Cost-effectiveness of the PECARN rules in children with minor head trauma.

STUDY OBJECTIVE: To improve the efficiency and appropriateness of computed tomography (CT) use in children with minor head trauma, clinical prediction rules were derived and validated by the Pediatric Emergency Care Applied Research Network (PECARN). The objective of this study was to conduct a cost-effectiveness analysis comparing the PECARN traumatic brain injury prediction rules to usual care for selective CT use. METHODS: We used decision analytic modeling to project the outcomes, costs, and cost-effectiveness of applying the PECARN rules compared with usual care in a hypothetical cohort of 1,000 children with minor blunt head trauma. Clinical management was directed by level of risk as specified by the presence or absence of variables in the PECARN traumatic brain injury prediction rules. Immediate costs of care (diagnostic testing, treatment [not including clinician time], and hospital stay) were derived on single-center data. Quality-adjusted life-year losses related to the sequelae of clinically important traumatic brain injuries and to radiation-induced cancers, number of CT scans, number of radiation-induced cancers, number of missed clinically important traumatic brain injury, and total costs were evaluated. RESULTS: Compared with the usual care strategy, the PECARN strategy was projected to miss slightly more children with clinically important traumatic brain injuries (0.26 versus 0.02 per 1,000 children) but used fewer cranial CT scans (274 versus 353), resulted in fewer radiation-induced cancers (0.34 versus 0.45), cost less ($904,940 versus $954,420), and had lower net quality-adjusted life-year loss (-4.64 versus -5.79). Because the PECARN strategy was more effective (less quality-adjusted life-year loss) and less costly, it dominated the usual care strategy. Results were robust under sensitivity analyses. CONCLUSION: Application of the PECARN traumatic brain injury prediction rules for children with minor head trauma would lead to beneficial outcomes and more cost-effective care.

Advances in surgical techniques for resection of childhood cerebellopontine angle ependymomas are key to survival.

BACKGROUND: Childhood cerebellopontine angle (CPA) ependymoma is an uncommon anatomical variant of posterior fossa ependymoma. In infants and young children, the tumor often goes undetected until it causes hydrocephalus. As CPA ependymomas grow, they distort the anatomy and encase cranial nerves and vessels, thereby making resection a formidable surgical challenge. PURPOSE: The purpose of this paper is to describe the surgical technique used to achieve gross total resection (GTR) of CPA ependymomas and demonstrate improved survival in these patients. MATERIALS AND METHODS: Surgical techniques used for GTR in 45 patients with CPA ependymoma treated from 1997 to 2008 are described. Results of those procedures are compared with data from 11 patients who previously underwent surgical resection (1985-1995). RESULTS: We achieved GTR in 43 (95.6%) patients and near-total resection in two (4.4%); the probability of progression-free survival was 53.8%, and that of overall survival was 64%. CONCLUSION: Our novel surgical techniques greatly improve central nervous system function and survival among pediatric patients with CPA ependymoma.

Effect of prophylactic transluminal balloon angioplasty on cerebral vasospasm and outcome in patients with Fisher grade III subarachnoid hemorrhage: results of a phase II multicenter, randomized, clinical trial.

BACKGROUND AND PURPOSE: Cerebral vasospasm continues to be a major cause of poor outcome in patients with ruptured aneurysms. Prophylactic Transluminal Balloon Angioplasty (pTBA) appeared to prevent delayed ischemic neurological deficit in a pilot study. A phase II multicenter randomized clinical trial was subsequently designed. METHODS: One hundred and seventy patients with Fisher Grade III subarachnoid hemorrhage were enrolled in the study. Of these, 85 patients were randomized to the treatment group and underwent pTBA within 96 hours after subarachnoid hemorrhage. Main end points of the study included the 3-month dichotomized Glasgow Outcome Score (GOS), development of delayed ischemic neurological deficit (DIND), occurrence of Transcranial Doppler (TCD) vasospasm, and length of stay in the ICU and hospital. RESULTS: The incidence of DIND was lower in the pTBA group (P=0.30) and fewer patients required therapeutic angioplasty to treat DIND (P=0.03). Overall pTBA resulted in an absolute risk reduction of 5.9% and a relative risk reduction of 10.4% unfavorable outcome (P=0.54). Good grade patients had absolute and relative risk reductions of respectively 9.5 and 29.4% (P=0.73). Length of stay in ICU and hospital was similar in both groups. Four patients had a procedure-related vessel perforation, of which three patients died. CONCLUSIONS: While the trial is unsuccessful as defined by the primary end point (GOS), proof of concept is confirmed by these results. Fewer patients tend to develop vasospasm after treatment with pTBA and there is a statistically significantly decreased need for therapeutic angioplasty. pTBA does not improve the poor outcome of patients with Fisher grade III subarachnoid hemorrhage.

Progressive cranial nerve palsy following shunt placement in an isolated fourth ventricle: case report.

Cranial nerve palsy is rarely seen after shunt placement in an isolated fourth ventricle. In the few reports of this complication, neuropathies are thought to be caused by catheter injury to the brainstem nuclei either during the initial cannulations or after shrinkage of the fourth ventricle. The authors treated a child who suffered from delayed, progressive palsies of the sixth, seventh, 10th, and 12th cranial nerves several weeks after undergoing ventriculoperitoneal shunt placement in the fourth ventricle. Magnetic resonance imaging revealed the catheter tip to be placed well away from the ventricular floor but the brainstem had severely shifted backward, suggesting that the pathogenesis of the neuropathies was traction on the affected cranial nerves. The authors postulated that the siphoning effect of the shunt caused rapid collapse of the fourth ventricle and while the cerebellar hemispheres were tented back by adhesions to the dura, the brainstem became the only mobile component in response to the suction forces. Neurological recovery occurred after surgical opening of the closed fourth ventricle and lysis of the basal cistern adhesions, which restored moderate ventricular volume and released the brainstem to its normal position.

The combined use of hydroxyapatite and bioresorbable plates to repair cranial defects in children.

OBJECT: Hydroxyapatite cement (HAC) is used with increasing frequency by craniofacial surgeons for building facial and skull base structures and by neurosurgeons for cranioplasty. Failures of HAC in cranioplasty have been attributed to breakage due to subjacent cerebrospinal fluid (CSF) pulsations through the dura mater. The authors describe a technique that involves inserting a resorbable MacroPore perforated plate to dampen CSF pulsations and then pouring HAC over the plate to fill a cranial defect and complete skull contouring. METHODS: Fifteen children ranging in age from 2 to 9.5 years were included in the study; the size of the skull defects in these patients ranged from 6.25 to 42.5 cm2, with a mean of 20.65 cm2. Patients in whom the combined MacroPore--HAC devices were implanted underwent follow-up examinations that included serial skull radiography and computerized tomography scans. No fractures of the implants were demonstrated. At 6 months postsurgery, small fingerlings of new bone growth appeared in the underside of the HAC plate, probably spanning from the dura through perforations in the MacroPore plate. At intervals ranging from 18 months to 20 years after implantation, the gaps between cranial bone edges and that the HAC began to blur, culminating in the complete bonding of host bone with the margin of the HAC plate. All implants remained radiopaque and maintained size, thickness, and shape. CONCLUSIONS: The findings of this study are promising and indicate that the combined use of HAC and a bioresorbable undercarriage that is osteoconductive, such as the MacroPore perforated plate, may produce a versatile and lasting cranioplasty in children.

Intraoperative computed tomography for intracranial electrode implantation surgery in medically refractory epilepsy.

OBJECT: Accurate placement of intracranial depth and subdural electrodes is important in evaluating patients with medically refractory epilepsy for possible resection. Confirming electrode locations on postoperative CT scans does not allow for immediate replacement of malpositioned electrodes, and thus revision surgery is required in select cases. Intraoperative CT (iCT) using the Medtronic O-arm device has been performed to detect electrode locations in deep brain stimulation surgery, but its application in epilepsy surgery has not been explored. In the present study, the authors describe their institutional experience in using the O-arm to facilitate accurate placement of intracranial electrodes for epilepsy monitoring. METHODS: In this retrospective study, the authors evaluated consecutive patients who had undergone subdural and/or depth electrode implantation for epilepsy monitoring between November 2010 and September 2012. The O-arm device is used to obtain iCT images, which are then merged with the preoperative planning MRI studies and reviewed by the surgical team to confirm final positioning. Minor modifications in patient positioning and operative field preparation are necessary to safely incorporate the O-arm device into routine intracranial electrode implantation surgery. The device does not obstruct surgeon access for bur hole or craniotomy surgery. Depth and subdural electrode locations are easily identified on iCT, which merge with MRI studies without difficulty, allowing the epilepsy surgical team to intraoperatively confirm lead locations. RESULTS: Depth and subdural electrodes were implanted in 10 consecutive patients by using routine surgical techniques together with preoperative stereotactic planning and intraoperative neuronavigation. No wound infections or other surgical complications occurred. In one patient, the hippocampal depth electrode was believed to be in a suboptimal position and was repositioned before final wound closure. Additionally, 4 strip electrodes were replaced due to suboptimal positioning. Postoperative CT scans did not differ from iCT studies in the first 3 patients in the series and thus were not obtained in the final 7 patients. Overall, operative time was extended by approximately 10-15 minutes for O-arm positioning, less than 1 minute for image acquisition, and approximately 10 minutes for image transfer, fusion, and intraoperative analysis (total time 21-26 minutes). CONCLUSIONS: The O-arm device can be easily incorporated into routine intracranial electrode implantation surgery in standard-sized operating rooms. The technique provides accurate 3D visualization of depth and subdural electrode contacts, and the intraoperative images can be easily merged with preoperative MRI studies to confirm lead positions before final wound closure. Intraoperative CT obviates the need for routine postoperative CT and has the potential to improve the accuracy of intracranial electroencephalography recordings and may reduce the necessity for revision surgery.

Computed tomography characteristics in pediatric versus adult traumatic brain injury.

OBJECT: Traumatic brain injury (TBI) is a leading cause of injury, hospitalization, and death among pediatric patients. Admission CT scans play an important role in classifying TBI and directing clinical care, but little is known about the differences in CT findings between pediatric and adult patients. The aim of this study was to determine if radiographic differences exist between adult and pediatric TBI. METHODS: The authors retrospectively analyzed TBI registry data from 1206 consecutive patients with nonpenetrating TBI treated at a Level 1 adult and pediatric trauma center over a 30-month period. RESULTS: The distribution of sex, race, and Glasgow Coma Scale (GCS) score was not significantly different between the adult and pediatric populations; however, the distribution of CT findings was significantly different. Pediatric patients with TBI were more likely to have skull fractures (OR 3.21, p < 0.01) and epidural hematomas (OR 1.96, p < 0.01). Pediatric TBI was less likely to be associated with contusion, subdural hematoma, subarachnoid hemorrhage, or compression of the basal cisterns (p < 0.05). Rotterdam CT scores were significantly lower in the pediatric population (2.3 vs 2.6, p < 0.001). CONCLUSIONS: There are significant differences in the CT findings in pediatric versus adult TBI, despite statistical similarities with regard to clinical severity of injury as measured by the GCS. These differences may be due to anatomical characteristics, the biomechanics of injury, and/or differences in injury mechanisms between pediatric and adult patients. The unique characteristics of pediatric TBI warrant consideration when formulating a clinical trial design or predicting functional outcome using prognostic models developed from adult TBI data.

Decompressive craniectomy using gelatin film and future bone flap replacement.

OBJECT: Decompressive craniectomy plays an important role in the management of patients with traumatic brain injury (TBI) and stroke. Risks of decompressive craniectomy include those associated with cranioplasty, and may be related to adhesions that develop between the brain surface and overlying scalp and temporalis muscle. The authors report their institutional experience using a multilayered technique (collagen and gelatin film barriers) to facilitate safe and rapid cranioplasty following decompressive craniectomy. METHODS: The authors conducted a retrospective chart review of 62 consecutive adult and pediatric patients who underwent decompressive craniectomy and subsequent cranioplasty between December 2007 and January 2011. Diagnoses included TBI, ischemic stroke, intraparenchymal hemorrhage, or subarachnoid hemorrhage. A detailed review of clinical charts was performed, including anesthesia records and radiographic study results. RESULTS: The majority of patients underwent unilateral hemicraniectomy (n = 56), with indications for surgery including midline shift (n = 37) or elevated intracranial pressure (n = 25). Multilayered decompressive craniectomy was safe and easy to perform, and was associated with a low complication rate, minimal operative time, and limited blood loss. CONCLUSIONS: Decompressive craniectomy repair using an absorbable gelatin film barrier facilitates subsequent cranioplasty by preventing adhesions between intracranial contents and the overlying galea aponeurotica and temporalis muscle fascia. This technique makes cranioplasty dissection faster and potentially safer, which may improve clinical outcomes. The indications for gelatin film should be expanded to include placement in the epidural space after craniectomy.

A genome-wide association study identifies susceptibility loci for nonsyndromic sagittal craniosynostosis near BMP2 and within BBS9.

Sagittal craniosynostosis is the most common form of craniosynostosis, affecting approximately one in 5,000 newborns. We conducted, to our knowledge, the first genome-wide association study for nonsyndromic sagittal craniosynostosis (sNSC) using 130 non-Hispanic case-parent trios of European ancestry (NHW). We found robust associations in a 120-kb region downstream of BMP2 flanked by rs1884302 (P = 1.13 × 10(-14), odds ratio (OR) = 4.58) and rs6140226 (P = 3.40 × 10(-11), OR = 0.24) and within a 167-kb region of BBS9 between rs10262453 (P = 1.61 × 10(-10), OR = 0.19) and rs17724206 (P = 1.50 × 10(-8), OR = 0.22). We replicated the associations to both loci (rs1884302, P = 4.39 × 10(-31) and rs10262453, P = 3.50 × 10(-14)) in an independent NHW population of 172 unrelated probands with sNSC and 548 controls. Both BMP2 and BBS9 are genes with roles in skeletal development that warrant functional studies to further understand the etiology of sNSC.

Anemia in the setting of traumatic brain injury: the arguments for and against liberal transfusion.

Anemia is recognized as a possible cause of secondary injury following traumatic brain injury (TBI). Cogent arguments can be made for both liberal and restrictive blood transfusion practices in this setting. In this narrative review, we summarize available knowledge regarding the risks of anemia and transfusion in patients with TBI. Laboratory studies using animal models and healthy human subjects suggest that anemia below a hemoglobin (Hb) concentration of 7 g/dL results in impaired brain function and below 10 g/dL may be detrimental to recovery from TBI. Clinical studies that have evaluated the association of anemia with clinical outcomes have not consistently demonstrated harm, but they generally have important methodological weaknesses. Alternatively, studies that have analyzed transfusion as a predictor of worse outcome have consistently identified such an association, but these studies may involve residual confounding. What little information exists from randomized trials that have included patients with TBI and evaluated liberal versus restrictive transfusion strategies is inconclusive. Since anemia in the setting of TBI is relatively common and there is considerable variation in transfusion preferences, greater study of this topic - preferably with one or more rigorous, adequately powered, non-inferiority randomized trials - is desirable.

Minicraniotomy versus bur holes for evacuation of chronic subdural collections in infants-a preliminary single-institution experience.

OBJECT: Various surgical interventions have been described to evacuate chronic subdural collections (CSCs) of infancy. These include transfontanel percutaneous aspiration, subdural drains, placement of bur hole(s) with or without a subdural drain, and shunting. Shunt placement typically provides good long-term success (resolution of the subdural fluid), but comes with well-known early and late complications. Recently, the authors have used a mini-osteoplastic craniotomy technique with the goal of definitively treating these children with a single surgery while avoiding the many issues associated with a shunt. They describe their procedure and compare it with the traditional bur hole technique. METHODS: In this single-institution retrospective study, the authors evaluated 26 cases involving patients who underwent treatment for CSC. Preoperative, intraoperative, and postoperative data were reviewed, including radiographic findings (density of the subdural fluid and ventricular and subarachnoid space size), neurological examination findings, and intraoperative fluid description. The primary outcome was treatment failure, defined as the patient requiring any subsequent surgical intervention after the index procedure (minicraniotomy or bur hole placement). RESULTS: Fifteen patients (10 male and 5 female; median age 5.1 months) collectively underwent 27 minicraniotomy procedures (each procedure representing a hemisphere that was treated). In the bur hole group, there were 11 patients (6 male and 5 female; median age 4.6 months) with 18 hemispheres treated. Both groups had subdural drains placed. The average follow-up for each treatment group was just over 7 months. Treatment failure occurred in 2 patients (13%) in the minicraniotomy group compared with 5 patients (45%) in the bur hole group (p = 0.09). Furthermore, the 2 patients who had treatment failure in the minicraniotomy group required 1 subsequent surgery each, whereas the 5 in the bur hole group needed a total of 9 subsequent surgeries. Eventually, 80% of the patients in the minicraniotomy group and 70% of those in the bur hole group had resolution of the subdural collections on the last imaging study. CONCLUSIONS: The minicraniotomy technique may be a superior technique for the treatment of CSCs in infants compared with bur hole evacuation. The minicraniotomy provides greater visualization of the subdural space and allows more aggressive evacuation of the fluid, better irrigation of the space, the ability to fenestrate any accessible membranes safely, and continued egress of fluid into the subgaleal space. Although this preliminary report has obvious limitations, evaluation of this technique may be worthy of a prospective, multiinstitutional collaborative effort.

Spinal dural closure with nonpenetrating titanium clips in pediatric neurosurgery.

OBJECT: The authors report a retrospective review of their experience using nonpenetrating titanium anastomotic clips for dural closure in 27 pediatric cases (26 patients) of spinal surgery for a variety of diagnoses. The goal of this review was to define the utility of these clips in pediatric neurosurgical spinal procedures, identify complications of their use, and assess the effects on postoperative imaging because of their use. METHODS: Institutional review board approval was obtained for a retrospective chart review of all patients in whom titanium dural clips had been utilized. Patients were identified over a 2-year period using hospital and clinic records, and data were collected on the patient demographics, surgical diagnosis and procedure, durotomy location and length, and adjunctive closure methods. Postoperative complications were assessed. When available, postoperative imaging data were reviewed. RESULTS: Twenty-six patients underwent 27 operations over a 20-month period. They ranged in age from 2.5 months to 18.5 years, with a median age of 3.2 years and an average age of 5.8 years. The operative diagnosis was some form of spinal dysraphism in 19 patients, with a syrinx or dural tear in 2 patients each, and an arachnoid cyst in 3 cases; 1 patient had a tumor resected. Operative levels included lumbosacral (19), thoracic (7), and cervical (1). Dural exposure was limited to 1 laminar level in 16 cases, 2 levels in 8, and 3 levels in 1; 2 cases involved focal dural tears. A combination of additional hemostatic and tissue sealant materials was applied over the clips in 16 cases. One patient required reoperation 13 months after clip placement. Prior clip use did not make subsequent exposure and opening more complicated. No significant complications were identified in the follow-up period ranging from 1 to 24 months. There were no documented CSF leaks. The clips are not easily seen on plain radiographs and did not cause artifacts or distortion on either CT or MR imaging. CONCLUSIONS: Nonpenetrating titanium anastomotic clips afford an effective means of closure while limiting the exposure needed, and thus allowing more minimally invasive approaches. In tight spaces, dural closure is accomplished more easily and faster with the clips as compared with conventional suturing. No significant complications were seen from clip use, and the clips did not interfere with postoperative imaging.

Endovascular management of cerebral vasospasm.

Cerebral vasospasm remains a leading cause of death and disability in patients with ruptured cerebral aneurysms. The development of endovascular intervention in the past two decades has shown promising results in the treatment of vasospasm. Endovascular techniques that have been used in humans include intra-arterial infusion of vasorelaxants and direct mechanical dilation with transluminal balloon angioplasty. This article reviews the current indications and role of endovascular therapy in the management of cerebral vasospasm, its clinical significance, and potential future therapies.

Comparison of minimally invasive and conventional open posterolateral lumbar fusion using magnetic resonance imaging and retraction pressure studies.

OBJECTIVE: To determine whether minimally invasive lumbar spinal fusion results in less paraspinal muscle damage than conventional open posterior fusion. METHODS: The maximum intramuscular pressure (IMP) generated by a minimally invasive and standard open retractor was compared in cadavers using an ultra-miniature pressure transducer. In a second clinical study, eight patients with either minimally invasive or open posterolateral lumbar spinal fusion underwent magnetic resonance imaging (MRI) scanning approximately 6 months post surgery. MRI was used to estimate edema and atrophy within multifidus, with T2 mapping and diffusion-weighted imaging allowing quantification of differences between the two surgical techniques. RESULTS: IMP measured with the minimally invasive retractor was 1.4 versus 4.7 kPa with the open retractor (P < 0.001). The minimally invasive retractor produced a transient maximal IMP only on initial expansion. Maximum IMP was constant throughout open retractor deployment. Striking visual differences in muscle edema were seen between open and minimally invasive groups on MRI. The mean T2 relaxation time at the level of fusion was 47 milliseconds in the minimally invasive and 90 milliseconds in the open group (P = 0.013). The mean apparent diffusion coefficient was 1357 x 10(-6) mm/s and 1626 x 10(-6) mm(2)/s (P = 0.0184), respectively. CONCLUSIONS: The peak IMP generated by the minimally invasive retractor was significantly less than with the open retractor. Postoperatively, less muscle edema was demonstrated after the minimally invasive lumbar spinal fusion, with lower mean T2 and apparent diffusion coefficient measurements supporting the hypothesis that less damage occurs using a minimally invasive approach.