Aorto-vascular disease and COVID-19 at Liverpool Heart and Chest Hospital
Liverpool Heart and Chest Hospital (LHCH) is one of a very few centres in the UK offering medical and surgical services for patients with complex aorto-vascular diseases. The hospital is the only stand-alone Trust in the UK offering only cardiovascular and thoracic services and as such has no Emergency Department or Acute Medical Admissions facility. Four of fifteen cardiac surgeons specialise in aortovascular surgery with a separate emergency on-call rota. The team also work with local vascular surgeons under the banner of Liverpool Cardiovascular Surgery (LCS), with regular joint operating, commonly on hybrid cases. From 23rd March onward, the independent elective listing of patients for surgery by consultants was abandoned. General cardiac activity was wound down, under the direction of central government, to free up critical care capacity for potential transfer of COVID-19 patients from acute hospitals in the region. Activity was reduced from 5 cardiac theatres and 10 cases per day to 4 theatres and 4 cases per day, with only urgent patients allocated from a common pool. Aorto-vascular patients, urgent and emergency, had to compete with cardiac surgical patients for theatre space. All patients were discussed at t daily virtual “COVID-19 MDT” where an emphasis was placed on directing patients towards medical or minimally invasive therapy (endovascular) whenever possible. With time, a number of high-risk elective patients were operated.
Risk assessment of elective aortovascular patients
A major issue in this period was the quantification of post-operative COVID-19 infection in “clean” patients, thus balancing the additional risks of death from viral infection versus the risk of a putative delay in surgery – a delay of at least three months was presumed. For aorto-vascular disease the Vascular Society of Great Britain & Ireland (UK) offered guidance by increasing the size threshold for elective intervention for abdominal aortic aneurysm (AAA) to >7cm (18) as did the Society for Vascular Surgery in the United States, recommending intervention only on symptomatic thoraco-abdominal disease (19). The evidence base underlying this advice was opaque at best. We “RAG rated “(Red, Amber Green) and chose to operate on the so-called “Red urgent elective” patients with COVID screening and “clean hospital pathways”. The definition of Red was symptomatic severe disease. During this period, we made no adjustments to size-based guidelines.
Emergency aorto-vascular patients
There were unanimous recommendations from all advisory groups to treat emergency life threatening disease as normal while adopting appropriate safeguarding procedures for staff and other patients within the hospital.
Referral activity
A commonly observed phenomenon during this period was a dramatic reduction in both elective and urgent/emergency referrals thought to be due to very few patients presenting to hospital due to a fear of COVID-19 and local triage by referring doctors.
Outcomes of operated aorto-vascular patients
We examined our outcomes between the dates of 1/3/2020 and 4/7/2020. A total of 59 patients were operated (Table 1) during this period. In normal times we would expect the 4 aortovascular surgeons to perform roughly 1 elective/urgent case each per week over 42 weeks per year (i.e. total 56 cases) plus emergencies, suggesting our aortovascular activity was largely maintained during this 14-week period.
  1. Elective (Red on RAG rated)During this period, we performed operations on elective patients including root, arch, descending thoracic aorta (DTA) and thoraco-abdominal aortic aneurysm (TAAA) surgery including thoracic endovascular aortic repair (TEVAR). One of these elective patients turned COVID-19 positive in the post-operative period but did not develop COVID-19 pneumonia; the COVID-19 related mortality was zero.
  2. UrgentUrgent patients were those referred in from other hospitals and in-house patients requiring surgery during the same admission. Patients were screened for COVID-19 at referring hospitals and underwent CT screening and repeat COVID-19 swabs, lactic dehydrogenase (LDH) assay and lymphocyte measurements on transfer. We operated on 21 such patients. None developed COVID-19 but there were 3 deaths.
  3. EmergencyEmergency patients came into our unit from referring hospitals and were taken to theatre immediately with COVID-19 status unknown. We operated on nine such patients, two of whom developed COVID-19 in the post-operative course but not COVID-19 pneumonia. There was one non-COVID-19-related death.
  4. Medically managed patientsWe managed 15 aorto-vascular patients without surgery either because it was not indicated or because patients were unfit for the necessary surgical procedure. Eight were Type A dissections (moribund, 3; major stroke, 1; sub-acute, 1; or patient too frail/comorbid; 3). Five patients had surgically relevant thoraco-abdominal aortic dissection or aneurysm but were too frail/comorbid; one was an uncomplicated acute Type B (COVID-19 positive). One patient had a root abscess that was COVID positive and died while awaiting a negative swab prior to transfer.
No patient in this cohort died of post-operative COVID-19 pneumonia. It should be noted that our critical care area is divided into 4 distinct rooms, an arrangement that facilitated isolation of COVID-19 positive patients. During this period, we regularly admitted ventilated patients from neighbouring acute hospitals with community-acquired COVID-19. In summary, we attempted to maintain our aortovascular patients COVID-19-free via a combination of preoperative screening, strict theatre procedures, and separate pathways the “clean” and the COVID-19 cohort (Appendices 1-3).
It should be noted that our preoperative screening protocols changed as evidence presented itself. At the start of the lockdown period we performed routine CT scanning and bronchalveolar lavage (BAL) in theatre or when a patient returned to ITU. During late June 2020, we eventually abandoned CT scanning and a plain chest radiograph was used instead to identify individuals with early or suspected COVID pneumonia. In addition, it became clear the BAL was highly sensitive in the detection of viral RNA, but it was unclear whether this was simply dead virus indicating previous exposure or rather an active infection. Our experience showed that a positive BAL was of no consequence for the clinical course of the patient but created major issues for bed capacity with a need for isolation. For this reason and during late July, BAL was stopped in elective patients with a pre-operatively negative COVID-19 swab, normal chest x-ray and blood tests who had been isolating for two weeks.
We are thus only aware of one patient who should have undergone urgent surgery for a root abscess but died following delays, while awaiting his status to change from COVID-19 positive to negative. To our knowledge, no patients came to harm while on our waiting lists for delayed elective surgery. We see this as validation of the systems we developed to balance the need to make our critical care beds available for the national COVID-19 pandemic and the needs of our patients with life-threatening cardiovascular disease.
After this period, we gradually returned to normal work patterns, with surgeons planning their operating lists independently, progressively increasing elective activity as hospital pathways allowed. We still use a RAG rating system at present.