Fenestrated

Fenestrated is an adjective describing something that has openings or windows, derived from the Latin fenestra meaning window. The term is used across disciplines to indicate perforations, holes, or arranged openings in a barrier or surface.

In biology and medicine, fenestration refers to small pores called fenestrae in the endothelium of certain blood vessels. Fenestrated capillaries allow rapid exchange of small molecules between blood and surrounding tissue while restricting larger proteins. They are common in organs such as the kidneys, endocrine glands, choroid plexus, and the intestinal mucosa; liver sinusoids also feature a fenestrated endothelium. The degree of fenestration can vary and may be regulated by physiological conditions.

In vascular surgery and endovascular therapy, fenestrated structures appear in devices such as fenestrated stent grafts. These grafts include custom openings that align with branch vessels (for example, visceral arteries) to preserve blood flow while repairing aneurysms. Fenestrated grafts are used in complex thoracoabdominal or visceral aneurysm cases and require careful planning to match patient anatomy.

In architecture, fenestration describes the design and placement of openings in a building’s facade, including windows, doors, and perforations. The term covers both the number and arrangement of openings and their impact on light, ventilation, and aesthetics.

In botany, fenestration can describe leaves with holes or perforations, a feature seen in some species such as Monstera. This usage reflects the broader sense of “opening” embedded in the term.