Percutaneous aspiration or drainage of body fluids. Ken U. Ekechukwu, MD, MPH, FACP.

What are body fluids?
Blood is body fluid, but a natural one and so is cerebrospinal fluid which baths the brain and the spinal cord. There are, however, times when ill-health in specific parts of the body induce the formation of abnormal collections of fluid, which if not diagnosed and drained will cause more problems. Abscesses from infections, ascites from a failed liver, heart, or kidney, and hydrothorax from a lung infection, lung cancer, or heart failure are a few of such instances. Commonly, your health care provider decides when a body fluid needs to sampled for diagnosis or drained for treatment. What is percutaneous aspiration or drainage? There was a time in the history of medicine when the removal of most serious body fluids like abscesses required a surgeon’s knife and a large gaping wound thereafter that took several weeks to heal and left an ugly scar. Such occasions are now rare, at least in the western hemisphere. This is because interventional radiologists, guided by using such things as fluoroscopy (x-rays), ultrasound, and CT scan can easily ‘see’ and remove these fluids, usually by passing small tubes called drainage catheters through small cuts (less than 2 mm wide) they make in the skin. Per (through) cutaneous (derived from cutis which means skin) drainage (removal or evacuation) of body fluid, therefore, means draining or removing a body fluid through a skin incision.

What is the preparation for percutaneous imaging-guided aspiration/drainage?
First, you or a designee must ask of and receive from your care provider an account of the merits and demerits of this procedure and its alternatives. When you have done this, you must endorse the procedure by appending your signature on a document called a consent form. A few more details:
1. Understand that this is not major surgery.
2. You will be checked for abnormalities of your clotting system to prevent bleeding complications.
3. Many interventional radiologists perform this procedure with local anesthetics only; you may not need to starve before the procedure.
4. Understand that some body fluids resolve slowly, which means that you may be required to wear the drainage catheter hanging down your side for a short period of time.
5. You may be required to flush the tube periodically if you wear it home. Be sure you clarify this before leaving the hospital or clinic.

How is percutaneous imaging-guided fluid aspiration/drainage done?
If only a small amount of fluid is required for diagnosis, you may have this done as an outpatient procedure, which means you get to go home soon after the procedure. If catheter insertion is necessary, it is usually prudent to remain in the hospital until your provider thinks you can go home. Some infected body fluids require that you receive systemic antibiotic before they are drained to minimize your risk of seeding your blood with the germs responsible for the fluid collection. Usually, previous tests will have determined the location and nature of the body fluid. The operator, after confirming the location of the fluid, will clean the overlying skin with antiseptic agent and isolate it with a sterile drape.

After applying local anesthetic to the skin and the deep tissues, he will make a small skin cut and, through the cut advance a drainage catheter or needle (depending on whether a drainage or aspiration is intended) into the fluid collection. Some body fluids like abscesses can be actively aspirated dry upon catheter insertion, while others, like massive ascites and hydrothorax, are drained more slowly because overzealous and aggressive drainage of such fluids can cause harm. So, whether your fluid will be drained dry upon catheter insertion or allowed to drain slowly will depend on its nature and size.

Thick fluid collections will require periodic flushing of the drainage catheter to dislodge debris that otherwise will clog the holes in the catheters; you or a loved one may have to do this at home.

Who needs imaging-guided aspiration/drainage of body fluid?
• People with large fluid accumulations that cause fever, pain, or discomfort
• Fluid accumulations of unknown cause or source.

What are the contraindications to percutaneous imaging-guided aspiration/drainage of body fluid?
Contraindications are conditions you may have that will make percutaneous fluid drainage hazardous to you. You must let your health care giver know of them before embarking on this procedure. They include:
• Uncorrectable coagulopathy (this means ‘thinning’ of your blood which may make you bleed too much), 
• No safe route (if past surgery or injury left you with scars on and around the drainage site) to the fluid.  How will I care for the tube? It is easy to care for the tube at home by yourself or a loved one. Just remember to flush it regularly (every 6 to 8 hours depending on the thickness and nature of the fluid collection) with sterile water or normal saline. If you are in the hospital your nurses will take care of this for you. How long will I wear the tube and how do I get rid of it when I’m done? Your condition and your health care provider will decide when you will stop wearing the tube. Removing it is easy. You can be taught how to remove it or, when you are done using it, call or visit your care provider at his clinic to remove it. Usually, the hole in the skin seals in 48 hours after removing the tube.