Treatment Alternatives in iSGS (NoAAC PR-02 Study)


The study is aimed at answering the questions; (1) How well do the most commonly used treatments in iSGS work? and (2) What quality-of-life trade-offs are associated with each approach?

With the results of this trial, the investigators hope to provide information to iSGS patients: (1) Given my personal characteristics, conditions, and preferences, what should I expect will happen to me? and (2) What are my options, and what are the potential benefits and harms of these options?

Full Title of Study: “Treatment Alternatives in Adult Rare Disease; Assessment of Options in Idiopathic Subglottic Stenosis North American Airway Collaborative PR-02 Study (NoAAC PR-02 Study)”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: December 2020

Detailed Description

Idiopathic subglottic stenosis (iSGS) is a rare disease in which the trachea narrows for no known reason. Although uncommon (with an estimated incidence of 1:400,000 persons per year), both the disease and its therapies profoundly affect patients' ability to breathe, communicate and swallow. Breathing difficulties (i.e. dyspnea) is the hallmark symptom and the primary cause of death and disability. However, patients can also experience debilitating voice changes and swallowing problems due to the condition or its treatment.

People with this disease often require several surgeries per year. A variety of treatments have been advanced to manage iSGS but are generally categorized into: 1) endoscopic dilation of the tracheal stenosis (accomplished with rigid instruments or inflatable balloons); 2) endoscopic resection of the stenosis (with prolonged medical therapy after surgery); or 3) open neck surgery with resection of the affected tracheal segment with end-to-end anastomosis. Each patient can require repeated surgeries to keep their trachea open, which increases odds of treatment side effects and complications. All approaches have unique and often disabling associated side effects, which can significantly affect a patient's quality of life.

Because the disease is rare, it is difficult for patients to find good information so that they can understand the spectrum of treatment options. This is particularly difficult because most patients present with severe breathing trouble and need treatment quickly, limiting their ability to explore options. Additionally, there is a general lack of high-quality, reliable, and accessible data to inform individual patient decision-making. Imperfect information and limited evidence on treatment outcomes complicate patient decision-making as they try to balance survival, symptoms, and quality of life considerations.

Beyond the gaps in understanding the relative effectiveness of the different treatments available, no studies have explored functional outcomes in iSGS (i.e. how well patients breathe, speak, and swallow after treatments). These endpoints are important to patients and are arguably a primary determinant in decision-making. Direct engagement with patients is critical to understand these quality of life considerations, since patient and physician perspectives aren't always the same. For example, results show that endoscopic dilation is associated with a higher rate of disease recurrence and thus need for repeated surgery. Meanwhile, open tracheal resection is a major surgery with significant immediate perioperative risks and has been associated with alterations in voice and swallowing. Open tracheal resection appears to reduce the risk of disease recurrence, but the degree of benefit, and the trade-offs associated with this approach are unanswered questions.

The proposed study from the North American Airway Collaborative (NoAAC PR- 02) is designed to fill this void. Our prospective study will directly compare the effectiveness of standard of care treatments and assess their associated quality of life tradeoffs in iSGS patients.


  • Procedure: Endoscopic dilation of subglottic stenosis
    • This is accomplished with rigid instruments or inflatable balloons.
  • Procedure: Endoscopic resection of the stenosis
    • This is accomplished with C02 lasers and paired with prolonged medical therapy after surgery.
  • Procedure: Tracheal Resection
    • Resection of the affected tracheal segment with end-to-end anastomosis

Arms, Groups and Cohorts

  • iSGS patients
    • Participants will receive standard of care treatment at the respective center and will be followed longitudinally for symptom changes, need for further treatment, complications, and will have Patient-reported outcomes (PROs) administered at a priori determined intervals.

Clinical Trial Outcome Measures

Primary Measures

  • Treatment Effectiveness: Time to recurrent procedure
    • Time Frame: 3 years
  • Treatment Effectiveness: Need for tracheostomy
    • Time Frame: 3 years

Secondary Measures

  • QOL
    • Time Frame: 3 years
    • Patient quality of life assessment: voice (VHI-10)
  • QOL
    • Time Frame: 3 years
    • Patient quality of life assessment: dysphagia (EAT-10)
  • QOL
    • Time Frame: 3 years
    • Patient quality of life assessment: breathing (COPD dyspnea)
  • QOL
    • Time Frame: 3 years
    • Patient quality of life assessment: general quality of life (SF-12)
  • Patient Reported Outcome
    • Time Frame: 3 years
    • Non-traditional PRO focused on social support
  • Patient Reported Outcome
    • Time Frame: 3 years
    • Non-traditional PRO focused on fear of disease recurrence
  • Patient Reported Outcome
    • Time Frame: 3 years
    • Non-traditional PRO focused on disease anxiety and burden
  • Patient Reported Outcome
    • Time Frame: 3 years
    • Non-traditional PRO focused on participatory decision-making style

Participating in This Clinical Trial

Inclusion Criteria

  • Greater than 18 years of age.
  • The lesion must involve the subglottis.

Exclusion Criteria

  • Less than 18 years of age
  • Patients without capacity to consent for themselves
  • History of significant laryngotracheal traumatic injury.
  • History of endotracheal intubation or tracheotomy within 2 years of presentation.
  • Major anterior neck surgery.
  • History of neck irradiation.
  • History of caustic or thermal injuries to the laryngotracheal complex.
  • History of a clinically diagnosed vasculitis or collage vascular disease.
  • Positive antinuclear cytoplasmic antibody titers.

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Vanderbilt University Medical Center
  • Collaborator
    • Patient-Centered Outcomes Research Institute
  • Provider of Information About this Clinical Study
    • Principal Investigator: Alexander Gelbard, MD, Assistant Professor, Department of Otolaryngology – Vanderbilt University Medical Center
  • Overall Official(s)
    • Alexander Gelbard, MD, Principal Investigator, Vanderbilt University Medical Center
    • David O. Francis, MD, MS, Study Chair, Vanderbilt University Medical Center

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