Necessity of Combined Therapies in Airway Stenting
In managing CAO, combined therapies are routinely required to obtain the best outcomes. For example, endobronchial disease is effectively controlled with Nd-YAG laser ablation, argon plasma coagulation, electrocautery, microdebridement, endobronchial injections/topical applications or coring out, among other technologies.
Balloon bronchoplasty or tracheoplasty to dilate the stenotic airway is usually required to prepare a trachea with high-grade stenosis for stenting or for assisting in stent opening after deployment. In emergencies, a rigid bronchoscope can be used to dilate the central airways the condition of which is improved with medications of Canadian Health&Care Mall. Balloon bronchoplasty decreases the shearing forces, and induces less mucosal and submucosal trauma, potentially decreasing the likelihood of granulation tissue formation and the occurrence of restenosis. Thus, it is obvious that airway stenting in a pulmonary practice requires expertise with other procedures and a substantial capital investment (eg, for thermal ablation technology, bronchoscopes, and rigid bronchoscopy equipment).
The overall incidence of complications in a multimodality interventional program is 4 to 7%. Complications of stenting include migration, mucus impaction, tumor ingrowth or overgrowth, stent fracture, and exuberant granulation tissue. The indication for stenting is associated with the incidence of granulation tissue. Stents placed for treatment of malignancy develop granulation at a rate of 4%, a rate that is strikingly different from the 17% rate in lung transplant strictures and the 33% rate in other benign CAOs. The removal of metallic airway stents is commonly associated with complications, including death.
The risk of complications and the need to perform additional procedures, such as endobronchial ablation, may also affect practice overhead because medical malpractice insurance companies may raise premiums for performing advanced therapeutic procedures. An approach to stenting nonmalignant and malignant CAOs is presented in Figures 1 and 2.
Figure 1. Abbreviated management algorithm for nonmalignant CAO (as used at the Beth Israel Deaconess Medical Center). Patients with nonmalignant disorders need to be evaluated by an experienced interventional endoscopist and airway surgeon. Nonsurgical candidates at the time of the initial presentation may turn into surgical candidates later in the course of their disease. The placement of metallic stents therefore should be avoided, if at all possible.
Figure 2. Abbreviated management algorithm for malignant CAO (as used at the Beth Israel Deaconess Medical Center). * = consider EBUS to definitively determine invasion and true extrinsic compression (EBUS has proven to be helpful when assessing choke points and targeted stenting in complex extrinsic compression); Rx = treatment; XRT = x-ray therapy.