Renal transplant biopsy

Biopsy is a valuable tool in the postoperative management of the transplant patient , enabling the cause of graft dysfunction to be identified, in particular differentiating acute tubular necrosis from acute rejection. Ultrasound guidance
is essential in order to reduce complications such as haematoma, vascular damage (which may result in arteriovenous fistula or pseudoaneurysm formation)
and laceration of the renal collecting system.
A single-pass technique, using the spring-loaded biopsy gun with a 16-gauge needle, is usually sufficient for histological purposes; however two passes are often required so that electron microscopy and immunofluorescence can also be
perfomed. The procedure is well tolerated by the patient and the complication rate low, at less than 5% A full scan of the kidney is first performed to highlight potential problems, for example perirenal fluid collections, and to establish the safest and most effective route. The transplanted kidney lies in an extraperitoneal position and the chosen route should avoid puncturing the peritoneum, to minimize the risk of infection. Unlike the native kidney, the upper pole of the transplanted kidney is usually chosen to avoid major blood vessels and the ureter, which pass close to
the lower pole.
The biopsy aims to harvest glomeruli, and the chosen route should therefore target the renal cortex. An angle is chosen to include the maximum thickness of cortex and, where possible, avoid the renal hilum (Fig.ultrasound images below).

The transplanted kidney lies in the iliac fossa and is biopsied with the patient supine

 

 

 

The needle is seen entering a transplanted kidney (arrowheads).

Ultrasound Tags: Renal transplant biopsy