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.