Safety of Low Volume Iodinated Contrast Administration for Arteriovenous Fistula Intervention in Chronic Kidney Disease Stage 4 or 5 Utilizing a Bicarbonate Prophylaxis Strategy

Initiation of hemodialysis at one month following fistulogram in patients with advanced kidney disease

OBJECTIVE

Previous studies have demonstrated that low contrast volume used in access-related interventions had limited effects on the progression of chronic kidney disease (CKD) after fistulography, but studies are limited and heterogeneous. We sought to evaluate the rate of and factors associated with progression to dialysis (HD) within 1 month after fistulography for patients with advanced CKD.

METHODS

A single-institution retrospective cohort analysis of patients with CKD stage IV and V, not yet on HD, undergoing fistulography from 1 January 2014 to 31 December 2018 was performed. The primary outcome was progression to HD within 1 month. Additional variables and the association with the primary outcome such as medical comorbidities, contrast type or volume were assessed.

RESULTS

A total of 34 patients underwent 41 fistulograms prior to HD initiation. Progression to HD within 1 month of fistulogram occurred in seven patients (all CKD V). The mean time between fistulogram and HD was 271 days for 31 of 34 patients who ultimately progressed to HD. Those with CKD IV began HD in 549 days on average, while those with CKD V began HD in 190 days on average. Three patients had not initiated HD at a mean of 539 days of follow-up. The only factors associated with progression to HD within 1 month included use of isovue (p = .005) and elevated contrast volume, with a mean of 40 mL (p = .027).

CONCLUSION

Although none of the patients with CKD IV required HD within 1 month after fistulogram, the use of larger iodinated contrast volume was associated with progression to HD within 1 month of fistulography for patients with CKD V. Further studies should investigate the safety of iodinated and alternative (e.g., carbon dioxide) contrast media in fistulography or duplex-based HD access procedures for CKD patients, especially CKD V, not yet on HD.

Randomised controlled trial to evaluate the effect of contrast material dilution on renal function in patients after endovascular aortic repair: rationale and design for the CULTURE trial

INTRODUCTION

Postoperative renal function decline is a major concern for thoracic endovascular aortic repair (TEVAR) and endovascular abdominal aortic repair (EVAR). Diluting contrast medium in the power injector may be helpful in reducing the risk of contrast-induced nephropathy, but it can also blur fluoroscopic vision during surgery. The quality of the current evidence is very low; thus, this study is designed to investigate the effect of contrast dilution in the power injector on renal function changes in patients after endovascular aortic repair.

METHOD AND ANALYSIS

The study is a prospective, single-blind, parallel, non-inferiority, randomised controlled trial with two independent cohorts: Cohort TEVAR and EVAR. Individuals will enter the appropriate cohort based on clinical interviews if they meet the eligibility criteria. Participants in Cohort TEVAR and EVAR will be randomly allocated to the intervention group (diluting contrast medium to 50% in the power injector) and control group (pure contrast medium in the power injector) separately in a 1:1 ratio. The primary study points consist of the proportion of patients who develop acute kidney injury within 48 hours after TEAVR or EVAR (first stage) and freedom of major adverse kidney events at 12 months after TEAVR or EVAR (second stage). The safety endpoint is freedom of all types of endoleaks at 30 days after TEVAR or EVAR. Follow-up will be conducted at 30 days and 12 months after intervention.

ETHICS AND DISSEMINATION

The trial was approved by the Ethics Committee on Biomedical Research, West China Hospital of Sichuan University (approval number: 20201290). The results of the study will be disseminated through publications in peer-reviewed journals and presentations at academic conferences.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2100042555).

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

OBJECTIVE

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.

METHODS

All pre-dialysis patients who underwent endovascular interventions in AVF between August 2010 and April 2019 were included in the study. During the procedures, 35-50mL 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.

RESULTS

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%CI 1.02, 1.69), while in 35.1% there was a mean increase of 1.06 mL/min/1.73 m² (95%CI 0.84, 1.28). The mean difference between pre- and post-procedure eGFR was -0.44 mL/min/1.73 m² (95% CI -0.72, -0.16) (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, -0.03) compared to the non-hydrated group with mean change of -0.47 mL/min/1.73 m² (95% CI -0.91, -0.03), but this was not statistically significant (p=.586).

CONCLUSIONS

This study demonstrates that administration of up to 50mL 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.

Clinical use of biomarkers for toxicant-induced acute kidney injury

Toxicant-induced acute kidney injury (ToxAKI) causes substantial morbidity and retards drug development. ToxAKI is relatively underexplored compared with ischemia–reperfusion injury in clinical biomarker studies. We highlight the rationale for novel AKI biomarkers in management of ToxAKI, and review the contemporary evidence supporting their clinical use. Directly-acting nephrotoxins, such as cisplatin, aminoglycosides, vancomycin and radiocontrast, remain widely used and highlight how novel biomarkers can either improve the detection of changes in glomerular filtration rate or directly signal cellular injury and structural damage. Serum cystatin C has already improved clinical risk prediction and drug dosing although its clinical use for early diagnosis awaits validation. The use of novel functional and structural biomarkers to stage ToxAKI and aid prognosis requires robust validation and better understanding of the relationship between biomarkers, morbidity and mortality. Biomarkers that illustrate the probable mechanisms and phase of ToxAKI may guide mechanism-specific diagnosis and therapy.

Contrast alternatives for iodinated contrast allergy and renal dysfunction: options and limitations

Diagnostic angiography and vascular interventions make routine use of iodinated contrast material (ICM). Patients with renal disease or contrast allergy pose limitations on the use of ICM. In such cases, alternative contrast media may be used to carry out the procedure. Current alternatives include carbon dioxide, gadolinium, and dilute ICM. Each of these alternatives has its own unique features and limitations. In the present review article, the current alternatives to ICM are explored, with a focus on the applications and restrictions of each.

Prevention and management of contrast-induced acute kidney injury

OPINION STATEMENT

Contrast-induced acute kidney injury (AKI) is an important complication associated with coronary angiography, percutaneous coronary intervention, and computed tomography studies. The increasing utilization of contrast agents for imaging makes the importance of this complication even greater. Patients can be risk stratified for the risk of contrast-induced AKI by several clinical factors including hypotension, renal function, age, advanced heart failure, anemia, and diabetes mellitus. Contrast volume is also an important and modifiable risk factor for AKI. For the prevention of contrast-induced AKI, multiple approaches have been tried. The most effective prevention strategy is hydration. Normal saline has been the standard, but other options such as sodium bicarbonate may be a reasonable alternative. Further studies will be required to clarify the best preventive strategies.