. A 62-year-old man with HD presented with massive unilateral pleural effusion. Although the cause of pleural effusion was suspected to be CVS, percutaneous angiography did not show apparent stenosis, and as a result, other potential causes of bloody effusion were investigated. The intrapleural cavity was assessed using intrathoracic endoscopy, which revealed angiectasia and no malignancy. As these findings might be suggestive of congestive and dilated vessels with venous stenosis or occlusion, 3D-computed tomography (CT) scans were performed instead of percutaneous angiography to determine whether a stenosis or occlusion was present. Brachiocephalic vein stenosis was found near the aortic arch. CVS was treated through ligation of the arteriovenous fistula (AVF), resulting in a dramatic decrease in the left pleural effusion. This case would suggest that CVS should be suspected when angiectasia of the parietal pleura is observed in HD patients. In addition, the benefit of utilizing 3D-CT should be considered when HD patients present with a unilateral hemothorax on the same side as that of the AVF, particularly when on the left side.

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 24 months with diagnostic fistulography. Fourteen patients initially underwent 15 BMS placements. In the follow-up period (range, 118-976 days), 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 ± 43 days. For salvage, 14 stent-grafts were placed in segments with recalcitrant restenosis of a CVS stent. Within 1.25 ± 0.72 days after stent-graft placement, patients who initially presented with symptomatic venous hypertension reported complete resolution. The median primary access survival (mean, 1183 ± 312 days) 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 18 months was 100%, and it was 85.7% at 24 months. The secondary access patency rate was 92.9% at 24 months. 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.

A mouse model of stenosis distal to an arteriovenous fistula recapitulates human central venous stenosis

Objective

Central venous stenosis (CVS) is a major cause of arteriovenous fistula (AVF) failure. However, central veins are relatively inaccessible to study with conventional Doppler ultrasound methods. To understand mechanisms underlying AVF failure owing to CVS, an animal model was established that creates a stenosis distal to an AVF. We hypothesized that this mouse model will show comparable morphology and physiology to human CVS.

Methods

An aortocaval fistula was created between the distal aorta and inferior vena cava (IVC); a stenosis was then created distal to the fistula by partial IVC ligation. Sham-operated animals, AVF without venous stenosis, and venous stenosis without AVF were used as controls. Physiologic properties of the IVC, both upstream and downstream of the stenosis, or the corresponding sites in models without stenosis, were assessed with ultrasound examination on days 0 to 21. The spectral broadening index was measured to assess the degree of disturbed shear stress. The IVC was harvested at day 21 and specimens were analyzed with immunofluorescence.

Results

The IVC diameter of mice with an AVF and stenosis showed increased upstream (P = .013), but decreased downstream diameter (P = .001) compared with mice with an AVF but without a stenosis, at all postoperative times (days 3-21). IVC wall thickness increased in mice with an AVF, compared with IVC without an AVF (upstream of stenosis: 13.9 μm vs 11.0 μm vs 4.5 μm vs 3.9 μm; P = .020; downstream of stenosis: 6.0 μm vs 6.6 μm vs μm 4.5 μm vs 3.8 μm; P = .002; AVF with stenosis, AVF, stenosis, sham, respectively). AVF patency significantly decreased in mice with an AVF and stenosis by day 21 (50% vs 90%; P = .048). The IVC of mice with AVF and stenosis showed a venous waveform with pulsatility as well as enhanced velocity at and downstream of the stenosis; similar waveforms were observed in a human case of CVS. Downstream to the stenosis, the spectral broadening index was significantly higher compared with mice with AVF alone (1.06 vs 0.78; P = .011; day 21), and there was a trend towards less immunoreactivity of both Krüppel-like factor 2 and phosphorylated-endothelial nitric oxide synthase compared with mice with an AVF alone.

Conclusions

Partial IVC ligation distal to a mouse aortocaval fistula alters the fistula diameter and wall thickness, decreases patency, and increases distal disturbed flow compared with fistulae without a distal stenosis. Our mouse model of stenosis distal to an AVF may be a faithful representation of human CVS that shows similar morphology and physiology, including disturbed shear stress.

A mouse model of venous stenosis distal to an arteriovenous fistula shows similar Doppler waveforms as those observed in a human case of central venous stenosis. These mice retain disturbed shear stress in the vein distal to the fistula, characterized by a sustained increase of the spectral broadening index and diminished expression of proteins upregulated by laminar shear stress. This novel mouse model will enable investigation of the physiology and downstream molecular pathways involved in central venous stenosis in humans.

Sharp recanalization of the brachiocephalic vein occlusion through the external jugular vein in hemodialysis patients

Background

Although the internal jugular vein (IJV) is the most widely used puncture site in hemodialysis catheter insertion and central vein angioplasty, the external jugular vein (EJV) offers an alternative vascular access point in cases when the IJV is inaccessible. The present study aims to observe the efficacy and safety of sharp recanalization of the brachiocephalic vein occlusion through the EJV in hemodialysis patients.

Methods

This retrospective study enrolled a cohort of hemodialysis patients who received sharp recanalization of occlusive brachiocephalic vein through the EJV at a university-affiliated hospital between January 2017 and January 2019. The demographic information and clinical outcome data of the patients were collected and analyzed.

Results

A total of 16 hemodialysis patients who received right brachiocephalic vein sharp recanalization through the EJV were analyzed. The technical success rate was 100%. Twelve patients (12/16, 75%), whose EJV-subclavian vein angle (E-S angle) was 60–80 degrees, were successfully recanalized on the first attempt. With the other 4 patients (4/16, 25%), whose E-S angle approached 90 degrees, the brachiocephalic vein was recanalized on the second attempt by elevating the ipsilateral shoulder, therefore decreasing the E-S angle to align the course of the EJV with the brachiocephalic vein. Three minor complications were recorded, including 1 patient with blood continuously oozing from the EJV at the puncture site and 2 patients with mild chest pain. After an average of 10 months of follow-up, the clinical patent rate was 81.25% with no procedure-related complications reported.

Conclusions

Sharp recanalization through the EJV could be an effective and safe alternative treatment for right brachiocephalic vein occlusion in hemodialysis patients if performed by an experienced practitioner. Measuring the angle formed by the EJV and the subclavian vein might provide helpful information for selecting patients.

Hospital Charges Associated with Central Venous Stenosis in Pediatric Patients Requiring Long-Term Central Venous Access

OBJECTIVE

To evaluate the hospital charges associated with central venous stenosis in pediatric patients requiring long-term central venous catheters, via associated charges and hospital length of stay (LOS).

STUDY DESIGN

This institutional review board-approved retrospective review identified pediatric patients with central venous catheters and either short bowel syndrome (SBS) or end-stage renal disease (ESRD) diagnosed between 2008 and 2015 using the Pediatric Health Information System. These 2 cohorts were selected because long-term central venous access is commonly required for survival. Prevalence of central venous stenosis, total number of admissions, procedures, LOS, and associated charges were recorded. Statistical analysis performed with Wilcoxon nonparametric and 2-sample t test with a significance of P < .05.

RESULTS

Of 4952 patients with SBS and 4665 patients with ESRD, 169 (3.4%) patients with SBS and 191 (4.1%) patients with ESRD were diagnosed with central venous stenosis (360 patients total [3.7%]). The cumulative median admissions and LOS was higher in patients with SBS with central venous stenosis (15 admissions and 156 days) vs those without central venous stenosis (5 admissions and 110 days) (P < .001). The cumulative median number of admissions and LOS was higher in patients with ESRD with central venous stenosis (13 admissions and 72 days) vs those without central venous stenosis (7 admissions and 42 days) (P < .001). The mean cumulative charges for patients with SBS with central venous stenosis were higher than for those without central venous stenosis ($1.89 million vs $1.11 million, respectively) (P < .001). Similarly, the mean cumulative charges for patients with ESRD with central venous stenosis were higher than for those without central venous stenosis ($1.17 millions vs $702 000, respectively) (P < .001).

CONCLUSIONS

Pediatric patients with central venous stenosis have significantly higher total charges, imaging charges, number of admissions, and longer LOS. Attention to mitigate the incidence of central venous stenosis in pediatric patients requiring long-term central venous access is warranted.