Citations

Natural orifice translumenal endoscopic surgery (NOTES) is a novel surgical concept that may provide a multitasking platform for minimally invasive surgery in the 21st century. With NOTES, natural hollow organs are used to gain access to body cavities via the mouth, anus, vagina, and urethra, thereby eliminating skin incisions. Access to the body cavity through the entry portal for the NOTES procedure and closure of the portal after surgery are important treatment considerations. In this review, access and closure techniques for NOTES-related procedures are discussed. Technical descriptions for access are also described. Closure techniques using experimental and commercially available devices are also reviewed. Based on the experimental and early clinical experiences to date, the future of NOTES appears quite promising. Nonetheless, ongoing fundamental research is necessary to determine the safety and benefit of these procedures. While technical challenges are currently present, the issues are being resolved with the development of optimal instrumentation and techniques. We believe that once standardized safe and reliable access and closure techniques are established, a major shift in minimally invasive surgery will likely be inevitable.

Abstract Esophageal adenocarcinoma risk in Barrett's esophagus (BE) is increased 30- to 125-fold versus the general population. Among all BE patients, however, neoplastic progression occurs only once per 200 patient-years. Molecular biomarkers are therefore needed to risk-stratify patients for more efficient surveillance endoscopy and to improve the early detection of progression. We therefore performed a retrospective, multicenter, double-blinded validation study of eight BE progression prediction methylation biomarkers. Progression or nonprogression were determined at 2 years (tier 1) and 4 years (tier 2). Methylation was assayed in 145 nonprogressors and 50 progressors using real-time quantitative methylation-specific PCR. Progressors were significantly older than nonprogressors (70.6 versus 62.5 years; P < 0.001). We evaluated a linear combination of the eight markers, using coefficients from a multivariate logistic regression analysis. Areas under the ROC curve (AUC) were high in the 2-year, 4-year, and combined data models (0.843, 0.829, and 0.840; P < 0.001, <0.001, and <0.001, respectively). In addition, even after rigorous overfitting correction, the incremental AUCs contributed by panels based on the 8 markers plus age versus age alone were substantial (Δ-AUC = 0.152, 0.114, and 0.118, respectively) in all 3 models. A methylation biomarker–based panel to predict neoplastic progression in BE has potential clinical value in improving both the efficiency of surveillance endoscopy and the early detection of neoplasia. [Cancer Res 2009;69(10):4112–5]

Background— In contrast to the wealth of data on isolated systolic hypertension involving the systemic circulation in the elderly, much less is known about age-related change in pulmonary artery systolic pressure (PASP) and its prognostic impact in the general population. We sought to define the relationship between PASP and age, to evaluate which factors influence PASP, and to determine whether PASP is independently predictive of mortality in the community. Methods and Results— A random sample of the Olmsted County, Minn, general population (n=2042) underwent echocardiography and spirometry and was followed up for a median of 9 years. PASP was measured from the tricuspid regurgitation velocity. Left ventricular diastolic pressure was estimated with Doppler echocardiography (E/e′ ratio), and arterial stiffening was assessed from the brachial artery pulse pressure. Among 1413 subjects (69%) with measurable PASP (age, 63±11 years; 43% male), median PASP was 26 mm Hg (25th to 75th percentile, 24 to 30 mm Hg) and increased with age ( r =0.31, P <0.001). Independent predictors of PASP were age, pulse pressure, and mitral E/e′ (all P ≤0.003). Increasing PASP was associated with higher mortality (hazard ratio, 2.73 per 10 mm Hg; P <0.001). In subjects without cardiopulmonary disease (any heart failure, coronary artery disease, hypertension, diabetes mellitus, or chronic obstructive lung disease), the age-adjusted hazard ratio was 2.74 per 10 mm Hg ( P =0.016). Conclusions— We provide the first population-based evidence of age-related increase in pulmonary artery pressure, its association with increasing left heart diastolic pressures and systemic vascular stiffening, and its negative impact on survival. Pulmonary artery pressure may serve as a novel cardiovascular risk factor and potential therapeutic target.

Background . Clinicians often use validated risk models to guide treatment decisions for cardiovascular risk reduction. The most common risk models for predicting cardiovascular risk are the UKPDS, Framingham, and Archimedes models. In this article, the authors propose a model to optimize the selection of patients for statin therapy of hypercholesterolemia, for patients with type 2 diabetes, using each of the risk models. For each model, they evaluate the role of age, gender, and metabolic state on the optimal start time for statins. Method . Using clinical data from the Mayo Clinic electronic medical record, the authors construct a Markov decision process model with health states composed of cardiovascular events and metabolic factors such as total cholesterol and high-density lipoproteins. They use it to evaluate the optimal start time of statin treatment for different combinations of cardiovascular risk models and patient attributes. Results . The authors find that treatment decisions depend on the cardiovascular risk model used and the age, gender, and metabolic state of the patient. Using the UKPDS risk model to estimate the probability of coronary heart disease and stroke events, they find that all white male patients should eventually start statin therapy; however, using Framingham and Archimedes models in place of UKPDS, they find that for male patients at lower risk, it is never optimal to initiate statins. For white female patients, the authors also find some patients for whom it is never optimal to initiate statins. Assuming that age 40 is the earliest possible start time, the authors find that the earliest optimal start times for UKPDS, Framingham, and Archimedes are 50, 46, and 40, respectively, for women. For men, the earliest optimal start times are 40, 40, and 40, respectively. Conclusions . In addition to age, gender, and metabolic state, the choice of cardiovascular risk model influences the apparent optimal time for starting statins in patients with diabetes.

Object In a companion study, the authors describe the development of a new instrument named the Wireless Instantaneous Neurotransmitter Concentration System (WINCS), which couples digital telemetry with fast-scan cyclic voltammetry (FSCV) to measure extracellular concentrations of dopamine. In the present study, the authors describe the extended capability of the WINCS to use fixed potential amperometry (FPA) to measure extracellular concentrations of dopamine, as well as glutamate and adenosine. Compared with other electrochemical techniques such as FSCV or high-speed chronoamperometry, FPA offers superior temporal resolution and, in combination with enzyme-linked biosensors, the potential to monitor nonelectroactive analytes in real time. Methods The WINCS design incorporated a transimpedance amplifier with associated analog circuitry for FPA; a microprocessor; a Bluetooth transceiver; and a single, battery-powered, multilayer, printed circuit board. The WINCS was tested with 3 distinct recording electrodes: 1) a carbon-fiber microelectrode (CFM) to measure dopamine; 2) a glutamate oxidase enzyme–linked electrode to measure glutamate; and 3) a multiple enzyme–linked electrode (adenosine deaminase, nucleoside phosphorylase, and xanthine oxidase) to measure adenosine. Proof-of-principle analyses included noise assessments and in vitro and in vivo measurements that were compared with similar analyses by using a commercial hardwired electrochemical system (EA161 Picostat, eDAQ; Pty Ltd). In urethane-anesthetized rats, dopamine release was monitored in the striatum following deep brain stimulation (DBS) of ascending dopaminergic fibers in the medial forebrain bundle (MFB). In separate rat experiments, DBS-evoked adenosine release was monitored in the ventrolateral thalamus. To test the WINCS in an operating room setting resembling human neurosurgery, cortical glutamate release in response to motor cortex stimulation (MCS) was monitored using a large-mammal animal model, the pig. Results The WINCS, which is designed in compliance with FDA-recognized consensus standards for medical electrical device safety, successfully measured dopamine, glutamate, and adenosine, both in vitro and in vivo. The WINCS detected striatal dopamine release at the implanted CFM during DBS of the MFB. The DBS-evoked adenosine release in the rat thalamus and MCS-evoked glutamate release in the pig cortex were also successfully measured. Overall, in vitro and in vivo testing demonstrated signals comparable to a commercial hardwired electrochemical system for FPA. Conclusions By incorporating FPA, the chemical repertoire of WINCS-measurable neurotransmitters is expanded to include glutamate and other nonelectroactive species for which the evolving field of enzyme-linked biosensors exists. Because many neurotransmitters are not electrochemically active, FPA in combination with enzyme-linked microelectrodes represents a powerful intraoperative tool for rapid and selective neurochemical sampling in important anatomical targets during functional neurosurgery.