Figure 1:

The fissures are described as follows. In the right lung: upper–lower is the fissure separation for upper lobectomy, for lower lobectomy and for upper and middle bilobectomy; upper–middle is for upper lobectomy and for middle lobectomy; and lower–middle is for lower lobectomy and for middle lobectomy. In the left lung: upper is for the fissure separation between the upper segment of the upper lobe (S1 + 2) and the apical segment of the lower lobe (S6); and lower is between the lingular (S4,5) segment and segment S8.