An update on advances in interventional bronchoscopy

Because of recent advances, more patients may potentially benefit from a variety of interventional bronchoscopic techniques. Nd:YAG laser phototherapy is the most widely used modality and is the treatment of choice for patients with endobronchial malignancies who have large-central airway obstruction. Cryotherapy may be superior to Nd:YAG phototherapy for more distal airways lesions because of the lower risk of airway perforation, but it may be suboptimal for bulky airways disease that requires quick relief of obstruction. Brachytherapy relieves symptoms, such as cough, dyspnea, and hemoptysis, in many patients who have locally invasive airway malignancies. Endobronchial ultrasonography appears to be a safe and sensitive method for staging lung cancer. In select patients with emphysema, a 1-way endobronchial valve can be used to reduce lung volumes. Bronchial thermoplasty is being studied as a potential treatment for asthma. (J Respir Dis. 2006;27(10):415-428) The role of interventional bronchoscopy continues to expand and now encompasses both malignant and some of the more common nonmalignant respiratory indications. It continues to play an integral part in the multimodality, multidisciplinary management of unresectable endobronchial tumors.1 In the case of primary lung cancer, such a multimodality approach may prolong survival.2 Shea and associates,3 for example, demonstrated improved survival in patients who had unresectable endobronchial squamous cell cancer. However, Cavaliere and Dumon4 have suggested that quality of life may be a more immediate and suitable criterion for assessing the value of an interventional bronchoscopic approach. Recently, lung volume reduction using the endobronchial route has been described, with some promising--albeit early--findings.5 Endobronchial ultrasonography to guide transbronchial needle aspiration appears safe6 and can augment the diagnostic yield.7 In one study, bronchial thermoplasty resulted in reduction of airway smooth muscle mass, which may be of relevance in the treatment of asthma.8 In this article, we review the following techniques in greater detail: Nd:YAG laser phototherapy, argon plasma coagulation and other electrocautery devices, photodynamic therapy, cryotherapy, stents and bronchoplasty, autofluorescence bronchoscopy, endobronchial ultrasonography, endobronchial lung volume reduction techniques, and bronchial thermoplasty.Nd:YAG laser phototherapy Because 75% or more of patients with lung cancer have metastatic spread at the time of diagnosis,9 interventional bronchoscopy should be considered in patients who have endobronchial extension of their disease. These endobronchial tumors tend to be underdiagnosed,1 at least in part because fiberoptic bronchoscopy is not a routine procedure in patients who have lung metastases.10 The unique properties of laser permit its use to heat the endobronchial tumor tissue, resulting in vaporization of or coagulation and hemostasis in this tissue. The Nd:YAG laser is currently the most widely used modality in interventional bronchoscopy. Compared with the carbon dioxide laser, the Nd:YAG laser provides deeper tissue penetration (up to 5 mm), superior photocoagulation, and hemostasis. Although the carbon dioxide laser allows for greater precision, its use is hampered by a shallow tissue penetration of 0.5 mm and the requirement of a rigid bronchoscope.11 Furthermore, the wavelength of the carbon dioxide laser (10,600 nm) precludes its transmission via flexible quartz fiber, necessitating the use of a cumbersome articulated arm system. The wavelength of the Nd:YAG laser (1064 nm) gives rise to its versatility. Because it is transmissible via a flexible quartz fiber, the Nd:YAG laser can be used via either a flexible or a rigid bronchoscope. While rigid bronchoscopy is superior to flexible bronchoscopy for proximal airway endobronchial lesions, flexible bronchoscopy is better for distal lesions.12 Nevertheless, rigid bronchoscopy remains the treatment of choice in patients with respiratory distress and severe endobronchial obstruction by bulky tumors. Rigid bronchoscopy provides the added benefit of allowing simultaneous laser use and suctioning, a