Chapter 11 Intensive Care Unit

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CHAPTER 11 • Intensive Care Unit Imaging

of interest with lower total anticoagulant doses while avoiding unneeded systemic overlap with its attendant risk. Lower doses avert an unacceptable bleeding risk. (Patients should not simultaneously receive a thrombo- lytic infusion and full dose anticoagulation.) Catheter- directed infusion therapy is a strong consideration for iliofemoral and caval venous clots as well as for life- threatening and symptomatic pulmonary emboli. The same strategy can be successfully applied to arterial occlusions occurring in circumstances of peripheral vascular disease or embolic, traumatic and iatrogenic compromise of extremities, mesentery, or brain. Percutaneous thrombectomy devices are diver- sifying and proliferating as their indications for use expand at a very rapid rate. Most devices rely on a suction removal mechanism with or without mac- eration. Such percutaneous procedures carry less morbidity risk than the more complex surgical inter- ventions with which they compete (see Chapter 23). Vascular Access As critically ill patients often present challenges to achieve bedside vascular access (e.g., massive obesity, vasculopathy, recurrent instances of ICU care), the IR service is become highly valued for this purpose alone. IR practitioners are facile with US-guided cannula placement of central lines, cooling catheters, hemodialysis catheters, ports, and tunneled central venous lines. Misplaced cath- eters can also be repositioned with relative ease (Fig. 11-30). Arterial line access can usually be attained with relative ease.

Coils

Stent

FIGURE 11-29. Two useful endovascular interventions for cerebral aneurysm repair: stenting and aneurysm oblitera- tion by coils and clot.

such as arteriovenous malformations and aneurysms. Small cerebral aneurysms may be coiled, and when timing and risk profiles are appropriate, carotid and intracerebral vascular stents may be considered to improve jeopardized perfusion of zones with critically compromised blood flow (Fig. 11-29). Catheter-directed thrombolysis and/or percuta- neous thrombectomy has gained increasing traction since the introduction of sophisticated implements and safer drugs and dosing regimens for infusion. Full-intensity treatment can be directed to the point

FIGURE 11-30. Catheter inserted via left internal jugular vein could not be inserted into proper position for best function and safety (left) . Fluoroscopic placement by IR repositioned the catheter to intended site (right) . Arrows indicate catheter tip.