Modification of a method for cannulation of the cisterna magna in sheep to enable chronic collection of cerebrospinal fluid.

A method is described for chronic cannulation of the cisterna magna to enable repeated sampling of cerebrospinal fluid from conscious, ambulatory sheep by means of a flexible vinyl tube. Ease of sampling and duration of cannula patency are similar to those obtained with rigid, metal cannulae, but this modified method minimizes the degree of surgical intervention, and possible trauma, occurring during placement of the cannula.