Which of the following structures forms the anterior boundary of the lesser omentum?

Explanation

## The Lesser Omentum: Anterior Boundary ### Definition and Structure The lesser omentum is a double fold of peritoneum connecting the lesser curvature of the stomach and the proximal duodenum to the liver (hepatic porta). It is a critical anatomical space in abdominal surgery. ### Anterior Boundary (Free Edge) **Key Point:** The **anterior boundary (free edge) of the lesser omentum** contains three vital structures: 1. **Hepatic artery proper** (medially) 2. **Portal vein** (posteriorly) 3. **Common bile duct** (laterally) These three structures are collectively known as the **hepatoduodenal ligament**, which is the anterior/free edge of the lesser omentum. ### Mnemonic **Mnemonic:** **HAP** = **H**epatic artery, **A**nterior (free edge), **P**ortal vein Or remember: **"Anterior to Posterior"** = Hepatic artery → Portal vein → Bile duct (but bile duct is actually lateral, not posterior) ### Clinical Pearl **Clinical Pearl:** The hepatoduodenal ligament is the site of the **Pringle maneuver** — clamping this ligament during hepatic surgery to control bleeding. Surgeons must identify these three structures to avoid iatrogenic injury during hepatic or gastric surgery. ### Comparison Table: Omental Boundaries | Boundary | Structures | Ligament Name | | --- | --- | --- | | **Anterior (Free Edge)** | Hepatic artery, portal vein, bile duct | Hepatoduodenal ligament | | **Posterior** | Peritoneum (posterior layer) | — | | **Superior** | Liver (hepatic porta) | — | | **Inferior** | Lesser curvature of stomach + proximal duodenum | — | **High-Yield:** The hepatoduodenal ligament is the anterior/free edge of the lesser omentum and contains the three most important vascular and biliary structures in the abdomen.