Use of the VerifyNow point of care assay to assess the pharmacodynamic effects of loading and maintenance dose regimens of prasugrel and ticagrelor.

Prasugrel and ticagrelor are potent oral platelet P2Y12 inhibitors and are recommended over clopidogrel in patients with acute coronary syndrome (ACS). Oral platelet P2Y12 inhibitors are characterized by varying degrees of pharmacodynamic response profiles as assessed by a variety of commercially available assays. Because of its ease of use, rapid turnaround times and ability to provide results specific to P2Y12 inhibitory effects, VerifyNow has emerged as one of the most commonly utilized platelet function assays. However, reference ranges with VerifyNow have been reported mainly for clopidogrel and there has not yet been any study specifically conducted to provide the expected on treatment reference ranges following administration of prasugrel and ticagrelor. This was a prospective single center investigation conducted in 120 patients with ACS who were treated with prasugrel or ticagrelor as per standard of care. Patients who underwent percutaneous coronary interventions (PCI) were treated with a loading dose of prasugrel (60 mg) or ticagrelor (180 mg), and patients who were on maintenance therapy were taking prasugrel (10 mg qd or 5 mg qd) or ticagrelor (90 mg bid). Platelet function testing was performed using the VerifyNow™ PRUTest™. The overall range of PRUTest values was lower than that observed in studies of patients treated with clopidogrel. The use of a maintenance dose regimen had a wider range of PRUTest values compared to the use of a loading dose for both prasugrel (1-179 vs. 2-128) and ticagrelor (1-196 vs. 1-177). The average PRUTest values in patients on prasugrel and ticagrelor maintenance dosing were 20% and 9% higher those observed in patients treated with a loading dose. PRUTest results following loading dose administration were very similar between drugs, but were 20% higher with prasugrel compared with ticagrelor during maintenance dosing. This study establishes expected PRUTest ranges for patients taking loading and maintenance doses of prasugrel and ticagrelor.Clinical Trial Registration http://www.clinicaltrials.gov Unique Identifier: NCT04492423, registered July 2020 retrospectively registered.

Intraoperative use of optical coherence tomography to differentiate normal and diseased thyroid and parathyroid tissues from lymph node and fat.

The purpose of this study is twofold: (1) to determine the feasibility of optical coherence tomography (OCT) to differentiate normal and diseased tissue of the neck region intraoperatively and (2) to evaluate how accurately a cohort of test subjects can identify various tissue types when shown a sample set of OCT images. In this in vivo, prospective, single institutional study, an OCT imaging system (Niris, Imalux, Cleveland, OH) was used to image parathyroid, thyroid, lymph node, and fat tissue in 76 patients during neck surgery. Biopsies were performed for comparison of OCT images with histology in select cases (n = 20). Finally, a group of either surgeons or scientists familiar with OCT (n = 17) were shown a sample of OCT images and asked to identify the tissue. A total of 437 OCT images were analyzed, and characteristic features of each tissue type were identified. OCT demonstrated distinct differences in structural architecture and signal intensity that allows differentiation between thyroid and parathyroid tissues, lymph nodes, and fat. OCT images were also compared with histology with good correlation. There was no difference in correctly identifying OCT-imaged tissue type between surgeons and scientists. This study is the first in vivo OCT imaging study to evaluate both normal and diseased tissues that may be encountered during neck surgery. OCT has the potential to become a valuable intraoperative tool to differentiate diseased and normal thyroid tissue intraoperatively to obtain an "optical biopsy" in real time without fixation, staining, or tissue resection.

Imaging vibrating vocal folds with a high speed 1050 nm swept source OCT and ODT.

Vocal fold vibration is vital in voice production and the correct pitch of speech. We have developed a high speed functional optical coherence tomography (OCT) system with a center wavelength of 1050 nm and an imaging speed of 100,000 A-lines per second. We imaged the vibration of an ex-vivo swine vocal fold. At an imaging speed of 100 frames per second, we demonstrated high quality vocal fold images during vibration. Functional information, such as vibration frequency and vibration amplitude, was obtained by analyzing the tissue surface during vibration. The axial direction velocity distribution in the cross-sectional images of the vibrating vocal folds was obtained with the Doppler OCT. The quantitative transverse direction velocity distribution in the cross-sectional images was obtained with the Doppler variance images.

Transoral laser microsurgery for laryngeal cancer: a primer and review of laser dosimetry.

Transoral laser microsurgery (TLM) is an emerging technique for the management of laryngeal and other head and neck malignancies. It is increasingly being used in place of traditional open surgery because of lower morbidity and improved organ preservation. Since the surgery is performed from the inside working outward as opposed to working from the outside in, there is less damage to the supporting structures that lie external to the tumor. Coupling the laser to a micromanipulator and a microscope allows precise tissue cutting and hemostasis; thereby improving visualization and precise ablation. The basic approach and principles of performing TLM, the devices currently in use, and the associated dosimetry parameters will be discussed. The benefits of using TLM over conventional surgery, common complications and the different settings used depending on the location of the tumor will also be discussed. Although the CO(2) laser is the most versatile and the best-suited laser for TLM applications, a variety of lasers and different parameters are used in the treatment of laryngeal cancer. Improved instrumentation has lead to an increased utilization of TLM by head and neck cancer surgeons and has resulted in improved outcomes. Laser energy levels and spot size are adjusted to vary the precision of cutting and amount of hemostasis obtained.

Semi-resonant operation of a fiber-cantilever piezotube scanner for stable optical coherence tomography endoscope imaging.

A forward-view optical coherence tomography (OCT) scanning catheter has been developed based on a fiber-cantilever piezotube scanner by using a semi-resonant scan strategy for a better scan performance. A compact endoscope catheter was fabricated by using a tubular piezoelectric actuator with quartered electrodes in combination with a resonant fiber cantilever. A cantilever weight was attached to the fiber cantilever to reduce the resonance frequency down to 63 Hz, well in the desirable range for Fourier-domain OCT. The resonant-cantilever scanner was driven at semi-resonance frequencies that were well out of the resonance peak but within a range of partial resonance. This driving strategy has been found to minimize the phase difference between the two scan axes for a better scan stability against environmental perturbations as well as for a driving simplicity. By driving the two axes at slightly different frequencies, a low-order Lissajous pattern has been obtained for a 2D area scan. 3D OCT images have been successfully acquired in an acquisition time of 1.56 seconds for a tomogram volume of 2.2 × 2.2 × 2.1 mm(3). They were reconstructed without any scan calibration by extracting the scan timing from the image data. In addition, it has been found that the Lissajous scan strategy provides a means to compensate the relative axial motion of a sample for a correct imaged morphology.

Optical coherence tomography of cholesteatoma.

OBJECTIVES: To image cholesteatoma using optical coherence tomography (OCT) and correlate the results with clinical findings and conventional observations obtained using binocular microscopy and histology. OCT is a high-resolution optical imaging modality that generates cross-sectional images of turbid media, such as tissue with resolution approaching that of light microscopy. OCT relies on intrinsic differences in tissue optical properties for image contrast. STUDY DESIGN: In vivo prospective clinical study. SETTING: University Medical Center. PATIENTS: Patients with cholesteatoma undergoing otologic surgery. INTERVENTION: Using a commercial OCT imaging system, we obtained cross-sectional images (resolution, approximately 10 microm; depth penetration, approximately 1 mm) of cholesteatomas. MAIN OUTCOME MEASURES: Images are obtained by raster scanning a single mode fiber across the interior of the probe. The imaging probe is sterilized and inserted into the middle ear or mastoid under microscopic guidance, and still images of the middle ear or mastoid mucosa and cholesteatoma when present were obtained. RESULTS: OCT images of cholesteatomas demonstrate differences in signal intensity, which are distinct from those of normal or inflamed middle ear/mastoid mucosa. Identification of keratin in cholesteatoma, even if very thin, distinguished it from inflamed mucosa. CONCLUSION: This is the first study that systematically used OCT to image cholesteatoma during otologic surgery. Cholesteatomas can be distinguished from normal or inflamed adjacent mucosa.

Optical coherence tomography of the larynx using the Niris system.

OBJECTIVES: To present our experience using the first commercially available optical coherence tomography (OCT) device for use in the head, neck, and upper aerodigestive tract and to determine the feasibility and efficacy of this system in comparison with our previous experience using other research OCT systems. METHODS: Using the Niris OCT imaging system (Imalux, Cleveland, OH), we obtained OCT images of benign and premalignant laryngeal disease in 33 patients undergoing surgical head and neck endoscopy. This imaging system has a spatial depth resolution of 10 to 20 mum and a depth scanning range of 2.2 mm, obtaining images of 200 x 200 pixels at a maximum frame rate of 0.7 Hz. The scanning mechanism of the device is located at the distal end of a flexible probe that is placed in contact or near-contact with the area of interest. The tip of the probe was inserted through a rigid laryngoscope, and still images were obtained. RESULTS: OCT images of arytenoids, aryepiglottic folds, piriform sinus, epiglottis, and true and false vocal cords were obtained. In patients whose OCT images were taken from normal tissue, the normal microstructures were clearly identified, as well as disruption of the latter in malignant pathologies. CONCLUSIONS: The device can easily be incorporated into the operating room and requires minimal set-up and staff to operate. OCT imaging with this device potentially offers an efficient, quick, and reliable imaging modality in guiding surgical biopsies, intraoperative decision making, and therapeutic options of various laryngeal pathologies and premalignant disease.

[Optical coherence tomography applications in otolaryngology]. / Aplicaciones de la tomografía de coherencia óptica en otorrinolaringología.

Optical coherence tomography is a novel imaging technique providing high-resolution bidimensional images of tissue microstructures. Several studies have been published on the use of this technique in different fields of medicine, particularly ophthalmology. There are very few studies in the field of otolaryngology. This paper presents various applications of optical coherence tomography in the different sub-specialties of otolaryngology, as well as the benefits of this technique over traditional diagnostic methods.

Aplicaciones de la tomografía de coherencia óptica en otorrinolaringología / Optical coherence tomography applications in otolaryngology

La tomografía de coherencia óptica es una técnica de imagen innovadora con la cual se pueden obtener imágenes en dos dimensiones de alta resolución sobre la microestructura de los tejidos. Hoy día hay varios estudios sobre el uso de esta técnica en distintas ramas de la medicina, sobre todo en oftalmología. Sin embargo, poco se ha estudiado en la otorrinolaringología. En este trabajo presentamos los diferentes usos de la tomografía de coherencia óptica en los distintos campos de la otorrinolaringología, así como sus beneficios sobre métodos convencionales de diagnóstico (AU)

Optical coherence tomography is a novel imaging technique providing high-resolution bidimensional images of tissue microstructures. Several studies have been published on the use of this technique in different fields of medicine, particularly ophthalmology. There are very few studies in the field of otolaryngology. This paper presents various applications of optical coherence tomography in the different sub-specialties of otolaryngology, as well as the benefits of this technique over traditional diagnostic methods (AU)

Office-based dynamic imaging of vocal cords in awake patients with swept-source optical coherence tomography.

Optical coherence tomography (OCT) is an evolving noninvasive imaging modality that has been used to image the human larynx during surgical endoscopy. The design of a long gradient index (GRIN) lens-based probe capable of capturing images of the human larynx by use of swept-source OCT during a typical office-based laryngoscopy examination is presented. In vivo OCT imaging of the human larynx is demonstrated with a rate of 40 frames per second. Dynamic vibration of the vocal folds is recorded to provide not only high-resolution cross-sectional tissue structures but also vibration parameters, such as the vibration frequency and magnitude of the vocal cords, which provides important information for clinical diagnosis and treatment, as well as fundamental research of the voice itself. Office-based OCT is a promising imaging modality to study the larynx for physicians in otolaryngology.

[Evaluation of the symptomatology and quality of life in functional dyspepsia before and after Helicobacter pylori eradication treatment]. / Evaluación de la sintomatología y calidad de vida en la dispepsia funcional antes y después de tratamiento de erradicación de H. pylori.

BACKGROUND: Whether H. pylori infection plays a role in FD is ill defined; however, it is recommended to prescribe eradication treatment in patients with dyspepsia without alarm symptoms. Results of this advice are controversial, principally due to absence of instruments that provide an objective measure of changes in symptoms and quality of life. OBJECTIVE: Our aim was to evaluate significant changes in symptom severity and quality of life in patients with functional dyspepsia (FD) following Helicobacter pylori (H. pylori) eradication treatment. METHODS: We conducted an open clinical trial in adult patients with FD who were H. pylori-positive by means of 14C breath test. Treatment consisted of 2 weeks on lanzoprazole, amoxicillin, and clarithromycin. Score change on the severity of dyspepsia assessment (SODA) test instrument was used to evaluate modifications in symptom severity and quality of life. RESULTS: One hundred patients were included in this trial; treatment compliance was observed in 77% of these, while cure of H. pylori infection was obtained in 82.7% of patients. Only 11.7% displayed absence of dyspepsia symptoms and improvement in quality of life. No significant changes were obtained in global assessment nor in pain, or symptoms in health perception quality of life when initial SODA scores were compared with after-treatment results. CONCLUSIONS: There was no improvement of FD symptoms or quality of life after H. pylori eradication treatment.