Evaluation of Central Vein Sizes in Patients with Autogenous Hemodialysis Fistulas

Fracture and migration of implantable venous access port catheters: Cause analysis and management of 4 cases

This study aimed to investigate the causes and managements of the fractures and migrations of the implantable venous access port catheter (IVAPC). The fracture or migration of IVAPC occurred in 4 patients who were treated between May 2012 and January 2014 in Union Hospital, Wuhan, China. The port catheter leakage was found in 2 cases during drug infusion. Catheters that dislodged to the superior vena cava and right atrium were confirmed by port angiogram. The two dislodged catheters were successfully retrieved by interventional procedures. Catheter fracture occurred in two cases during port removal. One catheter was eventually removed from the subclavian vein through right clavicle osteotomy and subclavian venotomy, and the other removed by external jugular venotomy. Flushing the port in high pressure and injury of the totally implantable venous access port (TIVP) during implantation are usually responsible for catheter displacement. Interventional retrieval procedure can be used if the catheter dislodges to the vena cava and right atrium. Catheter fracture may occur during removal if clipping syndrome occurs or the catheter is sutured very tight during implantation.

Hemodialysis Catheter Tip Design: Observations on Fluid Flow and Recirculation

Purpose

To observe fluid flow patterns and measure recirculation rates of tunneled hemodialysis catheters using a mechanical model that simulates hemodialysis treatment.

Materials and methods

Nine tunneled hemodialysis catheters were evaluated using a mechanical model that simulated catheter conditions during a routine hemodialysis treatment. Objective and subjective determinants of catheter performance were measured and compared. Catheters were evaluated with blood lines connected in standard and reversed configurations using a fluid flow rate of 425 ml/min.

Results

With blood lines in standard configuration the Split Cath® was the only catheter to exhibit an atypical fluid flow pattern and significant tip movement. When the blood lines were reversed, three split-tip catheters had significant tip movement. The three step-tip catheters and two symmetric tip catheters had stable fluid flow patterns and no significant tip movement with blood lines connected in standard and reverse configurations. The nine catheters had no recirculation when connected in standard configuration. When the blood lines were reversed the percentage of recirculating fluid for symmetric tip, step-tip, and split-tip catheters was 0%, 15% to 20%, and 20% to 30%, respectively. The Equistream®, Palindrome™, and Symetrex catheters had no recirculation with blood lines connected in standard or reversed configurations.

Conclusions

Eight of the nine catheters evaluated in this study performed well with blood lines connected in standard configuration. When blood lines were reversed, symmetric tip and step-tip designs had more stable fluid flow patterns, less tip movement and lower recirculation rates when compared to split-tip designs.