Duration of indwelling drain following instrumented posterolateral fusion of the lumbar spine does not predict surgical site infection requiring reoperation

The objective of this study was to determine the incidence and predictors of reoperation for surgical site infections (SSI) among patients whose lumbar, closed wound suction drains were removed in the inpatient setting prior to hospital discharge (pre-discharge cohort) versus after inpatient discharge during the first follow up visit (post-discharge cohort). All patients who were admitted for first-time, posterolateral decompression and fusion for degenerative lumbar spine disease were retrospectively reviewed at a single institution. In order to eliminate biases, neither the pre-discharge nor post-discharge cohorts experienced any intra-/postoperative sentinel events other than the primary outcome measure: reoperation for SSI. Of 209 patients in the pre-discharge (n = 130) and post-discharge (n = 79) cohorts, 15 patients required reoperation for SSI. Although time to drain discontinuation was significantly longer in the post-discharge (8.28 days) than the pre-discharge (4.65 days) cohorts (p < 0.001), the incidences of reoperation for SSI did not significantly differ (6.33 vs 7.69%, respectively, p = 0.711). In a multivariable regression, only smoking (OR = 5.75, p = 0.007) and depression (OR = 4.11, p = 0.040) predicted reoperation for SSI. Neither time to drain removal nor setting of drain removal was a predictor of reoperation for SSI. Although time to drain discontinuation was expectedly longer in the post-discharge versus pre-discharge cohorts, the incidences of reoperation for SSI did not significantly differ. Neither time to drain removal nor setting of drain removal predicted reoperation for SSI. These results suggest that patients may be safely discharged from the hospital with the surgical drain in place.