✓ Extracranial meningiomas comprise approximately 2% of all meningiomas. Involvement of peripheral nerves by meningioma, either by a primary tumor or through secondary extension of an intraaxial lesion, is a much rarer entity; there have been only two reported primary brachial plexus meningiomas and one description of secondary involvement of the brachial plexus by extension of an intraaxial lesion. Although thoracic cavity meningiomas have been described in the literature, their pathogenesis is poorly understood. The authors present the case report of a 36-year-old man who was initially treated for a thoracic spinal meningioma that infiltrated the brachial plexus. After resection, progressive and massive growth with infiltration of the brachial plexus and pleural cavity occurred over a 5-year period despite radio- and chemotherapy. The case report is followed by a review of the literature of this rare entity.
Massive growth of a meningioma into the brachial plexus and thoracic cavity after intraspinal and supraclavicular resection
Case report and review of the literature
Edward R. Smith, Mark Ott, John Wain, David N. Louis and E. Antonio Chiocca
Edward R. Smith, William E. Butler and Fred G. Barker II
Object. Death after ventriculoperitoneal (VP) shunt surgery is uncommon, and therefore it has been difficult to study. The authors used a population-based national hospital discharge database to examine the relationship between annual hospital and surgeon volume of VP shunt surgery in pediatric patients and in-hospital mortality rates.
Methods. All children in the Nationwide Inpatient Sample (1998–2000, age 90 days—18 years) who underwent VP shunt placement or shunt revision as the principal procedure were included. Main outcome measures were in-hospital mortality rates, length of stay (LOS), and total hospital charges.
Overall, 5955 admissions were analyzed (253 hospitals, 411 surgeons). Mortality rates were lower at high-volume centers and for high-volume surgeons. In terms of hospital volume, the mortality rate was 0.8% at lowest-quartile-volume centers (< 28 admissions/year) and 0.3% at highest-quartile-volume centers (> 121 admissions/year). In terms of surgeon volume, the mortality rate was 0.8% for lowest-quartile-volume providers (< nine admissions/year) and 0.1% for highest-quartile-volume providers (> 65 admissions/year). After multivariate adjustment for demographic variables, emergency admission and presence of infection, hospital volume of care remained a significant predictor of death (odds ratio [OR] for a 10-fold increase in caseload 0.38; 95% confidence interval [CI] 0.18–0.81). Surgeon volume of care was statistically significant in a similar multivariate model (OR for a 10-fold increase in caseload 0.3; 95% CI 0.13–0.69). Length of stay was slightly shorter and total hospital charges were slightly higher at higher-volume centers, but the differences were not statistically significant.
Conclusions. Pediatric shunt procedures performed at high-volume hospitals or by high-volume surgeons were associated with lower in-hospital mortality rates, with no significant difference in LOS or hospital charges.
Ralph G. Dacey Jr.
Edward S. Ahn and Edward R. Smith
✓Infratentorial and spinal subdural hematomas (SDHs) from traumatic injury in the pediatric population occur with such rarity that they can present the clinician with a challenge in diagnosis and management. When such hematomas are correctly identified, clinicians must decide whether to evacuate the lesion or manage it expectantly. The authors discuss the case of a 4-year-old child who presented with a clival and spinal SDH after a fall from a fourth-story window. The clinical and radiographic findings support a possible mechanism of evolution of these lesions. There is little evidence to guide management of clival and spinal SDHs. This case supports the evaluation for a spinal SDH when a clival hematoma is diagnosed. In the setting of a good neurological examination, expectant management can be an appropriate method of treatment. Additionally, this case lends insight into the pathophysiology of spinal SDHs. Unlike its intracranial counterpart, the spinal subdural space lacks bridging veins. The mechanism of formation of spinal SDHs after trauma has been heretofore relatively unclear. The images in this case support the hypothesis that redistribution of the clival SDH to dependent areas in the spinal subdural space is a significant mechanism in the evolution of these lesions.
Edward R. Smith, William E. Butler and Fred G. Barker II
Concern for patient safety, among other reasons, recently prompted sweeping changes in resident work policies in the US. Some have speculated that the arrival of new interns and residents at teaching hospitals each July might cause an annual transient increase in poor patient outcomes and inefficient care.
Data were analyzed for 4323 craniotomies for tumor resection and 22,072 shunt operations performed in pediatric patients between 1988 and 2000 in US nonfederal hospitals (Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality, Rockville, MD). In-hospital mortality rates, discharge outcome, complications, and efficiency measures (length of stay [LOS] and hospital charges) for patients treated in July and August were compared with similar data for patients in other months.
There were no significant increases in any adverse end point for either tumor or shunt operations in July and August. Odds ratios (95% confidence interval [CI]) for outcome of tumor craniotomies performed in July and August compared with outcome for tumor craniotomies performed in other months were as follows: for mortality rate, 0.43 (0.14–1.32); for adverse discharge disposition, 1.03 (0.71–1.51); for neurological complications, 1.00 (0.63–1.59); for transfusion, 0.70 (0.41–1.19). Hospital charges were 0.5% lower (range −6 to 5%) in July and August, and LOS was 3% shorter (range −8 to 3%). Odds ratios (95% CI) for July or August shunt surgery compared with shunt surgery performed in other months were as follows: for mortality rate, 0.96 (0.58–1.60); for adverse discharge disposition, 0.85 (0.66–1.11); for neurological complications, 1.27 (0.75–2.16); for transfusion, 0.81 (0.48–1.37). Hospital charges were 0.2% higher in July and August (range −3 to 3%), and LOS was 3% shorter (range −5 to 0.5%).
Although moderate increases in some adverse end points could not be excluded, there was no evidence that brain tumor or shunt surgery performed in pediatric patients at US teaching hospitals during July and August is associated with more frequent adverse patient outcome or inefficient care than similar surgery performed during other months.
R. Michael Scott
Case report and review of the literature
Patrick J. Codd, Ron I. Riesenburger, Paul Klimo Jr., Jonathan R. Slotkin and Edward R. Smith
✓ Aneurysmal bone cysts (ABCs) are benign, highly vascular osseous lesions characterized by cystic, blood-filled spaces surrounded by thin perimeters of expanded bone. Children and young adults are most often affected by spinal ABCs; more than 75% of patients are younger than 20 years old at presentation. Although ABCs have been documented in all areas of the axial and appendicular skeleton, ABCs of the spine present unique challenges due to the risk of vertebral destabilization, pathological fracture and vertebral body (VB) collapse, and neurological compromise. The authors describe the case of an 8-year-old child who presented with low-back pain and was subsequently found to have a lumbar ABC causing vertebra plana of the L-3 VB. They also review the literature on ABCs of the spine. This case highlights the importance of considering an ABC in the differential diagnosis when vertebra plana is seen in pediatric patients.
Ian F. Dunn, Graeme F. Woodworth, Adnan H. Siddiqui, Edward R. Smith, G. Edward Vates, Arthur L. Day and Liliana C. Goumnerova
✓ Traumatic intracranial aneurysms are rare in adults but account for up to 33% of all aneurysms encountered in a pediatric population. The most common location of such lesions in children is the pericallosal or adjacent branch of the anterior cerebral artery, where a head impact exerts sudden decelerating shearing forces on the arteries tethered on the brain surface against an immobile falx cerebri, weakening the arterial wall. This action can lead to dissection of the damaged vascular layers, with resultant expansion of the affected site into a fusiform aneurysm. Pericallosal aneurysms following a penetrating intracranial injury have also been described, and the resultant lesion in some cases can be a pseudoaneurysm. The incidence of iatrogenic pericallosal artery aneurysms, however, is extremely rare.
The authors describe the first reported case of a traumatic pericallosal artery aneurysm following transcallosal surgery. This 6-year-old boy underwent resection of a hypothalamic pilocytic astrocytoma, which was approached via the transcallosal corridor. A follow-up magnetic resonance image obtained within 1 year of surgery disclosed a small flow void off the right pericallosal artery, which was initially interpreted as residual tumor. Serial investigations showed the lesion enlarging over time, and subsequent angiography revealed a round 7-mm pericallosal artery aneurysm with an irregularly shaped 2- to 3-mm lumen. The aneurysm was difficult to treat with clip reconstruction or suturing of the affected segment, and an excellent outcome was ultimately achieved with resection of the lesion and autogenous arterial graft interposition. The authors also discuss the likely pathophysiology of the aneurysm and the surgical procedures undertaken to treat it.
Brian V. Nahed, Aneela Darbar, Robert Doiron, Ali Saad, Caroline D. Robson and Edward R. Smith
✓Choroid plexus cysts are common and typically asymptomatic abnormal folds of the epithelial lining of the choroid plexus. Rarely, these cysts may gradually enlarge and cause outflow obstruction of cerebrospinal fluid. The authors present a case of a large choroid plexus cyst causing acute hydrocephalus in a previously healthy 2-year-old boy. The patient presented with markedly declining mental status, vomiting, and bradycardia over the course of several hours. Computed tomography scans demonstrated enlarged lateral and third ventricles with sulcal effacement, but no obvious mass lesions or hemorrhage. There was no antecedent illness or trauma. A right frontal external ventricular drain was placed in the patient, resulting in decompression of only the right lateral ventricle. Magnetic resonance (MR) imaging demonstrated a lobulated cyst arising from the choroid plexus of the left lateral ventricle and herniating through the foramen of Monro into the third ventricle, occluding both the foramen of Monro and the cerebral aqueduct. The patient underwent an endoscopic fenestration of the cyst, and histological results confirmed that it was a choroid plexus cyst. Postoperative MR imaging showed a marked reduction in the cyst size. The cyst was no longer in the third ventricle, the foramen of Monro and the aqueduct were patent, and the ventricles were decompressed. The patient was discharged home with no deficits. To the authors' knowledge, there are no previous reports of a choroid plexus cyst causing acute hydrocephalus due to herniation into the third ventricle. This case is illustrative because it describes this entity for the first time, and more importantly highlights the need to obtain a diagnosis when a patient presents with acute hydrocephalus without a clear cause.
Edward R. Smith and R. Michael Scott
Progression of vasculopathy associated with moyamoya syndrome is extremely variable. The authors review their experience in patients with unilateral moyamoya syndrome to identify factors predictive of contralateral clinical and imaging-documented disease progression.
The authors reviewed the clinical and imaging records of all patients with moyamoya syndrome and unilateral disease who underwent cerebral revascularization surgery between January 1985 and June 2006 by using a standardized surgical procedure, pial synangiosis.
Of 235 surgically treated patients with moyamoya syndrome, 33 (14%) presented with unilateral disease (4 adults and 29 children). There were 16 female and 17 male patients, with an average age of 10.4 years (26.8 years for adults and 8.1 years for children; range 1.5–39 years). Twenty patients presented with left-sided disease and 13 with right-sided disease.
The average follow-up after surgery was 5.3 years (3.1 years for adults and 5.6 years for children; range 1–16 years). During this period, 10 (30%) of 33 patients progressed to bilateral disease. The mean time until disease progression was 2.2 years (range 0.5–8.5 years). Factors associated with progression in this series included contralateral abnormalities on initial angiography, previous history of congenital cardiac anomaly, cranial irradiation, Asian ancestry, and familial moyamoya syndrome. Young age at diagnosis was associated with a more rapid rate of progression (age < 7 years, 0.9 years to progression and age ≥ 7 years, 3.1 years to progression).
Of patients with unilateral moyamoya syndrome, 30% will have progression of arteriopathy during long-term follow-up. In this series, the average time of progression from unilateral to bilateral angiographic disease was 2.2 years. Several factors, including contralateral abnormalities on initial imaging, congenital cardiac anomaly, previous cranial irradiation, Asian ancestry, and familial moyamoya syndrome, were associated with an increased risk of progression. Patients with known unilateral angiographic disease should undergo continued monitoring by using MR imaging and MR angiography at regular intervals. Treatment with pial synangiosis is safe and confers durable protection against stroke in patients with both bilateral and unilateral moyamoya syndrome.