Impact of the type of general anaesthesia on recovery of sensory function after sciatic nerve transection and neurorrhaphy

Peripheral nerve injury (PNI) causes long-term sensorimotor impairment, which often leads to disability. In animal models, the choice of general anaesthesia affects not only the success of surgery but also the subsequent rehabilitation. Inhalation anaesthetics provide a rapid recovery of behavioral activity in animals, but can cause uncontrolled movements and muscle stiffness in the early postoperative period, which can affect rehabilitation. This study compared the effect of two types of general anaesthesia - inhalation (isoflurane) and injection (a combination of ketamine and xylazine) - on the recovery of sciatic nerve sensory function in rats after transection and neurorrhaphy. In the group with isoflurane anaesthesia, a sustained decrease in thermal sensitivity on the operated paw and mechanical hypoalgesia on both limbs at the end of the experiment was observed. In contrast, the increase in the threshold to a thermal stimulus was observed only from 2 to 12 weeks with ketamine-xylazine, and mechanical hyperalgesia persisted for only 2 weeks. Injectable anaesthesia promotes immobilisation of the limb and reduces postoperative complications due to the combination with the muscle relaxant xylazine, while isoflurane anaesthesia without premedication can negatively affect the recovery of sensory function.