**Core Concept**
Thromboangiitis obliterans, also known as Buerger's disease, is a rare disorder characterized by inflammation and thrombosis of small and medium-sized blood vessels, leading to ischemia and tissue damage. This condition typically affects the limbs, particularly the hands and feet.

**Why the Correct Answer is Right**
Thromboangiitis obliterans is a non-atherosclerotic, non-inflammatory vascular disorder. The exact pathophysiology is not well understood, but it is believed to involve an abnormal immune response, smoking, and genetic predisposition. The clinical features of thromboangiitis obliterans include recurrent episodes of limb ischemia, pain at rest, and gangrene. These symptoms are due to the inflammation and thrombosis of blood vessels, leading to reduced blood flow to the affected limbs.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is actually a common clinical feature of thromboangiitis obliterans. Recurrent episodes of limb ischemia are a hallmark of this condition.

**Option B:** This option is incorrect because pain at rest is a characteristic symptom of thromboangiitis obliterans. Patients typically experience severe pain in the affected limb, which is exacerbated by rest and relieved by exercise.

**Option C:** This option is incorrect because gangrene is a possible complication of thromboangiitis obliterans. The reduced blood flow to the affected limbs can lead to tissue damage and gangrene, which may require amputation.

**Clinical Pearl / High-Yield Fact**
Thromboangiitis obliterans is strongly associated with smoking, and quitting smoking is essential for preventing disease progression and reducing the risk of complications.

**Correct Answer:** D