Recommended Citation
Kallarackel R, Thomas S, Thomas A. Kidney Biopsy Adequacy Analysis and Improvement Strategies. Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Abstract
Background/Significance:
Kidney biopsy remains the gold standard for diagnosis and management of patients with medical kidney diseases. Recent data suggest an increasing incidence of inadequate kidney biopsy samples in the United States. The Kidney Disease Improving Global Outcomes (KDIGO) guidelines recommend that an adequate kidney biopsy specimen should contain at least 8 glomeruli (KDIGO Glomerular Diseases Work Group, 2021).
Purpose:
Improving kidney biopsy adequacy is essential to ensure accurate diagnosis, reduce repeat procedures, and optimize outcomes. Optimizing procedural techniques targeting the outer renal cortex and selecting larger-gauge needles—has been shown to improve tissue adequacy. Standardizing biopsy protocols, enhancing operator training, and incorporating routine quality improvement reviews can further reduce variability. Patient-specific factors such as advanced age or cortical thinning warrant tailored biopsy planning and enhanced intra-procedure adequacy review.
Methods:
We retrospectively analyzed the adequacy of kidney biopsies performed at our institution between January 2021 and June 2023. Adequacy was defined according to KDIGO criteria.
Results:
A total of 381 kidney biopsies were included in the analysis. The cohort consisted of 218 females (57.2%) and 163 males (42.8%), with a mean age of 55 years (range 5–93 years). African American patients represented 182 cases (47.8%). Using the predefined adequacy threshold, 91 biopsies (23.9%) were deemed inadequate. Despite this, a definitive pathological diagnosis was achieved in 48 of these inadequate samples (52.7%). A diagnosis was not possible in 43 cases (11.2%), so a second biopsy was advised. Notably, 48 patients (52.7% of those with inadequate biopsies) were over 60 years of age.
Conclusion:
The high proportion of non-diagnostic kidney biopsies (11.2%) has several important clinical implications. Inadequate tissue sampling may delay diagnosis and initiation of appropriate therapy. Although over half of inadequate specimens still yielded a diagnosis, patients without sufficient tissue may require repeat biopsy, adding risk, cost, and anxiety. Older adults, particularly those over 60, were disproportionately affected, highlighting a need for modified biopsy strategies such as optimized imaging guidance, or real-time adequacy evaluation. Quality improvement measures in biopsy technique, operator training, and real-time assessment are essential for ensuring high-quality diagnostic tissue.
Presentation Notes
Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Full Text of Presentation
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Document Type
Oral/Podium Presentation
Kidney Biopsy Adequacy Analysis and Improvement Strategies
Background/Significance:
Kidney biopsy remains the gold standard for diagnosis and management of patients with medical kidney diseases. Recent data suggest an increasing incidence of inadequate kidney biopsy samples in the United States. The Kidney Disease Improving Global Outcomes (KDIGO) guidelines recommend that an adequate kidney biopsy specimen should contain at least 8 glomeruli (KDIGO Glomerular Diseases Work Group, 2021).
Purpose:
Improving kidney biopsy adequacy is essential to ensure accurate diagnosis, reduce repeat procedures, and optimize outcomes. Optimizing procedural techniques targeting the outer renal cortex and selecting larger-gauge needles—has been shown to improve tissue adequacy. Standardizing biopsy protocols, enhancing operator training, and incorporating routine quality improvement reviews can further reduce variability. Patient-specific factors such as advanced age or cortical thinning warrant tailored biopsy planning and enhanced intra-procedure adequacy review.
Methods:
We retrospectively analyzed the adequacy of kidney biopsies performed at our institution between January 2021 and June 2023. Adequacy was defined according to KDIGO criteria.
Results:
A total of 381 kidney biopsies were included in the analysis. The cohort consisted of 218 females (57.2%) and 163 males (42.8%), with a mean age of 55 years (range 5–93 years). African American patients represented 182 cases (47.8%). Using the predefined adequacy threshold, 91 biopsies (23.9%) were deemed inadequate. Despite this, a definitive pathological diagnosis was achieved in 48 of these inadequate samples (52.7%). A diagnosis was not possible in 43 cases (11.2%), so a second biopsy was advised. Notably, 48 patients (52.7% of those with inadequate biopsies) were over 60 years of age.
Conclusion:
The high proportion of non-diagnostic kidney biopsies (11.2%) has several important clinical implications. Inadequate tissue sampling may delay diagnosis and initiation of appropriate therapy. Although over half of inadequate specimens still yielded a diagnosis, patients without sufficient tissue may require repeat biopsy, adding risk, cost, and anxiety. Older adults, particularly those over 60, were disproportionately affected, highlighting a need for modified biopsy strategies such as optimized imaging guidance, or real-time adequacy evaluation. Quality improvement measures in biopsy technique, operator training, and real-time assessment are essential for ensuring high-quality diagnostic tissue.
Affiliations
Advocate Christ Medical Center