title: The physiologic and pathologic effects of the reamer irrigator aspirator on fat embolism outcome:  an animal study.
abstract: OBJECTIVE
  Intramedullary reaming of long bones before nail insertion has been known to cause an increase in fat emboli introduction into the bloodstream, which is a potentially fatal phenomenon. The goal of this study was to assess whether the reamer irrigator aspirator (RIA) reamer can reduce fat embolic load compared with the standard AO reamer.
  
  
  METHODS
  Fifteen pigs were prepared using an intravenous catheter inserted into the marginal ear vein for fluid balance and drug administration. One third of the pig's blood volume was withdrawn to simulate hemorrhagic shock. Each animal underwent bilateral retrograde femoral reaming, cementing, and nailing using either an RIA or AO reamer. Assignment of a reamer type to the left or right side was done randomly and allowed for direct comparison of matching femur results. Outcome measures were obtained, namely, pulmonary arterial pressure, mean arterial pressure, partial pressure of arterial oxygen, and cardiac output. Staining techniques were used to ascertain fat emboli counts from lung tissue samples.
  
  
  RESULTS
  For mean arterial pressure, partial pressure of arterial oxygen, and cardiac output after cement injection, the RIA reamer group showed statistically higher values than the AO reamer group. In corollary, the RIA showed statistically lower pulmonary arterial pressure levels. No differences were noted at baseline, during hypovolemia, and post resuscitation. With the Student t test, no statistical differences were found between reamers regarding fat emboli counts for both staining methods. With the Mann-Whitney test, the RIA reamer showed statistically fewer emboli (7.0 versus 74.5) (P = 0.02, Z = 2.33) using Oil Red "O" staining.
  
  
  CONCLUSIONS
  The RIA reamer demonstrated superior results with respect to physiologic measures and fat emboli counts and may provide optimal results compared with the AO reamer.
authors.affiliation: Sports Medicine and Arthroscopic Shoulder & Knee Surgery, Pinnacle Health Sciences Center, Richmond Hill, Ontario, Canada.
authors.forename: Robert Y
authors.initials: RY
authors.lastname: Wang
authors.forename: Ru
authors.initials: R
authors.lastname: Li
authors.forename: Rad
authors.initials: R
authors.lastname: Zdero
authors.forename: David
authors.initials: D
authors.lastname: Bell
authors.forename: Michael
authors.initials: M
authors.lastname: Blankstein
authors.forename: Emil H
authors.initials: EH
authors.lastname: Schemitsch
mesh_terms: D000818:Animals; D001843:Bone Cements; D001858:Bone Nails; D004195:Disease Models, Animal; D004620:Embolism, Fat / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D005260:Female; D005269:Femur / Q000503:physiopathology / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation*; D013396:Suction / Q000295:instrumentation; D013552:Swine; D007507:Therapeutic Irrigation / Q000295:instrumentation
chemical_list: D001843:Bone Cements