Emergency IR · IR Playbook

Transarterial Embolization for Gastrointestinal Hemorrhage (TAE)

Transarterial embolization controls acute nonvariceal gastrointestinal hemorrhage by selectively occluding the responsible artery after localization with endoscopy, CT angiography or catheter angiography. It is indicated principally for failed or recurrent endoscopic hemostasis and may be used early for hemodynamically significant lower GI bleeding with positive CTA. Current CIRSE data report 89–100% technical success, 70–88% clinical success and 4.5–33% 30-day rebleeding; bowel ischemia is the major concern, particularly after lower GI embolization.

Learning objectives

• Select patients for targeted upper or lower GI embolization and for empiric GDA embolization.
• Relate the bleeding location to the celiac, superior mesenteric or inferior mesenteric arterial territory.
• Apply front-door and back-door occlusion in the collateral-rich upper GI circulation.
• Perform ultraselective lower GI embolization while preserving adjacent bowel perfusion.
• Recognize and manage rebleeding, bowel ischemia and nontarget embolization.

Indications

• Persistent nonvariceal upper GI hemorrhage after failed endoscopic hemostasis.
• Recurrent upper GI hemorrhage after initial endoscopic control when repeat endoscopic treatment is unsuccessful or unsuitable.
• Upper GI arterial hemorrhage when endoscopy is impossible because of altered anatomy, cannot localize or reach the lesion, or is contraindicated.
• Hemobilia, hemosuccus pancreaticus, visceral pseudoaneurysm or postoperative arterial bleeding in which embolization may be the primary treatment.
• Hemodynamically significant lower GI hemorrhage with active extravasation on CTA requiring prompt catheter angiography and possible embolization.
• Persistent or recurrent lower GI hemorrhage that cannot be controlled or localized adequately by colonoscopy.
• Angiographically negative severe upper GI hemorrhage strongly localized by endoscopy or CTA to the GDA or another defined arterial territory.
• Tumor-related, iatrogenic, post-polypectomy, diverticular or angiodysplasia-related arterial hemorrhage when endoscopic control is unsuccessful or unsuitable.

Relative contraindications

• Uncorrectable severe coagulopathy, although NBCA may remain effective because occlusion is less dependent on intrinsic coagulation.
• Severe iodinated-contrast hypersensitivity without an emergency contrast-management plan.
• Acute kidney injury or advanced renal impairment when the clinical benefit does not outweigh contrast-associated risk.
• Previous extensive upper abdominal surgery, radiotherapy or severe mesenteric atherosclerosis that has disrupted protective collateral pathways.
• Inability to catheterize a lower GI bleeding branch sufficiently selectively to avoid extensive bowel devascularization.
• Angiographically negative lower GI bleeding without reliable anatomic localization.

Equipment

• Ultrasound, 18–21 G arterial access needle, 0.018 or 0.035 inch access wire and 4–6 Fr arterial sheath
• 4–5 Fr Cobra, Simmons, SOS Omni, Mikaelsson or other visceral selective catheter
• 1.7–2.8 Fr microcatheter compatible with 0.014–0.018 inch hydrophilic microguidewire
• Power injector with nonionic iodinated contrast and DSA capability
• Detachable or pushable microcoils sized approximately 20–30% larger than the target artery when anchoring is required
• Gelatin sponge pledgets or slurry for temporary occlusion or use between coil packs
• NBCA with iodized oil and dextrose catheter preparation for rapid or coagulation-independent embolization by an experienced operator
• Calibrated 300–500 µm particles for selected hypervascular or diffuse lesions; avoid indiscriminate distal particle embolization
• Vascular closure device or manual-compression equipment
• Snare or retrieval system for selected maldeployed coils

Procedure steps

1. Confirm that resuscitation, blood products and multidisciplinary support are active. Correlate the clinical presentation with endoscopy and CTA to identify the likely arterial territory before entering the angiography suite.Pearl: A positive CTA should lead to prompt angiography because intermittent bleeding may cease before DSA.
2. Access the common femoral artery under ultrasound guidance and insert a 4–6 Fr sheath. Use radial access only when it provides a safe and familiar route without delaying hemorrhage control.Pearl: A stable sheath-catheter platform reduces visceral ostial trauma and facilitates repeated selective angiography.
3. For upper GI bleeding, catheterize the celiac axis and evaluate the left gastric, common hepatic and GDA territories; include the SMA when duodenal or pancreaticoduodenal supply is possible. For lower GI bleeding, select the SMA or IMA according to CTA localization.
4. Acquire selective DSA through the venous phase and look for luminal extravasation, pseudoaneurysm, abrupt vessel cutoff, irregularity, arteriovenous shunting or focal hypervascularity. Repeat or increase selectivity when motion, vasospasm or intermittent bleeding limits the first acquisition.Pearl: Continue imaging into the venous phase to distinguish true persistent extravasation from transient vascular or venous opacification.
5. Advance a 1.7–2.8 Fr microcatheter coaxially into the bleeding branch. For lower GI bleeding, reach the responsible vasa recta or the shortest safely embolizable segment while confirming that the catheter has not induced flow-limiting spasm.Pearl: A small test injection should confirm position, collateral pathways and the amount of bowel supplied before embolic delivery.
6. Select the agent according to vessel caliber, flow, catheter position, collateral anatomy and coagulation status. Coils provide precise focal occlusion; gelatin sponge can supplement coil occlusion, while NBCA provides rapid distal and proximal occlusion that is less dependent on coagulation but requires specific expertise.Pearl: Individualize the NBCA-to-iodized-oil mixture to flow and catheter-to-target distance; greater iodized-oil dilution slows polymerization and increases distal penetration.
7. For a focal upper GI arterial lesion, occlude the culprit branch and assess potential collateral inflow. When the lesion lies in a collateral arcade, embolize both distal and proximal to the bleeding point to close the back door and front door.Pearl: Upper GI rebleeding commonly reflects failure to exclude collateral inflow rather than failure of the initial coil pack.
8. Deliver microcoils or a carefully controlled liquid embolic as close as possible to the bleeding vasa recta. Restrict embolization to the smallest vascular territory that stops hemorrhage and confirm preservation of adjacent bowel branches.Pearl: The objective is ultraselective hemostasis, not angiographic pruning of the surrounding mesenteric circulation.
9. When angiography is negative but failed endoscopy or CTA strongly localizes severe bleeding to a duodenal ulcer or GDA territory, use the endoscopic clip or anatomic landmark to guide embolization. Occlude the GDA across the suspected bleeding level using a distal-to-proximal sandwich technique, commonly with coils with or without gelatin sponge.Pearl: Empiric GDA embolization is an upper GI strategy supported by reliable localization; it should not be extrapolated routinely to angiographically negative lower GI bleeding.
10. After GDA or pancreaticoduodenal embolization, repeat angiography from both the celiac and SMA sides when relevant. Superselect and treat any residual collateral branch that continues to opacify the bleeding site.Pearl: The completion SMA angiogram is essential after GDA sandwich embolization because it can demonstrate otherwise occult back-door bleeding.
11. Document cessation of extravasation, exclusion of any pseudoaneurysm and absence of significant collateral refilling. Confirm preserved flow to uninvolved hepatic, splenic, mesenteric and bowel branches and exclude catheter-related dissection.
12. Remove the arterial sheath when coagulation and hemodynamic status permit, using manual compression or an appropriate closure device. Provide explicit instructions for monitoring recurrent bleeding, abdominal pain, lactate, hemoglobin, renal function and the access site.

Complications

• Recurrent gastrointestinal hemorrhage, 4.5–33% at 30 days
• Bowel ischemia, infarction or perforation
• Nontarget embolization
• Duodenal ischemia or delayed stricture
• Pancreatic or hepatic ischemic injury
• Access-site hematoma
• Visceral arterial spasm or dissection
• Contrast-associated acute kidney injury or severe contrast reaction

Exam pearls

• Upper GI: control both front door and back door; lower GI: embolize as selectively as possible.
• A negative angiogram does not exclude active GI hemorrhage because bleeding is frequently intermittent.
• A positive CTA in hemodynamically significant lower GI bleeding should prompt rapid referral for angiography and possible embolization.
• Empiric GDA embolization is reasonable after failed endoscopy when the source is strongly localized, but routine empiric lower GI embolization is not established.
• After GDA embolization, always consider an SMA angiogram for pancreaticoduodenal back-door supply.
• Packing only a pseudoaneurysm sac is unreliable when collateral inflow persists; exclude the parent arterial segment when anatomy permits.
• Coils provide precision, whereas NBCA provides rapid coagulation-independent occlusion but carries greater technical risk.

Viva questions

When is transarterial embolization indicated in upper GI bleeding?

TAE is principally indicated when nonvariceal upper GI bleeding persists or recurs despite endoscopic therapy, or when endoscopy is impossible or unsuitable. Arterial hemobilia, hemosuccus pancreaticus and visceral pseudoaneurysm may proceed directly to embolization.

What is empiric GDA embolization?

It is embolization of the GDA despite absent angiographic extravasation when endoscopy or CTA strongly localizes severe bleeding to a duodenal ulcer or GDA territory. Reliable localization is essential because empiric embolization is not simply treatment of any angiographically negative GI bleed.

What is the sandwich technique?

The culprit artery is occluded distal and proximal to the bleeding point, closing both the back door and front door. It is particularly important in the GDA and pancreaticoduodenal arcade because SMA collaterals can maintain hemorrhage after proximal-only embolization.

Why must the SMA be checked after GDA embolization?

The inferior pancreaticoduodenal arteries arise from the SMA and communicate with superior pancreaticoduodenal branches of the GDA. SMA angiography can therefore reveal back-door collateral filling or persistent bleeding after celiac-side embolization.

How does lower GI embolization differ technically from upper GI embolization?

Lower GI embolization should be ultraselective, preferably at the responsible vasa recta, because colonic collateral supply is less forgiving. Upper GI embolization more often requires occlusion of both sides of the lesion because the stomach and duodenum have extensive collaterals.

Which embolic is useful in severe coagulopathy?

NBCA is useful because polymerization and vessel occlusion are less dependent on the patient's coagulation system. It provides rapid hemostasis but demands expertise to prevent reflux, catheter adhesion and nontarget ischemia.

What is the most feared complication of lower GI embolization?

Bowel ischemia progressing to infarction or perforation is the principal concern. Risk is reduced by superselective catheterization, limiting the embolized territory and avoiding uncontrolled distal delivery.

What defines technical success?

Technical success requires cessation of extravasation or exclusion of the pseudoaneurysm with no relevant collateral refilling. It also requires preservation of uninvolved bowel and visceral arterial perfusion.

References