Patients with long term indwelling central catheters can develop sleeve thrombus or an associated fibrin sheath
that could theoretically cause physical trapping of FDG [1, 8].
Skin flora migrates along the dermal tunnel and settles in the fibrin sheath
that forms in 3 days around the intravascular portion of the catheter.
Upon valve actuation for treatment, fibrin sheath
formation is disrupted, lumens are thrombus free, and high flow rate hemodialysis can be freely delivered.
The other two reasons of catheter failure are thrombosis and fibrin sheath
formation around the catheters.
There is a myriad of causes of catheter dysfunction, including patient positioning, mechanical kinking, malpositioning of the tip out of the right atrium, leakage, drug precipitation, thrombus accumulation, and growth of a fibrin sheath (Chan, 2008).
Similarly, Falk (2008) states that once a peri-catheter thrombus or fibrin sheath occurs, the patient is predisposed to infection; similarly, pericatheter infection increases the risk of thrombosis.
thrombus--forms when fibrin adheres to the external surface of the catheter, creating a "sock" over the end of the catheter.
The distal tip of the LifeJet(TM) F-16 catheter has been specially designed to help resist fibrin sheath
formation, a common and costly complication associated with conventional hemodialysis catheters.
The common thrombotic complications include fibrin sheath
obstruction, subclavian vein thrombosis (SCVT), and superior vena cava thrombosis (SVCT).
* Thrombus accumulation within one or both lumens: the growth of a fibrin sheath
over part or all of the exterior of the catheter; or a mural thrombus that changes the flow dynamic in the vessel and therefore the catheter.
Poorly placed catheters are repositioned, while fibrin sheaths
and thrombi are cleared by invasive mechanical methods, such as fibrin sheath
stripping, or with thrombolytic therapy.
Thrombotic occlusions occur as intraluminal clots, fibrin sheaths
or tails, or thrombi in the venous walls of the vessels (Herbst, Kaplan, & McKinnon, 1998)(see Figure 1).