BRTO, or balloon-occluded retrograde transvenous obliteration, is a minimally invasive procedure used to treat dangerous enlarged veins (varices) in the stomach. It works by threading a catheter through a vein, inflating a small balloon to block blood flow, and injecting a chemical that seals off the swollen veins. Originally refined in Japan, BRTO has become a widely used alternative to other interventions for people with liver disease who develop gastric varices, which can rupture and cause life-threatening bleeding.
Why Gastric Varices Need Treatment
Gastric varices form when chronic liver disease, most often cirrhosis, causes a backup of pressure in the portal vein, the main blood vessel feeding the liver. That pressure forces blood to reroute through smaller veins around the stomach, which aren’t designed to handle the load. These veins swell and thin out, creating a risk of sudden, severe bleeding.
Unlike esophageal varices, which sit higher up and can often be treated with endoscopic banding, gastric varices are harder to reach and don’t respond as well to standard endoscopic techniques. BRTO was developed specifically to address this problem from the venous side rather than through the digestive tract.
Who Is a Candidate for BRTO
BRTO is typically recommended for people who have gastric varices that have already ruptured and bled, varices that appear at high risk of rupturing based on their size and surface markings, or varices that are growing larger over time. It’s also used in patients experiencing hepatic encephalopathy, a condition where toxins build up in the blood because a large portosystemic shunt (an abnormal bypass channel) is diverting blood away from the liver. By sealing off that shunt, BRTO forces more blood back through the liver for proper filtering.
The procedure requires a specific type of venous anatomy to work. Patients need a draining vein, most commonly the gastrorenal shunt, that the catheter can access. When that anatomy isn’t present or the draining pathway is too complex, alternative approaches may be needed.
How the Procedure Works
BRTO is performed by an interventional radiologist, typically under conscious sedation. The doctor inserts a catheter through a large vein, usually in the groin or neck, and guides it under imaging into the outflow vein that drains the gastric varices. Once the catheter tip is in position, a small balloon at its end is inflated. This blocks blood from flowing out of the varix.
With the outflow sealed, the doctor injects a sclerosant, a chemical agent that irritates and permanently scars the vein walls shut. The specific sclerosant varies by region. In Asia, a liquid form of ethanolamine oleate (at 5% concentration) mixed with contrast dye has been the standard. In the United States, foam-based agents like sodium tetradecyl sulfate or polidocanol are more common. Foam sclerosants fill the varix more completely and require smaller volumes.
The balloon stays inflated for a period of hours to give the sclerosant time to work. After confirming the varices are thrombosed (clotted off), the balloon is deflated and the catheter is removed.
Success Rates
BRTO has strong technical results. Across studies evaluating 580 procedures, the technical success rate was 91%. Among procedures that were technically successful, 94% achieved complete obliteration of the gastric varices. Some patients need a second session: cumulative success climbs from about 71% after one session to 88% after two and 91% after three.
The rebleeding rate after successful BRTO is notably low. One comparative study of 77 BRTO patients and 27 TIPS patients found a one-year rebleeding rate of just 2% for BRTO versus 20% for TIPS. Another smaller study reported rebleeding and encephalopathy rates of 0% for BRTO compared with 15% and 31% for TIPS, respectively.
BRTO Compared With TIPS
TIPS (transjugular intrahepatic portosystemic shunt) is the other major option for gastric varices. It works in the opposite direction: rather than sealing off the abnormal blood flow, TIPS creates a new channel inside the liver to relieve portal pressure. Both procedures are effective, but they suit different clinical situations.
BRTO tends to produce lower rebleeding rates and does not carry the risk of hepatic encephalopathy that TIPS does. In one study, five-year survival was 76% after BRTO compared with 40% after TIPS. That survival advantage was most pronounced in patients with less severe liver disease (Child-Pugh class A). For patients with more advanced liver dysfunction, survival outcomes were similar between the two procedures.
The trade-off is that BRTO eliminates a shunt that was relieving portal pressure. Closing that pressure valve can worsen other problems, which is the basis for BRTO’s main complications.
Risks and Complications
The most significant downside of BRTO is what happens to portal pressure after the shunt is closed. With the bypass sealed, more blood is forced into the portal system, which can worsen or create new problems elsewhere.
- Worsening esophageal varices: Up to 33% of patients develop new or worsening esophageal varices after BRTO, and some of these can bleed. This is why follow-up endoscopy is important.
- Worsening ascites: About 22% of patients develop increased fluid buildup in the abdomen after the procedure.
These complications don’t mean the procedure failed. They reflect the underlying portal hypertension being redistributed rather than resolved. Most centers plan for this by monitoring patients closely after BRTO and treating esophageal varices with banding if they develop.
Recovery and Follow-Up
BRTO generally requires an overnight hospital stay. Most patients recover quickly since the procedure involves only a small catheter insertion site rather than a surgical incision. A follow-up CT scan is typically scheduled about one month after the procedure to confirm the varices have been successfully obliterated and to check for any new complications. Ongoing endoscopic surveillance is also standard to watch for the development of esophageal varices.
One additional benefit that emerges over time: because BRTO redirects more blood flow through the liver, it has been shown to improve the liver’s functional reserve. For patients with cirrhosis, this can translate into better overall liver function in the months following the procedure.