Venous Window Needle Guide for deep vessels and difficult arteriovenous fistula cannulation.

The Venous Window Needle Guide (VWING™) has recently been proposed for patients with difficult arteriovenous fistula (AVF) access for hemodialysis due to deep vessels or other cannulation-related problems. This totally subcutaneous titanium device is sutured onto the upper wall of the matured fistula and may facilitate cannulation by the button-hole technique. We describe our initial experience with nine implants in six patients with a cumulative follow-up of 83 months, and make some experience-based technical suggestions for implant and surveillance radiological imaging. The indication for implantation was deep vessel, previous failure of cannulation or unsuitable site for direct cannulation. No infectious complications were observed during follow-up and proper blood flow was constantly achieved. Some difficulties were occasionally encountered with regard to cannulation; nonetheless, patient satisfaction was not significantly affected. VWING seems to be an interesting option in some patients provided that surgical implantation is carefully carried out and preventive measures against infections are strictly observed.

"Two is better than one": a composite graft made of two different vascular prostheses for urgent hemodialysis access in a troublesome case.

BACKGROUND: Multiple failed hemodialysis access and poor vascular anatomy can jeopardize an end-stage renal disease patient's survival, frequently leading to the urgent need for rapid and durable new vascular access. In these circumstances, the extensive use of central venous catheters (CVC) can led to serious complications, such as infection, thrombosis, and often vessel scarring with obstruction of the central veins. More recently, new self-sealing prosthetic grafts may be cannulated within a few days after implantation, avoiding the need for extensive CVC. However, similar to all synthetic arteriovenous grafts (AVG), the new grafts are prone to rapid and aggressive venous neointimal hyperplasia (VNH), which is responsible for outflow stenosis and access thrombosis. Endoluminal sutureless anastomosis has been demonstrated to have better hemodynamics at the venous outflow with a supposed reduction of VNH, thus potentially improving graft patency. METHODS: We report a case of a successful creation of a composite prosthetic access in a patient with severe comorbidities and nearly complete exhaustion of all vascular sites and with the need for immediate access for hemodialysis. Two relatively novel vascular expanded polytetrafluoroethylene prostheses were used jointly in this patient for a brachial-axillary AVG to allow early cannulation and with the aim of being less vulnerable to outflow stenosis. A multilayer self-sealing graft and a graft with a nitinol reinforced section, which permits endoluminal sutureless anastomosis, were sewed together to create a unique prosthesis with both features. RESULTS: The composite graft was cannulated 48 hr after implantation and continued to function well at 10 months of follow-up without signs of venous stenosis. CONCLUSIONS: This simple technique allows the creation of a customized composite graft with self-sealing properties and improved hemodynamics at the venous outflow.

Dealing with stuck hemodialysis catheter: state of the art and tips for the nephrologist.

The term stuck catheter refers to the condition in which a catheter is not removable from a central vein using standard techniques. Although it is a rare complication, in the last few years it has been reported ever more frequently in hemodialysis due to the widespread use of tunneled catheters. Poor knowledge of the correct procedures and limited experience and training of the specialist in facing this problem are the main reasons for catheter internalization. Stuck catheter is often diagnosed by the nephrologist, who should be competent enough to manage this clinical complication. Among the many options for removing a stuck catheter from the fibrin sleeve, an interventional radiology approach, mainly with endoluminal balloon dilatation, probably provides the best solution. Vascular surgery should be reserved to selected cases in which percutaneous techniques have failed. Nephrologists must play a central role in organizing the treatment of this complication with other specialists in order to avoid making mistakes that may preclude future positive results.