Mediastinal Abscess: An Uncommon Cause Of Dysphagia

SESSION TITLE: Medical Student/Resident Cardiothoracic Surgery Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Endograft infection and abscess formation is a rare late complication of endovascular aortic aneurysm repair (EVAR) with an estimated incidence 0.05-4% [1]. Fever and weight loss are the most common presenting complaints secondary to systemic inflammatory response. Less frequently extension of the infection to adjacent structures such as the esophagus, left main bronchus, left atrium or vertebrae causes symptoms related to their compromised function. We report a patient with extrinsic dysphagia resulting from a mediastinal abscess complicating EVAR. CASE PRESENTATION: A 78-year-old female presented with a 16-day history of worsening dysphagia (solids and liquids) and upper back pain. Past history included a thoracic EVAR two years prior which was complicated by vertebral osteomyelitis successfully treated with intravenous antibiotics. On exam, afebrile, hemodynamically stable without any focal abnormalities. Initial labs were significant for a microcytic anemia and malnourishment suggestive of chronic inflammation. Blood cultures were obtained and negative. A computed tomography (CT) chest scan demonstrated 3.5 cm, ill-defined hypodensity along the anteromedial aspect of the thoracic aorta which was inseparable from the thoracic esophagus [Figure 1A]. Due to worsening dysphagia, an esophagram was ordered which revealed an anterior luminal filling defect of the esophagus [Figure 1B]. Esophagogastroduodenoscpy showed extrinsic compression along the length of the esophagus. During the admission, she developed worsening leukocytosis and was started on vancomycin and meropenem for empiric antibiotic coverage. A repeat CT chest demonstrated an enlarging complex loculated abscess in the posterior mediastinum, which extended around the thoracic aorta graft, thoracic vertebrae and compressed the esophageal lumen [Figure 2A-B]. Thoracic surgery consultation was obtained and given the patient’s age and complexity of the procedure; she was deemed a high-risk surgical candidate. Ultimately the patient decided to pursue comfort care and was discharged on hospice. DISCUSSION: The differential diagnosis of dysphagia can be divided into intrinsic and extrinsic etiologies [2]. Extrinsic causes include abscesses, thyroid masses, lung cancer, metastatic adenopathy, aortic aneurysm, dissection, or cardiomegaly. Clinicians should consider possible mediastinal abscess in patients with dysphagia and a history of EVAR as it is associated with a high mortality rate. One multicenter study observed a 30-day mortality rate of 38.4% and overall mortality of 50% in 26 cases [3]. In the study all infected grafts required open graft explantation and surgical revision. CONCLUSIONS: Mediastinal abscess is an uncommon extrinsic cause of dysphagia and rare complication following thoracic EVAR. Early recognition, broad empiric antibiotics, and early surgical intervention with graft explantation are the cornerstones of management. Reference #1: Hobbs SD, Kumar S., and Gilling-Simth GL. Epidemiology and diagnosis of endograft infection. The Journal of Cardiovascular Surgery. 2010 February; 51(1):5-14 Reference #2: Carucci LR, Turner MA. Dysphagia revisited: common and unusual causes. Radiographics. 2015 Jan-Feb;35(1):105-22. doi: 10.1148/rg.351130150. Reference #3: Capoccia L, Speziale F, Menna D et al. Preliminary results from a national enquiry of infection in abdominal aortic endovascular repair. Annals of vascular surgery. 2016 (30) 198-204. DISCLOSURES: No relevant relationships by Tamar Gubeladze, source=Web Response No relevant relationships by Zachary Holliday, source=Web Response No relevant relationships by Michael Nance, source=Web Response No relevant relationships by Tarang Patel, source=Web Response