Cardiovascular changes during multiple vertebroplasty with and without vent-hole: an experimental study in sheep

Area of Science:

• Cardiovascular research
• Surgical techniques
• Biomaterials science

Background:

• Vertebroplasty (VP) is associated with cardiovascular complications such as fat embolism (FE) and hypotension.
• Concerns exist regarding the exacerbation of these complications during multi-level VP procedures.
• Vent-holes have been proposed as a potential method to mitigate FE during VP.

Purpose of the Study:

• To investigate cardiovascular changes during multi-level VP.
• To determine if a vent-hole can prevent or reduce cardiovascular complications during VP.

Main Methods:

• An experimental study was conducted on twenty-two sheep undergoing multi-level VP with polymethylmethacrylate (PMMA) augmentation.
• Ten sheep had a vent-hole drilled in the pedicle contralateral to the injection site.
• Hemodynamic parameters (heart rate, pressures, cardiac output) and blood gas values were monitored, followed by histologic evaluation of the lungs.

Main Results:

• Consecutive augmentation of four vertebral bodies led to cumulative FE, progressively worsening mean arterial blood pressure (MABP) and blood gas values.
• The presence of a vent-hole attenuated the deterioration of MABP and blood gas values.
• Intravascular fat in the lungs was significantly reduced from 19% without a vent-hole to 9% with a vent-hole.

Conclusions:

• Multi-level VP carries risks of significant cardiovascular complications.
• A vent-hole may serve as a preventive measure by decompressing the vertebral body during cement injection.
• Clinical application of a contralateral needle for decompression during VP is suggested.