Discussion
HLT is widely accepted for certain
patients with advanced and refractory cardiopulmonary disease. From the
first surgery in 1968, more than 4000 HLTs have been performed to date.
Currently, the median survival is 6.5 years. Most HLTs are performed on
patients with severe pulmonary hypertension associated with congenital
heart disease, although there is a trend towards more HLT for
IIP.1
ECMO has been used as a BTT with a high risk of morbidity and mortality.
Even as waiting list mortality declined almost 40% after the
introduction of the Lung Allocation Score in 2005, annual waiting list
deaths in the United States reach almost 300, with fibrotic disease as
the leading cause.9 ECMO as a BTT in end-stage lung
disease has increased, but still only represents 1.5% of the total lung
transplantation volume. Otherwise, the outcomes of awake ambulatory ECMO
and spontaneous breathing can be excellent.4-8
Although the experience with ECMO
as a bridge to lung transplant is encouraging, there is limited evidence
to use ECMO as a bridge to HLT. A previous analysis by Sertic et al
reported a 50% mortality at 30 days and 50% mortality at 1 year in
patients with ECMO before HLT. ECMO was identified as
an strong predictor of
mortality.3
Femoral VA-ECMO support can be associated with deconditioning, muscle
wasting and diaphragmatic weakening secondary to the required bedrest
born out of concerns for bleeding or cannula dislodgement. Ambulation is
crucial to prevent complications, and early mobilization reduces
intensive care unit and overall hospital length of
stay.10-11Multiple studies have reported the feasibility and safety of ambulating
patients with femoral cannulas.10,12-13
Pasjira et al decribed 15 cases of ambulatory femoral VA-ECMO, just two
of them were a bridge to heart transplant. The ECMO cannulation and
ambulation protocol is very similar to ours, median time from
cannulation to out of bed was three days, time from cannulation to
ambulation was four days and the median distance walked on the last day
was 300 ft.10 Shudo et al reported a case of
ambulatory femoral VA-ECMO as bridge to HLT. The patient started to
ambulate after day 9 and could ambulate with minimal
assistance.12 Before ambulation, we performed a
careful evaluation of neurological, cardiovascular, respiratory,
musculoskeletal and hematologic (no bleeding) systems. Our patient was
out of bed on the first day post cannulation, and he increased
ambulation distance before transplant.