Left Gastric Artery Anatomy, Surgical Variations, and Risks

The left gastric artery is the smallest of three branches that typically arise from the celiac trunk, the first major vessel off the abdominal aorta below the diaphragm. It runs upward and to the left, supplying blood to the lower esophagus and the upper portion of the stomach along the lesser curvature. Despite its modest size, this artery punches well above its weight in clinical medicine: it is a critical landmark in gastric cancer surgery, a target in experimental obesity treatments, and the origin of variant blood vessels that can make or break liver transplants and pancreatic operations.

Where It Comes From and Where It Goes

In the textbook arrangement, the celiac trunk divides into three branches: the left gastric artery, the common hepatic artery, and the splenic artery. A cadaveric study of 140 dissections found this classic trifurcation pattern in about 44% of cases, though the researchers noted that a true tripod where all three branches leave the trunk at a single point occurred in only about 7% of specimens; the rest had a “false tripod” where one branch departed slightly before or after the others.¹ In practical terms, the left gastric artery originates from somewhere near the celiac trunk in the vast majority of people, but the exact geometry varies more than anatomy textbooks suggest.

Once it branches off, the left gastric artery heads toward the gastroesophageal junction, the spot where the esophagus meets the stomach. It gives off ascending branches that feed the lower esophagus and then turns downward along the lesser curvature of the stomach. A CT-based study in a Vietnamese population confirmed that the most common branching pattern involves the artery supplying the esophagus, the gastroesophageal junction, and the lesser curvature in a predictable sequence.² Along the lesser curvature it eventually meets branches of the right gastric artery coming from the other direction, creating an arterial arcade that keeps the upper stomach well perfused.

Variations That Surgeons Need to Know About

The left gastric artery’s single most important quirk is that it sometimes gives rise to an artery that feeds the left lobe of the liver. In the standard arrangement, all arterial blood to the liver comes through the common hepatic artery. But in a significant minority of people, the left hepatic artery (or a branch doing its job) takes off from the left gastric artery instead. A meta-analysis pooling data from multiple studies found that this aberrant left hepatic artery shows up in roughly one in seven people, with an overall prevalence of about 13.5%.³ A large single-center imaging study of over 5,600 patients put the prevalence of aberrant left hepatic arteries at about 16%.⁴

The distinction between “replaced” and “accessory” matters here. A replaced left hepatic artery is the sole blood supply to the left liver lobe; the normal left hepatic branch is absent. An accessory left hepatic artery is a bonus vessel that supplements the usual one. Across the pooled studies, replaced variants were somewhat more common (about 8%) than accessory ones (about 6%).⁵ Whether a surgeon can safely cut through the left gastric artery depends heavily on which type is present, since severing a replaced artery means the left liver lobe loses its only blood supply.

Rarer still, the left gastric artery can originate directly from the aorta rather than from the celiac trunk. A cadaveric case report documented exactly this arrangement, with the left gastric artery forming its own separate trunk lateral to the celiac trunk.⁶ In extremely rare cases, the celiac trunk is absent altogether, and all three of its usual branches arise independently from the aorta. Radiologic and cadaveric series have recorded this complete absence anywhere from 0.1% to 2.6% of the time. A classification system developed by Morita accounts for this by designating it as a distinct type alongside other celiac trunk variants like hepatosplenic or gastrosplenic trunks.

Why This Matters During Gastric Cancer Surgery

Gastrectomy for stomach cancer routinely involves dividing the left gastric artery at its root. The vessel is tied off to remove the lymph nodes clustered around it, because the stomach’s lymphatic drainage follows its arterial supply. The Japanese Gastric Cancer Association classifies the regional lymph nodes around the stomach into 33 stations, and the nodes along the left gastric artery (station 7) are among the most likely to harbor metastases from tumors on the upper stomach or lesser curvature.⁷ A thorough lymph node dissection in that area requires taking the artery with it.

The complication risk enters when the left gastric artery happens to carry a replaced left hepatic artery. A study of patients undergoing laparoscopic distal gastrectomy for gastric cancer compared outcomes in those whose replaced left hepatic artery was divided versus preserved during the operation. The group where the artery was divided had a hepatic infarction rate of nearly 17%, compared to zero in the group where the variant vessel was preserved. Dividing it was also an independent risk factor for elevated liver enzymes after surgery.⁸ Surgeons now increasingly plan around these variants, modifying the extent of their lymph node dissection to avoid cutting off the liver’s blood supply.

This is where modern imaging comes in. Three-dimensional CT angiography performed before surgery can identify the left gastric artery and its branches with high reliability. One study of 36 patients reported that 3D CTA correctly identified the left gastric artery and any replaced hepatic branches in every single case.⁹ More advanced 256-slice CT scanners have proven especially effective at mapping smaller arterial variants before gastric cancer operations, using reconstruction techniques that give surgeons a three-dimensional road map of the blood vessels they will encounter.¹⁰

The Left Gastric Artery in Liver Transplantation

The same variant anatomy that complicates gastric surgery creates a dilemma in liver transplants. When a donor liver has an aberrant left hepatic artery coming off the left gastric artery, the transplant team has to decide: preserve it or tie it off? Keeping it means more complex arterial reconstruction during transplant, which can increase the risk of hepatic artery thrombosis, a dreaded complication where the newly connected artery clots. Tying it off risks leaving part of the graft underperfused, which can lead to bile duct damage and graft dysfunction.

A prospective study of 395 liver transplant grafts found that about 16% had an aberrant left hepatic artery. The team used a series of five intraoperative tests to determine whether each variant was accessory or replaced, then followed a decision algorithm: ligate it if accessory, preserve it if replaced. They ligated the variant vessel in just over half of cases and preserved it in the rest. After an average follow-up of about four years, the rates of artery thrombosis, graft dysfunction, biliary complications, and overall survival were similar in both groups.¹¹ The takeaway is that once you can confidently distinguish accessory from replaced, ligation is safe for the accessory type, but the identification step is non-negotiable.

Pancreatic Surgery and Arterial Reconstruction

A particularly demanding scenario arises during distal pancreatectomy with celiac axis resection, an operation sometimes performed for pancreatic cancer that invades the celiac trunk. The procedure involves removing the celiac axis itself, which normally cuts off blood flow to everything downstream. When a patient has a replaced left hepatic artery originating from the left gastric artery, the stakes climb further: not only does the liver lose its usual arterial supply from the celiac trunk, it also relies on a variant vessel that branches from one of the trunk’s doomed limbs. A case report described a novel technique for reconstructing the left gastric artery specifically to preserve a replaced left hepatic artery during this operation.¹² Cases like these underscore how a single small artery variant can reshape an entire surgical plan.

Esophageal Cancer Operations

In esophagectomy, the left gastric artery is deliberately divided to mobilize the stomach so it can be pulled up into the chest as a replacement conduit for the removed esophagus. The stomach survives this because its blood supply is redundant: even after the left gastric artery is sacrificed, the right gastric, right gastroepiploic, and short gastric arteries continue to feed it. Some centers perform preoperative laparoscopic ligation of the left gastric vessels during the staging laparoscopy that patients undergo anyway. A series of nine patients demonstrated that this approach was safe and could be combined with staging, potentially streamlining the eventual esophagectomy.¹³

Collateral Flow and the Stomach’s Resilience

The stomach is one of the best-perfused organs in the abdomen, with multiple overlapping arterial supplies. This redundancy means that blocking the left gastric artery alone rarely causes tissue death. A classic study of gastric physiology after selective embolization found that blocking the left gastric artery with gelatin sponge particles still allowed significant collateral blood flow to reach the gastric mucosa.¹⁴ By contrast, vasopressin infusion, which constricts the tiny arterioles and capillaries throughout the stomach wall, was far more effective at reducing mucosal blood flow. The practical lesson: you can occlude the left gastric artery trunk and the stomach compensates through alternative routes, but drugs that act on the microcirculation bypass those collaterals entirely.

Bariatric Embolization for Weight Loss

One of the more surprising chapters in the left gastric artery’s story is its potential role in obesity treatment. The idea is straightforward: the gastric fundus, the dome-shaped top of the stomach, is where most of the body’s ghrelin is produced. Ghrelin is the hormone that tells your brain you are hungry. The left gastric artery is a major supplier of blood to the fundus. Deliberately embolizing it, threading a catheter through the groin and injecting tiny particles that block the artery, reduces blood flow to the fundus and suppresses ghrelin production.¹⁵

The concept was first tested in animals. A canine study showed that left gastric artery embolization suppressed circulating ghrelin levels and led to reductions in subcutaneous fat and body weight, although the researchers also noted that compensatory ghrelin production from the remaining fundal tissue may limit the long-term effect.¹⁶

Human trials followed. The BEAT Obesity trial enrolled severely obese adults and embolized the left gastric artery (sometimes along with the gastroepiploic artery). Early safety data on the first five patients showed the procedure was technically successful in every case, with excess weight loss averaging about 9% at three months and measurable drops in ghrelin levels.¹⁷ At the one-year mark in a larger cohort, mean excess weight loss was about 11.5%, quality-of-life scores improved, and appetite remained below pre-procedure levels throughout the year, though the strongest appetite suppression occurred in the first four weeks and then partially waned.¹⁸

These numbers are modest compared to surgical options like gastric bypass, but the appeal of bariatric embolization lies in its minimally invasive nature: it requires only a small puncture in the groin, no general anesthesia, and no permanent anatomical changes to the stomach. The procedure remains investigational. Larger randomized trials are needed to see whether the weight loss holds beyond one year and whether the ghrelin-compensating effect limits durability. Still, it represents a genuinely novel use of a vessel that most people have never heard of.

Pseudoaneurysms and Vascular Emergencies

Though rare, the left gastric artery can develop pseudoaneurysms, ballooning weak spots in the vessel wall that are contained only by the outermost layer or surrounding tissue rather than by the full arterial wall. Unlike true aneurysms where all layers of the artery expand together, a pseudoaneurysm is essentially a rupture held in check by a thin barrier, making it prone to catastrophic hemorrhage if it breaks open.

Pancreatitis is one of the more common triggers. A case report described a 14-year-old with chronic calcifying pancreatitis who developed a left gastric artery pseudoaneurysm presenting as a palpable abdominal mass and severe pain. CT imaging revealed the pseudoaneurysm in the lesser sac, and interventional radiologists treated it by threading tiny coils through a catheter to block off the artery, avoiding emergency open surgery altogether.¹⁹ Pseudoaneurysms can also form after gastric surgery. A case series found that the majority of hematemesis episodes following sleeve gastrectomy were caused by pseudoaneurysms, with the left gastric artery implicated in two of those cases. Endovascular embolization, rather than open repair, is now the preferred treatment for these emergencies because of fewer complications and better outcomes.²⁰

Dieulafoy Lesions and the Posterior Stomach

Another vascular emergency linked to the left gastric artery’s territory is the Dieulafoy lesion. This is a tortuous, abnormally large submucosal artery, most commonly found along the posterior wall of the upper stomach, that gradually erodes through the overlying mucosa. When it finally breaches the surface, the result is sudden, severe gastrointestinal bleeding that can be life-threatening. The lesion is notoriously hard to find on endoscopy because the mucosal defect is tiny and there is no surrounding ulcer to signal its location. The artery involved is typically a branch that traces back to the left gastric artery’s distribution along the lesser curvature and proximal stomach. Treatment usually involves endoscopic clipping or cauterization, but in refractory cases angiographic embolization of the feeding branch may be required.

What makes Dieulafoy lesions tricky is their intermittent nature. The bleeding can stop and restart unpredictably, so a patient may arrive at the hospital with a massive bleed, undergo endoscopy that finds nothing, and then bleed again hours later. Awareness that the posterior stomach, squarely within the left gastric artery’s territory, is the most common site helps endoscopists know where to look hardest during repeat examinations.