title: Incidence of deep vein thrombosis after colorectal surgery in a Chinese population.
abstract: BACKGROUND
  Contemporary studies indicate that the incidence of deep vein thrombosis (DVT) is increasing in the Asian population. The present study aims to evaluate the incidence of postoperative DVT in Chinese patients undergoing surgery for colorectal malignancies.
  
  
  METHODS
  Fifty-one consecutive patients with carcinoma of the rectum or sigmoid colon scheduled for resection were included in the study. None of the study subjects were given any form of DVT prophylaxis. Serial duplex ultrasound of both lower limbs were examined in the preoperative and postoperative periods.
  
  
  RESULTS
  Three patients were excluded from the study because of the presence of DVT noted preoperatively. A total of 20/48 (41.7%) patients developed asymptomatic calf vein thrombosis. One out of 20 patients required anticoagulation because of thrombus propagation. None of the subjects showed signs or symptoms of DVT or pulmonary embolism. A total of 7/20 thrombi resolved completely at 4 weeks after operation. Only old age and smoking were identified as being associated with a higher incidence of DVT. Disseminated disease, type of operation, duration of operation and postoperative complications did not appear to be risk factors for DVT.
  
  
  CONCLUSIONS
  A high incidence of asymptomatic calf vein thrombosis occurred after colorectal surgery for malignancies in Chinese. The majority did not progress even without anticoagulation.
authors.affiliation: Department of Surgery and Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: F Y
authors.initials: FY
authors.lastname: Lee
authors.forename: W
authors.initials: W
authors.lastname: Chu
authors.forename: R
authors.initials: R
authors.lastname: Chan
authors.forename: Y F
authors.initials: YF
authors.lastname: Leung
authors.forename: K H
authors.initials: KH
authors.lastname: Liu
authors.forename: S M
authors.initials: SM
authors.lastname: Ng
authors.forename: P B
authors.initials: PB
authors.lastname: Lai
authors.forename: C
authors.initials: C
authors.lastname: Metreweli
authors.forename: W Y
authors.initials: WY
authors.lastname: Lau
mesh_terms: D000367:Age Factors; D015179:Colorectal Neoplasms / Q000601:surgery*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000453:epidemiology*