Hemodialysis catheter locking solutions and the prevention of catheter dysfunction: a meta-analysis

Tunneled dialysis catheters (TDCs) continue to be utilized at an alarming rate despite having a higher rate of complications when compared to fistulas and grafts. One of the primary complications of TDCs involves catheter dysfunction resulting in reduced blood flow and poor dialysis adequacy, often requiring catheter removal in addition to thrombolytic therapy. Our objective was to compare the use of locking solutions containing heparin versus all other locking solutions for primary prevention of TDC dysfunction.

We searched Medline for English language literature from 1980 through December 2013, along with national conference proceedings and reference lists of all included publications to identify relevant studies. Inclusion criteria were a measure of incidence of catheter dysfunction, catheter exchange or use of thrombolytic therapy. Studies were excluded if they were not in English or if they included pediatric patients. Random effects models were used to derive the pooled risk ratios.

Thirteen studies with a total of 1,883 subjects met the inclusion criteria. There was no significant difference in catheter patency in those receiving heparin versus those treated with other lock solutions (incidence rate ratio [IRR] 0.99; 95% confidence interval [CI] 0.66-1.48, p = 0.96). Catheter patency did not differ between treatments in experimental studies (n = 10; IRR = 0.89; 95% CI: 0.56-1.39, p = 0.60) or observational design (n = 3; IRR = 1.64; 95% CI 0.40-6.85, p = 0.50). Significant heterogeneity was detected across studies (I2 = 84.4%, p<0.001).

Our results suggest that there is no substantial difference between heparin lock solutions versus all other types of catheter lock solutions for catheter dysfunction. Whether there are significant benefits of citrate or other novel lock solutions requires further robust studies. These findings have significant implications for future design of clinical trials in TDCs and the delivery of dialysis-related services.