Certified Surgical Technologist (CST) Practice Exam 2026 – All-in-One Guide to Master Your Certification!

A fistula is characterized as an abnormal connection or tract that develops between two epithelial-lined surfaces and remains open at both ends. This can occur between organs or vessels, often as a result of injury, infection, or disease. For instance, a fistula may form between the intestines and the skin after surgery or due to inflammatory conditions, allowing for abnormal communication between these structures.

The distinction of a fistula lies in the fact that it connects two separate anatomical structures, contrasting with a sinus, which is typically a sac-like cavity that may not have such a direct communication with another hollow organ. Herniation refers to the protrusion of an organ through the wall of the cavity that contains it and does not describe a tract, while epithelization refers to the process of the epithelial tissue healing or regenerating, which again does not pertain to the definition of a tract. Thus, the definition and context of a fistula directly align with the question regarding an abnormal tract that is open at both ends.