Background: Kidney biopsy serves as an adjunct for diagnosis of renal disease nonetheless, kidney biopsy is not always productive due to technical failure (insufficient amount of material) or non-informative findings. Due to its invasiveness and risk, one should consider the benefit-risk ratio.
Aim: To evaluate the yield and risk of kidney biopsies performed during the last 2 decades in Schneider Children`s Medical Center.
Methods: The study group included pediatric patients who undergone closed percutaneous biopsy for various indications in native and transplanted kidneys in our institution between the years 1995-2014. Data on patient`s characteristics, technical and histo-pathological findings as well as the yield of biopsy – defined as positive (diagnosis confirmation or other contribution to disease management) or negative (technical failure or non-informative) and complications were collected from medical files.
Results: 216 native kidneys biopsies and 85 transplanted kidneys biopsies were performed in the study period (94 native kidneys in the first decade and 122 in the second and transplanted kidneys -32 and 53, respectively). No significant difference was found in the yield between the 2 groups - 86.6% in the group of native kidneys (8.3% technical failure and 5.1% non-informative) Vs 82.1% in the group of transplanted kidneys (14.3% technical failure and 3.6% non-informative). Significant differences were found between the groups in various technical and histo-pathological parameters (amount of glomeruli in biopsy, presence of crescents and presence of atherosclerosis in biopsy) as well as in patient`s characteristics (age at biopsy, gender distribution, presence of family history). In the group of native kidneys the most common indications for biopsy were SRNS, proteinuria and decreased GFR. Positive correlation was found between the presence of nephrotic-range proteinuria and the yield. Among the transplant biopsies the most common indication was decreased GFR and suspected rejection (83% of cases). Positive association was found between the amount of glomeruli and the yield from biopsy. Post procedural complications were noted in 3 patients (1.3%) in the native kidneys group and 1 (1.1%) in the transplants group.
Conclusion: Kidney biopsy is an efficient and safe diagnostic procedure in both native and transplanted kidneys.
