S6176 Chronic Mesenteric Ischemia Due To Endoleak Causing Internal Hernia and Small Bowel Obstruction Following Thoracic Endovascular Aorta Repair (TEVAR)

Introduction: Chronic mesenteric ischemia (CMI) is a rare but serious condition resulting from prolonged mesenteric hypoperfusion, often related to atherosclerosis or prior vascular interventions. Endoleaks following thoracic endovascular aortic repair (TEVAR) can lead to chronic mesenteric ischemia over time, potentially causing severe gastrointestinal complications. Case Description/Methods: We present the case of an 86-year-old man with a history of type B thoracic aortic dissection treated with TEVAR and left renal artery stenting, who presented 1 year later with new-onset epigastric pain and signs of bowel obstruction. A chronic endoleak had been identified 6 months post-TEVAR. Computed tomography imaging revealed a chronic, stable endoleak and findings suggestive of an internal hernia with partial small bowel obstruction. Exploratory laparotomy confirmed a closed-loop obstruction secondary to an internal hernia through a peritoneal defect, necessitating small bowel resection and re-anastomosis. Remarkably, the patient did not exhibit typical metabolic features of acute mesenteric ischemia, such as lactic acidosis, and remained hemodynamically stable, consistent with a chronic ischemic process. His postoperative course was complicated by transient bradyarrhythmia and melena, though no active bleeding source was identified on endoscopy or imaging. He was discharged to acute rehabilitation with stable hemoglobin but unfortunately passed away during his rehab stay. Discussion: This case illustrates an atypical and delayed gastrointestinal complication of TEVAR-associated endoleak. Chronic mesenteric ischemia may develop insidiously, particularly in elderly patients with persistent endoleaks, and can progress to serious complications such as internal herniation and small bowel obstruction—even in the absence of acute ischemic markers. Stable endoleaks can obscure evolving ischemic injury, emphasizing the need for long-term vigilance and surveillance in post-TEVAR patients. Clinicians should maintain a high index of suspicion for chronic mesenteric ischemia and its complications in patients with a history of aortic interventions. Early recognition and multidisciplinary management are crucial to preventing life-threatening outcomes.