title: A randomized study on 1-week versus 4-week prophylaxis for venous thromboembolism after laparoscopic surgery for colorectal cancer.
abstract: OBJECTIVE
  To compare the efficacy and safety of antithrombotic prophylaxis given for 1 week or 4 weeks in patients undergoing laparoscopic surgery for colorectal cancer.
  
  
  BACKGROUND
  Extending antithrombotic prophylaxis beyond 1 week reduces the incidence of venous thromboembolism (VTE) after open abdominal surgery for cancer.
  
  
  METHODS
  In consecutive patients who underwent laparoscopic surgery for colorectal cancer, complete compression ultrasonography of the lower limbs was performed after 8 ± 2 days of antithrombotic prophylaxis. Patients with no evidence of VTE were randomized to short (heparin withdrawal) or to extended (heparin continued for 3 additional weeks) prophylaxis. Complete compression ultrasonography was repeated at day 28 ± 2 after surgery by investigators blinded to treatment allocation. The primary outcome of the study was the composite of symptomatic and ultrasonography-detected VTE at day 28 ± 2 after surgery.
  
  
  RESULTS
  Overall, 301 patients were evaluated for inclusion in the study and 225 were randomized. VTE occurred in 11 of 113 patients randomized to short (9.7%) and in none of the 112 patients randomized to extended heparin prophylaxis (P = 0.001). The incidence of VTE at 3 months was 9.7% and 0.9% in patients randomized to short or to extended heparin prophylaxis, respectively (relative risk reduction: 91%, 95% confidence interval: 30%-99%; P = 0.005). The rate of bleeding was similar in the 2 treatment groups. Two patients died during the study period, 1 in each treatment group.
  
  
  CONCLUSIONS
  After laparoscopic surgery for colorectal cancer, extended antithrombotic prophylaxis is safe and reduces the risk for VTE as compared with 1-week prophylaxis (NCT01589146).
authors.affiliation: *Internal and Cardiovascular Medicine-Stroke Unit, University of Perugia, Perugia, Italy †Oncology Surgery, University of Perugia, Perugia, Italy ‡General Surgery, S. Maria della Misericordia Hospital, Perugia, Italy §Unit of Angiology, University Hospital of Padua, Padua, Italy ¶General Surgery, Niguarda Hospital, Milan, Italy ‖General Surgery, S. Giovanni Battista Hospital, Foligno, Italy **Unit of Angiology, S. Giovanni Battista Hospital, Foligno, Italy ††Department of Surgical, Oncological and Gastroenterological Sciences, Section of Surgical Clinic I, University Hospital of Padua, Padua, Italy ‡‡General and Emergency Surgery, University of Perugia, Perugia, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Vedovati
authors.forename: Cecilia
authors.initials: C
authors.lastname: Becattini
authors.forename: Fabio
authors.initials: F
authors.lastname: Rondelli
authors.forename: Michela
authors.initials: M
authors.lastname: Boncompagni
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Camporese
authors.forename: Ruben
authors.initials: R
authors.lastname: Balzarotti
authors.forename: Enrico
authors.initials: E
authors.lastname: Mariani
authors.forename: Otello
authors.initials: O
authors.lastname: Flamini
authors.forename: Salvatore
authors.initials: S
authors.lastname: Pucciarelli
authors.forename: Annibale
authors.initials: A
authors.lastname: Donini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Agnelli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003082:Colectomy / Q000379:methods; D015179:Colorectal Neoplasms / Q000601:surgery*; D004334:Drug Administration Schedule; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000517:prevention & control*; D016016:Proportional Hazards Models; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D016037:Single-Blind Method; D016896:Treatment Outcome; D014463:Ultrasonography; D054556:Venous Thromboembolism / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control
chemical_list: D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight