Fixation and protective components for use with implantable medical devices, such as access ports and catheters, are disclosed. In one embodiment, a protective sleeve is employed about a catheter so as to distribute compressive loads and ensure patency of the catheter lumen, even in areas prone to pinch-off. A catheter assembly in one embodiment thus comprises an elongate catheter tube that defines at least one lumen. A protective mesh sleeve is disposed about an external portion of the catheter tube so as to cover at least a portion of the longitudinal length of the catheter tube. The protective sleeve is configured to distribute a compressive load on the catheter tube so as to ensure patency of the at least one lumen of the catheter tube.