Interventional Radiology in the Management of Visceral Artery Pseudoaneurysms: A Review of Techniques and Embolic Materials

Abstract

Visceral artery pseudoaneurysms occur mostly as a result of inflammation and trauma. Owing to high risk of rupture, they require early treatment to prevent lethal complications. Knowledge of the various approaches of embolization of pseudoaneurysms and different embolic materials used in the management of visceral artery pseudoaneurysms is essential for successful and safe embolization. We review and illustrate the endovascular, percutaneous and endoscopic ultrasound techniques used in the treatment of visceral artery pseudoaneurysm and briefly discuss the embolic materials and their benefits and risks.

Keywords: Embolic agent; Endovascular embolization; Interventional radiology; Pseudoaneurysm; Visceral artery.

Fig. 1. Schematic diagram of differences between true aneurysm and pseudoaneurysm.

Fig. 2. 33-year-old male with confirmed chronic pancreatitis, presenting with high grade fever and hematemesis.

Transabdominal ultrasonographic images of right hepatic artery pseudoaneurysm (arrows) showing well defined anechoic lesion on grey scale image (A) with characteristic "yin-yang" sign on color Doppler (B). Cholangitic abscesses are seen adjacent to pseudoaneurysm (arrowheads).

Fig. 3. CT angiography in 38-year-old male with acute pancreatitis and melena.

Axial images in arterial (A) and venous (B) phases show small pseudoaneurysm arising from splenic artery (arrows) with pancreatic inflammation. Maximum intensity projections in axial (C) and coronal (D) planes and three-dimensional volume rendered image (E) better demonstrate characteristics of pseudoaneurysm (arrows).

Fig. 4. Sac packing. 42-year-old male patient with acute pancreatitis, presenting with hematemesis and hemodynamic instability.

DSA image showing short necked pseudoaneurysm (arrows) arising from gastroduodenal artery (A, B), which was subsequently packed with microcoils and embolized (C). Sac packing was made possible due to origin from branch of gastroduodenal artery, narrow neck, and ability to enter pseudoaneurysm with microcatheter. Schematic diagram of sac packing (D). DSA = digital subtraction angiography

Fig. 5. Sandwich technique. 36-year-old male patient with chronic pancreatitis, presenting with upper gastrointestinal bleed.

A, B. DSA images showing pseudoaneurysm arising from gastroduodenal artery (arrowheads in A), which was embolized with coils occluding back door and front door (arrows in B). Sandwich technique was used, since pseudoaneurysm arose from main trunk of gastroduodenal artery, which has collateral supply. C. Schematic diagram of same. DSA = digital subtraction angiography

Fig. 6. Proximal occlusion. 30-year-old male presenting with hematuria and hypotension after percutaneous nephrolithotomy.

A. DSA image showing pseudoaneurysm (arrow) arising from lower pole branch of renal artery. B. DSA image after embolization with proximal coil placement (arrow). As renal arteries are end arteries, proximal occlusion is sufficient to treat pseudoaneurysm. C. Schematic diagram of proximal delivery. DSA = digital subtraction angiography

Fig. 7. 26-year-old male patient with chronic pancreatitis, presenting with recurrent melena.

A. DSA image showing left gastric artery pseudoaneurysm (arrow). Glue-lipiodol mixture was used to embolize pseudoaneurysm and post embolization DSA image (B) shows glue cast (arrowhead). Coil placed in previous gastroduodenal artery pseudoaneurysm is also seen (block arrow). As pseudoaneurysm arose from close to celiac artery division, coil would have protruded proximally. Glue was used to fill pseudoaneurysm successfully. DSA = digital subtraction angiography

Fig. 8. Other techniques: schematic diagram illustrating stent graft placement (A), stent assisted coiling (B), and balloon remodelling (C) techniques.

PsA = pseudoaneurysm

Fig. 9. Percutaneous approach for pseudoaneurysm embolization. 34-year-old female patient with pancreatitis, presenting with hemodynamic instability. DSA showed spastic splenic artery, which could not be catheterized.

A. Schematic illustration. B. Axial CTA image showing PsA arising from tortuous splenic artery (arrow). C, D. Ultrasonographic images showing anechoic PsA with color filling on Doppler image (arrow). E. Ultrasonography image after percutaneous embolization with glue showing thrombosis of PsA (arrow). CTA = CT angiography, DSA = digital subtraction angiography, PsA = pseudoaneurysm

Fig. 10. EUS guided thrombin injection. 27-year-old male patient with pancreatitis, presenting with hematemesis. DSA and ultrasonography did not demonstrate pseudoaneurysm.

A. Schematic diagram. B. Axial CT image in venous phase showing pseudoaneurysm (arrow) within pancreas. C. EUS with color Doppler showing pseudoaneurysm with peripheral thrombus (arrows). D. Needle placed in pseudoaneurysm under EUS guidance prior to thrombin injection. E. EUS image showing thrombosed pseudoaneurysm after thrombin injection (arrows). A = artery, DSA = digital subtraction angiography, EUS = endoscopic ultrasonography, PsA = pseudoaneurysm

Fig. 11. Complications of embolization.

A. Coil embolization of pseudoaneurysm (arrow) with distal migration (arrowhead) into gastroepiploic artery due to undersize of coil. B. Oversized coil resulting in its straight deployment in inflow artery (arrowheads). Arrow shows splenic artery pseudoaneurysm. C, D. Gastroduodenal artery pseudoaneurysm (arrow) with dissection (arrowhead). E, F. Rupture of renal artery pseudoaneurysm (arrow) with extravascular perinephric leakage of contrast (arrowheads). G. Non-target embolization due to reflux of glue (arrowheads) into splenic artery branches. Arrow points to splenic artery pseudoaneurysm. A = artery, GDA = gastroduodenal artery, PsA = pseudoaneurysm

Fig. 12. Algorithm for management of visceral artery pseudoaneurysms.

EUS = endoscopic ultrasonography, USG = ultrasonography