Central airway tumors: interventional bronchoscopy in diagnosis and management

Abstract

The diagnosis of central airway tumors is usually challenging because of the vague presentations.Advances in visualization technology in bronchoscopy aid early detection of bronchial lesion. Cryotechnology has great impact on endobronchial lesion sampling and provides better diagnostic yield. Airway tumor involvements result in significant alteration in life quality and lead to poor life expectancy. Timely and efficiently use ablation techniques by heat or cold energy provide symptoms relief for central airway obstruction. Prostheses implantation is effective in maintaining airway patency after ablative procedure or external compression. Combined interventional bronchoscopy modalities and other adjunctive therapies have improvement in quality of life and further benefit in survival. This review aims to provide a diagnostic approach to central airway tumors and an overview of currently available techniques of interventional bronchoscopy in managing symptomatic central airway obstruction. Here, we provide a clinical review of interventional bronchoscopy in diagnoses and management of central airway tumors. Keywords Diagnostic modalities Computed tomographyOnly less than 30% patients with tracheal tumors have been diagnosed via chest radiography (14). Traditional CT scan is more sensitive and can provide information on the extent of airway lesions. Newly developed multidetector CT (MDCT) can accurately detect airway tumor locations, natures, quantities (1). The extra luminal anatomy is also clearly depicted. Thus, MDCT is a rapid and non-invasive method to provide comprehensive information about the extent of disease process before surgery or interventional bronchoscopy (1). Visualization of bronchoscopyBronchoscopy is the mainstay to approaching endobronchial lesion under direct vision. In addition to conventionally white light bronchoscopy, autofluorescence (AFB) and narrow band imaging (NBI) are new visualization techniques of bronchoscopy which can aid detection of bronchial mucosa lesions (15). Although the specificity of AFB is low and similar to white light bronchoscopy, there is no doubt in usefulness of detecting early bronchial mucosal lesion and evaluate the margin of mucosal involvement (16,17). NBI is designed to detect angiogenesis and neovascular lesion. The diagnostic accuracy is increased under NBI bronchoscopy (15). Both of them have superior sensitivity comparing with white light bronchoscopy [3][4][5]. Endobronchial ultrasonography (EBUS) is also helpful in evaluating the extent of airway lesion involvement (14,18). Tissue sampling: forceps versus cryotechnologyForceps biopsy under direct bronchoscopic vision is the most common method to obtain tissue sample from endobronchial lesion. However, the size of tissue sample is limited by the forceps size. Small samples with crush artifacts are probably insufficient for accurate diagnosis. The diagnostic yield is only 85% of conventional forceps biopsy and patients usually have to repeat bronchoscopy (2,3).Cryotechnology has been used as a t...

Clinical Features and Management of Endobronchial Hamartoma

“…However, in one case(N3), even with the combination of APC and cryotherapy, bronchial stenosis caused by scar hyperplasia occurred. We suspected that scar hyperplasia may be related with [8,9,11,12]. In this study, a patient failed in inserting rigid bronchoscope due to his narrow oropharynx after general anesthesia.…”

“…The snare is placed over the lesion and wrapped around the stem. The stalk is then cut while concurrently providing hemostasis [7,8,9,10]. Snare electrocautery can quickly remove the large tumor in the airway at one time, reducing the treatment time and avoiding multiple complications such as perforation of the airway wall, bleeding and airway burn caused by repeated electrocautery, compared with other electrocautery instruments like forceps, knives or rounded probes.…”

“…APC is complementary to other techniques usually. With its superficial effect on tissue, it is safer to remove the tumor in the airway and can also be used for superficial hemostasis, but it can't avoid the disadvantage of granulation tissue proliferation after treatment [7,8,9,10]. Cryotherapy is based on cytotoxic effects of low temperature on living tissue by repeated freeze thaw cycle, which is both immediate and delayed.…”

“…Because of low water content of cartilage, collagen and poorly vascularized tissue, cryotherapy has less effects on them. So the scarring is minimal and the damage of cartilage is few [8,9,10].…”

Feasibility analysis of flexible bronchoscopy in conjunction with noninvasive ventilation for therapy of hypoxemic patients with Central Airway Obstruction: a retrospective study

“…The syndrome of central airway obstruction(CAO), a common problem in medical and surgical settings (Murgu et al, 2016;Barros Casas et al, 2014), is generally defined as occlusion of >50% of the trachea, mainstem bronchi, bronchus intermedius, or a lobar bronchus. The incidence of this disorder is rising at present, possibly due to (1) the epidemic of lung cancer, which is typically diagnosed at an advanced stage (Guibert et al, 2016) and up to 30% of which causes CAO (Lin & Chung, 2016); (2) the increasing use of artificial airways (Barros Casas et al, 2014); (3) the epidemic of tuberculosis, which is still out of control in parts of the world including Africa and Asia (Dheda et al, 2017). Especially the epidemic of tracheobronchial tuberculosis, which is present in 10%-40% of active pulmonary tuberculosis (Smith, Schillaci & Sarlin, 1987), with involvement of the primary bronchi in 60%-95% of cases (Kashyap, Mohapatra & Saini, 2003).…”