The Journal of Vascular Access

A prospective observational study was performed to determine the duration of use of the Ash Split Cath placed as primary or bridge access in ESRD patients; 164 ESRD patients received a Split Cath in the IJ location, with transcutaneous placement guided by ultrasound. Mean follow-up time was 19.3 months (maximum up to 48 months). During the follow-up, there were 36 catheter failures resulting in removal, 53% due to infection and the others due to outflow failure or break (leak) of the catheter. By Kaplan-Maier analysis 82% of placed catheters were functional at 12 months and half-life of catheter duration was 26 months. Blood flow rates during dialysis were not distinguishable between IJ catheter patients and those with functioning grafts or fistulas. Function, safety and duration of use of the Split Cath in the IJ location all compare favorably to AV grafts.

Background/Aims: The aim of the study was to evaluate the efficacy of stenting for the treatment of central arm vein obstructions in hemodialysis patients in order to maintain hemodialysis from the affected side. Methods: Fifteen self-expanding (8) and balloon expandable (7) stainless steel stents were implanted in 10 hemodialysis patients for the treatment of symptomatic central arm vein obstructions. Thirteen lesions were treated: 6 subclavian, 4 innominate and 3 restenoses. Results: Stent deployment was successful in all cases leading to resolution of symptoms by correcting the underlying cause of venous hypertension. Follow-up from 3 months to 4 years revealed four deaths from unrelated causes, three restenoses at 1, 3, 4 months and one occlusion at 6 months respectively for a cumulative primary one-year and two-year patency rate of 70%. Conclusion: Stenting of subclavian and innominate venous stenoses and occlusions effectively corrected the underlying lesions responsible for disturbed hemodynamics and, in most cases, prolonged available hemodialysis access from the affected side.

Femoral catheterization is fast and simple and associated with a low risk of complications. Those which occur can usually be managed easily. Femoral catheters are usually kept in place for a short period of a few days. We, instead, used femoral catheters (FC) as a temporary vascular access for a longer period of time (until the permanent vascular access matured) in inpatients and in outpatients on regular ambulatory hemodialysis who had a problem with their permanent access. We analyzed 59 patients with end-stage renal disease treated with hemodialysis (HD), divided into two groups. Of the group that started with hemodialysis (group I), only 16 patients were hospitalized during the maturation of native arterio-venous fistula (AVF). Duration time of the catheters was 15–47 days (average 32 days). The second group (group II) comprised 43 patients going on regular ambulatory hemodialysis who were discharged from hospital with femoral catheters. Duration time of catheters in this group was 13–183 days (average 44.2 days). Catheters were removed when AVF matured, or if a significant complication occured. We took blood culture from peripheral vein (BCP) and from catheter (BCC) on removal of the catheter, or when we suspected infection. Catheter tips (CT) were also sent for microbiological analysis. We monitored the clinical signs of infection. We compared microbiological results of BCP, BCC and CT from the two groups using chi-square test and we did not find any significant difference among the three types of findings (p<0.05). The FC was removed from one patient only from group II because of suspicion of catheter-related infection. Two pts were treated with antibiotics (AB) systemically and locally (AB was “locked” in the catheter) because of febricity. When the catheters were removed the microbiological findings were sterile. We concluded that FC can be used without any problem for a longer period of time for ambulatory HD, with the provision of permanent care from a team specially trained for vascular access.

The tip of a central vein catheter for hemodialysis should be located in the upper right atrium for the best performance. Hemodialysis catheters do have internal diameter unadjusted to the catheter length; however, the longer the catheter the slower the flow at the same pressure difference. On the other hand, the catheter diameter cannot be so large as to fill the vein too tightly as it predisposes to the damage of the vein wall, thrombosis and stenosis. Therefore, the catheter length and diameter should be appropriate for the patient. For this purpose, the exact dimensions of the venous system in vivo should be known. In this study we correlated the anthropometric measurements and the dimensions of the large upper body veins in 31 adult volunteers.

After deep inspiration, magnetic resonance imaging of the chest was performed in three planes; the positions of specific points in the three-dimensional coordinate system were measured, and the distance to adjacent points was calculated according to the analytic geometry formula. The total length from the catheter entry point to the right atrium was the sum of distances between the adjacent points. The lengths of the veins were correlated with the body anthropometric measurements (height, weight, body surface area, biacromion span, and height plus biacromion span).

The best overall correlations of the lengths and diameters of the large upper body veins are with the body surface area. A table is included to guide the selection of the total catheter length and diameter in relation to the body surface area and insertion site.

Tunneled catheters serve as interim access during maturation of a graft or fistula, or as a permanent vascular access in those patients who have exhausted their traditional access sites. However, bacteremia rates are high in patients with chronic catheters and indiscriminate removal of catheters during bacteremia increases morbidity and costs. A method to identify whether a catheter was colonized with the offending bacteria, without requiring catheter removal is desirable.

We compared endoluminal brushing and heparin aspiration, to detect catheter colonization, in 24 asymptomatic patients undergoing elective tunneled hemodialysis catheter removal. The incidence of catheter colonization was highly correlated with catheter duration of ≥ 30 days (p=0.03). Staphylococcus epidermidis represented 68% of the organisms isolated. No other organism accounted for more than 7% of the total. Fifteen (62.5%) of the 24 catheters had positive cultures. Eleven of the catheters were positive by culture of heparin aspirate and eight were positive by endoluminal brushing. Only four of the catheters were positive by both methods. The arterial lumen was more likely to have positive cultures than the venous lumen using either method.

In this prospective investigation of tunneled hemodialysis catheters in asymptomatic patients we have demonstrated that a heparin aspirate sample is more likely to detect catheter colonization than a sample obtained using an endoluminal brush. Furthermore, 75% of catheters present for more than 30 days were colonized. Further study is needed to determine if the heparin aspirate method could be used in patients with bacteremia to accurately identify catheters that need removal.