Mysterious Lower GI Bleed Due to Splenic Artery-Colonic Fistula; Rare Case Report and Review of Literature

Introduction: Splenic artery aneurysm can be a result of portal hypertension which can invade localsurrounding structure leading to complications such as splenic artery-colonic fistula. Splenic artery-colonic fistulizations is an exceedingly rare phenomenon that can result in a massive GI bleed that is extremely fatal if not diagnosed accurately and promptly. Our case report explains the importance of broader differential diagnosis for patients presenting with hematochezia as well the importance of detailed medical history. Only six cases were reported in the past with similar presentations in English literature (Table 1). Case Description/Methods: 41-year-old man with past medical history of alcohol use disorder and esophageal varicespresenting for four episodes of hematochezia followed by a syncopal episode. Patient also reported 50 lb of unintentional weight loss. Patient denies any active alcohol intake with the last drink 14 months ago. Colonoscopy was noted for specks of blood in sigmoid, large amounts of blood and blood clots in cecum, ascending colon, transverse colon, descending colon. Due to the large amount of blood and poor visualization, the bleeding source in the transverse colon could not be identified. CTA revealed a splenic artery pseudoaneurysm with the splenic artery eroding into the colon causing a splenic artery-colonic fistula. Patient was resuscitated and underwent successful coil embolization of the splenic artery with no complications. Patient made a full recovery with no further complications to date. Discussion: SAA are the third most common intra-abdominal aneurysm, a major complication of whichbeing the invasion of into local anatomy. Risk factors for the development of SAA include portal hypertension, chronic pancreatitis, connective tissue disorders, and pregnancy. Diagnosing SAA can be done by utilizing a tagged red blood cell (RBC) scan, computed tomography angiography (CTA) or catheter directed angiography. Treatment of SAA is by coil embolization through directed angiography or surgical intervention. SAA should be suspected in patients who present with hematochezia who continue to have overt GI bleeding after a negative EGD and colonoscopy evaluation. Table 1. - Case reports of splenic artery-colonic fistulization reported in English literature Authors Year Age Sex Diagnostic modality EGD/Colonoscopy Surgery Treatment Current 2022 41 M CTA Colonoscopy No Angiographic Embolization Maharaj et al.1 2018 24 F Exploratory laparotomy N Yes Exploratory laparotomy O’Brien et al.2 2016 88 F CTA EGD only No Angiographic embolization Sweetser et al.3 2008 79 M CTA EGD & colonoscopy No Angiographic embolization El et al.4 2003 62 M Red cell scan N Yes Angiographic embolization Hong et al.5 1992 40 M Exploratory laparotomy EGD & sigmoidoscopy Yes Exploratory laparotomy Walker et al.6 1988 U U CTA EGD U U