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

OBJECTIVE: To determine the diagnostic value of blood next-generation sequencing (NGS) in early surgical site infection after spine surgery. Because the blood is sterile in healthy individuals, it is expected that blood NGS is both sensitive and specific for the detection of infection. METHODS: A total of 28 patients with definitive spinal surgical site infections and controls (n=30) were retrospectively included. The postoperative results of NGS and culture on different samples, such as blood and drainage fluid, were obtained and compared to evaluate the diagnostic value of blood NGS. The diagnostic value parameters (sensitivity, specificity, etc.) were calculated. RESULTS: Among the four bacteriological exam methods, blood NGS was both sensitive and specific for the determination of infection after spine surgery. The sensitivities of blood and drainage fluid NGS were similar (0.82 vs 0.89, P=0.617). However, the specificities of the two assessments differed, which were 0.97 for blood NGS and 0.40 for drainage fluid NGS (P<0.001). The sensitivities of bacterial culture were lower than those of NGS (blood: 0.82 vs 0.25, P<0.001; drainage fluid: 0.89 vs 0.61, P<0.001), regardless of the sample type. However, the specificities of bacterial culture were equal to or higher than those of NGS (blood: 0.97 vs 0.97, P=1.000; drainage fluid: 0.40 vs 0.80, P=0.002). CONCLUSION: This article emphasizes the superiority of blood NGS in infection detection and bacterial determination in patients undergoing spine surgery. Compared with traditional drainage fluid bacterial culture and NGS, blood NGS was more sensitive and specific, and its extensive application could be expected.