title: Prospective study of the incidence and risk factors of postsplenectomy thrombosis of the portal, mesenteric, and splenic veins.
abstract: OBJECTIVE
  Splenectomy is recognized as a cause of portal, mesenteric, and splenic vein thrombosis. The exact incidence of the complication and its predisposing factors are not known.
  
  
  METHODS
  Prospective observational cohort study. The median follow-up time of the patients was 22.6 months.
  
  
  METHODS
  University surgical clinic in a teaching hospital.
  
  
  METHODS
  A total of 147 consecutive patients who underwent splenectomy in a 4-year period were enrolled in the study.
  
  
  METHODS
  Preoperative and postoperative evaluation included ultrasonography with color Doppler flow imaging of the portal system, results of blood coagulation tests, fibrinogen levels, D-dimer levels, and complete blood counts. Operative sheets were recorded and reviewed. When portal system thrombosis (PST) was diagnosed, a complete control for acquired and congenital thrombophilia disorders was obtained.
  
  
  METHODS
  Primary end points of the study were the assessment of the incidence of postsplenectomy PST and the identification of risk factors for its occurrence.
  
  
  RESULTS
  Portal system thrombosis occurred in 7 (4.79%) of 146 patients who underwent splenectomy. The age, sex, type or length of the operation, and use of preoperative and postoperative thromboprophylaxis with low molecular weight heparin did not prove to be significant factors in the occurrence of PST. Platelet count of more than 650 x 10(3)/microL and greater spleen weight (>650 g) was associated with the development of PST (P = .01, P = .03). Normal D-dimer levels on diagnosis of the complication showed a negative predictive value of 98%. Two of the affected patients were diagnosed with thrombophilia disorders. In a median follow-up period of 22.6 months, no other case of PST was recorded.
  
  
  CONCLUSIONS
  Postsplenectomy PST occurs in approximately 5% of patients. Possible risk factors are thrombocytosis, splenomegaly, and congenital thrombophilia disorders.
authors.affiliation: First Department of Propaedeutic Surgery, Hippocration Hospital, Athens, Greece. cstamou@hotmail.com
authors.forename: Konstantinos M
authors.initials: KM
authors.lastname: Stamou
authors.forename: Konstantinos G
authors.initials: KG
authors.lastname: Toutouzas
authors.forename: Panagiotis B
authors.initials: PB
authors.lastname: Kekis
authors.forename: Socrates
authors.initials: S
authors.lastname: Nakos
authors.forename: Anthippi
authors.initials: A
authors.lastname: Gafou
authors.forename: Andreas
authors.initials: A
authors.lastname: Manouras
authors.forename: Eustathios
authors.initials: E
authors.lastname: Krespis
authors.forename: Stylianos
authors.initials: S
authors.lastname: Katsaragakis
authors.forename: John
authors.initials: J
authors.lastname: Bramis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008642:Mesenteric Veins; D008875:Middle Aged; D011169:Portal Vein; D011183:Postoperative Complications; D011446:Prospective Studies; D012307:Risk Factors; D013156:Splenectomy / Q000009:adverse effects*; D013162:Splenic Vein; D013922:Thrombocytosis / Q000097:blood / Q000150:complications; D019851:Thrombophilia / Q000097:blood / Q000150:complications / Q000151:congenital; D020246:Venous Thrombosis / Q000097:blood / Q000453:epidemiology* / Q000209:etiology
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D