Findings on intraprocedural non-contrast computed tomographic imaging following hepatic artery embolization are associated with development of contrast-induced nephropathy

BACKGROUND Contrast-induced nephropathy(CIN)is a reversible form of acute kidney injury that occurs within 48-72 h of exposure to intravascular contrast material.CIN is the third leading cause of hospital-acquired acute kidney injury and accounts for 12%of such cases.Risk factors for CIN development can be divided into patientand procedure-related.The former includes pre-existing chronic renal insufficiency and diabetes mellitus.The latter includes high contrast volume and repeated exposure over 72 h.The incidence of CIN is relatively low(up to 5%)in patients with intact renal function.However,in patients with known chronic renal insufficiency,the incidence can reach up to 27%.AIM To examine the association between renal enhancement pattern on non-contrast enhanced computed tomographic(CT)images obtained immediately following hepatic artery embolization with development of CIN.METHODS Retrospective review of all patients who underwent hepatic artery embolization between 01/2010 and 01/2011(n=162)was performed.Patients without intraprocedural CT imaging(n=51),combined embolization/ablation(n=6)and those with chronic kidney disease(n=21)were excluded.The study group comprised of 84 patients with 106 procedures.CIN was defined as 25%increase above baseline serum creatinine or absolute increase≥0.5 mg/dL within 72 h post-embolization.Post-embolization CT was reviewed for renal enhancement patterns and presence of renal artery calcifications.The association between noncontrast CT findings and CIN development was examined by Fisher’s Exact Test.RESULTS CIN occurred in 11/106(10.3%)procedures(Group A,n=10).The renal enhancement pattern in patients who did not experience CIN(Group B,n=74 with 95/106 procedures)was late excretory in 93/95(98%)and early excretory(EE)in 2/95(2%).However,in Group A,there was a significantly higher rate of EE pattern(6/11,55%)compared to late excretory pattern(5/11)(P<0.001).A significantly higher percentage of patients that developed CIN had renal artery calcifications(6/11 vs 20/95,55%vs 21%,P=0.02).CONCLUSION A hyperdense renal parenchyma relative to surrounding skeletal muscle(EE pattern)and presence of renal artery calcifications on immediate post-HAE noncontrast CT images in patients with low risk for CIN are independently associated with CIN development.

Estimation of successful capping with complete aspiration of bladder via nephroureterostomy tube

BACKGROUND Ureteral stent and nephroureterostomy tube(NUT)are treatments of ureteral obstruction.Ureteral stent provides better quality of life.Internalization of NUT is desired whenever possible.AIM To assess outcomes of capping trial among cancer patients with complete aspiration of retained contrast from bladder via NUT.METHODS Our Institutional Review Board approved retrospective review of all NUT placement,NUT exchange and conversion of nephrostomy catheter into NUT performed during June 2013 to June 2015(n=578).Cases were excluded due to lack of imaging of bladder(n=37),incomplete aspiration of bladder(n=324),no attempt at capping NUT(n=166),and patients with confounding factors interfering with results of capping trial including non-compliant bladder,bladder outlet obstruction and catheter malposition(n=14).Study group consisted of 37 procedures in 34 patients(male 19,female 15,age 2-83 years,average 58,median 61)most with cancer(prostate 8,endometrial 5,bladder 4,colorectal 4,breast 2,gastric 2,neuroblastoma 2,cervical 1,ovarian 1,renal 1,sarcoma 1,urothelial 1 and testicular 1)and one with Crohn’s disease.Medical records were reviewed to assess outcomes of capping trial.Exact 95%confidence intervals(95%CI)were calculated.RESULTS Among patients with complete aspiration of retained contrast,30(81%,95%CI:0.65-0.92)catheters were successfully capped(range 12-94 d,average 40,median 24.5)until planned conversion to internal stent(23),routine exchange(5),removal(1)or death unrelated to catheter(1).Seven capping trials(19%,95%CI:0.08-0.35)were unsuccessful(range 2-22 d,average 12,median 10)due to leakage(3),elevated creatinine(2),fever/hematuria(1)and nausea/vomiting(1).CONCLUSION Capping trial success among patients with complete aspiration of retained contrast/urine from bladder via NUT appears high.