title: Anticoagulation risk in spine surgery.
abstract: METHODS
  Systematic review.
  
  
  OBJECTIVE
  To determine the high-risk populations for thromboembolic events in spine surgery patients, the risk of anticoagulation in spine surgery patients by type of anticoagulation, and whether there is a safe perioperative window of nonanticoagulation for these high-risk patients.
  
  
  BACKGROUND
  Thromboembolic complications after major spinal surgery is a significant risk for patients. Anticoagulation to reduce this risk is of concern because of the possibility of excessive bleeding or postoperative hematomas and associated neurologic deficits. There seems to be a paucity of literature on this topic.
  
  
  METHODS
  A systematic review of the English-language literature was undertaken for articles published between January 1990 and December 2008. Electronic databases and reference lists of key articles were searched to identify published studies examining coagulopathy in major spine surgery. Two independent reviewers assessed the strength of literature using the Grading of Recommendations Assessment, Development, and Evaluation criteria, assessing quality, quantity, and consistency of results. Disagreements were resolved by consensus.
  
  
  RESULTS
  A total of 93 articles were initially screened, and 29 ultimately met the predetermined inclusion criteria. The risk of thromboembolism in patients not receiving chemical prophylaxis was slightly higher in surgery to correct deformity (5.3%) and trauma patients (6.0%) than in surgery for degenerative conditions (2.3%). Fatal pulmonary embolism was rare. Bleeding complications occurred rarely with the use of anticoagulation; risk of major bleeding ranged from 0.0% to 4.3% across several types of anticoagulants. Postoperative hematoma was reported in only 10 of 2507 patients.
  
  
  CONCLUSIONS
  Venous thromboembolism is uncommon after elective spine surgery. Trauma patients are at increased risk, and chemical prophylaxis should be considered. The safe timing of the administration of anticoagulation agents is unknown.
authors.affiliation: Department of Neurosurgery, Vanderbilt University Medical Center, T-4224 Medical Center North, Nashville, TN 37232, USA. joseph.cheng@vanderbilt.edu
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Cheng
authors.forename: Paul M
authors.initials: PM
authors.lastname: Arnold
authors.forename: Paul A
authors.initials: PA
authors.lastname: Anderson
authors.forename: Dena
authors.initials: D
authors.lastname: Fischer
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Dettori
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects* / Q000592:standards / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D019106:Postoperative Hemorrhage / Q000139:chemically induced / Q000453:epidemiology* / Q000517:prevention & control; D018570:Risk Assessment; D013122:Spinal Diseases / Q000601:surgery*; D013923:Thromboembolism / Q000188:drug therapy* / Q000453:epidemiology* / Q000517:prevention & control; D014947:Wounds and Injuries / Q000150:complications
chemical_list: D000925:Anticoagulants