Equipment
Anesthesia
Percutaneous renal biopsy (PRB) is performed under local anesthesia using 1% lidocaine.
Positioning
For PRB of native kidneys, the patient is placed in the prone position, usually with a towel or pillow placed underneath the abdomen to ensure appropriate positioning.
For PRB of the transplant graft, the patient sleeps supine and the biopsy is performed in the right or left lower quadrant depending on where the kidney was transplanted.
Monitoring & Follow-up
Postprocedural care
After the physician has finished obtaining all the tissue for the biopsy, the needle is removed and pressure is applied to the biopsy site to tamponade any potential bleeding, and, finally, a bandage is applied.
The patient should typically lie supine in bed for 6-8 hours immediately after the procedure. In total the patient should expect to stay in the hospital for at least 12 hours and may have to spend one night in the hospital after the procedure. During this time, the patient will be given proper pain medication, urine will be checked for blood, and blood counts and vital signs will be monitored throughout the patient’s stay in the hospital. [14]
Complications
The most common complication of renal biopsy is pain and bleeding at the biopsy site.
Bleeding may occur in 3 distinct locations within the kidney: into the collecting system, under the renal capsule, or into the perinephric space. If the bleeding enters the collecting system, blood is seen in the urine and can cause pain and obstruction. If the bleeding is subcapsular, it can create enough of a mechanical compressive effect onto the kidney to cause hypertension owing to an increase in the release of renin, which is a hormone that is secreted by the juxtaglomerular apparatus of the kidney in the proximal convoluted tubule to increase systemic blood pressure. [4]
Subcapsular hematomas in transplanted kidneys are worrisome, and one should make sure that kidney perfusion is not compromised by the compression effect that might cause graft thrombosis and loss.
The injured kidney can also undergo fibrosis and, ultimately, chronic hypertension and perhaps even renal failure can result if the contralateral kidney is compromised. This phenomenon is known as the Page kidney effect after Dr Irvine Page, who first demonstrated in 1939 that wrapping cellophane tightly around animal kidneys can cause hypertension. [15] Perinephric bleeding can ultimately cause hemodynamic instability as it continues to pool in the retroperitoneal space, necessitating blood transfusion.
Another known complication of a renal biopsy is the development of an arteriovenous fistula. Up to 18% of patients undergoing renal biopsy may develop this complication. [16] However, in most cases, the arteriovenous fistula is asymptomatic and heals before causing symptoms. Nonetheless, some patients may experience symptoms such as hematuria, hypertension, and renal insufficiency. It is important to treat symptomatic fistulas as soon as possible to prevent further deterioration. Treatment consists of selective angioembolization performed by a vascular interventional radiologist to halt the bleeding. [16]
The image below depicts perinephric hematoma after renal biopsy.
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Perinephric hematoma after a renal biopsy.
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Ultrasound-guided percutaneous renal biopsy to obtain kidney tissue for diagnosis.
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CT-guided biopsy of a renal mass.
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Renal biopsy specimen shows focal segmental glomerulosclerosis on histopathologic examination.
