Keywords
BRTO - LARTO - liquid-embolic assisted retrograde transvenous obliteration - LAVA
- liquid embolic
The balloon-occluded retrograde transvenous obliteration (BRTO) technique has been
used for over 25 years for the management of gastric varices. Recent advancements
have introduced variations such as coil-assisted retrograde transvenous obliteration
(CARTO) and plug-assisted retrograde transvenous obliteration (PARTO) to reduce procedure
time and improve efficacy. The authors present a novel variation, liquid-embolic assisted
retrograde transvenous obliteration (LARTO), which uses a liquid embolic system (LES)
in place of coils or vascular plugs to achieve durable occlusion during variceal obliteration.
A 76-year-old male with hypertension, hyperlipidemia, and diabetes, but no history
of liver disease, presented to the emergency department with hematemesis and several
days of melena. Contrast-enhanced computed tomography (CT) of the abdomen revealed
cirrhosis with gastric varices without paraesophageal varices, splenomegaly, or ascites
([Fig. 1]). Upper gastrointestinal (GI) endoscopy confirmed the imaging findings of gastric
varices without active hemorrhage, but clot was seen over the varices indicating recent
bleeding. The patient was referred to interventional radiology (IR) for further management
of bleeding gastric varices, per our institutional protocol. Pertinent laboratories
included hemoglobin of 7.7 g/dL, platelet count of 126 × 10^9/L, prothrombin time/international
normalized ratio 11.9/1.14, and Model for End-Stage Liver Disease score of 11. Closer
review of the CT showed a type A shunt (based on venous drainage), with a splenorenal
shunt draining through an enlarged inferior phrenic vein into the left renal vein
and inferior vena cava. The BRTO procedure was performed using a right internal jugular
vein approach and 6 French Ansel 45 cm sheath was placed into the left renal vein.
The outflow vein (draining into the left renal vein) was catheterized using 5 French
C2 catheter and a J-Rosen wire. A balloon-occlusion catheter (Fogarty 5.5 French,
McKesson Corporation, New York City, New York, United States) was deployed occluding
the outflow varix, and venography was performed demonstrating opacification of the
gastric varices ([Fig. 2]). After confirming complete outflow occlusion with balloon-occlusion catheter (evidenced
by no leakage of contrast into the left renal vein), a 2.4-French Progreat microcatheter
(Terumo Corporation, Tokyo, Japan) was advanced distally into the varix. The sclerosant
foam was made using the widely used Tessari method, using 15 mL air, 10 mL of 3% sodium
tetradecyl sulfate, and 5 mL Omnipaque 350 contrast in a 3:2:1 ratio. To provide additional
embolic effect to the sclerosant, the foam was then mixed with Embocube (uniformly
cut gelatin foam, 2.5 mm × 50 mg, Merit Medical, Jordan, Utah, United States). The
sclerosant was injected through the microcatheter into the varices, while constantly
mixing the foam to prevent settling. Intraprocedural cone-beam CT confirmed good sclerosant
distribution within the gastric varices ([Fig. 3]). After the entire sclerosant mix was injected, the microcatheter was removed and
a new 2.4 French Progreat microcatheter was placed into the outflow vein, and primed
with 0.6 mL dimethyl sulfoxide (DMSO). The LAVA liquid embolic (Liquid Embolic for
Vascular Applications; SIR Tex, Woburn, Massachusetts, United States) was slowly injected
to occlude the outflow vein while the microcatheter was retracted to the tip of the
balloon catheter. The LAVA 36 viscosity variant was utilized and a total of 1.1 mL
embolic volume was used. Complete occlusion of the outflow vein was confirmed by slowly
deflating the balloon and absence of contrast leakage into the renal vein. Gentle
contrast injection was performed showing effective occlusion of the outflow vein ([Fig. 4]), and the catheter was removed. The patient was discharged the following day without
recurrent upper GI bleeding. Most recent 6-month follow-up with the gastroenterology
outpatient service showed no recurrent episode of upper GI bleeding. The patient was
ultimately diagnosed with metabolic dysfunction-associated steatotic liver disease.
Fig. 1 (A) Contrast-enhanced axial computed tomography (CT) of the abdomen demonstrates enhancing
collateral vessels in the gastric region (arrow) consistent with varices. Note the nodular margins of the liver indicating cirrhotic
morphology. No ascites, splenomegaly, or periesophageal varices were seen. (B) Coronal 10 mm maximum intensity projection (MIP) reconstruction from the CT showing
the outflow vein (long arrow) and the gastric varices. This was used for procedural planning.
Fig. 2 Right internal jugular vein approach venography with the sheath in the left renal
vein (black arrow), the tip of the balloon-occlusion catheter in the outflow vein (small white arrow), microcatheter beyond the base catheter, and contrast within the gastric varices
(long white arrows).
Fig. 3 Intraprocedural cone-beam computed tomography (CT) after the injection of sclerosant
demonstrates opacification of the varices (arrows) confirming appropriate distribution of the sclerosant.
Fig. 4 Fluoroscopic image after the injection of liquid embolic material into the outflow
vein (arrows) and deflation of the occlusion balloon demonstrating static contrast within the
gastric varices, confirming complete occlusion.
The classic BRTO technique requires prolonged balloon inflation for 4 to 24 hours
after sclerosant injection to maximize sclerosant contact with the variceal endothelium.[1]
[2] However, this prolonged duration can be resource-intensive and challenging for busy
IR departments. Advanced variations like CARTO and PARTO address these limitations
by using coils or vascular plugs to occlude the outflow vein, enabling earlier removal
of the balloon catheter, thereby reducing the procedure time, while also preventing
the risk of systemic sclerosant leakage. Nonetheless, these methods also have technical
challenges, including difficult deployment due to anatomical factors and potential
complications related to these devices.[3]
[4] N-butyl cyanoacrylate glue, although a widely used liquid embolic in embolization
procedures, polymerizes rapidly, carries a higher risk of nontarget embolization and
catheter entrapment. LAVA, similar in composition to onyx, is a nonadhesive, radiopaque
liquid embolic agent composed of ethylene vinyl alcohol copolymer dissolved in DMSO.
The LAVA liquid embolic allows controlled delivery, enabling precise and durable occlusion
of the outflow vein while minimizing embolic migration. This makes LAVA a safer and
more effective choice in the LARTO technique. The authors utilized the LAVA LES,[5] which provided a durable occlusion of the outflow varix, thereby enabling immediate
removal of the balloon-occlusion catheter after sclerosant injection, resulting in
reduced procedural time while also allowing sufficient dwell time for sclerosant.
The LARTO technique using the LAVA embolic system is potentially cost-effective since
plug- or coil-assisted techniques require multiple coils or vascular plugs to completely
occlude the outflow varix, which can add up the cost, whereas only small amount of
LAVA (one vial of 2 mL LAVA 36) was enough in this case to form an occlusive plug.
However, the amount of liquid embolic needed will depend on the size of the outflow
varix and therefore careful review of preprocedural imaging is crucial for success
with this technique. With the increasing availability of liquid embolic agents such
as LAVA, the LARTO technique has the potential to offer another advanced alternative
to the classic BRTO for patients with bleeding gastric varices. Further studies are
warranted to evaluate the broader applicability and long-term efficacy of LARTO technique
as a modification of BRTO.
