Risk of chronic thromboembolic pulmonary hypertension after splenectomy

The purpose of the clinical study was to evaluate the risk of chronic thromboembolic pulmonary hypertension (CTEPH) after splenectomy and to analyze some biochemical and coagulation parameters.

CTEPH caused by incomplete resolution of thromboemboli and irreversible remodeling of the pulmonary arteries is a progressive, and without treatment a fatal disease. Although the definite etiopathophysiology is not quite perfectly researched, numerous clinical conditions associated with CTEPH as history of pulmonary embolism, infected ventriculoatrial shunts or permanent intravascular devices, high-dose thyroid hormone replacement, malignancy and chronic inflammatory diseases, including osteomyelitis, inflammatory bowel diseases, are well accepted. These factors also include splenectomy.

We performed a prospective follow-up of patients after splenectomy in the period of 5 years (2017-2022). The study population consisted of 62 adult post-splenectomy patients, who were divided into 3 groups based on the cause of the splenectomy - trauma, haematologic diseases, and others. The study population was analyzed in terms of gender, age, cause of splenectomy, blood group, clinical risk factors and thrombophilic conditions. Some basic haemocoagulation parameters and selected coagulation and biochemical parameters were analyzed. All patients underwent screening echocardiography, symptomatic patients repeatedly. In the presence of pulmonary hypertension (PH) unexplained by other diseases, patients underwent ventilation/perfusion lung scan performed to confirm/exclude perfusion defects typical for CTEPH. If PH and perfusion defects persisted despite effective 3-month anticoagulation therapy, patients underwent right heart catheterization to confirm/exclude CTEPH.

The study confirmed a higher incidence of CTEPH after splenectomy compared to published data, the 5-year cumulative incidence was 3.2 %. Other detected clinical risk factors did not affect the incidence of thromboembolism/CTEPH after splenectomy. In our study, the strongest factor in terms of the incidence of thromboembolism/CTEPH after splenectomy was the presence of a thrombophilia detected before the screening echocardiography. Tested haemocoagulation and biochemical parameters in small patient subgroup had no impact on the incidence of thromboembolism/CTEPH - however, the limiting factor was a small patient subgroup.

The results of the study suggest that the incidence of thromboembolism after splenectomy was consistent with the present data, but the incidence of CTEPH after splenectomy was significantly higher. This suggests that post-splenectomy condition may be an independent risk factor for CTEPH and may imply different management of these patients in the future (Tab. 5, Ref. 18).