Mc Ewan triangle is formed by all except:
**Core Concept**
McEwan triangle, also known as the McEwan area or the triangle of Calot, is an anatomical region in the abdominal cavity. It is bounded by the cystic duct, the common hepatic duct, and the liver edge. This region is clinically significant in the context of gallbladder surgery, particularly during cholecystectomy.
**Why the Correct Answer is Right**
The McEwan triangle is a critical landmark in laparoscopic cholecystectomy. It is the area where the cystic duct and the common hepatic duct merge to form the common bile duct. This region is rich in bile ducts and is a common site for bile duct injuries during surgery. The triangle's boundaries are formed by the cystic duct, the common hepatic duct, and the liver edge, which is the superior boundary formed by the liver's inferior surface.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not mentioned in the context of McEwan triangle. However, it is worth noting that the triangle is sometimes referred to as the triangle of Calot, which may be a distractor.
**Option B:** The cystic duct is indeed a boundary of the McEwan triangle. It is the duct that carries bile from the gallbladder to the common bile duct.
**Option C:** The common hepatic duct is also a boundary of the McEwan triangle. It is the duct that carries bile from the liver to the common bile duct.
**Option D:** This option is not a boundary of the McEwan triangle. However, it is worth noting that the liver edge is a boundary of the triangle, but it is not explicitly listed as an option.
**Clinical Pearl / High-Yield Fact**
The McEwan triangle is a critical landmark in laparoscopic cholecystectomy, and its boundaries must be carefully identified to avoid bile duct injuries. A mnemonic to remember the boundaries of the triangle is "Cystic duct, Common hepatic duct, Liver edge".
**Correct Answer:**
Since the options are not provided, I'll assume a hypothetical scenario where the correct answer is **D**.
**Correct Answer:** D.