Serum creatinine trajectory after drainage of kidneys with bilateral malignant ureteral obstruction: a prospective non-randomized comparative study

Background Serum creatinine trajectory (SCr-Tr) is a neglected prognostic tool for chronic and acute kidney injury.

We aimed to assess the predictors of SCr-Tr during the time-to-nadir and serum creatinine (SCr) normalization rate after drainage, using percutaneous nephrostomy in patients with bilateral malignant ureteral obstruction.

Methods A prospective non-randomized study was performed on SCr-Tr in patients with bilateral malignant ureteral obstruction from August 2019 to March 2022.

The primary outcome was SCr-Tr during the time-to-nadir.

Results This study included 102 patients with a mean age ± SD of 59.6 ± 14.7 years.

SCr-Tr was non-linear with a mean ± SD (range) of 0.5 ± 0.4 (0.03–2.3) mg/dl/day.

Multivariate analyses revealed that female gender ( p  = 0.016), body mass index (BMI; p  = 0.005), and SCr at presentation ( p  < 0.001) were predictors of rapid SCr-Tr during the time-to-nadir.

However, age ( p  = 0.008) and low urine output at presentation ( p  = 0.015) were associated with a lower SCr-Tr.

In contrast, laterality of drainage ( p  = 0.544) and mean parenchymal thickness ( p  = 0.066) were not associated with mean SCr-Tr.

Also, only the mean parenchymal thickness ( p  = 0.002) was a predictor of rapid SCr-Tr at ≥ 0.5 mg/dl/day.

However, low BMI ( p  = 0.023) was associated with a high SCr normalization rate, while unilateral drainage ( p  = 0.045) was associated with a lower rate.

Conclusions Female gender, low BMI, and SCr at presentation were predictors of rapid SCr-Tr during the time-to-nadir.

Bilateral drainage was an independent predictor of SCr normalization rate, but not of rapid SCr-Tr.

The mean parenchymal thickness was the only independent predictor for rapid SCr-Tr at ≥ 0.5 mg/dl/day.