INTRODUCTION: An  aorto-enteric  fistula  is  a  fistulous communication  between  the  duodenum  and  the  aorta. The  non-traumatic  form,  or  primary  aorto-enteric  fistula (PAEF), is rare and fatal if untreated.  This is a case of PAEF in a Filipino patient who presented with upper gastrointestinal bleeding (UGIB).
CLINICAL PRESENTATION: A  62-year-old  Filipino  sought consult  for  hematemesis  and  melena.  He  had  just  been discharged the previous day and sent home on empiric H. pylori eradication therapy after a week of workup, which included an unremarkable esophagogastroduodenoscopy (EGD). He claimed to be hypertensive but was not taking any maintenance anti-hypertensive medication.
PHYSICAL FINDINGS: Blood  pressure  was  80/50  mmHg,and  cardiac  rate  of  94  bpm.  He  had  pale  palpebral  conjunctivae,  and  pale  nailbeds.Abdominal  exam  was  unremarkable.  Rest  of  physical  exam  was  normal.  Stat hemoglobin was 63 g/dL.
RESULTS: Exploratory  laparotomy  revealed  the  primary aortoduodenal  fistula  at  the  anterolateral  aspect  of  the fourth  segment  of  the  duodenum  (PADF).  Patient  was  started  on  metoprolol  and  atorvastatin.  Axillary  femoro-femoral  bypass,  ligation  of  aorta,  wedge  resection  of  aortoduodenal fistula, duodenorrhaphy, tube jejunostomy completed  was  done.  Post-operative  course  was  complicated by peritonitis and sepsis, and eventually went into arrest on his third week.
SIGNIFICANCE: This is the first case of PAEF in our institution,and possibly in the country. It is an extremely rare condition that has an annual incidence of 0.007 per million. Since its description in 1843, only 250 cases have been reported in literature.
RECOMMENDATIONS: A  high  index  of  suspicion  is  key  to  its diagnosis  and  management.Massive  UGIB,  a  negative  endoscopy, and known aortic aneurysm should raise the suspicion  for  PAEF,  as  prompt  surgical  intervention  is  the only chance for survival among these patients.