Effect of a Renal Protection Protocol on the Renal Function after Endovascular Aortic Aneurysm Repair

(Department of Cardiovascular Surgery, and Department of Radiology*, Kagawa Prefectural Central Hospital, Takamatsu, Japan, and Present address:Cardiovascular Surgery, Showa University**, Tokyo, Japan)

Atsushi Aoki** Takanori Suezawa Mitsuhisa Kotani
Shu Yamamoto Jun Sakurai*
Endovascular aortic aneurysm repair using stent graft(SG)for both thoracic and abdominal aortic aneurysms(SG therapy)rapidly became widespread in Japan because of its relatively low invasiveness. Pre- and postoperative contrast enhanced CT are mandatory in SG therapy and angiography is required during SG therapy. Therefore contrast induced nephropathy(CIN)might occur after SG therapy. In our hospital, a renal protection protocol(oral N-acetylcysteine, perioperative normal saline infusion and bicarbonate infusion during SG therapy)was introduced in June 2010. In this report, the effect of the renal protection protocol on renal function after SG therapy was evaluated. During May 2008 and March 2012, 229 patients underwent SG therapy in our hospital. Serum creatinine(CRTN)was higher than 1.5 mg/dl and estimated glomerular filtration rate(eGFR)was less than 50ml/min/1.73m2in 26 patients. In these 26 patients, the renal protection protocol was applied in 15 patients(group P)and group P was compared with the 11 patients without renal protection protocol(group N). Also the relationship between CIN occurrence and preoperative renal function was evaluated in 192 patients who did not receive the renal protection protocol. CIN was defined as more than 25% or 0.5mg/dl increase of CRTN based on the European Guidelines. As renal protection protocol, N-acetylcysteine(600mg)was given 4 times every 12 h. Normal saline infusion was started on the evening of the day before surgery at the rate of 50ml/h and was continued until 1h before surgery. Sodium bicarbonate solution(151mEq/l)was started 1 h before surgery at the rate of 180ml/h and the infusion rate was decreased to 60ml/h during surgery. After surgery, 1,000ml of normal saline was given at a rate of 60ml/h. In group N, CRTN increased 1 and 3 days after SG therapy and returned to baseline level 6 days after SG therapy. On the other hand, CRTN was lower than baseline after SG therapy in group P. At 3 days after SG therapy, the percent change of CRTN component with baseline level was significantly lower in group P(14.5±19.1% in group N, −3.7±15.8% in group P, p=0.014). CIN occurrence tended to be more in group N(45% in group N, 7% in group P, p=0.054). Among the 192 patients without the renal protection protocol, CIN occurred in 16 patients(29.1%)out of 55 patients with preoperative CRTN≧1.0mg/dl and eGFR≦50ml/min/1.73m2, however CIN occurred in only 1 patient(0.7%)among 137 patients with preoperative renal function out of this range(p<0.001). Renal protection protocol seemed to be effective to prevent CIN after SG therapy. Renal protection might be useful for patients with a CRTN≧1.0mg/dl and eGFR≦50ml/min/1.73m2.
  Jpn. J. Cardiovasc. Surg. 42:114-119(2013)

Keywords:endovascular surgery, stent graft, contrast media, kidney failure, renal function