Technique for placement of chronic third cerebroventricular cannula in female goats (Capra hircus)

A practical method for chronic catheterization of the third cerebroventricular space in goats was developed by using a stereotaxic device. In female goats of various ages and weights, a stereotaxically mounted drill was positioned at an angle of 11.5 degrees with the tip of the drill bit located at a skull reference point 2 to 3 mm rostral to the posterior border of Bregma (intersection of the coronal with the sagittal sutures). The hole that was drilled served as the guide for a tight-fitting cannula, which was 20-gauge stainless steel with a stylet. The cannula was advanced by hand to a depth of approximately 40 mm from the top of the skull, positioning the cannula tip in the anterior region of the third ventricle anterior to the massa intermedia. Copious flow of cerebrospinal fluid verified appropriate positioning. The cannula was anchored with dental acrylic and a subcutaneous port system attached via plastic tubing. Cannula placement was assessed after surgery by use of fluoroventriculography. Cannula patency was maintained for 23 months. Minimal complications were seen, maintenance was minimal, and animals were allowed complete freedom of movement with no requirement for jackets or wraps and were used in several consecutive studies. No anesthetic complications were noticed.