内镜下扩大经鼻蝶入路至斜坡区的解剖学研究

目的探索内镜下经扩大鼻蝶入路显露斜坡区的可行性,为切除斜坡区病变提供解剖学参考。方法在10例成人头部固定标本上,内镜下模拟扩大经鼻蝶手术入路显露斜坡区,观察有关显微解剖标志。结果扩大经鼻蝶内镜入路可磨除从鞍后到斜坡、枕骨大孔前缘的骨性结构;可显露斜坡区腹侧硬膜下的椎基底动脉及其分支、后交通动脉及其与大脑后动脉汇合处、动眼神经、脑干腹侧等结构。此入路的手术标志主要包括:蝶筛隐窝、蝶窦开口、视神经隆突、颈内动脉隆突与颈内动脉视神经隐窝、咽结节、枕骨大孔前缘。结论内镜下扩大经鼻蝶手术入路可充分显露鞍后-斜坡区的腹侧硬膜下结构,适用于此区病变的手术治疗。     

Extended thromboprophylaxis for medically ill patients with decreased mobility: does it improve outcomes?

Summary. Background: Duration of thromboprophylaxis beyond hospital discharge for medically ill patients has been controversial. Therefore an evaluation was made of the evidence currently available. Methods: A search was made of the Pub Med, CENTRAL and EMBASE databases for randomized controlled trials from 1966 through to 2011. Interventions included thromboprophylaxis administered over an extended period in patients hospitalized for acute medical illness with decreased level of mobility. No differentiation was made for the medication used for individual studies. The comparator included standard medical therapy and/or placebo. The efficacy outcomes assessed were a composite of asymptomatic and symptomatic deep vein thromboses (DVT), pulmonary emboli (PE) and venous thromboembolism (VTE)‐related deaths in the intervention group vs. the comparator group, as well as the safety outcomes evaluated with rates of bleeding events at the end of at least 30 days of follow‐up. The methodological quality of the studies was assessed, as was publication bias. Event rates were compared using a forest plot of relative risk (RR; 95% confidence interval (CI)) using a random effects model (Mantel‐Haenszel) between the active thromboprophylaxis and controls. Statistical analysis was carried out with Review Manager V5.1. Results: Three recent studies were included. Extended duration thromboprophylaxis reduced the combined composite event rate, RR 0.75 (0.64, 0.88). However, individual clinical endpoints were not significantly improved with extended prophylaxis: asymptomatic proximal DVT, RR 0.85 (0.68, 1.05); symptomatic DVT, RR 0.44 (0.19, 1.00); symptomatic non‐fatal PE, RR 0.80 (0.43, 1.48); VTE‐related death, RR 0.64 (0.38, 1.10). However, bleeding events were far more prevalent with extended thromboprophylaxis with major bleeds, RR 2.68 (1.78, 4.05), with a number needed to harm of 194. Conclusion: Currently available evidence does not indicate that routine administration of post‐discharge prophylaxis will be beneficial to the patients admitted for medical illness.     

In vivo and in vitro MR imaging of renal tumors: histopathologic correlation and pulse sequence optimization

Magnetic resonance (MR) imaging has given mixed results in the detection of renal masses. To identify the reasons for this and to determine the optimal pulse sequences for evaluating renal tumors, the authors imaged 12 primary renal tumors in vivo and 17 in vitro at 0.35 T. Histopathologic findings for each specimen were closely correlated with the MR images. Four of seven solid tumors imaged in vivo were isointense with surrounding normal renal parenchyma at all pulse sequences. The other three tumors were hyperintense in vivo at T2-weighted sequences. At heavily T2-weighted sequences eight solid tumors were hyperintense in vitro and four were hypointense. There was no correlation between signal intensity and specific tissue type or histologic pattern for solid tumors. The five cystic tumors were well seen both in vivo and in vitro on T2-weighted images. However, the signal intensity of the cyst fluid was an unreliable indicator of benignancy. SE MR imaging at 0.35 T has significant limitations in the detection of solid renal masses.     

Serotonin syndrome: history and risk

Summary— This review focuses on the history of investigations into the behavioural reaction resulting from excess stimulation of postsynaptic 5-hydroxytryptamine receptors and the relative risk of this occurring with different combinations of drugs. Other aspects, particularly treatment with 5-hydroxytryptamine receptor antagonists, are reviewed in a recent separate paper [44]. The first human case was in 1955 and animal work had defined the characteristic features by 1958, and established they were lessened by chlorpromazine. Substantial evidence of a 'dose-effect' relationship existed by 1984. The relative risk with different drug combinations is assessed from available evidence and argued to be strongly associated with the degree of elevation of 5-hydroxytryptamine, which is greatest following combinations of irreversible inhibitors of monoamine oxidase A and B with potent serotonin reuptake inhibitors. The various serotonergic drugs that may be implicated in serotonin syndrome are tabulated and discussed in relation to the relative risk. It is suggested that the proposed 'diagnostic criteria' for serotonin syndrome are inappropriate since there is a continuous spectrum from side effects to toxicity. The term 'serotonin syndrome' may encourage the presumption that it is an idiosyncratic response, as neuroleptic malignant syndrome is usually considered to be. The terms 'toxic serotomimetic reaction' or 'toxic serotonin syndrome' may be preferable alternatives. The differences between serotonin syndrome and neuroleptic malignant syndrome are highlighted with examples from difficult or questionable cases in the recent literature. It is proposed that more systematic national collection of toxicity data is essential in order to quantify the relative risk of serotonin syndrome with various combinations of serotonergic drugs.