NEW YORK (Reuters Health) - In the absence of a congenital anomaly, the main cause of inferior vena cava (IVC) thrombosis is the presence of an unretrieved IVC filter, researchers report.
"Since IVC filter thrombosis is the main etiology for IVC thrombosis, physicians may want to ensure the absolute need for the filter before its placement," Dr. Mohamad Alkhouli from University of Rochester Medical Center, New York told Reuters Health by email. "A tracking system should be instituted to follow up with these patients, and the implanted IVC filter should be pulled out as soon as is safe and reasonable."
IVC thrombosis accompanies lower extremity deep vein thrombosis (DVT) in 4% or more of patients, leading to post-thrombotic syndrome (PTS) in up to 90% of patients, disabling venous claudication in 45%, pulmonary embolism in 30%, and venous ulceration in 15%, according to Dr. Alkhouli and colleagues, who reviewed the diagnosis and management of IVC thrombosis in a report online March 9th in JACC: Cardiovascular Interventions.
IVC filter placement rates are 25 times higher in the U.S. than in Europe, and late filter thrombosis has been reported in up to a third of patients, yet retrieval rates are consistently low.
Presenting symptoms of IVC thrombosis include leg heaviness, pain, swelling, and cramping, often preceded by nonspecific back and abdominal/pelvic pain. Because of the ambiguous symptoms and insidious onset, IVC thrombosis often goes undiagnosed until clot migration or embolization into the lungs and renal veins results in dyspnea and oliguria.
Lower extremity duplex ultrasound can be used to screen for IVC thrombosis, but appropriately timed CT and MRI are essential for diagnosis and assessment of the extent of thrombosis.
Once IVC thrombosis is diagnosed, the mainstay of treatment is anticoagulation, although specific guidelines are lacking.
In observational studies, thrombus removal with pharmacomechanical catheter directed thrombolysis (PMCT) has reduced the incidence of PTS and improved quality of life, but whether this is as safe as standard anticoagulation remains unclear.
While acute thrombosis may be amenable to PMCT and catheter-directed thrombolysis (CDT), the presence of a fibrotic component in patients who present late may require balloon venoplasty with or without stenting.
The available treatments work best when IVC thrombosis is recognized early, Dr. Alkhouli said.
Dr. Michael Jaff from Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, who wrote an editorial related to this report, told Reuters Health by email, "Limit placement of IVC filters to only absolute indications, and retrieve them as soon as possible."
Dr. Jaff explained, "There are three basic questions I ask myself when considering catheter-based intervention for IVC thrombosis: (1) How long has the patient had symptoms/signs suggestive of this, and how severe are they? (2) What is my estimation of bleeding risk? (3) Do I have an interventionist with skill and experience available to perform the intervention?"
He continued, "Regarding question 1, shorter duration of symptoms and more severe symptoms and signs prompt me to aggressively consider catheter-based intervention. Regarding question 2, if there is significant bleeding risk (for example, inflammatory bowel disease as the underlying culprit for the IVC thrombosis), I am reluctant to consider catheter-based intervention.Regarding question 3, don't consider this if your colleague has little experience performing this procedure or managing the complications of the procedure."
Dr. Xiao-Qiang Li from Second Affiliated Hospital of Soochow University in Suzhou, China, who recently described the experience with CDT combined with manual aspiration thrombectomy for acute inferior vena cava filter thrombosis, told Reuters Health by email, "As you see, no consensuses have been reached."
"For a new patient with acute DVT, if he or she has no contraindications for thrombolysis, especially with a life expectancy more than one year, we prefer to perform catheter-based interventions, including catheter-directed thrombolysis, pharmacomechanical thrombolysis, ultrasound-assisted catheter-directed thrombolysis and subsequent percutaneous transluminal angioplasty and stenting,"Dr. Li said."But, of note, anticoagulation is the basic treatment whatever catheter-based interventions are adopted."