The objective of this observational study is to compare the safety profile of auxiliary liver transplantation using small-for-size grafts with that of conventional liver transplantation and to evaluate the efficacy of this technique. The primary research question it seeks to investigate is:

"What are the differences in safety and efficacy between auxiliary liver transplantation utilizing small-for-size grafts and conventional liver transplantation for the treatment of portal hypertension?"

Inclusion Criteria:

1. Age > 14 years.
2. Presence of decompensated portal hypertension.
3. Meeting the indications for liver transplantation surgery.
4. International Normalized Ratio (INR) < 2.4.
5. Scheduled to undergo orthotopic auxiliary partial liver transplantation or conventional liver transplantation.

Exclusion Criteria:

1. Rare liver-related anatomical variations.
2. Presence of contraindications to liver transplantation combined with malignant tumors.
3. Grade III or higher portal vein thrombosis.
4. Severe systemic diseases unrelated to the etiology or complications of portal hypertension.
5. Special surgical procedures such as dual-graft liver transplantation.
6. Special graft sources including domino liver transplantation.
7. Liver re-transplantation.

Patients with cirrhotic portal hypertension who were treated at the Liver Transplantation Center of Beijing Friendship Hospital, Capital Medical University between January 2014 and December 2028, and who underwent either auxiliary liver transplantation using small-for-size grafts (study group) or conventional liver transplantation (control group).