Perioperative mortality of metastatic spinal disease with unknown primary: A case report and review of literature

Table 2 Studies involving both spinal metastases of unknown primary tumors and perioperative mortality

No.	Ref.	Year	Period	Case, n	UPT, n (%)	Surgery indication	PC, n (%)	PM, n (%)
1	Morgen et al[33]	2013	2005-2010	2321	549 (23.7)	NA	NA	NA
2	Lee et al[17]	2014	2005-2010	200	5 (2.5)	Intractable pain	33 (16.5)	21 (10.5)
						Neurologic deficits
3	Quraishi et al[20]	2014	2004-2009	285	17 (6.0)	MSCC	67 (23.5)	NA
4	Fehlings et al[34]	2016	2008-2013	142	17 (12.0)	Intractable pain	42 (29.6)	13 (9.0)
						Neurologic deficits
						Spinal instability
5	Wänman et al[15]	2017	2003-2015	69	10 (14.5)	MSCC	15 (21.7)	NA
6	Ragel et al[16]	2017	2002-2010	45	4 (8.9)	NA	19 (42.0)	4 (8.9)
7	Tan et al[18]	2017	2012-2014	19	2 (10.5)	Intractable pain	3 (15.8)	1 (5.3)
						Neurologic deficits
8	Yang et al[19]	2017	2002-2014	39	1 (2.6)	Severe pain	5 (12.8)	1 (2.6)
						Neurologic deficits
						Fracture with displacement
						Failure of nonoperative treatment
						Histological diagnosis
9	Lau et al[29]	2017	2005-2011	97	10 (10.3)	Intractable pain	20 (20.6)	1 (1.0)
						Neurological deficit
						Spinal instability
10	Uei et al[35]	2018	2012-2015	55	1 (1.8)	Intractable pain	NA	3 (5.5)
						Neurologic deficits
						Spinal instability
						Radiation-resistant
11	Wright et al[6]	2018	1991-2016	1938	156 (8.0)	Symptomatic metastasis	NA	NA
12	Abdelbaky et al[36]	2018	2008-2013	70	10 (14.3)	Intractable pain	10 (14.3)	3 (4.3)
						Neurological deficit
						Histological diagnosis
						Spinal instability
						Radioresistant
13	Czigléczki et al[37]	2018	2008-2015	337	30 (8.9)	NA	135 (40.1)	26 (7.6)

MSCC: Metastatic spinal cord compression; NA: Not available; PC: Perioperative complication; PM: Perioperative mortality; UPT: Unknown primary tumor.