176 SURGICAL APPLIED ANATOMY. [Chap, x. 



In some cases of long-standing empyema with 

 open sinus all that part of the bony wall of the thorax 

 which corresponds to the outer boundary of the 

 suppurating cavity is removed in order that the cavity 

 may collapse and be in a position to close. This latter 

 measure is known as Estlander's operation, or thora- 

 coplasty. In some instances portions of as many as 

 nine ribs have been excised, and the total length of 

 bone removed has reached 50 to 60 inches. 



In removing a rib the bone is entirely bared of 

 periosteum with the rugine, and the excision is extra- 

 periosteal. In this way the intercostal vessels are not 

 exposed, and, if divided subsequently, can be readily 

 secured when the ribs are out of the way. 



The internal mammary artery runs parallel 

 to the border of the sternum, and about half an inch 

 from it. It may give rise to rapidly fatal haemorrhage 

 if wounded. The vessel may readily be secured in 

 the first three intercostal spaces, and with some diffi- 

 culty in the fourth or fifth space. It is most easily 

 reached through the second space, and cannot be 

 secured through any space below the fifth. 



The female breast extends from the third to 

 the fifth rib. It is supported by the superficial 

 pectoral fascia, which divides into two layers to 

 enclose it. The organ is made up of an accumulation 

 of alveolar glands, which open into ducts discharging 

 at the nipple. In cases where during lactation the 

 acini are engorged with milk, the outlines of the 

 several lobules and lobes of the breast are rendered 

 very distinct. The size of the breast depends usually 

 rather upon a deposit of fat collected about the organ 

 and distributed among its lobules than upon a 

 development of true gland tissue. A considerable 

 and rapid development of the mammary gland tissue 

 takes place at puberty, and the breast remains in 

 its most perfect anatomical condition during the 



