Mohammad Samet - M.D, Assistant Professor of Pulmonology Department of Pulmonology, School ofMedicine, Shahid Sadoughi University of Medical Sciences,Yazd, Iran

The central airways are defined as those airways that can be directly visualized by flexibletherapeutic bronchoscopy with an outer diameter of 5–6 mm. The central airways are limited to thetrachea , main stem bronchi and lobar bronchi. Central airway obstraction (CAO) can be classifiedinto two distinct patterns :ü focal airway obstructionü diffuse airway narrowingthey are splited into malignant and non malignant diseases . CT and bronchoscopy arenecessary techniques that play an important role in the evaluation , diagnosis and treatmentplanning for a CAO.Techniques for malignant central airway recanalisationFocal CAO can be classified into three types of obstruction:· purely intraluminal tumour growth· purely extraluminal tumour compression· combination of bothThese are typically managed with a multimodal approach focusing on an immediate or adelayed effect , comprising mechanical debulking , heat or cold thermotherapy and airway stentingwhen appropriate .A typical interventional pulmonology algorithm for central airway recanalisationencompasses the following five phases:1. Ask question whether asymptomatic stenosis is present and/or palliation is required2. Identify the cause ,morphology , extent and mechanism of the central airway narrowingtogether with confirmation of patent distal airways. 3. Treat the intraluminal component when present4. Assess the residual degree of airway narrowing5. Treat the residual stenosis and /or mural component when considered appropriate