Chronic Thrombosis of Celiac Axis with SMA Stenosis: IMA to the Rescue

We present the case of a 60-year-old male who arrived at the emergency department with acute abdominal pain and abdominal distension of 1-day duration. He had no known comorbidities and was not on any regular medications, including antiplatelets, anticoagulants, or nonsteroidal anti-inflammatory drugs (NSAIDs). Clinical examination revealed features suggestive of peritonitis. An urgent contrast-enhanced computed tomography (CT) of the abdomen along with CT angiography was performed, which revealed a gastric antral perforation, pneumoperitoneum, and free peritoneal fluid.

Incidentally, CT angiography also revealed complete thrombosis at the origin of the celiac trunk, attributed to chronic atherosclerotic plaque. Notably, all three major branches of the celiac axis—the left gastric artery (LGA), common hepatic artery (CHA), and splenic artery—were occluded. Despite this extensive thrombosis, prominent collateral circulation was observed. A well-developed pancreaticoduodenal arterial arcade near the pancreatic head was seen supplying the CHA and LGA. Numerous tortuous arterial collaterals had formed, effectively replacing the function of the splenic artery.

Further evaluation revealed the right gastric artery arising normally from the CHA, and the right gastroepiploic artery originating from the gastroduodenal artery. The left gastroepiploic artery, however, was not visualized. Instead, multiple small arterial branches, presumably collaterals, were seen supplying the gastric fundus. Additionally, a significant stenosis at the origin of the superior mesenteric artery (SMA) was identified. Compensatory vascular remodeling was evident in the form of a prominent arc of Riolan connecting the SMA and the inferior mesenteric artery (IMA) ([Fig. 1]).

Fig. 1 Coronal maximum intensity projection (A) and volume rendered (B) computed tomography (CT) image show common hepatic artery (CHA) (white thin arrow) and left gastric artery (LGA) (curved arrow) arising from the peripancreatic arcade. Enlarged arc of Riolan is seen between superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) (dashed arrow). Multiple collaterals are seen replacing the splenic artery (thick white arrow) arising from the peripancreatic arcade and arc of Riolan. Oblique coronal volume rendered CT image (C) shows ostial stenosis in SMA (black arrow) and filling defect at the site of origin of celiac trunk due to atherosclerotic plaque. IMA, inferior mesenteric artery.

Celiac artery (CA) thrombosis is an incidental finding seen in a notable proportion of patients undergoing abdominal CT imaging, with reported incidence ranging from 12.5 to 49%.[1] The CA plays a crucial role in perfusing the upper abdominal viscera, including the stomach, liver, spleen, pancreas, and proximal duodenum. In cases where the celiac axis is occluded, the body often compensates via collateral pathways, predominantly through the pancreaticoduodenal arcades and anastomoses between the left and right gastric arteries and the gastroepiploic arteries—pathways that represent inter- and intraceliac collateral networks.[2]

The present case is remarkable due to the complete thrombosis of the entire celiac axis along with all its branches, which is rarely documented. The collateral circulation supplying the upper abdominal organs had to be entirely rerouted through the pancreaticoduodenal arcades—branches of the SMA. However, with a high-grade stenosis at the SMA origin, this compensatory mechanism was further challenged. The presence of a markedly developed arc of Riolan—a collateral connection between the IMA and SMA—underscored the extent to which the body had adapted to preserve visceral perfusion. This unique vascular remodeling enabled maintenance of blood supply to both the bowel and the solid upper abdominal organs in the face of critical arterial compromise.

Although CA occlusion is sometimes asymptomatic due to such collateralization, in this patient, the coexistence of SMA stenosis critically limited the perfusion reserve. This compounded visceral ischemia, most notably affecting the gastric antrum, which in turn predisposed the patient to ischemic gastric perforation. In the absence of other identifiable risk factors—such as peptic ulcer disease, Helicobacter pylori infection, NSAID use, or malignancy—chronic gastric ischemia due to arterial insufficiency was determined to be the most plausible cause. The patient underwent emergency surgical repair of the gastric perforation and was started on oral dual-antiplatelet therapy to prevent future episodes of visceral ischemia. He recovered well postoperatively with no further ischemic complications and was discharged in stable condition after 5 days.

This case highlights several key learning points. First, complete thrombosis of the celiac trunk and its branches is rare and can be easily overlooked if not systematically evaluated, especially in the absence of overt symptoms. Second, the development of dual-level compensatory collateral pathways—from the SMA to celiac territory and further from the IMA to SMA—is a fascinating example of vascular adaptation. Third, it reinforces the role of CT angiography with advanced reconstruction techniques such as maximum intensity projection and volume-rendered reconstruction in clearly delineating complex vascular anatomy and its pathological alterations.[3]

Understanding these collateral routes is not just of academic interest but has direct clinical implications. In cases of unexplained abdominal pain or visceral ischemia, especially in older patients with known atherosclerotic disease, a thorough evaluation of the mesenteric and celiac vasculature is warranted. Moreover, recognition of collateral pathways becomes crucial during surgical interventions or endovascular procedures, where inadvertent ligation or compromise of such vessels can lead to catastrophic outcomes.

In conclusion, this case documents a rare and severe form of chronic splanchnic arterial insufficiency with adaptive collateralization via the IMA. It highlights the critical role of radiologic imaging in identifying both the underlying etiology and the compensatory mechanisms in patients presenting with acute abdominal emergencies. Early recognition of such vascular anomalies can significantly impact patient outcomes by guiding appropriate surgical and interventional management strategies.

Conflict of Interest

None declared.

Acknowledgment

None.

Ethics Statements

Informed consent was obtained from the patients.

Data Sharing Statement

No data were generated or analyzed during the study.

• References

• 1 Park HM, Lee SD, Lee EC. et al. Celiac axis stenosis as a rare but critical condition treated with pancreatoduodenectomy: report of 2 cases. Ann Surg Treat Res 2016; 91 (03) 149-153
• 2 White RD, Weir-McCall JR, Sullivan CM. et al. The celiac axis revisited: anatomic variants, pathologic features, and implications for modern endovascular management. Radiographics 2015; 35 (03) 879-898
• 3 Ozbülbül NI. CT angiography of the celiac trunk: anatomy, variants and pathologic findings. Diagn Interv Radiol 2011; 17 (02) 150-157

Publication History

Article published online:
28 May 2025