**Question:** Highly selective vagotomy preserves

A. the antral glands
B. the pyloric sphincter
C. the cardiac mucosa
D. the duodenal mucosa

**Core Concept:**
Highly selective vagotomy (HSV) is a modification of traditional vagotomy, which involves only the division of the anterior two-thirds of the greater curvature of the stomach, preserving the posterior one-third and the fundus. This modification aims to reduce the side effects associated with traditional vagotomy, such as delayed gastric emptying and malabsorption. HSV selectively interrupts the pathways that mediate gastric acid secretion, preserving the structures responsible for maintaining normal gastric functions.

**Why the Correct Answer is Right:**
Highly selective vagotomy preserves the antral glands (Option A) because these glands produce mucus and bicarbonate ions, which are essential for maintaining the gastric mucosa's protective barrier against gastric acid and preventing erosions. By preserving the antral glands, HSV reduces the risk of post-vagotomy complications like gastric ulcers and bleeding.

**Why Each Wrong Option is Incorrect:**
a) HSV does not spare the pyloric sphincter (Option B), which is responsible for controlling the passage of gastric contents into the duodenum. This may lead to post-vagotomy complications like dumping syndrome, diarrhoea, and malabsorption.

b) HSV does not preserve the cardiac mucosa (Option C), which is involved in the production of mucus and bicarbonate ions needed for gastric mucosal defense against acid. This may result in increased risk of post-vagotomy complications like peptic ulcers and bleeding.

c) HSV does not spare the duodenal mucosa (Option D), which is crucial for normal digestion and absorption of nutrients. Incomplete preservation of the duodenal mucosa can lead to malabsorption and nutrient deficiencies.

**Clinical Pearl:**
Highly selective vagotomy is selectively performed when dealing with severe peptic ulcers, typically in patients with refractory ulcers or complications like bleeding or perforation. By preserving the key structures mentioned above, HSV aims to minimize post-vagotomy complications and improve patient outcomes.