Question

Injury to which nerve during a herniorrhaphy may cause paresthesia at the root of the scrotum and base of the penis?

• A. Ilioinguinal
• B. Pudendal
• C. Genitofemoral
• D. Iliohypogastric

Hint:

This nerve runs in the inguinal canal itself and exits through the superficial ring, right in the surgical field of a hernia repair.

Answer 1

The Correct Option is A

Step 1: Recall the course of the ilioinguinal nerve.
The ilioinguinal nerve runs through the inguinal canal alongside the spermatic cord and leaves through the superficial inguinal ring. It lies quite superficial in the operative field used for inguinal hernia repair, so it is easily caught in a suture or stretched by a retractor.

Step 2: Recall what it supplies.
It carries sensation from the skin at the root of the penis, the upper part of the scrotum (or the mons pubis and labia majora in a woman), and the adjoining upper inner thigh. Damage to it during herniorrhaphy shows up as numbness, tingling, or burning pain in exactly this area.

Step 3: Check why the pudendal nerve is wrong.
The pudendal nerve travels through the pudendal canal in the perineum and supplies the deeper perineal structures and external genitalia through a different route altogether. It is not exposed in the field of a standard inguinal hernia operation.

Step 4: Check why the genitofemoral nerve is wrong.
Its genital branch runs with the spermatic cord and mainly supplies the cremaster muscle, so injury to it classically causes loss of the cremasteric reflex, not the sensory change described here at the root of the scrotum and penis.

Step 5: Check why the iliohypogastric nerve is wrong.
This nerve supplies the skin over the lower abdomen just above the pubic bone, a region above and separate from the root of the scrotum and penis, so it does not match the symptom described.

Step 6: Final answer.
Injury to the ilioinguinal nerve during herniorrhaphy causes paresthesia at the root of the scrotum and base of the penis.