What is a sural nerve block?
A sural nerve block is a procedure for anesthetizing a part of the calf, lower leg, heel and foot. An anesthetic solution is injected adjacent to the Achilles tendon on the outer side of the foot. The anesthetic blocks the transmission of pain signals from injury or surgery in these parts of the lower leg.
The sural nerve is a terminal branch of the sciatic nerve. The sciatic nerve provides motor function and sensation to the back of the thigh and the entire lower leg from the knee down. The sciatic nerve has two major branches:
- Tibial nerve
- Common peroneal (fibular) nerve
The sural nerve is a sensory nerve made up of a branch each from both the tibial and peroneal nerves. The sural nerve passes down the calf and lower leg adjacent to the Achilles tendon, into the little toe-side of the foot. The sural nerve is relatively superficial and can be blocked by an anesthetic injection at a variety of levels above, or at the ankle.
What does the sural nerve do?
The sural nerve and its branches transmits information of sensation from part of the calf, lower leg, heel and foot to the brain. The sural nerve transmits pain signals to the brain when injury or trauma occurs in these parts of the lower leg.
What does sural nerve pain feel like?
Injury or irritation to the sural nerve causes a burning pain in the calf and below. Sural nerve damage may also cause tingling, hypersensitivity, or numbness in the affected region.
Why is a sural nerve block performed?
A sural nerve block may be performed alone, or in combination with other nerve blocks depending on the area that requires anesthesia. A sural nerve block is performed to provide:
A sural nerve block is performed during surgical procedures in the lateral part of the calf, lower leg, heel and foot, including:
- Repair of wounds and lacerations
- Treatment of ankle fracture or dislocation, as part of an ankle block
- Incision and drainage of abscess
- Removal of foreign body
A sural nerve block is a better alternative to a local tissue infiltration anesthesia because it:
- Requires a lower volume of anesthetic agent to achieve anesthesia in a larger area.
- Requires fewer injections, which reduces the trauma to the patient.
- Provides selective pain relief and reduces the need for sedation and opioids.
- Provides longer-lasting anesthesia and analgesia (pain relief).
A sural nerve block is avoided for any of the following reasons: