1. Definition of outcome measures (Yan 2014).

Types of outcome measures	Defined by	Including
Primary outcomes
Mortality	Dissection related and all causes	(Grade V) All deaths at 30 days and 12 months
Neurological deficit	Global events	(Grade I ‐ IV) Postoperative agitation, delirium, obtundation, or myoclonic movements, without localised cerebral neurological signs
	Focal events	(Grade I ‐ IV) Lateralising sensory or motor deficit or focal seizure activity
	Spinal neurological events	(Grade I ‐ IV) Paraplegia, paraparesis
Cardiac injury	Myocardial ischaemia	(Grade I ‐ IV)
	Low cardiac output syndrome	(Grade I ‐ IV)
	Arrhythmia	(Grade I ‐ IV)
	Pericardial effusion	(Grade I ‐ IV)
Respiratory compromise	Parenchymal complications	(Grade I ‐ IV) Atelectasis, pneumonia, pulmonary oedema, and acute respiratory distress syndrome
	Pleural complications	(Grade I ‐ IV) Pneumothorax, pleural effusion
Renal ischaemia	Modified RIFLE classification (Bellomo 2004): Risk (I), Injury (II), Failure (III), Loss/End‐Stage Kidney Dysfunction (IV)	(Grade I ‐ IV) Serum creatinine increase, glomerular filtration rate (GFR) decrease, anuria, haemodialysis
Secondary outcomes
False lumen thrombosis	Partial or complete thrombosis	‐
Mesenteric ischaemia	Gut complications	(Grade I ‐ IV) Ileus or gastric paresis, gut ischaemia manifested as metabolic acidosis or increased lactate
Grades as defined by Yan 2014: Grade I: any deviation from the normal postoperative course but self‐limiting or requiring simple therapeutic regimens (including antiemetics, antipyretics, analgesics, electrolytes, and physiotherapy); Grade II: complications requiring pharmacological treatment for resolution; Grade III: complications requiring surgical, endoscopic, or radiological intervention but not requiring regional or general anaesthesia or requiring interdisciplinary intervention; Grade IV: complications requiring surgical, endoscopic, or radiological intervention under regional or general anaesthesia, or requiring new intensive care unit (ICU) admission or ongoing ICU management for > 7 days or hospitalisation for > 30 days, or causing secondary organ failure; Grade V: death caused by a complication.