To Radiate or Not to Radiate: A Zero Fluoroscopy Approach to Emergent Bedside Atrial Septal Defect Closure Following LVAD Implantation Under Transesophageal Echocardiography
Presenter
Hamza Naveed, MBBS, HCA Houston Healthcare, Houston, TX
Hamza Naveed, MBBS, HCA Houston Healthcare, Houston, TX
Title
To Radiate or Not to Radiate: A Zero Fluoroscopy Approach to Emergent Bedside Atrial Septal Defect Closure Following LVAD Implantation Under Transesophageal Echocardiography
Introduction
Implantation of Left Ventricular Assist Device (LVAD) in the presence of a pre-existing patent foramen ovale (PFO) or iatrogenic atrial septal defect (iASD) may predispose patients to significant right-to-left shunting, resulting in critical hypoxemia. In such cases, the appropriate treatment modality has been intervention with transesophageal echocardiography (TEE)-guided ASD closure using fluoroscopy. ASD closure without fluoroscopy to reduce radiation exposure has been discussed but not properly explored[1]. Clinical Case
We present the case of a patient with a history of LVAD placement complicated by critical hypoxemia secondary to a large residual ASD shunt who was treated emergently at bedside using TEE without fluoroscopy. The 72-year-old man, with a history of severe mitral regurgitation (MR) and recent MitraClip placement, was admitted for advanced decompensated heart failure. After being placed on inotropic support, the patient underwent LVAD placement, after which he became hypoxic and was found to have a large residual ASD on TEE. Using an atrial septal occluder, the shunt was successfully closed in the absence of fluoroscopy. Although ASD closure without fluoroscopy is not well established, this case highlights a novel technique to promptly and successfully treat critical hypoxemia in patients with significant shunting. Discussion
LVAD implantation has substantial survival benefits with improved quality of life when compared with medical therapy [1]. However, postoperative complications can occur, one of which is development of worsening right to left atrial shunting, especially in patients with pre-existing patent foramen ovale or iatrogenic atrial septal defect[2]. The physiological change induced by LVAD implantation is secondary to increased unloading of the LV via the outflow cannula, thereby decreasing LA pressures [1]. This change may exacerbate shunting, causing increasing hypoxemia in patients already in a preexisting hypoxemic state [3]. Iatrogenic ASD is a known sequelae of Transcatheter Edge-to-Edge Repair (TEER) with MitraClip of the mitral valve as the procedure requires LA access through trans-septal puncture[4]. Persistent iASD after MitraClip is associated with more challenging anatomy, with a higher degree of residual MR and higher LA pressures [5]. Generally, intraoperative bubble study via surface or intracardiac echocardiography (ICE) is an important assessment to evaluate for PFO or iASD during LVAD placement [4]. In our patient’s case, shunting was refractory to primary closure likely due to extremely poor atrial septal tissue quality, requiring immediate percutaneous intervention. In our case, the patient was unstable, and due to difficulties in taking the patient to the catheterization lab, percutaneous ASD closure using TEE without fluoroscopy was performed at bedside. The concomitant use of TEE with fluoroscopic imaging generally assists in providing unique and complementary information in the ASD closure. Few reports have studied the safety of TEE-guided percutaneous ASD closure without fluoroscopy. These reports have been mostly in the setting of pediatric patients to minimize the risk of radiation[6]. This case report highlights how TEE-guided ASD closure without fluoroscopy can be performed successfully as an alternative intervention in an emergent setting.