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.
- 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.
- 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.
- 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.
- 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.