Trends in followup imaging after adult pyeloplasty

Abstract

Purpose: Although success rates are reported to be high, radiographic followup after pyeloplasty to correct ureteropelvic junction obstruction varies in intensity and modality. We characterized postoperative care after pyeloplasty to identify imaging trends.

Materials and methods: Using the MarketScan® database we identified patients 17 to 65 years old treated with pyeloplasty from 2007 to 2010. Followup imaging was classified as functional (diuretic renogram or excretory urogram) and nonfunctional (ultrasound, computerized tomography or magnetic resonance imaging). The postoperative period was divided into intervals of less than 6, 6 to 12, 12 to 24, 24 to 36 and greater than 36 months. We excluded from study patients with less than 24 months of postoperative enrollment in MarketScan. Multivariate logistic regression was used to determine associations between demographic variables and imaging utilization patterns.

Results: We identified 742 patients with a mean ± SD followup of 36.8 ± 3.7 months, of whom 65% underwent minimally invasive pyeloplasty. Of the patients 12% underwent no postoperative imaging. Within the first 6 months 554 patients (75%) underwent at least 1 imaging study and within the first 12 months 82% underwent at least 1 imaging study, which was most commonly functional. After 12 months 54% of patients underwent any imaging, which was most commonly nonfunctional. At least annual imaging was significantly associated with older age, female gender and longer hospital stay. Secondary procedures were required in 62 patients (8%).

Conclusions: After pyeloplasty in adulthood most patients undergo a functional imaging study within 6 months. However, after 1 year only half of patients undergo followup imaging. Variability and insufficient radiological followup may bias the belief of pyeloplasty success.

Keywords: diagnostic imaging; follow-up studies; hydronephrosis; kidney; ureteral obstruction.