Fluoroscopy-free Impella repositioning after coronary artery bypass grafting: case report of a novel echocardiographic-guided technique

Introduction

Cardiogenic shock (CS) complicates 5–10% of myocardial infarction cases and represents a critical condition requiring prompt intervention (1-3). Temporary mechanical circulatory support (MCS) has become a cornerstone in its management, stabilizing patients by enhancing end-organ perfusion and providing time for either cardiac recovery or the implementation of long-term interventions. Among the available options, the Impella CP is a microaxial continuous-flow pump engineered to extract blood from the ventricular cavity and eject it into the ascending aorta, thereby providing hemodynamic stabilization by delivering up to 4.3 L/min of cardiac output (4). However, its utilization may also be associated with an elevated risk of adverse events, including major bleeding complications, stroke, and all-cause mortality (5-7). Moreover, traditional repositioning techniques rely on fluoroscopic guidance, which may not be feasible in certain intraoperative settings, since transferring critically ill patients to facilities equipped with fluoroscopy presents logistical challenges that can complicate their care. This case report describes a transesophageal echocardiography (TEE)-guided approach for fluoroscopy-free Impella repositioning following coronary artery bypass grafting (CABG) and mitral annuloplasty under cardiopulmonary bypass (CPB) in a patient with severe left ventricular dysfunction. We present this case report in accordance with the CARE reporting checklist (available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-35/rc).

Case presentation

A 55-year-old male with a history of type II diabetes mellitus and dyslipidemia, but no significant prior cardiovascular events, presented to the emergency department with severe retrosternal chest pain radiating to the neck. This episode occurred upon awakening and was preceded by a one-month history of progressive exertional dyspnea and intermittent retrosternal and jugular constriction, which had worsened over the past week.

The presenting electrocardiogram is shown in Figure 1. Transthoracic echocardiography demonstrated a severely reduced left ventricular ejection fraction of 20%, with akinesia of the apex, interventricular septum, and anterior wall, as well as hypokinesia in the remaining segments. Additionally, severe predominantly functional mitral regurgitation was noted. Chest X-ray findings were consistent with pulmonary congestion.

Figure 1 Electrocardiogram at presentation.

Coronary angiography revealed severe three-vessel disease with a high SYNTAX score. The patient was admitted to the intensive care unit and placed on intra-aortic balloon pump (IABP) support as a bridge to decision-making for further intervention. A Swan-Ganz catheter was inserted into the pulmonary artery for invasive hemodynamic monitoring.

Due to low cardiac output and inadequate left ventricular venting, as demonstrated by invasive hemodynamics parameters (Table 1) and clinical signs of organ hypoperfusion with lactate levels >2 mmol/L, oliguria, and elevated liver enzymes, bilirubin, and creatinine, escalation to MCS was initiated: the IABP was removed, and an Impella CP was implanted, providing support at a flow rate of 3.8 L/min.

In the following days, there was a normalization of hemodynamic parameters (Table 1), with pulmonary arterial wedge pressure (PAWP) <15 mmHg, cardiac power output (CPO) >1 W, pulmonary artery pressure (PAP) of 40/20 mmHg, Cardiac Index (CI) of 4.5 L/min, and improved organ function, with lactate levels decreasing to <2 mmol/L, a reduction in liver enzymes, bilirubin, and creatinine, and adequate urine output.

After a cycle of levosimendan, following a multidisciplinary discussion, a surgical approach was deemed the most appropriate strategy to manage the severe and diffuse coronary artery disease and the concomitant severe mitral regurgitation: the patient underwent CABG with five grafts—left internal mammary artery to the left anterior descending artery, right internal mammary artery to the obtuse marginal branch, and sequential saphenous vein grafts to the posterior descending artery, first diagonal branch, and intermediate branch- and a mitral valve repair was also performed, with the implantation of a 30-mm Sovering™ mitral ring. The procedures were carried out under hypothermic CPB.

Over the first 48 hours following CABG and mitral anuloplasty, the patient maintained stable hemodynamic parameters (Table 1). Lactate levels remained normalized at <2 mmol/L, and renal function was preserved, as evidenced by stable creatinine levels and adequate urine output. No arrhythmias or device-related complications were observed. The patient remained hemodynamically and clinically stable until discharge.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for the publication of this case report, accompanying images and videos. A copy of the written consent is available for review by the editorial office of this journal.

Impella repositioning technique

At the beginning of the procedure, the Impella device was maintained in place to ensure hemodynamic stability during induction of anesthesia and vessel isolation, both of which could be characterized by hemodynamic instability in the presence of left ventricular dysfunction.

Before initiating CPB, the Impella device was positioned in the descending aorta to allow for the clamping of the ascending aorta at a flow rate of 0.3 L/min, preventing possible thrombosis of the circuit (Figure 2). The initial positioning of the device from the transaortic position to the descending aorta was conducted entirely under TEE guidance: the device was carefully positioned in the proximal portion of the descending aorta, within the limits of TEE visualization. This precaution also ensured the possibility of post-operative repositioning, in order to provide timely MCS in case of persistent ventricular dysfunction and hemodynamic instability.

Figure 2 Impella device positioned in the descending aorta: (A) long-axis view and (B) short-axis view obtained from the mid-esophageal descending aortic view using transesophageal echocardiography.

CABG and mitral annuloplasty were performed via a median sternotomy. At the end of the procedures, CPB was maintained to manage the blood flow, reducing it during Impella advancement to minimize resistance caused by the antegrade blood flow in the aorta.

Subsequently, CPB was discontinued, and the Impella was advanced to the aortic bulb as the first step in the repositioning process. During the repositioning of the device back to the transaortic position, the TEE probe tracked the movement of the distal portion of the Impella continuously as it advanced from the descending aorta, through the aortic arch and ascending aorta, up to the aortic valve. However, the pigtail of the Impella tended to enter the coronary sinuses, specifically resting in the non-coronary sinus (Video 1). To allow the device’s passage into the left ventricle (LV), the cardiac surgeon applied gentle manual pressure over the region of the coronary sinus where the Impella’s pigtail catheter rested, guiding it centrally through the aortic valve (Video 2). This maneuver, performed with precision and guided by TEE, enabled a controlled and atraumatic transition of the Impella into the left ventricular cavity (Video 3).

Further optimization of device positioning, once the ventricular cavity was accessed, was achieved through continuous echocardiographic guidance, providing immediate postoperative hemodynamic support without the need for fluoroscopy (Figure 3, Video 4). Importantly, TEE confirmed the absence of structural damage to the aortic valve apparatus and ruled out iatrogenic aortic regurgitation.

Figure 3 Final correct positioning of the device in the left ventricular cavity.

Discussion

This case report described the successful intraoperative repositioning of an Impella percutaneous ventricular assist device using TEE as the sole imaging modality, without the need for fluoroscopic guidance. This approach was applied as part of a planned intervention in the post-CABG setting to ensure immediate hemodynamic support during the transition from CPB.

This technique offers several potential benefits. By avoiding the need for fluoroscopic guidance and for the insertion of a brand-new Impella device, which would otherwise have to be inserted in a standard fashion, it can reduce both procedural costs and radiation exposure for the patient and medical staff. Furthermore, by eliminating the need for a new arterial access at a new site, this technique has the potential to reduce the risk of access site complications, including bleeding, arterial injury, and associated access-related morbidities (8). Finally, in patients with more severe hemodynamic instability, this technique allows for the immediate placement of an Impella device without the need for subsequent removal and/or reinsertion, thereby providing enhanced MCS during the critical bridge-to-decision period while awaiting potential surgical intervention. The limitations of this technique include several factors. First, the absence of fluoroscopic guidance introduces technical challenges, such as a higher potential for device malposition or incomplete traversal of the aortic valve, which could compromise procedural success. Second, there is a risk of vascular injury during advancement, particularly in the absence of a guidewire, which requires precise manipulation under TEE visualization to mitigate. Finally, the technique carries a theoretical risk of embolic events, especially in patients with significant atherosclerosis or thrombus burden.

In relation to our experience, previous studies explored alternative techniques for Impella repositioning in specific clinical contexts. Masiello et al. (9) reported the successful bedside repositioning of an Impella 5.0 device using TEE and rapid ventricular pacing to traverse the aortic valve without fluoroscopy. However, our method was part of a planned intraoperative strategy specifically designed to ensure hemodynamic stability post-CABG and CPB, while Masiello et al. described a technique performed to address accidental device dislodgement. Other studies, such as those by Dembo et al. (10) and Alaiti et al. (11), highlight fluoroscopy-dependent methods like snare-guided repositioning, which are effective but fluoroscopy-guided and less applicable in intraoperative settings.

The standard, fluoroscopy-guided method for Impella positioning involves advancing a diagnostic pigtail catheter over a 0.035-inch J-tip guidewire across the aortic valve into the LV, followed by the introduction of a 0.018-inch guidewire into the LV. The Impella device is then advanced over the 0.018-inch guidewire into its final transaortic position, ensuring accurate placement for effective hemodynamic support.

Advancing the Impella blindly across the valve without the structural support of a guidewire can result in significant mechanical complications. The aortic valve cusps impose resistance that may cause the distal portion of the cannula to buckle, leading to kinking. Such deformation compromises device functionality, impairing the precise positioning required for effective hemodynamic support. Additionally, kinking increases the risk of damaging the valve leaflets or inducing trauma to the left ventricular outflow tract.

Another critical challenge arises from the tendency of the Impella pigtail to lodge within the coronary sinuses when guidewire support is absent. This misalignment not only prevents the catheter from prolapsing naturally across the valve, as is achievable with diagnostic catheters, but also significantly increases the risk of kinking if forward pressure is applied. A kinked Impella cannula poses additional complications, including potential difficulty in retrieval through the arterial introducer sheath, further exacerbating procedural challenges and risks. Following CABG performed with CPB, patients with severe left ventricular dysfunction require immediate hemodynamic support to ensure a safe transition from extracorporeal circulation. The logistical challenges of transferring critically ill patients to fluoroscopy-equipped facilities further complicate their management. Our strategy overcomes these limitations by allowing the procedure to be performed directly in the cardiac surgery operating room, eliminating the need for fluoroscopic guidance. This approach was made possible by the median sternotomy, which allowed for manual pressure to be applied to the coronary sinus, while the retrograde advancement of the Impella into the aorta was facilitated by the low antegrade flow maintained by the ongoing extracorporeal circulation. However, we acknowledge that this method was demonstrated in a single case with in-hospital outcomes, limiting its generalizability. Larger studies are required to validate its reproducibility, safety, and efficacy across broader clinical settings and patient populations.

Conclusions

This case demonstrates the feasibility and safety of repositioning an Impella device intraoperatively using TEE without fluoroscopic guidance, providing rapid hemodynamic support in intraoperative settings.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-35/rc

Peer Review File: Available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-35/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-35/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for the publication of this case report, accompanying images and videos. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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