The Diagnostic Value of Blood Next-Generation Sequencing in Early Surgical Site Infection After Spine Surgery

Figures & data

Table 1 Clinical Features of Patients Undergoing Spinal Surgery for Degenerative Diseases via the Posterior Approach

Characteristics		Infection (n=28)	Control (n=30)	Test Statistics	P
Age (years)		51.86±13.35	53.00±12.27	−0.350	0.726
Body mass index		27.71±2.88	27.86±2.93	−0.257	0.797
Sex (n)	Male	19	18	0.387	0.534
	Female	9	12
Smoking (n)	No	20	21	0.014	0.905
	Yes	8	9
Alcohol consumption (n)	No	19	23	0.563	0.453
	Yes	9	7
Immunosuppression (n)	No	26	27	–	0.533*
	Yes	2	3
Involved segment (n)	Cervical spine	1	2	0.293	0.864
	Thoracic spine	5	5
	Lumber spine	22	23
Internal fixation (n)	No	5	4	–	0.454*
	Yes	23	26
Allogeneic bone grafting (n)	No	25	25	–	0.393*
	Yes	3	5

Note: *Fisher’s exact test.

Table 2 Infection Features of Patients Undergoing Spinal Surgery for Degenerative Diseases via the Posterior Approach

Parameters		Infection (n=28)	Control (n=30)	Test Statistics	P
C-reactive protein (mg/L)		43.62±6.54	30.35±8.74	−4.987	<0.001
Erythrocyte sedimentation rate (mm/h)		51.57±17.91	40.03±18.77	−2.397	0.017
Procalcitonin (ng/mL)		0.47±0.39	0.34±0.10	−0.070	0.944
Intraoperative sample next-generation sequencing (n)	Positive	28	-
	Negative	0	-
Intraoperative sample bacterial culture (n)	Positive	25	-
	Negative	3	-
Infected bacteria (n)	Staphylococcus	12	-
	Streptococcus	5	-
	Enterococcus	6	-
	Escherichia	2	-
	Pseudomonas aeruginosa	2	-
	Salmonella	1	-

Table 3 Results of Next-Generation Sequencing and Bacterial Culture in Patients Undergoing Spinal Surgery for Degenerative Diseases via a Posterior Approach

Sample	Diagnostic Methods	Results	Infection (n=28)	Control (n=30)
Blood	Next-generation sequencing (n)	Positive	23 (82.1%)	1 (3.3%)
		Negative	5 (17.9%)	29 (96.7%)
	Bacterial culture (n)	Positive	7 (25.0%)	1 (3.3%)
		Negative	21 (75.0%)	29 (96.7%)
Incision drainage	Next-generation sequencing (n)	Positive	25 (89.3%)	18 (60.0%)
		Negative	3 (10.7%)	12 (40.0%)
	Bacterial culture (n)	Positive	17 (60.7%)	6 (20.0%)
		Negative	11 (39.3%)	24 (80.0%)

Table 4 Infection Diagnostic Value of Blood Next-Generation Sequencing in Patients Undergoing Spinal Surgery for Degenerative Diseases via a Posterior Approach and Who Suffered from Surgical Site Infection

Sample	Diagnostic Methods	Sensitivity	Specificity	Accuracy	Youden’s Index	Positive Predictive Value	Negative Predictive Value
Blood sample	Next-generation sequencing	0.82	0.97	0.90	0.79	0.96	0.85
	Bacterial culture	0.25	0.97	0.62	0.22	0.88	0.58
	Test statistics	12.500	<0.001	11.250		-	7.054
	P	<0.001	1.000	<0.001	-	0.444^#	0.008
Drainage fluid sample	Next-generation sequencing	0.89	0.40*	0.64*	0.29	0.58*	0.80
	Bacterial culture	0.61*	0.80	0.71	0.41	0.74	0.69
	Test statistics	6.125	8.643	0.409		1.611	0.231
	P	0.008	0.002	0.523	-	0.204	0.630

Notes: *Compared with the corresponding diagnostic method for blood samples, P<0.05. ^#Fisher’s exact test.