Alexis P. Chidi
University of Pittsburgh
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Featured researches published by Alexis P. Chidi.
Cancer Research | 2016
Samer Tohme; Hamza O. Yazdani; Ahmed B. Al-Khafaji; Alexis P. Chidi; Patricia Loughran; Kerri A. Mowen; Yanming Wang; Richard L. Simmons; Hai Huang; Allan Tsung
Risks of tumor recurrence after surgical resection have been known for decades, but the mechanisms underlying treatment failures remain poorly understood. Neutrophils, first-line responders after surgical stress, may play an important role in linking inflammation to cancer progression. In response to stress, neutrophils can expel their protein-studded chromatin to form local snares known as neutrophil extracellular traps (NET). In this study, we asked whether, as a result of its ability to ensnare moving cells, NET formation might promote metastasis after surgical stress. Consistent with this hypothesis, in a cohort of patients undergoing attempted curative liver resection for metastatic colorectal cancer, we observed that increased postoperative NET formation was associated with a >4-fold reduction in disease-free survival. In like manner, in a murine model of surgical stress employing liver ischemia-reperfusion, we observed an increase in NET formation that correlated with an accelerated development and progression of metastatic disease. These effects were abrogated by inhibiting NET formation in mice through either local treatment with DNAse or inhibition of the enzyme peptidylarginine deaminase, which is essential for NET formation. In growing metastatic tumors, we found that intratumoral hypoxia accentuated NET formation. Mechanistic investigations in vitro indicated that mouse neutrophil-derived NET triggered HMGB1 release and activated TLR9-dependent pathways in cancer cells to promote their adhesion, proliferation, migration, and invasion. Taken together, our findings implicate NET in the development of liver metastases after surgical stress, suggesting that their elimination may reduce risks of tumor relapse.
Value in Health | 2016
Alexis P. Chidi; Cindy L. Bryce; Julie M. Donohue; Michael J. Fine; Douglas Landsittel; Larissa Myaskovsky; Shari S. Rogal; Galen E. Switzer; Allan Tsung; Kenneth J. Smith
BACKGROUND Interferon-free hepatitis C treatment regimens are effective but very costly. The cost-effectiveness, budget, and public health impacts of current Medicaid treatment policies restricting treatment to patients with advanced disease remain unknown. OBJECTIVES To evaluate the cost-effectiveness of current Medicaid policies restricting hepatitis C treatment to patients with advanced disease compared with a strategy providing unrestricted access to hepatitis C treatment, assess the budget and public health impact of each strategy, and estimate the feasibility and long-term effects of increased access to treatment for patients with hepatitis C. METHODS Using a Markov model, we compared two strategies for 45- to 55-year-old Medicaid beneficiaries: 1) Current Practice-only advanced disease is treated before Medicare eligibility and 2) Full Access-both early-stage and advanced disease are treated before Medicare eligibility. Patients could develop progressive fibrosis, cirrhosis, or hepatocellular carcinoma, undergo transplantation, or die each year. Morbidity was reduced after successful treatment. We calculated the incremental cost-effectiveness ratio and compared the costs and public health effects of each strategy from the perspective of Medicare alone as well as the Centers for Medicare & Medicaid Services perspective. We varied model inputs in one-way and probabilistic sensitivity analyses. RESULTS Full Access was less costly and more effective than Current Practice for all cohorts and perspectives, with differences in cost ranging from
PLOS ONE | 2016
Shari S. Rogal; Gautham Mankaney; Viyan Udawatta; Matthew Chinman; Chester B. Good; Susan Zickmund; Klaus Bielefeldt; Alexis P. Chidi; Naudia Jonassaint; Alison Jazwinski; Obaid S. Shaikh; Christopher C.W. Hughes; Paulo Fontes; Abhinav Humar; Andrea DiMartini
5,369 to
Hpb | 2015
Zachary M. Dong; Alexis P. Chidi; Julie Goswami; Katrina Han; Richard L. Simmons; Matthew R. Rosengart; Allan Tsung
11,960 and in effectiveness from 0.82 to 3.01 quality-adjusted life-years. In a probabilistic sensitivity analysis, Full Access was cost saving in 93% of model iterations. Compared with Current Practice, Full Access averted 5,994 hepatocellular carcinoma cases and 121 liver transplants per 100,000 patients. CONCLUSIONS Current Medicaid policies restricting hepatitis C treatment to patients with advanced disease are more costly and less effective than unrestricted, full-access strategies. Collaboration between state and federal payers may be needed to realize the full public health impact of recent innovations in hepatitis C treatment.
Annals of Surgical Oncology | 2018
Patrick R. Varley; Samer Tohme; Alexis P. Chidi; Julie Goswami; Dirk J. van der Windt; David A. Geller; Allan Tsung
Depression after liver transplantation has been associated with decreased survival, but the effects of pre-transplant depression on early and late post-transplant outcomes remain incompletely evaluated. We assessed all patients who had undergone single-organ liver transplantation at a single center over the prior 10 years. A diagnosis of pre-transplant depression, covariates, and the outcomes of interest were extracted from the electronic medical record. Potential covariates included demographics, etiology and severity of liver disease, comorbidities, donor age, graft type, immunosuppression, and ischemic times. In multivariable models adjusting for these factors, we evaluated the effect of pre-transplant depression on transplant length of stay (LOS), discharge disposition (home vs. facility) and long-term survival. Among 1115 transplant recipients with a median follow-up time of 5 years, the average age was 56±11 and MELD was 12±9. Nineteen percent of the study population had a history of pre-transplant depression. Pre-transplant depression was associated with longer LOS (median = 19 vs. 14 days, IRR = 1.25, CI = 1.13,1.39), discharge to a facility (36% vs. 25%, OR 1.70,CI = 1.18,2.45), and decreased survival (HR = 1.54,CI = 1.14,2.08) in this cohort, accounting for other potential confounders. In conclusion, pre-transplant depression was significantly associated with longer transplant length of stay, discharge to a facility, and mortality in this cohort.
PLOS ONE | 2016
Shari S. Rogal; Robert M. Arnold; Michael Chapko; Barbara V. Hanusa; Ada O. Youk; Galen E. Switzer; Mary Ann Sevick; Nichole K. Bayliss; Carolyn L. Zook; Alexis P. Chidi; Obrosky Ds; Susan Zickmund
BACKGROUND Hepatobiliary and pancreatic (HPB) operations have a high incidence of post-operative nosocomial infections. The aim of the present study was to determine whether hospitalization up to 1 year before HPB surgery is associated with an increased risk of post-operative infection, surgical-site infection (SSI) and infection resistant to surgical chemoprophylaxis. METHODS A retrospective cohort study of patients undergoing HPB surgeries between January 2008 and June 2013 was conducted. A multivariable logistic regression model was used for controlling for potential confounders to determine the association between pre-operative admission and post-operative infection. RESULTS Of the 1384 patients who met eligibility criteria, 127 (9.18%) experienced a post-operative infection. Pre-operative hospitalization was independently associated with an increased risk of a post-operative infection [adjusted odds ratio (aOR): 1.61, 95% confidence interval [CI]: 1.06-2.46] and SSI (aOR: 1.79, 95% CI: 1.07-2.97). Pre-operative hospitalization was also associated with an increased risk of post-operative infections resistant to standard pre-operative antibiotics (OR: 2.64, 95% CI: 1.06-6.59) and an increased risk of resistant SSIs (OR: 3.99, 95% CI: 1.25-12.73). DISCUSSION Pre-operative hospitalization is associated with an increased incidence of post-operative infections, often with organisms that are resistant to surgical chemoprophylaxis. Patients hospitalized up to 1 year before HPB surgery may benefit from extended spectrum chemoprophylaxis.
PLOS ONE | 2017
Shari S. Rogal; Viyan Udawatta; Imo Akpan; Akshata Moghe; Alexis P. Chidi; Amit Shetty; Eva Szigethy; Klaus Bielefeldt; Andrea DiMartini
BackgroundExperiences at specialized hepatobiliary centers have demonstrated efficacy of minimally invasive liver resection, but concerns exist regarding whether these procedures would remain effective once disseminated to a broad range of clinical practices. We sought to present the first comparison of MILR and open liver resection (OLR) for primary liver malignancy from a nationally representative cancer registry.MethodsCases of liver and intrahepatic bile duct cancer were identified from the National Cancer Data Base Participant Use File. Mixed effects logistic regression and stratified Cox proportional hazards regression were used for analysis. A propensity score matched cohort was used as an alternative form of analysis to evaluate the robustness of results.ResultsA total of 3236 cases were analyzed from 2010 to 2011 with 2581 OLR (80%) and 655 MILR (20%). Of the variation in patient selection for MILR 28.5% was related to treatment at a specific treatment center; however, the proportion of MILR was similar among low-, medium-, and high-volume centers. Overall 90-day mortality was lower at high-volume centers (odds ratio [OR] 0.58; 95% confidence interval [CI] 0.40–0.85) compared with low-volume centers. MILR was similar to OLR in both 90-day mortality and overall survival (OR 0.9; 95% CI 0.62–1.10) and hazard ratio [HR] 0.88 (95% CI 0.72–1.07), regardless of treatment center volume.ConclusionsMILR for primary liver malignancy is used across a variety of practice settings, with similar outcomes to OLR. While volume is associated with short-term outcomes of liver resection as a whole, this relationship is not explained by adoption of MILR at low-volume centers.
Journal of Gastrointestinal Surgery | 2015
Samer Tohme; Julie Goswami; Katrina Han; Alexis P. Chidi; David A. Geller; Srinevas Reddy; Ana Gleisner; Allan Tsung
Hepatitis C virus (HCV) treatment has the potential to cure the leading cause of cirrhosis and hepatocellular carcinoma. However, only those deemed eligible for treatment have the possibility of this cure. Therefore, understanding the determinants of HCV treatment eligibility is critical. Given that effective communication with and trust in healthcare providers significantly influences treatment eligibility decisions in other diseases, we aimed to understand patient-provider interactions in the HCV treatment eligibility process. This prospective cohort study was conducted in the VA Pittsburgh Healthcare System. Patients were recruited after referral for gastroenterology consultation for HCV treatment with interferon and ribavirin. Consented patients completed semi-structured interviews and validated measures of depression, substance and alcohol use, and HCV knowledge. Two coders analyzed the semi-structured interviews. Factors associated with patient eligibility for interferon-based therapy were assessed using multivariate logistic regression. Of 339 subjects included in this analysis, only 56 (16.5%) were deemed eligible for HCV therapy by gastroenterology (GI) providers. In the multivariate logistic regression, patients who were older (OR = 0.96, 95%CI = 0.92–0.99, p = .049), reported concerns about the GI provider (OR = 0.40, 95%CI = 0.10–0.87, p = 0.02) and had depression symptoms (OR = 0.32, 95%CI = 0.17–0.63, p = 0.001) were less likely to be eligible. Patients described barriers that included feeling stigmatized and poor provider interpersonal or communication skills. In conclusion, we found that patients’ perceptions of the relationship with their GI providers were associated with treatment eligibility. Establishing trust and effective communication channels between patients and providers may lower barriers to potential HCV cure.
Hpb | 2016
Samer Tohme; Patrick R. Varley; Douglas Landsittel; Alexis P. Chidi; Allan Tsung
This study was designed to assess unique baseline factors associated with subsequent hospitalizations in a cohort of outpatients with cirrhosis. A cohort of 193 patients with cirrhosis was recruited from an outpatient liver disease clinic at a single, tertiary medical center. Comorbidities, prescription medications, liver disease symptoms and severity, and psychiatric and pain symptoms were assessed at baseline using validated instruments. Inflammatory markers were measured using standardized Luminex assays. Subsequent hospitalizations and the primary admission diagnoses were collected via chart review. Multivariable models were used to evaluate which baseline factors were associated with time to hospitalization and number of hospitalizations. The cohort consisted of 193 outpatients, with an average age of 58±9 and model for end-stage liver disease (MELD) score of 12±5. Over follow-up, 57 (30%) were admitted to the hospital. The factors associated with time to hospitalization included the severity of liver disease (HR/MELD point:1.10, 95% CI:1.04,1.16), ascites (HR: 1.90, 95% CI: 1.01, 3.58), baseline symptoms of depression (HR:2.34, 95% CI:1.28,4.25), sleep medications (HR:1.81, 95% CI:1.01, 3.22) and IL-6 (HR:1.43, 95% CI: 1.10, 1.84). Similarly the number admissions was significantly associated with MELD (IIR: 1.08, CI: 1.07,1.09), ascites (IIR: 4.15, CI:3.89, 4.43), depressive symptoms (IIR:1.54, CI:1.44,1.64), IL-6 (IIR:1.26, CI:1.23,1.30), sleep medications (IIR:2.74, CI:2.57, 2.93), and widespread pain (IIR: 1.61, CI: 1.50, 1.73). In conclusion, consistent with prior studies, MELD and ascites were associated with subsequent hospitalization. However, this study also identified other factors associated with hospitalization including inflammation, depressive symptoms, sleep medication use, and pain.
Journal of Surgical Research | 2014
Alexis P. Chidi; Cindy L. Bryce; Katrina Han; Z.M. Dong; David A. Geller; Allan Tsung