THE VISCERAL BRANCHES. 797 



pepsia and vomiting directly from pressure upon the stomach, and indirectly from 

 involvement of the solar plexus. 5. Jauyidice from compression of the common 

 duct and duodenum. 6. Polyuria followed by albuminuria and hcBmaturia or anuria 

 from pressure on the renal nerves. 7. (Edema of the legs and feet from pressure on 

 the ascending cava. If the tumor enlarges posteriorly there is apt to be also : 

 8. Pain in the buttocks, thighs, and loins from pressure on the lumbar nerves, and 

 in the back from pressure on the solar plexus and splanchnics, or from erosion of the 

 vertebra ; and rarely there may be : 9. Weakness or paralysis of the lower extremities 

 from involvement of the cord. As a rule, the pain, distress, and disability are not so 

 great in abdominal as in thoracic aneurism, because of the greater mobility of the 

 abdominal contents, which can be much more easily displaced than those of the 

 middle or posterior mediastinum and with consequences not so directly threatening Ufe. 



Abdominal aneurisms rupture into the retroperitoneal space, the peritoneal 

 cavity, the intestines (most often the duodenum), or — after ulcerating through the 

 diaphragm — into the pleura. 



Compression of the abdominal aorta may be effected by special tourniquets, the 

 intestines being first well emptied and then got out of the way, as far as possible, 

 by rolling the patient on the right side before applying the pad, between which and 

 the skin a soft sponge should be interposed. The pad is placed a little to the left 

 of the umbilicus, or, better — as the aorta may be median in position — directly over 

 the pulsation of the vessel. Macewen has effectively controlled the abdominal aorta 

 by throwing the weight of the body on the aorta through the closed right hand placed 

 a little to the left of the middle line, the knuckle of the index-linger just touching 

 the upper border of the umbilicus. With the left hand the arrest of the blood-cur- 

 rent is ascertained by feeling the femoral at the brim of the pelvis. Only enough 

 weight to arrest the femoral pulse is required. If the patient vomits or coughs, the 

 pressure must be increased, lest the hand be lifted from the aorta by the abdominal 

 muscles. 



Of course these methods would be applicable only to aneurisms situated near 

 the bifurcation. Compression has cured at least one such case. They have, how- 

 ever, been applied in iliac and common femoral aneurism and to control hemorrhage 

 during inter-ilio-abdominal or hip-joint amputation. 



Ligation of the abdominal aorta has been done in about a dozen cases with 

 uniformly fatal results. The ligature has been applied between the bifurcation and the 

 origin of the inferior mesenteric artery — one and a half to two inches higher. A median 

 incision with its centre at the umbilicus is made, the peritoneal cavity opened, and 

 the intestines displaced. The layer of peritoneum over the artery is carefully divided 

 — or scratched through — and the vessel isolated, avoiding the sympathetic fibres 

 connecting the aortic plexus (lying above the origin of the inferior mesenteric) 

 with the hypogastric plexus (lying between the common iliacs) (Astley Cooper, 

 Jacobson). The dense areolar tissue surrounding the vessel is penetrated and the 

 aneurism needle is passed through it from right to left to avoid injury to the vena 

 cava. The extraperitoneal operation closely resembles that for ligation of the common 

 iliac (page 808). 



THE VISCERAL BRANCHES. 



I. The Coeliac Axis. — The coeliac axis (a. coeliaca) (Figs. 720, 721) arises 



' from the anterior surface of the abdominal aorta, a short distance below the aortic 



opening of the diaphragm, and is a short, stout trunk from 1-1.5 cm. in length, 



which projects forward above the upper border of the pancreas. It terminates by 



dividing simultaneously into (i) \k^& gastric, (2) hepatic, and (3) splenic arteries. 



Variations. — The coeliac axis may be wanting, the three branches to which normally it 

 gives origin arising independently from the aorta. Occasionally it gives rise to but two terminal 

 branches, usually the hepatic and splenic, although more rarely they may be the gastric and 

 splenic ; or, while dividing into three terminal branches, these may be the gastric, hepatic, and 

 a common stem from the two inferior phrenics ; the gastric, splenic, and the right suprarenal ; 

 or the gastric, splenic, and the right gastro-epiploic. It may also give rise to additional branches, 

 such as one or both of the inferior phrenics, a gastro-duodenal, the superior mesenteric, the 

 colica media, or the pancreatica magna, this last being normally a branch of the splenic artery. 



