Commonest complication of Zenker&;s diveiculum is
**Core Concept**
Zenker's diverticulum is a mucosal herniation through a weakness in the muscular wall of the pharynx, specifically at the cricopharyngeal muscle junction. This condition can lead to various complications due to food accumulation and potential aspiration.
**Why the Correct Answer is Right**
The correct answer is **A. Aspiration pneumonia**. This complication arises from the accumulation of food and saliva in the diverticulum, which can lead to bacterial overgrowth and subsequent aspiration of these contents into the airway. Aspiration pneumonia is a serious and potentially life-threatening condition that requires prompt medical attention.
**Why Each Wrong Option is Incorrect**
* **Option B:** Dysphagia is a common symptom of Zenker's diverticulum, but it is not the most common complication.
* **Option C:** Regurgitation of food is also a common symptom, but it is not a complication in the same sense as aspiration pneumonia.
* **Option D:** Esophageal stricture is a potential complication of Zenker's diverticulum, but it is not the most common one.
**Clinical Pearl / High-Yield Fact**
It's essential to note that patients with Zenker's diverticulum often present with dysphagia, regurgitation, and aspiration pneumonia, making a high index of suspicion and prompt evaluation and treatment crucial.
**Correct Answer: A. Aspiration pneumonia**