Prior to conducting this study, the researchers took into account the recommendations issued by different professional groups such as the IFSO and ASMBS [5-7,26]. These groups considered BMS essential, and therefore the safety goals were met and adequate triage was performed to identify patients with potential SARS-CoV-2 infection.
Participant Selection
This study was evaluated and approved by the local ethics and research committee of the hospital. Each patient gave written informed consent for their data to be used for research and publication.
This research included two study groups: the team of health care professionals (surgical team group) and the patients scheduled for elective BMS (BMS patient group). The inclusion criteria for the BMS patient group included U.S. national patients scheduled for elective BMS at the Baja Hospital & Medical Center in June 2020. Elimination criteria included patients under 18 years old, BMI <30 kg/m2, and chronic diseases that contraindicate the surgical procedure (e.g., lung cancer). Exclusion criteria included patients with a diagnosis of COVID-19, patients with symptoms related to COVID-19 (e.g., fever), and patients with an infectious disease for which BMS was contraindicated or not recommended at that specific time (e.g., community-acquired pneumonia). The group selection schema is shown in Figure 1. The surgical team group included the surgeon, the surgeon’s surgical assistant, the anesthesiologist, and the surgical nurse and circulating nurses, and the same personnel were involved in all surgical procedures.
Preoperative Assessment and COVID-19 Screening
Both groups were screened to confirm the absence of SARS-CoV-2 infection prior to surgery; in the surgical team group, COVID-19 status was determined before the study began (May 28th), using chest CT scans and RT-PCR as diagnostic tools. Due to the limitations of RT-PCR and a shortage of RT-PCR kits (which are mainly destined for public hospitals and health care workers), as well as handling and processing difficulties (especially in that period of time in our locality and country), it was not possible to use the RT-PCR as a diagnostic tool in the BMS patient group. However, on the basis of previous good diagnostic performance in asymptomatic individuals [23], chest CT scans were employed as mandatory COVID-19 screening and categorized according to the COVID-19 Reporting and Data System (CO-RADS) (Table 1). Patients classified as category 1 (very low suspicion of COVID-19) and category 2 (low suspicion of COVID-19) were considered safe to perform BMS, and for patients classified as category ≥3 (indeterminate to very high suspicion of COVID-19), BMS was canceled. The chest CT scans were performed preoperatively, one day before surgery or in some cases on the day of surgery (depending on the day of arrival and the scheduled date of surgery).
For the BMS patient group, a preoperative selection algorithm was developed in order to follow a standardized protocol (Figure 2) from the patients’ arrival to their admission into the hospital. Additionally, in the BMS patient group, a complete preoperative assessment was performed, including a verification of the COVID-19 self-assessment (Appendix 1) and COVID-19 questionnaire (Appendix 2), a preoperative evaluation by the Internal Medicine Department that included the patient’s medical history, a physical examination, and assessment of clinical characteristics (weight, height, BMI, and comorbidities).
BMS Surgical Procedures
Four standardized types of laparoscopic BMS were performed: sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), one anastomosis gastric bypass (OAGB), and bariatric revisional surgery. Surgery selection was based on the individual needs of each patient. All surgeries were conducted under general anesthesia. The surgical team group wore full protection (surgical equipment, N95 or P100 masks, and face shield, depending on personal preference) during all the procedures.
Follow-Up and Outcome Assessment
In the surgical team group, COVID-19 status was determined by RT-PCR and chest CT scan after the surgical procedures for June were completed (July 3). The BMS patient group was followed up for 28 days after surgery to monitor for SARS-CoV-2 infection (the primary outcome) and the development of postoperative complications, adverse effects, and deaths (secondary outcomes). The postoperative follow-up of this group was performed via phone calls by a certified bariatric nurse from the American Society for Metabolic and Bariatric Surgery (ASMBS) on the 14th and 28th postoperative day. The follow-up phone calls consisted in directed questioning to determine the development or presentation of symptoms or signs of COVID-19. If patients reported positive symptoms or signs of COVID-19 in the follow-up period, they were asked to take a RT-PCR test to confirm the presence of the disease. Postoperative complications, adverse effects, and deaths were also assessed by phone calls on the 14th and 28th day after surgery. These calls consisted in a debriefing focused on the most common immediate complications of BMS (e.g., wound problems, pulmonary embolism, leaks, stenosis, internal hernias, port-site hernias, etc.).
Statistical Analysis
For the statistical analysis of this study, firstly we analyzed the clinical characteristics, including age, sex, weight, height, BMI, and comorbidities including hypertension (HTN), type 2 diabetes mellitus (DM2), obstructive sleep apnea syndrome (OSA), hypothyroidism, dyslipidemia, psychosocial disorders, and others (musculoskeletal disorders, migraine, insomnia, and dermatologic disorders) for the entire sample of participants. Then the sample was divided into groups—the surgical team group and the BMS patient group—for which the clinical characteristics and comorbidities were examined. Subsequently, the participants from the BMS patient group were stratified into subgroups based on the surgical technique performed (SG, RYGB, OAGB, bariatric revisional surgery), and finally, COVID-19 and postoperative complications during the follow-up period (phone calls on the 14th and 28th day after surgery) were reported. Descriptive statistics were used to evaluate the primary and secondary outcomes.
To ensure the quantitative variables were correctly reported, the data distribution was first verified with the Kolmogorov-Smirnov test; variables with normal distribution are presented as the mean and standard deviation, and variables that were not normally distributed are presented as the median and interquartile range (IQR). Nominal and categorical variables are presented as proportions; absolute frequency and percentages were used. SPSS version 25 software was used for statistical analysis.