Iatrogenic pharyngo-esophageal diverticulum post-anterior cervical discectomy and fusion: A case report and review of literature.

Objectives: The purpose of this study is to report a case of iatrogenic pharyngoesophageal diverticulum post-anterior cervical discectomy and fusion (ACDF) surgery, its management and management of postoperative complications. We also did a thorough review of literature about iatrogenic pharyngoesophageal diverticulum which is a rarely encountered complication occurring after a commonly performed surgery; ACDF. Methods: Here we describe a case of iatrogenic pharyngoesophageal diverticulum post-ACDF surgery. In this paper we also make comparisons to the 23 cases reported in the literature in terms of: presentations, clinical findings, management courses, and complications. This study was approved by the Institution Review Board of Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia. (Ref. no.: IRB-2023-01-473). The reported subject provided written informed consent before initiation of this study. Results: Our case is a 45-year-old male with a history of ACDF surgery 8 years ago. He presented with dysphagia and regurgitations which started 1 year after ACDF. He was labeled as a case of Zenker's diverticulum and underwent multiple failed open and endoscopic surgeries prior to presenting to us. Upon presenting to our center, barium swallow showed the pharyngoesophageal diverticulum. Patient definitive diagnosis of iatrogenic rather than Zenker's diverticulum was established intra-operatively with esophagoscopy which revealed exposed hardware inside the diverticulum. He underwent open diverticulectomy and diverticulopexy. Postoperatively he developed pharyngocutanous fistula and right vocal fold palsy, both successfully managed conservatively. Conclusion: Iatrogenic Pharyngoesophageal diverticulum is a rare complication following ACDF, however prolonged dysphagia shall warrant further investigation by contrast studies. Open diverticulectomy with muscle reinforcement is a good management modality. Due to the complicated anatomy secondary to previous operations, we recommend conservative management for patients with postoperative pharyngocutaneous fistula.

How media coverage news and global uncertainties drive forecast of cryptocurrencies returns?

This paper aims to investigate the impact of global financial, economic, and gold price uncertainty indices (VIX, EPU, and GVZ) and investor sentiment based on media coverage news on the returns of Bitcoin and Ethereum during the COVID-19 pandemic. We adopt an asymmetric framework based on the Quantile-on-Quantile approach, which examines the quantiles of the cryptocurrency returns, investor sentiment, and the various uncertainties indicators. The empirical findings suggest that the COVID-19 pandemic has significantly impacted cryptocurrency returns. Specifically, (i) the results demonstrate the predictive power of Economic Policy Uncertainty (EPU) during this period, as evidenced by a strong negative association between EPU and cryptocurrency returns across all quantiles; (ii) the correlation between cryptocurrency returns and the VIX index was negative but weak, across various quantile combinations of Ethereum and Bitcoin returns; (iii) an increase in COVID-19 news negatively affected Bitcoin returns across all quantiles; (iv) Bitcoin and Ethereum cannot be relied upon as effective hedging tools against global financial and economic uncertainty during the COVID-19 pandemic. Studying the behavior of cryptocurrency during uncertainty like pandemics is extremely important because it provides investors with insights on diversifying their portfolios and hedging their risks.

Discrete fracture network model analysis of the effects of fluid transport on the morphology of a cluster of activated fractures.

Convective transport in low-permeability rocks can be enhanced by the injection of a pressurized fluid to activate preexisting weak planes (fractures). These fractures are initially closed, but fluid-pressure-induced slippage creates void space that allows for fluid flow. The Coulomb-Mohr criterion yields a critical pressure required to open each of the fractures. Due to the intrinsic porosity of the rock, the injected fluid can flow from the fractures' surfaces to the rock matrix through a process referred to as leakoff. Following this activation mechanism, the connectivity of the cluster of activated fractures is strongly dependent on the ratio F_{N} of the standard deviation of the critical pressures to the viscous pressure drop over a fracture's length. Recently, we proposed a continuum model to predict the effects of fluid transport on the morphology of the cluster of activated fractures formed by this process over a specific intermediate range of values of F_{N} [Alhashim and Koch, J. Fluid Mech. 847, 286 (2018)JFLSA70022-112010.1017/jfm.2018.313]. In this paper, the activation process of a discrete well-connected network of preexisting fractures embedded in a highly heterogeneous rock is modeled to analyze the effects of fluid transport on the resulting cluster's morphology for a wider range of F_{N} and show how the idealized averaged equation solution arises in a discrete system. We derive a length scale ξ_{ch}, which is a function of F_{N} above which the viscous pressure drop is important. This length scale, along with the radius of the cluster R and the average separation between the preexisting fractures ξ_{0}, can be used to define distinct growth regimes where different models can be used to describe the growth dynamics and predict the connectivity of the active network. When ξ_{0}∼ξ_{ch}≪R, the cluster is well connected and a linear pressure diffusion equation can be used to describe the cluster's growth. When ξ_{ch}≫R≫ξ_{0}, a fractal network is formed by an invasion percolation process. In an intermediate regime ξ_{0}≪ξ_{ch}≪R, percolation theory relates the porosity and permeability of the network to the local fluid pressure. For this regime, we validate the predictions of the continuum theory we recently developed to describe the cluster growth on length scales larger than ξ_{ch}.

Telegram as a Tool to Supplement Online Medical Education During COVID-19 Crisis.

INTRODUCTION: Instant Messaging Applications are known for their potential to enhance learning. However, to date, there has been little investigation into the implications of the 'Telegram' application for online medical education and training. AIM: This study explores the potential benefits and disadvantages of integrating Telegram into undergraduate medical education during the COVID-19 pandemic. METHODS: An exploratory study was conducted between March and May 2020, with 203 undergraduate medical students recruited through purposive sampling. Data was collected through seven open-ended questions, followed by thematic analysis using Atlas.ti. RESULTS: Most students participating in this study reported multiple utilities of the application, including easy access to educational resources and the ability to add unlimited members, as well as files in all formats and sizes. Additionally, the application assisted students to engage with collaborative learning, maintain their wellbeing, and ensure their security. However, they also reported some drawbacks, i.e., a complex interface, information overload, and a tendency to distract them, causing time wastage. CONCLUSION: This study concludes that Telegram provides an effective mobile learning platform for medical students during the current crisis, in particular. Moreover, it offers considerably more functionalities and fewer potential drawbacks than alternative applications.

Recurrent extensive plunging ranula: A rare case.

Plunging ranula (PR) is a cystic mass presenting on the lateral side of the neck with or without a history of the usual presentation of an intraoral lesion. "PR" is recognized as an uncommon lesion that has been found predominantly in the third decade of life mostly in males. However, the exact prevalence of "PR" is not yet known. We report a rare case of an extensive PR that reached the parapharyngeal space in a 17-year-old Saudi female. The diagnosis was made when she presented to the ENT clinic with swellings in the right submandibular and right floor of the mouth. The diagnosis of "PR" with the absence of an oral lesion is very challenging and requires a detailed history, clinical examination, and radiological imaging. Different modalities of treatment have been discussed. However, the excision of ranula and the sublingual gland is the most effective way of management.