A 59-year-old female with a body mass index (BMI) of 28.4 kg/m2 underwent elective cemented knee replacement surgery. With a medical history of arterial hypertension, intraoperative analgesia was achieved with spinal anaesthesia (3.4 ml of bupivacaine 0.5%) and sedation with propofol (2.4 mg/kg/h). During the first three postoperative days (POD), her recovery proceeded without any abnormalities. Prophylactic anticoagulation was achieved with weight-adjusted low-molecular weight heparin (LMWH, certoparin 3000 I.E. s.c. per day). On POD 4 the patient developed dyspnoea during mobilisation. The subsequent CT scan revealed bilateral PE; therefore, the patient was transferred to the intermediate care unit. On admission, the patient was awake, responsive and did not present dyspnoea in supine position. Anticoagulation was performed with a bolus of 5000 I.E. of heparin, followed by enoxaparin (2 × 0.8 mg s.c. per day). In good overall condition and with a corresponding PESI-Score of 59 (Class I, mortality risk 0% -1.6%), the patient was readmitted to the general ward in the morning of POD 5. In the evening, the patient collapsed again and presented with dyspnoea and tachycardia. Transthoracic echocardiography revealed severe RV dilatation (Fig. 1a), tricuspid regurgitation, decreased tricuspid annular plane systolic excursion (TAPSE, 11 mm) and flattened interventricular septum (Fig. 1b). Due to acute cardiac decompensation and pulseless ventricular tachycardia, cardiopulmonary resuscitation (CPR) and intubation had to be performed. Haemodynamic stabilisation could only be achieved after implantation of a VA-ECMO. Noradrenaline was given with a maximum rate of 0.06 µg/kg/min. Levosimendan (0.1 µg/kg/min) ensured additional inotropic support. The subsequent angiography showed bilateral occlusion of the main pulmonary arteries (Fig. 2).
According to the PESI-Score, the patient was now classified in Class V (very high mortality risk, 10% – 24.5%), underlining the need for urgent reperfusion therapy. However, due to the high bleeding risk after major surgery and according to the European guideline, systemic thrombolysis was relatively contraindicated. The possibility of surgical embolectomy was withdrawn because of the reported high mortality rates after cardiac arrest and due to the highly invasive extent of the procedure. As a consequence of the interdisciplinary team discussion, involving cardiothoracic surgeons, cardiologist, radiologists and intensive care physicians, ultrasound-accelerated catheter-directed thrombolysis (EkoSonic Endovascular System [EKOS Corporation, a Boston Scientific Company, Bothell, WA, USA]) was performed. Via the right femoral vein one catheter was inserted into the right pulmonary artery. Subsequently, another catheter was brought to the left pulmonary artery via the left jugular vein (Fig. 3). After the ultrasound emission, each catheter released 1 mg/h of rtPA during the first five hours, followed by 0.5 mg/h rtPA for ten hours. Therapeutic anticoagulation was now established with argatroban (0.5 µg/kg/min) and partial thromboplastin time (aPTT) was targeted at 60–70 s. Due to stabilisation of the RV-function, ECMO support was ended three days after the implantation. During that time, the patient received 1.5 l red blood cell concentrate, 0.4 l fresh frozen plasma and 0.4 l albumin 20%. A further CT scan revealed regression of thrombotic burden (Fig. 4), showing only small clots in the lobar arteries. Due to respiratory and haemodynamic stabilisation, the patient was extubated one day later. Subsequently, the therapeutic anticoagulation was changed to an oral treatment with apixaban (2 × 10 mg p.o. for one week, 2 × 5 mg p.o. subsequently). Ten days later, the patient was transferred to the general ward, from which she was discharged to ambulatory treatment in good condition after nine days.
A 59-year-old female with a BMI of 23.5 kg/m2 suffering from renal cell carcinoma (RCC) metastasis in the right lobe of the liver, underwent elective right hemihepatectomy. Medical history included RCC that was treated with nephrectomy, splenectomy and pancreatic left resection in 2003. Currently, the patient presented in a good condition. After the uneventful surgery she was transferred to the intensive care unit. Intermittent pneumatic compression (Kendall SCD 700, Cardinal Health, Ireland) was used as deep-venous thrombosis prophylaxis. Prophylactic anticoagulation was first achieved with heparin (400 I.E./h) and was subsequently changed to certoparin (3000 I.E. s.c. per day). Her recovery proceeded without any abnormalities; thus, she was discharged to the general ward at POD 1. One day later, she collapsed during mobilisation and was immediately transferred to the radiology department. On the way, she became haemodynamically unstable and CPR was started. Orotracheal intubation was performed and the patient was transferred to the intensive care unit, where a VA-ECMO was implanted. After haemodynamic stabilisation, a CT scan was performed and revealed bilateral massive PE spreading through all lobar and segmental arteries. Due to the large thrombotic burden and a massive derangement of coagulation, an interdisciplinary decision, involving cardiothoracic and general surgeons, cardiologists, radiologists and intensive care physicians, was made for interventional treatment. Pulmonary angiography and consecutive catheter implantation (EkoSonic Endovascular System [EKOS Corporation, a Boston Scientific Company, Bothell, WA, USA]) in each pulmonary artery allowed USAT. The left pulmonary artery catheter was inserted through the left femoral vein, and the right pulmonary artery was reached through the right jugular vein. During the following 12 hours, 12 mg of rtPA were administered (0.5 mg/h/catheter). After 6 hours, an additional CT scan already revealed partial recanalisation of the lobar arteries. Noradrenaline was administrated at a maximum of 0.19 µg/kg/min and inotropic support was delivered using low-dose dobutamine (3 µg/kg/min). During USAT with rtPA and therapeutic anticoagulation with argatroban (at a maximum of 0.46 µg/kg/min, targeted aPTT 60–80 s), a major abdominal bleeding from the operation’s area occurred. The bleeding had to be treated in the operating theatre twice, and the patient received a total of 4.9 l red blood cell concentrate, 4.3 l fresh frozen plasma, 0.9 l platelet concentrate, 6 g fibrinogen, 1250 I.E. factor XII concentrate and 1500 I.E. prothrombin complex concentrate. Subsequently, examinations of RV function were performed with transoesophageal echocardiography (TEE). A daily improvement in biventricular function was recognised; as a result, the ECMO was removed after four days. Subsequently, the patient went through prolonged intensive care treatment, including tracheotomy, dialysis and complicated weaning. An empyema of the lower lobe due to a lung infarction-associated pneumonia had to be treated surgically before the patient’s condition improved. She was transferred to the general ward 41 days after admission to the intensive care unit and was discharged to rehabilitation two weeks later.