A 35-year-old woman presented to the emergency department with severe right lower quadrant abdominal pain, nausea, and vomiting. Her pain began acutely and has been steadily progressing over the past 12 hours. On physical examination, she has significant tenderness and guarding in the right lower quadrant. The surgical team is suspecting acute appendicitis and is proceeding for an appendectomy using McBurney’s incision.
Which of the following nerves is most commonly at risk for damage during an appendectomy with a McBurney’s incision?
A. Subcostal nerve
B. Iliohypogastric nerve
C. 11th thoracic nerve
D. 10th thoracic nerve
The Correct Answer is: B. Iliohypogastric nerve
Explanation:
Iliohypogastric Nerve (B):
– The iliohypogastric nerve is formed from the L1 nerve root. It serves sensory functions and provides the skin of the lower abdomen and the upper portion of the hip. It also provides motor fibers to the muscles—namely, the internal oblique and transverse abdominis.
– A McBurney’s incision is made in the right lower quadrant of the abdomen, and the iliohypogastric nerve is most commonly at risk for injury due to its course of anatomy.
– Injury to this nerve may bring some postoperative complications, like numbness or pain in the lower part of the abdomen up to the hip area.
Explanation of Incorrect Options:
– Subcostal nerve (A): The subcostal nerve originates from the T12 nerve root, runs near the lower edge of the 12th rib, innervates the muscles of the abdominal wall, and the skin of the lower abdomen. It has less risk of being injured with a McBurney’s incision more distally in the abdomen.
– 11th thoracic nerve (C): Runs along the 11th intercostal space. It innervates the muscles of the abdominal wall and skin; less commonly, it is damaged in a McBurney’s incision compared to the iliohypogastric nerve.
– 10th thoracic nerve (D): The 10th thoracic nerve runs at the level of the 10th intercostal space and also innervates the abdominal wall muscles and skin. This nerve is generally not at great risk with a McBurney’s incision.
In other words, anatomically and in its course, the iliohypogastric nerve is the most vulnerable nerve in making a McBurney’s incision. So, the answer would be Iliohypogastric nerve of option B.