Table 1. Retrospective studies on paediatric ECMO and open lung biopsies.

Series	Sebire, 2005 [27]	Eulmesekian, 2005 [25]	Inwald, 2004 [23]	Tibbals, 2002 [26]	Cassidy, 2002 [22]	Ryan, 1998 [28]	Bond, 1996 [29]
Method	Retrospective study, UK	Retrospective study, single institution, UK	Retrospective study, single institution, UK	Retrospective study, single institution, Australia	Retrospective study, 4 ECMO centers, UK	Extracorporeal Life Organization Registry (ELSO)	Retrospective study, single institution, Kentucky
Period of time	7 years (1996-2003)	6 years (1997-2002)	6 years (1996-2002)	18 years (1982-2000)	3 years (1997-2000) 2,132,525 infants born in the UK	8 years (1986-1994)	6 years (1989-1995)
Ascertainment	children receiving ECMO in whom open lung biopsy was carried out	neonates with histological proven ACD/MVP and review of all ECMO and/or open lung biopsy cases	children referred for and placed on ECMO who also underwent open lung biopsy (before or during ECMO)	infants admitted to a paediatric intensive care with a diagnosis of PPHN	full term neonates with acute hypoxemic respiratory failure treated with ECMO	newborns who had open lung biopsies while receiving ECMO	all neonatal and paediatric patients who had an open lung biopsy while on ECMO
ECMO	22 children	9 neonates	506 referred and 310 patients placed on ECMO, of whom 136 neonates	13 neonates	173 neonates	6000 neonatal ECMO	213 patients
Open lung biopsy	12 neonates	10 neonates	15/506 patients 8/136 neonates	N/A	5/173 neonates	18/6000 neonates	8/213, of whom 4 neonates
Number of alveolar capillary dyplasia (ACD)	3/12 ACD	7 ACD	3/8 ACD	6/13 ACD	5/173 ACD	2/18 ACD	0/4 ACD
ACD mortality	N/A	7/7	3/3	6/6	5/5	2/2	N/A
Global mortality in the series	N/A	7/7	N/A	7/13 (54%)	36/173 (20%)	N/A	N/A
Premortem diagnosis of ACD	N/A	6/7	N/A	2/6	3/5	N/A	N/A
Autopsy rate	N/A	N/A	N/A	100% (7/7)	56%	N/A	N/A

PPHN= persistent pulmonary hypertension of the newborn, ECMO= extracorporeal membrane oxygenation, N/A= not available or not applicable