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218 PART 2: General Management of the Patient

our hospital, patients are evaluated on a case-by-case basis and GASTROINTESTINAL BLEEDING
occasionally, infusion dosage is decreased if levels fall dramatically
(ie, <100 mg/dL).
KEY POINTS
Increasing Leg Pain: Increasing pain is common during arterial throm-
bolysis. The term “storm before the calm” has been coined to explain • All mesenteric angiograms done for intestinal bleeding are done
this phenomenon. This often indicates progressive thrombolysis with with the intention to treat.
proximal clot regressing and migrating distally. Nonetheless, the limb • Upper gastrointestinal bleeding should be first triaged and treated
should be examined for motor and sensory loss and the possibility with upper endoscopic methods. Refractory cases of arterial bleed-
of reperfusion injury (eg, compartment syndrome) should always be ing should be embolized in interventional radiology; refractory
considered. For pain control, morphine 5-mg intravenous is adminis- cases of variceal bleeding should be treated with transjugular por-
tered every 1 to 2 hours as needed. tosystemic shunting or balloon-occluded transvenous obliteration.
End Points: There are four possible end points to thrombolytic infusion. • Lower gastrointestinal bleeding should be triaged with either
nuclear scintigraphy (tagged red blood cell study) or CTA prior to
1. Reestablishing flow in the graft or vessel with complete clot dissolu- angiography.
tion or reestablishing baseline condition.
2. Thrombolytic stagnation: no change in angiogram with continued
thrombus over 2 or 3 incremental angiograms. Gastrointestinal bleeding (GIB) can be categorized as arising from either
3. Complication: remote bleeding, compartment syndrome, irrevers- the upper or lower GI tract. Upper GIB is further subdivided into arterial
ible ischemia. (nonvariceal) and venous (variceal) etiologies. These are important points
4. Maximal dose: generally considered to be 40 mg with catheter of differentiation as they affect the preangiographic workup and determine
directed infusion therapy although this is not a firm limit. If throm- what endovascular procedures may be required. Active arterial bleeding
bolysis is progressing and the patient is improving, the infusion may diagnosed with arteriography is treated with embolization, whereas venous
be continued at the physician’s discretion. bleeding may require either a transjugular intrahepatic portosystemic shunt
■ RESULTS AND COMPLICATIONS of gastric varices. The following discussion will focus on arterial GIB.
placement or possibly balloon-occluded transvenous obliteration (BRTO)
patients with lower extremity pain and suspected acute limb threaten- ■ INDICATIONS AND PATIENT SELECTION
Recently CTA and MRA have been used more liberally to evaluate
ing ischemia. Cross-sectional imaging is helpful to help triage patients Upper GI Bleeding: After medical stabilization, upper gastrointesti-
who may benefit from catheter-directed thrombolysis and helps the nal bleeding should first be evaluated and managed by endoscopy
interventional radiologist to plan the intervention. These noninvasive because bleeding can be both diagnosed and treated concurrently.
imaging techniques can also help differentiate in-situ thrombosis from Interventional radiologic techniques are used in patients with refractory
peripheral embolization in some patients. bleeding. If bleeding cannot be localized on endoscopy, either nuclear
Many interventionalists combine mechanical and pharmacologic scintigraphy or CTA (discussed below) may be beneficial.
thrombolysis. The general strategy is to “debulk” clot with mechanical Currently, most IRs perform mesenteric angiography in a bleeding
devices then “clean up” the residual clot using pharmacologic thrombo lysis. patient with intention to treat. In upper GI bleeding, the site of bleed-
We employ this strategy most commonly for deep venous thrombo- ing identified on endoscopy will direct embolization. Bleeding in the
lysis where infusions are commonly protracted and clot burdens are proximal stomach and fundus is treated by embolizing the left gastric
larger. The cost effectiveness of this strategy is unclear and is currently artery; bleeding in the antrum or duodenum is treated by embolizing
undergoing further investigation. the gastroduodenal artery (GDA) (Fig. 30-12). If the site of bleeding is
There have been three large randomized trials comparing thromboly- able to be localized by endoscopy, embolization will often be performed,
sis with surgical therapy. 25-27 Overall, the mortality and limb salvage out- irrespective of whether or not active extravasation is documented angio-
comes are similar although there are higher rates of bleeding and distal graphically. This is termed empiric embolization and is widely accepted
embolization when thrombolysis is pursued. The risk of complications and the standard of care in many institutions.
increases with duration of infusion. In general, thrombolysis is deemed
appropriate for acute (<14 days) thrombotic or embolic occlusions and Lower GI Bleeding: Lower GI bleeding is typically more difficult to
less effective for chronic occlusions. diagnose and treat endoscopically compared to upper GI hemorrhage.
The rationale for deep venous thrombolysis is that early removal Many endoscopists are reluctant to perform endoscopy in the actively
of clot can prevent short- and long-term adverse sequelae in appro- bleeding patient without bowel purge, especially if bleeding is brisk. If
priate patients. The postthrombotic syndrome may occur in 50% of the bleeding site cannot be identified endoscopically or if the source of
patients treated with anticoagulation and compression stockings and bleeding cannot be controlled, interventional radiology consultation
is caused by damage to venous valves in the leg. Patients that develop is warranted. Surgery is generally considered the last option, although
this syndrome have edema and skin changes in the affected leg(s). In endovascular intervention can be considered following failed surgery.
severe cases, venous ulcers occur. Available evidence suggests that early Localization of bleeding is strongly preferred before attempting
removal of clot may preclude postthrombotic syndrome. The National endovascular therapy of lower gastrointestinal bleeding for several rea-
Institutes of Health has sponsored the first ongoing multicenter phase III sons. First and foremost, embolotherapy is predicated on the ability to
randomized controlled trial called the ATTRACT (acute venous visualize the offending lesion. If the site of bleeding cannot be identified
thrombosis: thrombus removal with adjunctive catheter-directed by nuclear scintigraphy or CTA (see discussion below), it is unlikely to
thrombolysis) trial to compare thrombolysis and anti-coagulation to anti- be found at conventional angiography and consequently embolization
coagulation alone in patients with symptomatic proximal lower extrem- cannot be performed. Secondly, endovascular interventions have been
ity deep venous thrombosis. The American College of Chest Physicians shown to be more successful when GIB is confirmed and localized.
29
recommends use of thrombolysis in patients with extensive acute Third, when bleeding is localized, it decreases procedure time by allow-
(<14 days) iliofemoral deep venous thrombosis, good functional status, ing for a more targeted approach. This consequently reduces radiation
and a life expectancy of greater than 1 year who have a low bleeding risk. exposure to both patient and physicians and the amount of contrast
Correction of underlying venous lesions using angioplasty and stents is material used during angiography. Minimizing contrast dose is critical
also recommended. 28 in patients with borderline azotemia. Finally, conventional angiography,

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