A 58-year-old man with alcohol-related cirrhosis (Child-Pugh B, MELD 13) is admitted with acute hematemesis. Endoscopy confirms actively bleeding esophageal varices despite vasoactive therapy. Endoscopic band ligation achieves transient hemostasis, but rebleeding occurs within 24 hours. He has moderate ascites and a history of a single, well-controlled episode of hepatic encephalopathy six months ago, with no current neurological symptoms. Echocardiography shows normal biventricular function and no pulmonary hypertension. There is no evidence of infection.

Which of the following represents the most appropriate next management step?