Abscess Drainage
What is an abscess and how is it treated?
An abscess is a collection of infected fluid, or pus, within the body. It can occur in any part of the body. Antibiotics often effective to treat the infection, but drainage of the abscess may also be necessary.
Abscess drainage was traditionally accomplished with surgical placement of a drainage tube. Today, surgery is usually not necessary because of advances in image-guided drain placement. Interventional radiologists perform image guided abscess drainage, using CT scanning, ultrasound, or fluoroscopy to “see” inside the body during the procedure.
What are the risks?
Image guidance not only guides placement of an abscess drainage tube, but it also avoids inadvertent injury to normal structures that are deep within the body such as major arteries or veins, organs, and bowel. Nevertheless, there is a small risk of bleeding or organ injury despite the most careful drain placement.
There is also a small risk that the drainage procedure will initially make the symptoms of infection worse simply by drain placement. Fevers and chills may follow drainage, but tend to resolve within a few hours.
Intravenous radiographic contrast material may be used during CT scanning immediately before abscess drainage, and there is a very small chance of contrast-related allergy. Most of these allergies are mild, but very there may be shortness of breath or even increased or decreased blood pressure. There is also the small risk that kidney function will be impaired in patients who already have impaired kidneys. Before administration of radiographic contrast, blood tests are performed to evaluate kidney function. A number of medicines as well as fluids are used to help prevent or relieve most of the allergic and kidney effects of radiographic contrast.
Reasons to avoid this procedure
Depending on the location of the abscess, it may not be safe to peform image-guided abscess drainage. For example, if there isn’t a safe way to place the drain because of overlying normal organs, bowel, or blood vessels, the procedure will be aborted. Your interventional radiologists will review all of your scans before the procedure and do a preliminary scan before starting the drain placement to be sure that safe drain placement is possible. Even when there is a safe way to drain an abscess, in some cases the abscess will be too small (<2cm) for drainage, and most of these small abscesses will resolve with antibiotics, alone.
How the procedure is done?
The procedure is performed in the radiology department. An entire team will be taking care of you during the procedure including a radiology nurse, a radiography technologist, and the physician. Your breathing, blood oxygen, blood pressure, and heart rate will be monitored throughout the procedure. You will be given intravenous medications for pain relief and to treat anxiety. If necessary, the procedure area will be shaved. The skin will then be sterilized with a special liquid, covered with sterile drapes, and the skin will be locally anesthetized with an injection of Lidocaine. This injection may cause some burning but shortly thereafter the area will be numb. Then, image-guided insertion of the abscess drain will be performed.
Once the abscess drain is confirmed to be in good position, the abscess will be drained. More than one drain may be necessary to achieve complete abscess drainage or treatment of more than one abscess. Typically, the drains have a curl at the tip that helps prevent dislodgment. Nevertheless, we typically place a small suture at the skin to help secure the catheter. Then, a gauze dressing is applied at the drain insertion site. We recommend keeping this dressing dry for the first two weeks, but if it gets wet, simply blot it dry with a towel. If the gauze becomes wet, the entire dressing should be changed.
What you can expect after the procedure?
Immediately after the procedure you will be able to drink fluids and see your family members, though only 1-2 family members can stay with you in the post procedure area. Your diet will be advanced to a regular diet as soon as possible, though some abscesses are caused by infection of the bowel, in which case your diet may be limited to fluids until the bowel heals.
It is likely that you will stay in the hospital after the procedure for ongoing abscess drainage, antibiotics, and general care. Once you no longer have signs of active infection you will be discharged home, usually with the abscess drain still in place (see below for information about home care of the drain). You will need to continue to take antibiotics for a minimum of 7-10days after the procedure.
The drain will stay in place for at least 48 hours and may be necessary for several weeks. The drain can be removed when the drainage is minimal for two consecutive days. If you are discharged with the drain, you should call the interventional radiology department at 650-404-8445 to make an appointment for follow up and possible drain removal.
How long does it take to recover?
The recovery time is variable and will depend on how severe the infection is. Most patients should be able to return to their normal activities 1 week after the procedure.
We recommend no contact sports or strenuous activity while you have the drain, and for a period of approximately 1 week after removal of the drain to minimize the chance of bleeding.
What should I watch for?
You may be sore after the procedure. However, the pain should not be getting worse and should subside in 2-3 days. If you develop severe pain or if there is substantial bleeding you should seek immediate medical attention at your closest emergency room. If pain seems to be getting gradually worse, if you develop new fevers or chills, or if the drain becomes dislodged, you can call us at (650) 404-8445 Monday thru Friday between 8am-5pm, or reach the on-call Interventional Radiologist by calling (408) 739-6000.
Home care of your catheter
The important aspects of home catheter care are summarized in “My drainage Catheter.” Essentially, you should be sure the catheter is draining, and for some people we recommend daily flushing of the catheter with a syringe. If there is a suction bulb, it should be properly set up to apply suction. Daily drainage and your daily temperature need to be recorded. This daily recording should be brought with you to your clinic visit. You should call (650) 404-8445 when you are discharged from the hospital to arrange this clinic visit.