Isoflurane maintenance of neuroanaesthesia in two dogs with hydrocephalus and syringohydromyelia undergoing ventriculoperitoneal shunt surgery

A two-year-old spayed female great dane crossbreed dog and a three-year-old spayed female Yorkshire terrier were presented for surgical correction of hydrocephalus and syringohydromyelia. Obstruction of cerebrospinal fluid flow and associated increase in cerebrospinal fluid volume commonly result in an elevated intracranial pressure. During anaesthesia, maintaining an optimal balance between intracranial pressure and cerebral perfusion is crucial to avoid neuronal damage. Volatile anaesthetics are the most commonly used drugs for maintaining anaesthesia in veterinary practice but have the potential to cause an increase in intracranial pressure through vasodilation. This case series describes inhalational maintenance of neuroanaesthesia for ventriculoperitoneal shunt surgery with isoflurane. Interventions applied to manipulate the anaesthetic drug’s effects on intracranial pressure to maintain optimal cerebral perfusion are described.