3:36 PM Abstract No. 65 Ureteral stent placement prior to percutaneous nephrostomy is associated with decreased radiation dose and fluoroscopy time

Abstract

To identify patient and technical factors that contribute to increased radiation dose and fluoroscopy time during percutaneous nephrostomy placement. Patients who underwent percutaneous nephrostomy (PCN) placement from January 2012 to June 2017 were identified. Degree of hydronephrosis was graded by consensus as grade 0 (one), 1 (mild), 2 (moderate), or 3 (severe) according to Society of Fetal Ultrasound criteria. Radiation dose and fluoroscopy time per PCN were recorded. Bilateral PCNs with two equal grades were considered two unique PCNs which equally shared radiation dose; bilateral PCNs with two different grades were excluded. Additional data, including presence of ureteral stent, laterality, simultaneous bilateral placement, and body mass index, were also collected. Statistical analysis was performed using Spearman rank correlation to assess association of hydronephrosis grade with dose and time, and ANOVA and ANCOVA tests compared dose and time without and with adjustment for BMI. Mann-Whitney test was performed to compare dose and time for procedures with and without stent. A total of 244 PCNs were performed on 185 patients (54.5% male, mean age 67.3 years). Hydronephrosis grade negatively correlated with both radiation dose and fluoroscopy time independent of BMI (p<0.001). The presence of a ureteral stent was associated with a large radiation exposure reduction across all grades of hydronephrosis, decreasing overall dose by 36.7% and time by 18.4%. The greatest reductions in dose and time in the presence of a stent were observed in the Grade 0 and 1 PCNs, with decreases of 54.8% for dose and 45.5% for time. Presence of stent greatly reduces radiation dose and fluoroscopy time during PCN, particularly in obese patients with mild or no hydronephrosis who may be subject to very high radiation exposure. We propose that such measures as preprocedural cystoscopic ureteral stent placement if feasible or, by extension, intravenous pyelogram can provide the interventionalist with a target for percutaneous access, thereby reducing radiation exposure to both patient and practitioner.