title: Portomesenteric venous thrombosis associated with rectal venous malformations.
abstract: OBJECTIVE
  We report thrombosis of portal and mesenteric veins in patients with a pattern of rectal venous malformations (VMs) and ectatic major mesenteric veins.
  
  
  METHODS
  Eight patients having rectal VMs with either ectatic mesenteric veins and/or evidence of portomesenteric venous thrombosis (PVT), evaluated from 1995-2009, were reviewed.
  
  
  RESULTS
  Portomesenteric venous thrombosis was evident in 5 patients at presentation. Three had patent ectatic mesenteric veins, 2 with demonstrated reversal of flow, and 2 of whom went on to thrombosis during observation. Six patients developed portal hypertension. Five remain on long-term anticoagulation. After recognizing this pattern, one patient underwent preemptive proximal ligation of the inferior mesenteric vein (IMV) to enhance antegrade portal vein flow and prevent propagation or embolization of venous thrombus from the IMV to the portal vein.
  
  
  CONCLUSIONS
  Rectal VMs should be evaluated for associated ectatic mesenteric veins. The ectatic vein siphons flow from the portal vein down to the rectal VM, leading to stagnation of blood in the portal vein and resultant thrombosis. Primary thrombosis in the stagnant rectal VM and/or mesenteric vein can also predispose to embolization up into the portal vein. This pattern of rectal VM and ectatic mesenteric vein should be considered a risk factor for devastating PVT.
authors.affiliation: Department of Surgery, Children's Hospital Boston, Boston, MA 02115, USA.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Kulungowski
authors.forename: Victor L
authors.initials: VL
authors.lastname: Fox
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Burrows
authors.forename: Ahmad I
authors.initials: AI
authors.lastname: Alomari
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Fishman
mesh_terms: D000293:Adolescent; D000328:Adult; D000925:Anticoagulants / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008026:Ligation / Q000379:methods; D008297:Male; D008642:Mesenteric Veins; D010690:Phlebography; D011169:Portal Vein; D012007:Rectum / Q000098:blood supply*; D016896:Treatment Outcome; D054079:Vascular Malformations / Q000150:complications* / Q000175:diagnosis; D020246:Venous Thrombosis / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D055815:Young Adult
chemical_list: D000925:Anticoagulants