The patient arrived with a formidable list of problems. He had long-standing dilated cardiomyopathy, a condition in which the heart muscle stretches and weakens until it can no longer pump effectively. He also carried a cardiac resynchronization therapy defibrillator, a device implanted under the skin with wires, or leads, running through veins directly into the heart. That device had become infected. Blood tests revealed methicillin-sensitive Staphylococcus aureus, a virulent bacterium circulating in his bloodstream, and the pocket of tissue housing the generator was itself infected. He was in respiratory failure, his kidneys were shutting down, and his clinical picture was consistent with mixed septic and cardiogenic shock, a combination of infection-driven and pump-failure-driven collapse that carries a grave prognosis.

Transthoracic echocardiography, an ultrasound scan of the heart, showed just how precarious his situation was. The left ventricle, the main pumping chamber, was severely dilated, and its ejection fraction, the fraction of blood expelled with each beat, was a mere 10 percent. A healthy heart ejects roughly 55 to 70 percent. At 10 percent, the chamber was functioning at a level at which even minor procedural stress can trigger irreversible collapse. The defibrillator lead, moreover, had been in place for 17 years. Older leads bind to the vessel walls and heart tissue with dense fibrous scar, and extracting them in a patient with such profound ventricular dysfunction was judged to be extremely high risk.

The standard of care for cardiac device-related infective endocarditis is unambiguous: complete removal of all implanted hardware, because leaving any infected foreign material behind allows the infection to persist and relapse. International consensus documents from the European Heart Rhythm Association and the American Heart Association both emphasize that incomplete extraction is associated with recurrent infection and worse outcomes. Yet the same guidelines acknowledge the central paradox that the Japanese team confronted. Transvenous lead extraction, in which the leads are freed from scar tissue and pulled out through the veins, can cause major cardiac and vascular complications, and patients in shock tolerate those complications poorly. Registry data from the ESC-EHRA ELECTRa collaboration have documented that major complications after transvenous lead extraction are rare but often catastrophic, particularly in fragile patients.

The team’s solution was to buy hemodynamic insurance before touching anything. They implanted an Impella 5.5, a microaxial flow pump roughly the width of a pencil, through the right subclavian artery, the vessel running beneath the collarbone that gives access to the axillary region referenced in the report’s title. The Impella 5.5 is a catheter-mounted rotor that spans the aortic valve and continuously draws blood out of the left ventricle, propelling it into the ascending aorta. Unlike older temporary pumps, the 5.5 can deliver up to about 5.5 liters of flow per minute, close to the entire output of a healthy heart at rest, and it is designed for support lasting weeks rather than hours. In this patient, it effectively took over the work of a ventricle that could barely function, providing forward flow independent of the diseased muscle.

With the pump running, the surgeons performed the first stage of source control: surgical drainage of the infected generator pocket. This initial step reduced the bacterial burden at the most accessible site of infection without subjecting the heart to the traction forces of lead removal. Only after the patient had stabilized on the pump, and after his requirement for vasoactive drugs, the powerful medications used to constrict blood vessels and maintain blood pressure in shock, had fallen, did the team proceed to the definitive procedure. On hospital day 6, they extracted all of the leads transvenously, with the Impella 5.5 still providing full circulatory support and a cardiovascular surgical team standing by as backup.

The extraction itself illustrated precisely why the pump had been worth the trouble. As the surgeons applied traction to the 17-year-old defibrillator lead, the pulmonary artery pressure transiently decreased, a sign that the mechanical stress of freeing the lead was disturbing cardiac function. In an unsupported patient with a 10 percent ejection fraction, such a perturbation could have cascaded into systemic collapse. Here, it did not. Sustained hemodynamic collapse never occurred, because the microaxial pump maintained perfusion to the brain, kidneys, and other vital organs throughout the procedure. The pump acted as a hemodynamic shock absorber, smoothing over the transient insults that lead extraction inevitably inflicts on a failing heart.

The recovery that followed was equally instructive. The patient received a prolonged course of intravenous antibiotics, the standard treatment once all infected hardware has been removed and the bloodstream has been sterilized. Blood cultures remained negative, confirming that the bacteremia had been eradicated. His kidneys recovered sufficiently that continuous hemodiafiltration, a form of around-the-clock renal replacement therapy used in critically ill patients, could be discontinued. This end-organ recovery is not a trivial footnote; it is often the deciding factor in whether a patient can ever qualify for advanced therapies. Once he was stable and infection-free, he was transferred to an advanced heart failure center, where surgeons successfully implanted a durable left ventricular assist device, an implanted pump designed to support the failing heart for years.

The case report thus describes what the authors call a bridge-to-bridge strategy: a temporary pump that stabilizes a patient through the acute infectious crisis, enabling staged source control and high-risk lead extraction, and then sustains end-organ recovery long enough for the patient to become a candidate for durable mechanical circulatory support. The Impella 5.5 has an expanding evidence base for extended support, with prior studies documenting support durations beyond 50 days as a bridge to heart transplantation and analyzing outcomes of extended support including transitions to extracorporeal membrane oxygenation. What this report adds is a specific new indication: using axillary Impella support not primarily for cardiogenic shock from a heart attack, the setting in which microaxial pumps have been most intensively studied in recent randomized trials, but as a platform for infection control in device-related endocarditis complicated by end-stage heart failure.

The authors are careful to frame this as a single-patient experience, and the report itself notes that the approach may be appropriate for carefully selected patients rather than as a universal strategy. Microaxial pump support carries its own risks, including vascular complications at the access site, hemolysis, and bleeding, and prolonged support demands intensive surveillance. Sepsis-induced cardiomyopathy, in which infection itself further depresses heart function, adds another layer of complexity to cases like this one. Still, the trajectory of this patient, from mixed septic and cardiogenic shock with multi-organ failure to successful durable left ventricular assist device implantation, demonstrates a principle that is likely to influence how such cases are managed going forward. When the cure for an infection requires a procedure the heart cannot tolerate, temporarily replacing the heart’s work may be the step that makes the cure possible. For clinicians confronting the growing population of patients with infected cardiac devices and failing ventricles, this case provides a concrete, technically detailed template for doing exactly that.

Subject of Research: Axillary Impella 5.5 mechanical circulatory support as a bridge through staged source control and lead extraction in cardiac device-related infective endocarditis with end-stage heart failure

Article Title: Axillary microaxial flow pump support for stepwise source control and bridge to durable left ventricular assist device therapy in cardiac device–related infective endocarditis

Article References: Tamura, Y., Nakahara, S., Saito, M., Torikai, K., Toda, K., & Taguchi, I. (2026). Axillary microaxial flow pump support for stepwise source control and bridge to durable left ventricular assist device therapy in cardiac device–related infective endocarditis. Journal of Artificial Organs, 29(4), Article 68. https://doi.org/10.1007/s10047-026-01599-y

Image Credits: AI Generated

DOI: 10.1007/s10047-026-01599-y

Keywords: Impella 5.5, cardiac device-related infective endocarditis, transvenous lead extraction, mechanical circulatory support, dilated cardiomyopathy, left ventricular assist device, cardiogenic shock, Staphylococcus aureus, source control, cardiac resynchronization therapy defibrillator, microaxial flow pump, heart failure

The clinical picture on presentation was dire. Acute severe mitral regurgitation had produced extreme respiratory failure despite maximal ventilatory support: while breathing pure oxygen, the patient’s arterial blood showed a pH of 7.144, a partial pressure of oxygen of only 48 mmHg, and a partial pressure of carbon dioxide of 101 mmHg. Those numbers describe profound, life-threatening hypoxemia and hypercapnia, the biochemical signature of lungs so waterlogged and failing that gas exchange had nearly collapsed. Fulminant pulmonary edema of this kind, driven by the sudden backflow of blood through an incompetent mitral valve, typically leaves clinicians with a narrow and dangerous window in which to act.

The standard emergency answer for such patients is often veno-arterial ECMO, in which blood is drained from the venous system, oxygenated outside the body, and returned to the arterial circulation, simultaneously supporting the heart and lungs. But the authors highlight a well-recognized paradox: VA-ECMO can worsen pulmonary congestion in patients with a failing left ventricle. By returning oxygenated blood to the aorta, it increases the afterload against which the damaged left ventricle must pump, which can push blood backward into the lungs and aggravate the very edema the therapy is meant to buy time against. Recent literature, including a 2024 position paper on dual-circulation physiology during venoarterial ECMO and multicenter data linking left ventricular unloading to lower mortality in cardiogenic shock, has sharpened attention on this problem and on strategies to relieve the loaded ventricle.

The surgical team proceeded with emergency mitral valve replacement under cardiopulmonary bypass. When the operation ended, however, the heart could not be weaned from the bypass machine: severe pulmonary edema and post-cardiotomy shock conspired to keep the ventricle too weak and the lungs too compromised for independent circulation. Rather than defaulting to VA-ECMO, the surgeons made a deliberate split decision. They implanted an Impella 5.5, an axial-flow catheter-mounted pump, directly into the ascending aorta through a prosthetic graft, positioning it across the aortic valve so it could draw blood out of the left ventricle and deliver it antegrade into the systemic circulation. Then they added veno-venous ECMO, which drains deoxygenated blood from the venous side and returns it oxygenated to the veins, supporting only the lungs.

The physiological logic of this combination is what makes the case compelling. The Impella 5.5 provides left ventricular unloading and forward systemic flow, reducing the pressure that would otherwise be transmitted back into the pulmonary vasculature, while VV-ECMO takes over gas exchange without adding any arterial afterload at all. In effect, the circulation and the respiration were decoupled and managed independently, avoiding the differential hypoxemia problem known as harlequin syndrome, in which poorly oxygenated blood ejected by the native heart mixes with oxygenated ECMO return in patients on VA-ECMO. The authors argue that this decoupled strategy may be an effective option for selected patients suffering concomitant severe respiratory and circulatory failure, particularly when VA-ECMO risks compounding pulmonary congestion.

The early postoperative course was rocky but revealing. The patient initially required substantial vasoactive and inotropic drug support to maintain blood pressure, a reflection of both the stunned post-cardiotomy myocardium and the inflammatory burden of prolonged critical illness. Serum lactate, a biochemical marker of inadequate tissue perfusion, peaked transiently at 10.9 mmol/L on postoperative day one, a level indicating significant anaerobic metabolism. Crucially, however, systemic perfusion was maintained throughout, and as the ventricle recovered, the team was able to stabilize the circulation on Impella-mediated antegrade flow alone, without ever converting to VA-ECMO or the hybrid V-AV configuration that many centers would have reached for in a similar situation.

Respiratory recovery followed a parallel and equally instructive trajectory. Under VV-ECMO-supported lung rest, with the membrane lung shouldering the work of oxygenation and carbon dioxide removal, and under an intensive diuretic regimen to strip away the excess lung water, the patient’s respiratory function improved progressively. Bilateral pulmonary opacities on imaging, the radiographic shadow of the edema, gradually cleared. VV-ECMO was removed on postoperative day three, a remarkably short run that suggests the lung injury, while fulminant, was largely hydrostatic and reversible once the circulatory derangement was corrected. The Impella 5.5 was explanted on postoperative day six as ventricular function recovered.

The outcome was a full survival: the patient was discharged on postoperative day 46 without any neurological sequelae, an outcome that would have been considered improbable at the moment of presentation, when his blood gases were incompatible with sustained life on conventional support. For a case report, the message is less about a single heroic save than about a reproducible physiological principle. The authors position the combination as a way to sidestep the afterload penalty of VA-ECMO while still providing both pump function and gas exchange, drawing on established techniques for direct aortic Impella implantation that allow the device to be placed surgically with secure fixation.

The report also underscores how rapidly the mechanical support landscape is evolving. The Impella 5.5, originally developed as a percutaneous left ventricular assist device for high-risk procedures and cardiogenic shock, is increasingly being combined with ECMO in creative configurations, and the literature now includes dedicated analyses of left ventricular decompression during VA-ECMO and reviews of the collision between native and device circulations. This case adds a new entry to that growing repertoire: instead of adding an Impella to unload a ventricle already supported by VA-ECMO, the team used the pump as the sole circulatory engine and paired it with purely respiratory extracorporeal support. The authors are careful to frame the approach as appropriate for selected patients, and a single case cannot establish superiority over conventional strategies. But for clinicians confronting the double failure of heart and lungs, particularly when pulmonary edema makes VA-ECMO counterproductive, the case provides a concrete, technically documented template. It suggests that thinking about circulatory and respiratory failure as separable problems, rather than as a single indication for one device, can turn a nearly certain death into a discharge home with an intact brain.

Subject of Research: Combined veno-venous ECMO and direct aortic Impella 5.5 support for emergency mitral valve replacement in acute severe mitral regurgitation with fulminant pulmonary edema

Article Title: Combined veno-venous ECMO and direct aortic impella 5.5 support enabling emergency mitral valve replacement in acute severe mitral regurgitation with fulminant pulmonary edema

Article References: Combined veno-venous ECMO and direct aortic impella 5.5 support enabling emergency mitral valve replacement in acute severe mitral regurgitation with fulminant pulmonary edema. (n.d.). https://doi.org/10.1007/s10047-026-01592-5

Image Credits: AI Generated

DOI: 10.1007/s10047-026-01592-5

Keywords: veno-venous ECMO, Impella 5.5, mechanical circulatory support, left ventricular unloading, differential hypoxemia, mitral regurgitation, pulmonary edema, cardiogenic shock, mitral valve replacement, cardiac surgery, Journal of Artificial Organs, case report