A fenestrated tube has an opening (fenestration) in the back of the outer cannula. The front of the tube can be blocked which allows the air to flow upwards to the upper part of the trachea and larynx. A fenestrated tube allows the patient to breathe normally and to speak or cough through the mouth.
A fenestrated trach tube is often used as the final step before trach tube removal. It permits the patient to speak and cough on their own, providing an experimental trial for life after the trach tube.
Multiple fenestrations (sieve) are preferred over a single opening since it better protects the trachea from injury during suctioning and is also associated with a lower risk of granulation tissue formation.