Right heart and pulmonary thromboembolism from extensive splanchnic vein thrombosis after splenectomy for myeloproliferative disease

Complications in the adult asplenic patient: A review for the emergency clinician

BACKGROUND

The spleen performs several important physiologic functions. However, patients can have functional asplenia or have their spleen removed for a number of reasons, which can put them at risk for several dangerous complications.

OBJECTIVE

This narrative review provides a focused evaluation of adult asplenic patients and complications in the emergency departing setting.

DISCUSSION

The spleen plays integral roles in the immune and reticuloendothelial systems and also modulates the inflammatory and coagulation cascades. Asplenia refers to the anatomic or physiologic loss of splenic function, which may be due to trauma, immunological, hematological, or oncological etiologies. Asplenic patients are at risk for several complications including infection, arterial and venous thrombosis, and pulmonary hypertension. Fever in an asplenic patient and overwhelming post-splenectomy infection (OPSI) are medical emergencies with a high mortality and require rapid evaluation and management with broad-spectrum antibiotics. Asplenic patients are at increased risk of arterial thrombosis, such as coronary artery disease, and venous thrombosis including deep venous thrombosis, pulmonary embolism, and splenic and portal vein thrombosis. Management of venous thrombosis includes anticoagulation. Pulmonary hypertension with associated right ventricular dysfunction may also occur in asplenia. These patients require hemodynamic stabilization with an emphasis on inciting causes and treatment of the pulmonary hypertension.

CONCLUSIONS

The spleen is an integral organ involved in several physiologic functions. Asplenia, or absence of spleen function, is associated with severe complications. Knowledge of these complications can improve the care of these patients.

Review of the Association between Splenectomy and Chronic Thromboembolic Pulmonary Hypertension

Recent evidence suggests that there may be a link between splenectomy and the later development of pulmonary hypertension, in particular World Health Organization group IV pulmonary hypertension (chronic thromboembolic pulmonary hypertension). Epidemiological studies have demonstrated an odds ratio as high as 18 for the development of chronic thromboembolic pulmonary hypertension after splenectomy in comparison with matched control subjects who have not undergone splenectomy. The mechanisms governing the association between removal of the spleen and the subsequent development of chronic thromboembolic pulmonary hypertension remain incompletely understood; however, recent advances in understanding of coagulation homeostasis have shed some light on this association. Splenectomy increases the risk of venous thromboembolic disease, a necessary precursor of chronic thromboembolic pulmonary hypertension, by generating a prothrombotic state. This prothrombotic state likely results from a reduction in the removal of circulating procoagulant factors from the bloodstream after splenectomy. Although much is to be learned, circulating microparticles have emerged as the most likely mediator for the development of thrombosis after splenectomy. Apparently because of a reduction in reticuloendothelial cell clearance, microparticle levels are elevated in patients after splenectomy. Elevated circulating microparticle levels have been linked to thromboembolism and pulmonary hypertension in a dose-dependent fashion. It is important for health care providers to be aware of the link between splenectomy and chronic thromboembolic pulmonary hypertension. We are optimistic that clarification of the exact mechanisms that govern this association will yield clinical guidelines and potential treatments.

Intracardiac thrombosis in polycythemia vera

A man in his late 60s presented with symptoms for a few months of itching and head ache after shower. Physical examination was unremarkable except for ruddy complexion and splenomegaly. Complete blood count showed haemoglobin of 18.1 g/dL and haematocrit of 56.6%. To rule out secondary causes of erythrocytosis, such as congenital heart disease with a right to left shunt, a transthoracic echocardiogram was performed, which showed normal left ventricular function with an apical area of dyskinesis and a large left ventricular apical thrombus measuring 3.0 cm×2.0 cm. Further laboratory investigations showed low erythropoietin level and Jak V617F mutation consistent with the diagnosis of polycythemia vera. He was treated with aspirin, enoxaparin, phlebotomy and hydroxyurea with no reported complications during the stay.