When the HeRO Becomes the Villain

Abstract

A 28-year-old woman with ESRD due to hypertension presented to the emergency room with a 2-day history of pain and swelling on the left side of her neck and jaw. She denied any inciting factors prior to symptoms, but relayed that her dialysis treatment could not be performed through her left-sided upper arm Hemodialysis Reliable Outflow (HeRO) (Merit Medical Systems, Inc., South Jordan, UT, USA) graft the prior day as it had appeared to have clotted.On physical examination the patient had a markedly edematous left neck with a large tender palpable mass. Her vital signs were normal, no bruit or thrill was appreciated over her AVG site, and no other obvious findings were appreciated. A computed tomography (CT) scan of the neck revealed a large hematoma within the left sternocleidomastoid muscle (Figure 1). Concerns about the integrity of the HeRO graft prompted a chest radiograph (CXR), which was compared to previous imaging collected 1 month earlier (Figures 2A-1 month ago, and 2B-present). Questions?1) What do the chest radiographs demonstrate?2) What is the optimal management at this time? Answers: 1) The venous outflow component of the HeRO graft had uncoupled and migrated into the superior vena cava, with the end of the uncoupled component of the catheter terminating in the right ventricle. The hematoma was due to the disconnection of the arterial inflow component and the venous outflow component, allowing blood to pool in the subcutaneous space. HeRO grafts are rigid wire mesh supported grafts that when placed through a stenotic segment of a central vein improves the lumen size and patency of that vein. The venous outflow portion of the HeRO terminates in or near the right atrium while the arterial inflow component is a standard AV graft. The two components are held together by a connector (Figure 3). This provides adequate flow so that the normal arterial inflow portion of the AV graft can be cannulated for hemodialysis not unlike any standard AV graft. Complications associated with HeRO grafts include right atrial clots and pulmonary emboli, 1,2 infection, 2 and gastrointestinal bleeding from downstream esophageal varices. 3 This is the first case we are aware of reporting an uncoupling of HeRO graft components. Fortunately the bleeding was confined and limited by the subcutaneous space to prevent continued hemorrhage. 2) The patient was placed on continuous cardiac monitoring to evaluate for arrhythmias. Interventional Radiology was consulted with successful HeRO graft retrieval and placement of a new tunneled HD access catheter. F I G U R E 1 Computed tomography (CT) revealing a large hematoma within the left sternocleidomastoid muscle (arrow)