Balloon-occluded Retrograde Transvenous Obliteration (BRTO): Technique and Intraprocedural Imaging

Abstract

Balloon-occluded retrograde transvenous obliteration (BRTO) is an endovascular technique used as a therapeutic adjunct or alternative to transjugular intrahepatic shunts (TIPS) in the management of gastric varices. Occlusion balloons are strategically placed to modulate flow within the gastrorenal or gastrocaval shunt to allow stagnation of the sclerosant material within the gastric varix. The approach and complexity of the procedure depends on the anatomic classification of inflow and outflow veins of the varix. Ethanolamine oleate has been described as the main sclerosant used in this procedure. Recently, foam sclerosants have gained popularity as alternative embolization agents, which provide the advantage of better variceal wall contact and potentially less dose of sclerosant.

Keywords: BRTO; Gastric varices; embolization; liver cirrhosis; portal hypertension; portosystemic shunt.

Figure 1

Balloon-occluded retrograde transvenous obliteration procedural steps. (A) Catheterization of the gastrorenal shunt (arrow). (B) Advancement of an occlusion balloon (arrow) into the shunt and performing retrograde venogram. (C) Retrograde venogram shows opacification of the gastric varices (arrow) as well as the afferent posterior gastric vein (arrow heads). (D) Administration of the sclerosant mixture with the endpoint being filling of the afferent posterior gastric vein (arrowheads).

Figure 2

Classification based on venous drainage. (A) Type A has a shunt with a single draining vein. (B) Type B has a shunt with multiple collateral draining veins. (C) Type C has both a gastrocaval and gastrorenal shunt. (D) Type D has multiple small draining veins and no shunt.

Figure 3

Type A venous outflow. (A) With the occlusion balloon (arrowheads) positioned at the base of the gastrorenal shunt, balloon-occluded retrograde venography shows filling of the gastric varices as well as the afferent vein (arrow). (B) With the occlusion balloon (arrowheads) inflated, the sclerosant was administered with minimal filling of the afferent vein (arrow). (C) Overview of type A venous outflow treatment.

Figure 4

Type B venous outflow. (A) With the occlusion balloon (arrowheads) positioned at the base of the gastrorenal shunt, balloon-occluded retrograde venography shows filling of multiple “leaking” collateral veins including inferior phrenic (black arrow) and perivertebral veins (white arrow).(B) After the occlusion balloon (arrowheads) was advanced beyond the “leaking” collateral veins, venography through a microcatheter (white arrow) now shows opacification of the gastric varices (black arrow).

Figure 5

Type B venous outflow. (A) With the occlusion balloon (arrowheads) positioned at the base of the gastrorenal shunt, balloon-occluded retrograde venography shows filling of the inferior phrenic vein (black arrow). (B) Using a microcatheter (arrow), the vein was catheterized and embolized using metallic coils. (C) With the occlusion balloon (arrowheads) inflated, the sclerosant was administered with minimal filling of the afferent vein (arrow). (D) Overview of type B venous outflow using metallic coils.

Figure 6

Type C venous outflow. (A) With the occlusion balloon positioned at the base of the gastrorenal shunt (not shown), balloon-occluded retrograde venography through a microcatheter (black arrow) shows filling of a gastrocaval shunt (white arrows). (B) A second occlusion balloon was advanced to occlude the gastrocaval shunt (arrowheads) .The sclerosant was administered through a microcatheter (white arrow) with opacification of the varices and minimal filling of the afferent vein (black arrow). (C) Overview of type C venous outflow treatment with a second occlusion balloon.

Figure 7

Classification based on venous inflow. (A) Type 1 gastric varices are supplied by a single afferent gastric vein. This is the most common and simplest type to treat. (B) In type 2, the gastric varices are supplied by multiple afferent gastric veins; and (C) type 3, by single or multiple gastric veins with coexistent gastric veins that are directly contiguous with the shunt, but do not contribute to the varices.

Figure 8

Cone beam computed tomography (CT) utilization in a balloon-occluded retrograde transvenous obliteration procedure. (A) Contrast-enhanced CT scan shows gastric fundal varices (arrow). (B) Cone beam CT after administration of the sclerosant showed opacification of the same gastric fundal varices (arrow).