The assessment of airway caliber for the management of bronchial obstructing lesions, before stent placement, is gaining more importance. The length assessment of the narrowed segment is easily measured over the shaft of the scope, but the problematic part remains in the diameter assessment. This new technique accurately estimates the diameter of the bronchus where stenting will be attempted.
This new method for assessing the diameter relies on using a biopsy forceps of known diameter (i.e., 2.2 mm) and passing it through the working channel of the scope to the desired level which we want to know the diameter. We record this frame on any capturing device for further processing. After the procedure is over, we transform the snapshot onto commercial photo-processing software (Photoshop). This software has a tool called the measure tool, which is basically similar to the measuring tool on an unltrasound machine, which is capable of measuring the distance between a point “X” and a point “Y” on the screen. Now, the diameter of the biopsy forceps at the desired level of the bronchus is measured using the software, and then divided by the actual diameter (2.2 mm) to obtain the magnification ratio of the videoscope. The desired bronchus diameter is then measured using the measuring tool and then divided by the magnification ratio obtained earlier. This gives the accurate diameter of the airway at the desired level.
This technique has been tried and showed efficacy in different airway problems: endobronchial tumors, post-intubation tracheal stenosis, external compression by enlarged lymph nodes.
This technique ensures accurate assessment of the airway lumen diameter to assure the exact choice of stent size and avoid over or under sizing.
Accurate assesment of the bronchial tree can be done using a simple commercial computer software.
Ahmed Al-Halfawy, No Financial Disclosure Information; No Product/Research Disclosure Information