However, the imaging study depicted above illustrates the injection of a contrast agent into a sacral cyst. Upon reaching the level of the leak, the contrast agent promptly escapes and enters the subarachnoid space. Evidently, the aforementioned perspective is incorrect.
Since the leakage in sacral cysts is not a one-way valve but rather a bidirectional flow, allowing for the free movement of fluid in and out, the question arises as to why sacral cysts continue to grow. The answer lies in the high hydrostatic pressure of cerebrospinal fluid in the sacrum when the body is upright, continuously expanding the cyst.
Given that sacral cyst leaks are bidirectional, surgical diversion techniques that open up the sacral cyst and dural sac may exacerbate the condition by increasing the size of the leak and the flow rate.