Successful rescue of a patient with cardiac arrest from massive pulmonary embolism complicated by giant hepatic hemangioma rupture following ECMO and catheter-directed therapy

Massive pulmonary embolism (MPE) is a life-threatening condition with high mortality.^[1] Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) provides immediate hemodynamic support.^[2] Catheter-directed thrombolysis (CDT) and thrombectomy are being increasingly used as alternatives to systemic thrombolysis to reperfuse pulmonary vessels, especially in patients with contraindications or those on ECMO.^[3] Here, we report a case of MPE presenting with cardiac arrest that was successfully managed with extracorporeal cardiopulmonary resuscitation (ECPR) and CDTs; however, it was complicated by rupture of a giant hepatic hemangioma leading to hemorrhagic shock. This case highlights the importance of recognizing potential bleeding sources in ECPR with antithrombotic and/or anticoagulant therapy.

A 50-year-old woman presented with recurrent dizziness and weakness for 7 d, which had worsened over the previous hour. She reported increased menstrual flow occurring 7 d prior. Her medical history included uterine fibroids with irregular vaginal bleeding for 10 years and a hepatic hemangioma for 5 years without medical follow-up. She reported no regular medications or allergies.

On arrival, vital signs included hypotension (89/51 mmHg [1 mmHg=0.133 kPa]), bradycardia (49 beats/min), and tachypnea (38 breaths/min), with a pulse oxygen saturation (SpO₂) of 89% on room air. Physical examination revealed no abdominal pain; however, a pelvic mass was palpated. A gynecological examination revealed no vaginal bleeding. The patient quickly developed cardiac arrest. Cardiopulmonary resuscitation (CPR) was immediately initiated with intubation. After 10 min of resuscitation, no spontaneous circulation returned, and the pupils dilated to 5 mm without a light reflex. Ultrasound revealed no pulmonary infiltrates or effusions but demonstrated right ventricular dilatation with a D-shaped left ventricle. Acute cor pulmonale was diagnosed. An emergency ECMO team, which was available 24/7, rapidly initiated VA-ECMO 23 min after cardiac arrest, after which spontaneous circulation returned, and the pupils gradually normalized. Before the guidewire was inserted for ECMO catheterization, 2,000 units of unfractionated heparin were administered.

Laboratory results obtained prior to the cardiac arrest revealed a hemoglobin concentration of 12 g/dL, a negative troponin concentration (<0.05 ng/mL), and a D-dimer concentration >200,000 μg/L. Based on the right ventricular strain and markedly elevated D-dimer levels, MPE was diagnosed as the cause of the cardiac arrest. The patient was transferred to the cardiac catheterization laboratory for pulmonary angiography. Angiography revealed contrast-filling defects with partial obstruction of the right pulmonary artery and complete obstruction of the left pulmonary artery (Figure 1A), with a high systolic pulmonary artery pressure (SPAP) of 79 mmHg. According to the low plasma fibrinogen concentration (0.6 g/L), the risk of bleeding was too high to select systemic thrombolysis. CDT with tenecteplase (4 mg bolus followed by three additional doses for a total amount of 16 mg) was administered into the thrombus, thereby reducing the SPAP to 45 mmHg with partial distal vessel visualization. Catheter-directed thrombectomy using the AngioJet system (Boston Scientific) was then performed to fragment and aspirate the residual thrombi. The SPAP subsequently decreased to 32 mmHg, and left pulmonary artery perfusion was restored (Figure 1B). Hemodynamics rapidly improved following the procedure.

Figure 1. Pulmonary angiography and catheter-directed therapy (CDT) for pulmonary embolism. A: contrast-filling defects in the right and left pulmonary arteries (PAs) with partial obstruction of the right PA and complete obstruction of the left PA. The green arrows indicate the location of the thrombi; B: satisfactory restoration of bilateral pulmonary perfusion after CDT; C: CT lung angiography on day 3 after CDT, the green arrows show the residual thrombi in the right and left PAs. CT: computed tomography.

The patient was transferred to the intensive care unit (ICU) and was observed to be hemodynamically stable without the use of vasopressors. On ICU admission, the abdominal examination revealed a benign lesion, along with a hemoglobin concentration of 10 g/dL. ECMO was continued with unfractionated heparin infusion at 500 U/h. Abdominal ultrasound revealed a hypoechoic liver mass measuring 10 cm ×5 cm and a pelvic mass, with no effusion being observed.

Three hours later, the patient’s blood pressure decreased. ECMO flow became unstable with venous line shaking despite volume resuscitation. The abdomen became distended, and the patient’s hemoglobin concentration decreased to 3.5 g/dL. Repeat abdominal ultrasound showed abundant peritoneal effusion (Figure 2A). An emergency exploratory laparotomy revealed 4,000 mL of bloody fluid in the abdominal cavity. The source of bleeding was determined to be a rupture of a giant hepatic hemangioma located in segments IV, V, and VI (Figure 2B, C). Surgical resection of the hemangioma (9 cm×5 cm×3 cm) and cholecystectomy were performed. Hemodynamics stabilized after surgery and massive transfusion.

Figure 2. Bleeding complication caused by a hepatic hemangioma. A: abdominal ultrasound showing abundant peritoneal effusion; B: surgical field view. The blue ellipse indicates rupture of the hepatic hemangioma; the rupture and hemorrhage caused the hemangioma to collapse; C: pathological findings of the hepatic hemangioma; D: adjacent anatomical structures between the liver, ribs and sternum.

Antiphospholipid syndrome and tumors were excluded as causes of the PE. Thrombophilia testing revealed a heterozygous PROC mutation (c.565C>T) in chromosome 2, thus resulting in an arginine-to-tryptophan substitution at position 189 in the protein C sequence. This mutation is the most common cause of protein C deficiency in Chinese individuals.^[4] The serum protein C concentration was observed to be lower, thereby confirming protein C deficiency. However, we did not test the activity of protein C because of equipment limitations.

Postoperatively, the patient’s condition rapidly improved. She was weaned from ECMO on day 2 and from mechanical ventilation on day 9, after which she was transferred to the rehabilitation department. At the 6-month follow-up, she was conscious and independent in activities of daily living, with a cerebral performance category score of 2 indicating a good neurological outcome.

The 2023 American Heart Association guidelines recommend ECPR for select patients who present with refractory cardiac arrest when this technique is available within an appropriately trained system.^[5] Our institution’s emergency physician-led ECMO team achieved cannulation 23 min after arrest, which contributed to the observed favorable neurological outcome.

The finding of right ventricular dilatation with a D-shaped left ventricle (combined with elevated D-dimer levels) established the immediate diagnosis of MPE. Ultrasound is invaluable in the determination of undifferentiated shock and cardiac arrest.^[6]

The choice of a pulmonary arterial reperfusion strategy requires careful risk-benefit assessment. Systemic thrombolysis is associated with a significant bleeding risk, particularly in patients on ECMO with therapeutic anticoagulation.^[3] CDT allows for the local administration of reduced-dose thrombolytics, thus potentially decreasing bleeding complications. In this patient, a reduced dose of tenecteplase (approximately one-third to one-half of the systemic dose) was administered, thereby resulting in hemodynamic improvement. Recent studies have suggested that catheter-based therapies are associated with reduced major bleeding rates compared to systemic thrombolysis.^[3,7]

Delayed rupture of a hepatic hemangioma is a rare but catastrophic complication.^[8] Moreover, spontaneous rupture of hepatic hemangiomas is a rare event. Rupture during anticoagulation has been reported;^[9] however, rupture following CDT in a patient on ECMO has not been previously described. Several factors may have contributed to this phenomenon: (1) anticoagulation with heparin and/or tenecteplase; (2) possible hepatic congestion from right heart failure, which increases the risk of hemangioma rupture; and (3) potential chest compression-related trauma to hepatic hemangioma during CPR, given the hemangioma’s location adjacent to the ribs and sternum (Figure 2D). The rupture that occurred in this case may have been related to injury due to impact sustained during CPR.

The mortality rate is high among patients with high-risk PE associated with hemodynamic collapse. Effective management requires close multidisciplinary collaboration involving emergency physicians, intensivists, interventional cardiologists.^[2] This case also highlights the importance of a history of giant hepatic hemangioma, which increases the risk of rupture during chest compressions.

Funding: None.

Ethical approval: Written informed consent was obtained from the patient for publication of this case report. This study was approved by the Ethics Committee of the Second Affiliated Hospital of Zhejiang University School of Medicine.

Conflicts of interest: The authors declare no conflicts of interest.

Contributors: FR wrote the article. FR and GJZ collected and interpreted the data. All authors critically revised the manuscript.