Theoretical calculation of optimal depth in the percutaneous native kidney biopsy to drastically reduce bleeding complications and sample inadequacy for histopathological diagnosis

Abstract

Of our series of 126 consecutive PNKD using the mathematical formula (Group I), only four subjects presented post-biopsy gross haematuria (3.2%) and three experienced symptomatic small subcapsular haematoma (2.4%). All biopsy specimens proved to be adequate for diagnosis (100%) with a mean of 22 glomeruli (range 5-60) per specimen. The previous series of 123 consecutive PNKB (Group II) showed gross haematuria (8.4%; P < 0.01 vs Group I) and symptomatic subcapsular haematoma (3.7%) with an adequate sampling of 94.8% (P < 0.01 vs Group I) and a mean glomerular count of 17 (range 4-47) per specimen (P < 0.01 vs Group I). Conclusions. PNKB is an invasive procedure that in spite of progress made in safety, diagnostic adequacy and performing techniques, still involves minor or major risks. The results obtained show that our method is extremely useful to reduce significantly the incidence of bleeding complications and permits us to take enough renal tissue for diagnostic evaluation in all cases.

When Size Matters: Diagnostic Value of Kidney Biopsy according to the Gauge of the Biopsy Needle

“…We slightly modified the technique, which was described earlier for kidney allografts [5]. Under visual control, the full length of the biopsy needle side notch was inserted into the renal cortex between the renal capsule and the corticomedullary junction [5,6]. The puncture angle was between 20 and 30° [7].…”

Nephrology and the Percutaneous Renal Biopsy

“…Throughout the years, improvements in imaging techniques and biopsy needles have resulted in the ability to obtain adequate renal tissue for diagnosis in .95% of renal biopsies (7)(8)(9)(10)(11). Additionally, these technical improvements have led to increased safety of the procedure: the rate of complications resulting in death decreased from 0.12% to 0.02% during the last 50 years (7,12).…”

Comments and extensions to EFSUMB guidelines on renal interventional ultrasound (INVUS).

“…Either direct measurement or formulas should be applied [28] to predetermine the required needle length. Patients should be warned of potentially frightening noises upon release of the spring-loaded device before employment, to reduce the risk of movement.…”

“…The outer scale on the biopsy gun should be used as a guide. Formulas to calculate the optimal depth of the needle insertion are available and reduce bleeding complications [28]. The final positioning of the needle should avoid bending and consecutively high sheer forces between needle and outer cannula.…”