Predicting factors for improvement of serum creatinine after percutaneous nephrostomy in adults with bilateral hydronephrosis associated with malignancy

Objective: Improvement of renal function in obstructive uropathy is a main goal of urinary diversion. In cases of failed internal diversion, percutaneous nephros-tomy (PCN) is used to divert urine from the obstructed kidney. PCN also affect on quality of life, particularly having both sides. The objective of this study was to identify a predicting factor associated with improvement of renal function after bilateral PCNs and to avoid performing bilateral PCNs. Materials and Methods: Data of all patients with bilateral hydronephrosis asso-ciated with malignancy who were performed bilateral PCNs in Siriraj Hospital between December 2011 and December 2016 were reviewed and collected. Success with PCN was defined as a serum creatinine less than 2 mg/dl or decreased more than 95% of initial serum creatinine. Results: A total of 240 patients met the criteria. Mean age was 64.6 ± 14.9 years old. Most common organ of malignancy was cervix. Mean initial serum creatinine (iCr) and nadir serum creatinine (nCr) were 7.7 and 1.9 mg/dl, respectively. On multivariate analysis, no significant predicting factors were demonstrated but only iCr tended to have a statistically significant (p = 0.058). From receiver operating characteristics analysis, at cut-off value of iCr 5 mg/dl could demonstrate signifi-cant difference between success and failure (p = 0.027). Sensitivity and specificity were 72.4% and 44.0%, respectively. Conclusion: Only the iCr was more likely to be a predicting factor. At cut-off value of iCr 5 mg/dl, if a patient presented with iCr more than 5 mg/dl and unilateral PCN at dominant side did not improve serum creatinine, performing contralateral PCN might not help.