Unilateral pulmonary edema after minimally invasive mitral valve surgery

Abstract

Introduction Unilateral right-sided pulmonary edema (UPE) is a rare but potentially life-threatening complication after minimally invasive mitral valve surgery (MICS). Methods We will present a case of severe unilateral pulmonary edema with cardiopulmonary instability after mitral valve repair with right minithoracotomy. Results A 45-year-old man (182 cm, 82 kg) was referred to the authors’ hospital for surgical treatment of mitral regurgitation. His medical history included hypertension and chronic obstructive pulmonary disease. Mitral valve repair was performed with plication of prolapsed part of the posterior leaflet and annuloplasty, under general anesthesia. The right lung was decompressed with differential lung ventilation by a double-lumen tracheal tube. Cross-clamp time was 128 min, and CPB time was long (193 min). Three hours after the surgery, oxygen saturation suddenly dropped to approximately 90 %, and frothy pink sputum was blast out from the tracheal tube. Chest radiograph showed unilateral right-sided massive infiltrate. No evidence of residual mitral insufficiency was detected by trans-thoracic echocardiography. Arterial pressure was maintained with high dose norepinephrine. Cardiac output was maintained with epinephrine and dobutamine, which were gradually attenuated within the first postoperative day. Mechanical ventilation was performed with high PEEP and high FiO2 (12 mmHg, 100 %, respiratory rate 16/min, tidal volume 5 ml/kg) by assist/control mode to maintain oxygenation. Pulse steroid therapy was applied for 3 days. Urine output was maintained at least 50 ml/h through the perioperative period. Patient was extubated 21 h after surgery. On the postoperative day 2, chest radiography showed reduced right-sided infiltration. Patient was discharged home on the 8th postoperative day. Discussion The reasons of unilateral right-sided pulmonary edema are multifactorial, including complete lung collapse and ischemic reperfusion injury, systemic inflammatory reaction and extracorporeal circulation, level of mean pulmonary arterial pressure, chronic obstructive pulmonary disease, and increasing CPB time. Perioperative medical team should be aware of the heightened perioperative risk of UPE during MICS.