A splenic artery aneurysm (SAA) represents a localized bulge or weakening in the wall of the splenic artery, the main blood vessel supplying the spleen. Many SAAs are discovered incidentally during medical imaging performed for unrelated health concerns. While an unruptured SAA might not present immediate symptoms, its potential to rupture transforms it into a life-threatening medical emergency. This rupture can lead to severe internal bleeding, demanding immediate medical attention.
Understanding Splenic Artery Aneurysm
The splenic artery is a major blood vessel that branches off the celiac artery, supplying oxygenated blood to the spleen, a vital organ involved in filtering blood and immune function. An SAA forms when a segment of its wall weakens and expands outward, often due to degeneration of the arterial wall’s elastic and muscular layers.
Several factors contribute to the formation of splenic artery aneurysms. Conditions that increase pressure in the portal vein system, such as portal hypertension, can strain the arterial walls. Pancreatitis, an inflammation of the pancreas, is another contributing factor, as the splenic artery runs along the pancreas and can be affected by the inflammatory process. The hormonal and hemodynamic changes associated with multiple pregnancies are a significant risk factor, particularly for multiparous women. Trauma to the abdomen can also lead to the development of these aneurysms.
The Critical Concern: Aneurysm Rupture
The primary concern with an SAA is its potential to rupture. When an SAA ruptures, the weakened arterial wall tears, causing blood to rapidly leak into the abdominal cavity. This internal bleeding leads to a significant drop in blood volume.
This rapid blood loss can induce hypovolemic shock, a condition where organs do not receive enough blood or oxygen. It can cause organ damage and be fatal if not treated immediately. The mortality rate for a ruptured SAA is high, often exceeding 25% and potentially reaching 75% without prompt intervention. Rupture is more common in certain high-risk groups, including pregnant individuals, where the risk can be as high as 50% during gestation.
Recognizing Warning Signs and Responding
A sudden onset of severe abdominal pain is a primary indicator of rupture, often localized to the upper left quadrant of the abdomen. This pain can be sharp, persistent, and may radiate to the back or shoulder. The rapid internal bleeding can cause systemic symptoms as the body attempts to compensate for blood loss.
Individuals experiencing a ruptured SAA may exhibit signs of shock, including a rapid heart rate, low blood pressure, and clammy skin. Dizziness, lightheadedness, and even fainting can occur due to reduced blood flow to the brain. Pallor, an unhealthy pale appearance, is also a common sign of significant blood loss. If any of these severe symptoms appear suddenly, immediate emergency medical attention is imperative, which typically involves calling emergency services.
Detection and Medical Intervention
Splenic artery aneurysms are frequently discovered incidentally when individuals undergo medical imaging for other conditions. Diagnostic tools such as computed tomography (CT) scans, magnetic resonance imaging (MRI), or ultrasound are commonly used to visualize abdominal structures and can reveal the presence of an SAA. Once an aneurysm is identified, further imaging may be performed to confirm its size, location, and characteristics.
Medical intervention for SAAs varies depending on the aneurysm’s size, symptoms, and the patient’s overall health and risk factors. Small, asymptomatic aneurysms may be closely monitored through regular imaging to track their growth. For larger aneurysms, those causing symptoms, or those in high-risk populations like pregnant individuals, active treatment is usually recommended to prevent rupture. Treatment options include embolization, a procedure that blocks blood flow to the aneurysm, or surgical repair, which may involve removing or bypassing the aneurysm, sometimes necessitating removal of the spleen.