In this study, the 30% fall in case load during the COVID-19 period and the proportion of local patients in PCG being lower than those in CG could be attributed to the travel restrictions and lockdown imposed on Beijing. During the COVID-19 period, some regulations were issued by Chinese General Hospital of People’s Liberation Army. These regulations were as follows: the medical staffs must wear medical surgical masks or N95 masks, disposable helmets, gloves and goggles to protect them from potential infections.
The use of telemedicine and remote counselling has made great strides during the COVID-19 pandemic. This has helped in avoiding crowds in hospitals and reducing unnecessary physical contacts. Tolone et al. designed and adopted an exhaustive triage questionnaire for elective surgical patients in cases of positive symptoms and contact history associated with COVID-19. These questionnaires were administered through the telephone [11]. Gambardella et al. reported their experience regarding treatment for old cancer patients. They documented several procedures that could help in preventing disease transmission among patients [12]. These procedures encompassed the adoption of a preadmission telephone triage, and the implementation of telemedicine. In CG, appointments and triage protocols were to be performed virtually through telemedicine such as telephone, smartphone apps or the internet and clinical visits were to be performed based on reserved numbers and recommended time. For the primary-care of patients, triage nurses were needed to measure the temperature and investigate the epidemiological history of patients including travel to Hubei Province and nearby cities, contacts with confirmed or suspected cases within 14 days, as well as clinical manifestations including fever (>37.3℃), fatigue and respiratory symptoms like coughing.
The COVID-19 outbreak brought to the importance of infection control measures for pandemic diseases. Successful implementation of infection control measures require the strict management of inpatients during this period. Patients with cancers have been established to be immunocompromised, which makes them more susceptible to COVID-19 [4, 10]. Therefore, we suggest that all outpatients should be triaged before admission to reduce the possibility of exposure in hospital. In CG, to screen for suspected infections, patients were subjected to chest CT scans and new coronavirus nucleic acid tests before admission, which explains the longer waiting time before admission in CG. In addition, the provinces were relatively isolated during the pandemic, therefore, compared with PCG, the proportion of local patients in CG had increased.
After admission, patients were isolated in separate single-room wards without contact to surgeons or nurses. If the fever was lower than 37.3℃ or other symptoms associated with pneumonia were absent after 3 days of admission, surgical procedures would then be performed. The waiting time before surgery was, therefore, longer. During the pandemic, routine surgical techniques should be based on the principles of safety and efficiency, with the main purpose of reducing the incidences of postoperative complications while accelerating the patient's recovery and discharge [13-15]. It is necessary to avoid performing surgical procedures beyond the established guidelines, including oversized lymph node dissections with uncertain effects and complex digestive tract reconstruction methods. For better surgical outcomes, attention should be paid during surgery to reduce the risk of bleeding. This decreases the chances for blood transfusion.
During COVID-19 period, more laparoscopic surgeries were performed. COVID-19 is mainly transmitted through respiratory droplets, but the risk of COVID-19 transmission is greatly increased during aerosol generation procedure (AGP) in laparoscopic surgery [16]. Compared with open surgery, there are concerns that the leaked CO2 and smoke may lead to the generation of COVID-19 contaminated aerosols, which may be due to the application of ultrasonic surgical instruments, low gas motility of pneumoperitoneum, and gas expulsion through trocars or ports [17]. Therefore, The Intercollegiate General Surgery Guidance on COVID-19 and The Society of Gastrointestinal and Endoscopic Surgeons (SAGES) initially highlighted the risk of aerosolization during laparoscopic surgery, although their updated guidance acknowledged a lack of evidence [18, 19].
However, both open surgery and laparoscopy could generate surgical smoke. When necessary preventive measures are taken, smoke control can be achieved in the closed cavity of laparoscopic surgery, while it cannot be properly controlled in open surgery. The key factors for safe control of smoke hazards are smoke evacuation only through filters, complete evacuation of pneumoperitoneum before extraction or conversion to open surgery, clamping of both sides of intestine before transection to avoid stool exposure and intelligent use of ultrasonic surgical instruments.
After a rigorous analysis of the literature on surgical smoke, we conclude that there is no high level of evidence that laparoscopic surgery is routinely prohibited simply because of the risk of aerosol contamination. In particular, there is no evidence that COVID-19 is transmitted via surgical smoke generated by ultrasonic surgical instruments [20-23]. By the way, during the COVID-19 pandemic, we also use smoke evacuator which is designed with a vacuum motor. The motor is used to draw the surgical smoke from the surgical site through the vacuum tubing and into the filter which is completely enclosed to protect the healthcare personnel from potential contamination. However, although we have not found any evidence of particular risk in laparoscopic surgery, the risk might still exist. Further investigation in this field is of critical importance.
Therefore, we use laparoscopy more frequently during COVID-19, and information about laparoscopic surgeries revealed that conducting surgery during COVID-19 is feasible. However, lengths of preoperative, postoperative and total hospital stay were all significantly longer and cost of hospitalization and treatment were notably higher, which was related to a three-day observation and isolation before operation.
During the COVID-19 period, patients had to have their stitches removed in outpatient clinics and local hospitals after discharge. This increased the risk of unnecessary viral infections. It was better to stay longer in our department until stitches were removed. The hospital stay period after surgery was, therefore, longer in CG.
We found no statistically differences in postoperative fever. If the patient developed fever of unknown cause after surgery, appropriate ward isolation measures should be taken and measurements of postoperative blood routine, C-reactive protein, procalcitonin, chest CT, and new coronavirus nucleic acid tests were necessary.
Limitations
This study had some limitations. Firstly, the presented results are for a short-term follow-up period which fails to illustrate the long-term outcomes such as progression-free survival and mortality. Secondly, oversized lymph node dissections with uncertain effects were not performed beyond authoritative guidelines, which may have also impact on oncologic outcome. More studies are needed to investigate the impact of these procedures on oncologic outcomes. Thirdly, the study was retrospectively performed in a single center and may therefore involve selection bias.