Oreste Gallo, MD; Luca Giovanni Locatello, MD
Department of Otorhinolaryngology,
Careggi University Hospital,
Florence - Largo Brambilla, 3 - 50134 Florence, Italy
* Corresponding author: Prof. Oreste Gallo, MD, Department of
Otorhinolaryngology, Careggi University Hospital, Florence - Largo
Brambilla, 3 - 50134 Firenze, Italy. +39 0557947989, oreste.gallo at
unifi.it
Keywords: COVID-19, laser-assisted surgery, surgical plume, prevention,
surgical safety
Authors’ contributions: Gallo: Conceptualization, supervision and
writing - review and editing; Locatello: Conceptualization, resources,
supervision, and writing - review and editing.
Conflict of Interest: all authors declare they have nothing to disclose.
This research did not receive any specific grant from funding agencies
in the public, commercial, or not-for-profit sectors.
Many of the safety issues related to the novel COVID-19 in our routine
surgical practice were thoroughly presented in this Journal. [1]
However, the authors did not discuss an important field of head and neck
surgery: laser-assisted procedures. Historically, human-papillomavirus
(HPV) in the setting of respiratory recurrent papillomatosis is the
prototype of the biological hazards of the laser-generated surgical
plume.[2] In the past, it was shown that surgical vaporization was
capable to contaminate the staff’s personal protective equipment (PPE)
with viable and infectious HPV virions. [2] Despite the growing
evidence documenting a key role of high-risk HPV infections in the
pathogenesis and development of head and neck cancer, the risk
assessment of potential viral infection after exposure to laser plume is
still controversial. [3] The biohazard might not be limited to HPV
airborne transmission, but also other bacteria and viruses, including
(possibly) SARS-CoV-2. For instance, Kwak et al. documented Hepatitis B
(HBV) DNA in surgical smoke from 10 out of 11 HBV+ patients undergoing
robotic laparoscopic surgery thus suggesting a potential risk of
airborne HBV infection.[4] Heat-generating procedures by
electrosurgical equipment or lasers can induce thermal disruption of
viable human cells and they are able to aerosolize hazardous particles.
The thermal effect of lasers on biological tissues is a complex process
resulting from the conversion of light to heat whose effects depend upon
several factors: the physical denaturation and/or destruction is a
function of laser settings (wavelength, power, time and mode of
emission, beam profile, and spot size) and the target of the procedure
(thermal parameters, optical coefficient, etc.).[5,6] During
ablative surgery, the tissue is heated by the absorbed laser energy and
it evaporates or sublimates, while, at higher power, the tissue is
typically converted to plasma. This means that during laser-tissue
interaction aerosolized blood and interstitial and intracellular fluids,
along with their possible burden of viral pathogens and hazardous
chemicals are forcefully ejected in the operating room.[6]
Nonetheless, controversies exist in the literature regarding efficient
viral infection of healthcare staff after exposure to surgical smoke.
[3,5,6]
Surgical use of different types of lasers (CO2, Nd:YAG,
KTP…) is common not only in the head and neck but also in
gynecology, dermatology, and respiratory medicine among other fields.
Even though there is a lack of conclusive data on plume-borne
contamination, there is an urgent need to raise awareness of its risks
during the COVID-19 pandemic. In the next years, our daily practice of
transoral laser-assisted surgery, an incontournable strategy to treat
several benign and malignant lesions of the upper aerodigestive tract
with excellent oncological and functional results, is going to be deeply
modified. High viral loads, especially in the nose and the pharynx, can
be detected after symptom onset but general consensus exists on
SARS-CoV-2 diffusion by droplet transmission even from asymptomatic
individuals, therefore it is conceivable that every laser procedure is
to be considered as high-risk.[7]
While waiting for more robust specific evidence, we would like to recall
some precautionary measures, inspired by the most recent
literature,[8] that ought to be implemented for all laser-assisted
procedures:
- Always discuss alternative therapeutic strategies in a
multidisciplinary team and postpone laser therapy if it is not urgent;
- Perform RT-PCR test for detection of SARS-CoV-2 RNA before every
procedure;
- During routine preoperative exams, non-enhanced chest computed
tomography is reported to have a higher sensitivity for COVID-19
detection than RT-PCR;
- For small and easily accessible lesions, resection by cold instruments
should be preferred;
- Laser surgery should be performed in an operating room with a highly
efficient negative-pressure system;
- Sterilize laser handpieces after use and frequently change surgical
gloves, especially after direct contact with the instrument;
8. All the staff should wear highly protective PPE, including goggles
and gloves and highly protective masks (i.e., N95) with gas
adsorption filters;
9. Disposable double plume evacuation systems with filters that remove
particulates up to 0.1 microns (the so-called ULPA, ultra-low
particulate air filters) should be available;
10. Reduce the presence in the theater of all the unnecessary personnel
and perform adequate training for all staff members to enhance awareness
about the hazards of the surgical smoke in the COVID-19 outbreak.
In this evolving context, head and neck laser-assisted surgery must be
in all cases considered a high-risk aerosol-generating procedure and the
highest attention must be paid to surgical safety until evidence-based
protocols are available.