352 The Abdominal Aorta 



forward the liver and suggest hepatic enlargement ; should it impinge 

 against the vena cava, oedema of the legs may occur ; compression of 

 a renal vein may be followed by albuminuria. Briefly, it may be said 

 that if the tumour grow from the back of the aorta the pains are chiefly 

 lumbar ; if from the front the disturbance is chiefly visceral, and the 

 pains are abdominal and epigastric. The aneurysm may leak into the 

 peritoneal cavity, or behind it, forming an enormous, but pulseless, 

 blood-tumour ; or it may burst into the stomach, small intestine, or 

 transverse colon, or, causing absorption of the diaphragm, may enter 

 the chest. 



Ijig-ation of the abdominal aorta may be effected through the 

 linea alba and the peritoneum, by separating the coils of intestine and 

 then gently tearing through the root of the mesentery. Or the vessel 

 may be reached without opening the peritoneum, as for ligation of 

 the common iliac, the pouch being dragged rather further upwards. 

 Should the patient survive, the collateral circulation would be freely 

 established, as described on p. 369, with the additional help of the 

 anastomosis of the lumbar arteries given off below the ligature with 

 those above, and of the inferior mesenteric (should the ligature be 

 placed above that vessel) with the superior mesenteric. 



Branches. The phrenics ascend obliquely over the front of the 

 crura to the vault of the diaphragm, where they anastomose with the 

 internal mammary and intercostal branches. The right phrenic also 

 gives twigs to the liver. 



The cceliac axis arises opposite the top of the first lumbar vertebra, 

 which would place it about four inches above the umbilicus, and just 

 above the pancreas ; it has a semilunar ganglion on either side. It 

 divides into gastric, hepatic, and splenic trunks, of which, in the 

 child, the hepatic is the largest, but, as the proportionate size of the 

 liver decreases, the splenic becomes the largest. 



The gastric (coronary) runs to the left end of the stomach, where 

 it gives branches to the oesophagus, and then doubles on itself to 

 descend in the lesser omentum to the pylorus, where it anastomoses 

 with the hepatic ; at the great end of the stomach it anastomoses with 

 the splenic. 



The hepatic hooks forwards and upwards to reach the portal 

 fissure ; in its ascent in the lesser omentum it has the bile-duct to the 

 right and the vena portae behind. It divides into a right and left 

 trunk, the branches of which enter the lobes together with invest- 

 ments of Glisson's capsule. The right branch gives a twig to tl 

 gall-bladder. The branches of the hepatic are the pyloric to the less 

 curvature of the stomach, to anastomose with the gastric ; and the g 

 tro-duodenal, which, descending behind the first part of the duodenui 

 divides into right gastro-cpiploic (which joins on the great curvatui 

 with the branch from the splenic), and the superior pancreatico-duc 

 denal, which winds round the head of the pancreas. This last-nai 



