Renal biopsy

Renal biopsy

1. Dr. Hanan Mostafa Nephrology Specialist New Mansoura General Hospital Renal Biopsy

2. Introduction. Aim of renal biopsy. Indications for renal biopsy. Contraindications for renal biopsy. Workup for r enal b iopsy . Renal biopsy procedure . Biopsy adequacy . Post biopsy m onitoring. Renal biopsy complications. Agenda

3. Definition: A renal biopsy is a procedure used to obtain a segment of renal tissue , usually through a needle or another surgical instrument . Percutaneous renal biopsy was first described in the early 1950s . Renal biopsy is now able to provide a tissue diagnosis in more than 95% of patients , with a life-threatening complication rate of less than 0.1% Introduction

4. It may be done to determine: - Cause. - Severity. - Treatment of a kidney disorder. - Prognosis. Renal biopsy identifies a diagnosis different from that predicted on clinical grounds in 50% to 60% of patients and leads to a treatment change in 20% to 50 %. Aim Of R enal B iopsy

5. Adult nephrotic syndrome. Nephrotic children with atypical features : - Microscopic hematuria. - Reduced serum complement levels. - Renal impairment. - Failure to respond to corticosteroids . Indications

6. Isolated non nephrotic proteinuria (> 1 g/24 h): Indications - The value of renal biopsy in patients is debatable. - All conditions that result in nephrotic syndrome can cause non-nephrotic proteinuria, except MCD. - In patients with proteinuria of more than 1 g/day, treatment with strict blood pressure control and (ACE) inhibitors or (ARBs) reduces proteinuria and reduces the risk for progressive renal dysfunction .

7. Isolated glomerular hematuria: Indications - IgA nephropathy is the most common lesion, followed by thin basement membrane . - In the absence of nephrotic proteinuria, renal impairment, or hypertension, the prognosis is excellent . - As no specific therapies are available, renal biopsy is not necessary and patients require only follow-up.

8. Unexplained acute or rapidly progressive renal failure. Certain cases of unexplained chronic renal failure. Renal allograft dysfunction Renal transplant rejection. Systemic diseases with renal involvement: - Small-vessel vasculitis. - Anti–glomerular basement membrane disease. - Systemic lupus. Indications

9. Indications 30 y, DM type 1 (15y), Nephrotic range proteinuria, N. S.Cr , eGFR more than 60,No retinopathy, Macroscopic hematuria. 30y, DM type 1(15y), Nephrotic range proteinuria, N. S.Cr , eGFR more than 60, Retinopathy. 55y, normotensive, proteinuria 1 gm , US normal, normal S.Cr , normal immunology. 55y, normotensive, proteinuria 1 gm , US normal, normal S.Cr , ANA + ve . 45y,BMI 40, BP 150/100, proteinuria 4 gm , S.Cr normal, S. Alb. 3.9, normal US, Normal immunology .

10. Absolute Patient Refusal. Bleeding diathesis. Uncontrolled severe hypertension. Contraindications Azotemia. Anatomical abnormalities of the kidney(multiple cysts). skin infection. Hemostasis-altering drugs. pregnancy. urinary tract infections. obesity. Uncooperative patient. Solitary native kidney. Small sized kidney. Relative

11. Contraindications

12. Informed Consent Answering 5W Questions What? Why? How? What is the risk benefit? What are the precautions? Workup For R enal B iopsy

13. Workup For R enal B iopsy

14. Biopsy is performed by nephrologists with ultrasound guidance and disposable automated biopsy needles . We use 16-gauge needles and the trend toward fewer bleeding complications of smaller needles. For most patients, premedication or sedation is not required . The patient is prone, and a pillow is placed under the abdomen at the level of the umbilicus to straighten the lumbar spine and to splint the kidneys . Renal Biopsy P rocedure

15. Renal Biopsy P rocedure Ultrasound is used to localize the lower pole of the kidney where the biopsy will be performed (usually the left kidney). A pen mark is used to indicate the point of entry of the biopsy needle. The skin is sterilized with povidone-iodine (Betadine) . A sterile fenestrated sheet is placed over the area to maintain a sterile field. Local anesthetic (2% lidocaine ) is infiltrated into the skin at the point previously marked.

16. Renal Biopsy P rocedure While the anesthetic takes effect, the ultrasound probe is covered in a sterile sheath. Sterile ultrasound jelly is applied to the skin Under ultrasound guidance, a 10-cm, needle is guided to the renal capsule . A stab incision is made through the dermis to ease passage of the biopsy needle. This is passed under ultrasound guidance to the kidney capsule .

17. Renal Biopsy P rocedure As the needle approaches the capsule, the patient is instructed to take a breath until the kidney is moved to a position such that the lower pole rests just under the biopsy needle, and then to stop breathing. The biopsy needle tip is advanced to the renal capsule, and the trigger mechanism is released, firing the needle into the kidney . The needle is immediately withdrawn, and the contents of the needle are examined .

18. Renal Biopsy P rocedure The biopsy needle is introduced at an angle of 70 degrees to the skin and is guided by continuous ultrasound.

19. Renal Biopsy P rocedure

20. Renal Biopsy P rocedure We are examining the tissue core under an operating microscope to ensure that renal cortex has been obtained. A second pass of the needle is usually necessary to obtain additional tissue for immunohistology and EM . If insufficient tissue is obtained, further passes of the needle are made. However, passing the needle more than four times is associated with a modest increase in the post biopsy complication rate. Once sufficient renal tissue has been obtained, the skin incision is dressed and the patient rolled directly into bed for observation.

21. Renal Biopsy P rocedure

22. Renal Biopsy P rocedure renal tissue is divided into three samples and placed in # Formalin for light microscopy # Normal saline for immunofluorescence # Glutaraldehyde for EM Some centers are able to produce satisfactory light microscopy, immunohistochemistry, and EM on formalin-fixed biopsy material, this depends on the expertise of individual laboratories.

23. Renal Biopsy P rocedure Renal Transplant Biopsy Biopsy of the transplant kidney is facilitated by the proximity of the kidney to the anterior abdominal wall and the lack of movement on respiration . It is performed under real-time ultrasound guidance with use of an automated biopsy needle . In most patients, renal transplant biopsy is performed to identify cause of acute allograft dysfunction (acute rejection), therefore diagnosis can be made on a formalin fixed sample alone for light microscopy . If vascular rejection is suspected, a snap-frozen sample for C4d immunostaining should also be obtained (although some laboratories are able to detect C4d on formalin-fixed material). If recurrent or de novo GN is suspected in patients with chronic allograft dysfunction, additional samples for EM and immunohistology should be collected.

24. Biopsy Adequacy An adequate biopsy should provide samples for: immunohistology and electron microscopy (EM). A typical diagnostically useful biopsy sample will contain 10 to 15 glomeruli . Cortex and medulla 1-2 glomeruli EM 3-5 glomeruli IF 6 glomeruli ( native kidney) 10 glomeruli (renal allograft)

25. Stains

26. 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 lay 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. Post Biopsy Monitoring

27. Complications Dull ache Pain. Perirenal hematomas . Visible hematuria. Arteriovenous fistulas. Death.

28. Complications

29. Thank You