Constrictive pericarditis is an uncommon but potentially life-threatening disease with various causes. Because of the inflammatory disorder and fibrosis, pericardium becomes inelastic gradually and then inhibits the cardiac filling. This process leads to the diastolic heart failure in the end with unfavorable clinical outcome[12]. Early surgical intervention was reported to play a positive role in reducing mortality rate[13, 14], but the diagnosis seems to be challenging in the early stage. The detection of constrictive pericarditis often relies on the typical clinical symptoms such as dyspnea and clinical signs such as jugular vein distention. Imaging examinations such as chest CT and cardiac MRI are important in the identification of pericardial effusion, calcification and thickening[12, 14, 15]. Meticulous echocardiographic examination is also valuable in the assessment of pericardial condition. Invasive haemodynamic catheterization and pressure measurement were of great significance in the diagnostic confirmation and the evaluation of the constrictive extent[16].
The definitive treatment for constrictive pericarditis is surgical pericardiectomy[17]. The surgical methods are classified as complete pericardiectomy and partial pericardiectomy according to the extent of pericardial resection. Complete pericardiectomy has been proven to be not only associated with lower perioperative mortality[9] but also confer significant long-term survival benefit and clinical functional improvement[10, 18]. Generally, pericardiectomy can be performed through either median sternotomy or left anterolateral thoracotomy, while median sternotomy provides adequate exposure of the right atrium, right ventricle and the vena cava, thus enabling extensive pericardial resection[19].
Despite the undoubtable effectiveness in treating constrictive pericarditis, pericardiectomy is accompanied with high risk of postoperative complication and mortality. An American nationwide outcomes study revealed that the in-hospital complication and mortality rates after pericardiectomy were approximately 48% and 8%, respectively[8]. Also, Tokuda, Y. and his colleagues conducted a nationwide study on the outcome of pericardiectomy for constrictive pericarditis in Japan which showed the operative mortality was 10% and the major morbidity such as bleeding requiring reoperation was 15%[6]. In the respect of long-term outcome, Busch, C. et al. reviewed 97 consecutive patients undergoing surgery for constrictive pericarditis and reported that 1-year and 5-year survival rates were 66.5% and 51.6%, respectively[20]. Another retrospective study including 98 cases showed 1-year, 5-year, and 10-year survival rates were 82.5%, 64.3%, and 49.2%, respectively[21]. Although there are many researches about the surgical treatment for constrictive pericarditis in developed countries, the studies on tuberculous constrictive pericarditis have been limited in recent years due to the decreased incidence of tuberculosis worldwide. However, tuberculosis still remains the major etiology of constrictive pericarditis in developing countries.
We have analyzed the short-term outcome of the patients with tuberculous constrictive pericarditis undergoing complete pericardiectomy over 7 years in our department. Although nearly 40% of patients in our study suffering postoperative complication, there was no mortality within 30 days after surgery. Hypoalbuminemia was the major postoperative complication possibly because of the negative nitrogen balance after surgery. The incidence of low cardiac output was also high enough to warrant attention, because it was proven to be the major contributor to in-hospital death in other studies[3, 22, 23]. In our study, postoperative complication was seemed to be associated with symptom duration, preoperative NYHA functional class, pulse rate, preoperative CVP, pleural effusion and serum sodium, while multivariate analysis eventually proved that poor preoperative NYHA functional class and high preoperative CVP were independent risk factors of postoperative complication, which might provide a valuable reference for preoperative preparation and risk evaluation. We also found postoperative complication significantly delayed the postoperative ICU stay, duration of chest drainage and postoperative hospital stay. Additionally, postoperative complication was the independent risk factor for prolonged ICU stay. It should be emphasized that all patients undergoing complete pericardiectomy in our department were not routinely performed cardiopulmonary bypass, which was also proven to be safe in other studies[24, 25].
There are several limitations in this study. First, this is a single-center retrospective research that inevitably has the selection bias. Secondly, some important data such as duration of anti-tuberculosis medication and body mass index (BMI) are missing due to the retrospective design. Finally, survival outcome includes only the mortality within 30 days after surgery. Long-term outcome is required to be analyzed in the future.