large patient body habitus, unusual or deep location of the transplant, kidney or bowel loops surrounding the transplant kidney
Renal transplant biopsy
Xin Ye MD, Ana Maria Gomez MD, Steven Raman MD, David Lu MD, Justin McWilliams MD University of California, Los Angeles David Geffen School of Medicine Department of Radiology
Renal transplant survival is threatened by1: ◦ Rejection ◦ Acute tubular necrosis ◦ Infection ◦ Drug toxicity Imaging cannot differentiate between medical complications.
The diagnostic gold standard2-3. Risk of bleeding causing hematoma and hematuria. Goal of biopsy: target avascular renal parenchyma in lower pole cortex and avoid hilar structures and vessels. 2 biopsy techniques are used at UCLA.
Position and depth marked beforehand by US. 18 gauge core biopsy device is then advanced without real- time guidance. On site pathology tech assesses adequacy. Re-biopsy requires repeated punctures through the renal capsule.
Performed under real time US guidance. 17 gauge coaxial introducer is advanced through the renal capsule. 18 gauge core biopsy device is passed through the introducer. No re-puncturing of the renal capsule with re-sampling. Gelfoam embolization for hemostasis. Coaxial introducer advanced under US guidance1
Exclusion criteria: ◦ Severe anemia, platelets < 50,000 and prolonged PT with INR greater than 1.5 BP < 160/90 mm Hg. Diagnostic US ◦ Position, echotexture, renal vasculature, exclude hydronephrosis and perinephric fluid Nephrology typically refers more technically difficult patients to IR.
We compared the effectiveness and complications of two institutional renal biopsy techniques: the traditional “blind” technique versus a real time ultrasound (US) guided coaxial technique.
Retrospectively analyzed 608 patients who underwent 866 renal allograft biopsies between 7/28/2008 and 12/06/2010. Diagnostic quality of biopsy samples was assessed by review of pathology reports. Complications were determined from post-biopsy US reports and from review of patient notes for 2 weeks following biopsy. Minor complications: asymptomatic hematomas and arteriovenous fistulas (AVF’s), and minor hematuria. Major complications: complications requiring medical or surgical intervention.
Traditional CoaxialNumber of patients 415 193Number of biopsies 625 241Mean age 33 +/- 20 53 +/- 13Male 253 (61%) 119 (62%)Female 162 (39%) 74 (38%)
Traditional CoaxialInsufficient samples 6 (0.96%) 1 (0.41%) p = 0.68Minor complications 41 (6%) 5 (2.1%) p = 0.01 Hematoma, asymptomatic 25 2 AVF, asymptomatic 14 2 Hematuria, self limited 2 1Major complications 3 (0.5%) 2 (0.8%) p = 0.62
Traditional AVF leading to gross hematuria, bladder hematoma, and mild hydronephrosis. Resolved with IVF and bladder irrigation. Gross hematuria with a drop in Hg and urinary obstruction 2/2 bladder hematoma. Stabilized after IVF, foley, and pRBC transfusion. Large extracapsular hematoma after biopsy causing LLQ pain and renal compression that required surgical decompression.Coaxial Pt h/o MVR was restarted on heparin 12 hrs post-biopsy, became coagulopathic with PTT > 140. Developed a large subcapsular hematoma that lead to renal compression and renal failure. Required surgical decompression, dialysis, and transfusion. Hematoma, bleed at biopsy site, and drop in Hg after heparin was restarted 24 hr post op. Stabilized after heparin was held and IVF, pRBC transfusion were given.
No significant difference in rates of acquiring diagnostic samples. Both techniques demonstrate acceptably low risk of major complications without a significant difference. Traditional technique showed significantly higher rate of minor complications, which may or may not be of clinical significance.
1. Real Time Ultrasound Guided Coaxial Renal Transplant Biopsy with Gelfoam Injection for Hemostasis: Single Center Experience. Gomez AM, Raman SS, Anaya CA, Lu DS. Manuscript.2. Racusen L.C, Solez K, Colvin R.B, Bonsib S.M et al. The Banff 97 working classification of renal allograft pathology. Kidney International 1999; 55:713-723.3. JG Letourneau, DL Day, NL Ascher, WR Castaneda-Zuniga. Imaging of renal transplants. Am. J. Roentgenol 1988; 150:833-838.