Improved split renal function after percutaneous nephrostomy in young adults with severe hydronephrosis due to ureteropelvic junction obstruction.

PURPOSE: We evaluated percutaneous nephrostomy for adult kidneys with severe hydronephrosis due to ureteropelvic junction obstruction and less than 10% split renal function.

MATERIALS AND METHODS: In this retrospective analysis we included patients who underwent percutaneous nephrostomy for unilateral ureteropelvic junction obstruction of the kidneys with hydronephrosis and less than 10% split renal function at our hospital between May 2009 and January 2012. Adults (age 18 years or greater) were divided into those 35 years or younger (young adults) and older than 35 years (older adults). The percutaneous nephrostomy remained in situ a mean ± SD of 6.62 ± 2.55 weeks and patients underwent repeat renography before pyeloplasty. When there was no significant improvement in split renal function (10% or greater) and drainage (greater than 400 ml per day), nephrectomy was performed. Otherwise pyeloplasty was performed. Patients were followed by renography, ultrasound and contrast computerized tomography at 3 and 6 months, at 1 year and annually thereafter.

RESULTS: Of 53 patients 30 (56.6%) showed improvement after percutaneous nephrostomy drainage and urine output greater than 400 ml per day with percutaneous nephrostomy. Pyeloplasty was then performed. Of 29 young adults 24 (82.8%) showed improved split renal function vs 6 of 24 older adults (25%). Nephrectomy of the other 23 kidneys was performed. At a mean followup of 19.27 ± 7.82 months (range 12 to 36), no patient showed hypertension or urinary tract infection.

CONCLUSIONS: Split renal function detected by renography may not accurately predict recovered, poorly functioning kidneys, especially in young adults. First observing the recoverability of hydronephrotic kidneys by percutaneous nephrostomy drainage and then preserving select kidneys may be an effective method to manage poorly functioning kidneys due to ureteropelvic junction obstruction.