Alex Chee
University of Calgary
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Featured researches published by Alex Chee.
Respirology | 2012
David R. Stather; Paul Mac Eachern; Alex Chee; Elaine Dumoulin; Alain Tremblay
Background and objective:u2003 Endobronchial ultrasound with transbronchial needle aspiration (EBUS‐TBNA) is a pulmonary procedure that can be challenging to learn. This study aims to compare trainee EBUS‐TBNA performance during clinical procedures, following training with a computer EBUS‐TBNA simulator versus conventional clinical EBUS‐TBNA training.
Journal of Immunology | 2000
Brent Johnston; Alex Chee; Thomas B. Issekutz; Tatiana Ugarova; Alison Fox-Robichaud; Michael J. Hickey; Paul Kubes
Rats immunized with Mycobacterium butyricum in Freund’s adjuvant develop a chronic vasculitis, with large increases in leukocyte rolling and adhesion in mesenteric postcapillary venules that are significantly inhibited with an α4 integrin Ab. Using intravital microscopy to visualize chronically inflamed microvessels, we demonstrated that α4 integrin-dependent leukocyte rolling and adhesion was inhibited with a β1 integrin, but not a β7 integrin Ab. To date, VCAM-1 has been presumed to be the primary ligand for α4β1 integrin in the vasculature. However, α4β1 integrin-dependent interactions were not reduced by monoclonal or polyclonal VCAM-1 Abs or a VCAM-1 antisense oligonucleotide despite increased VCAM-1 expression in the mesenteric vasculature. To ensure that the VCAM-1 Abs were functional and used at saturating concentrations, blood from Ab-treated rats was perfused over monolayers of CHO cells transfected with rat VCAM-1. Sufficient α4 integrin or VCAM-1 Ab was present to inhibit leukocyte interactions with rat VCAM-1 by 95–100%. Under in vitro flow conditions, only mononuclear leukocytes were recruited from blood of control rats onto purified VCAM-1. However, neutrophils were also recruited onto VCAM-1 from whole blood of adjuvant-immunized animals via α4 integrin. Another ligand for α4β1 integrin is the connecting segment-1 (CS-1) region of fibronectin. An Ab to the CS-1 portion of fibronectin, which did not reduce rolling and adhesion in adjuvant arthritis animals, completely inhibited leukocyte adhesion to CS-1 under static conditions. These findings provide the first evidence that α4β1 integrin-dependent leukocyte rolling and adhesion can occur in vivo via a mechanism other than VCAM-1.
Respiration | 2013
Natasha F. Sabur; Alex Chee; David R. Stather; Paul MacEachern; Kayvan Amjadi; Christopher A. Hergott; Elaine Dumoulin; Anne V. Gonzalez; Alain Tremblay
Background: Tunneled pleural catheters (TPC) are used in the management of malignant pleural effusions (MPE), but the impact of this palliative procedure on patient quality of life (QoL) has not been well described. Objectives: To ascertain the impact of TPCs on symptoms and QoL of patients with recurrent MPE. Methods: Patients with recurrent MPE completed the EORTC QLQ-C30 and LC13 QoL questionnaires at baseline, 2 and 14 weeks; FACIT-TS-G© treatment satisfaction surveys were completed at 14 weeks. Results: A total of 82 patients were recruited. Thirty-seven patients (37/82, 45%) died prior to their 14-week follow-up appointment. Significant improvements in dyspnea at 2 weeks were demonstrated with both dyspnea scores (LC13 baseline score 64.1, 2-week score 43.7, mean change –20.4, n = 56, p < 0.001; C30 baseline score 78.9, 2-week score 46.6, mean change –32.4, n = 68, p < 0.001), as well as with the MRC score (baseline median score 4, 2-week score 3, n = 70, p < 0.001). Global health status/QoL was also significantly improved at 2 weeks (baseline score 34.1, 2-week score 46.3, mean change 12.3, n = 68, p < 0.001). Improvements in cough, fatigue and all functional scales were noted at 2 weeks. The improvements in dyspnea and global health status/QoL were maintained to 14 weeks in surviving subjects and there was further improvement in the MRC score at 14 weeks. Patients who completed the FACIT-TS-G survey demonstrated overall satisfaction with TPC treatment. Conclusions: TPCs are associated with a significant improvement in global health status, QoL and dyspnea at the 2-week time point in patients with recurrent MPE.
Current Opinion in Pulmonary Medicine | 2011
Alex Chee; Alain Tremblay
Purpose of reviewTunneled pleural catheters (TPCs) have become a popular therapeutic tool for chronic pleural effusions. Although the main indication for a TPC has been recurrent, symptomatic, malignant pleural effusion, there are increasing reports of TPC usage in other medical conditions. This article will address the utility of TPCs in malignant pleural effusions, other reported uses, potential complications and catheter maintenance. Recent findingsThe efficacy of TPCs has been well established in the setting of malignant pleural effusions and this option is now included in the guidelines addressing treatment of this condition. TPCs appear to have similar cost-effectiveness compared to chemical pleurodesis and are particularly useful in patients with trapped lung syndrome or who have shorter predicted lifespans. Attempts at bridging the benefits of pleurodesis and TPCs have been described by several groups and the recent reports have considered their use in chronic benign conditions including congestive heart failure, hepatic hydrothorax and chronic pleural infections. SummaryTPCs are an effective management strategy for symptomatic, recurrent, malignant pleural effusions. Their use as a first-line treatment is feasible and TPCs are particularly preferred for patients with trapped lung or those who are not considered good candidates for chemical pleurodesis because of short life-expectancy. There currently lacks sufficient evidence to recommend the use of TPCs in nonmalignant pleural diseases.
Respirology | 2013
Alex Chee; David R. Stather; Paul MacEachern; Simon Martel; Antoine Delage; Mathieu Simon; Elaine Dumoulin; Alain Tremblay
This study aimed to investigate the diagnostic utility of peripheral endobronchial ultrasound (pEBUS) followed by as‐needed electromagnetic navigation bronchoscopy (ENB) for sampling peripheral lung nodules.
Respirology | 2013
David R. Stather; Paul MacEachern; Alex Chee; Elaine Dumoulin; Alain Tremblay
Background and objective:u2003 Complications during advanced diagnostic bronchoscopy are rare and include: pneumothorax, bleeding, mediastinitis and lymphadenitis. Increased complications have been demonstrated in patients undergoing routine bronchoscopy procedures performed by trainees. This study aimed to determine the impact of trainees during advanced diagnostic bronchoscopy on procedure time, sedation use and complications.
Chest | 2015
Rajesh Thomas; Francesco Piccolo; Daniel Miller; Paul MacEachern; Alex Chee; Taha Huseini; Lonny Yarmus; Rahul Bhatnagar; Hans J. Lee; David Feller-Kopman; Nick A Maskell; Alain Tremblay; Y. C. Gary Lee
BACKGROUNDnIndwelling pleural catheters (IPCs) are an effective option in the management of malignant pleural effusion. Up to 14% of patients with IPCs develop symptomatic pleural loculations causing ineffective fluid drainage and breathlessness. To our knowledge, this is the first study to describe intrapleural fibrinolytic therapy for IPC-related symptomatic loculations.nnnMETHODSnAll patients who received intrapleural fibrinolytic therapy for symptomatic loculations between January 1, 2002, and June 30, 2014, in four established IPC centers were retrospectively included. Patient outcomes, treatment effectiveness, and adverse events were recorded.nnnRESULTSnSixty-six patients (mean age, 64.7 ± 14.2 years; 52% women) were included. Lung cancer (31.3%) and malignant pleural mesothelioma (20.3%) were the most common malignancies. Fibrinolytic instillation was performed in outpatient (61%) and inpatient settings. Tissue-plasminogen activator (n = 52), urokinase (n = 12), and streptokinase (n = 2) were used. The majority (69.7%) received only one fibrinolytic dose (range, one to six). Pleural fluid drainage increased in 93% of patients, and dyspnea improved in 83% following therapy. The median cumulative pleural fluid volume drained at 24 h posttreatment was 500 mL (interquartile range 300-1,034 mL). The area of opacity caused by pleural effusion on chest radiograph decreased from (mean, SD) 52% (14%) to 31% (21%) of the hemithorax (n = 13; P = .001). There were two cases of nonfatal pleural bleed (3%).nnnCONCLUSIONSnIntrapleural fibrinolytic therapy can improve pleural fluid drainage and symptoms in selected patients with IPC and symptomatic loculation, but it carries a small risk of pleural bleeding. There is significant heterogeneity in its use currently, and further studies are needed to determine patient selection and optimal dosing regimen and to define its safety profile.
Chest | 2013
Lida P. Hariri; Mari Mino-Kenudson; Matthew B. Applegate; Eugene J. Mark; Guillermo J. Tearney; Colleen L. Channick; Alex Chee; Melissa J. Suter
BACKGROUNDnSolitary pulmonary nodules (SPNs) frequently require transbronchial needle aspiration (TBNA) or biopsy to determine malignant potential, but have variable diagnostic yields. Confirming needle placement within SPNs during TBNA could significantly increase diagnostic yield. Optical coherence tomography (OCT) provides nondestructive, high-resolution, microstructural imaging with potential to distinguish SPN from parenchyma. We have developed needle-based OCT probes compatible with TBNA. Before OCT can play any significant role in guiding clinical TBNA, OCT interpretation criteria for differentiating SPN from lung parenchyma must be developed and validated.nnnMETHODSnOCT of SPN and parenchyma was performed on 111 ex vivo resection specimens. OCT criteria for parenchyma and SPN were developed and validated in a blinded assessment. Six blinded readers (two pulmonologists, two pathologists, and two OCT experts) were trained on imaging criteria in a 15-min training session prior to interpreting the validation data set.nnnRESULTSnOCT of lung parenchyma displayed evenly spaced signal-void alveolar spaces, signal-intense backreflections at tissue-air interfaces, or both. SPNs lacked both of these imaging features. Independent validation of OCT criteria by the six blinded readers demonstrated sensitivity and specificity of 95.4% and 98.2%, respectively.nnnCONCLUSIONSnWe have developed and validated OCT criteria for lung parenchyma and SPN with sensitivity and specificity > 95% in this ex vivo study. We anticipate that OCT could be a useful complementary imaging modality to confirm needle placement during TBNA to potentially increase diagnostic yield.
Respirology | 2015
David R. Stather; Alex Chee; Paul MacEachern; Elaine Dumoulin; Christopher A. Hergott; Jacob Gelberg; Eric Folch; Adnan Majid; Anne V. Gonzalez; Alain Tremblay
Little published data exist regarding the learning curve for endobronchial ultrasound‐transbronchial needle aspiration (EBUS‐TBNA). We sought to assess the improvement in skill as trainees learned EBUS‐TBNA in a clinical setting.
Respiration | 2012
David R. Stather; Paul MacEachern; Alex Chee; Alain Tremblay
Background: Clopidogrel is an oral agent commonly used for primary or secondary prevention of cardiovascular disease. It is associated with an increased risk of bleeding during some medical and surgical procedures. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a new bronchoscopic technique used to accurately biopsy intrathoracic structures during flexible bronchoscopy. It is currently unknown whether clopidogrel increases bleeding complications during EBUS-TBNA procedures. Objectives: To evaluate the safety of clopidogrel use in EBUS-TBNA by identifying consecutive cases of EBUS-TBNA procedures performed on patients taking clopidogrel. Methods: A retrospective review of a prospectively collected quality improvement database from 1,100 consecutive pulmonary procedures performed by an interventional pulmonologist (D.R.S.) at the University of Calgary from July 1st, 2007 to April 1st, 2011 was performed. Results: Twelve cases of EBUS-TBNA procedures performed on patients taking clopidogrel were identified. Mean age was 74 years (range 61–85). Seven patients (66.7%) were taking aspirin in addition to clopidogrel. There was no significant bleeding seen in any cases at the time of bronchoscopy and no additional complications were identified during follow-up (at least 4 weeks; median follow-up 3 months). Conclusions: This series of 12 cases suggests that EBUS-TBNA can be performed safely by experienced operators in patients taking clopidogrel. Nevertheless, until larger prospective studies confirm this hypothesis, proceeding to EBUS-TBNA without first withdrawing clopidogrel should only be performed in situations where the risk of short-term thrombosis is believed to outweigh the (theoretical) risk of bleeding.