Revenue - Schedule of Net Revenue by OCS Product and Country (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Net revenue	[1]	$ 30,262	$ 25,639
United States [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	[1]	21,861	19,239
All Other Countries [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	[1]	8,401	6,400
OCS Lung net revenue [Member]
Disaggregation Of Revenue [Line Items]
Net revenue		10,665	6,194
OCS Heart net revenue [Member]
Disaggregation Of Revenue [Line Items]
Net revenue		17,683	14,196
OCS Liver net revenue [Member]
Disaggregation Of Revenue [Line Items]
Net revenue		$ 1,914	$ 5,249

[1] Net revenue by country is categorized based on the location of the end customer