New research suggests it is safe to operate on patients 2 weeks after a positive COVID test, rather than the current recommendation of 7 weeks, so long as they have recovered.
Surgical decision making after SARS-CoV-2 infection is influenced by “the presence of comorbidity, infection severity, and whether the surgical problem is time-sensitive”, explained the authors of the new study, published in the journal Anaesthesia.
Findings from the previously conducted 'COVIDSurg collaborative' had suggested surgery should be delayed for 7 weeks after a positive COVID test, having identified an increased risk of postoperative (30-day) mortality and lung complications up to 7 weeks following a positive test even in patients who had recovered fully. In that study, mortality was 9.1% within 30 days for surgery within 2 weeks of a positive COVID test, reducing to 2.0% for surgery 6 weeks or more after a positive test. However, that study was conducted before vaccines or evidence-based drug therapy for severe COVID became available, the authors pointed out.
Despite UK and German guidance still recommending deferring elective surgery for 7 weeks after SARS-CoV-2 infection, in other countries the guidance differs - the United States recommends 7 weeks of postponement in unvaccinated individuals only, and guidance from Australia and New Zealand recommends stratification by surgical magnitude, with postponement ranging from 4 weeks for minor to 12 weeks for major surgery.
"Contemporary surgical policy-making is, therefore, constrained by very heterogeneous global guidance," warned the authors, who cautioned that "all else being equal, delaying surgery usually leads to worse outcomes". They illuminated that scheduling constraints might limit the capacity of health services to clear the post-pandemic backlog of cancer and other elective surgery, and that the postponement of potentially curative cancer surgery could worsen overall survival.
Risk Lower Than Previously Thought
So the researchers set out to analyse afresh the safety of surgery following COVID infection in both the era with COVID vaccines, and the era of the pandemic before vaccines, and whether deferral remained necessary.
Using the OpenSAFELY platform - a secure and transparent platform linking data from two major NHS primary care record providers with relevant databases from secondary care and with the Office of National Statistics - they analysed 3,658,140 patients who underwent surgical procedures in England between 17 March 2018 and 17 March 2022, 2 years before and 2 years after 17 March 2020 when all elective surgery in the UK was temporarily postponed as part of the first COVID lockdown. A total of 1,242,180 surgeries were conducted since vaccines became widely available, on patients with a mean age of 55 years.
Overall, 30-day post-operative mortality was less than 0.2% and 30-day post-operative complications under 1% in the pandemic-with-vaccine era. Mortality for surgery conducted within 2 weeks of a positive test was 1.1%, declining to 0.3% by 4 weeks. This compared with 9.1% and 6.9%, respectively, in COVIDSurg.
Even when the authors looked at the pre-vaccine pandemic period - the era covered by COVIDsurg - results from the new study showed lower mortality in England than in the global sample: 4.1 % for surgery conducted within 2 weeks of a positive COVID test, declining to 1.3% by 4-6 weeks and 0.9% by 6 weeks and over.
The authors pointed out that it was important to note that in any 6-month window fewer than 3% of surgeries were conducted within the 7-week threshold after a positive PCR assay. This demonstrated that most UK hospitals were sticking to the 7-week no surgery window following a positive COVID test, as suggested by the COVIDSurg study. They emphasised that even though a higher proportion of emergency than elective surgery was conducted within 7 weeks of a positive SARS-CoV-2 test, this was again, “always less than 3% of the emergency surgical caseload”.
Dr Alwyn Kotzé, consultant anaesthetist, School of Medicine, University of Leeds, and co-author, commented that this first large-scale analysis of surgical outcomes throughout the COVID-19 pandemic timeline suggested that in England surgical patients’ overall risk following an indication of SARS-CoV-2 infection “may be lower than previously thought”.
7-Week Threshold Should Be Reduced
If the risk associated with surgery after SARS-CoV-2 infection is much lower than previously thought, delaying surgery might cause “more harm than good”, particularly in patients who have already waited longer than is desirable for surgery, the authors alerted.
“In most cases, it will be safe to carry out planned surgery from 2 weeks after a positive COVID test, as long as the patient has recovered – compared with current guidance that recommends delaying surgery for 7 weeks,” reassured the authors.
This would bring down the suggested delay for surgery from the current recommendation of 7 weeks down to 2 weeks, they said.
The authors noted some study limitations, including that the findings should not be used to guide decision-making for higher-risk groups – for example, those who remain symptomatic beyond the acute phase of COVID-19, or those individuals who are immunosuppressed - since the statistics represented the overall general patient population and did not reveal the heightened risk experienced by these groups. Furthermore, they cautioned, their study “should not be used to infer similarity to cohorts other than surgical patients”, since the study was a service evaluation rather than generalisable research.
“Given that delaying surgery is likely to worsen patient outcomes in the longer term, we recommend that UK guidelines should reduce the seven-week threshold for low-risk patients who have fully recovered after a positive SARS-CoV-2 test,” Dr Kotzé opined. He suggested that surgery be delayed for “no more than 2 weeks” after testing positive for SARS-CoV-2 infection, unless there were specific circumstances that placed an individual at higher risk of poor outcomes.
“This would bring clinical guidance on surgical timing after an indication of SARS-CoV-2 infection into line with common practice regarding other acute respiratory infections,” he indicated.
Professor Ramani Moonesinghe, University College London, and NHS England national clinical director for critical and perioperative care, and co-author, said: "This analysis provides new and important data on the safety of surgery after COVID infection, and should provide reassurance to patients and clinicians.”
The authors also recommended that other countries evaluated their surgical services to assess whether country-specific guidelines were followed and whether interventions were still appropriate.