title: Optimal schedule of preoperative embolization for spinal metastasis surgery.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  To investigate the relationship between intraoperative blood loss during spinal metastasis surgery and the surgical delay after preoperative embolization.
  
  
  BACKGROUND
  Delaying surgery after embolization is thought to diminish its effectiveness because of revascularization, but there has been no scientific study that supports this hypothesis.
  
  
  METHODS
  We reviewed data from 66 consecutive posterior palliative decompression surgical procedures for spinal metastasis from thyroid and renal cell carcinoma (39 thyroid and 27 renal) in 58 patients between 2004 and 2012. All patients underwent preoperative angiography. The timing of preoperative embolization was determined on the basis of the operating room and interventional radiologist schedules. Excluding one case who did not receive embolization due to lack of hypervascularity, we analyzed 65 cases to compare intraoperative blood loss according to the completeness of embolization and the time lapse between embolization and surgery.
  
  
  RESULTS
  Surgical procedures were performed on the same day of embolization in 21 cases (same day-group), and on the next day after embolization in 39 cases (next-day group). Five surgical procedures were performed 2 days later. The intraoperative blood loss was significantly lesser with complete embolization than with partial embolization (mean ± standard deviation: 809 ± 835 vs. 1210 ± 904 mL, P = 0.03). Among those with complete embolization, the intraoperative blood loss as well as the perioperative transfusion requirement was significantly lesser in the same-day group than in the next-day group (mean ± standard deviation: blood loss: 433 ± 376 vs. 1012 ± 974 mL, P = 0.01; transfusion requirement: 1.5 ± 1.7 vs. 4.2 ± 4.1 units, P = 0.04).
  
  
  CONCLUSIONS
  Preoperative embolization showed greater effectiveness in reducing intraoperative blood loss when surgery for spinal metastasis was performed on the same day than when surgery was delayed. Surgery should be performed on the same day of embolization if possible.
  
  
  METHODS
  4.
authors.affiliation: Departments of *Orthopaedic Surgery and Musculoskeletal Oncology and †Radiology, Tokyo Metropolitan Komagome Hospital, Tokyo, Japan.
authors.forename: So
authors.initials: S
authors.lastname: Kato
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hozumi
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Takaki
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Yamakawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Goto
authors.forename: Taiji
authors.initials: T
authors.lastname: Kondo
mesh_terms: D000368:Aged; D016063:Blood Loss, Surgical; D001803:Blood Transfusion; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000601:surgery / Q000628:therapy; D019299:Decompression, Surgical / Q000379:methods*; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery / Q000628:therapy; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D011859:Radiography; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000556:secondary / Q000601:surgery* / Q000628:therapy*; D013131:Spine / Q000000981:diagnostic imaging / Q000601:surgery; D013964:Thyroid Neoplasms / Q000473:pathology / Q000601:surgery / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome