Patients who undergo splenectomy, or surgery to remove the spleen, increase their risk of pulmonary hypertension (PH), myocardial infarction and stroke. That’s the conclusion of a study, “Risk of cardiovascular events and pulmonary hypertension following splenectomy – a Danish population-based cohort study from 1996-2012,” that appeared in the journal Haematologica.
U.S. doctors perform about 22,000 splenectomies a year, according to the National Hospital Discharge Survey, mostly on patients with spleen injuries or hematological disorders. Short-term risks include postoperative infections, bleeding and blood clotting in deep veins. In the long term, patients face a higher risk of pneumococcal blood infection, otherwise known as sepsis or bacteremia.
Researchers have also found an increased long-term risk of atherosclerotic events and PH in post-splenectomy patients. Because they lose their spleen’s filtering function, such patients cannot eliminate damaged cells from the bloodstream, increasing the risk of coagulation.
In order to prevent patients from having post-splenectomy complications, doctors need to know if the increased cardiovascular risk for PH, myocardial infarction and stroke are due to the surgery itself, or to the diseases underlying the splenectomy.
To answer that question, researchers in Denmark identified 5,306 patients who had splenectomies and 11,651 patients who were not splenectomized but were matched by age, sex and underlying disease. Also included in the study were 53,060 people from the general population. Researchers compared the risk of PH, myocardial infarction and stroke among these groups.
Among the splenectomized patients studied, 19.5 percent had traumatic rupture of the spleen, 16.6 percent abdominal cancers, 7.9 percent hematopoietic cancers and 7.1 percent idiopathic thrombocytopenic purpura. In total, 37.4 percent of the patients had another underlying disease and could not be matched.
After five years of follow-up, researchers found that splenectomized patients had an increased risk of PH (3.25%), myocardial infarction (1.24%) and stroke compared to the general population.
When compared to the disease-matched group, splenectomized patients did not have a significantly higher risk of myocardial infarction or PH. However, after 10 years of follow-up, their stroke risk was slightly higher (4.9%) than in the disease-matched patients (4.0%). In addition, researchers found that splenectomized patients had a 50 percent higher risk of ischemic stroke and a 30 percent increased risk of hemorrhagic stroke compared with those in the disease-matched group.
Researchers cannot explain the increased risk of stroke following splenectomy, though their study urges closely following such patients for possible cardiovascular complications.