title: Incidence of venous thromboembolism and its pharmacological prophylaxis in Asian general surgery patients: a systematic review.
abstract: BACKGROUND
  Venous thromboembolism (VTE) is a condition that has always been perceived to be rare in Asia. The aim of this systematic review was to gather the current available evidence on the incidence of VTE in this population. A secondary aim was to assess the efficacy of pharmacological prophylaxis, and hence determine its role, in the Asian population.
  
  
  METHODS
  A comprehensive literature search was performed using MEDLINE, Embase, and the Cochrane Database of Systematic Reviews in June 2014. Articles found using search terms related to venous thromboembolism (VTE), Asian countries and general surgery procedures and pathologies were screened using the following inclusion criteria: (1) either the population studied was primarily Asian or the study was conducted in an Asian country, (2) the subjects studied underwent a major gastrointestinal or other general surgery procedure, (3) the primary outcome was the incidence of deep vein thrombosis (DVT) or pulmonary embolus (PE), and (4) secondary outcomes assessed included mortality and complications due to the VTE or prophylaxis against VTE.
  
  
  RESULTS
  Fourteen publications with a total of 11,218 patients were analyzed. Nine of the fourteen were observational studies, with half being prospective in nature. There were five interventional studies of which two were randomized controlled trials. Among the observational studies, the median (range) incidence of above-knee DVT was 0.08 % (0-2.9 %), while the median (range) incidence of PE was 0.18 % (0-0.58 %). The rates of DVT in the control groups were reported to be between 0 and 7.4 %, while the incidence of PE in the control groups ranged from 0 to 1.9 %. Analysis of the comparative studies revealed that the incidence of bleeding-related complications varied from 0 to 18.1 % in the low-molecular-weight heparin (LMWH) group compared to 0-7.5 % in the control group. The difference in minor bleeding complications between the LMWH group and the control group was found to be statistically significant.
  
  
  CONCLUSIONS
  Data from this systematic review suggest that the risk of VTE in Asian general surgery patients is low, even in the context of risk factors typically regarded as high risk.
authors.affiliation: Hepatic, Pancreatic and Biliary (HPB) Surgery Unit, Department of General Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore, dansonis@yahoo.com.
authors.forename: Danson X W
authors.initials: DX
authors.lastname: Yeo
authors.forename: Sameer
authors.initials: S
authors.lastname: Junnarkar
authors.forename: Sunder
authors.initials: S
authors.lastname: Balasubramaniam
authors.forename: Yen Pin
authors.initials: YP
authors.lastname: Tan
authors.forename: Jee Keem
authors.initials: JK
authors.lastname: Low
authors.forename: Winston
authors.initials: W
authors.lastname: Woon
authors.forename: Tony Chun Yeung
authors.initials: TC
authors.lastname: Pang
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001208:Asia; D044466:Asian People; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D011655:Pulmonary Embolism / Q000453:epidemiology* / Q000517:prevention & control*; D012307:Risk Factors; D013514:Surgical Procedures, Operative; D020246:Venous Thrombosis / Q000453:epidemiology* / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight