The decision to perform surgeries in the face of the pandemic requires a thorough evaluation to establish priorities and define precisely in which cases benefits overcome risks, and surgery is genuinely needed [9,16]. This was a great challenge for surgeons in 2020, since avoiding unnecessary activities in healthcare facilities, thus canceling or postponing all non-urgent procedures, was widely stated as an important measure to prevent overload and enable reorganization of the healthcare systems worldwide [9-11]. The Brazilian public health system adhered to these recommendations, as shown by the decrease of elective surgeries in 2020 (34.82%) compared to the decline in urgent procedures (1.1%).

When analyzing monthly surgical procedures in 2020, there was a remarkably low number of surgeries between April and June, the months following the country’s first reported cases, resuming growth from July onwards. Indeed, regulatory measures must be more restrictive at the beginning of an outbreak, when healthcare systems are unprepared to deal with a possible overload, so time is needed until more health resources can be acquired [9,10]. There was a new reduction rate in December when compared to the previous months. In the past years (2017-2019), there was a seasonal decrease in hospitalizations for surgical procedures in November and December [17]. Still, the reduction in 2020 could also be attributed to the increase in COVID-19 cases that took part in Brazil in November [18].

Even though Brazil has considerable differences in public administration, heterogeneous cultural and economic conditions across different regions, data shows similar reduction rates in hospitalizations when comparing the rates in 2020 with the previous years, with an average reduction of 18.96%. However, in the 2020 monthly comparison, there was a higher decrease rate in the North in December when compared to the other regions. These reductions might have been the result of the regional healthcare system collapse in December [19].

Surgical care that is not time-critical can be delayed to a later date when the pandemic subsides. However, certain procedures must be performed even during a pandemic, such as cancer treatment and urgent surgeries, as these are considered life-saving procedures [9]. This could explain why oncology and thoracic surgeries suffered minor reductions in the ranking, while endocrine gland surgery was the subgroup with the highest decrease rates (48.03%), probably due to the possibility of safe deferral of these procedures [16,20,21].

Regarding plastic surgery, guidelines support the deferral of breast reconstruction and revision procedures [22], which might explain the high decrease rates in breast surgery (40.68%). Other studies have found that plastic surgery procedures most impacted by the pandemic were superficial skin lesions and subcutaneous mass procedures [23], which corroborates our findings of high decrease rates in minor surgeries and surgeries of skin, subcutaneous tissue and mucosa (33.16%).

Other subgroups with the highest decrease rates were oral and maxillofacial (37.3%) and upper airways, head and neck (36.06%) surgeries. These procedures were of particular concern due to the higher risk of generating aerosols. Guidelines recommend these surgeries should only be performed in life-threatening conditions with great precautions due to the possibility of COVID-19 infection [22,24].

There were also important decrease rates among surgeries of the digestive system and abdominal wall (30.16%), which may also reflect recommendations and alternative management of digestive emergency conditions performed during the pandemic. Guidelines support that only life-threatening gastrointestinal conditions should undergo surgery, and there were recommendations for clinical treatment in conditions such as uncomplicated appendicitis and cholecystitis [17,23], situations in which conservative management appears to be effective and reduce the length of hospital stay [25].

Cancer surgery was one of the challenges faced in the context of the pandemic. Since both cancer and surgical patients are at high risk of COVID-19 infection and complications of the disease [26-28], there was a concern involving the exposure of these patients to the hospital environment, and most guidelines supported that surgeries should be delayed whenever possible. On the other hand, there were concerns about the risks of postponing oncological procedures and the exposure of patients undergoing conservative cancer treatment. The recommendation was that decisions should be made based on the clinical condition and the pandemic’s impact on the local healthcare system [22,27,28]. This study found only a 5.6% reduction in general oncological surgeries, which suggests that Brazil had a trend in choosing for operation in most cancer cases.

Hospitalization rates for obstetric surgery were slightly higher in 2020 than the average from 2016 to 2019 (0.48% increase). Brazil is one of the countries with the highest cesareans rates, which consisted of 56.3% of all deliveries in 2019 [29]. Since most guidelines support that maternal COVID-19 infection should not influence the type of delivery [30], it should be safe to assume that the pandemic did not significantly impact this group of procedures.

COVID-19 has had a devastating impact on patients, the economy and healthcare systems. There is hope that cases will begin to decline soon and, as the COVID-19 vaccine is distributed, hospitals must develop protocols to resume elective surgeries safely. This will be the next challenge for the surgical community. Moving forward requires not only creativity but also structural changes to patient workflows [31-33].

Regarding the long-term effects on surgical practice, this pandemic should raise awareness regarding protective measures to both surgical staff and patients, and the protocols’ changes made to reduce the risk of contamination during surgical procedures should be added to operating theaters routines.

This study has limitations: the data refer only to the Brazilian public health system because data from the private health system are not available, which might lead to an overestimation of the decrease rates. As secondary data, the veracity of the information provided depends on proper registration.

Although regression analyses that could help explain the differences in the number of surgeries between subgroups and regions were not performed, some justifications for the temporal trends of reduction in surgical procedures are speculated, such as the correlation with decrees and laws of state and municipal governments that imposed the postponement of elective surgeries.