According to a new worldwide study, surgery should be delayed by seven weeks after finding positive to COVID-19, as interventions performed up to six weeks after diagnosis are associated with an increased risk of mortality.

Researchers proved that patients have more than two and a half times the probability of death after the surgery if the procedure takes place in the six weeks following a positive diagnosis for SARS-CoV-2

Led by experts from the University of Birmingham, more than 25,000 surgeons cooperated within the COVIDSurg group to collect data from 140,727 patients in 1,674 hospitals in 116 countries, including Australia, Brazil, China, India, Italy, United Arab Emirates, United Kingdom and United States, creating one of the largest studies in the world in surgery. For Italy, Dr. Salomone di Saverio (University of Varese), Gaetano Gallo (University of Catanzaro), Francesco Pata (Ospitale Nicola Giannettasio, Corigliano-Rossano, CS) and Gianluca Pellino (University of Campania "Luigi Vanvitelli") participated as members of the Dissemination Committee. As many as 115 hospitals took part in the study in Italy.

Publishing their results in Anesthesia, the researchers revealed that patients who underwent surgery from 0 to 6 weeks after being diagnosed with SARS-CoV-2 infection were at increased risk of postoperative death, as were patients with ongoing symptoms at the time of surgery.

The co-lead author, Dr. Dmitri Nepogodiev of the University of Birmingham commented: "We recommend that, whenever possible, surgery be delayed for at least seven weeks after a positive SARS-CoV-2 test result or until symptoms resolve, if patients have symptoms for 7 weeks or more after diagnosis. "

Co-lead author, Aneel Bhangu, of the University of Birmingham, added: "Decisions regarding the delay of surgery should be tailored to each patient, as the possible benefits of a minimum delay of seven weeks after the diagnosis of SARS- CoV-2 must be balanced against the potential risks of delay. For some urgent surgeries, such as advanced cancers, surgeons and patients may determine that the risks of delay are not justified. "

Although SARS-CoV-2 infection during surgery is known to increase mortality and international guidelines recommend that surgery should be delayed for patients who test positive for COVID-19, there is little evidence regarding the optimal duration of the postponement.

Participating hospitals included all patients who underwent surgery in October 2020. Patients who became infected with SARS-CoV-2 after surgery were excluded from the study. The primary outcome measure was postoperative death at 30 days.

A dedicated statistical modelling was used to calculate the 30-day mortality rates.

The time from SARS-CoV-2 diagnosis to surgery was 0-2 weeks in 1,144 patients (0.8%), 3-4 weeks in 461 patients (0.3%), 5-6 weeks in 327 patients (0.2%), 7 weeks or more in 1,205 patients (0.9%), while 137,590 (97.8%) had no SARS-CoV-2 infection. The corrected 30-day mortality in patients who did not have SARS-CoV-2 infection was 1.5%. This latter figure was increased in patients who underwent surgery at 0-2 weeks (4.0%), 3-4 weeks (4.0%) and at 5-6 weeks (3.6%), but not at 7-8 weeks. (1.5%) after the diagnosis of SARS-CoV-2.

These results were consistent across age groups, different severity of the patient's condition, urgency and class of surgery, and in sensitivity analyzes for elective surgery. After waiting for surgery for seven weeks or more, patients with ongoing COVID-19 symptoms (6.0%) experienced higher mortality than patients whose symptoms had resolved (2.4%) or who had been asymptomatic (1.3%).