Thulium laser therapy: A new tool for central airway obstruction, with applicability near metal stents

<bold>Background:</bold> Multiple medical lasers have been used for central airway obstruction (CAO), Nd: YAG being the most common type. However, it has a deep tissue penetration (upto 1.5mm) with a risk of airway perforation, increased propensity for architectural distortion and airway scarring, and an inability to use in the vicinity of metal stents. The thulium laser (TL), used in urology, with a relatively lesser depth of penetration (0.25mm) helps overcome these drawbacks associated with Nd: YAG laser, and expands utility to metal stents. <bold>Methods:</bold> Bronchoscopic treatment with TL was performed in 27 consecutive patients with CAO amenable to bronchoscopic laser resection at our centre. The clinical details, computed tomography findings, degree of airway obstruction before and after procedure and complications were recorded. <bold>Results:</bold> 27 patients underwent 40 bronchoscopic procedures with TL application (1 procedure, n=18, 2 procedure, n=7, 3 procedure, n=1, 4 procedure n=1). 15 malignant, 6 benign and 6 endobronchial carcinoids were managed with a combination of laser vaporization and coagulation. Bleeding from highly vascular lesions like endobronchial carcinoid was effectively controlled with laser therapy. TL therapy was also effective for ablating tumour tissue and granulation in the vicinity of metallic stents as seen in four cases without complications. <bold>Conclusions:</bold> The thulium laser is a new generation, low penetration, precise laser, which is a safer and effective modality of treatment for CAO as compared to prior generation lasers. A low penetration allows use adjacent to metal stents, which offers significant advantage