Page 321 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 30: Interventional Radiology 225

■ RESULTS AND COMPLICATIONS a variety of percutaneous methods and in some patients, shunt occlu-

Technical success of TIPS is greater than 90% when the portal vein is sion may be necessary.
patent. TIPS creation in the presence of a thrombosed portal vein has
been reported, but technical success rates are lower. 67,68 Primary shunt INTRAVASCULAR FOREIGN BODY RETRIEVAL
patency at 6 months approximates 75% for bare metal stents, 69,70 but with
the Viatorr™ endoprosthesis, the primary patency rate at 12 months is KEY POINTS
79.9% to 84%. 71,72 Recurrent bleeding after TIPS occurs in 4% to 17% of
patients. The main predictors of mortality after TIPS are poor liver func- • Percutaneous image-guided intravascular foreign body retrieval
tion, urgency, and comorbidities. A 30-day mortality rate of approxi- should be pursued prior to surgical therapy.
mately 15% and a 6-month mortality rate of 30% have been reported. • If foreign bodies are not removed acutely, they may become impos-
The reported 1-year survival rate is 48% to 90% for variceal hemorrhage sible to retrieve later due to endothelialization and incorporation
and 48% to 76% for ascites in the bare stent literature. For Viatorr™ stent into the adjacent vasculature.
shunts, the survival rate is 65% to 88%. The overall mortality rate varies
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by the Child-Pugh classification and patient stability at the time of the
shunt procedure. A series showed the cumulative 30-day survival rates Central venous catheters and IVC filters are among the most common
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for Child-Pugh classes A and B (91%) and class C (71%). These figures medical devices inserted in ICU patients. On occasion, fragmentation
compare very favorably with surgically placed portosystemic shunts in and migration of catheters or filters within the vascular system may
terms of overall morbidity and mortality and the length of postproce- occur, necessitating removal. Endovascular retrieval is the treatment of
dure survival. choice; the alternative, surgery, poses greater risks and requires general
TIPS creation acutely relieves portal hypertension and its complica- anesthesia. Other implantable devices at risk for migration include
tions in the vast majority of patients. Shunt stenosis may occur in up stents, embolization coils, pacemaker leads, and guide wires.
improved long-term patency. Routine surveillance with Doppler US ■ INDICATIONS AND PATIENT SELECTION
to 70% of patients with the bare metal stents but covered stents have
is necessary to identify shunt problems requiring further venographic Catheter fracture and migration can occur at the time of placement or
examination and intervention. TIPS venography and revision can be removal, or may even occur during day-to-day usage. Catheter tips should
performed on an outpatient basis in most cases. routinely be inspected at the time of removal to ensure that the catheter has
Complications of TIPS include shunt dysfunction, neck hema- been removed in its entirety. Because the integrity of the catheter material
toma, liver capsule puncture with or without abdominal hemorrhage, deteriorates with time and usage, the risk of catheter fracture increases with
hemobilia, or worsening liver failure, sepsis, and stent migration. dwell time of the catheter. Catheter fracture can also occur secondary to
Occasionally, patients develop multisystem organ failure with no “pinch-off syndrome” when the catheter is repeatedly compressed between
evident source of sepsis. New or worsening encephalopathy appears the costoclavicular ligaments and first rib leading to fatigue and finally
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to be more common in the era of covered stents, especially in patients breakage (Fig. 30-16). It is important to recognize that this phenomenon
with refractory ascites who often have more advanced liver failure is unique to catheters placed in the subclavian vein. Fragmentation of
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compared to patients with variceal bleeding. Most patients who IVC filter struts is an increasingly common complication that may be
develop encephalopathy after TIPS can be managed medically with related to the increasing use of retrievable filters in lieu of permanent fil-
antibiotics, protein restriction, and lactulose. In patients who are ters and their long dwell times. Intact filters can be complicated by struts
refractory to medical management, shunts can be reduced in size by perforating structures outside the IVC wall. 75

FIGURE 30-16. A. “Pinch-off” phenomenon. Chest radiograph shows subclavian port catheter has fractured and the distal tip has migrated to the right atrium. Incidentally, a second
catheter fragment is present in the coronary vein. B. Fluoroscopic image shows ensnared catheter fragment being removed.

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