title: Evaluation of Renal Histopathological Changes, as a Predictor of Recoverability of Renal Function Following Pyeloplasty for Ureteropelvic Junction Obstruction.
abstract: BACKGROUND
  Pyeloplasty is a widely accepted treatment for ureteropelvic junction obstruction (UPJO). However, the renal function recoverability after pyeloplasty is still a matter of debate. Different parameters have been used to predict renal functional recoverability after corrective surgery, with conflicting results.
  
  
  OBJECTIVE
  In this study, renal biopsy was carried on a series of cases of UPJO, during pyeloplasty, to study the extent of histological alterations in renal parenchyma, as a result of obstruction, and its predictive value in renal function recoverability after pyeloplasty.
  
  
  METHODS
  We retrospectively analyzed the renal biopsy obtained during pyeloplasty in 53 adult patients. Histopathological changes were graded on a scale of 1 to 3, according to their severity, and compared with the differential renal function (DRF) revealed on the preoperative and postoperative follow up diethylene triamine pentaacetic acid (DTPA) renal scan. A Fischer's t test was used to evaluate statistical differences between values.
  
  
  RESULTS
  This study showed a linear relationship between the severity of histological changes and renal function recovery, after pyeloplasty. Out of 24 obstructed renal units (ORU), with minimal histopathological changes (grade I), 21 ORU (87.5%), with > 35% DRF preoperatively, showed significant improvement in renal function after 12 months of pyeloplasty (P < 0.05). On the other hand, all kidneys (n = 29) with moderate to severe obstructive changes (grade II and III) had minimal improvement in DRF, after pyeloplasty, which was clinically insignificant (P > 0.05). Renal function deterioration after pyeloplasty was not observed in any of the cases.
  
  
  CONCLUSIONS
  The severity of pathological changes in renal parenchyma, due to UPJO, is a good predictor of renal function recoverability, after pyeloplasty. The ORUs, with DRF > 35%, usually have normal (grade I) renal biopsy and might be expected to present better functional recoverability after pyeloplasty.
authors.affiliation: Department of Urology, Indira Gandhi Institute of Medical Sciences, Patna, India.
authors.forename: Kaushal
authors.initials: K
authors.lastname: Kumar
authors.affiliation: Department of Urology, Indira Gandhi Institute of Medical Sciences, Patna, India.
authors.forename: Ahsan
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: Department of Urology, Indira Gandhi Institute of Medical Sciences, Patna, India.
authors.forename: Shailendra
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Pathology, Indira Gandhi Institute of Medical Sciences, Patna, India.
authors.forename: Vijyanand
authors.initials: V
authors.lastname: Choudhry
authors.affiliation: Department of Urology, Indira Gandhi Institute of Medical Sciences, Patna, India.
authors.forename: Rajesh Kumar
authors.initials: RK
authors.lastname: Tiwari
authors.affiliation: Department of Urology, Indira Gandhi Institute of Medical Sciences, Patna, India.
authors.forename: Mahendra
authors.initials: M
authors.lastname: Singh
authors.affiliation: Department of Urology, Indira Gandhi Institute of Medical Sciences, Patna, India.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Muzaffar
keywords: Biopsy; Hydronephrosis; Renal Pelvis; Ureteropelvic Junction Obstruction