Strata and Strata NSC shunts with patented adjustable valve mechanism. Strata NSC LP Adjustable Lumboperitoneal Shunt system from Medtronic. A shunt usually consists of two catheters and a one-way valve. The valve regulates the amount, flow direction, and pressure of cerebrospinal fluid out of the . Delta valves minimize overdrainage of cerebrospinal fluid (CSF). They’re part…