The celiac plexus is the largest network of nerves in your abdomen, sometimes called the “solar plexus.” It sits deep in the belly, wrapped around the main artery that feeds your digestive organs, and acts as a central relay station for pain and other signals traveling between your gut and your brain. Most people encounter this term when dealing with severe abdominal pain, particularly from pancreatic cancer or pancreatitis, because doctors can target this nerve bundle to interrupt pain signals.
Where the Celiac Plexus Sits
The celiac plexus is located near the top of the abdomen, roughly behind the stomach and in front of the aorta (the body’s largest artery). It spans the area around the T12 and L1 vertebrae, which is approximately where your lowest ribs attach to your spine. The plexus wraps around two major blood vessels: the celiac artery, which supplies the stomach, liver, and spleen, and the superior mesenteric artery, which feeds the small intestine and part of the colon.
Rather than a single neat structure, the celiac plexus is a dense web of nerve fibers and clusters of nerve cell bodies called ganglia. The two largest are the right and left celiac ganglia, but individual anatomy varies quite a bit. The number of ganglia in the plexus ranges from 2 to 12, and they can be as small as 5 millimeters or as large as 45 millimeters. Two additional ganglia, the superior mesenteric ganglion and the inferior mesenteric ganglion, sit nearby and are interconnected with the main plexus.
Which Nerves Feed Into It
The celiac plexus receives input from two branches of the autonomic nervous system, the part of your nervous system that runs on autopilot without conscious control.
The sympathetic fibers, which generally speed up or slow down organ activity in response to stress, arrive through three sets of splanchnic nerves (the greater, lesser, and least). These originate from spinal cord levels T5 through T12, a stretch running from roughly the middle of your shoulder blades down to the bottom of your ribcage. The parasympathetic fibers, which tend to promote digestion and “rest and digest” functions, come primarily from the vagus nerve, the long cranial nerve that runs from the brainstem all the way into the abdomen.
What the Celiac Plexus Does
This nerve network controls much of what happens in your upper abdominal organs without you ever thinking about it. Its fibers reach the stomach, liver, gallbladder, spleen, kidneys, pancreas, small intestine, and the first portion of the large intestine. Through these connections, the plexus helps regulate how quickly food moves through your digestive tract, how much acid and digestive enzymes your stomach and pancreas release, and how blood flows through your abdominal organs.
Critically, the celiac plexus also carries pain signals. When an organ in your upper abdomen is inflamed, stretched, or invaded by a tumor, the pain travels through the celiac plexus on its way to your spinal cord and brain. This pain-carrying role is the reason the plexus became so important in medicine: blocking those signals at the source can relieve pain that medications alone cannot control.
Why It Matters in Pain Management
The celiac plexus is most commonly discussed in the context of a procedure called a celiac plexus block or neurolysis. Doctors target this nerve bundle primarily for two conditions: pancreatic cancer, where tumors press directly on or invade the plexus, and chronic pancreatitis, where ongoing inflammation of the pancreas produces severe upper abdominal or back pain.
In a celiac plexus block, a numbing agent is injected around the plexus to temporarily shut down pain transmission. In a neurolysis, alcohol or another substance is used to destroy the nerve fibers for longer-lasting relief. The initial success rate is high. About 94% of patients experience pain relief immediately after the procedure, and 70% to 90% of patients with pancreatic or other upper abdominal cancers get lasting benefit, with relief ranging from about 50 days up to the remainder of their lives. In one study of 61 patients with pancreatic cancer pain, 48% achieved complete pain relief after the procedure.
How the Procedure Is Performed
There are two main approaches. The percutaneous method involves inserting a needle through the skin of the back, guided by CT imaging or fluoroscopy, and advancing it toward the front of the aorta where the plexus sits. The endoscopic ultrasound-guided method uses a flexible scope passed through the mouth and stomach, with an ultrasound probe at its tip to guide needle placement from inside the body.
A randomized clinical trial comparing the two approaches in pancreatic cancer patients found them equally effective. At three months, about 23% of endoscopic patients and 37% of percutaneous patients had a successful pain response, a difference that was not statistically significant. Opioid use decreased similarly in both groups, and neither approach produced serious side effects. All adverse events observed were mild and temporary.
Common Side Effects of Celiac Plexus Procedures
Because the celiac plexus controls so many automatic functions in the abdomen, disrupting it produces predictable side effects. The two most common are diarrhea, occurring in 44% to 60% of patients, and a drop in blood pressure when standing up (postural hypotension), reported in 10% to 52% of patients. Both happen because blocking sympathetic nerve activity leaves the parasympathetic “rest and digest” system unopposed, which speeds up gut motility and relaxes blood vessels.
Rare but serious complications include back pain, collapsed lung (pneumothorax), and, in very uncommon cases, paralysis of the lower body. These risks depend on the approach used and the experience of the practitioner performing the procedure. Most side effects are self-limiting, and the hypotension that occasionally requires fluid support during the procedure resolves quickly with conservative treatment.
How Imaging Reveals the Plexus
The celiac plexus itself is too small and diffuse to see clearly on standard imaging, so doctors locate it using reliable anatomical landmarks. On a CT scan, the celiac trunk (the first forward-facing branch off the abdominal aorta, which splits into three arteries heading toward the stomach, liver, and spleen) serves as the primary marker. The plexus surrounds this artery’s origin point. Radiologists note the position of the aorta relative to the vertebral body at that level, which helps guide needle placement during procedures. The relationship between the celiac trunk, the aorta, and the spine varies from person to person, which is why imaging guidance is essential for any intervention targeting the plexus.