Splenectomy in patients with traumatic brain injury: Protective or harmful? A National Trauma Data Bank analysis

Clinical factors and outcomes of spleen-conserving surgery versus total splenectomy in splenic injuries: A nationwide database study

BACKGROUND

The objective of this study was to identify factors associated with the use of spleen-conserving surgeries, as well as patient outcomes, on a national scale.

METHODS

This retrospective cohort study (2010-2015) included patients (age≥16 years) with splenic injury in the National Trauma Data Bank. Patients who received a total splenectomy or a spleen-conserving surgery were compared for demographics and clinical outcomes.

RESULTS

During the study period, 18,425 received a total splenectomy and 1,825 received a spleen-conserving surgery. Total splenectomy was more likely to be performed for patients with age>65 (odds ratio [OR]: 0.63, p ​< ​0.001), systolic blood pressure<90 (OR: 0.63, p ​< ​0.001), heart rate>120 (OR: 0.83, p ​= ​0.007), and high-grade injuries (OR: 0.18, p ​< ​0.001). Penetrating trauma patients were more likely to undergo a spleen-conserving surgery (OR: 3.31, p ​< ​0.001). The use of spleen-conserving surgery was associated with a lower risk of pneumonia (OR: 0.79, p ​= ​0.009) and venous thromboembolism (OR: 0.72, p ​= ​0.006).

CONCLUSIONS

Spleen-conserving surgeries may be considered for patients with penetrating trauma, age<65, hemodynamic stability, and low-grade injuries. Spleen-conserving surgeries have decreased risk of pneumonia and venous thromboembolism.

Traumatic brain injury with concomitant injury to the spleen: characteristics and mortality of a high-risk trauma cohort from the TraumaRegister DGU®

PURPOSE

Based on the hypothesis that systemic inflammation contributes to secondary injury after initial traumatic brain injury (TBI), this study aims to describe the effect of splenectomy on mortality in trauma patients with TBI and splenic injury.

METHODS

A retrospective cohort analysis of patients prospectively registered into the TraumaRegister DGU® (TR-DGU) with TBI (AISHead ≥ 3) combined with injury to the spleen (AISSpleen ≥ 1) was conducted. Multivariable logistic regression modeling was performed to adjust for confounding factors and to assess the independent effect of splenectomy on in-hospital mortality.

RESULTS

The cohort consisted of 1114 patients out of which 328 (29.4%) had undergone early splenectomy. Patients with splenectomy demonstrated a higher Injury Severity Score (median: 34 vs. 44, p < 0.001) and lower Glasgow Coma Scale (median: 9 vs. 7, p = 0.014) upon admission. Splenectomized patients were more frequently hypotensive upon admission (19.8% vs. 38.0%, p < 0.001) and in need for blood transfusion (30.3% vs. 61.0%, p < 0.001). The mortality was 20.7% in the splenectomy group and 10.3% in the remaining cohort. After adjustment for confounding factors, early splenectomy was not found to exert a significant effect on in-hospital mortality (OR 1.29 (0.67-2.50), p = 0.45).

CONCLUSION

Trauma patients with TBI and spleen injury undergoing splenectomy demonstrate a more severe injury pattern, more compromised hemodynamic status and higher in-hospital mortality than patients without splenectomy. Adjustment for confounding factors reveals that the splenectomy procedure itself is not independently associated with survival.

Use of angioembolization in pediatric polytrauma patients: WITH BLUNT SPLENIC INJURYAngioembolization in Pediatric Blunt Splenic Injury

BACKGROUND/PURPOSE

We sought to analyze the use of angioembolization (AE) after pediatric splenic injuries at adult and pediatric trauma centers (ATCs/PTCs).

METHODS

The National Trauma Data Bank (2010-2015) was queried for patients (<18 years) who experienced blunt splenic trauma. Multivariate logistic regression was used to determine the association of AE with splenectomy. Propensity score matching was used to explore the relationship between trauma center designation and AE utilization.

RESULTS

14,027 encounters met inclusion criteria. 514 (3.7%) patients underwent AE. When compared to PTCs, patients were older, had a higher ISS, and more often presented in shock at ATCs (p<0.001 for all). Regression models demonstrated no difference in mortality between cohorts. Odds of splenectomy were lower for patients undergoing AE (OR 0.16 [CI: 0.08-0.31]), however this effect was mostly driven by utilization at ATCs. Using a 1:1 propensity score matching model, patients treated at ATCs were 4 times more likely to undergo AE and 7 times more likely to require a splenectomy compared to PTCs (p<0.001). Over 6 years, PTCs performed only 27 splenectomies and 23 AEs (1.1% and 0.9%, respectively).

CONCLUSIONS

AE was associated with improved splenic salvage at ATCs in select patients but appeared overutilized when compared to outcomes at PTCs. PTCs accomplished a higher splenic salvage rate with a lower AE utilization.

LEVEL OF EVIDENCE

III - Retrospective cohort study.

Risk factors associated with splenectomy following a blunt splenic injury in pediatric patients

PURPOSE

The purpose of the study was to identify the factors associated with splenectomy in pediatric trauma patients.

METHOD

Pediatric Trauma quality improvement program (P-TQIP) database calendar year 2014-2016 was accessed for the study. All patients, age ≤ 18 years old, who sustained splenic injury due to blunt mechanism, were included in the study. The primary outcome of the study was to identify the risk factors associated with splenectomy. Univariate followed by multivariate analyses were performed. A p value of < 0.05 was considered an indication of statistical significance.

RESULTS

Of 1297 trauma victims, who fulfilled the inclusion criteria, 57 (4.4%) patients underwent total splenectomy. In Univariate analysis, there were significant differences found, in many variables, between the groups who underwent splenectomy versus those who did not have splenectomy. A multivariate logistic regression analysis showed use of blood transfusion within 4 h and severity of splenic injury were the two variables associated with splenectomy. The area under the curve (AUC) value was 0.892 and the 95% confidence intervals were [0.859, 0.923].

CONCLUSION

Blood transfusion within 4 h of patient's arrival to the hospital and high-grade splenic injury were main factors for splenectomy in the pediatric population.

Post-TBI splenectomy may exacerbate coagulopathy and platelet activation in a murine model

INTRODUCTION

Traumatic brain injury (TBI) induces acute hypocoagulability, subacute hypercoagulability, and persistently elevated risk for thromboembolic events. Splenectomy is associated with increased mortality in patients with moderate or severe TBI. We hypothesized that the adverse effects of splenectomy in TBI patients may be secondary to the exacerbation of pathologic coagulation and platelet activation changes.

METHODS

An established murine weight-drop TBI model was utilized and a splenectomy was performed immediately following TBI. Sham as well as TBI and splenectomy alone mice were used as injury controls. Mice were sacrificed for blood draws at 1, 6, and 24 h, as well as 7 days post-TBI. Viscoelastic coagulation parameters were assessed by rotational thromboelastometry (ROTEM) and platelet activation was measured by expression of P-selectin via flow cytometry analysis of platelet rich plasma samples.

RESULTS

At 6 h following injury, TBI/splenectomy demonstrated hypocoagulability with prolonged clot formation time (CFT) compared to TBI alone. By 24 h following injury, TBI/splenectomy and splenectomy mice were hypercoagulable with a shorter CFT, a higher alpha angle, and increased MCF, despite a lower percentage of platelet contribution to clot compared to TBI alone. However, only the TBI/splenectomy continued to display this hypercoagulable state at 7 days. While TBI/splenectomy had greater P-selectin expression at 1-h post-injury, TBI alone had significantly greater P-selectin expression at 24 h post-injury compared to TBI/splenectomy. Interestingly, P-selectin expression remained elevated only in TBI/splenectomy at 7 days post-injury.

CONCLUSION

Splenectomy following TBI exacerbates changes in the post-injury coagulation state. The combination of TBI and splenectomy induces an acute hypocoagulable state that could contribute to an increase in intracranial bleeding. Subacutely, the addition of splenectomy to TBI exacerbates post-injury hypercoagulability and induces persistent platelet activation. These polytrauma effects on coagulation may contribute to the increased mortality observed in patients with combined brain and splenic injuries.

Systemic treatment with human amnion epithelial cells after experimental traumatic brain injury

Systemic administration of human amnion epithelial cells (hAECs) was recently shown to reduce neuropathology and improve functional recovery following ischemic stroke in both mice and marmosets. Given the significant neuropathological overlap between ischemic stroke and traumatic brain injury (TBI), we hypothesized that a similar hAEC treatment regime would also improve TBI outcomes. Male mice (12 weeks old, n ​= ​40) were given a sham injury or moderate severity TBI by controlled cortical impact. At 60 ​min post-injury, mice were given a single tail vein injection of either saline (vehicle) or 1 ​× ​10⁶ hAECs suspended in saline. At 24 ​h post-injury, mice were assessed for locomotion and anxiety using an open field, and sensorimotor ability using a rotarod. At 48 ​h post-injury, brains were collected for analysis of immune cells via flow cytometry, or histological evaluation of lesion volume and hAEC penetration. To assess the impact of TBI and hAECs on lymphoid organs, spleen and thymus weights were determined. Treatment with hAECs did not prevent TBI-induced sensorimotor deficits at 24 ​h post-injury. hAECs were detected in the injured brain parenchyma; however, lesion volume was not altered by hAEC treatment. Robust increases in several leukocyte populations in the ipsilateral hemisphere of TBI mice were found when compared to sham mice at 48 ​h post-injury; however, hAEC treatment did not alter brain immune cell numbers. Both TBI and hAEC treatment were found to increase spleen weight. Taken together, these findings indicate that-unlike in ischemic stroke-treatment with hAEC was unable to prevent immune cell infiltration and sensorimotor deficits in the acute stages following controlled cortical impact in mice. Although further investigations are required, our data suggests that the lack of hAEC-induced neuroprotection in the current study may be explained by the differential splenic contributions to neuropathology between these brain injury models.

Nonoperative Management of Blunt Splenic Trauma in Patients with Traumatic Brain Injury: Feasibility and Outcomes

INTRODUCTION

Preventing secondary insult to the brain is imperative following traumatic brain injury (TBI). Although TBI does not preclude nonoperative management (NOM) of splenic injuries, development of hypotension in this setting may be detrimental and could therefore lead trauma surgeons to a lower threshold for operative intervention and a potentially higher risk of failure of NOM (FNOM). We hypothesized that the presence of a TBI in patients with blunt splenic injury would lead to a higher risk of FNOM.

METHODS

Patients with blunt splenic injury were selected from the National Trauma Data Bank research datasets from 2007 to 2011. TBI was defined as AIS head ≥ 3 and FNOM as patients who underwent a spleen-related operation after 2 h from admission. TBI patients were compared to those without head injury. The primary outcome was FNOM.

RESULTS

Of 47,713 patients identified, 41,436 (86.8%) underwent a trial of NOM. FNOM was identical (10.6 vs. 10.8%, p = 0.601) among patients with and without TBI. TBI patients had lower adjusted odds for FNOM (AOR 0.66, p < 0.001), even among those with a high-grade splenic injury (AOR 0.68, p < 0.001). No difference in adjusted mortality was noted when comparing TBI patients with and without FNOM (AOR 1.01, p = 0.95).

CONCLUSIONS

NOM of blunt splenic trauma in TBI patients has higher adjusted odds for success. This could be related to interventions targeting prevention of secondary brain injury. Further studies are required to identify those specific practices that lead to a higher success rate of NOM of splenic trauma in TBI patients.

Association between pediatric blunt splenic injury volume and the splenectomy rate

BACKGROUND/PURPOSE

While pediatric trauma centers are shown to have lower splenectomy rate as compared to adult trauma centers, it remains unknown whether other institutional factors such as case volumes would have an impact on the splenectomy rate in pediatric blunt splenic injury (BSI).

METHODS

Pediatric patients who sustained BSI were identified from the National Trauma Data Bank 2007-2014. A hierarchical logistic regression model was built to evaluate differences in risk-adjusted splenectomy rate and in-hospital mortality in between trauma centers with different pediatric BSI case volumes.

RESULTS

A total of 7621 children who met criteria were treated at trauma centers with different pediatric BSI case volumes (0-60, 61-120, 121-180, 181-240 cases during 2007-2014 for Group 1, 2, 3, and 4, respectively). High volume centers were shown to have decreased splenectomy rates (odds ratios [OR] 0.50 and 0.64, 95% confidence intervals [CI] 0.30-0.83, 0.44-0.95 for Groups 3 and 4, respectively) with an additional survival benefit in Group 4 (OR 0.452, 95%CI 0.257-0.793) when compared to the lowest volume centers (Group 1).

CONCLUSIONS

Higher pediatric BSI case volume was associated with lower splenectomy rate with an additional survival benefit. Trauma centers' volume in pediatric BSI may be an important factor for the improved splenic preservation.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Early selenium treatment for traumatic brain injury: Does it improve survival and functional outcome?

BACKGROUND

Traumatic brain injury (TBI) is a major cause of death and debility following trauma. The initial brain tissue insult is worsened by secondary reactive responses including oxidative stress reactions, inflammatory changes and subsequent permanent neurologic deficits. Effective agents to improve functional outcome and survival following TBI are scarce. Selenium is an antioxidant which has shown to reduce oxidative stress. This study examines the effect of intravenous selenium (Selenase^®) treatment in patients with severe TBI on functional outcome and survival in a prospective study design.

METHODS

Patients sustaining TBI were prospectively identified during a 12-month period at an academic urban trauma center. Study inclusion criteria applied were: age ≥18 years, blunt injury mechanism and admission to neurosurgical intensive care unit (NICU). Early deaths (≤48h) and patients suffering extracranial injuries requiring invasive interventions or surgery were excluded. All consecutive admissions during a six-month period were administered intravenous Selenase^® for a maximum 10-day period and constituted cases. Patient demographics and outcomes up to six-months post-discharge were collected for analysis.

RESULTS

A total of 307 patients met inclusion criteria of which 125 were administered Selenase^®. Stepwise Poisson regression analysis identified five common predictors of poor functional outcome and in-hospital mortality: GCS ≤8, age ≥55 years, hypotension at admission, high Rotterdam score and invasive neurosurgical intervention. Selenase^® significantly reduced the risk of unfavourable functional outcomes, defined as GOS-E ≤4, at both discharge (adjusted RR 0.69, 95% CI 0.51-0.92, p=0.012) and at six months follow-up (adjusted RR 0.61, 95% CI 0.44-0.83, p=0.002). Following adjustment for significant group differences similar results were seen for functional outcome. Selenase^® did not improve survival (adjusted RR 1.12, 95% CI 0.62-2.02, p=0.709).

CONCLUSION

Intravenous Selenase^® treatment demonstrates a significant improvement in functional neurologic outcome. This effect is sustained at six months following discharge.

Overview of Traumatic Brain Injury: An Immunological Context

Traumatic brain injury (TBI) afflicts people of all ages and genders, and the severity of injury ranges from concussion/mild TBI to severe TBI. Across all spectrums, TBI has wide-ranging, and variable symptomology and outcomes. Treatment options are lacking for the early neuropathology associated with TBIs and for the chronic neuropathological and neurobehavioral deficits. Inflammation and neuroinflammation appear to be major mediators of TBI outcomes. These systems are being intensively studies using animal models and human translational studies, in the hopes of understanding the mechanisms of TBI, and developing therapeutic strategies to improve the outcomes of the millions of people impacted by TBIs each year. This manuscript provides an overview of the epidemiology and outcomes of TBI, and presents data obtained from animal and human studies focusing on an inflammatory and immunological context. Such a context is timely, as recent studies blur the traditional understanding of an “immune-privileged” central nervous system. In presenting the evidence for specific, adaptive immune response after TBI, it is hoped that future studies will be interpreted using a broader perspective that includes the contributions of the peripheral immune system, to central nervous system disorders, notably TBI and post-traumatic syndromes.

Reassessing mechanism as a predictor of pediatric injury mortality

BACKGROUND

The use of mechanism of injury as a predictor of injury outcome presents practical challenges because this variable may be missing or inaccurate in many databases. The purpose of this study was to determine the importance of mechanism of injury as a predictor of mortality among injured children.

METHODS

The records of children (<15-y-old) sustaining a blunt injury were obtained from the National Trauma Data Bank. Models predicting injury mortality were developed using mechanism of injury and injury coding using either abbreviated injury scale post-dot values (low-dimensional injury coding) or injury International Classification of Diseases, Ninth Revision codes and their two-way interactions (high-dimensional injury coding). Model performance with and without inclusion of mechanism of injury was compared for both coding schemes, and the relative importance of mechanism of injury as a variable in each model type was evaluated.

RESULTS

Among 62,569 records, a mortality rate of 0.9% was observed. Inclusion of mechanism of injury improved model performance when using low-dimensional injury coding but was associated with no improvement when using high-dimensional injury coding. Mechanism of injury contributed to 28% of model variance when using low-dimensional injury coding and <1% when high-dimensional injury coding was used.

CONCLUSIONS

Although mechanism of injury may be an important predictor of injury mortality among children sustaining blunt trauma, its importance as a predictor of mortality depends on the approach used for injury coding. Mechanism of injury is not an essential predictor of outcome after injury when coding schemes are used that better characterize injuries sustained after blunt pediatric trauma.