The celiac trunk is the first major branch of the abdominal aorta. It originates from the ventral aspect of the aorta at the level of T12–L1 vertebrae and was originally described as an artery that branches into the common hepatic artery, left gastric artery, and splenic artery. Absence of the celiac trunk and origin of the three arteries separately from the aorta is a rare entity that is reported in 0.38% to 2.6% of cases. It is even more uncommon that this variation can be accompanied by other vascular variations of the upper abdomen as accessory arteries to the liver, stomach, and pancreas. These cases arise during embryogenesis due to decreased arterial degeneration combined with decreased arterial fusion, which results in the anatomical variations present in the current case. Complex arterial variations are both a risk for iatrogenic injury during surgical procedures and beneficial during endovascular supply as they may provide additional access for embolization and chemotherapy.

accessory left gastric artery, accessory right hepatic artery, celiac trunk, hepatomesenteric trunk.

The celiac trunk is the first major branch of the abdominal aorta. It originates from the ventral aspect of the aorta at the level of T12–L1 vertebrae and was originally described as an artery that branches into the common hepatic artery, left gastric artery, and splenic artery.^[1] These branches make the celiac trunk the center of arterial supply of the upper abdomen and an important anatomical structure during invasive and mini-invasive procedures. It is important to consider developmental variations of the celiac trunk during various invasive and therapeutic procedures such as surgery of the organs of upper abdomen, endovascular procedures, etc.^[2] Due to the anatomical variations, there have been multiple attempts to classify the anatomy of celiac trunk by Lipshutz (1917), Adachi (1928), Morita (1935) and others.^[3–5] Not all variations have been observed until now and the existence of diverse classifications makes the topic more complicated for both clinical practice and research.^{[1, 2]}

We present an anatomical case report of an absent celiac trunk with the coexistence of various developmental variations of the arterial supply of the upper abdomen.

During dissection of the internal organs of the upper part of the abdominal cavity of a 56-year-old man, we encountered multiple variations of the arterial supply. The celiac trunk was absent and all three vessels began as separate branches from the abdominal aorta. The splenic artery had a diameter of 0.7 cm and originated from the abdominal aorta 1.7 cm below the inferior phrenic artery. A common trunk (0.5 cm in length) that branched into the left gastric artery and superior adrenal artery was located at the same level on the left. The left gastric artery supplied the lesser curvature of the stomach, and the right superior adrenal artery gave off seven short branches to the upper pole of the adrenal gland, as well as a branch to the diaphragm. The common hepatic artery branched and the superior mesenteric artery had a common trunk extending from the aorta 1.8 cm below the splenic artery (Fig. 1).

At a distance of 2.3 cm from the origin of the common hepatic artery, the inferior pancreatic artery branched off, supplying blood to the anterior surface of the pancreatic head. The common hepatic artery continued into the proper hepatic artery, giving off the gastroduodenal artery at the level of the lower edge of the liver, to the right of the caudate lobe, in the region of the neck of the pancreas (Fig. 1).

Figure 1.

1: aorta; 2: splenic artery; 3: common trunk branching into the left gastric artery and the right superior adrenal artery; 4: left gastric artery; 5: superior adrenal artery; 6: inferior phrenic artery; 7: superior mesenteric artery; 8: common hepatic artery; 9: inferior pancreatic artery; 10: gastroduodenal artery; 11: right gastric artery; 12: right gastroepiploic artery; 13: accessory right gastroepiploic artery; 14: pyloric artery; 15: superior anterior pancreatoduodenal artery; 16: head of the pancreas; 17: portal vein; 18: body of the pancreas; 19: greater pancreatic artery; 20: inferior vena cava; 21: left renal vein; 22: left kidney; 23: spleen; 24: stomach (turned away; back surface); 25: liver; 26: gallbladder.

The proper hepatic artery traveled over the portal vein of the liver and had a length of 2.7 cm. In the region of the distal third, it gave off the right gastric artery, and then branched into the left and right hepatic arteries. The left hepatic artery branched into two branches of the first order, the right one provided blood supply mainly to the left lobe of the liver, the second branch (left), 2.2 cm from its beginning, gave off an accessory left gastric artery, then entered the caudate lobe of the liver. The accessory left gastric artery, bending around the upper edge of the posterior part of the liver, divided into two branches. One of them supplied the stomach and did not anastomose with other branches that formed arcades. The other branch provided blood supply to the sphincter and the lower third of the esophagus. The right hepatic artery provided blood supply to the right side of the liver and gallbladder. The cystic artery branched off in the area of the Calo triangle and divided into the anterior and posterior branches in the area of the gallbladder’s neck (Fig. 2).

The gastroduodenal artery ran along the upper edge of the pancreatic head. The artery branched into the superior anterior pancreatoduodenal artery and the superior posterior pancreatoduodenal artery. Two right gastroepiploic arteries and a pyloric artery originated from the superior pancreatoduodenal artery. The right gastroepiploic arteries passed along the greater curvature of the stomach, anastomosing with each other, as well as with the branches of the left gastroepiploic artery extending from one of the branches of the splenic artery. The superior posterior pancreatoduodenal artery, located along the upper edge of the head of the pancreas, immediately branched into three small arteries. The first branch supplied the duodenum. The second bended around the head of the pancreas along its right edge and then entered the posterior surface of the gland. The third branch entered the parenchyma of the gland, traveled 1.7 cm within the gland and then exited from the pancreas dividing into three short thin branches. These three branches entered the parenchyma of the right lobe behind the common bile duct, together with the right hepatic artery. The most medial of them supplied the common bile duct with several small branches (Fig. 2).

Figure 2.

1: proper hepatic artery; 2: right hepatic artery; 3: left gastric artery; 4: right branch of the first order of the left hepatic artery; 5: left branch of the first order of the left hepatic artery; 6: accessory left gastric artery; 7: right gastric artery; 8: left gastric artery; 9: gastroduodenal artery; 10: superior anterior pancreatoduodenal artery; 11: superior posterior pancreatoduodenal artery; 12: the first branch of the superior posterior pancreatoduodenal artery; 13: second branch of the superior posterior pancreatoduodenal artery; 14: the third branch of the superior posterior pancreatoduodenal artery; 15: branches to the right lobe of the liver; 16: cystic artery; 17: head of the pancreas; 18: common bile duct; 19: cystic duct; 20: gallbladder; 21: portal vein; 22: caudate lobe of the liver; 23: the left lobe of the liver; 24: the quadrate lobe of the liver; 25: the right lobe of the liver; 26: the duodenum; 27: body of the pancreas; 28:‌ ‌stomach; 29: esophagus.

The splenic artery had a fairly straight trajectory with one convoluted section, after which it branched into a large pancreatic artery. It, in turn, branched into the left branch, which supplied blood to the body of the pancreas, and the right branch, which gave off branches mainly to the tail of the pancreas. At the level of the distal third, the artery split into two first-order branches, the superior splenic artery of the first order branched into two second-order arteries. Two upper pole arteries branched off from the upper artery of the second order, as well as two short gastric arteries that supplied the posterior surface of the gastric cardia. The left gastroepiploic artery originated at the branching point of the superior splenic artery of the first order and passed along the greater curvature of the stomach, participating in the blood supply to the posterior wall of the stomach and the greater omentum. At a distance of 2.3 cm from its beginning, this artery gave off the second short gastric artery, which also took part in the blood supply to the fundus of the stomach.

The lower splenic artery of the first order gave off two branches of the second order directed to the splenic parenchyma in the area of the hilum (Fig. 3).

Figure 3.

1: splenic artery; 2: lower branch of the splenic artery of the first order; 3: upper branch of the splenic artery of the first order; 4: superior polar arteries; 5: left gastroepiploic artery; 6: short gastric arteries; 7: greater pancreatic artery; 8: branches to the tail of the pancreas; 9: spleen; 10: stomach; 11: pancreatic tail; 12: left kidney; 13: diaphragm.

The superior mesenteric artery branched off from the common hepatomesenteric trunk and descended at a 90° angle, maintaining a straight trajectory. The diameter of the trunk was 2.5 mm in the largest segment. From the left semicircle of the trunk of the superior mesenteric artery, 12 arteries branched to the loops of the jejunum and ileum: seven arteries to the loops of the jejunum, and five arteries to the ileum. The jejunal and ileal arteries formed multiple arcades on their way to the wall of the small intestine. Three-row arcades approached the loops of the jejunum; two rows of arcades were visible in the mesentery of the ileum. These arcades provided smaller branches to the walls of the small intestine.

The ileocolic artery branched off from the right semicircle of the superior mesenteric artery, and headed towards the distal ileum and cecum. In its course, the artery branched into anterior and posterior branches and gave off an artery for the appendix and the ascending colon.

The right colic artery branched off slightly above the ileocolic artery. It formed an anastomosis with the ascending branch of the ileocolic artery on the left, and with the right branch of the middle colic artery on the right. The middle colic artery branched off from the superior mesenteric artery trunk over the right colic artery. Closer to the intestinal wall, the vessel branched off into the right branch, which anastomosed with the branch of the right colic artery, and the left branch, which participated in the formation of the anastomosis along the colon with the branches of the left colic artery (from the inferior mesenteric artery) (Fig. 4).

A schematic representation of all anatomical variations is presented in Fig. 5.

Figure 4.

Superior mesenteric and its branches. 1: aorta; 2: splenic artery; 3: common trunk that branched into the left gastric artery, the upper right adrenal artery, and a branch to the diaphragm; 4: left gastric artery; 5: superior adrenal artery; 6: inferior phrenic artery; 7: hepato-mesenteric trunk; 8: common hepatic artery; 9: superior mesenteric artery; 10: right gastric artery; 11: gastroduodenal artery; 12: superior anterior pancreatoduodenal artery; 13: right gastroepiploic artery; 14: accessory right gastroepiploic artery; 15: pyloric artery; 16: inferior pancreatoduodenal artery; 17: greater pancreatic artery; 18: portal vein; 19: inferior vena cava; 20: left renal vein; 21: arteries to the small intestine; 22: iliac artery; 23: right colic artery; 24: middle colic artery; 25: the ascending colon; 26: superior mesenteric vein; 27: the descending colon; 28: the transverse part of the colon; 29: caecum; 30: loops of the ileum; 31: loops of the jejunum; 32: left kidney; 33: spleen; 34: the body of the pancreas; 35: head of the pancreas; 36: liver; 37: gallbladder; 38: common bile duct; 39: stomach (inverted, posterior surface); 40: greater omentum.

Figure 5.

Schematic representation of the arterial supply. A: aorta; St: stomach; Pl: pylorus; Sp: spleen; P: pancreas; D: duodenum; G: gallbladder; RLL: right liver lobe; LLL: left liver lobe; Ad: adrenal gland; RHD: right hemidiaphragm; E: esophagus; 1: splenic artery; 2: greater pancreatic artery; 3: arteries to the pancreatic tail; 4: left gastro-epiploic artery; 5: superior polar arteries to the spleen; 6: terminal branches of the splenic artery; 7: hepato-mesenteric trunk; 8: inferior pancreatic artery; 9: gastroduodenal artery; 10: left splenic artery; 11: right hepatic artery; 12: cystic artery; 13: left hepatic artery; 14: accessory left gastric artery; 15: terminal branches of the left hepatic artery; 16: common gastro-adreno-phrenic trunk; 17: accessory left gastric artery; 18: right phrenic artery; 19: superior adrenal artery and its branches; 20: anastomoses at the level of lower esophagus and gastric cardia; 21: anastomoses at the lesser gastric curvature; 22: anastomoses at the greater gastric curvature; 23: superior pancreatic artery; 24: inferior pancreatic artery; 25: two right gastro-epiploic arteries; 26: duodenal artery; 27: accessory right hepatic arteries; 28: pyloric artery.

The number of terminal branches of the celiac trunk is important to consider during surgery. Branching of the celiac trunk into three arteries occurs in 43.6%–90.9% of cases. At the same time, true trifurcation is distinguished, when all three vessels originate from one branch point (7.1%–6.9%) and false trifurcation, in which one of the arteries branches earlier. Bifurcation of the vessel is seen in 1.3% to 7.1% of cases. Additional branches are described in 5.2%–47.9% of cases. Most often, these branches are the inferior phrenic arteries (2.77%–41.4%), but they can also be lumbar arteries, arteries of the head or body of the pancreas, liver, stomach, and colon. Usually, there is only one accessory artery (5.2%–12.9%). However, there are cases when the celiac trunk branches into five branches (12.9%), six branches (1.4%), and seven branches (0.7%). Origin of the common hepatic, splenic, and left gastric artery independently from the aorta ranges from 0.38% to 2.6% of cases.^[6–8]

The celiac trunk has a central role in the blood supply to the liver, gallbladder, spleen, pancreas, and stomach. According to the latest classification proposed by Marco-Clement and coworkers based on radiological and anatomical studies, celiac trunk branching can be divided into four main types: complete (type I), incomplete (type II), no celiac trunk (type III), and celiacomesenteric trunk (type IV).^[9]

The rare types of celiac trunk branching is type III, in which all branches extend directly from the aorta or from its branches. Vandamme et al. reported this type of variation in 1.3% of 156 anatomical specimens.^[10] Iezzi et al., in their study on the basis of 524 CT angiograms, found this type in 0.6% of cases.^[11]

Variant anatomy of the common hepatic artery occurs in the world population on average in 10%–42% of cases. Single vessel variation is found in 22.89% of cases, and multiple arterial variations in 4.21% of cases.^[12] According to the latest data from a study by Faisal Hanif et al. based on 1000 CT angiograms, an accessory left hepatic artery occurs in 1.6%, while an accessory right hepatic artery is found in 0.7%.^[13] Presence of three accessory hepatic arteries that originate at the level of the pancreas is a rare case.

Accessory gastric arteries are relatively frequent in the population and most commonly originate from hepatic vessels (21.2%).^[14] The right gastric artery originates more often from the proper hepatic artery (53%), from the bifurcation point of the common hepatic artery (20%), from left hepatic artery (15%), and less commonly, from the gastroduodenal artery (8%) or common hepatic artery (4%). ^[15] The presence of accessory gastric arteries that originate from a common trunk together with adrenal and phrenic arteries from the aorta as in the current case is a rare entity.

The arterial supply of the pancreas is complex and there are various types of vascular supply of the gland.^[16] However, it is uncommon for an artery to travel through the gland without participating in its arterial supply as in the present case.

The inferior phrenic arteries originate from the aorta or celiac trunk and, in rare cases, from the renal arteries. There are reports of various other sites of origin, such as the left gastric, hepatic, superior mesenteric, spermatic, and adrenal arteries.^{[17, 18]} The current case is unusual since the right inferior phrenic artery originated from a common trunk together with the right superior adrenal artery and accessory left gastric artery. This is especially important as the right phrenic artery can participate in the vascular supply of the hepatocellular carcinoma, and can be cannulated for embolization.^[19]

Arterial anatomy of the abdominal cavity has a complicated embryological development due to organ migration and turn, which is accompanied by growth and degeneration of vascular structures. This is one of the reasons for supernumerary arteries in adults. Another important embryological cause is the unequal growth of walls of aorta that helps to fuse different arterial branches.^{[20, 21]} The decreased arterial degeneration combined with decreased arterial fusion results in the anatomical variations presented in the current case.

Arterial variations of the upper abdomen are relatively frequent, but usually are related to a single organ. Complex arterial variations can both pose a risk during surgical procedures and be beneficial during endovascular supply, as they provide additional access for embolization and chemotherapy.

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The authors have no funding to report.

The authors have declared that no competing interests exist.