Background We report the incidence and risk factors for contrast-induced nephropathy (CIN) after the use of high dose radio contrast media (RCM), defined as 250 ml or greater, during neuroendovascular procedures.

Materials and Methods An institutional review board-approved retrospective chart review was performed on all patients that received a RCM dose of 250 ml (Omnipaque 240 and/or Omnipaque 300) or greater while undergoing a neuroendovascular procedure between January 2011 and February 2013. Patients with an estimated GFR ≤ 30 or a documented history of chronic kidney disease (CKD) were excluded.

Age, sex, and weight were recorded. Premorbid medical conditions of hypertension, hyperlipidaemia, coronary artery disease, diabetes mellitus and chronic renal insufficiency were also documented.

We reviewed baseline kidney function and post-procedure serum creatinine levels at 24 and 48 hours. We estimated pre-procedure glomerular filtrate rate (GFR) and creatinine clearance (CrCl) using the Cockcroft-Gault formula. We determined the contrast ratio (V/CrCl) by dividing the administered RCM volume by the CrCl. We calculated the maximum contrast dose (MCD) using the formula proposed by Cigarroa and colleagues¹: MCD (ml) = 5 × body weight [kg] (maximum 300 ml) divided by serum creatinine (mg/dl). CIN was defined as an increase in serum creatinine 50% above the baseline or an absolute increase of 0.3 mg/dl at either 24 or 48 hours post procedure.

Results Between January 2011 and February 2013, 1941 diagnostic and interventional neuroendovascular procedures were performed at our institution. A total of 89 patients received a RCM dose of 250 ml or greater. Ten patients were excluded, six due to lack of post-procedure serum creatinine data at both 24 and 48 hours and four due to GFR ≤ 30 or history of CKD. Post-procedure serum creatinine data was available in 79 patients at 24 hours and in 67 patients at 48 hours.

Thirty-six patients (46%) received a RCM dose between 250–299cc, 29 (37%) between300–399cc, 9 (11%) between 400–499cc, and 5 (6%) greater than 500cc. The average creatinine change at 24 hours was -3.6%, -4.1%, +5.9%, -9.1%, respectively. The average creatinine change at 48 hours was -23.8%, -10.8%, -23.5%, and -13.6% respectively.

There were 4 (5%) cases of CIN, three at 24 hours and one at 48 hours. On average, patients with CIN had a serum creatinine increase of 0.30 mg/dl (+32.5%) at 24 hours and 0.51 mg/dl (+45.4%) at 48 hours. There was a non-statistically significant trend towards higher rates of premorbid history of diabetes and higher baseline creatinine levels. As the RCM dose increased, so did the incidence of CIN: 2.8% for250–299cc, 6.9% for300–399cc, and 11.1%400–499cc. However, no patients with a RCM dose greater than 500cc developed CIN. Furthermore, only one of the seventeen patients that exceeded the MCD developed CIN. A V/CrCl ratio ≥2.88 was associated with a higher incidence of CIN, however the average V/CrCl ratio of those that did not develop CIN was 3.2.

Conclusions Risk of developing CIN is low in patients undergoing neuroendovascular procedures using RCM doses of 250 ml or greater.

Disclosures V. Prasad: None. G. Jindal: None. D. Gandhi: None.