Study: NCT04620343

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: A: Breathing advice with bio-feedback
Description: Information and breathing advice with biofeedback will serve as an active comparator in this study, and time allowed for IBA and biofeedback in this study will be max 30 min. The teaching will be provided by the attending physician and the test leader. The session will follow a strict checklist. After the laryngoscope has been secured in correct position the patient will be shown his/her larynx on the screen, providing the patient with basic knowledge on laryngeal anatomy and function in a calm atmosphere before the CLE-test. After, the patients will be trained to make any symptoms abate, and a good breathing posture and how to optimally use their breathing muscles.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: B: Breathing advice with bio-feedback, Inspiratory muscle training (IMT)
Description: Breathing advise and IMT. The inspiratory muscle training (IMT) will build on the information the patients have obtained during the IBA and biofeedback session. The IMT will focus on training endurance and coordination of the PCA muscle, aiming to reduce fatigue of the abducting capacity of the larynx and to enhance coordination and create a sense of laryngeal control. When performing the IMT sessions, it is of utmost importance that a functional diaphragmatic breathing pattern has been established, and that this breathing pattern is maintained throughout all the IMT sessions. Once the patient has demonstrated that he/she is able to perform breathing according to these principles, the IMT session will follow a detailed protocol while wearing a flexible laryngoscope and settings and techniques are adjusted to ensure max open larynx. The patient will perform IMT training at home as instructed and have video meetings one and three weeks after initial training to observe progress.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: C: Breathing advice with bio-feedback, Speech Therapy
Description: The training period with the speech therapist takes three days, divided into 6 sessions. The training is continued at home, implementing the techniques during physical activity and at rest. The aim of the speech therapy is to help the patients to develop a strategy on how to control his/her larynx during exercise, and to be able to continue exercising without experiencing dramatic EILO incidents. They will be informed that the best approach is to start practicing while performing low to moderate intensity exercise, and then gradually increase the intensity as they become more confident. It will be emphasized that the new breathing technique they are about to adopt will need to be repeated until it becomes adapted as a part of their automated breathing pattern. Patients will be followed up with video meetings one and three weeks after initial training to observe progress.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: D: Breathing advice with bio-feedback, IMT and Speech Therapy
Description: All treatments as described above.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: A: If CLE-test unchanged, additional IMT and Speech Therapy
Description: All treatments as described above.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Surgery 1: Supraglottoplasty - full procedure under general anesthesia
Description: Endoscopic supraglottoplasty with carbon dioxide laser and cold steel microlaryngeal instruments. The patient is intubated with an armored laser-tube which is positioned in the posterior midline to protect this area from laser injury. The laryngoscope is positioned into the vallecula and the surgery is visualized through an operation-microscope. CO2-laser beams of 2-4W focused with micro spot is utilized. Releasing incisions are made at the anterior border of both AEFs. The depth of the incisions are limited to the cranial border of the ventricular folds. The cuneiform tubercles including their surrounding mucosa are removed in a circular pattern before the two incisions are adjoined, thus creating a drop shaped excision. Care is taken to avoid scarring. It is recommended to protect the posterior commissure and the piriform sinus with wet tissue cloths. In case of perioperative edema of the laryngeal mucosa, corticosteroids are administrated to prevent laryngeal edema post-operatively.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Surgery 2: Supraglottoplasty - mini-invasive procedure under general anesthesia
Description: Endoscopic supraglottoplasty with carbon dioxide laser. The patients are intubated with an armored laser-tube, which is positioned in the posterior midline to protect this area from laser injury. The laryngoscope (Benjamin/Lindholm) is positioned into the vallecula and the surgery is visualized through an operation-microscope. CO2-laser beams of 2-4W focused with micro spot are utilized. Four punctures will be made along the lateral borders of both aryepiglottic folds bilateral, thus creating a row of small punctures parallel to the rim of the aryepiglottic folds. The punctions should not be deeper than the incision in the full procedure (above); i.e. less than 5 millimeter, and care must be taken to avoid heat affecting the nervus recurrens posteriorly. Care is taken to avoid scarring and collateral thermal injury. It is recommended to protect the posterior commissure and the piriform sinus with wet tissue cloths. No antibiotic prophylaxis is administered.