**Core Concept**
Portocaval anastomosis refers to the connections between the portal circulation and the systemic circulation. These anastomoses are crucial for the regulation of blood flow and pressure in the liver and portal system. They are formed by the presence of capillary beds and small veins that connect the portal system to the hepatic veins and inferior vena cava.

**Why the Correct Answer is Right**
The correct answer is A because the gastroepiploic-esophageal anastomosis is indeed a portocaval anastomosis. This anastomosis is formed by the connection between the left gastroepiploic vein, which drains into the portal vein, and the esophageal branches of the azygos vein, which drain into the systemic circulation. This connection allows for the exchange of blood between the portal and systemic circulations.

**Why Each Wrong Option is Incorrect**
* **Option B:** The splenicorenal anastomosis is also a portocaval anastomosis, as it connects the splenic vein with the left renal vein, allowing for blood exchange between the portal and systemic circulations.
* **Option C:** The coronary-portal anastomosis is another example of a portocaval anastomosis, as it connects the coronary veins with the portal vein, allowing for the exchange of blood between the systemic and portal circulations.
* **Option D:** This option is not a portocaval anastomosis. However, since the question asks for the exception, we need to know which option is not a portocaval anastomosis.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that portocaval anastomoses are critical for maintaining liver blood flow and pressure, and their presence or absence can impact liver function and overall circulation.

**Correct Answer:** A.