The potential advantages of the thoracoscopic approach include avoiding the morbidity associated with a thoracotomy and better visualisation. Planning and final treatment of the condition may be expedited. For any thoracoscopic procedure, full preparation must be made for thoracotomy in case conversion is required urgently.

The preoperative workup includes careful documentation of the number of lesions and their location using specialised imaging, such as high-resolution CT scanning. Thoracoscopy is most useful for peripheral lesions. CT-guided localisation of deep-seated lesions using a needle technique or wire may be used with radiologic support. However, in some deep-seated lung lesions, thoracotomy may not be avoided.

Single-lung ventilation is ideal; alternatively, insufflation with CO₂ using low flow (1 L/min) and low pressures (4–6 mm Hg in infants and 8–10 mm Hg in older children) may be used. The patient is placed in the lateral decubitus position. For anterior mediastinal lesions, a slight posterior tilt is useful, whereas for a posterior mediastinal lesion, a slight anterior tilt should be considered. The optical port usually is placed in the midaxillary line in the fourth to fifth intercostal space and two other ports are placed one to two spaces above in the posterior (or below the scapular tip) and anterior axillary line for upper-lobe lesions. Working ports for lesions in the lower lobe are placed one to two spaces below in the anterior and posterior axillary line. Port positions are variable and may be best decided after the lesion is identified telescopically. Some surgeons may prefer stab incisions for working instruments (Figs. 5.1, 5.2 and 5.3).