Chest compression-related fatal internal mammary artery injuries manifesting after venoarterial extracorporeal membrane oxygenation: a case series

A 65-year-old Asian man had a history of myocardial infarction and atrial fibrillation, and was receiving dual antiplatelet and warfarin treatment. After collapsing at a concert, he received immediate bystander CPR as well as six automated external defibrillator shocks before the emergency medical service (EMS) arrived; he was then transported to our hospital. His rhythm was asystole at the time of admission, and VA-ECMO commenced 45 minutes after his cardiac arrest because conventional CPR did not result in ROSC. Contrast-enhanced CT after starting VA-ECMO revealed bilateral multiple rib fractures, a sternum fracture, and right pleural effusion without contrast extravasation (Fig. 1a). Transcatheter arterial embolization (TAE) was not indicated; coronary angiography (CAG) was performed for suspected cardiogenic cardiac arrest based on the prehospital shockable rhythm. His left circumflex artery was completely occluded, and percutaneous coronary intervention (PCI) was attempted but failed because of strong calcification. Repeat contrast-enhanced CT was performed because of unstable blood flow during the VA-ECMO, and our patient exhibited a gradual decrease in his hemoglobin (Hb) levels from 10.8 g/dL at admission to 8.4 g/dL 2 hours later. CT revealed contrast extravasation at his mediastinum and right anterior chest wall, with increases in the sizes of the hematomas (Fig. 1b). TAE was performed for his right IMA and right ICA using n-butyl cyanoacrylate (NBCA) 560 minutes after his cardiac arrest. His activated partial thromboplastin time was > 130 seconds before TAE. He subsequently died 2 hours after TAE despite receiving 26 red blood cell units, 16 fresh frozen plasma units, and three packs of cryoprecipitate.

A 68-year-old Asian man was transported to another hospital by the EMS because of chest pain. Ventricular fibrillation (VF) was noted on his arrival, and conventional CPR was performed immediately. He achieved ROSC after four defibrillation shocks, and was subsequently transferred to our hospital for post-cardiac arrest care. An intra-aortic balloon pump (IABP) was inserted at our hospital for cardiogenic shock, and CAG was also performed, revealing total occlusion of his left anterior descending artery. He was diagnosed as having acute myocardial infarction and underwent successful PCI. Chest radiography did not reveal any traumatic abnormalities (Fig. 2a), and his hemodynamics were maintained using IABP and a continuous infusion of noradrenalin. Minimal change was observed in his Hb levels (admission, 13.5 g/dL; 6 hours later, 13.3 g/dL). Two days after admission, he suddenly deteriorated, and VA-ECMO was initiated for suspected cardiogenic shock. However, his Hb level decreased to 5.3 g/dL, which indicated hemorrhagic shock. Ultrasonography and chest radiography revealed massive left pleural effusion (Fig. 2b), and a massive hemothorax was diagnosed after inserting a chest drainage tube. The blood flow from the drainage tube was > 200 mL/hour for several hours, and contrast-enhanced CT was performed to identify the source of the bleeding. Contrast extravasation was noted behind his left sixth rib, as well as hematoma at his mediastinum and hemothorax without rib fracture (Fig. 2c). Thoracotomy was performed to achieve hemostasis 48 hours after cardiac arrest. Although the bleeding appeared to originate from his left ICA, it was difficult to stop; therefore, an artery involved with the adjacent rib was also ligated. However, this procedure did not stop the bleeding from the left chest drain, and angiography at 8 hours after the thoracotomy revealed bleeding from his left IMA. TAE was performed using microcoils and gelatin sponge pledgets, but did not control the bleeding. He subsequently died because of hemorrhagic shock 8 hours after the TAE.

A 56-year-old Asian man (an in-patient) had undergone an emergency graft implantation for a type A aortic dissection. On the eighth day post-surgery, he lost consciousness and experienced cardiac arrest that was witnessed by a surgeon in the general ward. He experienced refractory VF after conventional CPR, and VA-ECMO was started 28 minutes after the cardiac arrest. CAG revealed a thrombus between the aortic graft and the left main trunk of his coronary artery. Blood flow in his coronary artery improved after thrombus aspiration and balloon angiography. Contrast-enhanced CT after the PCI revealed extravasation and a hematoma at the mediastinum (Fig. 3a). Angiography revealed that the extravasation was proximal to his left IMA (Fig. 3b). Although TAE was performed using NBCA at 313 minutes after his cardiac arrest, the spasm persisted and ECMO flow could not be maintained at that time. He died 41 minutes after the TAE.

A 62-year-old Asian man was transported to our hospital by the EMS because of pulseless electrical activity after receiving bystander CPR. VF was documented at the admission, and VA-ECMO was started for refractory VF 55 minutes after his cardiac arrest. Contrast-enhanced CT revealed a sternal fracture and a retrosternal hematoma with contrast extravasation (Fig. 4a). CAG was initially performed because the VA-ECMO flow was maintained and revealed 90% stenosis of his left main trunk. He was diagnosed as having acute myocardial infarction and underwent successful PCI. IABP was initiated to treat cardiogenic shock during the VA-ECMO. He exhibited a gradual decrease in his Hb levels: admission, 16.3 g/dL; 4 hours later, 14.2 g/dL. Repeat contrast-enhanced CT was performed because of the hematoma and contrast extravasation, and revealed new contrast extravasation behind his right fifth costal cartilage and beside his sternum, as well as growing hematomas in the retrosternal space (Fig. 4b). Angiography revealed extravasations at his bilateral IMAs, and TAE was performed using NBCA at 327 minutes after his cardiac arrest (Fig. 4c). The TAE successfully decreased the IMA flow and the extravasations disappeared. The VA-ECMO and IABP were tapered on day 7 and day 11 post-admission, respectively. He was subsequently transferred to another hospital for rehabilitation on day 123 at which point his Glasgow–Pittsburgh cerebral performance category was 3.

A 62-year-old Asian man was transported to our hospital by the EMS because of VF after four defibrillation shocks. VA-ECMO was started for refractory VF at 40 minutes after his cardiac arrest. Contrast-enhanced CT before the CAG revealed right rib fractures, a sternum fracture, and a mediastinal hematoma with contrast extravasation (Fig. 5a). CAG did not reveal any coronary artery stenosis, and selective right IMA angiography subsequently identified the extravasation (Fig. 5b). Artery embolization was performed using gelatin sponge pledgets and microcoils at 181 minutes after his cardiac arrest, and IABP was started after the TAE. He was a heavy drinker and was diagnosed as having VF that was caused by hypomagnesemia (serum magnesium level of 1.7 mg/dL at admission) and hypokalemia (serum potassium level of 2.6 mmol/L at admission). The VA-ECMO and IABP were tapered on days 2 and 4 post-admission, respectively. After implantation of a cardiac defibrillator, he was transferred to another hospital for rehabilitation on day 88, when he exhibited a cerebral performance category of 3.