The abdominal aorta predominantly provides blood supply to the upper abdominal cavity and its contents. Among many of its branches, the first major branch of the abdominal aorta is the celiac trunk also known as the celiac artery. It is a short vessel that arises from the aorta, passing below the median arcuate ligament, just as the aorta enters the abdomen at the thoracic level of the T12 vertebra. The celiac trunk measures about 1.5cm to 2cm in length.
The celiac trunk classically divides further into three branches:
Besides the classic presentation of celiac trunk trifurcating into its branches, there have been numerous reported cases of variations in the celiac trunk's branching. These cases include, but are not limited to, celiac trunk bifurcation into the hepatic artery, and splenic artery, the absence of the trunk itself as it may arise commonly with the superior mesenteric artery (celiacomesenteric trunk).
Also, the celiac trunk may also give rise to inferior phrenic arteries. These arteries may spring either from the aorta or the celiac trunk.
The celiac trunk supplies blood to the foregut, namely:
The arterial system undergoes various modifications within an embryo during its growth. Intraembryonically, the arterial system consists of aortic arches, and the central and dorsal aortas, that are all continuous with each other. Arising from the dorsal aorta are paired ventral segmental arteries some of which fuse to form the median vessels. These vessels, then further, give rise to the three main arterial systems: celiac trunk, superior mesenteric artery, and inferior mesenteric artery.
Most patients present with asymptomatic vascular anomalies of the celiac trunk. However, vital knowledge of the celiac trunk, its branches, and vascular variations are important with any involvement of the upper abdomen with surgical procedures such as liver transplant or diagnostic procedures like angiography for gastrointestinal bleeding or celiac axis compression syndrome. In addition, the vascular anatomy of the celiac trunk also plays a crucial role in arterial anastomoses during surgery. Moreover, recognition of variations in abdominal arteries that supply the liver, pancreas, gallbladder, and spleen can also help in reducing the blood loss during surgical procedures involving these areas.
Celiac Artery Compression Syndrome
Also, commonly known with several terms such as celiac axis syndrome, median arcuate ligament syndrome (MALS), Marable syndrome and Dunbar syndrome.
This syndrome is characterized by angina localized to upper abdomen due to the compression of the celiac artery by diaphragmatic crura.
The median arcuate ligament is a fibrous arch that connects the right and left diaphragmatic crura around the aorta, at the base of the diaphragm. If this ligament is low lying due to its highly variable locations, it can compress or distort the celiac trunk in a downward angle resulting in an unpleasant or an excruciating epigastric pain. The pain is often relieved in standing position and is exacerbated when in the supine position. This syndrome is commonly seen in 20 to 40-year-old patient population. In certain individuals, this may also result in mesenteric ischemia. Most common complain apart from the epigastric pain is also postprandial pain which results in weight loss.
CT angiography would reveal a focal stenosis with a characteristic hook-shaped appearance due to the distort shape of the celiac trunk on its superior surface. Since the celiac can have a similar appearance upon expiration in a healthy patient, it is important to make the diagnosis of celiac artery compression syndrome by correlating the imaging findings with patient history.
Treatment of this syndrome is usually reserved for patients who are symptomatic performed via laparoscopic surgical decompression by dividing the median arcuate ligament.
Although rarely found in clinical cases, celiac artery aneurysm can occur as a form of splanchnic artery aneurysm. A celiac aneurysm is typically asymptomatic until it ruptures. Since the rupture of the celiac trunk aneurysm is associated with high morbidity and mortality rates, early recognition of this vascular anomaly becomes crucial. It is often found incidentally on diagnostic imaging studies such as arteriography or post rupture in autopsies.
Celiac Trunk Dissection
Most commonly, the cause of a celiac trunk dissection is iatrogenic. However, often comorbidities such as atherosclerosis, hypertension, pre-existing vascular diseases such as fibromuscular dysplasia, and even pregnancy can be predisposing factors to arterial dissection. Alternative factors can also include trauma due to a sudden increase in intra-abdominal pressure, or they can be mechanical. Celiac trunk dissections are frequently asymptomatic but may present with abdominal pain if there is involvement of bowel ischemia secondary to rupture of other abdominal arteries such as splenic, renal or superior mesenteric arteries.
Typically, the presence of an isolated dissection is a very uncommon sighting in clinical practice and is found incidentally post aortic dissection finding.
The optimal means of diagnosing celiac trunk dissection is contrasting CT or CT angiography. However, other imaging studies such as MR angiography or sonography can also be considered. On diagnostic imaging, the most common finding for the dissection is an intimal flap and/or a presence of mural thrombus in the lumen of the celiac trunk.
Surgery is usually needed to manage celiac trunk dissection to prevent further acute complications such as rupture, intestinal ischemia or chronic complications such as arterial stenosis. However, if the dissection can be diagnosed as limited, the aim shifts toward preventing thromboembolic events. In such cases, treatment is conservative with the use of anticoagulation and anti-hypertensives to control the blood pressure. An additional option can also include evaluating the collateral supply and managing the endovascular itself.