This study compared the traditional "blind" renal transplant biopsy technique to an ultrasound-guided coaxial technique. The study found that both techniques obtained adequate biopsy samples in over 98% of cases. The traditional technique was associated with a significantly higher rate of minor complications like hematomas compared to the coaxial technique, but there was no significant difference in major complication rates between the two methods. Overall, both techniques demonstrated a low risk of complications and were effective in obtaining diagnostic biopsy samples.

1. Comparison of Traditional Renal Transplant Biopsy Technique
with Real Time Ultrasound Guided Coaxial Technique
Xin Ye, Ana Maria Gomez, M.D, Steven S. Raman, M.D, David S Lu, M.D, Justin P McWilliams, M.D.
Department of Radiology, David Geffen School of Medicine at UCLA
Introduction Methods Complication Rates:
Renal transplant survival is threatened by complications such as We retrospectively analyzed 459 patients who underwent Traditional Coaxial
rejection, acute tubular necrosis, infection, and drug toxicity. 667 renal allograft biopsies between 7/28/2008 and Minor complications 37 (7.3%) 3 (1.9%) p = 0.005
Percutaneous renal allograft tissue biopsy is the gold standard for 7/23/2010. Adequacy of biopsy samples was assessed in Major complications 2 (0.4%) 1 (0.6%) p=0.133
diagnosis but carries a risk of serious complications such as pathology reports. Complications were determined from
bleeding, AV fistula formation, and infection. post-op US reports and from patient notes for 2 weeks Minor Complications:
following biopsy. Minor complications were judged to be Traditional Coaxial
We compared the effectiveness and complications of two clinically asymptomatic hematomas, perinephric fluid Hematoma 22 2
institutional renal biopsy techniques: the traditional “blind” collections, AVF’s and hematuria, while major complications AVF 13 1
technique versus a real time ultrasound (US) guided coaxial were complications requiring medical or surgical Hematuria, self-resolved 2 0
technique. intervention.
Traditional Coaxial
Major Complications:
Number of Patients 354 132
Renal Biopsy Techniques Number of Biopsies 504 162 Traditional technique:
Median Age 27 (3-77) 54 (21-77) 1.) 13 yo M- AVF, gross hematuria, moderate hydronephrosis,
Traditional biopsy technique: performed by the nephrology
Males 215 (61%) 83 (63%) and clot in bladder post-biopsy. Resolved after 3 day stay w/
service, a biopsy needle is blindly advanced into the renal cortex at
Females 139 (39%) 49 (37%) bladder irrigation, foley, and IVF.
the lower pole of the kidney, guided by a skin marking and depth
2.) 53 yo F- gross hematuria, bladder hematoma causing
measurement determined beforehand by ultrasound (US). This Results obstruction, and decreased Hg 8.5 -> 7.1 post-biopsy. Resolved
technique punctures the renal capsule multiple times as several core after 2 day stay with Foley, IVF, and transfusion.
samples are needed for diagnosis. Per pathology, insufficient tissue was obtained in 6 out of
504 (1.2%) traditional biopsies and 1 out of 162 (0.6%) US- US-guided coaxial technique:
Results
Real time US guided coaxial technique: performed by the cross guided coaxial biopsies (no statistically significant 1.) 76 yo F- hx of MVR was restarted on heparin post-biopsy,
sectional interventional service (CSIR), a 17 g coaxial introducer difference). developed a large subcapsular hematoma requiring surgical
needle is advanced under real time US guidance into the renal Traditional Coaxial decompression., dialysis, and transfusion. Complicated by renal
Acute cellular rejection 303 43 rejection and hospitalized for 40 days before resolution.
cortex. The 18 g biopsy needle is then passed through the
introducer as many times as necessary without re-puncturing the Antibody-mediated rejection 103 60
Acute tubular necrosis 90 62
renal capsule
Interstitial fibrosis and tubular atrophy 81 26 Conclusions
No acute rejection 64 19
Nephrology typically refers to CSIR biopsies of patients with large Chronic transplant glomerulopathy 38 9 Both techniques had no significant difference in their rates
body habitus, unusually deep transplant kidney, bowel loops Focal segmental glomerulosclerosis 29 9 of acquiring diagnostic samples.
surrounding the kidney, or failure to acquire diagnostic tissue in Thrombotic microangiography 18 5
previous attempts. Diabetic nephropathy 14 8 Both techniques demonstrate acceptably low risk of major
IgA nephropathy 14 2 complications without a significant difference while the
Relative exclusion for biopsy were severe anemia, platelets < 50,000, Mild acute tubular injury 13 14 traditional technique showed significantly higher rate of
and prolonged PT with INR greater than 1.5. BK/polyomavirus interstitial nephritis 7 1
minor complications that may be of little clinical
Pyelonephritis 6 6
significance.
Membranous nephropathy 5 8