1198 THE SURGICAL ANATOMY OF HERNIA. 



Its posterior wall is formed by a continuation downward of the iliac fascia 

 covering the pubic portion of the fascia lata. 



Its outer wall is formed by the fibrous septum separating it from the inner 

 side of the femoral vein. 



Its inner wall is formed by the junction of the processes of the trans versalis 

 and iliac fasciae, which form the inner side of the femoral sheath, and lies in 

 contact at its commencement with the outer edge of Gimbernat's ligament. 



This canal has two orifices an upper one, the femoral or crural ring, closed 

 by the septum crurale ; and a lower one, the saphenous opening, closed by the 

 cribriform fascia. 



The femoral or crural ring (Fig. 766) is the upper opening of the femoral canal, 

 and leads into the cavity of the abdomen. It is bounded in front by Poupart's 

 ligament and the deep crural arch ; behind, by the os pubis, covered by the Pectineus 

 muscle and the pubic portion of the fascia lata ; internally, by the base of 

 Gimbernat's ligament, the conjoined tendon, the trans versalis fascia, and the 

 deep crural arch ; externally, by the fibrous septum lying on the inner side of the 

 femoral vein. The femoral ring is of an oval form ; its long diameter, directed 

 transversely, measures about half an inch, and it is larger in the female than in 

 the male, which is one of the reasons of the greater frequency of femoral hernia 

 in the former sex. 



Position of Parts around the Ring. The spermatic cord in the male and round 

 ligament in the female lie immediately above the anterior margin of the femoral 

 ring, and may be divided in an operation for femoral hernia if the incision for the 

 relief of the stricture is not of limited extent. In the female this is of little 

 importance, but in the male the spermatic artery and vas deferens may be 

 divided. 



The femoral vein lies on the outer side of the ring. 



The deep epigastric artery in its passage upward and inward from the external 

 iliac artery passes across the upper and outer angle of the crural ring, and is 

 consequently in danger of being wounded if the stricture is divided in a direction 

 upward and outward. 



The communicating branch between the deep epigastric and obturator lies in 

 front of the ring. 



The circumference of the ring is thus seen to be bounded by vessels in every 

 part, excepting internally and behind. It is in the former position that the 

 stricture is divided in cases of strangulated femoral hernia. 



The obturator artery, when it arises by a common trunk with the deep epigastric, 

 which occurs once in every three subjects and a half, bears a very important 

 relation to the crural ring. In some cases it descends on the inner side of the 

 external iliac vein to the obturator foramen, and will consequently lie on the outer 

 side of the crural ring, where there is no danger of its being wounded in the 

 operation for dividing the 'stricture in femoral hernia (see Fig. 373, page 623, 

 fig. A). Occasionally, however, the obturator artery curves along the free margin 

 of Gimbernat's ligament in its passage to the obturator foramen : it would conse- 

 quently skirt along the greater part of the circumference of the crural ring, and 

 could hardly avoid being wounded in the operation (see Fig. 373, page 623, fig. B). 



Septum Crurale. The femoral ring is closed by a layer of condensed areolar 

 tissue called, by J. Cloquet, the septum crurale. This serves as a barrier to the 

 protrusion of a hernia through this part. Its upper surface is slightly concave 

 (fovea femoralis), and supports a small lymphatic gland by which it is separated 

 from the subserous areolar tissue and peritoneum. Its under surface is turned 

 toward the femoral canal. The septum crurale is perforated by numerous aper- 

 tures for the passage of lymphatic vessels connecting the deep inguinal lymphatic 

 glands with those surrounding the external iliac artery. 



The size of the femoral canal, the degree of tension of its orifices, and con- 

 sequently the degree of constriction of a hernia, vary according to the position 

 of the limb. If the leg and thigh are extended, abducted, or everted, the femoral 



