Patent

Patent is a medical adjective meaning ‘open’ or ‘unobstructed’. When applied to a vessel, duct, or anatomical opening, it means the structure is not blocked or closed and is allowing normal passage of blood or other fluids. The term is the opposite of ‘occluded’ (blocked) or ‘stenosed’ (narrowed).

In cardiology, the most common use of the term is in patent ductus arteriosus (PDA), where the ductus arteriosus (a fetal vessel connecting the aorta and pulmonary artery) remains open after birth when it should have closed. Similarly, a patent foramen ovale (PFO) describes the foramen ovale (the inter-atrial opening present in all fetuses) remaining open in adult life rather than sealing at birth.

The term is also used to describe successful outcomes in coronary intervention and bypass surgery. A patent coronary artery bypass graft or stent is one that remains open and allowing blood flow at a follow-up assessment. High patency rates are a key measure of success in revascularisation procedures, as restenosis (re-narrowing) or thrombosis can occur over time.

In basic life support and airway management, ‘maintaining a patent airway’ means keeping the patient’s airway open and unobstructed. This is a fundamental priority in emergency resuscitation; in an unconscious patient, the tongue can fall back against the pharynx and obstruct the airway, which is managed by head-tilt chin-lift or jaw thrust manoeuvre.