What Are MIIPs? / Blocked Urinary Tract

What do kidneys do?

Most people are born with two kidneys, one on either side of the body near the mid back. Kidneys filter the blood to get rid of extra water, waste and toxins through the urine. Urine drains from the kidneys into the bladder through two small tubes called the ureters.

Kidney stones, cancer, and scarring can block a ureter and prevent the flow of urine into the bladder. If a ureter gets blocked, urine will back up in the kidney and not be able to get out. The pressure of the backed-up urine can damage the kidney temporarily or permanently. A drain has to be placed to get the urine out and save the kidney. This drain is called a nephrostomy tube.

What is a nephrostomy tube and why is it used?

A nephrostomy tube is a small tube that is put into the kidney through a tiny hole in the skin of the mid back. If a blockage in the ureter prevents urine from draining from the kidney to the bladder, then a nephrostomy tube can be placed to drain the kidney. This tube drains the urine that is made in the kidney to a bag outside the body. The bag can be emptied as it fills up. Patients can sleep and shower with the tube and the bag.

What are ureteral stents and why are they used?

Some patients have a damaged ureter or have a blocked ureter but, with help, can drain into their bladder instead of into a bag. These people could benefit from a ureteral stent. A ureteral stent is a soft tube placed inside the ureter with one end in the kidney and the other end in the bladder. The ureteral stent opens up the blocked ureter, allowing urine to drain from the kidneys to the bladder. The stent has a pigtail curl at each end to keep it in place.

A nephroureteral stent is like a nephrostomy tube and ureteral stent, all-in-one. One end sticks out of the back and can be used to drain urine to a bag. The other end extends into the bladder, so the patient can drain into the bladder. It is sometimes used to transition patients from a nephrostomy tube to a ureteral stent.

How are these two procedures performed?

Nephrostomy tubes and ureteral stents are placed through MIIPs (minimally invasive, image-guided procedures) performed by an Interventional Radiologist (IR) or a Urologist. Usually you can have the procedure and leave the same day or the next day.

If done by an IR, you will most likely get sedation to make you sleepy and comfortable but you will still able to breathe on your own. You will lay flat on your belly. The skin on your back will be cleaned and prepared. The IR will numb the skin with medication and use imaging (ultrasound or low dose x-rays) to find the kidney. The IR will then insert the tube through the skin and into the kidney. Moving x-rays and contrast dye help the IR position the tube properly. The dye also reveals where the blockage is. If the blockage is due to a scar, the IR may use a tiny balloon to stretch it open.

If you have a nephrostomy tube or nephroureteral tube, the drain exiting your back will be attached to a bag to collect the urine. The nurse will show you how to empty and care for the bag. The tube will be removed when it is no longer needed.

If you have a ureteral stent placed or once the tube is removed, there will be no tube coming out of the back. A bandage will be placed over the small nick on your back. You can remove this bandage the next day.

Are there risks to these procedures?
  • Infection: Any time there is a break in the skin, there is a risk of infection. Antibiotics are usually given because the blocked urine is often infected.

  • Bleeding: The kidney has a rich blood supply, so there is a risk of bleeding.

  • Damage to surrounding structures like the intestines, liver and spleen. Medical imaging is used to help the specialist avoid damaging these structures.

The benefits of these procedures usually outweighs the risks because they allow urine out of the kidney, which is necessary to prevent kidney damage.

For more information on MIIPs to drain the kidneys:
Sometimes a blockage due to a kidney stone or something else can cause a severe urinary tract infection. 
For more information about kidney stones and infections:

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