Does minimally invasive spine surgery reduce surgical site infection rates in the trauma patient? A Southeast Asian experience.

Introduction: The trauma patient has an increased susceptibility to postoperative surgical site infection (SSI). There is a lack of studies in the literature investigating the rates of SSI in minimally invasive spine (MIS) surgery for trauma patients with associated injuries, who also require surgical intervention for thoracolumbar fractures. We aim to investigate if MIS surgery for trauma patients reduces the incidence of SSI through a less invasive approach and smaller surgical incision. Methods: A case series of 30 trauma patients who underwent MIS surgery for thoracolumbar spine fractures at our center were followed up for a year. The primary outcome measured was the presence of a postoperative SSI. Subgroup analysis was performed to determine if there were specific factors that increase the risk of developing a SSI. Results: In total, 4 (13%) patients developed postoperative SSI out of which 1 was a deep infection (3%). Subgroup analysis of both patient and surgical factors did not demonstrate statistically significant results to suggest risk factors for SSI post-MIS surgery in our patient group. Conclusion: Our series of patients did not reflect a lower incidence of SSI with MIS surgery compared to incidences in the literature. This may suggest that the increased rates of SSI in the trauma patient may not be best addressed by a minimally invasive approach alone. A multidisciplinary approach that addresses other factors - such as prolonged recumbence and a compromised immunological state may yield improved results.

Impact of time to resumption of antithrombotic therapy on outcomes after surgical evacuation of chronic subdural hematoma: A multicenter cohort study.

BACKGROUND: The decision to resume antithrombotic therapy after surgical evacuation of chronic subdural hematoma (CSDH) requires judicious weighing of the risk of bleeding against that of thromboembolism. This study aimed to investigate the impact of time to resumption of antithrombotic therapy on outcomes of patients after CSDH drainage. METHODS: Data were obtained retrospectively from three tertiary hospitals in Singapore from 2010 to 2017. Outcome measures analyzed were CSDH recurrence and any thromboembolic events. Logistic and Cox regression tests were used to identify associations between time to resumption and outcomes. RESULTS: A total of 621 patients underwent 761 CSDH surgeries. Preoperative antithrombotic therapy was used in 139 patients. 110 (79.1%) were on antiplatelets and 35 (25.2%) were on anticoagulants, with six patients (4.3%) being on both antiplatelet and anticoagulant therapy. Antithrombotic therapy was resumed in 84 patients (60.4%) after the surgery. Median time to resumption was 71 days (IQR 29 - 201). Recurrence requiring reoperation occurred in 15 patients (10.8%), of which 12 had recurrence before and three after resumption. Median time to recurrence was 35 days (IQR 27 - 47, range 4 - 82 days). Recurrence rates were similar between patients that were restarted on antithrombotic therapy before and after 14, 21, 28, 42, 56, 70 and 84 days, respectively. Thromboembolic events occurred in 12 patients (8.6%), of which five had the event prior to restarting antithrombosis. CONCLUSIONS: Time to antithrombotic resumption did not significantly affect CSDH recurrence. Early resumption of antithrombotic therapy can be safe for patients with a high thromboembolic risk.

Neuromonitoring in Cervical Spine Surgery: When Is a Signal Drop Clinically Significant?

STUDY DESIGN: Retrospective cohort study. PURPOSE: To identify the clinical significance of different patterns of intraoperative neuromonitoring (IONM) signal alerts. OVERVIEW OF LITERATURE: IONM is a long-established valuable adjunct to complex spine surgeries. IONM for cervical spine surgery is in the form of somatosensory evoked potential (SSEP) and motor evoked potential (MEP). The efficacy of both modalities (individually or in combination) to detect clinically significant neurological compromise is constantly being debated and requires conclusive suggestions. METHODS: Clinical and neuromonitoring data of 207 consecutive adult patients who underwent cervical spine surgeries at multiple surgical centers using bimodal IONM were analyzed. Signal changes were divided into three groups. Group 0 had transient signal changes in either MEPs or SSEPs, group 1 had sustained unimodal changes, and group 2 had sustained changes in both MEPs and SSEPs. The incidences of true neurological deficits in each group were recorded. RESULTS: A total of 25% (52/207) had IONM signal alerts. Out of these signal drops, 96% (50/52) were considered to be false positives. Groups 0 and 1 had no incidence of neurological deficits, while group 2 had a 29% (2/7) rate of true neurological deficits. The sensitivities of both MEP and SSEP were 100%. SSEP had a specificity of 96.6%, while MEP had a lower specificity at 76.6%. C5 palsy rate was 6%, and there was no correlation with IONM signal alerts (p=0.73). CONCLUSIONS: This study shows that we can better predict its clinical significance by dividing IONM signal drops into three groups. A sustained, bimodal (MEP and SSEP) signal drop had the highest risk of true neurological deficits and warrants a high level of caution. There were no clear risk factors for false-positive alerts but there was a trend toward patients with cervical myelopathy.

Development of a prognostic scoring system to predict risk of reoperation for contralateral hematoma growth after unilateral evacuation of bilateral chronic subdural hematoma.

Bilateral chronic subdural hematoma (bCSDH) is frequently drained unilaterally when the contralateral CSDH is small and asymptomatic. However, reoperation rates for contralateral CSDH growth can be high. We aimed to develop a prognostic scoring system to guide the selection of suitable patients for unilateral drainage of bCSDH. Data were collected retrospectively across three tertiary hospitals from 2010 to 2017 on all consecutive bCSDH patients aged 21 or above. Predictors of reoperation were identified using multivariable logistic regression. A prognostic score was developed and internally validated. 240 bCSDH patients were analyzed. 98 (40.8%) underwent unilateral and 142 (59.2%) underwent bilateral evacuation. Clinical outcomes were comparable between the unilateral and bilateral evacuation groups. Within the unilateral evacuation group, 4 (4.1%) had a reoperation for contralateral CSDH growth. Reoperation for contralateral CSDH was predicted by preoperative use of anticoagulants (OR = 15.0, 95% CI: 1.49-169.15, p = 0.017). Complete resolution of contralateral CSDH was predicted by its preoperative maximum width, with a cut-off of 9 mm producing the highest sensitivity and specificity (OR = 4.17 for ≤9 mm, 95% CI: 1.54-11.11, p = 0.004). Using our prognostic score, reoperation rate for contralateral CSDH was 1.6%, 3.6%, 16.7%, and 50.0% in low-risk, moderate-risk, high-risk and very high-risk patients, respectively. With each increase of 1 in the prognostic score, patients were 4 times as likely to undergo reoperation for contralateral CSDH (OR = 3.98, 95% CI: 1.36-13.53, p = 0.013). Our proposed risk score may be used as an adjunct in clinical decision making for bCSDH patients undergoing unilateral evacuation.

Outcomes of Subdural Versus Subperiosteal Drain After Burr-Hole Evacuation of Chronic Subdural Hematoma: A Multicenter Cohort Study.

BACKGROUND: Although the use of a postoperative drain after burr-hole evacuation of chronic subdural hematoma (CSDH) is known to improve surgical outcomes, the superiority of subdural over subperiosteal drains has not been firmly established. Evidence comparing these 2 drain types is largely restricted to single-center series with limited numbers. Using a multicenter cohort study, we aimed to show noninferiority of subperiosteal drains vis-à-vis subdural drains after burr-hole evacuation of CSDH. METHODS: We performed a retrospective analysis of all consecutive patients with CSDH aged 21 years and older who had undergone burr-hole craniostomy across 3 tertiary hospitals from 2010 to 2017. Primary outcome measures included CSDH recurrence and modified Rankin Scale (mRS) score at 6 months. Outcomes of patients in the subdural and subperiosteal drain groups were analyzed and confounders were adjusted for using multivariate logistic regression. RESULTS: Of the 570 cases analyzed, 329 (57.7%) received a subdural drain and 241 (42.3%) received a subperiosteal drain. There was no significant difference between the 2 drain groups in CSDH recurrence (13.1% in the subdural group vs. 11.2% in the subperiosteal group; P = 0.502) or 6-month mRS score (27.2% with mRS 4-6 in the subdural group vs. 20.4% in the subperiosteal group; P = 0.188). Independent predictors of CSDH recurrence identified on multivariate analysis included premorbid mRS score 0-3 (P = 0.021), separated CSDH type on preoperative computed tomography scan (P = 0.002), and postoperative pneumocephalus of ≥15 mm (P = 0.005). CONCLUSIONS: Outcomes of subdural and subperiosteal drains after burr-hole craniostomy for CSDH are largely equivalent based on our findings.