Clinical and oncological outcomes in single-stage versus staged surgery for pediatric craniopharyngiomas: a multicenter retrospective study.

PURPOSE: Craniopharyngiomas (CPGs) are aggressive brain tumors responsible of severe morbidity in children. The best treatment strategies are under debate. Our study evaluates surgical, pituitary, and hypothalamic outcomes of a tailored staged-surgical approach compared to a single-stage radical approach in children with CPGs. METHODS: Multicenter retrospective study enrolling 96 children treated for CPGs in the period 2010-2022. The surgical management was selected after a multidisciplinary evaluation. Primary endpoint includes the inter-group comparison of preservation/improvement of hypothalamic-pituitary function, the extent of resection, and progression-free survival (PFS). Secondary endpoints include overall survival (OS), morbidity, and quality of life (QoL). RESULTS: Gross Total Resection (GTR) was reached in 46.1% of cases in the single-stage surgery group (82 patients, age at surgery 9 ± 4.7 years) and 33.3% after the last operation in the staged surgery group (14 patients age 7.64 ± 4.57 years at first surgery and 9.36 ± 4.7 years at the last surgery). The PFS was significantly higher in patients addressed to staged- compared to single-stage surgery (93.75% vs 70.7% at 5 years, respectively, p = 0.03). The recurrence rate was slightly higher in the single-stage surgery group. No significant differences emerged in the endocrinological, visual, hypothalamic outcome, OS, and QoL comparing the two groups. CONCLUSIONS: In pediatric CPGs' surgical radicality and timing of intervention should be tailored considering both anatomical extension and hypothalamic-pituitary function. In selected patients, a staged approach offers a safer and more effective disease control, preserving psychophysical development.

Human cerebral microcirculation and oxygen saturation during propofol-induced reduction of bispectral index.

BACKGROUND: Propofol reduces cerebral blood flow (CBF) secondary to cerebral metabolic depression. However, in vitro and in vivo studies demonstrate that propofol directly dilates the vascular smooth muscle. This study investigates the effects of propofol-induced changes in bispectral index (BIS) on cerebral microcirculation and oxygenation during craniotomies. METHODS: In 21 craniotomy patients undergoing routine craniotomy, anaesthesia was maintained with propofol 4-10 mg kg⁻¹ h⁻¹ and remifentanil 0.1-0.4 µg kg⁻¹ min⁻¹. Propofol concentration was adjusted to achieve higher BIS (target 40) or lower BIS (target 20). Regional measurements of capillary venous blood flow (rvCBF), oxygen saturation (srvO2), and haemoglobin amount (rvHb) at 2 mm (grey matter) and 8 mm (white matter) cerebral depth were randomly performed at higher and lower BIS by combined laser-Doppler flowmetry and spectroscopy. Calculations: approximated arteriovenous difference in oxygen content (avDO2) and cerebral metabolic rate of oxygen (aCMRO2). RESULTS: mean values (sd). STATISTICS: Mann-Whitney test (*P<0.05). Results Human cerebral microcirculation and oxygen saturation were assessed at propofol dosages 5.1 (2.3) mg kg⁻¹ h⁻¹ [BIS 40 (9)] and 7.8 (2.1) mg kg⁻¹ h⁻¹ [BIS 21 (7)]. Propofol-induced reduction in BIS resulted in increased srvO2 (P=0.018), and decreased avDO2 (P=0.025) and aCMRO(2) (P=0.022), in 2 mm cerebral depth, while rvCBF and rvHb remained unchanged. In 8 mm cerebral depth, srvO2, rvCBF, rvHb, and also calculated parameters avDO2 and aCMRO2 remained unaltered. CONCLUSIONS: Findings suggest alteration of the CBF/CMRO2 ratio by propofol in cortical brain regions; therefore, it might be possible that propofol affects coupling of flow and metabolism in the cerebral microcirculation.

High-definition imaging in spinal neuroendoscopy.

BACKGROUND: Spinal endoscopy is still under controversial discussion. An often acclaimed critic is the poor endoscopic image quality in comparison with the microscope. Since high-definition digital cameras have recently been introduced into spinal neuroendoscopy, the aim of the current study is to examine whether superior image quality has a relevant impact on intraoperativen orientation. MATERIAL AND METHODS: A lumbar endoscopic discectomy was recorded simultaneously in High-Definition resolution (HD) and Standard-Definition resolution (SD). 10 experienced spinal surgeons were asked to identify predefined as well as not predefined anatomic structures in HD and SD resolution. Additionally, the video quality was rated with grades from 1 ("very good") to 6 ("poor"). RESULTS: Out of 14 predefined structures an average of 7.8+/-3.3 structures (55.71%) were identified in HD, 4.4+/-3.2 structures (31.43%) in SD (p=0.03). Out of 14 not predefined anatomical structures, 5.9+/-3.6 were correctly identified in HD, 2.6+/-2.5 in SD (p=0.05). Misinterpretation of structures occurred in 1.4+/-1 cases in HD, compared to 3+/-2.2 in SD (p=0.05). Subjective impression of video quality was rated 2.2 ("good") for HD, 3.0 ("satisfactory") for SD (p=0.03). CONCLUSION: HD in endoscopic discectomy accounts for a significantly more reliable identification of anatomic structures in freeze-images in comparison with standard definition images. Additionally, the subjective impression of video quality is significantly better in HD. This superior identification of structures might contribute to improve intraoperative orientation in endoscopic neurosurgery using high definition quality technology.

Value of endoscopic third ventriculostomy instead of shunt revision.

BACKGROUND: The purpose of this study was to analyze the value of endoscopic third ventriculostomy (ETV) in patients with shunt malfunction or infection. METHODS: ETV was performed in 263 patients in Greifswald between 1993 and 2008. We reviewed the data of all patients with previous shunts who underwent ETV instead of shunt revision. The procedure was successful when subsequent shunt implantation was avoided. RESULTS: Neuroendoscopy was performed in 30/31 previously shunted patients. The average age of the patients was 26.4 years ranging from 6 months to 69 years (male/female ratio: 18/12). The primary cause of hydrocephalus was aqueductal stenosis in 11, myelomeningocele in 5, posthemorrhagic in 5, postmeningitic in 3, tumor-related obstruction in 2, supracerebellar arachnoid cyst in 2, posttraumatic in 1 and a complex congenital hydrocephalus in 1. ETV was successful in 18 patients (60%) with a mean follow-up period of 51 months. 12 patients (40%) did not benefit from ETV and required a permanent shunt. 11 of them received the shunt within 3 months after failed ETV. ETV failed in all children <2 years of age. A benefit of ETV without subsequent shunt procedures was recognized in 18/27 (66.7%) with an obstructive and 0/3 (0%) patients with a communicating cause of the hydrocephalus. Complications occurred in 2 patients (6.7%). CONCLUSIONS: ETV is a potential treatment option when shunts fail in patients with obstructive hydrocephalus. If MR imaging shows no obstruction, a shunt revision is recommended. Patients with a posthemorrhagic and postmeningitic hydrocephalus are poor candidates for ETV.

Observation of persistent species temperature separation in inertial confinement fusion mixtures.

The injection and mixing of contaminant mass into the fuel in inertial confinement fusion (ICF) implosions is a primary factor preventing ignition. ICF experiments have recently achieved an alpha-heating regime, in which fusion self-heating is the dominant source of yield, by reducing the susceptibility of implosions to instabilities that inject this mass. We report the results of unique separated reactants implosion experiments studying pre-mixed contaminant as well as detailed high-resolution three-dimensional simulations that are in good agreement with experiments. At conditions relevant to mixing regions in high-yield implosions, we observe persistent chunks of contaminant that do not achieve thermal equilibrium with the fuel throughout the burn phase. The assumption of thermal equilibrium is made in nearly all computational ICF modeling and methods used to infer levels of contaminant from experiments. We estimate that these methods may underestimate the amount of contaminant by a factor of two or more.

First experimental results with a new waterjet dissector: Erbejet 2.

BACKGROUND: Waterjet dissection represents a useful technique for many surgical procedures. In this experimental study, the technical features and dissection qualities of the new Erbejet 2 with its new pump and nozzle applicator system are evaluated for its neurosurgical use compared to the established Helix Hydro-Jet. METHODS: One hundred twenty-six fresh cadaveric pig brains were simultaneously cut with the Helix Hydro-Jet and Erbejet 2. Different pressure levels were applied to cerebral tissue with and without meninges, cerebellum and brainstem. Additionally, dissection characteristics of various cutting media were investigated. FINDINGS: There was a nearly equal dissection quality at up to 10 bar of both instruments. In contrast to the Helix Hydro-Jet, Erbejet 2 application at higher pressures resulted in an almost linear increase of dissection depth with a small standard deviation. Smoother cutting margins and less foaming were found. Preserved vessels were observed with both devices. Hydroxyaethyl starch led, in contrast to Ringer's solution and isotonic saline solution, to increased dissection width and more foaming. CONCLUSIONS: The new Erbejet 2 is more precise, with almost linear correlation of pressure and dissection depth compared to the Helix Hydro-Jet. Less foaming and the possible application of various separating media are a considerable advantage. All things considered, the new Erbejet 2 offers more options to enlarge the field of neurosurgical indications for waterjet dissection.

Brain abscess formation within an endodermal cyst of the frontal lobe: case report.

A 38-year-old man with a right frontal lobe cyst was treated by endoscopic cystoventriculostomy in 1998. Cyst capsule histology revealed surprisingly an endodermal cyst. The patient was reoperated for cyst expansion by endoscopic re-cystoventriculostomy in 2005. In 2007, the patient suffered from brain abscess formation within the cyst which was punctured. The history was positive for a dental infection. In 2008, a recurrent brain abscess in the cyst occurred. The cyst was completely resected. There was no history of trauma or sinusitis. In all, endodermal cysts may mimic a paraxial arachnoid cyst. It may predispose for recurrent brain abscess formation - especially due to bacteraemia. This report confirms earlier presentations that endodermal cysts should be resected, and endoscopic cyst opening is not sufficient.

Aperture design for the third neutron and first gamma-ray imaging systems for the National Ignition Facility.

The current construction of a new nuclear-imaging view at the National Ignition Facility will provide a third line of sight for hotspot and cold fuel imaging and the first dedicated line of sight for 4.4-MeV γ-ray imaging of the remaining carbon ablator. To minimize the effort required to hold and align apertures inside the vacuum chamber, the apertures for the two lines of sight will be contained in the same array. In this work, we discuss the system requirements for neutron and γ-ray imaging and the resulting aperture array design.

Progress on next generation gamma-ray Cherenkov detectors for the National Ignition Facility.

Fusion reaction history and ablator areal density measurements for Inertial Confinement Fusion experiments at the National Ignition Facility are currently conducted using the Gamma Reaction History diagnostic (GRH_6m). Future Gas Cherenkov Detectors (GCDs) will ultimately provide ∼100x more sensitivity, reduce the effective temporal response from ∼100 to ∼10 ps, and lower the energy threshold from 2.9 to 1.8 MeV, relative to GRH_6m. The first phase toward next generation GCDs consisted of inserting the existing coaxial GCD-3 detector into a reentrant well which puts it within 4 m of the implosion. Reaction history and ablator gamma measurement results from this Phase I are discussed here. These results demonstrate viability for the follow-on Phases of (II) the use of a revolutionary new pulse-dilation photomultiplier tube to improve the effective measurement bandwidth by >10x relative to current PMT technology; and (III) the design of a NIF-specific "Super" GCD which will be informed by the assessment of the radiation background environment within the well described here.

Streaked optical pyrometer system for laser-driven shock-wave experiments on OMEGA.

The temperature of laser-driven shock waves is of interest to inertial confinement fusion and high-energy-density physics. We report on a streaked optical pyrometer that measures the self-emission of laser-driven shocks simultaneously with a velocity interferometer system for any reflector (VISAR). Together these diagnostics are used to obtain the temporally and spatially resolved temperatures of approximately megabar shocks driven by the OMEGA laser. We provide a brief description of the diagnostic and how it is used with VISAR. Key spectral calibration results are discussed and important characteristics of the recording system are presented.

Design and fabrication of a window for the gas Cherenkov detector 3.

The gas Cherenkov detector 3 was designed at Los Alamos National Laboratory for use in inertial confinement fusion experiments at both the Omega Laser Facility and the National Ignition Facility. This instrument uses a low-Z gamma-to-electron convertor plate and high pressure gas to convert MeV gammas into UV/visible Cherenkov photons for fast optical detection. This is a follow-on diagnostic from previous versions, with two notable differences: the pressure of the gas is four times higher, and it allows the use of fluorinated gas, requiring metal seals. These changes force significant changes in the window component, having a unique set of requirements and footprint limitations. The selected solution for this component, a sapphire window brazed into a stainless steel flange housing, is described.

Design of the polar neutron-imaging aperture for use at the National Ignition Facility.

The installation of a neutron imaging diagnostic with a polar view at the National Ignition Facility (NIF) required design of a new aperture, an extended pinhole array (PHA). This PHA is different from the pinhole array for the existing equatorial system due to significant changes in the alignment and recording systems. The complex set of component requirements, as well as significant space constraints in its intended location, makes the design of this aperture challenging. In addition, lessons learned from development of prior apertures mandate careful aperture metrology prior to first use. This paper discusses the PHA requirements, constraints, and the final design. The PHA design is complex due to size constraints, machining precision, assembly tolerances, and design requirements. When fully assembled, the aperture is a 15 mm × 15 mm × 200 mm tungsten and gold assembly. The PHA body is made from 2 layers of tungsten and 11 layers of gold. The gold layers include 4 layers containing penumbral openings, 4 layers containing pinholes and 3 spacer layers. In total, there are 64 individual, triangular pinholes with a field of view (FOV) of 200 µm and 6 penumbral apertures. Each pinhole is pointed to a slightly different location in the target plane, making the effective FOV of this PHA a 700 µm square in the target plane. The large FOV of the PHA reduces the alignment requirements both for the PHA and the target, allowing for alignment with a laser tracking system at NIF.

Next generation gamma-ray Cherenkov detectors for the National Ignition Facility.

The newest generation of Gas Cherenkov Detector (GCD-3) employed in Inertial Confinement Fusion experiments at the Omega Laser Facility has provided improved performance over previous generations. Comparison of reaction histories measured using two different deuterium-tritium fusion products, namely gamma rays using GCD and neutrons using Neutron Temporal Diagnostic (NTD), have provided added credibility to both techniques. GCD-3 is now being brought to the National Ignition Facility (NIF) to supplement the existing Gamma Reaction History (GRH-6m) located 6 m from target chamber center (TCC). Initially it will be located in a reentrant well located 3.9 m from TCC. Data from GCD-3 will inform the design of a heavily-shielded "Super" GCD to be located as close as 20 cm from TCC. It will also provide a test-bed for faster optical detectors, potentially lowering the temporal resolution from the current ∼100 ps state-of-the-art photomultiplier tubes (PMT) to ∼10 ps Pulse Dilation PMT technology currently under development.

Hemoptysis as the presenting manifestation of thyroid carcinoma. A case report.

An unusual case of a 61-year-old man who had hemoptysis as the major presenting manifestation of radiation-induced thyroid carcinoma is reported. The diagnosis was made by bronchoscopic removal of a polypoid lesion that was a direct extension of tumor through the trachea. Bronchoscopy is an effective and reliable means of establishing the diagnosis in this unusual subset of patients with thyroid carcinoma invading the trachea, and should be considered as the first diagnostic procedure in a patient with a thyroid mass and hemoptysis.

[Rapid improvement in vision and visual field after olfactory groove meningioma operation]. / Rasanter Visusanstieg und Gesichtsfeldverbesserung nach Olfaktoriusmeningeomoperation.

This article reports the case of a 46-year-old female patient with a large olfactory groove meningioma (56 × 60 × 52 mm). Postoperatively, the patient rapidly experienced a significant improvement in vision and visual field, which initially was greatly impaired (initial vision 0.2 and circular impairment of the visual field of the left eye). The meningioma was resected by a frontal, osteoplastic craniotomy. Even on the sixth postoperative day, the vision and the visual field had completely recovered. An operative approach is indicated in large meningiomas targeting a complete resection.

The pancreas. Nonneoplastic alterations.

The normal development and microanatomy of the pancreas are summarized, and brief comments are made regarding current concepts of the control of exocrine functions. Pathologic alterations of acinar cells (including degranulation, nuclear changes, and cytoplasmic vacuolization) are fairly common, but they are often overlooked. Dilatation of acini, loss of acinar cells, and apparent increases in centroacinar cells and intercalated ductal cells also may occur. Changes in the larger ducts include epithelial atrophy, hyperplasia, and metaplasia; in addition, some relationships to age, ductal obstruction, and ductal carcinoma may exist. However, the majority of the alterations are nonspecific. The major types of chronic pancreatitis are illustrated, especially the irregularity of the pancreatic involvement that is so common. In an attempt to better understand the early stages of acute pancreatitis, foci of acute localized pancreatitis have also been studied.

Acinar cell carcinoma of the pancreas. A clinicopathologic study of 28 cases.

We have examined the microscopic appearance, immunohistochemical staining properties, and clinical behavior of 28 cases of acinar cell carcinoma of the pancreas. Two of the tumors occurred in children. The adult patients ranged in age from 40 to 81 years (mean, 62 years). Males greatly outnumbered females, and most of the patients were white. Presenting symptoms were nonspecific, and jaundice was infrequent. The frequently reported complications from increased serum lipase levels (i.e., arthralgias and subcutaneous fat necrosis) were present in only 16% of the patients. Grossly, the tumors were relatively circumscribed and fleshy, averaging 10.8 cm, with occasionally extensive hemorrhage and necrosis. Microscopically, the tumors were very cellular and characteristically lacked a desmoplastic stroma. Acinar, solid, trabecular, and glandular patterns of growth were identified; individual tumors were usually mixed. Nuclei were round to oval, with minimal pleomorphism and single prominent nucleoli. Mitotic activity was variable. In general the cytoplasm was moderately abundant, eosinophilic, and granular, but many of the solid tumors had cells with scanty cytoplasm. Characteristic periodic acid-Schiff-positive, diastase-resistant cytoplasmic granules were demonstrated in greater than 90% of the cases, and the butyrate esterase histochemical stain for lipase activity was positive in 73%. Immunohistochemically, there was positivity for trypsin in 100% of the cases, for lipase in 77%, for chymotrypsin in 38%, and for amylase in 31%. A minor endocrine component was recognized with antibodies against chromogranin or islet cell hormones in 42% of the tumors. Ultrastructurally, exocrine secretory features were present, with polarized cells showing microvillilined lumina, abundant rough endoplasmic reticulum, and 125-1,000-nm zymogen-like granules. In addition, many cases showed pleomorphic electron-dense granules measuring up to 3,500 nm and containing fibrillary internal structures. Follow-up information was available in 88% of the cases. Half of the patients had metastatic disease at presentation and an additional 23% subsequently developed metastases, which were usually restricted to the regional lymph nodes and liver. The mean survival for all cases was 18 months, with 1- and 3-year survivals of 57 and 26%, respectively. Patients presenting before age 60 years survived nearly twice as long as older patients did. Stage also influenced prognosis, whereas the histologic subtype of the tumors and the location within the pancreas correlated only weakly with survival.

Comparison of polymerase chain reaction from plasma and buffy coat with antigen detection and occurrence of immunoglobulin M for the demonstration of cytomegalovirus infection after liver transplantation.

We compared the value of PCR on plasma with PCR on buffy coat leukocytes, Ag assay, and the determination of IgM antibodies by ELISA for the diagnosis and follow-up of cytomegalovirus infection. Thirty patients were followed after liver transplantation (LTX). We compared the tests to assess their clinical usefulness. Fourteen of 30 (46%) patients were both positive in plasma and buffy coat PCR and Ag test. Sixteen patients were negative in both procedures. There was a 97.2% concordance between PCRs done from plasma or buffy coat. The concordance of results of PCR and Ag test in single samples was 94.3%. Discordant results were found in 5.6% of samples. Discordance was observed in the early and the late phase of CMV infection and was due to positive PCRs preceding positive Ag tests for 1-3 weeks in one-half of the patients. IgM antibodies were first observed after a median period of 8 weeks (range, 6-11 weeks) after LTX. Positive PCRs and Ag tests preceded clinical manifestation of CMV disease by a 1 week median (range, 0-3 weeks), whereas positive IgM ELISAs occurred after a median period of 2.5 weeks (range, 0-4 weeks) after the onset of CMV disease. The sensitivity and specificity of both PCR and Ag test were identical, 100% and 76%, respectively. However, for the IgM ELISA, the sensitivity was only 66%, and the specificity was 84%. In conclusion, plasma or buffy coat PCR and Ag test are equally reliable procedures for early detection and monitoring of CMV infection. PCR can become positive earlier than the Ag test, but it is technically more demanding to perform. The demonstration of IgM antibodies is of little practical help because an antibody response occurs too late in relation to infection.