1. DEFENITION 2. History of Renal biopsy 3. Indications 4. C.I
5. Preparation for biopsy 6. Procedure 7. Post procedure 8.
Complications
Definition:- A renal biopsy is a procedure used to obtain a
segment of renal tissue, usually through a needle or another
surgical instrument.
History:- Before 1951, the only way of obtaining kidney tissue
from a live person was through an open operation. Danish physicians
Poul Iversen and Claus Brun described a method involving needle
biopsy which has become the new standard. Recent widespread
availability of real-time imaging guidance using ultrasound or CT
scanning having improved safety of the procedure.
Is the Biopsy Necessary? Always judge the balance of risk vs
benefit Most nephrologists would agree that renal biopsy is more
likely to change management in symptomatic kidney disease It can
also be useful for prognostic purposes, as well as helping to
direct or change treatment
Indications 1) Significant proteinuria (>1g/day)/Nephrotic
syndrome with two normal sized, non- obstructed, kidneys and no
obvious cause (usually considering the diagnosis of a glomerulo- or
interstitial nephritis) 2) Acute Kidney Injury (AKI) with two
normal sized, non-obstructed, kidneys and no obvious cause (pre and
post-renal causes excluded)or non resolving clinical ATN>3-4
weeks
3) Chronic Kidney Disease (CKD) with two normal sized,
non-obstructed, kidneys and no obvious cause 4) Renal transplant
dysfunction 5) Systemic disease with renal dysfunction
Less common (and more controversial) indications. (Many of
these patients may have normal renal function) Microscopic
haematuria Familial renal disease (where diagnosis in this patient,
benefits them and their family)
Diabetes and Renal Biopsy If the clinical presentation is
consistent with diabetic nephropathy (ie ,signficant proteinuria
[often nephrotic range], CKD3b- 4, diabetes of over 10 years
duration, presence of other microvascular complications [eg
retinopathy and neuropathy]) biopsy is not necessary and it can be
assumed that the patient has diabetic nephropathy (THE NEW TERM
DKD) why! When to biopsy diabetic patient : 1) Microscopic
hematuria 2) Absence of retinopathy and neuropathy 3) Onset of
significant proteinuria 80 years) suggesting that this is still a
useful technique with results that affect management in a
significant number of patients. There are racial differences
between biopsy appearances. For example, Hoy (2012) has described a
wide range of atypical findings in Australian aborginal
people.
Contraindications 6 Absolute 3 Relative
1) Uncorrectable bleeding diathesis 2) Uncontrollable severe
hypertension (>160/95) 3) Active renal or perirenal infection 4)
Skin infection at biopsy site 5) Presence of a solitary native
kidney(except in ) 6) Renal neoplasm, multiple cysts, abscess or
pyelonephritis
1) Certain anatomical abnormalities of the kidney (eg vascular
lesion) 2) Medications that interfere with clotting (e.g. warfarin
or heparin) 3) Pregnancy(safe before 30 w) 4) Uncooperative patient
(some consider absolute C.I)
Prior to the procedure Informed consent is usually taken.
Arrangements will also be made to ensure that appropriate
post-biopsy care and supervision is in place The patient has the
right to consent or decline
Before biopsy
NSAIDs should be stopped 24 hours before procedure. For
elective biopsies, anti-platelet agents (aspirin &clopidogrel)
should be stopped 7 days before the biopsy. Warfarin should ideally
be stopped 7 days before the procedure and the patient converted to
heparin if clinically indicated. Heparin (including prophylactic
and LMW) should be stopped at least 24 hours pre-procedure. Ideally
anticoagulation should not be restarted for 1 week post- biopsy. If
clinically indicated anticoagulation can be started after 24 hours,
but this should be delayed further if there is macroscopic
haematuria or a drop in haemoglobin.
Biopsy gun : 14 G guns gives greater number of glomeruli per
core than 18-G cores, but the rates of adequate biopsies were
similar Larger needle provided more tissue and glomeruli but were
associated with more pain. 16-gauge needles are used as a
compromise between the need of a sufficient size of tissue and the
need of clinical safety.
Biopsy sample is divided and sent off for: light microscopy ,
Immunoflourescence and Electron microscopy
Procedure Patient in prone position with wedge or pillow below
the abdomen Light sedation Local anesthesia with 1-2% lignocaine
subcutaneous Stab incision can be given to ease biopsy gun entry
Advance the biopsy gun, when the capsule is reached, instruct
patient to take a deep breath and fire the gun 2-3 cores can be
taken from the lower pole of the left kidney & placed in 10ml
of normal saline 0.9% and taken to the laboratory. Press on wound
for 2-5 minutes
Renal biopsy is typically performed by a nephrologist or
interventional radiologist
Post procedure Bed rest flat on back(4 hr) is instructed BP and
pulse are monitored in the following way:- Every 15 mins for 1 hour
Every 30 mins for 1 hour Every hour for 4 hours 4 hourly for next
remaining 24 hours Save each voided urine sample in clear specimen
container CBC & Hct monitored 6-8 hours and 18-24 hours after
biopsy
omplicationsC 1) Bleeding 2) AV fistula - these are common and
can be demonstrated by angiography in 10-20% of patients. Such
lesions are usually clinically silent, and more than 95% resolve
spontaneously within 2 years. In rare instances, embolisation or
surgical correction of the fistula is required because of severe
hypertension, persistent hematuria, congestive heart failure, or
hydronephrosis 3) Aneurysm - these occur in less than 1% of
patients and the majority resolve spontaneously Rarely they can
lead to significant ischaemic problems and may require
omplicationsCCont. 4) Biopsy of other organs (spleen, liver,
pancreas, bowel, gall bladder) 5) Calyceal-peritoneal fistula 6)
Dispersion of carcinoma 7) 'Page kidney' - compression of the
kidney by peri-renal haematoma leading to renin-mediated
hypertension
There is also an approximately 5% chance of obtaining an
inadequate tissue sample. In other words, from the patients'
perspective, the most important common complication of biopsy is
having to do it agaaaaaain
Haemorrhage The major complication of renal biopsy is bleeding.
A degree of peri-renal bleeding post-biopsy is inevitable and the
mean fall in haemoglobin after a renal biopsy is 1 g/dL Bleeds are
usually small and self-limiting and manifest as: Peri-renal
haematoma (Manno, 2004). Peri-renal haematomas are common, and
usually self limiting.. Non-visible haematuria (35%). Visible
haematuria (3%).
of a major bleedanagementM Tachycardia may be the first sign of
bleeding take it seriously Classic signs of shock and back pain may
happen much later If shock develops call your blood bank and
X-match 2 (or more) units of blood Ensure the patient has good
(wide bore) IV access, replace volume loss with IV saline/colloid
in the first instance Arrange an urgent ultrasound to see if there
is any bleed around the kidney (peri-renal haematoma). A CT
angiogram can be useful to identify both a peri-renal haematoma and
also the presence and site of active bleeding Occassionally heavy
haematuria may cause clot colic or acute urinary retention
Prolonged or severe bleeding may require angiography and coil
embolisation. It is sensible to inform the urologists at this stage
- if angiography and embolisation fail to stop the
bleeding.Nephrectomy will be required
Discharge & follow up Warn the patient they will feel sore
around the biopsy site for 3-4 days. Patients should be given clear
(written) instructions regarding pain and haematuria before they go
home. These should include 24 hour contact numbers in case of
complications that arise after discharge. All patients who have had
a renal biopsy should be seen in clinic soon after discharge:
Transplant biopsy: 1-2 days Native biopsy: 2 weeks
