Predictors of prolonged pleural effusion after Fontan operation

Prolonged pleural effusion (PPE) is a fairly common condition which has considerable impact on complicated and longer hospital stays in the process of adaptation to new physiology after Fontan surgery. Identifying the patient population which is prone to have pleural effusions is still seeking for an answer. The purpose of this study is to determine the variables that may predict PPE according to the data of 69 patients who underwent Fontan operation between June 2018 -December 2020 and survived to date. Prolonged pleural effusion was defined as the need for a chest tube for more than 7 days. Two patient groups ( with prolonged effusion: PPE group and without prolonged effusion: Non-PPE) were compared in terms of pre, peri and postoperative variables. Moreover, the patients were subdivided into "high risk" and "low risk" groups ( high risk is defined by either of : PVR/SVR ratio> 0.3, mPAP>15 mmHg , VEDP >12 mmHg , TPG>10 mmHg, RPA or LPA Z-score <-2.00) based on the preoperative catheterization data. The most frequent main diagnosis was tricuspid atresia (n: 13, 19%). Among 69 patients, 28 (40%) had PPE whereas 11 (16%) had effusion that lasted longer than 14 days. Ten patients among PPE group (35%) had pulmonary atresia coexistent with the main diagnosis. Fontan operation was performed in 6 patients (8.7%) over the age of 10, and 4 of these patients (67%) had PPE, while in 2 patients PPE lasted longer than 14 days. The most common angiographically obtained "high risk" factor was elevated mPAP (4 patients-14%) in PPE group, and in 2 patients, both of whom had more than one risk factor, effusion lasted longer than 14 days. [ Among numerous variables, statistical significance between two groups was achieved in preoperative mPAP; postoperative albumin, C reactive protein (CRP) levels, lenght of hospital stay, duration of chest tube drainage and amount of effusion per day]. As PPE increases the duration of hospital stay after Fontan operation, early recognition and treatment strategies with routinely used medical protocols remain to be the cornerstone for management of postoperative effusions.