gms | German Medical Science

Objective: Kaolin-induced hydrocephalus is a well-established small-animal model. To evaluate human implants in vivo, however, small-animal models are not sufficient. Assigning the experimental design to bigger animals is not always feasible since one has to keep in mind that species-dependent characteristics have to be considered. This study was performed to establish Kaolin-induced hydrocephalus in adult pigs. ICP-data and animal care are addressed in particular.

Methods: 10 male pigs weighing 60–70 kg were anesthetized and 10 mg/kg BW Kaolin was injected slowly into the cisterna magna. ICP was monitored using an electronic implant with a pressure sensor, a two-axis-acceleration sensor, a MSP430 microcontroller, a 433 MHz communication chip and a battery for power supply. Imaging studies has been performed preoperatively, at postoperative day 3 and in case of clinical decline. Serial sections were prepared for histopathological examination.

Results: Occlusive hydrocephalus developed 3 to 5 days after surgery. Within 24h after surgery animals demonstrated clinical signs of basal aseptic meningitis. After clinical improvement there was a slow deterioration until hydrocephalus was proven by CCT. B- and P-waves known from human ICP could be demonstrated during ICP monitoring. Slowly increasing ICP paralleled increasing ventricular size.

Conclusions: Kaolin-induced hydrocephalus is feasible in adult pigs. To avoid injuries in symptomatic animals the experimental design has to be adapted. Concerning the ICP data the obtained results indicate that ICP characteristics are comparable in pigs and humans.