The celiac trunk is the first major branch of the abdominal aorta, emerging just below the diaphragm to supply blood to the stomach, liver, spleen, and parts of the pancreas and duodenum. In roughly nine out of ten people, it splits into three branches: the left gastric artery, the common hepatic artery, and the splenic artery. That classic three-way fork is recognizable to anyone who has studied anatomy, but the celiac trunk’s real-world behavior is more variable and clinically consequential than its textbook portrait suggests.
What the Celiac Trunk Does
Sitting at the level of the twelfth thoracic vertebra, the celiac trunk is a short, wide vessel, usually only a centimeter or two long before it divides. Its job is to feed the foregut-derived organs: the stomach, the upper part of the duodenum, the liver, the spleen, the gallbladder, and portions of the pancreas. During embryonic development, the celiac trunk forms from one of the vitelline arteries that originally supply the yolk sac. Those vitelline arteries reorganize into three vessels corresponding to the foregut, midgut, and hindgut: the celiac artery, the superior mesenteric artery, and the inferior mesenteric artery, respectively.1Edorium Journal of Anatomy and Embryology. Embryology, comparative anatomy, and congenital malformations of the gastrointestinal tract This developmental origin explains both the celiac trunk’s position and why so many of its variations involve shared branches with the superior mesenteric artery.
The Classic Three-Branch Pattern and Why It Is Not Universal
A systematic review pooling data from over 12,000 cases found that the celiac trunk showed the expected three-branch split (left gastric, common hepatic, and splenic arteries) in about 89% of people.2PubMed. Variations in the anatomy of the celiac trunk: A systematic review and clinical implications That means roughly one in ten people has some deviation. Some deviations are subtle, such as one of the three branches arising independently from the aorta instead of from the trunk. Others are dramatic. An analysis of over 1,500 CT angiograms identified seven distinct variant patterns in about 10% of patients. The three most common were the hepatomesenteric trunk (where the hepatic artery shares a common stem with the superior mesenteric artery, seen in roughly 4.5%), the celiomesenteric trunk (where the celiac and superior mesenteric arteries merge into a single vessel, about 3.4%), and the splenomesenteric trunk (about 1.2%).3PubMed. Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms
More extreme variants also exist. A case report in a one-year-old child described a celiac trunk that branched into five separate vessels, including both inferior diaphragmatic arteries and an accessory hepatic artery, with two distinct branching points along an S-shaped course.4PubMed Central. Unusual development of the celiac trunk and its clinical significance Cases like this are rare, but they illustrate that the celiac trunk is not a fixed architectural feature. It reflects whatever configuration the vitelline arteries settled into during the early weeks of fetal life.
Collateral Circulation and the Body’s Workarounds
One of the celiac trunk’s most clinically useful traits is its robust network of connections with the superior mesenteric artery. When the celiac trunk is narrowed or blocked, blood can detour through these collateral pathways to keep the liver, stomach, and spleen supplied. The most frequently encountered collateral vessels run through the pancreaticoduodenal arcades and the dorsal pancreatic artery, looping between the celiac and superior mesenteric territories.5PubMed. Collateral pathways in patients with celiac axis stenosis: angiographic-spiral CT correlation Another study found that the gastroduodenal artery was the most common collateral route in patients with celiac trunk narrowing.6PubMed. Collateral circulation develops in stenosis of the celiac trunk and superior mesenteric artery
These backup routes explain a somewhat counterintuitive phenomenon: many people walk around with significant celiac trunk narrowing and feel perfectly fine. The collateral vessels enlarge gradually in response to chronic stenosis, maintaining adequate blood flow to the organs. Problems arise when a surgeon inadvertently cuts across these collateral pathways during an unrelated operation, or when a second arterial territory (such as the superior mesenteric artery) also becomes compromised. With both supply routes reduced, the margin of safety disappears.
A related situation occurs after liver transplant when a large spleen draws so much blood through the splenic artery that the liver’s share of celiac trunk flow drops. This “splenic steal” syndrome can compromise the transplanted graft. One documented approach involves using a balloon catheter to temporarily occlude the splenic artery during celiac angiography. In one reported case, blocking the proximal splenic artery immediately improved contrast filling of the liver’s arteries, and subsequent embolization of the splenic artery maintained that improvement.7PubMed Central. Celiac trunk angiography with balloon occlusion of splenic artery for diagnosis and treatment of splenic steal syndrome
Median Arcuate Ligament Syndrome
The median arcuate ligament is a fibrous arch connecting the diaphragm’s two muscular crura. In most people, it crosses above the celiac trunk without incident. But in some individuals, it sits low enough to press down on the top of the celiac artery, pinching it against the aorta. When this compression causes symptoms, the condition is known as median arcuate ligament syndrome, or MALS. The clinical picture typically includes upper abdominal pain after eating, nausea, and unintended weight loss. Despite being recognized for decades, MALS remains a somewhat controversial diagnosis because the compression can be seen on imaging in people who have no symptoms, and the response to treatment is unpredictable.8PubMed. Median arcuate ligament syndrome: evaluation with CT angiography
Diagnosis relies heavily on imaging. CT angiography shows a characteristic focal narrowing at the top of the celiac artery, often described as a “hooked” appearance that distinguishes it from the more diffuse narrowing seen in atherosclerosis.9PubMed. Median arcuate ligament syndrome: evaluation with CT angiography Doppler ultrasound can serve as an initial screening tool: blood flow speeds in the celiac artery increase noticeably during expiration, when the diaphragm rises and pulls the ligament tighter against the vessel. One study confirmed that CT angiography correlates well with these ultrasound velocity findings and can replace conventional catheter-based angiography for confirming the diagnosis.10Journal of Vascular and Interventional Radiology. Evaluation of the Diagnostic Role of Doppler Ultrasonography and Computed Tomographic Angiography in Median Arcuate Ligament Syndrome
Treatment usually involves surgically dividing the ligament to free the artery. Increasingly, this is done laparoscopically or robotically. A study of pediatric patients undergoing robotic ligament release with removal of the celiac ganglion and nearby lymph nodes found that MALS is a neurovascular disorder involving both the artery and the nerve tissue around it, which may explain why some patients continue to have pain even after blood flow is restored.11PubMed. Pediatric Outcomes After Robotic Median Arcuate Ligament Release, Celiac Ganglionectomy, and Lymphadenectomy That nerve-compression component is an area of active investigation and helps explain why MALS does not always respond cleanly to a vascular fix alone.
Dissection, Aneurysm, and Thrombosis
The celiac trunk can develop its own standalone vascular emergencies, separate from atherosclerosis or external compression.
Spontaneous dissection of the celiac trunk happens when the inner lining of the artery tears and blood tracks into the vessel wall, creating a false channel. This is rare and overwhelmingly affects middle-aged men. A systematic review covering nearly three decades identified 169 patients with this condition; the average age was about 53, and abdominal pain was the hallmark symptom. Hypertension and smoking were the most frequently associated conditions, present in roughly 31% and 23% of patients respectively. Conservative management with blood pressure control and anticoagulation was the initial approach in about 79% of cases, and it works for most people.12PubMed. Systematic Literature Review on Evaluation and Management of Isolated Spontaneous Celiac Trunk Dissection The risk factors for failed conservative treatment include a longer stretch of dissection and involvement of the celiac trunk’s branch arteries.13PubMed. Clinical features and management strategy of symptomatic spontaneous isolated celiac artery dissection A smaller case series confirmed these trends and noted that two of ten patients later developed aneurysmal widening at the dissection site, requiring delayed endovascular repair with stenting.14PubMed. Evaluation and management of symptomatic isolated spontaneous celiac trunk dissection Long-term imaging follow-up is considered mandatory for this reason.
True aneurysms of the celiac artery are even rarer, with an estimated incidence of 0.005% to 0.01%. They arise from atherosclerosis (the most common predisposing factor, accounting for about 30% of cases), trauma, inflammation from pancreatitis or infection, and connective tissue disorders.15PubMed Central. Endovascular treatment of a large saccular aneurysm of the celiac artery: a case report and review of literature The reason they matter despite being uncommon is the rupture risk: between 15% and 20% of celiac artery aneurysms eventually rupture, with mortality from rupture reaching as high as 80%.16Journal of Vascular Surgery Cases, Innovations and Techniques. Surgical repair of a symptomatic celiac artery aneurysm with resection and end-to-end anastomosis Because of that dismal outlook once rupture occurs, repair is usually recommended when the aneurysm is found, regardless of size.
Thrombosis, an acute blood clot forming inside the celiac trunk, is the most immediately dangerous of the three. It can cause ischemic damage to the organs supplied by the celiac trunk’s end-arteries, particularly the spleen and parts of the liver, and may present as severe abdominal pain, organ necrosis, or even peritonitis from gallbladder or bile duct infarction.17PubMed. Acute celiac trunk thrombosis revealed by biliary peritonitis Underlying causes include conditions that increase clotting tendency: atherosclerosis, antiphospholipid syndrome, protein C or S deficiency, malignancies, and Behçet disease, among others.18PubMed Central. Celiac Trunk Thrombosis a Rare Cause of Acute Abdomen: Case Presentation Early diagnosis with angiography and prompt revascularization are critical.
Why Surgeons and Interventional Radiologists Care So Much About Variants
Celiac trunk anatomy is not academic trivia for surgeons. Knowing whether the hepatic artery originates from the celiac trunk in the usual location, or from the superior mesenteric artery, or directly from the aorta, changes the operative plan for multiple procedures.
In liver transplantation, a study comparing outcomes in recipients with variant versus normal hepatic artery anatomy found that those with variants had a hepatic artery complication rate of about 21%, compared to roughly 3% in those with classic anatomy, with the odds of complications roughly seven and a half times higher.19PubMed. Does variant hepatic artery anatomy in a liver transplant recipient increase the risk of hepatic artery complications after transplantation? Another transplant series, however, found that overall survival was generally not affected by arterial anomalies, with one exception: a specific variant where the right hepatic artery arises from the superior mesenteric artery and requires bench reconstruction before implantation was associated with longer cold storage time, greater blood loss, and shorter survival.20PubMed. Incidence of hepatic artery variations in liver transplantation: does it really influence short- and long-term results? The practical takeaway is that not all variants are equally troublesome. Some can be managed with minor adjustments; others demand complex vascular reconstruction that adds ischemia time and risk.
In pancreatic surgery, specifically the Whipple procedure (pancreaticoduodenectomy), the celiac trunk’s status matters for a different reason. This operation removes the head of the pancreas and part of the duodenum, which means cutting across some of the very collateral vessels that compensate for celiac stenosis. If the patient has significant celiac trunk narrowing from atherosclerosis or ligament compression and nobody notices before surgery, the liver and stomach can lose their blood supply when the collateral routes are severed. One study found that the rate of bile duct leakage after a Whipple procedure jumped from about 2.6% to 27% in patients with celiac artery stenosis.21PubMed Central. Pancreaticoduodenectomy in Patients With Coeliac or Superior Mesenteric Artery Stenosis: A Review of the Literature A large multicenter study confirmed that moderate-to-severe celiac stenosis independently doubled the risk of severe complications after this operation, including an elevenfold increase in gastric ischemia. Centers with standardized preoperative screening protocols identified and managed the stenosis more reliably.22Annals of Surgery. Impact of Celiac Axis Stenosis in Patients Undergoing Pancreatoduodenectomy and Total Pancreatectomy
In gastric cancer surgery, celiac artery variants affect how many lymph nodes can be safely removed during the operation. A study of over 400 gastric cancer patients found that about 26% had some form of celiac artery variation, and those patients had significantly fewer lymph nodes harvested on average (roughly 20 per case versus 24 in patients with standard anatomy).23PubMed Central. Relationship between celiac artery variation and number of lymph nodes dissection in gastric cancer surgery Thorough lymph node clearance is important for cancer staging and treatment planning, so a variant anatomy that limits the surgeon’s ability to dissect safely around the celiac trunk has downstream consequences for how accurately the cancer is staged.
Interventional Procedures and the Celiac Trunk as a Highway
For interventional radiologists, the celiac trunk serves as the main route into the liver’s arterial supply when performing procedures like chemoembolization for liver cancer (TACE). During TACE, a catheter is threaded into the celiac trunk and then advanced into the hepatic artery branches that feed the tumor, where a mixture of chemotherapy and embolizing agents is delivered directly. Vascular anomalies complicate this process but do not make it impossible. In one case involving a patient whose common hepatic artery was absent and replaced by two separate right hepatic arteries arising directly from the celiac trunk, plus a left hepatic artery coming off the left gastric artery, careful pre-procedural and real-time angiographic mapping allowed chemoembolization to be completed without complications.24Radiology Case Reports. Vascular anomalies of the celiac trunk and implications in treatment of HCC with TACE The lesson from these cases is consistent: variant anatomy is manageable when it is recognized before or during the procedure. The failures tend to happen when nobody checks.
Vasculitis and the Celiac Trunk
Systemic vasculitis, an autoimmune condition where the immune system attacks blood vessel walls, can involve the celiac trunk directly. The pattern of involvement depends on the type of vasculitis. In large-vessel diseases like Takayasu arteritis and giant cell arteritis, inflammation typically hits the proximal celiac trunk near its origin from the aorta, producing stenotic or occlusive lesions. Imaging shows stenosis or blockage in about a quarter of patients with Takayasu arteritis, though clinically significant gut symptoms develop in roughly 16%.25Annals of the Rheumatic Diseases. DIAGNOSIS OF GASTROINTESTINAL VASCULITIS In medium-vessel diseases like polyarteritis nodosa, the smaller muscular branches downstream of the celiac trunk are more commonly affected.
A case series illustrating this progression documented a patient with Takayasu arteritis whose celiac trunk stenosis worsened from 50% to between 75% and 90% over a period of years, alongside near-total occlusion of the superior mesenteric artery and significant narrowing of the renal arteries.26PubMed Central. Rare Systemic Vasculitides: Polyarteritis Nodosa and Takayasu Arteritis These cases are managed with a combination of immunosuppressive therapy to control the vessel inflammation and, when necessary, endovascular intervention to reopen critical stenoses. The celiac trunk is just one of many arterial beds affected, but its involvement can be the factor that tips a patient from subclinical disease into gut ischemia.
MALS in Children
Median arcuate ligament syndrome is not limited to adults, though published data on the pediatric population remain thin. Children and adolescents with MALS often present with chronic abdominal pain, nausea, and weight loss that may be dismissed as functional or psychological before the structural cause is identified. A pediatric-focused study examining outcomes of robotic-assisted ligament release with celiac ganglionectomy characterized MALS as a neurovascular disorder involving compression of both the artery and the surrounding nerve plexus.27PubMed. Pediatric Outcomes After Robotic Median Arcuate Ligament Release, Celiac Ganglionectomy, and Lymphadenectomy The dual-component nature of the syndrome, vascular and neural, may explain why outcomes in younger patients have been variable in the limited literature available. Children who undergo combined release of the ligament and removal of the compressed nerve tissue appear to fare better than those treated with ligament release alone, though this remains an area where larger studies are needed.
The diagnostic workup in pediatric patients mirrors the adult approach, starting with Doppler ultrasound and confirming with CT angiography. One practical difference is that children’s symptoms can evolve as they grow, because the positional relationship between the diaphragm, the ligament, and the celiac trunk changes with skeletal development. A child whose anatomy places the ligament borderline close to the artery may develop clinically significant compression during a growth spurt, only to have the relationship shift again later. This makes the diagnostic timeline messier than in adults, where the anatomy is fixed.