A comparison of computed tomography angiography and digital subtraction angiography for the diagnosis of penetrating cerebrovascular injury: a prospective multicenter study.

OBJECTIVE: In this research, the authors sought to characterize the incidence and extent of cerebrovascular lesions after penetrating brain injury in a civilian population and to compare the diagnostic value of head computed tomography angiography (CTA) and digital subtraction angiography (DSA) in their diagnosis. METHODS: This was a prospective multicenter cohort study of patients with penetrating brain injury due to any mechanism presenting at two academic medical centers over a 3-year period (May 2020 to May 2023). All patients underwent both CTA and DSA. The sensitivity and specificity of CTA was calculated, with DSA considered the gold standard. The number of DSA studies needed to identify a lesion requiring treatment that had not been identified on CTA was also calculated. RESULTS: A total of 73 patients were included in the study, 33 of whom had at least 1 penetrating cerebrovascular injury, for an incidence of 45.2%. The injuries included 13 pseudoaneurysms, 11 major arterial occlusions, 9 dural venous sinus occlusions, 8 dural arteriovenous fistulas, and 6 carotid cavernous fistulas. The sensitivity of CTA was 36.4%, and the specificity was 85.0%. Overall, 5.6 DSA studies were needed to identify a lesion requiring treatment that had not been identified with CTA. CONCLUSIONS: Cerebrovascular injury is common after penetrating brain injury, and CTA alone is insufficient to diagnosis these injuries. Patients with penetrating brain injuries should routinely undergo DSA.

Prognostication and Goals of Care Decisions in Severe Traumatic Brain Injury: A Survey of The Seattle International Severe Traumatic Brain Injury Consensus Conference Working Group.

Abstract Best practice guidelines have advanced severe traumatic brain injury (TBI) care; however, there is little that currently informs goals of care decisions and processes despite their importance and frequency. Panelists from the Seattle International severe traumatic Brain Injury Consensus Conference (SIBICC) participated in a survey consisting of 24 questions. Questions queried use of prognostic calculators, variability in and responsibility for goals of care decisions, and acceptability of neurological outcomes, as well as putative means of improving decisions that might limit care. A total of 97.6% of the 42 SIBICC panelists completed the survey. Responses to most questions were highly variable. Overall, panelists reported infrequent use of prognostic calculators, and observed variability in patient prognostication and goals of care decisions. They felt that it would be beneficial for physicians to improve consensus on what constitutes an acceptable neurological outcome as well as what chance of achieving that outcome is acceptable. Panelists felt that the public should help to define what constitutes a good outcome and expressed some support for a "nihilism guard." More than 50% of panelists felt that if it was certain to be permanent, a vegetative state or lower severe disability would justify a withdrawal of care decision, whereas 15% felt that upper severe disability justified such a decision. Whether conceptualizing an ideal or existing prognostic calculator to predict death or an unacceptable outcome, on average a 64-69% chance of a poor outcome was felt to justify treatment withdrawal. These results demonstrate important variability in goals of care decision making and a desire to reduce this variability. Our panel of recognized TBI experts opined on the neurological outcomes and chances of those outcomes that might prompt consideration of care withdrawal; however, imprecision of prognostication and existing prognostication tools is a significant impediment to standardizing the approach to care-limiting decisions.

Attitudes Toward Neurosurgery Education for the Nonneurosurgeon: A Survey Study and Critical Analysis of U.S. Military Training Techniques and Future Prospects.

BACKGROUND: The U.S. military requires medical readiness to support forward-deployed combat operations. Because time and distance to neurosurgical capabilities vary within the deployed trauma system, nonneurosurgeons are required to perform emergent cranial procedures in select cases. It is unclear whether these surgeons have sufficient training in these procedures. METHODS: This quality-improvement study involved a voluntary, anonymized specialty-specific survey of active-duty surgeons about their experience and attitudes toward U.S. military emergency neurosurgical training. RESULTS: Survey responses were received from 104 general surgeons and 26 neurosurgeons. Among general surgeons, 81% have deployed and 53% received training in emergency neurosurgical procedures before deployment. Only 16% of general surgeons reported participating in craniotomy/craniectomy procedures in the last year. Nine general surgeons reported performing an emergency neurosurgical procedure while on deployment/humanitarian mission, and 87% of respondents expressed interest in further predeployment emergency neurosurgery training. Among neurosurgeons, 81% had participated in training nonneurosurgeons and 73% believe that more comprehensive training for nonneurosurgeons before deployment is needed. General surgeons proposed lower procedure minimums for competency for external ventricular drain placement and craniotomy/craniectomy than did neurosurgeons. Only 37% of general surgeons had used mixed/augmented reality in any capacity previously; for combat procedures, most (90%) would prefer using synchronous supervision via high-fidelity video teleconferencing over mixed reality. CONCLUSIONS: These survey results show a gap in readiness for neurosurgical procedures for forward-deployed general surgeons. Capitalizing on capabilities such as mixed/augmented reality would be a force multiplier and a potential means of improving neurosurgical capabilities in the forward-deployed environments.

Transpacific Aeromedical Evacuation for a Ruptured Brain Arteriovenous Malformation During the COVID-19 Pandemic.

The COVID-19 pandemic has altered preexisting patient treatment algorithms and referral patterns, which has affected neurosurgical care worldwide. Brain arteriovenous malformations are complex vascular lesions that frequently present with intracerebral hemorrhage. Care for these patients is best performed at large medical centers by specialists with high volumes. The authors describe the care of a patient who presented in extremis to a resource-limited, community-sized military treatment facility (MTF) in Southeast Asia. In the MTF, the patient underwent emergent neurosurgical therapy. However, given newly implemented restrictions enacted to mitigate COVID-19 spread, local transfer for definitive care to a tertiary care facility was not possible. In order to attain definitive care for the patient, a transpacific aeromedical evacuation augmented with a critical care air transport team was utilized for transfer to a tertiary care, teaching hospital. This case demonstrates the safe treatment of a patient with hemorrhagic arteriovenous malformations and postoperative management under limited conditions in an MTF outside the CONUS. Given the unique circumstances and challenges the pandemic presented, the authors feel that this patient's outcome was only possible by leveraging all the capability military medicine has to offer.

Epidemiology of Blast Neurotrauma: A Meta-analysis of Blast Injury Patterns in the Military and Civilian Populations.

BACKGROUND: Mass casualty incidents (MCIs) due to bombing-related terrorism remain an omnipresent threat to our global society. The aim of this study was to elucidate differences in blast injury patterns between military and civilian victims affected by terrorist bombings. METHODS: An analysis of the Global Terrorism Database (GTD) and a PubMed literature search of casualty reports of bombing attacks from 2010-2020 was performed (main key words: blast injuries/therapy, terrorism, military personnel) with key epidemiological and injury pattern data extracted and statistically analyzed. RESULTS: Demographic analysis of casualties revealed that military casualties tend to be younger and predominantly male (P < 0.05) compared with civilians. Military casualties also reported higher amounts of head/neck injury (P < 0.01) compared with civilians. The proportion of instantaneous fatalities along with injuries affecting the thoracoabdominal and extremity regions remained approximately equal across both groups. CONCLUSIONS: Though the increased number of head/neck injuries was unexpected, we also found that the number of nonlethal head injuries also increased, predicating that more military blast neurotrauma patients survived their injuries. These data can be used to increase blast MCI preparation and education throughout the international neurosurgical community.

The changing landscape of military medical malpractice: from the Feres Doctrine to present.

Medical malpractice suits within the military have historically been limited by the Feres Doctrine, a legal precedent arising from a Supreme Court decision in 1950, which stated that active-duty personnel cannot bring suit for malpractice against either the United States government or military healthcare providers. This precedent has increasingly become a focus of discussion and reform as multiple cases claiming malpractice have been dismissed. Recently, however, the National Defense Authorization Act of 2020 initiated the first change to this precedent by creating an administrative body with the sole purpose of evaluating and settling claims of medical malpractice within the military's $50 billion healthcare system. This article seeks to present the legal history related to military malpractice and the Feres Doctrine as well as discuss the potential future implications that may arise as the Feres Doctrine is modified for the first time in 70 years.

An Endovascular Surgery Experience in Far-Forward Military Healthcare-A Case Series.

INTRODUCTION: The advancement of interventional neuroradiology has drastically altered the treatment of stroke and trauma patients. These advancements in first-world hospitals, however, have rarely reached far forward military hospitals due to limitations in expertise and equipment. In an established role III military hospital though, these life-saving procedures can become an important tool in trauma care. MATERIALS AND METHODS: We report a retrospective series of far-forward endovascular cases performed by 2 deployed dual-trained neurosurgeons at the role III hospital in Kandahar, Afghanistan during 2013 and 2017 as part of Operations Resolute Support and Enduring Freedom. RESULTS: A total of 15 patients were identified with ages ranging from 5 to 42 years old. Cases included 13 diagnostic cerebral angiograms, 2 extremity angiograms and interventions, 1 aortogram and pelvic angiogram, 1 bilateral embolization of internal iliac arteries, 1 lingual artery embolization, 1 administration of intra-arterial thrombolytic, and 2 mechanical thrombectomies for acute ischemic stroke. There were no complications from the procedures. Both embolizations resulted in hemorrhage control, and 1 of 2 stroke interventions resulted in the improvement of the NIH stroke scale. CONCLUSIONS: Interventional neuroradiology can fill an important role in military far forward care as these providers can treat both traumatic and atraumatic cerebral and extracranial vascular injuries. In addition, knowledge and skill with vascular access and general interventional radiology principles can be used to aid in other lifesaving interventions. As interventional equipment becomes more available and portable, this relatively young specialty can alter the treatment for servicemen and women who are injured downrange.

Paradoxical Contralateral Herniation Detected by Pupillometry in Acute Syndrome of the Trephined.

Severe traumatic brain injury has historically been a non-survivable injury. Recent advances in neurosurgical care, however, have demonstrated that these patients not only can survive, but they also can recover functionally when they undergo appropriate cerebral decompression within hours of injury. At the present, general surgeons are deployed further forward than neurosurgeons (Role 2 compared to Role 3) and have been provided with guidelines that stipulate conditions where they may have to perform decompressive craniectomies. Unfortunately, Role 2 medical facilities do not have access to computed tomography imaging or intracranial pressure monitoring capabilities rendering the decision to proceed with craniectomy based solely on exam findings. Utilizing a case transferred from downrange to our institution, we demonstrate the utility of a small, highly portable quantitative pupillometer to obtain reliable and reproducible data about a patient's intracranial pressures. Following the case presentation, the literature supporting quantitative pupillometry for surgical decision-making is reviewed.

Survival after traumatic brain injury improves with deployment of neurosurgeons: a comparison of US and UK military treatment facilities during the Iraq and Afghanistan conflicts.

INTRODUCTION: Traumatic brain injury (TBI) is the most common cause of death on the modern battlefield. In recent conflicts in Iraq and Afghanistan, the US typically deployed neurosurgeons to medical treatment facilities (MTFs), while the UK did not. Our aim was to compare the incidence, TBI and treatment in US and UK-led military MTF to ascertain if differences in deployed trauma systems affected outcomes. METHODS: The US and UK Combat Trauma Registries were scrutinised for patients with HI at deployed MTFs between March 2003 and October 2011. Registry datasets were adapted to stratify TBI using the Mayo Classification System for Traumatic Brain Injury Severity. An adjusted multiple logistic regression model was performed using fatality as the binomial dependent variable and treatment in a US-MTF or UK-MTF, surgical decompression, US military casualty and surgery performed by a neurosurgeon as independent variables. RESULTS: 15 031 patients arrived alive at military MTF after TBI. Presence of a neurosurgeon was associated with increased odds of survival in casualties with moderate or severe TBI (p<0.0001, OR 2.71, 95% CI 2.34 to 4.73). High injury severity (Injury Severity Scores 25-75) was significantly associated with a lower survival (OR 4×104, 95% CI 1.61×104 to 110.6×104, p<0.001); however, having a neurosurgeon present still remained significantly positively associated with survival (OR 3.25, 95% CI 2.71 to 3.91, p<0.001). CONCLUSIONS: Presence of neurosurgeons increased the likelihood of survival after TBI. We therefore recommend that the UK should deploy neurosurgeons to forward military MTF whenever possible in line with their US counterparts.

United States Military Service Members Demonstrate Substantial and Heterogeneous Long-Term Neuropsychological Dysfunction after Moderate, Severe, and Penetrating Traumatic Brain Injury.

The objective of the study was to examine long-term neuropsychological outcome after moderate, severe, and penetrating traumatic brain injury (TBI) in U.S. military service members and veterans (SMVs). Eighty-five SMVs with a history of moderate (n = 18), severe (n = 17), or penetrating (n = 26) TBI, or an injury without TBI (i.e., trauma control [TC], n = 24) were assessed five or more years (mean = 69.4 months; standard deviation = 35.6) post-injury. All passed performance validity tests. Participants completed a battery of neurocognitive tests and a personality inventory. Five cognitive domain composites, each composed of four test scores, and an overall test battery mean (OTBM) were computed. The penetrating TBI group performed worse than the TC group and/or the moderate TBI group on most cognitive domains and the OTBM. The severe TBI group also performed worse than the TC group and moderate TBI group on processing speed and the OTBM, and worse than the TC group on attention/working memory. Just more than half of participants with severe (56%) or penetrating (64%) TBI met criteria for mild neurocognitive disorder, with processing speed the most commonly impaired domain. In addition, 80% of TBI participants had one or more clinically elevated scales on the Minnesota Multiphasic Personality Inventory-2-Restructured Form® (MMPI-2-RF), with somatic complaints the most common elevation. In conclusion, there was significantly reduced cognitive and psychological functioning many years after severe and penetrating TBI in SMVs. Cognitive and psychological dysfunction, however, were highly variable, with a substantial minority of SMVs having good outcome. Long-term individualized support is necessary for individuals after moderate, severe, and penetrating TBI.

Protocolization of Post-Transforaminal Lumbar Interbody Fusion Pain Control with Elimination of Benzodiazepines and Long-Acting Opioids.

BACKGROUND: The opioid epidemic continues to worsen with a concomitant increase in opioid-related mortality. In response, the Department of Defense and Veterans Health Agency recommended against the use of long-acting opioids (LAOs) and concurrent use of opioids with benzodiazepines. Subsequently, we eliminated benzodiazepines and LAOs from our postoperative pain control regimen. OBJECTIVE: To evaluate the impact of removing benzodiazepines and LAOs on postoperative pain in single-level transforaminal lumbar interbody fusion (TLIF) patients. METHODS: A retrospective cohort study of single-level TLIF patients from February 2016-March 2018 was performed. Postoperative pain control in the + benzodiazepine cohort included scheduled diazepam with or without LAOs. These medications were replaced with nonbenzodiazepine, opioid-sparing adjuncts in the -benzodiazepine cohort. Pain scores, length of hospitalization, trigger medication use, and opioid use and duration were compared. RESULTS: Among 77 patients, there was no difference between inpatient pain scores, but the -benzodiazepine cohort experienced a faster rate of morphine equivalent reduction (-18.7%, 95% CI [-1.22%, -36.10%]), used less trigger medications (-1.55, 95% CI [-0.43, -2.67]), and discharged earlier (0.6 d; 95% CI [0.01, 1.11 d]). As outpatients, the -benzodiazepine cohort was less likely to receive opioid refills at 2 wk (29.2% vs 55.8%, P = .021) and 6 mo postoperatively (0% vs 13.2%, P = .039), and was less likely to be using opioids by 3 mo postoperatively (13.3% vs 34.2%, P = .048). CONCLUSION: Replacement of benzodiazepines and LAOs in the pain control regimen for single-level TLIFs did not affect pain scores and was associated with decreased opioid use, a reduction in trigger medications, and shorter hospitalizations.

The Silver Lining: Advances in the Surgical Management of Brain Trauma Attributable to War.

Within the text we elaborate on the relationship between war and medicine, particularly as it pertains to neurosurgery and the management of brain trauma, and emphasize neurosurgical advancements in the treatment of brain trauma gleaned from U.S.-involved conflicts of the 21st century.

Exposure to Blast Overpressure Impairs Cerebral Microvascular Responses and Alters Vascular and Astrocytic Structure.

Exposure to blast overpressure may result in cerebrovascular impairment, including cerebral vasospasm. The mechanisms contributing to this vascular response are unclear. The aim of this study was to evaluate the relationship between blast and functional alterations of the cerebral microcirculation and to investigate potential underlying changes in vascular microstructure. Cerebrovascular responses were assessed in sham- and blast-exposed male rats at multiple time points from 2 h through 28 days after a single 130-kPa (18.9-psi) exposure. Pial microcirculation was assessed through a cranial window created in the parietal bone of anesthetized rats. Pial arteriolar reactivity was evaluated in vivo using hypercapnia, barium chloride, and serotonin. We found that exposure to blast leads to impairment of arteriolar reactivity >24 h after blast exposure, suggesting delayed injury mechanisms that are not simply attributed to direct mechanical deformation. Observed vascular impairment included a reduction in hypercapnia-induced vasodilation, increase in barium-induced constriction, and reversal of the serotonin effect from constriction to dilation. A reduction in vascular smooth muscle contractile proteins consistent with vascular wall proliferation was observed, as well as delayed reduction in nitric oxide synthase and increase in endothelin-1 B receptors, mainly in astrocytes. Collectively, the data show that exposure to blast results in delayed and prolonged alterations in cerebrovascular reactivity that are associated with changes in the microarchitecture of the vessel wall and astrocytes. These changes may contribute to long-term pathologies involving dysfunction of the neurovascular unit, including cerebral vasospasm.

Inadequate Decompressive Craniectomy Following a Wartime Traumatic Brain Injury - An Illustrative Case of Why Size Matters.

Traumatic brain injury has been called the "signature injury" of the wars in Iraq and Afghanistan, and the management of severe and penetrating brain injury has evolved considerably based on the experiences of military neurosurgeons. Current guidelines recommend that decompressive hemicraniectomy be performed with large, frontotemporoparietal bone flaps, but practice patterns vary markedly. The following case is illustrative of potential clinical courses, complications, and efforts to salvage inadequately-sized decompressive craniectomies performed for combat-related severe and penetrating brain injury. The authors follow this with a review of the current literature pertaining to decompressive craniectomy, and finally provide their recommendations for some of the technical nuances of performing decompressive hemicraniectomy after severe or penetrating brain injury.

Two-year mortality and functional outcomes in combat-related penetrating brain injury: battlefield through rehabilitation.

OBJECTIVEThere are limited data concerning the long-term functional outcomes of patients with penetrating brain injury. Reports from civilian cohorts are small because of the high reported mortality rates (as high as 90%). Data from military populations suggest a better prognosis for penetrating brain injury, but previous reports are hampered by analyses that exclude the point of injury. The purpose of this study was to provide a description of the long-term functional outcomes of those who sustain a combat-related penetrating brain injury (from the initial point of injury to 24 months afterward).METHODSThis study is a retrospective review of cases of penetrating brain injury in patients who presented to the Role 3 Multinational Medical Unit at Kandahar Airfield, Afghanistan, from January 2010 to March 2013. The primary outcome of interest was Glasgow Outcome Scale (GOS) score at 6, 12, and 24 months from date of injury.RESULTSA total of 908 cases required neurosurgical consultation during the study period, and 80 of these cases involved US service members with penetrating brain injury. The mean admission Glasgow Coma Scale (GCS) score was 8.5 (SD 5.56), and the mean admission Injury Severity Score (ISS) was 26.6 (SD 10.2). The GOS score for the cohort trended toward improvement at each time point (3.6 at 6 months, 3.96 at 24 months, p > 0.05). In subgroup analysis, admission GCS score ≤ 5, gunshot wound as the injury mechanism, admission ISS ≥ 26, and brain herniation on admission CT head were all associated with worse GOS scores at all time points. Excluding those who died, functional improvement occurred regardless of admission GCS score (p < 0.05). The overall mortality rate for the cohort was 21%.CONCLUSIONSGood functional outcomes were achieved in this population of severe penetrating brain injury in those who survived their initial resuscitation. The mortality rate was lower than observed in civilian cohorts.

Catastrophic Non-Survivable Brain Injury Care-Role 2/3.

A catastrophic brain injury is defined as any brain injury that is expected to result in permanent loss of all brain function above the brain stem level. These clinical recommendations will help stabilize the patient so that they may be safely evacuated from theater. In addition to cardiovascular and hemodynamic goals, special attention must be paid to their endocrine dysfunction and its treatment-specifically steroid, insulin and thyroxin (t4) replacement while evaluating for and treating diabetes insipidus. Determining the futility of care coupled with resource management must also be made at each echelon. Logistical coordination and communication is paramount to expedite these patients to higher levels of care so that there is an increased probability of reuniting them with their family.

Neurosurgical workload during US combat operations: 2002 to 2016.

BACKGROUND: Approximately 4.5% of surgical procedures performed at Role 2 (R2) (forward surgical) and Role 3 (R3) (theater) medical treatment facilities can be classified as neurosurgical. These procedures are foreign to the routine daily practice of the military general surgeon. The purpose of this study was to examine the neurosurgical workload in Iraq and Afghanistan in order to inform the future predeployment neurosurgical training needs of nonneurosurgical providers. METHODS: Retrospective analysis of the Department of Defense Trauma Registry for all R2 and R3 medical facilities, from January 2002 to May 2016. The 103 neurosurgical International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes identified were grouped by anatomic location. Select groups were further subdivided. Data analysis used Stata version 14 (College Station, TX). RESULTS: A total of 7,509 neurosurgical procedures were identified. The majority (7,244 [96.5%]) occurred at R3 theater hospitals. Cranial procedures were the most common at both R2 (120, 45.3%) and R3 (4,483 [61.9%]), with craniotomy/craniectomy the most frequent procedure. Spine procedures were performed almost exclusively at R3, with 61.1% being fusions/stabilizations and 26.9% being spinal decompression alone. Neurosurgical caseload was variable over the 15-year study period, dropping to almost zero in 2016. CONCLUSIONS: Neurosurgical procedures were performed primarily at larger R3 theater hospitals where neurosurgeons were assigned if present in theater; however, more than 100 cranial procedures were performed at forward R2 where neurosurgeons were not deployed. Considering that neurosurgeons are not everywhere available within the war zone, deploying general surgeons should have familiarity with trauma neurosurgery. LEVEL OF EVIDENCE: Epidemiologic study, level III; Care Management, level IV.