MALS surgery is a procedure that releases the median arcuate ligament, a band of fibrous tissue near the diaphragm that is compressing the celiac artery and surrounding nerves. The surgery cuts through the ligament fibers to restore blood flow and relieve the chronic abdominal pain, nausea, and weight loss that define median arcuate ligament syndrome. Most patients stay in the hospital for 2 to 3 days afterward.
What the Surgery Actually Does
The core of the operation is straightforward in concept: the surgeon divides the tight band of tissue (the median arcuate ligament) that is pressing down on the celiac artery where it branches off the aorta. This compression restricts blood flow to the stomach, liver, and spleen, and it irritates a bundle of nerves called the celiac plexus. During the procedure, the surgeon separates the ligament fibers and clears away surrounding tissue from the beginning of the celiac trunk. In some cases, the celiac ganglia (nerve tissue clustered around the artery) are also removed to address the nerve-related component of the pain.
For a smaller number of patients, releasing the ligament alone isn’t enough to restore adequate blood flow. If the artery has been compressed for a long time or has developed scarring, the surgeon may also need to dilate the artery, perform a bypass, or reconstruct the vessel. These vascular procedures can be done during the same operation or planned as a follow-up.
Laparoscopic, Robotic, and Open Approaches
There are three main ways surgeons perform the ligament release: traditional open surgery (laparotomy), standard laparoscopic surgery, and robotic-assisted laparoscopic surgery. The laparoscopic and robotic approaches use small incisions and a camera, while open surgery requires a larger abdominal incision.
Compared to open surgery, minimally invasive approaches reduce surgical trauma and shorten hospital stays. A nationwide analysis of MALS procedures performed between 2010 and 2020 found that the open approach carried a significantly higher rate of major complications: 4.0% versus just 0.5% for minimally invasive cases. Open surgery also had higher rates of pulmonary complications (2.6% vs. 0%) and reoperations (2.6% vs. 0%). Most surgeons now favor minimally invasive techniques when the anatomy allows it.
Robotic-assisted surgery uses the da Vinci Surgical System, which gives the surgeon a wider visual field and finer instrument control. A retrospective study comparing the two minimally invasive approaches found that robotic cases took longer (134 minutes on average versus 86 minutes for standard laparoscopic), but both achieved equivalent improvements in blood flow through the celiac artery. Robotic patients reported significantly better relief of pain after eating and chronic nausea. Hospital stays averaged one day for both groups. Both approaches are considered safe and effective at experienced centers.
How Well It Works
MALS surgery helps the majority of patients, but complete resolution of symptoms isn’t guaranteed. A single-institution review found that within one year of surgery, 40% of patients had complete symptom relief, 38% had partial relief, and 21% saw no improvement. That means roughly 4 out of 5 patients experienced some meaningful benefit, though nearly half of those still had lingering symptoms.
One challenge is that doctors can’t reliably predict beforehand who will respond best. A study tracking patients for one year after laparoscopic release found that no conventional imaging measurement, including artery velocity, the angle of compression, or the shape and size of the narrowing on CT scans, could predict whether a patient would have a good clinical outcome. The structural findings simply don’t map neatly onto symptom relief, which is part of why MALS can be frustrating for both patients and surgeons.
Some centers use a celiac plexus block (an injection that temporarily numbs the nerve bundle near the artery) before surgery to help gauge whether a patient’s pain is driven by nerve irritation. If the block provides temporary relief, it suggests the surgery is more likely to help. This isn’t universally used, but it can be a useful tool when the diagnosis is uncertain.
Risks and Complications
The overall complication rate for MALS release is about 12%, with most of those being minor. Major complications, defined as events serious enough to potentially require a return to the operating room or intensive-level care, occurred in 3.1% of patients in the nationwide analysis. Choosing a minimally invasive approach dramatically lowers that risk.
Pulmonary complications like pneumonia or blood clots in the lungs were the most notable category, occurring in 2.6% of open cases and essentially zero percent of laparoscopic cases. Conversion from a minimally invasive approach to open surgery is uncommon. In the robotic versus laparoscopic comparison study, no patients in either group required conversion to an open procedure.
Recovery and What to Expect
A typical hospital stay after MALS release is 2 to 3 days, though patients who have minimally invasive surgery sometimes go home after just one day. Pain at the incision sites is manageable and improves over the first week or two. Because the surgery involves the area around the diaphragm, some patients notice discomfort with deep breathing initially.
Symptom improvement can happen quickly for some patients and take months for others. The nerve irritation component of MALS can be slower to resolve than the vascular component, so nausea or pain may linger even after blood flow has been restored. Follow-up typically includes ultrasound imaging to confirm that the celiac artery is flowing freely, though as noted above, those measurements don’t always correlate perfectly with how a patient feels. The meaningful measure of success is whether eating becomes easier, pain decreases, and weight stabilizes over the months following surgery.