key: cord-0905511-3pdd9t08
authors: Jones, Dominique; Faluyi, David; Hamilton, Sarah; Stylianides, Nicholas; Ma, Ken; Duff, Sarah; Machin, Nicholas; Edmondson, Richard J
title: A prospective study to identify rates of SARS-CoV-2 virus in the peritoneum and lower genital tract of patients having surgery: an observational study
date: 2021-02-11
journal: J Minim Invasive Gynecol
DOI: 10.1016/j.jmig.2021.02.006
sha: 553be9c6d1a019c5c4ab716107b8779a5ac884b4
doc_id: 905511
cord_uid: 3pdd9t08

STUDY OBJECTIVE: The risks to surgeons of carrying out aerosol generating procedures during the COVID pandemic are unknown. To start to define these risks, in a systematic manner, we investigated the presence of SARS-CoV-2 virus in the abdominal fluid and lower genital tract of patients undergoing surgery. DESIGN: A prospective cross sectional observational study. SETTING: A single large UK Hospital PATIENTS: O 113 patients undergoing abdominal surgery or instrumentation of the lower genital tract. INTERVENTIONS: We took COVID swabs from the peritoneal cavity and from the vagina from all eligible patients. Results were stratified by pre operative COVID status. MEASUREMENTS AND MAIN RESULTS: In patients who were presumed COVID negative at the time of surgery SARS-CoV-2 virus RNA was detected in 0/102 peritoneal samples and 0/98 vaginal samples. Both cohorts included four patients who were antibody positive but nasopharyngeal sab test negative at the time of surgery. Peritoneal and vaginal swabs were also negative in one patient who had a positive nasopharyngeal swab immediately prior to surgery. CONCLUSIONS: The presence of SARS-CoV-2 RNA in the abdominal fluid or lower genital tract of presumed negative patients is nil or extremely low. These data will inform surgeons of the risks of restarting laparoscopic surgery at a time when COVID19 is endemic in the population. BRIEF FUNDING STATEMENT: There was no external funding of this study

We took COVID swabs from the peritoneal cavity and from the vagina from all eligible patients. 44 Results were stratified by pre operative COVID status. 45

In patients who were presumed COVID negative at the time of surgery SARS-CoV-2 virus RNA was 47 detected in 0/102 peritoneal samples and 0/98 vaginal samples. Both cohorts included four patients 48 who were antibody positive but nasopharyngeal sab test negative at the time of surgery. Peritoneal 49 and vaginal swabs were also negative in one patient who had a positive nasopharyngeal swab 50 immediately prior to surgery. 51

The presence of SARS-CoV-2 RNA in the abdominal fluid or lower genital tract of presumed negative 53 patients is nil or extremely low. These data will inform surgeons of the risks of restarting 54 laparoscopic surgery at a time when COVID19 is endemic in the population. 55 56

There was no external funding of this study 58 However the safety of these procedures, which, when combined with electrosurgery, are known to 75 be aerosol generating (3), is unclear, thus leading to a profusion of conflicting guidance (reviewed 76

in (4)). The presence, although not necessarily infectivity, of other virus particles, including Hepatitis 77 B virus, has been confirmed in laparoscopic aerosols(5), but evidence for the presence of SARS-CoV-78 2 virus is mixed(6) with some single case reports of positive peritoneal fluid(7) whilst others report 79 negative findings(8). Consequently there has been a call from some quarters to abandon minimal 80 access surgery in all patients(4). 81

In the UK, the NHS, like many other health care systems, has attempted to stratify patients by 82

introducing cohort status dependent upon pre-operative cohort status(9). Inclusion in the lowest risk 83 cohorts includes pre-operative isolation and covid testing prior to admission. Despite this risk 84 stratification many centres continue to manage these patients as potentially high risk and have been 85 reluctant to return to the use of minimal access surgery for these groups. 86

Here, we therefore set out to systematically evaluate the risk of SARS-CoV-2 virus being present in 87 the peritoneal fluid and vagina of apparent low risk patients. Although presence of virus would not 88 necessarily confirm infectivity, absence of virus RNA would provide reassurance that the risks of 89 undertaking aerosol generating procedures would be low in these groups. 90

Patients were enrolled into the study at Saint Mary's Hospital, Manchester Royal Infirmary and 93

Wythenshawe Hospital, all part of Manchester University Foundation NHS Trust, between 7 th June 94 and 29 th July, 2020. An abdominal COVID swab was taken as soon as the abdominal cavity was opened. The swab was 117 taken from the pelvis and the paracolic gutters. For laparoscopic cases, the swab was inserted 118 through a 5mm operating port, manipulated using laparoscopic forceps to ensure it was applied 119 firmly to peritoneal surfaces and then removed immediately through the laparoscopic port. 120

Samples were collected in viral transport medium and tested for the presence of SARS-CoV-2 RNA by 121 reverse-transcriptase polymerase chain reaction (RT-PCR) using the Cobas® SARS-CoV-2 RNA assay 122 (Roche, USA). 123

For the purposes of analysis patients were classified into the three risk groups defined by NHS 125

England (9). Many UK centres have adopted these risk groupings as a mechanism for cohorting 126 patients within hospitals. For this study the three groups were therefore defined as: 127

Green (COVID-clear). Patients who self isolate for 14 days prior to admission, undergo negative 128 nasopharyngeal swab within 48 hours of admission (and in the case of patients being admitted to 129 level 2 and 3 care also undergo negative chest imaging) and are treated by teams of clinicians only 130 caring for "green" patients. 131

Amber (undifferentiated). Patients who have not self isolated but are asymptomatic at time of 132 admission, undergo negative nasopharyngeal testing within 4 hours of admission or have suspicious 133

but not diagnostic chest radiological findings. 134

Blue (COVID-positive). Patients who have had positive COVID nasopharyngeal testing, or who have 135 symptoms or radiological findings in keeping with current acute infection. 136

All patients recruited underwent standard screening for active COVID-19 infection using combined 138

nose and throat swabs, tested for SARS-CoV-2 RNA by RT-PCR. 139

Whilst the study was recruiting SARS-CoV-2 antibody testing became available for some patients and 140

these results, where available, were collected from the patient record along with other clinical 141 details. 142

Estimates of the incidence of COVID positivity during the study were derived from UK government 145 websites. 146

As this was an observational study a formal power calculation was not possible. The number to be 148 recruited was therefore estimated using a Bayesian approach. The number needed for the study was 149 defined as the number needed to convince a majority of clinicians that the rate of COVID positivity in 150 a particular cohort is sufficiently low that the benefits of surgery outweigh the risks. 151

Polling a panel of surgeons revealed that a rate of 0/100 for any particular risk group would be 152 sufficiently low risk to convince surgeons that this was a safe procedure. A total number of 100 cases 153 was therefore selected for the study. In this study we were unable to detect any SARS-CoV-2 RNA in either the abdominal cavity or the 182 vaginal fluids of a prospective series of over 100 patients undergoing surgery. 183 Specifically, the numbers of "green" (n=27) and "amber" (n=84) patients included here provides 184 reassurance that the risks in these two groups are extremely low and that surgery in patients who 185

have tested negative preoperatively could be undertaken safely, including minimal access surgery as 186

appropriate. 187

Interestingly we were unable to detect virus in the 4/32 (13%) patients who had positive antibody 188 titres and the one patient who had active infection at the time of surgery. These numbers remain 189 too small to make strong recommendations but we will continue to recruit these subgroups of 190 patients for further study. 191

Although the detection of virus particle in vaginal and abdominal fluids would not necessarily 192 indicate infectivity as virus may be destroyed through the process of heating required to generate a 193 surgical plume or aerosol the absence of virus particle in vaginal and abdominal fluids tested here is 194 reassuring. 195 This study was carried out at a time when the community incidence rate of COVID infection was 196 estimated to be stable at 0.02% (11). This rate of infection would seem to represent the ongoing 197 endemic rate which is likely to persist for at least a period of months. 198

Our study was weighted towards the inclusion of patients undergoing caesarean section as this is 199 currently the commonest abdominal operation being carried out in our institution. Nevertheless we 200

were able to include patients undergoing other procedures including oncology surgery and 201 emergency general surgical procedures. There is no reason to suppose that the population included 202 in this study is particularly different from the general obstetric, gynaecological or surgical 203 population. 204

This study did not include any patients in whom there was faecal contamination of the abdominal 205 cavity at the time of surgery. Further studies are now underway to address this and also to assess 206 risk in asymptomatic and symptomatic COVID positive patients, and those who have positive 207

antibodies. 208

In summary we have demonstrated that undertaking abdominal and gynaecological surgery, 209 including laparoscopic surgery, in patients who have been COVID tested pre operatively, whether 210 they have been self isolating or not, must be considered a low risk procedure. These data will allow 211 surgeons, and their teams, to make informed decisions about returning to laparoscopic surgery, the 212 role of filtration devices, and the need for PPE in low risk patients who comprise the majority of 213 patients currently awaiting a surgical procedure. 

Improved surgical safety after laparoscopic compared to open surgery 256 for apparent early stage endometrial cancer: results from a randomised controlled trial

Suspected cancer: recognition and referral (NG12)

Surgical Smoke Exposure in Operating Room 260 Personnel: A Review

The risk of COVID-19 transmission by laparoscopic smoke may be lower than 262 for laparotomy: a narrative review

Detecting hepatitis B virus in surgical smoke emitted during laparoscopic 264 surgery

SARS-CoV-2 is present in peritoneal fluid in COVID-19 patients. Annals of 266 Surgery

SARS-Cov-2 in peritoneal fluid: an important finding in the Covid-19 268 pandemic

SARS-Cov-2 Was Not Found in the Peritoneal Fluid of an 270

Asymptomatic Patient Undergoing Laparoscopic Appendectomy

The Strengthening the Reporting of Observational Studies in Epidemiology 275 (STROBE) statement: guidelines for reporting observational studies

Coronavirus (COVID-19) Infection Survey pilot: 278 England

SARS-CoV-2 is undetectable in the abdomen and vagina of patients undergoing surgery