Olfactory schwannomas - an enigmatic clinical entity.

Olfactory Schwannomas (OS) are a rare, benign tumour entity. Throughout literature, only few cases have been reported. We describe here a case of a 75-year-old female with a contrast enhanced mass lesion in the anterior fossa, who underwent a surgical removal and its histopathological analysis was consistent with a schwannoma. The description of the origin of this tumour is intriguing and enigmatic. Although rare, this type of tumour should always be included in the differential diagnosis of anterior fossa lesions. Further research on the pathogenesis and the natural course of OS is needed.

How to perform indexing of extravascular lung water: a validation study.

BACKGROUND: Extravascular lung water is a quantitative marker of the amount of fluid in the thoracic cavity besides the vasculature. Indexing to both predicted and actual body weight have been proposed to compare different individuals and provide a uniform range of normal. OBJECTIVE: We explored extravascular lung water measured by single-indicator transpulmonary thermodilution in a large cohort of patients without cardiopulmonary instability, in order to evaluate current and alternative indexing methods. DESIGN: Prospective, observational. SETTING: Neurosurgical ICU in a tertiary referral academic teaching hospital. PATIENTS: One hundred and one consecutive patients requiring elective brain tumor surgery and postoperative ICU surveillance. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Indexed to predicted body weight, females had a mean extravascular lung water of 9.1 (SD=3.1, range: 5-23) mL/kg and males of 8.0 (SD=2.0, range: 4-19) mL/kg (p<0.001). Values indexed to predicted body weight were inversely correlated with the patient's height (p<0.001). Indexed to the traditionally used actual body weight, data showed a significant relationship to weight (p<0.001) and gender (p<0.05). In contrast, indexing to body height presented a method without dependencies on height, weight, or gender, yielding a uniform 95% confidence interval of 218-430 mL/m. Extravascular lung water increased with positive perioperative fluid balance (p=0.04). CONCLUSIONS: Using either predicted or actual body weight for indexing extravascular lung water does not lead to independence of height, weight, and gender of the patient. Specifying a fixed range of normal or a uniform upper threshold for all patients is misleading for either method, despite widespread use. Our data suggest that indexing extravascular lung water to height is superior to weight-based methods. As we are not aware of any abnormal hemodynamic profile for brain tumor patients, we propose our findings to be a close approximation to normal values.

Modern management of rare brain metastases in adults.

Brain metastases (BM) represent the main cause of intracranial neoplasms in adults, while being relatively less common in children. Today, better treatment options of the primary malignancy lead to higher remission rates as well as prolonged stable clinical conditions. This may in part explain the increased incidence of BM. Morbidity and mortality rates in patients with malignancies deteriorate significantly in cases of metastatic involvement of the central nervous system. Nowadays, especially modern management using surgical, medical, and radiotherapeutic options for treatment of BM tends to improve survival rates and enhance quality of life. Nonetheless, almost all treatment options are considered as palliative. In this review, we outline current knowledge of the incidence, diagnostic facilities, and therapeutic management of rare BM, with consideration of the basic aspects of the primary malignancy.

Iatrogenic tension pneumothorax resulting in pneumocephalus after insertion of a ventriculoperitoneal shunt: an unusual complication.

We report the case of an iatrogenic tension pneumothorax related to the placement of a ventriculoperitoneal shunt, followed by pneumocephalus. The patient was pending cranioplasty and shunt placement after decompressive craniectomy for acute subdural hematoma and posttraumatic hydrocephalus. Facilitating the severe and potential life-threatening complication was a severe obesity of the patient as well as incorrect surgical technique.

Global end-diastolic volume acquired by transpulmonary thermodilution depends on age and gender in awake and spontaneously breathing patients.

INTRODUCTION: Volumetric parameters acquired by transpulmonary thermodilution had been repeatedly proven superior to filling pressures for estimation of cardiac preload. Up to now, the proposed normal ranges were never studied in detail. We investigated the relationship of the global end-diastolic volume (GEDV) acquired by transpulmonary thermodilution with age and gender in awake and spontaneously breathing patients. METHODS: Patients requiring brain tumor surgery were equipped prospectively with a transpulmonary thermodilution device. On postoperative day one, thermodilution measurements were performed in 101 patients ready for discharge from the ICU. All subjects were awake, spontaneously breathing, hemodynamically stable and free of catecholamines. RESULTS: Main finding was a dependence of GEDV on age and gender, height and weight of the patient. Age was a highly significant non-linear coefficient for GEDV with large inter-individual variance (p < 0.001). On average, GEDV was 131.1 ml higher in males (p = 0.027). Each cm body height accounted for 13.0 ml additional GEDV (p < 0.001). GEDV increased by 2.90 ml per kg actual body weight (p = 0.043). Each cofactor, including height and weight, remained significant after indexing GEDV to body surface area using predicted body weight. CONCLUSIONS: The volumetric parameter GEDV shows a large inter-individual variance and is dependent on age and gender. These dependencies persist after indexing GEDV to body surface area calculated with predicted body weight. Targeting resuscitation using fixed ranges of preload volumes acquired by transpulmonary thermodilution without concern to an individual patient's age and gender seems not to be appropriate.

Rare Case of Convexity Meningioma Growing into Arachnoid Cyst.

BACKGROUND: Meningioma growing into an arachnoid cyst is an extremely rare event. Only 3 cases are reported in the literature. In 2 of them, an operative procedure in or near the arachnoid cyst preceded tumor growth. CASE DESCRIPTION: We report a case of a patient requiring marsupialization of an arachnoid cyst of the middle cranial fossa. On follow-up, 3 years postoperatively he showed no signs of recurrence or tumor growth. One year later, the fourth year after surgery on the cyst, he presented with large tumor growth into the former cyst's cavity. Pathologic workup after resection revealed an atypical meningioma (World Health Organization grade II). CONCLUSIONS: We discuss the possible pathogenesis in light of the scarce published literature, as well as the differential diagnosis of this rapidly growing tumor.

Meningioma surgery in the elderly: outcome and validation of 2 proposed grading score systems.

BACKGROUND: Although population age increases, published evidence on meningioma treatment in the elderly is scarce. OBJECTIVE: In order to improve selection for surgery, we investigated our patients' collective, using 2 proposed risk assessment systems, the Clinical-Radiological Grading System (CRGS) and the SKALE score (sex, Karnofsky, American Society of Anesthesiology [ASA] score, location, edema). METHODS: We retrospectively assessed morbidity and mortality in 164 patients aged ≥ 65, operated on for an intracranial meningioma. Medical and surgical records were reviewed and analyzed. CRGS and SKALE scores were calculated. The ability of both CRGS and SKALE and all single factors to predict death within 12 months was analyzed by the use of multivariate logistic regression modeling. RESULTS: Eleven patients died (6.7%). Logistic regression for CRGS/SKALE showed a significant relationship with 12 months mortality. Age, Simpson resection grade, and sex were not significant predictors when investigated alone. In multivariate logistic regression, including all proposed factors, only concomitant disease and edema (CRGS) as well as ASA score and preoperative Karnofsky Performance Scale (SKALE) showed a significant relationship to mortality. After stepwise reduction of the full multivariate regression model to its significant terms, only concomitant disease and ASA remained significant for CRGS (P < .001) and SKALE (P = .003), respectively. CONCLUSION: Meningioma resection in the elderly is possible with some mortality. We were unable to reproduce the utility of 2 proposed grading systems for mortality prediction when extending to younger patients. In single-factor analysis, only concomitant disease and ASA score remained significant. The decision whether to operate should be taken individually. Patients with severe concomitant disease or high ASA score should be advised not to undergo surgical therapy independently from other factors.

The new aneurysm clip system for particularly complex aneurysm surgery: technical note.

BACKGROUND: Currently, there is an ongoing debate regarding the best treatment option for ruptured aneurysms. The International Subarachnoid Aneurysm Trial study suggests that an endovascular procedure is the best treatment. In some complex cases, or in patients with an additional large intracerebral hemorrhage, aneurysms require further microsurgical clipping. OBJECTIVE: We introduce a new clip system to improve clipping procedures in especially complex aneurysms. METHODS: The inverted opening mechanism of the clip in combination with the special clip applier provides the surgeon with a good overview in the operating field. The new design also enables a wider opening of the clip jaws in contrast to all other well-known titanium aneurysm clips. This should provide a better and safer application and decrease the danger of premature rupture. RESULTS: From January 2006 to July 2008, 55 aneurysms were clipped in 45 patients. The most common aneurysm location was the anterior communicating artery (20 patients) followed by the M1 segment of the middle cerebral artery (16 patients). Four patients had 2, one had 3, and one had 5 aneurysms. Two clipping procedures were performed for an arteriovenous malformation-associated aneurysm. All aneurysms were clipped without any technical complication. CONCLUSION: The use of the new clip system, especially in complex aneurysm surgery, has potential benefits because of the better surgical vision during clip application and the wider opening of the clip jaws. It is easy to handle and compatible with magnetic resonance imaging.

Pullout test with three lumbar interbody fusion cages.

STUDY DESIGN: In vitro biomechanical testing was performed on 12 cadaveric human lumbar spines. OBJECTIVE: To determine the initial dislocation resistance, as quantified by the pullout force of three different cage designs. SUMMARY OF BACKGROUND DATA: Interbody cage devices frequently are used as stand-alone cages in the surgical treatment of degenerative conditions in the lumbar spine. In contrast to the wide clinical acceptance of interbody fusion cages, there are only a few biomechanical studies of posterior pullout trials. METHODS: Cylindrical threaded cages (Ray TFC Surgical Dynamics), bullet-shaped cages (Stryker), and newly designed rectangular titanium cages with an endplate anchorage device (Marquardt) were used for posterior interbody implants. For each device, the pullout test was performed in four specimens on both sides (L3-L4). RESULTS: In the pullout test, the Stryker cages required a median pullout force of 130 N (minimum, 100 N; maximum, 220 N), as compared with the higher pullout force of the Marquardt cages (median, 605 N; minimum, 450 N; maximum, 680 N), and the Ray cages (median, 945 N; minimum, 125 N; maximum, 2230 N). CONCLUSIONS: Differences in pullout resistance were noted depending on the cage design. A cage design with threads or a hook device provides superior stability, as compared with ridges. The initial pullout resistance was highest for the Ray cages and lowest for the Stryker cages.