Existence of SARS-Cov-2 in the Peritoneal Fluid

Objective  To determine the existence of SARS-CoV-2 in the peritoneal fluid to assess the risk of exposure through surgical smoke and aerosolization threatening healthcare workers during abdominal surgery. Background  SARS-CoV-2 is a respiratory virus and possible ways of viral transmission are respiratory droplets, close contact, and fecal-oral route. Surgeries pose risk for healthcare workers due to the close contact with patients. Aerosolized particles may be inhaled via the leaked CO 2 during laparoscopic procedures and surgical smoke produced by electrocautery. Methods  All the data of 8 patients, who were tested positive for COVID–19, were collected between August 31, 2020 and April 30, 2021. Recorded clinicopathologic data included age, symptoms, radiological and laboratory findings, antiviral treatment before surgery, type of surgery and existence of the virus in the peritoneal fluid. Nasopharyngeal swab RT-PCR was used for the diagnosis. COVID–19 existence in the peritoneal fluid was determined by RT-PCR test as well. Results  All 8 COVID–19 positive patients were pregnant, and surgeries were cesarean sections. 1 of the 8 patients was febrile during surgery. Also only 1 patient had pulmonary radiological findings specifically indicating COVID-19 infection. Laboratory findings were as follows: 4 of 8 had lymphopenia and all had elevated D-dimer levels. Peritoneal and amniotic fluid samples of all patients were negative for SARS-CoV-2. Conclusion  SARS-CoV-2 exposure due to aerosolization or surgical fumes does not seem to be likely, provided the necessary precautions are taken.


Introduction
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak was declared as a pandemic by the World Health Organization (WHO) on January 30, 2020. 1 The disease initially appeared in China and spread to many other countries rapidly. Human to human transmission was demonstrated shortly after the outbreak and the virus infected millions of people around the world in the following months. Early reports showed the mortality rate as 2.3% in China while as %1.6 in other countries. 2 SARS-CoV-2 is a respiratory virus and possible ways of viral transmission are respiratory droplets, close contact, and fecal-oral route. 3 Operating rooms (OR) are among risky places in situations like viral outbreaks because patients and healthcare workers are often in close contact. National and international surgical guidelines still evolve to protect healthcare workers from the risks posed by their colleagues and patients.
Inhalation of aerosolized particles is considered as a risk factor for transmission of SARS-CoV-2. 4,5 Surgical smoke due to electrocautery or the leaked CO2 that is used during laparoscopy may be inhaled in the OR. Mintz et al. claimed that laparoscopy should be used if the procedure is more suitable for the patient. They also stated that more evidencebased research is needed to determine the safety of laparos-copy. 5 Viral load of the peritoneal fluid seems to be the main factor that increases the risk of transmission through inhalation of leaked laparoscopic gases and smoke due to electrocautery.
This study was designed to evaluate patients, who were tested positive for COVID-19 and underwent obstetrical surgery, regarding the presence of viral genome in the peritoneal cavity.

Methods
All women, who underwent surgery and had positive COVID-19 test results, at Dokuz Eylul University Hospital Department of Obstetrics and Gynecology between August 31,2020 and April 30, 2021 were included in the study. The diagnosis was determined with nasopharyngeal swab test. A positive test was defined as a positive result for SARS-CoV-2 with reverse transcriptasepolymerase chain reaction (RT-PCR) assay. Ethical approval for the study was obtained from the local ethics committee of Dokuz Eylul University Hospital (No:2021/04-41). Written informed consent forms were obtained from all participants.
The study was designed as a prospective study. The hospital electronic patient database provided epidemiological, clinical, laboratory and radiological data of the patients.
Nasopharyngeal swab specimens were tested for SARS-CoV-2 at the microbiology laboratory of the same institution. The test was conducted by using virus mini kit (EZ1 Virus Mini Kit v2.0, Germany), followed by RT-PCR according to WHO guidelines.
Birth weight and gestational age at the delivery were recorded. Amniotic fluid samples were collected in addition to peritoneal irrigation fluid for the pregnant patients during the cesarean section (C/S). Peritoneal cavity was irrigated with 10 mL of saline solution and then the irrigation fluid was aspirated for testing. Peritoneal washing aspirate was also used by other researchers. 6,7 The peritoneal fluid sample was obtained before hysterotomy to prevent contamination. Testing for COVID-19 was performed 24/7 in the institution and therefore specimens were transferred to the laboratory momentarily in sterile vials provided by the laboratory. All biological samples were tested for SARS-CoV-2 with the same kit that was used for the nasopharyngeal specimens followed by RT-PCR according to WHO guidelines.
All analyses were performed by using IBM SPSS Statistics Version 25. Only descriptive statistics were calculated and given. Mean AE standard deviation was used to present the data.
This study was performed in consensus with our universitý s ethics guidelines. The ethics committee approval was obtained for this study (No:2021/04-41).

Results
The mean age of patients was 28 AE 2 years. All patients, who underwent surgery when they were tested positive for COVID-19, were pregnant and all surgeries were cesarean sections. 3 of 8 (37.5%) patient were in their first pregnancy. All patients were at term during birth and only one of them was symptomatic while the other 7 were clinically asymptomatic. The symptomatic patient's body temperature was 39C during admission. This patient was operated 4 days after the onset of fever. Due to pregnancy, ionizing radiation was avoided and no patient had radiological imaging except obstetrical ultrasonography preoperatively. However, computerized tomography (CT) scanning was performed on one patient after birth (case 6). Groundglass opacities and patchy lung consolidations were detected in the CT scan. None of the patients received antiviral medication preoperatively (►Tables 1 and 2).
Blood samples from all patients were tested within 24 hours before surgery. Complete blood count, serum c-reactive protein (CRP), alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine concentrations and plasma ddimer concentrations were recorded. Lymphopenia was detected in 4 of 8 patients and plasma ddimer concentration was high in all 8 patients as laboratory findings related with COVID -19 infection (►Table 3).  Cesarean sections were performed in an isolated operating room. The average birth weight was 3282 AE 191 g. Peritoneal irrigation fluid and amniotic fluid samples were tested for SARS-CoV-2 and all samples were determined to be negative.

Discussion
There is limited data regarding intraoperative aerosolization of SARS-CoV-2 at the moment. Many medical institutions have different protocols for urgent and elective surgeries. Our institution requires all patients, who are planned to be operated, to be tested for COVID-19 preoperatively both for elective and urgent procedures. Exceptionally urgent procedures may commence before the test result is obtained. The patients in the study were all cases of cesarean section. Since it was possible to postpone other gynecological procedures at least until the patient's test becomes negative, only obstetrical procedures were performed while the patient had active infection.
Personal protective equipments (PPE) should be used by all healthcare staff, who may be in contact with COVID -19 positive patients, including surgeons, nurses, anesthesiologists and other personnel. Current knowledge is that SARS-CoV-2 is a respiratory virus and possible ways of viral transmission are respiratory droplets, close contact, and fecal-oral route. [8][9][10][11] Airborne transmission has been Although airborne transmission may be considered as an unlikely way for viral transmission, past experiences on the SARS-CoV outbreak shows us aerosol-generating procedures such as tracheal intubation can have the possibility to spread the disease. 12,13 However, there is limited data regarding the management of procedures that can result in aerosolization of  There are several studies that investigated the viral existence in the peritoneal fluid. 7,14 According to our research, there is only one study that demonstrated viral genome in the peritoneal fluid while other studies did not. 15 Absence of the virus may be due to the size of the virus and the pores of the peritoneal membrane. Peritoneal membrane has pores with a maximum diameter of 20-40 nm, in contrast with the diameter of the virus, which is $125 nm. 16 SARS-CoV-2 was not detected in the peritoneal fluid according to a case report that investigates SARS-CoV-2 existence in the peritoneal cavity of a non-perforated appendicitis patient. 7 The variation of test methods can play a crucial role in the test results. 20% or even more false negative rates were declared according to the methods of the tests. 17 There are several studies evaluating the viral presence of hepatitis B virus (HBV), human papillomavirus (HPV), and human immunodeficiency virus (HIV) in surgical smoke. All these viruses were detected in the surgical smoke. [18][19][20][21][22] On the other hand, during earlier viral outbreaks, the transmission of other coronaviruses such as SARS-CoV and MERS-CoV through surgical smoke or laparoscopic gas was never confirmed. 23 Limited controversial data regarding the existence of SARS-CoV-2 in the peritoneal fluid, does not seem to create grave concerns for laparoscopic surgery or using Table 3 Laboratory findings of the patients  Most of the patients were asymptomatic and this may be considered as a limitation, since severe cases concomitantly might have higher viral load and a higher probability of viral presence in the peritoneal fluid. Nevertheless, in the light of our findings, laparoscopic surgery or electrocautery usage should not be avoided due to COVID-19 when indicated and performed under required safety precautions. Our data will contribute to the literature and eventually also help to improve the surgical guidelines for COVID-19 patients.

Conclusion
SARS-CoV-2 was not detected in the peritoneal fluids or amniotic fluids of all 8 patients with positive nasopharyngeal test results. Apparently, C/S is not a laparoscopic technique and does not provide an ideal example to assess the risks of laparoscopic surgeries. However, the key point is the virus presence in the peritoneal fluid. Although our study is helpful to understand the risk of aerosolization of SARS-CoV-2 during laparoscopy and electrocautery usage, further studies are needed in the field of surgical safety during the COVID-19 pandemic.

Contributions
OI: conception and design, analysis and interpretation of data, statistical analysis MEO: acquisition of data, drafting of manuscript OA: acquisition of data, technical support BE: analysis and interpretation of data HTT: drafting of the manuscript OED: critical revision of the manuscript for important intellectual CP: supervision

Conficts to Interest
The authors have no conflict of interest to declare.