An anatomical and surgical study of the extra-thoracic fascia.

Under the title of "Fascia Exo-Thoracique," Gabrielle, Latarjet, and Michaud (1947) have described an extremely thin, homogeneous, and continuous fascial layer which covers the surface of the thoracic cage, posteriorly and laterally. This is a well-known surgical fact and is frequently used in suturing the resulting costo-intercostal incisions of thoracotomies. However, the literature does not effectively describe this fascia either in the sense of its possessing recognizable morphological characteristics, or those histological properties which render valuable service to the thoracic surgeon. The classical papers, French, English, American or German, describe a plane of cleavage interposed between a posterior muscular plane (levator scapulae, rhomboids, and serratus magnus) and the costo-intercostal surface anteriorly. Furthermore, this space was supposedly brought into existence by the incessant movements of the scapula upon the thoracic wall. This gave birth to the idea of a pseudo-articulation which was described and called the "l'articulation scapulothoracique" by Miramond de Laroquette (1909). It has since remained the classical description. This study will show that the interposed space is bounded by two layers: one is posterior and covers the anterior surface of the rhomboids and the serratus magnus; the second is anterior and rests upon the costo-intercostal surface. This second layer will henceforth be referred to as the " extra-thoracic fascia" by analogy with the "endo-thoracic fascia" which is interposed between the parietal pleura and the costo-intercostal surface.