Brain Oxygen-Directed Management of Aneurysmal Subarachnoid Hemorrhage. Temporal Patterns of Cerebral Ischemia During Acute Brain Attack, Early Brain Injury, and Territorial Sonographic Vasospasm.

BACKGROUND: Neurocritical management of aneurysmal subarachnoid hemorrhage focuses on delayed cerebral ischemia (DCI) after aneurysm repair. METHODS: This study conceptualizes the pathophysiology of cerebral ischemia and its management using a brain oxygen-directed protocol (intracranial pressure [ICP] control, eubaric hyperoxia, hemodynamic therapy, arterial vasodilation, and neuroprotection) in patients with subarachnoid hemorrhage, undergoing aneurysm clipping (n = 40). RESULTS: The brain oxygen-directed protocol reduced Lbo2 (Pbto2 [partial pressure of brain tissue oxygen] <20 mm Hg) from 67% to 15% during acute brain attack (<24 hours of ictus), by increasing Pbto2 from 11.31 ± 9.34 to 27.85 ± 6.76 (P < 0.0001) and then to 29.09 ± 17.88 within 72 hours. Day-after-bleed, Fio2 change, ICP, hemoglobin, and oxygen saturation were predictors for Pbto2 during early brain injury. Transcranial Doppler ultrasonography velocities (>20 cm/second) increased at day 2. During DCI caused by territorial sonographic vasospasm (TSV), middle cerebral artery mean velocity (Vm) increased from 45.00 ± 15.12 to 80.37 ± 38.33/second by day 4 with concomitant Pbto2 reduction from 29.09 ± 17.88 to 22.66 ± 8.19. Peak TSV (days 7-12) coincided with decline in Pbto2. Nicardipine mitigated Lbo2 during peak TSV, in contrast to nimodipine, with survival benefit (P < 0.01). Intravenous and cisternal nicardipine combination had survival benefit (Cramer Φ = 0.43 and 0.327; G2 = 28.32; P < 0.001). This study identifies 4 zones of Lbo2 during survival benefit (Cramer Φ = 0.43 and 0.3) TSV, uncompensated; global cerebral ischemia, compensated, and normal Pbto2. Admission Glasgow Coma Scale score (not increased ICP) was predictive of low Pbto2 (ß = 0.812, R2 = 0.661, F1,30 = 58.41; P < 0.0001) during early brain injury. Coma was the only credible predictor for mortality (odds ratio, 7.33/>4.8∗; χ2 = 7.556; confidence interval, 1.70-31.54; P < 0.01) followed by basilar aneurysm, poor grade, high ICP and Lbo2 during TSV. Global cerebral ischemia occurs immediately after the ictus, persisting in 30% of patients despite the high therapeutic intensity level, superimposed by DCI during TSV. CONCLUSIONS: We propose implications for clinical practice and patient management to minimize cerebral ischemia.

Creation of false pedicles and a neo-pelvis for lumbopelvic reconstruction following en bloc resection of an iliosacral chondrosarcoma with lumbar spine extension: technical note.

En bloc resection with negative tumor margins remains the principal treatment option for control or cure of primary pelvic chondrosarcomas, as current adjuvant therapies remain ineffective. Iliosacral chondrosarcomas with involvement of the sciatic notch are sufficiently challenging tumors. However, when there is concomitant lumbar extension requiring resection of the pedicles to maintain negative surgical margins, transpedicular screw fixation is not possible, making reconstruction of the lumbopelvic junction extremely challenging. A patient with an iliosacral chondrosarcoma with lumbar spine extension is presented in this report to illustrate a novel lumbopelvic spinal construct. Following combined external pelvectomy and hemisacrectomy with contralateral L3-5 hemilaminectomy and ipsilateral pediculotomy, bicortical transvertebral body screws were substituted for the missing pedicles, resulting in the creation of "false pedicles," which were further supplemented with an autologous vascularized fibular strut graft from the amputated lower limb and applied to the lateral aspect of the vertebral bodies. The creation of false pedicles allowed for a robust reconstruction of the lumbopelvic junction, including maintaining pelvic ring integrity with a "neo-pelvis", creating a functional load-bearing construct adequate for early mobilization and ambulation. The biomechanical dynamics of this unique construct are also discussed.

Physiological complexity of acute traumatic brain injury in patients treated with a brain oxygen protocol: utility of symbolic regression in predictive modeling of a dynamical system.

Predictive modeling of emergent behavior, inherent to complex physiological systems, requires the analysis of large complex clinical data streams currently being generated in the intensive care unit. Brain tissue oxygen protocols have yielded outcome benefits in traumatic brain injury (TBI), but the critical physiological thresholds for low brain oxygen have not been established for a dynamical patho-physiological system. High frequency, multi-modal clinical data sets from 29 patients with severe TBI who underwent multi-modality neuro-clinical care monitoring and treatment with a brain oxygen protocol were analyzed. The inter-relationship between acute physiological parameters was determined using symbolic regression (SR) as the computational framework. The mean patient age was 44.4±15 with a mean admission GCS of 6.6±3.9. Sixty-three percent sustained motor vehicle accidents and the most common pathology was intra-cerebral hemorrhage (50%). Hospital discharge mortality was 21%, poor outcome occurred in 24% of patients, and good outcome occurred in 56% of patients. Criticality for low brain oxygen was intracranial pressure (ICP) ≥22.8 mm Hg, for mortality at ICP≥37.1 mm Hg. The upper therapeutic threshold for cerebral perfusion pressure (CPP) was 75 mm Hg. Eubaric hyperoxia significantly impacted partial pressure of oxygen in brain tissue (PbtO2) at all ICP levels. Optimal brain temperature (Tbr) was 34-35°C, with an adverse effect when Tbr≥38°C. Survivors clustered at [Formula: see text] Hg vs. non-survivors [Formula: see text] 18 mm Hg. There were two mortality clusters for ICP: High ICP/low PbtO2 and low ICP/low PbtO2. Survivors maintained PbtO2 at all ranges of mean arterial pressure in contrast to non-survivors. The final SR equation for cerebral oxygenation is: [Formula: see text]. The SR-model of acute TBI advances new physiological thresholds or boundary conditions for acute TBI management: PbtO2≥25 mmHg; ICP≤22 mmHg; CPP≈60-75 mmHg; and Tbr≈34-37°C. SR is congruous with the emerging field of complexity science in the modeling of dynamical physiological systems, especially during pathophysiological states. The SR model of TBI is generalizable to known physical laws. This increase in entropy reduces uncertainty and improves predictive capacity. SR is an appropriate computational framework to enable future smart monitoring devices.

Calcifying fibrous tumor of the spine.

OBJECTIVE: Calcifying fibrous tumor is a rare, benign soft-tissue tumor of unknown etiology, characterized by hyalinized collagenous fibrous tissue with psammomatous or dystrophic calcification and focal lymphoplasmacytic infiltrate known to involve different organ systems. Involvement of the spine and the presence of metaplastic ossification previously have not been reported. INTERVENTION: We report a 44-year-old female with progressive nontraumatic flank pain. Imaging revealed a left-sided retroperitoneal calcified mass attached to L5 body with no evidence of extension into the neural foramina, nearby vascular structures, or psoas muscle. The patient had an en bloc resection of the tumor via the transabdominal approach. A pathologic diagnosis of calcifying fibrosis with metaplastic ossification of the spine was reported. Postoperative recovery was uneventful and there is no recurrence after 18 months of follow-up. CONCLUSION: Calcifying fibrous tumor, a rare benign soft tissue tumor must be considered in the differential diagnosis of a retroperitoneal calcified mass closely associated with the spinal column. Spine surgeons should be aware of this rare pathologic disease entity and although its natural history is not clear, marginal excision is usually adequate.

Taming an old enemy: a profile of intracranial suppuration.

Intracranial suppurative disorders (ICSDs; brain abscess, empyema, and purulent ventriculitis), have been a scourge through the ages and attempts at curative surgery, as for cranial trauma, are considered to be one of the first true neurosurgical interventions performed. ICSDs, seen initially as a consequence of poor socioeconomic conditions and neglected otorhinogenic infections, predominantly manifest today as postsurgical complications, and/or in immunocompromised patients where they continue to result in significant neurologic morbidity and death. The reduction in the incidence of "old world" classic ICSDs can be attributed to the modernization of society, driven inter alia by a shift from an agricultural to an industrial economic society. It can also be coupled with pivotal achievements in public health and the dramatic developments in medicine in the 20th century. This trend was first noted in developed countries but now, with improved socioeconomic circumstances and globalization of medical technology, it is occurring in the developing regions of the world as well. Although ICSDs have undergone a metamorphosis in their clinical profile and despite their rarity in contemporary "developed world" neurosurgical practice, they still have undoubted potential for fatal consequences and continue to pose a significant challenge to the 21st-century neurosurgeon.

History of the vertebral venous plexus and the significant contributions of Breschet and Batson.

Before the 18th century, the vertebral venous plexus (VVP) received scant mention, had no clinical relevance, and was largely ignored by anatomists, most likely because of its location and nondistensible nature. Gilbert Breschet in 1819 provided the first detailed anatomic description of the VVP, describing it as a large plexiform valveless network of vertebral veins consisting of 3 interconnecting divisions and spanning the entire spinal column with connections to the cranial dural sinuses distributed in a longitudinal pattern, running parallel to and communicating with the venae cavae, and having multiple interconnections. More than a century passed before any work of significance on the VVP was noted. In 1940, Oscar V. Batson reported the true functionality of the VVP by proving the continuity of the prostatic venous plexus with the VVP and proposed this route as the most plausible explanation for the distribution of prostate metastatic disease. With his seminal work, Batson reclassified the human venous system to consist of the caval, pulmonary, portal, and vertebral divisions. Further advances in imaging technology confirmed Batson's results. Today, the VVP is considered part of the cerebrospinal venous system, which is regarded as a unique, large-capacitance, valveless plexiform venous network in which flow is bidirectional that plays an important role in the regulation of intracranial pressure with changes in posture and in venous outflow from the brain, whereas in disease states, it provides a potential route for the spread of tumor, infection, or emboli.

Brain abscess: management and outcome analysis of a computed tomography era experience with 973 patients.

OBJECTIVE: Brain abscess (BA) is a neurosurgical emergency and despite significant medical advances, it remains a surgical challenge. A single institution's two decade computed tomography era management experience with BA is reported. METHODS: A retrospective analysis of patients with BA, admitted to the Department of Neurosurgery, Wentworth Hospital, Durban, KwaZulu-Natal, South Africa, was performed. The medical records were analyzed for demographic, clinical, neuroimaging, neurosurgical and otolaryngology management, microbiological characteristics, and their relationship to outcome. RESULTS: During a 20-year period (1983-2002), 973 patients were treated. The mean age was 24.36 ± 15.1 years (range: 0.17-72 years) and 74.2% (n = 722) were men. The mean admission Glasgow Coma Score was 12.5 ± 2.83. The majority of BAs were supratentorial (n = 872, 89.6%). The causes were otorhinogenic (38.6%), traumatic (32.8%), pulmonary (7%), cryptogenic (4.6%), postsurgical (3.2%), meningitis (2.8%), cardiac (2.7%), and "other" (8.6%). Surgical drainage was performed in 97.1%, whereas 19 patients had nonoperative management. The incidence of BA decreased during the study period. Patient outcomes were good in 81.3% (n = 791), poor in 5.3% (n = 52), and death (13.4%, n = 130) at discharge. The management morbidity, which included postoperative seizures, was 24.9%. Predictors of mortality were cerebral infarction (odds ratio [OR] 31.1), ventriculitis (OR 12.9), coma (OR 6.8), hydrocephalus (OR 5.1), dilated pupils (OR 4.8), bilateral abscesses (OR 3.8), multiple abscesses (OR 3.4), HIV co-infection (OR 3.2), papilledema (OR 2.6), neurological deterioration (OR 2.4), and fever (OR 1.7). CONCLUSIONS: Optimal management of BA involves surgical drainage for medium-to-large abscesses (≥2.5 cm) with simultaneous eradication of the primary source, treatment of associated hydrocephalus, and administration of high doses of intravenous antibiotics. The incidence of BA is directly related to poor socioeconomic conditions and therefore, still poses a public health challenge in developing countries.

Nail-gun injury of the cervical spine: simple technique for removal of a barbed nail.

Although nail-gun injuries are a common form of penetrating low-velocity injury, impalement with barbed nails has been underreported to date. Barbed nails are designed to resist dislodgment once embedded, and any attempt at removal may splay open the barbs along the path of entry, with the potential for significant soft-tissue and neurovascular injury. A 25-year-old man sustained a nail impalement of the cervical spine from accidental discharge of a nail gun. The patient was noted to be fully conscious with no neurological deficits. Cervical Zone 2 impalement was noted, with only the head of the nail visible. Angiography revealed the nail lying just anterior to the right vertebral artery (VA), with compression of the vessel. Preoperatively, analysis of a similar nail revealed that orientation of the head determined position of the barbs. A deep neck dissection was then performed to the lateral aspect of the C-3 body, using the nail as a guide. Prior to removal, the nail was turned 180° to change the position of the barbs, to prevent injury to the VA. Nail removal was uneventful. The authors present a simple technique for treatment of a nail-gun injury with a barbed nail. Prior to removal, radiographic analysis of the impaled nail must be performed to determine the presence of barbs. If possible, the surgeon should request a similar nail for analysis prior to surgery. Last, the treating surgeon must have knowledge of the barbs' position at all times during nail removal, to prevent damage to critical structures.

Reconstruction of the pelvis and lumbar-pelvic junction using 2 vascularized autologous bone grafts after en bloc resection for an iliosacral chondrosarcoma.

Primary pelvic sarcomas remain challenging and complex surgical problems with significant potential for postoperative impairment of ambulation, as well as bowel, bladder, and sexual function. En bloc resection with negative tumor margins represents the best chance of control or cure as current adjuvant therapies remain ineffective. Tumor involvement of the sacrum with extension to the greater sciatic notch and ipsilateral ilium requires an external hemipelvectomy and sagittal sacrectomy with sacrifice of the lower extremity to achieve en bloc resection, followed by lumbar-pelvic reconstruction. A patient with an iliosacral chondrosarcoma is presented to illustrate a novel lumbar-pelvic reconstruction technique, in which vascularized soft tissue and 2 vascularized bone grafts were harvested from the amputated lower extremity and transferred to the pelvis as composite flaps to restore pelvic ring integrity, augment lumbar-pelvic fusion, and close the soft-tissue defect. The biomechanical dynamics of this unique construct are discussed.

Brain tissue oxygen monitoring in traumatic brain injury and major trauma: outcome analysis of a brain tissue oxygen-directed therapy.

OBJECT: Cerebral ischemia is the leading cause of preventable death in cases of major trauma with severe traumatic brain injury (TBI). Intracranial pressure (ICP) control and cerebral perfusion pressure (CPP) manipulation have significantly reduced the mortality but not the morbidity rate in these patients. In this study, the authors describe their 5-year experience with brain tissue oxygen (PbtO(2)) monitoring, and the effect of a brain tissue oxygen-directed critical care guide (PbtO(2)-CCG) on the 6-month clinical outcome (based on the 6-month Glasgow Outcome Scale score) in patients with TBIs. METHODS: One hundred thirty-nine patients admitted to Creighton University Medical Center with major traumatic injuries (Injury Severity Scale [ISS] scores >or= 16) and TBI underwent prospective evaluation. All patients were treated with a PbtO(2)-CCG to maintain a brain oxygen level > 20 mm Hg, and control ICP < 20 mm Hg. The role of demographic, clinical, and imaging parameters in the identification of patients at risk for cerebral hypooxygenation and the influence of hypooxygenation on clinical outcome were recorded. Outcomes were compared with those in a historical ICP/CPP patient cohort. Subgroup analysis of severe TBI was performed and compared to data reported in the Traumatic Coma Data Bank. RESULTS: The majority of injuries were sustained in motor vehicle crashes (63%), and diffuse brain injury was the most common abnormality (58%). Mechanism of injury, severity of TBI, pathological entity, neuroimaging results, and trauma indices were not predictive of ischemia. Factors affecting death included gunshot injury, poor trauma indices, subarachnoid hemorrhage, and coma. After standard resuscitation, 65% of patients had an initially low PbtO(2). Data are presented as means +/- SDs. Treatment with the PbtO(2)-CCG resulted in a 44% improvement in mean PbtO(2) (16.21 +/- 12.30 vs 23.65 +/- 14.40 mm Hg; p < 0.001), control of ICP (mean 12.76 +/- 6.42 mm Hg), and the maintenance of CPP (mean 76.13 +/- 15.37 mm Hg). Persistently low cerebral oxygenation was seen in 37% of patients at 2 hours, 31% at 24 hours, and 18% at 48 hours of treatment. Thus elevated ICP and a persistent low PbtO(2) after 2 hours represented increasing odds of death (OR 14.3 at 48 hours). Survivors and patients with good outcomes generally had significantly higher mean daily PbtO(2) and CPP values compared to nonsurvivors. Polytrauma, associated with higher ISS scores, presented an increased risk of vegetative outcome (OR 9.0). Compared to the ICP/CPP cohort, the mean Glasgow Outcome Scale score at 6 months in patients treated with PbtO(2)-CCG was higher (3.55 +/- 1.75 vs 2.71 +/- 1.65, p < 0.01; OR for good outcome 2.09, 95% CI 1.031-4.24) as was the reduction in mortality rate (25.9 vs 41.50%; relative risk reduction 37%), despite higher ISS scores in the PbtO(2) group (31.6 +/- 13.4 vs 27.1 +/- 8.9; p < 0.05). Subgroup analysis of severe closed TBI revealed a significant relative risk reduction in mortality rate of 37-51% compared with the Traumatic Coma Data Bank data, and an increased OR for good outcome especially in patients with diffuse brain injury without mass lesions (OR 4.9, 95% CI 2.9-8.4). CONCLUSIONS: The prevention and aggressive treatment of cerebral hypooxygenation and control of ICP with a PbtO(2)-directed protocol reduced the mortality rate after TBI in major trauma, but more importantly, resulted in improved 6-month clinical outcomes over the standard ICP/CPP-directed therapy at the authors' institution.

Collagen matrix duraplasty for posterior fossa surgery: evaluation of surgical technique in 52 adult patients. Clinical article.

OBJECT: Complete dural closure is not always possible following posterior fossa surgery, often requiring a graft to secure complete closure. The authors report their experience of using a collagen matrix as an onlay dural graft for repair of a posterior fossa dural defect. METHODS: A retrospective analysis was performed in 52 adult patients who had undergone collagen matrix duraplasty for the posterior fossa. Complications directly related to the dural graft, the presence or absence of hydrocephalus, and the role of closed suction wound drainage in relation to postsurgical pseudomeningoceles were analyzed. RESULTS: The indication for posterior fossa surgery was tumors in 32 patients, vascular abnormalities in 9 patients, and spontaneous cerebellar hemorrhage in 11 patients. Closed suction wound drainage was used in 23 patients (44.2%). Forty-eight (92.3%) of 52 patients had a dural defect > 2 cm. Nine (81.8%) of 11 patients with hydrocephalus required ventriculoperitoneal shunts. Complications of the surgery included pseudomeningoceles in 2 patients (3.8%; no closed suction wound drainage); superficial wound infections in 1 patient (1.9%; with closed suction wound drainage); and unexplained eosinophilia in 1 patient. CONCLUSIONS: Duraplasty using a collagen matrix is safe and effective in the posterior fossa, and is easy to use and time efficient. Meticulous layered wound closure, the detection and effective control of hydrocephalus, and the use of closed suction wound drainage reduces complications related to collagen matrix duraplasty for the posterior fossa.

The first direct human blood transfusion: the forgotten legacy of George W. Crile.

GEORGE W. CRILE is best known as the father of physiological surgery in the United States, a pioneer surgeon, an innovator and inventor, a founding member of the American College of Surgeons, and the principal founder of the Cleveland Clinic Foundation. However, Crile's legacy of performing the first direct blood transfusion in humans has been all but forgotten, even though the results were published in the leading scientific journals of the day. Crile's lifelong interest in the treatment of surgical shock led to his interest in blood transfusion. A chance visit to the laboratory of Alexis Carrel in 1902 resulted in Crile perfecting his technique for direct blood transfusion. He subsequently modified Carrel's anastomosis technique to administer a faster transfusion, investigated the use of blood transfusions in various clinical settings, and went on to introduce the concept and technique of blood transfusion to soldiers during World War I. In this report, we trace his long-time interest in blood transfusion and document the events that led to the first successful blood transfusion performed between 2 brothers on August 6, 1906, at St. Alexis Hospital, Cleveland, OH.

Management of hypertensive emergencies in acute brain disease: evaluation of the treatment effects of intravenous nicardipine on cerebral oxygenation.

OBJECT: Inappropriate sudden blood pressure (BP) reductions may adversely affect cerebral perfusion. This study explores the effect of nicardipine on regional brain tissue O(2) (PbtO(2)) during treatment of acute hypertensive emergencies. METHODS: A prospective case-control study was performed in 30 patients with neurological conditions and clinically elevated BP. All patients had a parenchymal PbtO(2) and intracranial pressure bolt inserted following resuscitation. Using a critical care guide, PbtO(2) was optimized. Intravenous nicardipine (5-15 mg/hour) was titrated to systolic BP < 160 mm Hg, diastolic BP < 90 mm Hg, mean arterial BP (MABP) 90-110 mm Hg, and PbtO(2) > 20 mm Hg. Physiological parameters-intracranial pressure, PbtO(2), central venous pressure, systolic BP, diastolic BP, MABP, fraction of inspired O(2), and cerebral perfusion pressure (CPP)-were compared before infusion, at 4 hours, and at 8 hours using a t-test. RESULTS: Sixty episodes of hypertension were reported in 30 patients (traumatic brain injury in 13 patients; aneurysmal subarachnoid hemorrhage in 11; intracerebral and intraventricular hemorrhage in 3 and 1, respectively; arteriovenous malformation in 1; and hypoxic brain injury in 1). Nicardipine was effective in 87% of the patients (with intravenous beta blockers in 4 patients), with a 19.7% reduction in mean 4-hour MABP (115.3 +/- 13.1 mm Hg preinfusion vs 92.9 +/- 11.40 mm Hg after 4 hours of therapy, p < 0.001). No deleterious effect on mean PbtO(2) was recorded (26.74 +/- 15.42 mm Hg preinfusion vs 27.68 +/- 12.51 mm Hg after 4 hours of therapy, p = 0.883) despite significant reduction in CPP. Less dependence on normobaric hyperoxia was achieved at 8 hours (0.72 +/- 0.289 mm Hg preinfusion vs 0.626 +/- 0.286 mm Hg after 8 hours of therapy, p < 0.01). Subgroup analysis revealed that 12 patients had low pretreatment PbtO(2) (10.30 +/- 6.49 mm Hg), with higher CPP (p < 0.001) requiring hyperoxia (p = 0.02). In this group, intravenous nicardipine resulted in an 83% improvement in 4- and 8-hour PbtO(2) levels (18.1 +/- 11.33 and 19.59 +/- 23.68 mm Hg, respectively; p < 0.01) despite significant reductions in both mean MABP (120.6 +/- 16.65 vs 95.8 +/- 8.3 mm Hg, p < 0.001) and CPP (105.00 +/- 20.7 vs 81.2 +/- 15.4 mm Hg, p < 0.001). CONCLUSIONS: Intravenous nicardipine is effective for the treatment of hypertensive neurological emergencies and has no adverse effect on PbtO(2).