Publications by authors named "Megan Marsh"

8 Publications

  • Page 1 of 1

Impact of Radiation Dose on Postoperative Complications in Esophageal and Gastroesophageal Junction Cancers.

Front Oncol 2021 10;11:614640. Epub 2021 Mar 10.

Icahn School of Medicine at Mount Sinai, New York, NY, United States.

The impact of radiation prescription dose on postoperative complications during standard of care trimodality therapy for operable stage II-III esophageal and gastroesophageal junction cancers has not been established. We retrospectively reviewed 82 patients with esophageal or gastroesophageal junction cancers treated between 2004 and 2016 with neoadjuvant chemoradiation followed by resection at a single institution. Post-operative complications within 30 days were reviewed and scored using the Comprehensive Complication Index (CCI). Results were compared between patients treated with <50 Gy and ≥ 50 Gy, as well as to published CROSS study neoadjuvant chemoradiation group data (41.4 Gy). Twenty-nine patients were treated with <50 Gy (range 39.6-46.8 Gy) and 53 patients were treated with ≥ 50 Gy (range 50.0-52.5 Gy) delivered using IMRT/VMAT (41%), 3D-CRT (46%), or tomotherapy IMRT (12%). Complication rates and CCI scores between our <50 Gy and ≥ 50 Gy groups were not significantly different. Assuming a normal distribution of the CROSS data, there was no significant difference in CCI scores between the CROSS study neoadjuvant chemoradiation, <50 Gy, or ≥ 50 Gy groups. Rates of pulmonary complications were greater in the CROSS group (50%) than our <50 Gy (38%) or ≥ 50 Gy (30%) groups. In selected esophageal and gastroesophageal junction cancer patients, radiation doses ≥ 50 Gy do not appear to increase 30 day post-operative complication rates. These findings suggest that the use of definitive doses of radiotherapy (50-50.4 Gy) in the neoadjuvant setting may not increase post-operative complications.
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March 2021

Pilot Prehabilitation Program for Patients With Esophageal Cancer During Neoadjuvant Therapy and Surgery.

J Surg Res 2019 03 23;235:66-72. Epub 2018 Oct 23.

Department of Surgery, University of Colorado School of Medicine, Aurora, Colorado.

Background: Locally advanced esophageal cancer is often treated with neoadjuvant therapy followed by surgery. Many patients present with or experience clinical deconditioning during neoadjuvant therapy. Prehabilitation programs in other areas of surgery have demonstrated improved postoperative outcomes. The aims of this study were to evaluate the feasibility of a pilot prehabilitation program and determine preliminary effects on surgical and cancer-related outcomes.

Methods: A retrospective review of patients treated at a single institution with resectable esophageal cancer was performed (n = 22). Patients in the prehabilitation group received protocol-structured intervention in several clinical domains including nutrition, psychosocial support, and physical exercise.

Results: Clinical stage and comorbidities were well matched between groups. The structured prehabilitation program was feasible and well received by participants. Fewer patients required admission during neoadjuvant therapy in the prehabilitation group (27.3% versus 54.5%). Percentage weight loss during treatment was 3.0% in the prehabilitation group versus 4.3% in the control group. Compared with the control group, the prehabilitation group demonstrated 0.0% versus 18.2% 30-d postoperative readmission rate and 18.2% versus 27.3% 90-d postoperative readmission rate. There were no statistically significant differences between groups in regard to complications or mortality.

Conclusions: The pilot prehabilitation program demonstrated feasibility of implementing a structured program for patients receiving neoadjuvant therapy for esophageal cancer. Although the small population limits evaluation of statistical significance, trends in the data suggest a potential benefit of the prehabilitation program on neoadjuvant hospital admission rates, postsurgical readmission rates, and nutritional status.
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March 2019

Prothrombin Complex Concentrate Reduces Blood Product Utilization in Heart Transplantation.

Pharmacotherapy 2017 Oct;37(10):1215-1220

Cardiac Surgery, Northwestern University, Chicago, Illinois.

Background: Current practices for the reversal of warfarin before cardiac surgery include the use of vitamin K and fresh frozen plasma (FFP) to reduce the risk of bleeding. Although the 2010 International Society of Heart and Lung Transplantation guidelines acknowledge the use of prothrombin complex concentrate (PCC), there is no clear consensus on its efficacy. The objective of this study was to assess the efficacy of four-factor (4-F) PCC administration in patients requiring warfarin reversal before heart transplantation by determining blood product utilization perioperatively.

Methods: Twenty-one patients who received 4-F PCC for warfarin reversal before heart transplantation were compared to a similar cohort of 39 patients who did not receive 4-F PCC, from January 2011 to July 2015. Blood product utilization was collected retrospectively for the 24-hour preoperative, intraoperative, and 48-hour postoperative periods.

Results: Patients receiving 4-F PCC required fewer blood products in all three time periods. In the 24-hour preoperative period, 22 (56%) patients in the control group and 2 (10%) patients in the 4-F PCC groups received blood products (p<0.001). Intraoperatively, all patients received blood products. The 4-F PCC group required fewer units of packed red blood cells (median 3 vs 7 units, p<0.001) and FFP (median 4 vs 9 units, p<0.001). In the 48-hour postoperative period, 20 (51%) patients in the control group and 5 (24%) patients in the 4-F PCC group received blood products (p=0.04).

Conclusions: 4-F PCC is associated with reduced blood product utilization 24 hours preoperatively and intraoperatively. Historically, the majority of patients require FFP for warfarin reversal preoperatively. In this single-center study, a significant reduction in the need for FFP was demonstrated with the use of 4-F PCC.
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October 2017

Potential Benefits of an Integrated Electric-Acoustic Sound Processor with Children: A Preliminary Report.

J Am Acad Audiol 2017 Feb;28(2):127-140

Otologic Medical Clinic at the Hough Ear Institute, Oklahoma City, OK.

Background: A number of published studies have demonstrated the benefits of electric-acoustic stimulation (EAS) over conventional electric stimulation for adults with functional low-frequency acoustic hearing and severe-to-profound high-frequency hearing loss. These benefits potentially include better speech recognition in quiet and in noise, better localization, improvements in sound quality, better music appreciation and aptitude, and better pitch recognition. There is, however, a paucity of published reports describing the potential benefits and limitations of EAS for children with functional low-frequency acoustic hearing and severe-to-profound high-frequency hearing loss.

Purpose: The objective of this study was to explore the potential benefits of EAS for children.

Research Design: A repeated measures design was used to evaluate performance differences obtained with EAS stimulation versus acoustic- and electric-only stimulation.

Study Sample: Seven users of Cochlear Nucleus Hybrid, Nucleus 24 Freedom, CI512, and CI422 implants were included in the study.

Data Collection And Analysis: Sentence recognition (assayed using the pediatric version of the AzBio sentence recognition test) was evaluated in quiet and at three fixed signal-to-noise ratios (SNR) (0, +5, and +10 dB). Functional hearing performance was also evaluated with the use of questionnaires, including the comparative version of the Speech, Spatial, and Qualities, the Listening Inventory for Education Revised, and the Children's Home Inventory for Listening Difficulties.

Results: Speech recognition in noise was typically better with EAS compared to participants' performance with acoustic- and electric-only stimulation, particularly when evaluated at the less favorable SNR. Additionally, in real-world situations, children generally preferred to use EAS compared to electric-only stimulation. Also, the participants' classroom teachers observed better hearing performance in the classroom with the use of EAS.

Conclusions: Use of EAS provided better speech recognition in quiet and in noise when compared to performance obtained with use of acoustic- and electric-only stimulation, and children responded favorably to the use of EAS implemented in an integrated sound processor for real-world use.
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February 2017

Sensitivity of the Wisconsin Card Sorting Test (64-Card Version) versus the Tower of London (Drexel Version) for detecting executive dysfunction in children with epilepsy.

Child Neuropsychol 2018 04 3;24(3):354-369. Epub 2017 Jan 3.

g Space Coast Neuropsychology Center , Melbourne , FL , USA.

Executive function deficits are common in children and adolescents with epilepsy. Though the Wisconsin Card Sorting Task (WCST) is often considered the "gold standard" for executive function assessment, its sensitivity-particularly in the case of the 64-card version (WCST-64)-is insufficiently established in pediatric samples, including children and adolescents with epilepsy. The present investigation assesses the sensitivity of the WCST-64 in children and adolescents with epilepsy in comparison to another measure: the Tower of London - Drexel Version (TOL-DX). A total of 88 consecutively referred children and adolescents with epilepsy were administered both the WCST-64 and TOL-DX as part of a comprehensive neuropsychological evaluation. The sensitivity of WCST-64 and TOL-DX variables were established and relations with epilepsy severity measures and other executive function measures were assessed. Of the WCST-64 variables, Perseverative Responses is the most sensitive, but detected executive function impairment in only 19% of this clinically referred sample; in contrast, the TOL-DX Rule Violations detected executive function impairment in half of the sample. Further, TOL-DX performances are more strongly related to epilepsy severity variables and other executive function measures in comparison to the WCST-64. Despite its popularity amongst clinicians, the WCST-64 is not as sensitive to executive dysfunction in comparison to other measures of comparable administration time, such as the TOL-DX.
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April 2018

Benefits of Adaptive Signal Processing in a Commercially Available Cochlear Implant Sound Processor.

Otol Neurotol 2015 Aug;36(7):1181-90

*Hearts for Hearing Foundation, Oklahoma City, Oklahoma; †Speech and Hearing Department, University of North Texas, Denton, Texas; ‡Dallas Ear Institute, Dallas, Texas; §Houston Ear Research Foundation, Houston, Texas; ∥Cochlear Americas, Centennial, Colorado, U.S.A.; and ¶Cochlear Limited, Sydney, Australia.

Objective: Cochlear implant recipients often experience difficulty understanding speech in noise. The primary objective of this study was to evaluate the potential improvement in speech recognition in noise provided by an adaptive, commercially available sound processor that performs acoustic scene classification and automatically adjusts input signal processing to maximize performance in noise.

Research Design: Within-subjects, repeated-measures design.

Setting: This multicenter study was conducted across five sites in the U.S.A. and Australia.

Patients: Ninety-three adults and children with Nucleus Freedom, CI422, and CI512 cochlear implants.

Intervention: Subjects (previous users of the Nucleus 5 sound processor) were fitted with the Nucleus 6 sound processor. Performance was assessed while these subjects used each sound processor in the manufacturer's recommended default program (standard directionality, ASC + ADRO for the Nucleus 5 processor and ASC + ADRO and SNR-NR with SCAN for the Nucleus 6 sound processor). The subjects were also evaluated with the Nucleus 6 with standard directionality, ASC + ADRO and SNR-NR enabled but SCAN disabled.

Main Outcome Measures: Speech recognition in noise was assessed with AzBio sentences.

Results: Sentence recognition in noise was significantly better with the Nucleus 6 sound processor when used with the default input processing (ASC + ADRO, SNR-NR, and SCAN) compared to performance with the Nucleus 5 sound processor and default input processing (standard directionality, ASC + ADRO). Specifically, use of the Nucleus 6 at default settings resulted in a mean improvement in sentence recognition in noise of 27 percentage points relative to performance with the Nucleus 5 sound processor. Use of the Nucleus 6 sound processor using standard directionality, ASC + ADRO and SNR-NR (SCAN disabled) resulted in a mean improvement of 9 percentage points in sentence recognition in noise compared to performance with the Nucleus 5.

Conclusion: The results of this study suggest that the Nucleus 6 sound processor with acoustic scene classification, automatic, adaptive directionality, and speech enhancement in noise processing provides significantly better speech recognition in noise when compared to performance with the Nucleus 5 processor.
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August 2015

Chaste: an open source C++ library for computational physiology and biology.

PLoS Comput Biol 2013 14;9(3):e1002970. Epub 2013 Mar 14.

Computational Biology, Department of Computer Science, University of Oxford, Oxford, United Kingdom.

Chaste - Cancer, Heart And Soft Tissue Environment - is an open source C++ library for the computational simulation of mathematical models developed for physiology and biology. Code development has been driven by two initial applications: cardiac electrophysiology and cancer development. A large number of cardiac electrophysiology studies have been enabled and performed, including high-performance computational investigations of defibrillation on realistic human cardiac geometries. New models for the initiation and growth of tumours have been developed. In particular, cell-based simulations have provided novel insight into the role of stem cells in the colorectal crypt. Chaste is constantly evolving and is now being applied to a far wider range of problems. The code provides modules for handling common scientific computing components, such as meshes and solvers for ordinary and partial differential equations (ODEs/PDEs). Re-use of these components avoids the need for researchers to 're-invent the wheel' with each new project, accelerating the rate of progress in new applications. Chaste is developed using industrially-derived techniques, in particular test-driven development, to ensure code quality, re-use and reliability. In this article we provide examples that illustrate the types of problems Chaste can be used to solve, which can be run on a desktop computer. We highlight some scientific studies that have used or are using Chaste, and the insights they have provided. The source code, both for specific releases and the development version, is available to download under an open source Berkeley Software Distribution (BSD) licence at, together with details of a mailing list and links to documentation and tutorials.
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November 2013

The secrets to the success of the Rush-Larsen method and its generalizations.

IEEE Trans Biomed Eng 2012 Sep 21;59(9):2506-15. Epub 2012 Jun 21.

Solido Design Automation, Inc., Saskatoon, SK, Canada.

One of the most popular methods for solving the ordinary differential equations (ODEs) that describe the dynamic behavior of myocardial cell models is known as the Rush-Larsen (RL) method. Its popularity stems from its improved stability over integrators such as the forward Euler (FE) method along with its easy implementation. The RL method partitions the ODEs into two sets: one for the gating variables, which are treated by an exponential integrator, and another for the remaining equations, which are treated by the FE method. The success of the RL method can be understood in terms of its relatively good stability when treating the gating variables. However, this feature would not be expected to be of benefit on cell models for which the stiffness is not captured by the gating equations. We demonstrate that this is indeed the case on a number of stiff cell models. We further propose a new partitioned method based on the combination of a first-order generalization of the RL method with the FE method. This new method leads to simulations of stiff cell models that are often one or two orders of magnitude faster than the original RL method.
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September 2012