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Featured researches published by John Agzarian.


Journal of Toxicology and Environmental Health-part B-critical Reviews | 2008

Toward Less Confusing Terminology in Endocrine Disruptor Research

Warren G. Foster; John Agzarian

The realization that environmental contaminants interact with hormone receptors and mimic or antagonize the actions of endogenous hormones led to introduction of terms such as endocrine disruptor, endocrine disrupter, hormonally active chemicals, and hormone mimics into the scientific and lay press. Reports suggesting a link between exposure to chemicals adversely affecting the endocrine system and (1) increasing rates of hormone-dependent cancers (breast, prostate, and testicular), (2) developmental detrimental effects in the male reproductive tract, (3) falling sperm counts, and (4) endometriosis resulted in an explosion of research, regulatory actions, and policy changes aimed at better understanding the hazards posed by these chemicals with subsequent restriction in their use. With increasing concern, there is worldwide action to develop testing strategies to allow for early identification of chemicals possessing endocrine disruptor activity. However, despite an expanding literature and numerous expert panel meetings, there continues to be controversy surrounding how to best define endocrine disruptors, resulting in (1) ambiguous use of the term, (2) confusion in the literature, and (3) publication of contentious lists of chemicals purported to be endocrine disruptors. Herein it is argued in favor of a more restrictive definition with adoption of a less ambiguous term, and in favor of development of a classification system to enhance more effective communication and facilitate appropriate allocation of limited resources in this highly charged area of toxicology.


The Journal of Thoracic and Cardiovascular Surgery | 2016

Postdischarge venous thromboembolic complications following pulmonary oncologic resection: An underdetected problem

John Agzarian; Waël C. Hanna; Laura Schneider; Colin Schieman; Christian J. Finley; Yury Peysakhovich; Terri Schnurr; Dennis Nguyen-Do; Lori-Ann Linkins; James D. Douketis; Mark Crowther; Marc de Perrot; Thomas K. Waddell; Yaron Shargall

OBJECTIVES To determine the prevalence of delayed postoperative venous thromboembolism (VTE) in patients undergoing oncologic lung resections, despite adherence to current in-hospital VTE prophylaxis guidelines. METHODS Patients undergoing lung resection for malignancy in 2 tertiary-care centers were recruited between June 2013 and December 2014. All patients received guideline-based VTE prophylaxis until hospital discharge. Patients underwent computed tomography chest angiography with pulmonary embolism (PE) protocol and bilateral lower extremity venous Doppler ultrasonography at 30 ± 5 days after surgery to determine the incidence of postoperative VTE. Univariate analysis was used to compare the VTE and non-VTE groups. RESULTS A total of 157 patients were included, 45.9% were men with a mean age of 66.7 years. VTE prevalence was 12.1% with a total of 19 VTE events, including 14 PEs (8.9%), 3 deep venous thromboses (DVTs) (1.9%), 1 combined PE/DVT, and 1 massive left atrial thrombus originating from the pulmonary vein stump after pulmonary lobectomy. PE events occurred in the operated lung 64% of the time and 4 patients (21.1%) were symptomatic at diagnosis. The 30-day mortality rate of VTE events was 5.2%, with 1 patient who died secondary to massive in situ ipsilateral PE following readmission to the hospital. Univariate analysis did not demonstrate significant differences between the VTE and non-VTE populations with regard to baseline characteristics. CONCLUSIONS Despite adherence to in-hospital standard prophylaxis guidelines, VTE events are frequent, often asymptomatic, and with associated significant morbidity and mortality. More research into the potential role of predischarge screening and extended prophylaxis is warranted.


Seminars in Thoracic and Cardiovascular Surgery | 2016

The Use of Robotic-Assisted Thoracic Surgery for Lung Resection: A Comprehensive Systematic Review

John Agzarian; Christine Fahim; Yaron Shargall; Kazuhiro Yasufuku; Thomas K. Waddell; Waël C. Hanna

The primary objective of this study is to systematically review all pertinent literature related to robotic-assisted lung resection. Robotic-assisted thoracic surgery (RATS) case series and studies comparing RATS with video-assisted thoracoscopic surgery (VATS) or thoracotomy were included in the search. In accordance with preferred reporting items for systematic reviews and meta-analyses guidelines, 2 independent reviewers performed the search and review of resulting titles and abstracts. Following full-text screening, a total of 20 articles met the inclusion criteria and are presented in the review. Amenable results were pooled and presented as a single outcome, and meta-analyses were performed for outcomes having more than 3 comparative analyses. Data are presented in the following 4 categories: technical outcomes, perioperative outcomes, oncological outcomes, and cost comparison. RATS was associated with longer operative time, but did not result in a greater rate of conversion to thoracotomy than VATS. RATS was superior to thoracotomy and equivalent to VATS for the incidence of prolonged air leak and hospital length-of-stay. Oncological outcomes like nodal upstaging and survival were no different between VATS and RATS. RATS was more costly than VATS, with most of the costs attributed to capital and disposable expenses of the robotic platform. Although limited by a lack of prospective analysis, lung resection via RATS compares favorably with thoracotomy and appears to be no different than VATS. Prospective studies are required to determine if there are outcome differences between RATS and VATS.


The Annals of Thoracic Surgery | 2013

Long-Term Survival Analysis of the Canadian Lung Volume Reduction Surgery Trial

John Agzarian; John D. Miller; Sarah Daisy Kosa; Richard A. Malthaner; Lawrence Tan

BACKGROUND The Canadian Lung Volume Reduction Surgery (CLVRS) trial was a multicentered randomized controlled trial that concluded that lung volume reduction surgery improves functional status and health-related quality of life (for at least 2 years) in selected patients with advanced emphysema. METHODS This retrospective observational study assessed the long-term survival of patients enrolled in the CLVRS at 8 to 10 years after randomization. Vital statistics were gathered through telephone contact, physician records, and municipal obituaries. Survival analysis was undertaken using Kaplan-Meier and the Cox proportional hazards models. RESULTS Fifty-two patients (84% of the initial 62 patients randomized) had a median survival time of 4.11 years. A 16-month survival advantage and a 20% reduction in mortality was observed in the LVRS group as compared with the best medical care group. Although clinically meaningful, these differences were not statistically significant. CONCLUSIONS These findings echo those of other published reports and demonstrate the potential long-term benefit of LVRS in the treatment of end-stage emphysema.


Journal of Thoracic Disease | 2017

Practice patterns in venous thromboembolism (VTE) prophylaxis in thoracic surgery: a comprehensive Canadian Delphi survey.

John Agzarian; Lori-Ann Linkins; Laura Schneider; Waël C. Hanna; Christian J. Finley; Colin Schieman; Marc de Perrot; Mark Crowther; James D. Douketis; Yaron Shargall

BACKGROUND The incidence of venous thromboembolic events (VTE) after resection of thoracic malignancies can reach 15%, but prophylaxis guidelines are yet to be established. We aimed to survey Canadian practitioners regarding perioperative risk factors for VTE, impact of those factors on extended prophylaxis selection, type of preferred prophylaxis, and timing of initiation and duration of thromboprophylaxis. METHODS A modified Delphi survey was undertaken over three rounds with thoracic surgeons, thoracic anesthesiologists and thrombosis experts across Canada. Participants were asked to rate each parameter on a ten-point scale. Agreement was determined a priori as an item reaching a coefficient of variation of ≤30% (0.3), with the item then discontinued from later rounds. RESULTS In total, 72, 57 and 50 respondents participated in three consecutive rounds, respectively. Consensus was reached on previous VTE, age, cancer diagnosis, thrombophilia, poor mobilization, extended resections, and pre-operative chemotherapy as risk factors. Consensus on risk factors impacting extended prophylaxis decisions was achieved on cancer diagnosis, obesity, previous VTE and poor mobilization. With respect to perioperative prophylaxis, once daily low-molecular-weight heparin (LMWH) was the only parameter that demonstrated agreement as a common practice pattern. No agreement was achieved regarding the role of mechanical prophylaxis, unfractionated heparin (UFH) or timing of initiation of peri-operative treatment. VTE prophylaxis until discharge reached agreement but there was substantial variability regarding the role of extended prophylaxis. CONCLUSIONS There is agreement between Canadian clinicians treating patients with thoracic malignancies regarding most risk factors for VTE, but there is no agreement on timing of initiation of prophylaxis, the agents used or factors mandating usage of extended prophylaxis.


Journal of Thoracic Disease | 2017

Does the usage of digital chest drainage systems reduce pleural inflammation and volume of pleural effusion following oncologic pulmonary resection?—A prospective randomized trial

Michèle De Waele; John Agzarian; Waël C. Hanna; Colin Schieman; Christian J. Finley; Joseph Macri; Laura Schneider; Terri Schnurr; Forough Farrokhyar; Katherine Radford; Parameswaran Nair; Yaron Shargall

BACKGROUND Prolonged air leak and high-volume pleural drainage are the most common causes for delays in chest tube removal following lung resection. While digital pleural drainage systems have been successfully used in the management of post-operative air leak, their effect on pleural drainage and inflammation has not been studied before. We hypothesized that digital drainage systems (as compared to traditional analog continuous suction), using intermittent balanced suction, are associated with decreased pleural inflammation and postoperative drainage volumes, thus leading to earlier chest tube removal. METHODS One hundred and three [103] patients were enrolled and randomized to either analog (n=50) or digital (n=53) drainage systems following oncologic lung resection. Chest tubes were removed according to standardized, pre-defined protocol. Inflammatory mediators [interleukin-1B (IL-1B), 6, 8, tumour necrosis factor-alpha (TNF-α)] in pleural fluid and serum were measured and analysed. The primary outcome of interest was the difference in total volume of postoperative fluid drainage. Secondary outcome measures included duration of chest tube in-situ, prolonged air-leak incidence, length of hospital stay and the correlation between pleural effusion formation, degree of inflammation and type of drainage system used. RESULTS There was no significant difference in total amount of fluid drained or length of hospital stay between the two groups. A trend for shorter chest tube duration was found with the digital system when compared to the analog (P=0.055). Comparison of inflammatory mediator levels revealed no significant differences between digital and analog drainage systems. The incidence of prolonged post-operative air leak was significantly higher when using the analog system (9 versus 2 patients; P=0.025). Lobectomy was associated with longer chest tube duration (P=0.001) and increased fluid drainage when compared to sub-lobar resection (P<0.001), regardless of drainage system. CONCLUSIONS Use of post-lung resection digital drainage does not appear to decrease pleural fluid formation, but is associated with decreased prolonged air leaks. Total pleural effusion volumes did not differ with the type of drainage system used. These findings support previously established benefits of the digital system in decreasing prolonged air leaks, but the advantages do not appear to extend to decreased pleural fluid formation.


European Journal of Cardio-Thoracic Surgery | 2018

Colchicine for Prevention of Perioperative Atrial Fibrillation in patients undergoing lung resection surgery: a pilot randomized controlled study

Amal Bessissow; John Agzarian; Yaron Shargall; Sadeesh Srinathan; John Neary; Vikas Tandon; Christian J. Finley; Jeff S. Healey; David Conen; Reitze N. Rodseth; Shirley Pettit; William Dechert; Otto Regalado; Chinthanie Ramasundarahettige; Saleh Alshalash; Philip J. Devereaux

OBJECTIVES We carried out a pilot randomized controlled study to determine the feasibility of a large trial evaluating the impact of colchicine versus placebo on postoperative atrial fibrillation or atrial flutter (POAF) among patients undergoing lung resection surgery. METHODS Patients ≥55 years of age undergoing lung resection surgery were randomly assigned to receive colchicine 0.6 mg or placebo starting a few hours before surgery. Postoperatively, patients received colchicine 0.6 mg or placebo twice daily for an additional 9 days. Our feasibility outcomes included the period of time required to recruit 100 patients, the completeness of follow-up and compliance with the study drug. The primary efficacy outcome was POAF within 30 days of randomization. RESULTS One hundred patients were randomized (49 to colchicine and 51 to placebo) over a period of 12 months at 2 centres in Canada. All patients completed the 30-day follow-up. The mean staff time required to recruit and to follow-up each patient was 165 min. In all, 71% of patients completed the study drug course without interruption. Patient refusal to continuing taking the study drug was the main reason for permanent drug discontinuation. New POAF occurred in 5 (10.2%) patients in the colchicine group and 7 (13.7%) patients in the placebo group (adjusted hazard ratio 0.69, 95% confidence interval 0.20-2.34). CONCLUSIONS These results show the feasibility of a trial evaluating Colchicine for the prevention of perioperative Atrial Fibrillation in patients undergoing lung resection surgery. This pilot study will serve as the foundation for the large multicentre COP-AF trial.


The Journal of Thoracic and Cardiovascular Surgery | 2018

Volume-outcome relationships: Does practice really make perfect?

John Agzarian; Yaron Shargall

Division of Thoracic Surgery, Department of Surgery, Faculty of Health Sciences, St. Joseph’s Healthcare Hamilton, McMaster University, Hamilton, Ontario, Canada Disclosures: Authors have nothing to disclose with regard to commercial support. Received for publication Jan 25, 2018; accepted for publication Jan 31, 2018. Address for reprints: Yaron Shargall, MD, FRCSC, St Joseph’s Healthcare Hamilton Room, T2105, 50 Charlton Ave E, Hamilton, Ontario L8N 4A6, Canada (E-mail: [email protected]). J Thorac Cardiovasc Surg 2018;-:1-2 0022-5223/


Journal of Thoracic Disease | 2018

Beyond borders—international database collaboration in thoracic surgery

John Agzarian; Yaron Shargall

36.00 Copyright 2018 by The American Association for Thoracic Surgery https://doi.org/10.1016/j.jtcvs.2018.01.074


European Journal of Cardio-Thoracic Surgery | 2018

The effect of colchicine administration on postoperative pleural effusion following lung resection: a randomized blinded placebo-controlled feasibility pilot study

John Agzarian; Amal Bessissow; Sadeesh Srinathan; Philip J. Devereaux; John Neary; William Decher; Linda Gandy; Laura Schneider; Christian J. Finley; Colin Schieman; Waël C. Hanna; Yaron Shargall

Thoracic surgery databases continue to emerge as pillars for institutional quality improvement and research endeavors. This paper reviews the current state of the largest thoracic surgery databases: the Thoracic Surgeons General Thoracic Surgery Database (STS-GTSD) and the European Society of Thoracic Surgery Database (ESTSD). In addition, we utilize these as a platform to evaluate the role and key ingredients for successful international database collaborations. Ultimately, collaborative efforts among large databases unify research efforts, foster cohesion, serve as benchmarks for quality improvement locally, nationally and internationally, promote comparative innovation, and ultimately improve patient outcomes.

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Yaron Shargall

St. Joseph's Healthcare Hamilton

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Laura Schneider

St. Joseph's Healthcare Hamilton

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Philip J. Devereaux

Population Health Research Institute

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Amal Bessissow

McGill University Health Centre

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