A 75-year-old male patient is scheduled to undergo elective orchiectomy for prostate cancer. The patient has selected spinal anesthesia. What is the minimum dermatomal level that must be achieved to carry out this operation?

A 75-year-old male patient is scheduled to undergo elective orchiectomy for prostate cancer. The patient has selected spinal anesthesia. What is the minimum dermatomal level that must be achieved to carry out this operation?

• A. T1
• B. T4
• C. T10
• D. L3

Answer: (C)

In spinal anesthesia, you must block the nerve roots that carry sensation from the surgical field. For an orchiectomy, the pain signals from the testis travel with sympathetic fibers that enter the spinal cord at the thoracic level corresponding to the area of the umbilicus. Blocking to that level is the minimum needed to prevent pain from the procedure. If the block stays lower, the patient can still feel discomfort from the testicular region; if it goes higher, you’re blocking more than necessary and may see more hemodynamic effects. The skin of the scrotum also gets input from the ilioinguinal nerve (lower abdominal/inguinal region), but the key demand for this operation is to reach the thoracic level of the umbilicus to cover the testicular pain pathways. Therefore, the minimum level is the thoracic dermatome at the umbilical level.

In spinal anesthesia, you must block the nerve roots that carry sensation from the surgical field. For an orchiectomy, the pain signals from the testis travel with sympathetic fibers that enter the spinal cord at the thoracic level corresponding to the area of the umbilicus. Blocking to that level is the minimum needed to prevent pain from the procedure. If the block stays lower, the patient can still feel discomfort from the testicular region; if it goes higher, you’re blocking more than necessary and may see more hemodynamic effects. The skin of the scrotum also gets input from the ilioinguinal nerve (lower abdominal/inguinal region), but the key demand for this operation is to reach the thoracic level of the umbilicus to cover the testicular pain pathways. Therefore, the minimum level is the thoracic dermatome at the umbilical level.