A 48-year-old woman from Mumbai with Child-Pugh class B cirrhosis presents with acute variceal bleeding from esophageal varices. After successful endoscopic variceal ligation, she is stabilized. Imaging shows a patent portal vein with flow toward the liver, and the varices are confirmed to originate from portal hypertension. She is now euvolemic and hemodynamically stable. What is the most appropriate next step to prevent variceal rebleeding?