Deadly Diarrhea: The Clever Disguise of Aortic Dissection
Aortic dissection is one of the great imitators that can present in many ways clinically, depending on the portion of the aorta undergoing dissection.1 Therefore, it is of utmost importance to discuss the variety of presentations, including those that are rare, so as not to miss this potentially fatal diagnosis. Our case is important because we believe that aortic dissection should warrant a high level of suspicion in a wide variety of patients, regardless of age, or medical or social history.
A 46-year-old gentleman with no significant past medical history presented to the Emergency Department complaining of nausea, 4-5 episodes of nonbloody, nonbilious vomiting, and 8-10 episodes of diarrhea becoming progressively bloody. His symptoms were typical for enterocolitis because they started after eating a homemade meal the night prior to admission. Initial vitals revealed the patient was hypotensive at 95/54 mm Hg (equal blood pressures bilaterally in the upper extremities), tachypneic at 30 beats per minute, oxygen saturation was 98% on room air, and there were no signs of tachycardia or fever. Laboratory assessments revealed: white blood cell count of 17.8, hemoglobin 13.5, blood urea nitrogen and creatinine of 22 and 2.0, respectively, and stool work-up was negative for Clostridium difficile. Computed tomography of the abdomen/pelvis without contrast revealed only signs of enterocolitis. Therefore, while performing an ultrasound of the right upper quadrant to rule out cholecystitis, the technician visualized a discontinuity of the distal abdominal aortic wall with a flap extending into the proximal left iliac artery, concerning for aortic dissection. Bilateral upper extremity blood pressures were repeated, showing a difference of 100 mm of mercury between the arms (legs were not evaluated). Subsequently, an immediate computed tomography angiography of the aorta performed revealed a complex aortic dissection extending from the sinuses of Valsalva to the iliac arteries, involving cervical and abdominal branches (Figure). The patient underwent immediate vascular surgical intervention via replacement of the ascending aorta by supracoronary tube graft leading to an uncomplicated postoperative course. Pathology discovered a focal, medial degeneration of the outer third of the media, leading to the aortic dissection.
Although aortic dissection tends to be more common in the elderly and those with risk factors (hypertension, coronary vascular diseases, previous cardiac interventions, and drug abuse),2 it can still present in the younger population without risk factors. Consequently, it is essential to have a high level of suspicion, even in patients not presenting with “typical symptoms” (hypertension, chest, back, and migrating pain). This rare presentation of aortic dissection similar to enterocolitis presents in < 5% of patients, indicated by nausea, vomiting, and bloody diarrhea.3 As this case demonstrates, fatal diseases such as aortic dissection can effectively imitate others, camouflaging themselves, preventing diagnosis and intervention. Thus, although patient complaints should be used to steer the medical team in the right direction, certain conditions such as aortic dissection are difficult to exclude based on presentation alone.
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-Roberto C. Swazo, MD, Bujji B. Ainapurapu, MD
This article originally appeared in the February 2017 issue of The American Journal of Medicine.