A calcified splenic artery aneurysm is a balloon-like bulge in the wall of the splenic artery (the blood vessel that supplies your spleen) that has developed calcium deposits along its outer wall. About 80% of splenic artery aneurysms show some degree of calcification, making it one of the most common features seen on imaging. These aneurysms are the third most common type of aneurysm in the abdomen, and most people who have one never know it until it shows up incidentally on a CT scan or X-ray done for something else entirely.
How Common Are Splenic Artery Aneurysms?
Prevalence estimates range widely, from about 0.1% in large autopsy studies to over 10% in autopsies of people older than 60 when the splenic artery was specifically examined. The wide range reflects how often these go undetected during life. With CT scans and other cross-sectional imaging now used routinely, the detection rate is climbing. Roughly 80% of asymptomatic splenic artery aneurysms are discovered incidentally during imaging ordered for an unrelated reason, such as abdominal pain evaluation or cancer screening.
Only about 3 to 4% of people with these aneurysms ever develop symptoms. In one study tracking 137 patients over time, 65% showed no change in aneurysm size on follow-up scans, while 35% showed some expansion.
Why the Artery Wall Calcifies
Calcification happens when calcium deposits gradually build up in the artery wall, typically as part of atherosclerosis, the same process that hardens arteries elsewhere in the body. Over time, fatty deposits in the vessel wall attract calcium, forming a rigid shell. In splenic artery aneurysms specifically, this calcification tends to appear along the outer rim of the bulge, creating what radiologists describe as “peripheral” or “eggshell” calcification on imaging.
The splenic artery is particularly prone to this because of its winding, tortuous shape and the hemodynamic forces it experiences. People with portal hypertension (high pressure in the liver’s blood supply, often from cirrhosis) face additional risk. In portal hypertension, reduced blood flow through the liver forces more blood through the splenic artery, creating a “hyperkinetic” circulation pattern. This increased flow and pressure can weaken the vessel wall over time, leading to aneurysm formation. Other contributing factors include an enlarged spleen and hormonal influences, which is why these aneurysms are more common in women, particularly those who have been pregnant multiple times.
What Calcification Means for Rupture Risk
Here’s what most people reading an imaging report want to know: calcification appears to be protective. A study following 59 patients with splenic artery aneurysms over 17 years found that eggshell-pattern calcification was an independent factor associated with slower aneurysm growth. When the rigid calcium shell surrounds the aneurysm wall, it essentially acts as a natural reinforcement, restricting the bulge from expanding further.
This protective effect was especially notable in patients who had other risk factors for growth, such as portal hypertension or an aneurysm already larger than 20 mm. In those higher-risk patients, the presence of eggshell calcification significantly blunted the rate of expansion compared to similar patients without calcification. None of the patients in the study experienced rupture during the follow-up period.
That said, calcification alone doesn’t eliminate risk. An aneurysm larger than 2 cm, one that’s growing rapidly (more than 0.5 cm per year), or one in a person with portal hypertension still warrants close monitoring regardless of calcification status.
How It Looks on Imaging
Most calcified splenic artery aneurysms are first spotted on CT scans, where they appear as round or oval structures with a bright white calcium rim along the wall. Some show up even on plain abdominal X-rays as a ring of calcium in the upper left abdomen. On contrast-enhanced CT, the aneurysm fills with contrast dye in its center (confirming blood is still flowing through it), while the calcified wall stands out clearly at the edges. Some aneurysms also contain blood clot (thrombus) along the inner wall, which appears as a darker layer between the flowing blood and the calcified shell.
In one imaging study of 45 patients, about 24% had visible peripheral wall calcifications on CT. The aneurysms found incidentally in otherwise healthy patients tended to be smaller than 20 mm, solitary, and more likely to show calcification compared to those caused by conditions like pancreatitis or liver disease.
When Treatment Is Recommended
Most small, calcified, asymptomatic splenic artery aneurysms are managed with periodic imaging to monitor for growth. Current guidelines recommend treatment in specific situations: when the aneurysm exceeds 2 cm in diameter, when it’s growing more than 0.5 cm per year, when it causes symptoms (typically left-sided abdominal or back pain), or when it has ruptured.
Pregnancy represents a special concern. Women of childbearing age with a known splenic artery aneurysm are generally offered treatment before pregnancy because rupture during pregnancy carries an extremely high mortality rate: roughly 75% maternal mortality and 95% fetal mortality. For comparison, rupture in the general population carries about a 25% mortality rate. The increased blood volume and hormonal changes of pregnancy are thought to stress the already weakened artery wall.
Treatment Options
When intervention is needed, there are two main approaches: endovascular repair (a minimally invasive procedure done through a catheter threaded into the artery) and open surgery.
In an elective, non-emergency setting, endovascular repair is often preferred for stable aneurysms larger than 2 cm. The procedure involves threading a catheter through a blood vessel, usually from the groin, and blocking off the aneurysm using coils or other devices. Recovery is typically faster than open surgery, and hospital stays are shorter.
A systematic review of 350 patients treated for ruptured splenic artery aneurysms found that overall mortality was about 10.6%, with no statistically significant difference between open surgery (12.9%) and endovascular repair (7.8%). However, there’s an important nuance: endovascular repair carried a substantially higher rate of reintervention. About 22% of patients treated with catheter-based techniques needed a second procedure, often conversion to open surgery, compared to only 1.6% of those who had open repair initially. Complication rates were similar between the two approaches at around 4 to 7%.
For emergencies, particularly rupture during pregnancy or in patients with unstable blood pressure, open surgery remains the more reliable choice. It typically involves removing the aneurysm and sometimes the spleen along with it. Long-term data on quality of life and recovery timelines after either approach are limited, as most published studies focus on survival and immediate complications.
Living With a Calcified Splenic Artery Aneurysm
If your imaging report mentions a small, calcified splenic artery aneurysm, the most likely path forward is surveillance. This usually means repeat CT scans at intervals your doctor determines based on the aneurysm’s size and your overall health profile. The calcification is actually a reassuring feature, suggesting the aneurysm wall has stabilized to some degree. Most people with these findings live their entire lives without the aneurysm ever causing a problem.
The key numbers to track are the aneurysm’s diameter and its rate of change over time. An aneurysm sitting at 1.5 cm with no growth over a year or two of monitoring is a very different situation from one at 2.5 cm that has expanded since the last scan. Understanding this distinction helps you have more productive conversations about whether continued observation or intervention makes sense for your specific case.