**Question:** Vascular inflow occlusion of the liver is by

A. Hepatic artery embolization
B. Portal vein embolization
C. Hepatic vein embolization
D. Both A and B

**Correct Answer:** D. Both A and B

**Core Concept:** Vascular inflow occlusion of the liver is a procedure used in interventional radiology to reduce the size of a large liver tumor or to increase the liver's size for transplantation by temporarily interrupting the blood supply to the affected area.

**Why the Correct Answer is Right:** The liver receives blood from two major vessels: the hepatic artery and the portal vein. The hepatic artery (A) carries oxygenated blood from the aorta, while the portal vein (B) brings deoxygenated blood from the gastrointestinal tract. In cases of liver tumors, occluding these vessels can reduce the blood supply to the tumor, leading to its shrinkage or necrosis. This technique is also used to increase the size of the liver for transplantation by reducing the volume of the patient's liver.

**Why Each Wrong Option is Incorrect:**

**Option C (Hepatic vein embolization):**
Hepatic veins (C) drain the oxygenated blood from the liver back into the inferior vena cava. Embolization of hepatic veins would not achieve the intended goal of reducing liver size or affecting liver tumors, as it only affects the drainage of deoxygenated blood from the liver and does not directly impact the hepatic artery supply or liver tumors.

**Option D (Hepatic artery embolization):**
Embolization of the hepatic artery (D) would reduce the blood supply to the liver, as mentioned earlier, but it may not be the most effective method for liver size reduction or tumor management, as the portal vein supplies a significant amount of blood to the liver.

**Option A (Both A and B):**
By occluding both the hepatic artery (A) and the portal vein (B), we can effectively reduce the liver volume, as both these vessels supply blood to the liver. This method ensures that the liver tumor will shrink or die due to lack of oxygen and nutrients.

**Core Concept:** Vascular inflow occlusion is a minimally invasive procedure used in interventional radiology to treat liver tumors and adjust liver size for transplantation. By occluding the hepatic artery and portal vein, the liver volume and tumor are affected, leading to shrinkage or necrosis.

**Clinical Pearls:**
1. Vascular inflow occlusion is a valuable tool for liver tumor management and liver volume adjustment in transplantation.
2. This procedure is performed under imaging guidance and can be tailored to target specific vessels to achieve the desired outcome.
3. Complications of this procedure may include post-embolization syndrome, abscess formation, and liver failure. Careful patient selection and proper technique are essential for successful outcomes and reduced complications.