Early experience of aortic surgery during the COVID‐19 pandemic in the UK: A multicentre study

Abstract Background A significant restructuring of the healthcare services has taken place since the declaration of the coronavirus disease 2019 (COVID‐19) pandemic, with elective surgery put on hold to concentrate intensive care resources to treat COVID‐19 as well as to protect patients who are waiting for relatively low risk surgery from exposure to potentially infected hospital environment. Methods Multicentre study, with 19 participating centers, to define the impact of the pandemic on the provision of aortovascular services and patients' outcomes after having adapted the thresholds for intervention to guarantee access to treatment for emergency and urgent conditions. Retrospective analysis of prospectively collected data, including all patients with aortovascular conditions admitted for surgical or conservative treatment from the 1st March to the 20th May 2020. Results A total of 189 patients were analyzed, and 182 underwent surgery. Diagnosis included: aneurysm (45%), acute aortic syndrome (44%), pseudoaneurysm (4%), aortic valve endocarditis (4%), and other (3%). Timing for surgery was: emergency (40%), urgent (34%), or elective (26%). In‐hospital mortality was 12%. Thirteen patients were diagnosed with COVID‐19 during the peri‐operative period, and this subgroup was not associated with a higher mortality. Conclusions There was a significant change in service provision for aortovascular patients in the UK. Although the emergency and urgent surgical activity were maintained, elective treatment was minimal during early months of the pandemic. The preoperative COVID‐19 screening protocol, combined with self‐isolation and shielding, contributed to the low incidence of COVID‐19 in our series and a mortality similar to that of pre‐pandemic outcomes.


| INTRODUCTION
Severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease 2019 (COVID- 19), was first described a as cluster of cases of pneumonia at Wuhan (China) on the 31 December 2019. 1 The number of cases exponentially increased and spread rapidly to other geographical locations, reaching the status of a global pandemic on the 11 March 2020. 2 An extensive restructuring of the healthcare services has taken place due to the need for reallocation of intensive care resources to treat patients with COVID-19. In the United Kingdom (UK) elective surgery was put on hold during the early months of the pandemic to concentrate resources on acute services as well as to protect surgical patients from exposure to potentially infected hospital environments. 3 At the beginning of the lockdown in the UK, we redefined the current guidelines for treatment of aortovascular pathologies and adapted the thresholds for intervention to the current service provision. 4 A multicentre service evaluation study was designed to assess the effects of the COVID-19 pandemic on the delivery of services and clinical outcomes of the aortovascular patients. In this article, we report the initial experience in the UK during the early months of the pandemic.

| METHODS
Retrospective analysis of prospectively collected data from all patients who were admitted with aortovascular pathologies (aortic root, ascending aorta, arch, descending thoracic aorta, and/or thor- The anonymized patient data from individual centers were transferred securely to St. Bartholomew's Hospital for data cleaning and analysis. Data analysis was performed with SPSS version 25, including descriptive analysis of numeric (mean and range) and categorical values (total number and percentages) as well as p values when comparing different groups according timing for surgery (χ 2 test).
Ethical approval was obtained from each participating center after acceptance of the study protocol at the recruiting center (St. Bartholomew's Hospital). Individual patient consent was waived due the anonymised nature of the data.

| Service provision for emergency and urgent aortovascular conditions
A protocol to treat aortovascular pathologies was created at Barts Heart Centre on the 25 March 2020 and endorsed by the UK Aortic Surgery group and the Society of Cardiothoracic Surgery for Great Britain and Ireland (SCTS). [5][6][7][8] The protocol defines the cohort of aortovascular patients eligible for referral and treatment during the COVID-19 pandemic, triaged in several categories depending on the level of urgency at time of referral/presentation. • Level 3: Emergency-patients with acute aortic syndromes (type A aortic dissection, intramural hematoma, penetrating aortic ulcer, aortic transection, and acute complicated type B aortic dissection) and ruptured aneurysms of any anatomical location should be accepted and operated at the earliest opportunity, including outof-hours, due to the increased risk of mortality while waiting.

| Preoperative COVID-19 screening
On the 26 March 2020 a preoperative screening protocol for detection of SAVR-CoV-2 virus was intorudces at St. Bartholomew's Hospital after multidisciplinary review of available evidence an Public Health Guidance analysis. 3,9,10 It included a combination of two negative nasophayngeal swabs for polymerase change raction for ribonucleic acid (PCR-RNA) analysis, LOPEZ-MARCO ET AL.

| RESULTS
A total of 182 patients with aortovascular pathologies were operated from 1 March to 20 May 2020 in the 19 participating centers.
Mean age was 63 years (range 26-83 years), 33% of the patients were female and the mean EuroScore II was 9.6 (range 0.9-61.2).
The details of preoperative risk factors are listed in Table 1.
The acute aortic syndromes were categorized depending on antomical presentation and chronicity as follow: acute BeBakey I  days (30 min-53 days) and mean length of ITU stay was 4.7 days (30 min-53 days; Table 2).

T A B L E 1 Demographics and preoperative risks factors
In-hospital mortality was significantly higher, and almost exclusive, in patients presenting as emergency as opposed to elective procedures (p = .001). Other postoperative complications such as stroke, renal failure and haemofiltration and sternal wound infection were also significantly higher in the emergency group (p < .005;  One patient had signs of COVID-19 lung disease on the preoperative CT scan despite being asymptomatic and swab negative.

| Confirmed COVID-19 disease
He required reintubation and ventilation 7 days after surgery due chest infection and died of respiratory failure.
The last patient, mentioned earlier, was treated conservatively for acute DeBakey III aortic dissection and did not develop any COVID-19 related complications.

| Temporal and regional variation in delivery of aortovascular services
There was a clear temporal and regional variation on the delivery of aortovascular services.  (Figures 1 and 2).  (Table 3). Mortality due aortovascular conditions treated during this period was similar to national benchmarked results from pre-pandemic times 12   patients who would require respiratory and multiorgan support, as well a reallocation staff to those clinical areas.
Also, the increased anxiety of the general public after the declaration of the lockdown, led to a significant reduction of attendance to the hospitals, including the emergency services.
Compared with the prepandemic period national data for aortovascular procedures, it seems that the service provision for emergency aortovascular conditions has been protected during the early period of the COVID-19 pandemic and similar outcomes to pre-pandemic times have been achieved 13 (Table 3 and Figures 3-4).
Overall, the majority of individual centers have been able to maintain similar activity for emergency procedures compared with the prepandemic period, although certain regions more affected by the COVID-19 disease (i.e., Birmingham) have seen their ability to provide aortovascular cover canceled due to reallocation of the intensive care areas to treat respiratory patients ( Figure 2; Table 3).
The impact of not treating aortic diseases has been already reported and a risk of increased 6 months mortality has been recognized. 12 Therefore, the effect of suspension of elective surgery for patients on waiting lists will be appreciated in months to come.
The preoperative COVID-19 screening protocol, 9,10  With this strategy, we have observed a low in-hospital surgical mortality even for those who were diagnosed of COVID-19 during the peri-operative period.
F I G U R E 2 Temporal variation in the mortality of patients with aortovacular conditions treated in the participating centers in the UK over the COVID-19 pandemic period. The vertical green arrow marks the start of the lockdown situation in the UK. The blue line displays weekly mortality from aortovascular conditions compared to the the total number of aortovacualr conditions treated in the same period in the participating centers (orange line). Note that the mortality trend for aortovascular conditions was constant during the early months of the pandemic in the UK

HUMAN STUDIES
This study is registered as service evaluation project and therefore need for ethical approval was not required

CONFLICT OF INTERESTS
All the authors declare that there are no conflict of interests.  -19) in the UK displayed weekly (blue line) and the surgical aortovascular mortality during the same period of time in the study participating centers (orange line). The lines cross-over on the week of the 16 March 2020, corresponding with the start of the lockdown in the UK, when the number of COVID-19 cases started to increase exponentially and the Aortovascular activity decreased initially due to the reduced presentation to hospitals. Both curves reached a peak around mid of April to descend in a parallel way after that. Note that he scale for the COVID-19 mortality has been adapted and has to be multiplied ×100