Bioaerosols during transanal minimally invasive surgery

Background: There is concern regarding bioaerosols from patients having procedures impacting surgical team safety. As pathogens and pollutants have been found in surgical smoke, we examined the potential for aerosol escape during transanal minimally invasive surgery (TAMIS) which may be particularly important given the presence of faecal contamination in the operative workspace and the specifics of its access platforms.

Methods: Both qualitative (thermographic imaging) and quantificative (particle counting) methods were used to assess for aerosol release during TAMIS in comparison to laparoscopic operations of similar duration and equipment both at times of surgical dissection and without. TAMIS was performed using a Gelport Path Device (Applied Medical) and Airseal insufflation with valveless trocar (ConMed).

Results: Significant carbon dioxide (CO₂) escapes during TAMIS carrying with it considerable numbers of particles. In general, particle counts were low prior to tissue dissection phases of the operation but increased substantially (25 × 10⁶/m³ or over 40× background counts) during hook cautery dissection. The majority of particles were in the 0.3-0.5 micron range (where counts were increased relative to background between 42× and 65) with the highest relative increase versus background in the 0.5-1.0 micron range. Particle counts < 5 were substantially greater during the TAMIS procedure versus laparoscopic procedures (a laparoscopic-assisted parastomal hernia repair and laparoscopic cholecystectomy) employing similar tools.

Conclusions: Considerable amounts of particle-rich aerosols escape during TAMIS procedures. Although pathogens are not proven to definitely spread to healthcare staff by such material nebulisation, N95/FFP2 masks, at a minimum, seem prudent while other methods evolve to eliminate this risk.