Outcomes of Wrist-Access Deep Venous Embolization Following Percutaneous Fistula Creation: A Two-Year Single Center Experience.

PURPOSE: During percutaneous arteriovenous (pAVF) fistula creation, deep venous embolization is recommended to encourage superficial venous flow development. The safety of crossing adjacent to the newly formed fistula from wrist venous access has not been established. The purpose of this study was to evaluate the safety and efficacy of antegrade deep venous embolization after creation of the pAVF. MATERIALS: A retrospective analysis was performed of all procedural data related to pAVF creation using the Wavelinq device from October 2019 to November 2021. Patient data from the hospital information systems were collected where the venous access for fistula creation was from the wrist-access (ulnar or radial vein) and where deep venous embolization was performed after forming the fistula and crossing adjacent to the anastomosis. Thirty-nine patients were identified. RESULTS: Twenty pAVFs were created from wrist ulnar vein access and 19 from radial vein access. The accessed veins were used for embolization of the brachial veins central to the newly created anastomosis. No pAVFs were lost by crossing adjacent to the anastomotic area to perform deep venous embolization at time of creation. There were no major complications, specifically bleeding, infection, pseudoaneurysm formation. Rates of minor complications consisted of two coil migrations to the right atrium requiring uneventful retrieval (5%). Follow-up ultrasound data showed no evidence of delayed complications. CONCLUSION: In this single center experience crossing alongside the anastomosis of a newly formed percutaneous fistula from an antegrade venous approach was safe with no risk of loss of the pAVF.

Polyethylene glycol additives reduce hemolysis in red blood cell suspensions exposed to mechanical stress.

Mechanical damage to blood cells is of considerable concern in the development and use of circulatory assist devices and other blood contacting systems. Furthermore, hemodilution with saline, dextran, and other plasma expanders applied during extracorporeal circulation and dialysis increases red blood cell (RBC) susceptibility to the high shear stresses associated with these procedures. In this paper, we present polyethylene glycol (PEG) as a potential erythrocyte protective agent against mechanically induced cellular trauma. Bovine RBCs were subjected to mechanical stress induced by rolling stainless steel shots through RBC suspensions for a constant exposure time. The suspensions were prepared at a hematocrit of 30% in various media: PEG (20,000 molecular weight), autologous bovine plasma, Dextran 40 solution, and phosphate buffered saline (PBS). RBC suspensions in Dextran 40 were prepared at a viscosity similar to the PEG suspensions. We found the hemolysis level of RBCs suspended in plasma and in PEG solutions to be several times lower (p < 0.001) than in the Dextran and PBS solutions. No statistically significant difference was found between the hemolysis that occurred in suspensions of RBCs in autologous plasma and in 2.0% PEG solutions. Even PEG concentration as low as 0.1% reduced hemolysis by more than 40% compared with PBS or the same concentration of Dextran in suspension medium. Our data demonstrate the efficacy of PEG molecules in reducing mechanical trauma to erythrocytes and suggest the potential for using PEG in assisted circulation, dialysis, and other procedures where RBCs are subjected to extensive mechanical stress.

In vitro evaluation of hemolysis and sublethal blood trauma in a novel subcutaneous vascular access system for hemodialysis.

Hemodialysis requires reliable frequent access to the patients' vasculature, with blood flow rates of > 300 ml/min. Currently in the U.S. market, there are three types of hemodialysis access systems: the native arteriovenous fistula, generally using 15G needles; the synthetic arteriovenous (AV) graft, also generally using 15G needles; and the percutaneous catheter. Some of the problems with current vascular access technologies include insufficient blood flow, blood trauma, thrombosis, infection, cardiac load, and venous stenosis. The LifeSite System (Vasca, Inc.) represents an alternative for vascular access, and consists of a subcutaneous valve and 12F cannula accessed by a standard 14G needle. The LifeSite valve is implanted in the upper torso with the cannula generally entering the right internal jugular vein. The purpose of this study was to compare the LifeSite System with two known vascular access systems: the 10F dialysis catheter (Tesio-Cath, MedComp) and the 15G A.V. Fistula Needle Set (JMS Co., Ltd.) with regard to blood damage produced by these devices in use. Mechanical hemolysis and sublethal blood trauma were evaluated by means of in vitro blood pumping through a circulating loop incorporating a hemodialysis vascular access system. Sublethal blood damage was examined by using a hemorheologic assay that included parameters such as erythrocyte mechanical fragility, plasma total protein and fibrinogen concentrations, and blood viscosity. The tests demonstrated that, at both studied flow rates of 300 ml/min and 450 ml/min, the LifeSite produced lower hemolysis and less sublethal damage to blood than either the Tesio-Cath catheter or the A.V. Fistula Needle Set.