Biopsy of the urinary tract requires a trained specialist (nephrologist, urologist, or interventional radiologist).
Renal biopsy
Indications for diagnostic biopsy include unexplained nephritic or nephrotic syndrome or acute kidney injury or concern for renal malignancy. Biopsy is occasionally done to assess response to treatment. Relative contraindications include bleeding diathesis and uncontrolled hypertension. Mild preoperative sedation with a benzodiazepine may be needed. Complications are rare but may include renal bleeding requiring transfusion or radiologic or surgical intervention.
Bladder biopsy
Bladder biopsy is indicated to diagnose certain disorders (eg, bladder cancer, sometimes interstitial cystitis or schistosomiasis) and occasionally to assess response to treatment. Contraindications include bleeding diathesis and acute tuberculous cystitis. Preoperative antibiotics are necessary only if active urinary tract infection (UTI) is present. The biopsy instrument is inserted into the bladder through a cystoscope; rigid or flexible instruments can be used. The biopsy site is cauterized to prevent bleeding. Based on the extent of the biopsy, a drainage catheter may be left in place to facilitate healing and drainage of clots. Complications include excessive bleeding, urinary retention, UTI, and bladder perforation.
Prostate biopsy
Prostate biopsy is usually done to diagnose prostate cancer. Contraindications include bleeding diathesis, acute prostatitis, and UTIs
Overlying structures (perineum or rectum) are anesthetized, a spring-loaded biopsy needle is inserted into the prostate, and tissue cores are obtained. Complications include the following:
Urosepsis
Hemorrhage (including hematuria and rectal bleeding)
Hematospermia (often for 3 to 6 months after biopsy)