Ligation is a surgical term that refers to the act of tying off a vessel, duct, or abnormal connection using a suture, clip, or another device to stop the flow of blood, fluid, or other substances.

🔍 In medical context:
To ligate = to tie or clamp a structure to close it off.

Common in procedures involving:

Blood vessels → to stop bleeding.

Fallopian tubes → for sterilization (tubal ligation).

Fistulas → such as CSF venous fistulas, to stop abnormal cerebrospinal fluid drainage.

🧠 In neurosurgery:
Ligation of a CSF venous fistula involves identifying and surgically tying off the fistulous connection between the subarachnoid space and a spinal vein to halt the pathological CSF leak causing spontaneous intracranial hypotension.

In essence, ligation = surgical closure of an unwanted pathway.