Bilateral vs unilateral pleural drains in tetralogy of Fallot repair

Abstract Objectives: To compare postoperative outcomes after tetralogy of Fallot repair in patients managed with unilateral versus bilateral pleural drains. Methods: In this single-centre retrospective cohort study, patients undergoing complete tetralogy of Fallot repair between 2020 and 2025 were included. Patients with previous complete repair, extracorporeal membrane oxygenation, delayed sternal closure, or chylothorax were excluded. The primary outcome was undrained postoperative pleural effusion on routine chest radiographs. Secondary outcomes were postoperative pleural drain insertion, duration of invasive mechanical ventilation, diuretic score, ICU length of stay, and pleural drain-related complications. Multivariable regression adjusted for repair type, bypass duration, cross-clamp duration, and surgeon. Results: Of 180 patients, 122 (68%) underwent unilateral pleural drain placement and 58 (32%) bilateral placement. Complex repairs were more common in the bilateral group. Undrained pleural effusion was more frequent after unilateral than bilateral pleural drain placement (42.6% vs 5.2%; p < 0.001). Postoperative pleural drain insertion was required in 9 patients (7.4%) in the unilateral group and in none in the bilateral group ( p = 0.06). Pleural drain-related complications were more frequent with bilateral pleural drains, with 4 pneumothoraces requiring intervention versus 1 self-resolving subcutaneous emphysema in the unilateral group ( p = 0.01). In multivariable analysis, bilateral pleural drain placement remained independently associated with lower odds of undrained pleural effusion, but not with duration of mechanical ventilation, diuretic score, or ICU length of stay. Conclusions: Bilateral pleural drains were associated with fewer radiographic pleural effusions but no measurable short-term clinical advantage. Placement should therefore be individualised according to intraoperative findings and local practice.