Arteries of the stomach and colon

 

 

The celiac artery is a short thick trunk, about 1.25 cm. in length, which arises from the front of the aorta, just below the aortic hiatus of the diaphragm, and, passing nearly horizontally forward, divides into three large branches, the left gastric, the hepatic, and the splenic; it occasionally gives off one of the inferior phrenic arteries.

 

The celiac artery and its branches; the liver has been raised, and the lesser omentum and anterior layer of the greater omentum removed

Relations.

          The celiac artery is covered by the lesser omentum. On the right side it is in relation with the right celiac ganglion and the caudate process of the liver; on the left side, with the left celiac ganglion and the cardiac end of the stomach. Below, it is in relation to the upper border of the pancreas, and the lienal vein. 

 

The Left Gastric Artery (a. gastrica sinistra; gastric or coronary artery), the smallest of the three branches of the celiac artery, passes upward and to the left, posterior to the omental bursa, to the cardiac orifice of the stomach. Here it distributes branches to the esophagus, which anastomose with the aortic esophageal arteries; others supply the cardiac part of the stomach, anastomosing with branches of the lienal artery. It then runs from left to right, along the lesser curvature of the stomach to the pylorus, between the layers of the lesser omentum; it gives branches to both surfaces of the stomach and anastomoses with the right gastric artery.

 

The Hepatic Artery (a. hepatica) in the adult is intermediate in size between the left gastric and lienal; in the fetus, it is the largest of the three branches of the celiac artery. It is first directed forward and to the right, to the upper margin of the superior part of the duodenum, forming the lower boundary of the epiploic foramen (foramen of Winslow). It then crosses the portal vein anteriorly and ascends between the layers of the lesser omentum, and in front of the epiploic foramen, to the porta hepatis, where it divides into two branches, right and left, which supply the corresponding lobes of the liver, accompanying the ramifications of the portal vein and hepatic ducts. The hepatic artery, in its course along the right border of the lesser omentum, is in relation with the common bile-duct and portal vein, the duct lying to the right of the artery, and the vein behind. 

 

Its branches are:

  1. Right Gastric,

  2. Cystic, and

  3. Gastroduodenal (which divides into Right Gastroepiploic and Superior Pancreaticoduodenal.

 

The right gastric artery (a. gastrica dextra; pyloric artery) arises from the hepatic, above the pylorus, descends to the pyloric end of the stomach, and passes from right to left along its lesser curvature, supplying it with branches, and anastomosing with the left gastric artery.

 

 The celiac artery and its branches; the stomach has been raised and the peritoneum removed

The gastroduodenal artery (a. gastroduodenalis) is a short but large branch, which descends, near the pylorus, between the superior part of the duodenum and the neck of the pancreas, and divides at the lower border of the duodenum into two branches, the right gastroepiploic and the superior pancreaticoduodenal. Previous to its division it gives off two or three small branches to the pyloric end of the stomach and to the pancreas.

 

The right gastroepiploic artery (a. gastroepiploica dextra) runs from right to left along the greater curvature of the stomach, between the layers of the greater omentum, anastomosing with the left gastroepiploic branch of the lienal artery. Except at the pylorus where it is in contact with the stomach, it lies about a finger's breadth from the greater curvature. This vessel gives off numerous branches, some of which ascend to supply both surfaces of the stomach, while others descend to supply the greater omentum and anastomose with branches of the middle colic.

 

The superior pancreaticoduodenal artery (a. pancreaticoduodenalis superior) descends between the contiguous margins of the duodenum and pancreas. It supplies both these organs, and anastomoses with the inferior pancreaticoduodenal branch of the superior mesenteric artery, and with the pancreatic branches of the lienal artery.

 

The cystic artery (a. cystica) usually a branch of the right hepatic, passes downward and forward along the neck of the gall-bladder, and divides into two branches, one of which ramifies on the free surface, the other on the attached surface of the gall-bladder.

 

The Lienal or Splenic Artery (a. lienalis), the largest branch of the celiac artery, is remarkable for the tortuosity of its course. It passes horizontally to the left side, behind the stomach and the omental bursa of the peritoneum, and along the upper border of the pancreas, accompanied by the lienal vein, which lies below it; it crosses in front of the upper part of the left kidney, and, on arriving near the spleen, divides into branches, some of which enter the hilus of that organ between the two layers of the phrenicolienal ligament to be distributed to the tissues of the spleen; some are given to the pancreas, while others pass to the greater curvature of the stomach between the layers of the gastrolienal ligament.

Its branches are:

  1. Pancreatic,

  2. Short Gastric, and

  3. Left Gastroepiploic

 

The pancreatic branches (rami pancreatici) are numerous small vessels derived from the lienal as it runs behind the upper border of the pancreas, supplying its body and tail. One of these, larger than the rest, is sometimes given off near the tail of the pancreas; it runs from left to right near the posterior surface of the gland, following the course of the pancreatic duct, and is called the arteria pancreatica magna. These vessels anastomose with the pancreatic branches of the pancreaticoduodenal and superior mesenteric arteries.

 

The short gastric arteries (aa. gastricæ breves; vasa brevia) consist of from five to seven small branches, which arise from the end of the lienal artery, and from its terminal divisions. They pass from left to right, between the layers of the gastrolienal ligament, and are distributed to the greater curvature of the stomach, anastomosing with branches of the left gastric and left gastroepiploic arteries.

 

The left gastroepiploic artery (a. gastroepiploica sinistra) the largest branch of the lienal, runs from left to right about a finger’s breadth or more from the greater curvature of the stomach, between the layers of the greater omentum, and anastomoses with the right gastroepiploic. In its course it distributes several ascending branches to both surfaces of the stomach; others descend to supply the greater omentum and anastomose with branches of the middle colic.

 

 The superior mesenteric artery and its branches

The superior mesenteric artery (a. mesenterica superior) is a large vessel which supplies the whole length of the small intestine, except the superior part of the duodenum; it also supplies the cecum and the ascending part of the colon and about one-half of the transverse part of the colon. It arises from the front of the aorta, about 1.25 cm. below the celiac artery, and is crossed at its origin by the lienal vein and the neck of the pancreas. It passes downward and forward, anterior to the processus uncinatus of the head of the pancreas and inferior part of the duodenum, and descends between the layers of the mesentery to the right iliac fossa, where, considerably diminished in size, it anastomoses with one of its own branches, viz., the ileocolic. In its course it crosses in front of the inferior vena cava, the right ureter and Psoas major, and forms an arch, the convexity of which is directed foward and downward to the left side, the concavity backward and upward to the right. It is accompanied by the superior mesenteric vein, which lies to its right side, and it is surrounded by the superior mesenteric plexus of nerves.

Its branches are:

  1. Inferior Pancreaticoduodenal,

  2. Ileocolic, Intestinal,

  3. Right Colic, and

  4. Middle Colic.

 

The Inferior Pancreaticoduodenal Artery (a. pancreaticoduodenalis inferior) is given off from the superior mesenteric or from its first intestinal branch, opposite the upper border of the inferior part of the duodenum. It courses to the right between the head of the pancreas and duodenum, and then ascends to anastomose with the superior pancreaticoduodenal artery. It distributes branches to the head of the pancreas and to the descending and inferior parts of the duodenum.

 

The Intestinal Arteries (aa. intestinales; vasa intestini tenuis) arise from the convex side of the superior mesenteric artery. They are usually from twelve to fifteen in number, and are distributed to the jejunum and ileum. They run nearly parallel with one another between the layers of the mesentery, each vessel dividing into two branches, which unite with adjacent branches, forming a series of arches, the convexities of which are directed toward the intestine From this first set of arches branches arise, which unite with similar branches from above and below and thus a second series of arches is formed; from the lower branches of the artery, a third, a fourth, or even a fifth series of arches may be formed, diminishing in size the nearer they approach the intestine. In the short, upper part of the mesentery only one set of arches exists, but as the depth of the mesentery increases, second, third, fourth, or even fifth groups are developed. From the terminal arches numerous small straight vessels arise which encircle the intestine, upon which they are distributed, ramifying between its coats. From the intestinal arteries small branches are given off to the lymph glands and other structures between the layers of the mesentery.

 

The Ileocolic Artery (a. ileocolica) is the lowest branch arising from the concavity of the superior mesenteric artery. It passes downward and to the right behind the peritoneum toward the right iliac fossa, where it divides into a superior and an inferior branch; the inferior anastomoses with the end of the superior mesenteric artery, the superior with the right colic artery.

The inferior branch of the ileocolic runs toward the upper border of the ileocolic junction and supplies the following branches

(a)    colic, which pass upward on the ascending colon;

(b)   anterior and posterior cecal, which are distributed to the front and back of the cecum;

(c)    an appendicular artery, which descends behind the termination of the ileum and enters the mesenteriole of the vermiform process; it runs near the free margin of this mesenteriole and ends in branches which supply the vermiform process; and

(d) ileal, which run upward and to the left on the lower part of the ileum, and anastomose with the termination of the superior mesenteric.

 

The Right Colic Artery (a. colica dextra) arises from about the middle of the concavity of the superior mesenteric artery, or from a stem common to it and the ileocolic. It passes to the right behind the peritoneum, and in front of the right internal spermatic or ovarian vessels, the right ureter and the Psoas major, toward the middle of the ascending colon; sometimes the vessel lies at a higher level, and crosses the descending part of the duodenum and the lower end of the right kidney. At the colon it divides into a descending branch, which anastomoses with the ileocolic, and an ascending branch, which anastomoses with the middle colic. These branches form arches, from the convexity of which vessels are distributed to the ascending colon.

 

The Middle Colic Artery (a. colica media) arises from the superior mesenteric just below the pancreas and, passing downward and forward between the layers of the transverse mesocolon, divides into two branches, right and left; the former anastomoses with the right colic; the latter with the left colic, a branch of the inferior mesenteric. The arches thus formed are placed about two fingers’ breadth from the transverse colon, to which they distribute branches.

 

 The inferior mesenteric artery and its branches

The inferior mesenteric artery (a. mesenterica inferior) supplies the left half of the transverse part of the colon, the whole of the descending and iliac parts of the colon, the sigmoid colon, and the greater part of the rectum. It is smaller than the superior mesenteric, and arises from the aorta, about 3 or 4 cm. above its division into the common iliacs and close to the lower border of the inferior part of the duodenum. It passes downward posterior to the peritoneum, lying at first anterior to and then on the left side of the aorta. It crosses the left common iliac artery and is continued into the lesser pelvis under the name of the superior hemorrhoidal artery, which descends between the two layers of the sigmoid mesocolon and ends on the upper part of the rectum.

Its branches are:

  1. Left Colic,

  2. Sigmoid and

  3. Superior Hemorrhoidal.

 

The Left Colic Artery (a. colica sinistra) runs to the left behind the peritoneum and in front of the Psoas major, and after a short, but variable, course divides into an ascending and a descending branch; the stem of the artery or its branches cross the left ureter and left internal spermatic vessels. The ascending branch crosses in front of the left kidney and ends, between the two layers of the transverse mesocolon, by anastomosing with the middle colic artery; the descending branch anastomoses with the highest sigmoid artery. From the arches formed by these anastomoses branches are distributed to the descending colon and the left part of the transverse colon.

 

The Sigmoid Arteries (aa. sigmoideæ) two or three in number, run obliquely downward and to the left behind the peritoneum and in front of the Psoas major, ureter, and internal spermatic vessels. Their branches supply the lower part of the descending colon, the iliac colon, and the sigmoid or pelvic colon; anastomosing above with the left colic, and below with the superior hemorrhoidal artery.

 

 Sigmoid colon and rectum, showing distribution of branches of inferior mesenteric artery and their anastomoses

The Superior Hemorrhoidal Artery (a. hæmorrhoidalis superior) the continuation of the inferior mesenteric, descends into the pelvis between the layers of the mesentery of the sigmoid colon, crossing, in its course, the left common iliac vessels. It divides, opposite the third sacral vertebra, into two branches, which descend one on either side of the rectum, and about 10 or 12 cm. from the anus break up into several small branches. These pierce the muscular coat of the bowel and run downward, as straight vessels, placed at regular intervals from each other in the wall of the gut between its muscular and mucous coats, to the level of the Sphincter ani internus; here they form a series of loops around the lower end of the rectum, and communicate with the middle hemorrhoidal branches of the hypogastric, and with the inferior hemorrhoidal branches of the internal pudendal.