Many individuals develop infections and sometimes these infections are not adequately treated or they are missed and the result is the development of pus (Abscess). Pus collections can also occur as a result of surgery and may occur anywhere in the body. When these collections of pus are not drained, the individual continues to be sick and can not recover. Pus collections can continue to cause systemic illness, weight loss, fever and other infections in the body. In the old days, the only way to drain pus was with surgery. The surgery to drain pus is a major undertaking. Today, image guided techniques are available which are more efficient, effective, less invasive and safer than surgery. Ct guided drainage of abscess can be done almost anywhere in the body. It can access pus pockets which can't be accessed with surgery. CT guided drainage procedures are done by a radiologist trained in invasive procedures.
Where in the body can CT guided drainage be used to drain pus?
Abscess collections can be drained almost anywhere in the body and the most common sites include:
- chest cavity
- abdominal cavity
- pancreas, kidney, liver
- beneath the diaphragm
- lower pelvic
- neck area
Who is a candidate for CT guided drainage of Abscess?
There are no set guidelines as to who is a candidate but anyone of the following candidates should be preferred for CT guided drainage:
- individuals who develop pus after appendectomy
- individuals who get pus anywhere in the abdomen
- individuals who develop localized collections of pus either in the chest or abdomen
- individuals who have collections of pus in their legs, esp. thighs
- individuals who have a lung infection with an abscess
- individuals who have a liver, spleen or kidney abscess
- individuals who are not candidates for surgery
- individuals who have collection of pus in areas not accessible by surgery
What preparation is needed?
Once a collection of pus is identified from a prior CT scan, it is mandatory to drain the pus to avoid getting worse. The patient is usually not asked to eat for 4-6 hrs before the procedure and refrain from taking any blood thinning medications. Blood work Is done to ensure that the kidney function is normal. For those with allergies to the dye, the drainage can be done under ultrasound guidance. The procedure is always done in a radiology department.
What happens during the procedure?
You will be asked to lie down and the area of the abscess collection will be marked on the skin. Ultrasound or Ct scan will be done to confirm he presence and location of the abscess. Following this, the skin area will be cleaned with an antibiotic solution and the area will be covered with sterile drapes. Following this a needle will be directed towards the abscess pocket under x ray guidance. The puss will then be aspirated and drained out. If the abscess is re accumulating or large, then the radiologist will leave a small piece of plastic tube (drain) so that all the pus will drain over the next few days. After the procedure the drain is secured to the skin and clean dressing are placed. The total time for drainage of abscess can vary from 30-60 minutes. All fluid collected is sent to the laboratory for analysis for bacteria and other organisms to determine the cause of the pus.
How does one feel after the procedure?
Once the abscess is drained, most individuals recover very fast. Another Ct scan or ultrasound will be done later to confirm that there is no more collection. Or if the patient starts to improve and has no fever or pain, than he/she may be discharged. The drain is usually removed if there is not more pus collection.
How is the drainage catheter maintained?
The catheter remains in the abscess cavity and exits through the patient's skin usually into the abdominal wall where it is connected to free drainage. The patient is asked to observe carefully the catheter to ensure that is does not displaced although this rarely happens. Once drainage from the catheter reduces to a minimum confirmation of resolution of abscess with subsequent image will follow, followed by the removal of the catheter itself.
What are the complications of CT guided drainage?
Usually CT guided drainage is infinitely safer than surgery. However, anytime pus is drained there is a chance of infection of the skin. Today, with finer needles and better localization of pus cavities, the complications of CT guided drainage are minimal. Most common complications include:
- pain at the site
- collapse of lung
- perforation of bowel
However, with sophisticated imaging equipment and appropriate expertise these risks are very small and the benefits of percutaneous drainage of abscess cavities significantly outweigh any risk of complication.
When can I get the results?
In most cases the results of drainage are obvious. Most individual rapidly improve once the abscess is removed. Symptoms such as fever, fast heart rate, pain will all disappear once the pus is removed. The results of the cultures from the pus usually take 5-10 days.
What are the advantages vs disadvantages of CT guided drainage?
- CT guided drainage is less invasive then surgery
- It can help prevent unnecessary surgery
- There is only need for local anesthesia
- Is a useful tool in sick patients who may not be candidates for surgery
- Can access sites which may be difficult with surgery
- Can be done as an out patient procedure
- Is much cheaper than surgery
With any technique where needles are inserted in the body, risks can be expected and these include:
What are the limitations of CT guided drainage?
In some cases the abscess may be located in an area where CT guided drainage may be too risky.
CT guided drainage is not appropriate for abscess collections which are not localized.
For those individual who have blood disorders, CT guided biopsy may be very risky.
Alternatives to CT drainage may include continued follow-up with ultrasound imaging and surgical removal of the abscess.
By ScanDirectory.com Staff
Updated: July 20, 2007