Most often, a doctor performs a kidney biopsy by inserting a thin needle through the skin. This is called a percutaneous kidney biopsy. An imaging device helps the doctor guide the needle into the kidney to remove tissue.

Why it's done

A kidney biopsy may be done to:

• Diagnose a kidney problem that can't otherwise be identified
• Help develop treatment plans based on the kidney's condition
• Determine how quickly kidney disease is progressing
• Determine the extent of damage from kidney disease or another disease
• Evaluate how well treatment for kidney disease is working
• Monitor the health of a transplanted kidney or find out why a transplanted kidney isn't working properly.

Your doctor may recommend a kidney biopsy based on the results of blood or urine tests that show:

• Blood in the urine originating from the kidney
• Protein in the urine (proteinuria) that's excessive, rising or accompanied by other signs of kidney disease
• Problems with kidney function, leading to excessive waste products in the blood

Not everyone with these problems needs a kidney biopsy. The decision is based on your signs and symptoms, test results, and overall health.

Risks

In general, percutaneous kidney biopsy is a safe procedure. Possible risks include:

How you prepare

Before your kidney biopsy, you'll meet with your doctor to talk about what to expect. This is a good time to ask questions about the procedure and make sure you understand the benefits and risks.

Medications

When you meet with your doctor, bring a list of all medications you take, including over-the-counter medications, vitamins and herbal supplements. Before your kidney biopsy, you'll be asked to stop taking medications and supplements that can increase the risk of bleeding. These include:

• Blood-thinning medications, such as warfarin (Coumadin, Jantoven), rivaroxaban (Xarelto), dabigatran (Pradaxa) or enoxaparin (Lovenox)
• Drugs that keep blood platelets from excessively sticking together, such as clopidogrel (Plavix)
• Aspirin
• Ibuprofen (Advil, Motrin IB, others) and other nonsteroidal anti-inflammatory drugs (NSAIDs)
• Certain dietary supplements, such as omega-3 fatty acids

Your doctor or nurse will let you know when to stop taking these medications and supplements, and for how long. Often, these medications are stopped seven days before the procedure and then started again seven days after the procedure.

Blood and urine samples

Before your biopsy, you'll have blood drawn and provide a urine sample to make sure you don't have an infection or another condition that would make the biopsy risky.

Diet

You may be asked not to drink or eat for eight hours before the kidney biopsy.

What you can expect

You'll have a kidney biopsy at a hospital or outpatient center. An IV will be placed before the procedure starts. Sedatives may be given through the IV.

During the procedure

During the biopsy, you'll be awake and lie on your abdomen or your side, depending on which position allows best access to your kidney. For a biopsy of a transplanted kidney, most people lie on their backs. A percutaneous biopsy includes these steps:

• With an ultrasound probe, your doctor identifies exactly where to insert the needle. In some cases, a CT scan may be used instead of ultrasound.
• Your doctor marks your skin, cleans the area and applies a numbing medication (local anesthetic).
• Your doctor makes a small incision where the needle will go in and uses the ultrasound device to guide the needle into your kidney.
• You may be asked to hold your breath as your doctor collects a sample using a spring-loaded instrument. You may feel a "pop" or pressure and hear a sharp clicking noise.
• Your doctor may need to insert the needle several times — often through the same incision — to get enough tissue.
• Your doctor removes the needle and places a small bandage on the incision.

Other kidney biopsy procedures

Percutaneous kidney biopsy isn't an option for some people. If you have a history of bleeding problems, have a blood-clotting disorder or have only one kidney, your doctor may consider a laparoscopic biopsy.

In this procedure, your doctor makes a small incision and inserts a thin, lighted tube with a video camera at its tip (laparoscope). This tool allows the doctor to view your kidney on a video screen and remove tissue samples.

After the procedure

After the biopsy, you can expect to:

• Significant bright red blood or clots in your urine more than 24 hours after the biopsy
• Changes in urination, such as an inability to pass urine, an urgent or frequent need to urinate, or a burning sensation when urinating
• Worsening pain at the biopsy site
• Fever over 100.4 F (38 C)
• Faintness or weakness

Results

It may take up to a week before your doctor has your biopsy report from the pathology lab. In urgent situations, a full or partial report may be available in less than 24 hours.

Your doctor will usually discuss the results with you at a follow-up visit. The results may further explain what's causing your kidney problem, or they may be used to plan or change your treatment.

Dialysis Catheter

A dialysis catheter is a catheter used for exchanging blood to and from a hemodialysis machine and a patient.

The dialysis catheter contains two lumens: venous and arterial. Although both lumens are in the vein, the "arterial" lumen, like natural arteries, carries blood away from the heart, while the "venous" lumen returns blood towards the heart. The arterial lumen (typically red) withdraws blood from the patient and carries it to the dialysis machine, while the venous lumen (typically blue) returns blood to the patient (from the dialysis machine). Flow rates of dialysis catheters range between 200 and 500 ml/min.

If a patient requires long-term dialysis therapy, a chronic dialysis catheter will be inserted. Chronic catheters contain a dacron cuff that is tunneled beneath the skin approximately 3–8 cm. The tunnel is thought to add a barrier to infection. The most popular dialysis catheter sold on the market today is the Symmetrical-Tip dialysis catheter. This catheter is in the form spiral Z shape.

Permacath for dialysis

Temporary access Central venous catheters used for temporary access are typically used for less than 21 days. These types of catheters are usually smaller in size, placed directly in the vein, and are two or three lumens in design. The third lumen is useful for administration of fluids, antibiotics, medicines, or contrast without having to find other places for intravenous access. This type of catheter is useful for initiating venous access for acute renal failure patients quickly for dialysis before a permanent catheter is inserted for long term access.

Permanent access The lumens of this type of catheter is larger, have a cuff that tunnel under the skin away from the venous insertion site with only two lumens. The catheter course under the skin helps to prevent infection going into bloodstream, as seen in temporary catheters.[1]

Catheter placement

Common site of catheter placement is placed by puncturing the right internal jugular vein (IJV) in the neck, advancing into superior vena cava (SVC) towards the right atrium of the heart due to its straightforward path into the SVC. Alternatively, a SVC catheter can be inserted via the right external jugular vein (EJV) if right IJV is inaccessible. If both IJV and EJV are both not accessible, left IJV can be assessed. However, left IJV access is more difficult that right IJV because of its tortuous course to the SVC.

Complications

Some common malfunctions of dialysis catheters include clotting, infection, and kinking. One of the most common errors of tunnel hemodialysis catheter insertions is failure to locate the arterial limb of the catheter medially and the venous limb laterally. This must be done, because most catheters have a memory in the plastic, which will cause the catheter to try to resume its natural straight form. If the arterial limb is placed laterally, this will cause the arterial inlet to float up against the vein wall, or even up against the rim of the inlet of the atrium. This has the same effect as a vacuum cleaner hose sucking up against curtains. This results in poor blood flows, and can force the dialysis staff to reverse flow, using the venous limb of the catheter as the arterial. This will result in more inefficient dialysis, as there will be admixing of blood from the catheter (cleaning the same blood, over again). A dialysis catheter must have infusion of 30cc or greater to keep the line open. Intravenous fluids at 30ml per hour should be hung if being used for infusion.