(1)
IMM, Curie-Montsouris Thorax Institute, Paris, France
Electronic Supplementary Material
The online version of this chapter (doi:10.1007/978-3-319-55901-8_8) contains supplementary material, which is available to authorized users.
On the right side, S2 and S1+2 and segmentectomies are frequently indicated as the location of a tumor or a nodule in S2 or at the border between S2 and S1 is not unusual. Preserving S3, rather than performing an upper lobectomy, has two advantages: this spares respiratory function and S3 is a large segment that occupies the pleural cavity and prevents reexpansion issues that can be encountered after an upper lobectomy.
8.1 Anatomical Landmarks (◘ Fig. 8.1)
Bronchus
As it enters the parenchyma, the upper lobe bronchus triplicates into three segmental bronchi: apical (B1), posterior (B2), and anterior (B3). B1 and B2 can originate separately or as a common trunk (B1+2) (◘ Fig. 8.1a).
Fig. 8.1
Anatomical landmarks. a segmental bronchi and arteries (posterior view), b arterial supply to the apicoposterior segments (posterior view), c venous drainage (anterior view), d V2t crossing the posterior aspect of Asc.A2 (view from above)
Arteries
The arteries to the apical and posterior segments have to be divided. They arise from the truncus anterior and from the PA in the fissure (ascending arteries). The truncus anterior duplicates into two branches: the apical artery A1 and the anterior artery A3 that must be preserved. The posterior segment is supplied by the ascending A2 (Asc.A2) that originates within the fissure from the posterior aspect of the pulmonary artery, opposite to the middle lobe artery. It ascends to S2 and lies posteriorly to the lobar bronchus. In the majority of patients, there is only one artery, while there are none or two in some patients (◘ Fig. 8.1b).
In many patients, a branch of A1 supplies S2 and is named recurrent A2 (Rec.A2). It usually runs along the bronchus.
Veins
In most cases, the segmental veins of the upper lobe are the two upper tributaries of the upper lobe vein:
V1 is the uppermost branch and is found in the hilum of the upper lobe. It is the most anterior and superior vessel.
V2+3 is the central vein and runs in the parenchyma and within the fissure. It gives a large posterior branch for V2 and small tributaries for V3 (◘ Fig. 8.1c).
8.2 Variations and Pitfalls
When there are two ascending A2, the most anterior one must not be mistaken for an anterior ascending branch (A3) which supplies the anterior segment.
When present, the recurrent A2 can be a danger during dissection of B1 or B2.
In about 10% of patients, the ascending A2 artery originates from the superior supply of the lower lobe or forms a common trunk with A6.
A small vein draining S2 frequently cross the posterior aspect of the ascending A2 and must be severed before dissecting this artery (◘ Fig. 8.1d).
During a posterior approach, i.e., the technique described here, B2 can be mistaken for B1+2 if B1 and B2 are independent and if both bronchi are short (B1 will appear once B2 is stapled).
8.3 Technique
8.3.1 Fissure and Ascending Posterior Artery
As for right upper lobectomies, it is more convenient to start the resection by controlling and dividing the bronchi. However, this can be done only if the ascending posterior artery, which hides the upper lobe bronchus, is severed. The posterior aspect of the oblique fissure is opened as described for right upper lobectomies (see page 52) (◘ Fig. 8.2).
