Postoperative spine surgical site infections: high rate of failure of one-stage irrigation and debridement

Abstract

Background context: Following spine surgery, postoperative surgical site infection (SSI) is a rare but potentially devastating complication. Previous studies have assessed risk factors for spine SSI and one aimed to develop risk stratification tool to assess management options, but this tool has not been externally validated or regularly used.

Purpose: The current study aimed to investigate the rate of SSI following elective spine surgery, surgical management pursued, and success of traditionally utilized one-stage of irrigation and debridement (I&D) with closure over drains.

Study design: Retrospective case-control study.

Patient sample: Adult, elective spine surgeries performed at a single academic institution between 2013 and 2021 were evaluated. Patients who developed SSI requiring surgical intervention were identified.

Outcome measures: Those who underwent initial management with I&D and closure over drains were assessed for need of subsequent I&D (considered failure of initial infection management).

Methods: Of spine surgeries meeting inclusion criteria, those with SSI were identified and management was characterized. For those who did and did not fail attempted one stage I&D with closure over drains, pre-operative and surgical variables from the index procedure as well as infection characteristics were assessed and compared with univariable and multivariable analyses.

Results: Of 11,023 elective spine surgeries, SSI was identified for 76 (0.7%). For initial management, I&D with closure over drains was used for 66 (86.8%) while I&D and wound vacuum management was used 10 (13.2%). Failure of attempted one stage I&D (requiring subsequent I&D procedure) was identified for 18 (27% of those undergoing I&D and closure over drains). Of multiple patient, surgical, and infection characteristics, the only factor identified as independently predictive of one stage I&D failure was presence of bacteremia (odds ratio [OR] 38.3, p=0.0007). Within the sub-cohort of patients with bacteremia, failure of attempted one stage I&D was noted for 80%.

Conclusion: Less than one percent of a large cohort of patients undergoing spine surgery were found to develop SSIs. Of those undergoing attempted one stage I&D, most patient, surgical, and infection variables did not influence outcome of the intervention. However, those with bacteremia were at 38.3 times greater odds of failing attempted one-stage I&D. These results suggest considering delayed closure approaches in these cases.

Keywords: Clinical outcomes; Complications; Infection; Infection management; Post-operative complications; Surgical site infection.