AbstractSome hemodialysis patients are not suitable for creation of an arteriovenous fistula (AVF) or arteriovenous graft (AVG). However, they can receive a tunneled cuffed central venous catheter (tcCVC), but this carries risks of infection and mortality. We aimed to evaluate the safety and effectiveness of brachial artery transposition (BAT) versus those of tcCVC. This retrospective study evaluated hemodialysis patients who underwent BAT or tcCVC placement because of severe heart failure, hand ischemia, central venous stenosis or occlusion, inadequate vessels for creating standard arteriovenous access, or limited life expectancy. The primary outcome was whole access circuit patency. Thirty-eight patients who underwent BAT and 25 who underwent tcCVC placement were included. One-year patency rates for the whole access circuit were 84.6% and 44.9% in the BAT and tcCVC groups, respectively. The BAT group was more likely to maintain patency (unadjusted hazard ratio: 0.17, 95% confidence interval: 0.05–0.60, p = 0.006). The two groups did not have significantly different overall survival (log-rank p = 0.146), although severe complications were less common in the BAT group (3% vs. 28%, p = 0.005). Relative to tcCVC placement, BAT is safe and effective with acceptable patency in hemodialysis patients not suitable for AVF or AVG creation.
Objectives: Stenting of central venous stenosis to preserve upper extremity hemodialysis access is well-described, though upper extremity complications secondary to these stents are less frequently discussed. Methods: We present the case of a 43-year-old male with a right brachiocephalic fistula who developed symptoms of venous hypertension following placement of a Wallstent for central venous stenosis. Workup demonstrated venous outflow obstruction secondary to stent foreshortening into the right subclavian vein. Results: The Wallstent was removed in a piecemeal fashion using an open surgical technique and a HeRO graft was placed for dedicated fistula outflow with complete relief of the patient’s symptoms. Conclusion: In situations where a stent has migrated and endovascular removal is not possible, individual Wallstent fibers can be removed through a limited venotomy.
Long-term central venous catheters can be associated with central venous stenosis in up to 50% of cases. Central venous stenosis can be managed with central venous stenting which was demonstrated to restore patency and improve suboptimal results after percutaneous transluminal angioplasty. Dislodgment of venous stents into the right side of the heart or the pulmonary artery during stent deployment is one of the most feared complications of this procedure. Percutaneous removal of these migrated stents is the preferred alternative for the more invasive operative intervention, which may be very hazardous in these patients. We report an unusual case of a 52-year-old man on hemodialysis who underwent endovascular stenting to treat a tight stenosis of the right brachiocephalic vein and superior vena cava and suffered from stent migration to the left pulmonary artery, requiring removal by interventional radiologist.
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.
Successful hemodialysis treatment need a well functioning vascular access (VA) allowing two cannulation sites with enough blood flow have minimum adverse events. The expectations, age of the HD population are rising as well as the lack of conventional methods due to central venous exhaustion, we have to choose some complex access, including complex or tertiary vascular access mentioned in 2018 Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS) and the option to abandon the venous circuit in instead of arterial system, including arterial-arterial graft and arterial superficialization. This article report a complicated case of AVF dysfunction, central venous stenosis due to central venous catheter and aortic dissection stent as well as lower extremity arteriosclerosis occlusion, using the simple method of superficialization of enlarged radial artery to maintain hemodialysis.
Background: Although tunneled dialysis catheters (TDC) are far from ideal, they still represent the main form of vascular access for most patients beginning dialysis. Catheters are easy to place and allow patients instant access to dialysis, but regardless of these benefits, catheters are associated with a high incidence of significant complications like bloodstream infections, central venous stenosis, thrombosis, and dysfunction. In the present study, we aim to describe and characterize a swine model of catheter dysfunction and bloodstream infection, that recreates the clinical scenario, to help to serve as a platform to develop therapeutic innovations for this important clinical problem. Methods: Six Yorkshire cross pigs were used in this study. Non-coated commercial catheters were implanted in the external jugular recreating the main features of common clinical practice. Catheters were aseptically accessed twice a week for a mock dialysis procedure (flushing in and out) to assess for and identify catheter dysfunction. Animals were monitored daily for infections; once detected, blood samples were collected for bacterial culture and antibiograms. Study animals were euthanized when nonresponsive to treatment. Tissue samples were collected in a standardized fashion for macroscopic inspection and histological analysis. Results: The data analysis revealed an early onset of infection with a median time to infection of 9 days, 40% of the isolates were polymicrobial, and the average time to euthanasia was 20.16 ± 7.3 days. Median time to catheter dysfunction onset was 6 days post-implantation. Postmortem dissection revealed external fibrin sheath and internal thrombosis as the main causes of catheter dysfunction. There was also evidence of central venous stenosis with positive cells for αSMA, CD68, Ki67, Smoothelin, and Vimentin within the venous neointima. Conclusions: The described model represents a reliable and reproducible large animal model of catheter dysfunction and bloodstream infection, which recreates all the main complications of TDC’s and so could be used as a validated large animal model to develop new therapies for TDC related infection, thrombosis/dysfunction and central venous stenosis.