Polysulfone tailor-made implant for the surgical correction of a frontoparietal meningoencephalocoele in a cat.

Case summary: A 6-week-old entire female domestic shorthair cat was presented for evaluation of a soft bulge and a palpable skull defect on the forehead, present since adoption a few days earlier. The neurological examination revealed an absent menace response bilaterally and apparent blindness, localising the lesion to the occipital cortex. The main differential diagnoses were meningocoele (MC) and meningoencephalocoele (MEC). Surgical repair was proposed once the cat reached adult size. Meanwhile, the cat developed seizures and was treated with anticonvulsant therapy. At 6 months of age, CT confirmed a frontoparietal MEC with associated porencephaly. Based on a three-dimensional printed skull mould, a polysulfone implant was created. The meninges were dissected from the skin, a durectomy was performed and samples of the protruding brain were obtained. Part of the cerebrospinal fluid was drained until the size of the protruding brain decreased enough to be included below the implant that was anchored on top of the skull with cerclages. Histopathology confirmed the diagnosis of MEC. Three years and 7 months later, the cat had partially recovered vision but continued to seize monthly despite antiepileptic drugs. Relevance and novel information: MC/MEC is a relatively uncommon disease reported in companion animals, and only four cases of surgical management have been described, and did not use a polysulfone tailor-made implant. In human medicine, surgical intervention is the treatment of choice. This case highlights a new implant option for surgical correction of MEC with good long-term result and no complications after 3 years and 7 months.