Over the last few years, balloon dilation has been applied to various areas of otolaryngology with mixed success.  Traditional dilation using bougie-type instrumentation was used extensively in the airway from the time of Chevalier Jackson until the 1970's and 1980's when open laryngotracheal reconstruction and microlaryngeal laser use supplanted dilation as the mainstay of therapy for acquired subglottic and tracheal stenosis.  These methods of dilation required sequential dilation with rigid, tapered dilators of increasing size. 

One of the disadvantages of this approach is the application of shear forces to the stenotic area resulting in mucosal injury not only at the site of stenosis, but also in the surrounding tissue.  Proponents of balloon dilation have argued that balloon dilation maximizes the radial forces while minimizing or eliminating shear forces to limit mucosal injury.

Use of balloons as a treatment method for airway stenosis was first reported in a retrospective study from MUSC in the early 1990's as a method for managing tracheal stenosis in children.  After a decade of relative silence on the subject, increasingly common case series and studies have emerged in the otolaryngology literature since 2003. Balloon dilation has been applied with and without adjunctive treatments such as mitomycin C and steroid injection in pediatric patients and adults with stenoses of various etiologies including intubation trauma, Wegener's granulomatosis, and idiopathic subglottic stenosis.

Figure d shows improved airway after dilation.

While the area is still being studied, the consensus is that balloon dilation works best for acquired, short-segment airway stenosis.  Cartilagenous stenosis and long-segment stenosis may not respond as well to balloon dilation.  Dilation of congenital cartilaginous stenosis may result in fracture of the cricoid ring.  Balloon size should be adjusted to the age of the child (generally use a balloon with the same diameter as the outer diameter of an age-appropriate endotracheal tube, +/- 1 mm). 

Balloon dilation has been used successfully for treatment of both acutely developing and mature subglottic stenosis.  This treatment modality may also provide a temporizing measure to improve a patient's airway enough to avoid tracheotomy before a definitive open airway procedure (such as cricotracheal resection) is performed.

The clinical course encountered after balloon dilation typically involves immediate improvement of the stenosis with some degree of restenosis occurring days to weeks after the procedure.  While some patients require only one procedure and remain symptom-free, many patients require multiple dilations over the course of weeks or months to reach maximum benefit.  A limit of four dilations has been suggested as an endpoint to acquire maximum benefit from balloon dilation of airway stenoses, after which other treatment modalities should be considered.

When applied to patients with inflammatory or autoimmune etiologies (i.e. idiopathic or Wegener's granulomatosis), biopsy of the stenosis to confirm diagnosis and rule out malignancy is recommended.  Additionally, direct injection of triamcinolone or a similar long-acting corticosteroid into the area of stenosis may improve long-term outcomes.

In summary, balloon dilation of the airway is an evolving modality that offers the otolaryngologist a treatment option to avoid tracheotomy in patients with subglottic or tracheal stenosis.  Short-term airway improvement is almost always seen after dilation, and long-term improvement occurs frequently although repeat dilations are often necessary.  If airway symptoms are still present after four sessions of dilation, other treatment options should be considered.

Suggested Reading

• Wolter NE, Ooi EH, Witterick IJ. Intralesional corticosteroid injection and dilatation provides effective management of subglottic stenosis in Wegener's granulomatosis. Laryngoscope. 2010 Dec;120(12):2452-5.
• Edmondson NE, Bent J 3rd. Serial intralesional steroid injection combined with balloon dilation as an alternative to open repair of subglottic stenosis. Int J Pediatr Otorhinolaryngol. 2010 Sep;74(9):1078-81. Epub 2010 Jun 17. 
• Rutter MJ, Cohen AP, de Alarcon A. Endoscopic airway management in children. Curr Opin Otolaryngol Head Neck Surg. 2008 Dec;16(6):525-9.