Author: Rayan Abboud, MS, Medical Student, Wake Forest School of Medicine

Editor: Justin Foster, MD, PGY-4 Rochester Regional Health, Rochester, NY

Introduction

In patients in need of intermediate or long-term hemodialysis, tunneled hemodialysis catheters [1] are initially used until arteriovenous access (e.g. fistula) can be established. Like other central venous access catheters, hemodialysis catheters are typically inserted in the internal jugular vein (IJ) or the subclavian vein [2]. In contrast, these catheters have a larger bore to achieve higher flow rates for blood exchange. Long-term complications of hemodialysis catheters include central vein thrombosis or stenosis, inadequate flow rates, catheter dysfunction, and infection. However, optimal insertion techniques, catheter tip location, and access site that minimize complications of hemodialysis catheters are not agreed upon in the literature.2

In the September 2013 issue of JVIR, researchers at the Duke University Medical Center retrospectively investigated the impact of access laterality (right-sided vs. left-sided) and final catheter tip position on tunneled IJ hemodialysis catheter dysfunction and infection rates.

Study Population and Protocol:

In a retrospective review, hemodialysis catheter placements between January 2008 and December 2009 of 409 patients (male = 234; mean age, range = 54.9, 19-91 y) with 532 unique catheter insertions were analyzed. Inclusion criteria included patients with Decathlon catheters and IJ catheter insertions. Catheter exchanges were excluded from the cohort. Patient data was obtained until date of removal, patient death, or October 2011. Catheters were placed by interventional radiologists, attendings, or fellows under the supervision of attendings. Operator preference determined the laterality of insertion (right = 398 and left = 134), and catheter tip position was at either the cavoatrial junction or the mid-right atrium.

Data Collection and Statistics:

Patient demographics and access site laterality were collected from a procedural database. Two radiologists determined the final location of catheter tip from intraprocedural fluoroscopic images. Catheter tip location was categorized relative to the intersection of the right mediastinal border and right heart border. Catheter tips were located either 1) above the intersection (superior vena cava), 2) within one vertebral body below the intersection (pericavoatrial region), or 3) greater than one vertebral body below the intersection (mid- to deep-right atrium). Hemodialysis catheter dysfunction was defined as catheter exchange due to inadequate flow rate. Catheter infection was defined as catheter removal secondary to infection, with common symptoms including erythema, tenderness, or drainage.  

Demographic data were for right and left-sided catheter placement were compared using chi-squared analysis for categorical variables (sex, HIV status, diabetes, steroid therapy, chemotherapy, malignancy, and hypercoagulability) and Student t-test for continuous variables (age and BMI). Hemodialysis catheter dysfunction rates, as defined above, were also compared between left and right catheter placement groups. Additionally, Kaplan-Meier analysis, a type of survival analysis, was used to measure the fraction of dysfunction-free hemodialysis catheters for a given time from the date of insertion. In other words, it measures the time-to-failure of hemodialysis catheters. To compare whether right or left-sided catheters “survived” longer, the log-rank test assessed if there was a significant difference in dysfunction-free days between the two groups. Kaplan-Meier and log rank tests were repeated on catheter tip position groups (SVC, pericavoatrial, mid/deep right atrium).

Results and Outcomes:

No differences were seen in demographic data between right and left-sided catheter insertions. The overall dysfunction/infection rate for 532 catheters was 0.35 episodes per 100 catheter-days, where 66 catheters and 213 catheters were exchanged or removed for dysfunction and infection, respectively. Right IJ access (74.8%) was preferred over left IJ access (25.2%). Significantly higher rates of infection or dysfunction were seen in left compared to right IJ catheters (0.45 vs 0.31, p = .003).

Catheter tip positions varied between groups, such that 7% terminated in the SVC, 32% at the pericavoatrial junction and 61% in the mid- to deep- right atrium. Between the three separate groups, no difference was seen in catheter dysfunction or infection (p = .197 and p = .054, respectively). However, catheters placed in the SVC or pericavoartial junction yielded a significantly higher rate of dysfunction or infection compared with the right atrial group alone (p = .28). Lastly, researchers evaluated the rates of dysfunction and infection for each catheter tip position based on laterality. Notably, left sided catheters with tips terminating in the SVC or pericavoartrial junction had higher rates of dysfunction or infection compared with the right atrial insertion group (p = .006). This observation was not significant in right-sided catheters (p = .36).

Conclusions

While institutional guidelines differ in the optimal position of catheter tips, none are based on the rates of catheter infections or dysfunction.2 Importantly, these outcomes are significant contributors to dialysis costs and significant sources of morbidity in the indicated population. Thus, in cases were right-sided catheters are contraindicated, the results suggest that optimal catheter tip location is in the mid- to deep-right atrium. Additionally, the lower infection rate observed in right-sided catheters is in agreement with prior studies. Therefore, it is suggested that interventionalists take these factors into consideration,, and position catheter tips in the right atrium, especially in left IJ approaches. Limitations of the study include its retrospective nature, which specifically, prevented a robust definition of infection, as cultures were not routinely obtained, and relatively few catheters tips terminated in the SVC on left-sided approaches, which limited statistical analysis.

References

1. Fan PY, Schwab SJ. Vascular access: concepts for the 1990s. J Am Soc Nephrol. 1992;3(1):1-11.

2. Engstrom BI, Horvath JJ, Stewart JK, et al. Tunneled Internal Jugular Hemodialysis Catheters: Impact of Laterality and Tip Position on Catheter Dysfunction and Infection Rates. Journal of Vascular and Interventional Radiology. 2013;24(9):1295-1302. doi:10.1016/j.jvir.2013.05.035