After respiratory weaning, decannulation is sought. To do this, the tracheal cannula is first unblocked, so that patients no longer breathe in and out through the cannula, but (at least partially) "passing" the cannula by the natural route. In the presence of tracheal stenosis there is increased breathing effort, possibly restlessness and stridor. This constellation of symptoms suggests the suspicion of tracheal stenosis, so in the next step a tracheoscopy is performed to confirm or exclude tracheal stenosis. In case of symptomatic tracheal stenosis and at least 30-50% stenosis of the trachea (clinical symptoms can be expected from a 30-50% stenosis) then appropriate therapy (here: cryotherapy, other techniques only in exceptional cases) is planned. The goal is to be able to remove the tracheal cannula (long term) after successful therapy, so that patients do not have to be permanently provided with a tracheal cannula. There is no definitive/evidence-based standard therapy for the treatment of tracheal stenosis. Cryotherapy is a gentle therapy that has already been applied and described for the treatment of tracheal stenosis (see above). The examination is performed as part of an analgesic dose, as is routine for a bronchoscopy (in-house SOP). After treatment, a follow-up is planned for about 10 days later.

Inclusion Criteria:

• Tracheal stenosis after percutaneous tracheotomy.

Exclusion Criteria:

• Pregnant or breast-feeding women of childbearing potential who refuse pregnancy test.
• lack of consent to participate in the study.
• surgical tracheotomy.
• Involvement of the larynx (above the first tracheal brace).

Patients after successfull respiratory weaning with symptomatic trachealstenosis