Effect of contrast administration on the renal function of predialysis patients undergoing fistuloplasty

The aim of this study was to investigate if administration of iodinated contrast during endovascular interventions in arteriovenous fistula (AVF) in patients not requiring dialysis (predialysis patients) (1) negatively affects their renal function and (2) if oral hydration has a protective effect.

All pre-dialysis patients who underwent endovascular interventions in AVF between August 2010 and April 2019 were included in the study. During the procedures, 35 to 50 mL of Iodixanol were administered. A pre-hydration protocol was introduced in March 2015. Data were grouped before and after this date. The difference between pre- and post-contrast estimated glomerular filtration rate (eGFR) and the difference between the eGFR of hydrated and non-hydrated groups were calculated.

Eighty-four patients who underwent 151 procedures were included in the study. In 60.3% of procedures, a mean decrease of 1.35 mL/min/1.73 m² in eGFR was noted (95% confidence interval [CI], 1.02-1.69 mL/min/1.73 m²), whereas in 35.1% of procedures, there was a mean increase of 1.06 mL/min/1.73 m² (95% CI, 0.84-1.28 mL/min/1.73 m²). The mean difference between pre- and post-procedure eGFR was -0.44 mL/min/1.73 m² (95% CI, -0.72 to -0.16 mL/min/1.73 m²; P = .002). Oral hydration was associated with a smaller mean change in eGFR of -0.32 mL/min/1.73 m² (95% CI, -0.62 to -0.03 mL/min/1.73 m²) compared with the non-hydrated group, with mean change of -0.47 mL/min/1.73 m² (95% CI, -0.91 to -0.03 mL/min/1.73 m²), but this was not statistically significant (P = .586).

This study demonstrates that administration of up to 50 mL of iodinated contrast for endovascular interventions in AVF in predialysis patients has minimal adverse effect on the eGFR with questionable clinical significance. In addition, oral hydration before and after the procedure has only a mild protective effect against a decrease in eGFR.