**Question:** Thompson's Operation for Lymphoedema is

A. Lymphaticovenular anastomosis
B. Lymph node dissection
C. Lymph node transplantation
D. Lymph node flap

**Correct Answer:** A. Lymphaticovenular anastomosis

**Core Concept:**
Thompson's Operation, also known as Lymphaticovenular anastomosis, is a surgical procedure used in the management of lymphoedema, a condition characterized by swelling of the limbs or other body parts due to impaired lymphatic drainage. Lymphoedema can be classified into primary (congenital or acquired) and secondary (caused by injury, infection, or surgery). The goal of Thompson's Operation is to restore proper lymphatic drainage and reduce the swelling by creating anastomosis between the dilated lymphatic vessels and the adjacent veins.

**Why the Correct Answer is Right:**
Thompson's Operation focuses on anastomosis of the dilated lymphatic vessels (called lymphovenous anastomosis) to the adjacent veins. This procedure aims to bypass the obstructed or dysfunctional lymphatic vessels, allowing the excess lymphatic fluid to be transported back to the venous system, reducing the swelling caused by lymphoedema.

The procedure involves identifying the dilated lymphatic vessels and the nearby veins. A small portion of the dilated lymphatic vessel is harvested and sutured to the vein, creating an anastomosis. This allows the lymphatic fluid to flow into the vein instead of accumulating in the affected limb. Thompson's Operation is effective in reducing lymphoedema in cases where the primary cause is obstruction or dysfunction of the lymphatic system.

**Why Each Wrong Option is Incorrect:**

**B. Lymph node dissection:**
This procedure involves the removal of lymph nodes to treat lymphadenopathy or lymph node enlargement. In contrast to Thompson's Operation, lymph node dissection does not address the primary cause of lymphoedema (obstructed or dysfunctional lymphatic vessels) and can even worsen the condition by disrupting the remaining lymphatic system.

**C. Lymph node transplantation:**
Transplanting lymph nodes does not address the primary cause of lymphoedema, which is the dysfunction or obstruction of the lymphatic system. This procedure involves transplanting lymph nodes from a donor to the affected limb, which doesn't solve the underlying issue and might introduce complications from immune response to the transplanted nodes.

**D. Lymph node flap:**
A lymphatic flap is a tissue flap containing lymphatics and blood vessels, which is harvested from a healthy area of the body and transplanted to the affected limb. While this procedure aims to improve lymphatic drainage, it does not address the primary cause of lymphoedema, which is the dysfunction or obstruction of the lymphatic system. Additionally, it might not be effective in all cases and may have potential complications from the surgical procedure and tissue integration.

**Clinical Pearl:**
Thompson's Operation (lymphaticovenous anastomosis) is the appropriate surgical approach for managing lymphoedema,