Endoscopic Surgery of Skull Base Chordomas

Objective To assess our clinical experience in treating midline intracranial pathology using minimally invasive surgical techniques.Design Retrospective chart review of patients undergoing endoscopic endonasal resection of clival chordomas.Setting Two tertiary referral centers in Australia and New Zealand.Main Outcome Measures Patients were assessed by intraoperative findings (macroscopic resection rate, tumor size, and operative complications) and clinical outcomes (residual disease, postoperative complications, recurrence rate, and mortality).Results Fourteen patients underwent endoscopic resection of clival chordomas (seven primary, seven revision) with a mean follow-up of 41.45 months (3 to 104 months). Macroscopic resection rates were 71% and 29%, respectively. Mean operative time was 386 minutes. Overall cerebrospinal fluid (CSF) leak rate was 3/14 (21%) and, using the nasoseptal flap, it was 0/5 (0%). Two patients developed late recurrence; one died of disease and one was treated with intensity modulated radiation therapy. Overall mortality was 2/14 (14%).Conclusion Endoscopic resection of clival chordomas is a safe and viable alternative to the traditional open approach. The nasoseptal flap is an excellent method of obtaining a watertight skull base closure. Furthermore, this series highlighted the fact that the primary attempt at surgery offers the best chance to achieve a total resection.     

Acinetobacter calcoaceticus-Acinetobacter baumannii complex species in clinical specimens in Singapore

This study was performed to determine the prevalence, distribution of specimen sources, and antimicrobial susceptibility of the Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) species complex in Singapore. One hundred and ninety-three non-replicate Acb species complex clinical isolates were collected from six hospitals over a 1-month period in 2006. Of these, 152 (78·7%) were identified as A. baumannii, 18 (9·3%) as 'Acinetobacter pittii' [genomic species (gen. sp.) 3], and 23 (11·9%) as 'Acinetobacter nosocomialis' (gen. sp. 13TU). Carbapenem resistance was highest in A. baumannii (72·4%), followed by A. pittii (38·9%), and A. nosocomialis (34·8%). Most carbapenem-resistant A. baumannii and A. nosocomialis possessed the bla(OXA-23-like) gene whereas carbapenem-resistant A. pittii possessed the bla(OXA-58-like) gene. Two imipenem-resistant strains (A. baumannii and A. pittii) had the bla(IMP-like) gene. Representatives of carbapenem-resistant A. baumannii were related to European clones I and II.     

Case Report: Abducens Nerve Palsy and Meningitis by Rickettsia typhi

Patients with rickettsial infection may present with encephalitis or meningitis but neurologic involvement is rare in murine typhus. Here, we report two patients with Rickettsia typhi meningitis who presented with cranial neuropathy, presumably caused by two distinct disease processes. Recognition of the disease manifestations is important because rickettsial infections are potentially associated with significant morbidity. Simple effective treatments are available.     

Taking the kidney to heart

• Growing evidence supports the role of Impella in the prevention of acute kidney injury in high‐risk percutaneous interventions (HR‐PCIs).
• The Mehran contrast‐induced nephropathy risk score may serve as a helpful risk stratification tool in discerning patients undergoing HR‐PCI who may benefit from renal protection with Impella support.
• Further research is warranted to validate this renal protection strategy.

     

Overexpression and gene amplification of both ERBB2 and EGFR in an esophageal squamous cell carcinoma revealed by fluorescence in situ hybridization,multiplex ligation‐dependent probe amplification and immunohistochemistry

EGFR and ERBB2 belong to the EGFR gene family. In esophageal squamous cell carcinomas (SCCs), amplification of EGFR or ERBB2 is usually mutually exclusive. EGFR amplification occurs in approximately 15% of SCCs, ERBB2 occurs in less than 5%. Here, we report the co‐amplification of EGFR and ERBB2 in an ulcerative and infiltrating‐type SCC that measured approximately 4.2 × 2.7 × 1.2 cm with a superficial lesion occurring in the thoracic esophagus of a 72‐year‐old man. Multiplex ligation‐dependent probe amplification using representative tumor sections showed gain of CCND1 and coincident amplification of ERBB2 or EGFR or neither. Immunohistochemistry and fluorescence in situ hybridization revealed that the tumor comprised three cancer‐cell populations: well‐differentiated SCC with high‐level ERBB2 amplification and ERBB2 overexpression, more infiltrative poorly‐differentiated SCC with high‐level EGFR amplification and EGFR overexpression, and poorly‐differentiated SCC lacking any ERBB2 or EGFR abnormality. These three populations each had low‐level CCND1 amplification and nuclear cyclin D1 overexpression. This histological topology and gene amplification combinations suggested that genetic instability first produced CCND1 amplification, and then ERBB2 or EGFR gene amplification occurred. It is further speculated that during cancer progression and clonal selection indecisive predominance of either clone caused the rare co‐amplification of ERBB2 and EGFR in a single chimeric tumor.     

A Cost-Effectiveness Analysis of Blended Versus Face-to-Face Delivery of Evidence-Based Medicine to Medical Students

BackgroundBlended learning describes a combination of teaching methods, often utilizing digital technologies. Research suggests that learner outcomes can be improved through some blended learning formats. However, the cost-effectiveness of delivering blended learning is unclear.ObjectiveThis study aimed to determine the cost-effectiveness of a face-to-face learning and blended learning approach for evidence-based medicine training within a medical program.MethodsThe economic evaluation was conducted as part of a randomized controlled trial (RCT) comparing the evidence-based medicine (EBM) competency of medical students who participated in two different modes of education delivery. In the traditional face-to-face method, students received ten 2-hour classes. In the blended learning approach, students received the same total face-to-face hours but with different activities and additional online and mobile learning. Online activities utilized YouTube and a library guide indexing electronic databases, guides, and books. Mobile learning involved self-directed interactions with patients in their regular clinical placements. The attribution and differentiation of costs between the interventions within the RCT was measured in conjunction with measured outcomes of effectiveness. An incremental cost-effectiveness ratio was calculated comparing the ongoing operation costs of each method with the level of EBM proficiency achieved. Present value analysis was used to calculate the break-even point considering the transition cost and the difference in ongoing operation cost.ResultsThe incremental cost-effectiveness ratio indicated that it costs 24% less to educate a student to the same level of EBM competency via the blended learning approach used in the study, when excluding transition costs. The sunk cost of approximately AUD $40,000 to transition to the blended model exceeds any savings from using the approach within the first year of its implementation; however, a break-even point is achieved within its third iteration and relative savings in the subsequent years. The sensitivity analysis indicates that approaches with higher transition costs, or staffing requirements over that of a traditional method, are likely to result in negative value propositions.ConclusionsUnder the study conditions, a blended learning approach was more cost-effective to operate and resulted in improved value for the institution after the third year iteration, when compared to the traditional face-to-face model. The wider applicability of the findings are dependent on the type of blended learning utilized, staffing expertise, and educational context.     

Meckel–Gruber Syndrome: a population-based study on prevalence,prenatal diagnosis,clinical features,and survival in Europe

Meckel–Gruber Syndrome is a rare autosomal recessive lethal ciliopathy characterized by the triad of cystic renal dysplasia, occipital encephalocele and postaxial polydactyly. We present the largest population-based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. The study population consisted of 191 cases of MKS identified between January 1990 and December 2011 in 34 European registries. The mean prevalence was 2.6 per 100 000 births in a subset of registries with good ascertainment. The prevalence was stable over time, but regional differences were observed. There were 145 (75.9%) terminations of pregnancy after prenatal diagnosis, 13 (6.8%) fetal deaths, 33 (17.3%) live births. In addition to cystic kidneys (97.7%), encephalocele (83.8%) and polydactyly (87.3%), frequent features include other central nervous system anomalies (51.4%), fibrotic/cystic changes of the liver (65.5% of cases with post mortem examination) and orofacial clefts (31.8%). Various other anomalies were present in 64 (37%) patients. As nowadays most patients are detected very early in pregnancy when liver or kidney changes may not yet be developed or may be difficult to assess, none of the anomalies should be considered obligatory for the diagnosis. Most cases (90.2%) are diagnosed prenatally at 14.3±2.6 (range 11–36) gestational weeks and pregnancies are mainly terminated, reducing the number of LB to one-fifth of the total prevalence rate. Early diagnosis is important for timely counseling of affected couples regarding the option of pregnancy termination and prenatal genetic testing in future pregnancies.