An analysis of the factors influencing radiation dose and fluoroscopic time during renal artery stent placement

Purpose: To determine the factors that affect mean absorbed dose and fluoroscopic times during renal artery stent placement. Materials and Methods: After institutional review board approval, the HI-IQ database was queried for patients undergoing renal artery stent placement only from January 2007 to June 2010. Procedures that were performed as part of other procedures such as iliac artery stents were excluded. The HI-IQ data included fluoroscopy time (f) and radiation dose (mGy). Demographic, medical history, procedural details, and advanced preprocedural renal artery stent imaging were obtained. Variables (number of stents, average body mass index , number of stents placed per year and number of years service of an interventional physician, pre-procedural imaging, and use of embolic protection device) were analyzed using a t test after log transformation and testing for variance with an F test. Results: A total of 134 patients (75 males, 70.6 ± 10.5 years old) underwent the placement of 177 renal artery stents (unilateral [n =95], average stent per patient =1.3). Mean fluoroscopy time was 15.6 minutes and mean absorbed dose to the patient was 1729 mGy. The average fluoroscopic time and absorbed dose was significantly higher with bilateral stent placement compared to unilateral placement (13.8 vs 19.7 minutes, P =.002; 1803 vs 2380 mGy, P =.03). The average fluoroscopic time was significantly higher in patients undergoing abdominal aortogram prior to renal artery selection and stent placement. Conclusion: The placement of more than 1 stent with an abdominal angiogram prior to renal artery stent placement results in increased fluoroscopic time and mean absorbed dose.