title: A comparison of particulate and onyx embolization in preoperative devascularization of juvenile nasopharyngeal angiofibromas.
abstract: BACKGROUND
  Juvenile nasopharyngeal angiofibromas (JNAs) are hypervascular tumors that may benefit from preoperative devascularization to reduce intraoperative blood loss (IBL). The purpose of this study was to compare transarterial particulate embolization (TAPE) with the direct percutaneous embolization (DPE) technique using ethylene vinyl alcohol (Onyx, ev3, Irvine, CA) for the preoperative devascularization of a JNA.
  
  
  METHODS
  We retrospectively reviewed 50 consecutive JNA resections since 1995 for which preoperative embolization was either transarterial with particulate material (n = 39) or DPE (n = 11) using only Onyx. The IBL, transfusion requirements, operative time, and length of hospital admission were compared between the two groups.
  
  
  RESULTS
  The mean IBL was 1,348.7 ± 932.2 mL particulate group, 569.1 ± 700.7 mL Onyx group (one-tailed Student's t test p = 0.003). The mean unit of packed red blood cells was 1.56 ± 2.01 units particulate group, 0.45 ± 1.04 units Onyx group (p = 0.009). The relationship between embolization type and IBL remained significant or strongly correlated when accounting for the Fisch stage of the tumor (p = 0.010 and p = 0.056, respectively, by a multivariate least squares fit; alternately p = 0.0003 and p = 0.023, respectively, in the subset of patients with Fisch stage III tumors only). We also found that the proportion of resections for which an endoscopic approach could be used was significantly higher in the Onyx group than the particulate group (81.8 and 18.2 %; Pearson p = 0.0002), and this was also significant both in our multivariate nominal logistic fit (p < 0.001) and in the subset of patients with Fisch stage III tumors (p = 0.018).
  
  
  CONCLUSIONS
  Pre-operative DPE with Onyx of a JNA when compared to TAPE significantly decreased IBL and RBC transfusion requirement during surgical resection. The proportion of surgical resections performed from an endoscopic approach was higher in the DPE Onyx group, which may have affected the results.
authors.affiliation: Medical School, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Gao
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Gemmete
authors.forename: Neeraj
authors.initials: N
authors.lastname: Chaudhary
authors.forename: Aditya S
authors.initials: AS
authors.lastname: Pandey
authors.forename: Steven E
authors.initials: SE
authors.lastname: Sullivan
authors.forename: Erin L
authors.initials: EL
authors.lastname: McKean
authors.forename: Lawerence J
authors.initials: LJ
authors.lastname: Marentette
mesh_terms: D000293:Adolescent; D018322:Angiofibroma / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D016461:Chemoembolization, Therapeutic / Q000379:methods*; D004121:Dimethyl Sulfoxide / Q000627:therapeutic use*; D005260:Female; D006490:Hemostatics / Q000627:therapeutic use; D006801:Humans; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D009389:Neovascularization, Pathologic / Q000209:etiology / Q000628:therapy*; D052638:Particulate Matter / Q000627:therapeutic use*; D011145:Polyvinyls / Q000627:therapeutic use*; D011300:Preoperative Care / Q000379:methods; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D006490:Hemostatics; C450660:Onyx copolymer; D052638:Particulate Matter; D011145:Polyvinyls; D004121:Dimethyl Sulfoxide