Your specialist has recommended that you have a CT-guided drainage. This information leaflet will explain what it is, what it involves and the possible risks. The aim is to provide you with as much help and information as possible before you have your procedure.
What is a CT-guided drainage?
An abscess is a collection of pus that has formed within the body. The main symptoms and signs of an internal abscess include pain in the affected area, a high temperature, and generally feeling unwell.
In the past, drainage of an abscess (or “collection” as it is often called by doctors) inside your chest or abdomen would have required an open operation. Now it is possible to drain collections by inserting a plastic tube(s) called a drainage catheter, into the abscess/collection through the skin, with only a tiny cut. This procedure is called a “percutaneous” (through the skin) abscess drainage.
Why do I need this procedure?
Internal abscesses rarely heal themselves, so prompt medical attention is required if such an abscess is diagnosed. Antibiotics can’t easily penetrate an abscess to enable healing and a drain is often required to remove the contents and allow the antibiotics to do their job.
Are there any alternatives?
The alternatives to having a drain inserted are an operation, (which usually carries significantly more risk and longer recovery times) and very occasionally prolonged treatment with antibiotics.
What are the risks?
A CT-guided drainage is a common procedure performed frequently in Leeds Teaching Hospitals NHS Trust. The most common problem encountered is mild pain, which can be controlled with simple painkillers.
There is a risk that we won’t be able to completely drain your collection. This can be due to a variety of reasons; it may be that it is difficult to gain safe access because other important structures are in the way; sometimes the collection has multiple compartments and we can’t drain all of them and occasionally the fluid is too thick to be drained through the plastic tube we insert.
Other risks include superficial infection at the skin puncture site, local scarring at the puncture site, blockage of the tube and bleeding.
Another very rare but serious complication is damage to other organs in the abdomen such as blood vessels, the liver or bowel, which could require an operation. The vast majority take place without any problems or complications.
What will happen before my procedure?
There are usually no specific pre procedure requirements – please continue to eat and drink as normal unless otherwise advised.
Blood tests
You will need to have a blood test to check how well your blood clots. This is important, as if your blood is too thin, it may not be safe to perform the procedure due to an increased risk of bleeding.
Medications
Your regular medications, including any you have bought without prescription at your local pharmacy will need to be reviewed. Medications that thin the blood may need to be stopped in advance of the procedure, which your doctor will tell you about and check before the drainage is done.
What does the procedure involve?
A specially trained doctor called a radiologist will perform the procedure. They will start by confirming that you understand the benefits, risks and associated complications of the procedure and that you are willing to have the procedure.
If there is anything that you are unsure about or want to clarify, please do not hesitate to ask.
You will be asked to lie on the CT scanning table, in a position that the radiologist has determined is most suitable.
The radiologist will use the CT scan images to decide on the most suitable point for inserting the drainage tube. They will accurately mark this point with a pen using the lights on the scanner to guide them. The radiologist will keep everything as sterile as possible, and may wear a theatre gown and operating gloves. They will clean the skin with an antiseptic solution and give you an injection of local anaesthetic, which goes into the skin and deeper.
This will sting briefly before going numb. Local anaesthetic works quickly and you should not feel any pain, although there may still be some discomfort during insertion of the tube.
What happens next will vary in different situations. Any pus may simply be drained through the needle (aspirated), or a slightly larger needle or plastic tube, which is then withdrawn altogether. Alternatively, it may be necessary to place a larger drainage tube (catheter) into the collection and attach it to the skin, with a special dressing, so that the pus can continue to drain for several days.
While the first part of the procedure may seem to take a while, actually performing the percutaneous drainage does not take very long at all, using the CT scans to accurately guide the needle/catheter into position. You must keep as still as possible during this stage – if it becomes too uncomfortable please let us know.
What happens after my procedure?
After your procedure you will return to your ward for monitoring and continued care and your drain will be removed after sufficient fluid has drained and when there are signs that your body is recovering from the infection.
It is quite normal to experience some mild discomfort over the drainage site after the tube has been removed, which can last up to a week. This usually responds to simple painkillers, which you can ask for at any time.
What do I do when I get home?
You should avoid strenuous exercise, lifting and driving for a couple of days. You can eat and drink as normal. You can shower but only with a waterproof dressing in place.
If you develop a temperature or redness around the skin puncture site or experience pain that is not settling with painkillers, please contact either:
- Your local GP
- NHS Direct – on 111
- Your local A&E department