Crucial updates to decisions in lap vs open surgery with COVID-19

Laila Zomorodian, MD and Zachary Elliott, MS2

Though we await definitive evidence, minimally invasive surgical approaches may actually be more favorable than open procedures in limiting spread of COVID-19, an update from earlier suppositions within the surgical community. Out of an abundance of caution, the March 29 SAGES guidelines recommend using CO2-filtering devices during minimally invasive cases, given prior data indicating infectious particle aerosolization from surgical smoke with HPV, HBV, HIV, and various malignancies. Much of that literature, however, came from the 1980s and 90s, before multiple advancements in thermal instruments and filtering devices.

SARS-CoV-2 is an RNA virus ranging 0.06 to 0.14 microns in diameter. However, various systems vary in filtering efficiency:

• N95 masks: 95% of particles > 0.3 microns

• HEPA filters: > 99.97% of particles > 0.3 microns

• PAPRs use HEPA filters (high-efficiency particulate air filters), which are as efficient as P-100 filters and will protect against SARS.

• ULPA filters: 99.999% of particles > 0.05 microns (or 0.1 microns per AORN)

Given these findings, SAGES recommends a multi-faceted best practice approach for ALL cases, including endoscopy: proper room filtration and ventilation, appropriate PPE, and smoke evacuation devices with a suction and filtration system. Consider PAPR over N95 for intubation, extubation, bronchoscopy, endoscopy, and tracheostomy.

SAGES measures for smoke filtration and evacuation: our summary

1. Do not vent any ports once placed, if possible.

• If insufflation must be switched to a different port, close the first port before disconnecting the tubing, and keep the new port closed until the insufflator tubing is connected and the insufflator is confirmed to be “on” before the new port valve is opened (avoid back-flow into insufflator)

2. Desufflation

• Evacuate all pneumoperitoneum from the filtration port before specimen extraction, conversion to open, trocar removal, or closure.

• On desufflation, capture smoke with an ultra-filtration system. Have insufflator on “desufflation mode” if available; if not, close the valve on the insufflating port BEFORE insufflator flow is turned off to avoid contaminated intra-abdominal CO2 from pushing back into the insufflation tubing.

• Keep patient flat; use the least dependent port for desufflation.

3. Only AFTER desufflation and complete gas/smoke evacuation

• Specimen removal; including wound protectors and hand-assist incisions in cases of larger specimens

• Drain placement (only if absolutely necessary)

• Close fascia; avoid closing port sites with suture closure devices/procedures that allow leakage of insufflation

Other notes include:

• Air Seal: Does not filter viral particles. Solution: connect another smoke evacuator or suction irrigator WITH an ULPA filter, to another port

• Ultravision: may suppress aerosolization from pneumoperitoneum when used in adjunct with another smoke evacuator

• Wall suction: does not use ultrafiltration

Links to table references: ConMed response to SAGES recommendations, Insufflation recommendations, smoke evacuation recommendations, AirSeal System Filtration Sheet, and AirSeal Smoke Evacuation Mode.

Stryker Response to SAGES-EAES Recommendations