Question

Which of the following nerves is commonly damaged during a McBurney's incision?

• A. Subcostal nerve
• B. 10th thoracic nerve
• C. 11th thoracic nerve
• D. Iliohypogastric nerve

Hint:

Which nerve runs between internal oblique and transversus at the level of the right iliac fossa?

Answer 1

The Correct Option is D

Step 1: The McBurney or grid-iron incision is the muscle-splitting incision used for open appendicectomy. It is placed obliquely in the right iliac fossa, centred at McBurney's point about 5 cm above and medial to the anterior superior iliac spine, at right angles to the spino-umbilical line.

Step 2: As the surgeon splits the external oblique, internal oblique and transversus abdominis along their fibres, the iliohypogastric nerve, which runs between the internal oblique and transversus, lies directly in the line of dissection and is the nerve most often injured.

Step 3: Damage to the iliohypogastric nerve weakens the conjoint tendon and the lower fibres of the internal oblique and transversus, which can predispose to a right inguinal hernia.

Step 4: The subcostal nerve and the 10th and 11th thoracic nerves run at higher levels and are not in the path of a right iliac fossa incision, so they are incorrect.