The effects of cryosurgery and cryoprotectants on peripheral nerve function

Area of Science:

• Orthopedics
• Neurosurgery
• Regenerative Medicine

Background:

• Cryosurgery is a valuable treatment for musculoskeletal tumors, but peripheral nerve injury is a known complication.
• Cryoprotectants like dimethyl sulfoxide (DMSO) improve cell survival in vitro but lack in vivo studies for nerve protection.

Purpose of the Study:

• To investigate the in vivo efficacy of dimethyl sulfoxide (DMSO) as a cryoprotectant for peripheral nerves against cryoinjury.
• To evaluate the impact of DMSO pretreatment on neurologic recovery following cryoablation of the sciatic nerve.

Main Methods:

• The study involved three groups: sham operation, sciatic nerve freezing, and sciatic nerve freezing with DMSO pretreatment.
• Neurologic recovery was assessed over ten weeks using gait analysis (sciatic function index), muscle weight ratios, and histological evaluation.

Main Results:

• The DMSO-treated group showed significantly impaired functional recovery (SFI: -34.1%) compared to the freezing-only group (-4.2%) and sham controls (-2.4%).
• Muscle weight ratios were significantly lower in the DMSO-treated group (70.6%) versus the freezing-only group (88.2%), indicating muscle atrophy.
• Histological evaluation corroborated the functional and muscle weight data, showing detrimental effects of DMSO.

Conclusions:

• Dimethyl sulfoxide (DMSO) failed to protect peripheral nerves from cryoinjury in an in vivo model.
• Instead of providing neuroprotection, DMSO exacerbated functional deficits and muscle atrophy following cryoablation.
• The findings suggest that DMSO is not suitable as a cryoprotectant for peripheral nerves in surgical cryoablation procedures.