Pressurization of vertebral bodies during vertebroplasty causes cardiovascular complications: an experimental study in sheep.
METHODS
An experimental study of cardiovascular complications arising during vertebroplasty (VP) of multiple levels in sheep.


OBJECTIVE
To investigate the effect of pressurizing vertebral bodies during VP using different materials in the development of fat embolism (FE) and any associated cardiovascular changes.


BACKGROUND
Polymethylmethacrylate (PMMA) is the material of choice for VP. However, PMMA has several disadvantages, such as toxicity, exothermic curing, uncertain long-term biomechanical effects, and biocompatibility. Alternative materials are being developed for VP; however, there is the concern that an increase in intraosseous pressure and displacement of bone marrow contents could lead to FE and hypotension during VP regardless of what type of materials is used.


METHODS
In 20 sheep, four vertebral bodies were augmented either with PMMA or bone wax. Heart rate; arterial, central venous, and pulmonary artery pressure; cardiac output; and blood gas values were recorded. Postmortem the lungs were subjected to histologic evaluation.


RESULTS
The consecutive augmentation of four vertebral bodies with PMMA induced a cumulative FE that gradually deteriorated baseline mean arterial blood pressure (MABP) and blood gas values. The augmentation with bone wax resulted in similar cardiovascular changes and amount of intravascular fat in the lungs.


CONCLUSIONS
There are potential cardiovascular complications during VP of multiple levels regardless of the augmentation material used. The deteriorating baseline MABP during VP is associated with the pressurization of the vertebral bodies rather than with the use of polymethylmethacrylate.
Aebli
Nikolaus
N
Department of Orthopaedic Surgery, Medical School, University of Otago, Dunedin, New Zealand.
Krebs
Jörg
J
Schwenke
Daryl
D
Davis
Gerard
G
Theis
Jean-Claude
JC
D000818:Animals; D001696:Biomechanical Phenomena; D001794:Blood Pressure / Q000187:drug effects; D001843:Bone Cements / Q000494:pharmacology / Q000633:toxicity; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D002496:Central Venous Pressure / Q000187:drug effects; D004338:Drug Combinations; D004620:Embolism, Fat / Q000139:chemically induced / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D007431:Intraoperative Complications / Q000139:chemically induced / Q000503:physiopathology; D008168:Lung / Q000098:blood supply / Q000473:pathology; D019637:Orthopedic Procedures / Q000379:methods*; D010100:Oxygen / Q000097:blood; D010168:Palmitates / Q000494:pharmacology / Q000633:toxicity; D019904:Polymethyl Methacrylate / Q000494:pharmacology / Q000633:toxicity; D011651:Pulmonary Artery / Q000187:drug effects / Q000503:physiopathology; D012756:Sheep; D013131:Spine / Q000187:drug effects / Q000503:physiopathology / Q000601:surgery*; D014885:Waxes / Q000494:pharmacology / Q000633:toxicity
D001843:Bone Cements; D004338:Drug Combinations; D010168:Palmitates; D014885:Waxes; D002245:Carbon Dioxide; C055480:bone wax; D019904:Polymethyl Methacrylate; D010100:Oxygen