Vinay Kansal | University of Saskatchewan (original) (raw)

Papers by Vinay Kansal

Endophthalmitis, a potentially devastating inflammatory condition of the vitreous and anterior ch... more Endophthalmitis, a potentially devastating inflammatory condition of the vitreous and anterior chamber, can be either noninfectious or infectious. Infectious endophthalmitis is classified as exogenous or endogenous. Exogenous endophthalmitis occurs secondary to violation of the eye wall as a result of ocular surgery or trauma, with subsequent intraocular microbial inoculation. Endogenous endophthalmitis, which is less frequent, occurs via hematogenous spread of microorganisms to the eye from systemic infection, often in immunocompromised patients. Common infectious foci include meningitis, endocarditis, indwelling catheters, and skin wounds. A 56-year-old male presented with a 2-day history of new floaters in the right eye. Ocular history was significant for surgical repair of a complex rhegmatogenous retinal detachment of the left eye, leading to a blind, painful eye, for which he underwent evisceration 6 weeks prior to developing floaters in his right eye. Systemic review revealed...

Journal of Refractive Surgery Case Reports

International Journal of Keratoconus and Ectatic Corneal Diseases

Aim: Corneal collagen cross-linking (CCL) is a procedure that exposes the cornea to ultraviolet l... more Aim: Corneal collagen cross-linking (CCL) is a procedure that exposes the cornea to ultraviolet light and/or riboflavin to halt the progression of corneal ectatic disease. Currently, most investigations using Fourier-transform infrared spectroscopy (FTIR) of corneal changes following CCL focus on corneal ultrastructure, and not on changes at the molecular level. The aim of this study was to investigate the temporal and spatial separation of corneal collagen linkages that underlie the success of CCL. Materials and methods: Controlled experimental trial. Pairs of donor globes from five patients (n = 10) were divided into interventional and control groups. Interventional group corneas (n = 5) were exposed to riboflavin 0.1% and ultraviolet-A (UVA) light according to the modified Dresden protocol, harvested, cryo-microtomed, and placed on glass slides. Control group corneas (n = 5) underwent cryo-microtoming without CCL. Molecular changes were imaged using the synchrotron mid-infrared beamline at the Canadian Light Source. Results: Fourier-transform infrared spectroscopy imaging of total protein, integrated area under the amide I band from 1,700 to 1,600 cm − 1 , FTIR imaging of collagen triple helix structures, second-derivative intensity as 1,666 cm − 1 , and FTIR imaging of aggregated proteins, secondderivative intensity as 1,625 cm − 1 detected no difference in intramolecular cross-links between the interventional and control corneas. The secondary structure of collagen was neither significantly altered nor was their evidence of aggregation or denaturation within the cornea. Conclusion: Our data suggest that intramolecular cross-linking does not play a major role in CCL and that it is more likely an increase in intermolecular linkages that accounts for increased corneal strength. Clinical significance: An increase in intermolecular linkages likely accounts for the increased corneal strength observed following CCL. We hope that these results will guide future work to optimize techniques for CCL.

Clinical and Investigative Medicine

Purpose: The impact of cardiology fellows (CFs) and interventional cardiology fellows (ICFs) on p... more Purpose: The impact of cardiology fellows (CFs) and interventional cardiology fellows (ICFs) on patient radiation and contrast exposure during diagnostic coronary angiography and percutaneous coronary intervention is unknown. Methods: Between 2011 and 2014, 16,175 cases were retrospectively assessed involving 27 CFs, 22 ICFs and 24 staff as primary operators. Results: During diagnostic coronary angiography, ICFs administered the lowest radiation dose (5,648±5,523 cGy*cm2; 1.30 ± 1.27 mSv)—achieving 22% less radiation than the staff (6,889±4,294 cGy*cm2; 1.58 ± 0.99 mSv) and 36% less than CFs (7,700±6,751 cGy*cm2; 1.77 ± 1.55 mSv) (p<0.01). When adjusted for access site, CFs administered more radiation than either the ICFs or staff. However, differences between ICFs and staff were exclusively observed during transradial procedures (p<0.01). With regards to contrast administration, ICFs administered less contrast (126.3 ± 57.6 mL) than either CFs (130±52.4 mL) or staff (132.7±47...

Clinical Ophthalmology

Background: Glaucoma surgical management has evolved significantly with the introduction of minim... more Background: Glaucoma surgical management has evolved significantly with the introduction of minimally invasive glaucoma surgery. Our aim was to evaluate trends in Canadian glaucoma surgery billing code usage as a surrogate index of the current impact of this new technology in Canada's publicly funded health-care system. Methods: Retrospective administrative health records analysis of all patients who underwent a publicly funded glaucoma filtration procedure from January 2003 to December 2016 in the 6 largest Canadian provinces. The frequency of glaucoma-related procedures was adjusted against primary open-angle glaucoma prevalence data. Frequency of all glaucoma filtration procedures with and without implantation of a drainage device in each province per year is reported. Results: Nationwide, glaucoma filtration procedures per 1000 primary open-angle glaucoma patients per year remained constant, with increased drainage device implantation over time (P<0.0001). Ontario and Nova Scotia mirrored the overall population. British Columbia and Saskatchewan showed increased rates of glaucoma filtration surgery, with increased drainage device implantations. In Quebec, overall filtration surgery decreased, while the rate of device implantation increased (p<0.0001). Alberta showed a decline in filtration surgery and device implantations from 2003 to 2008, and then increased thereafter. Conclusion: Over the study period, there was a distinct trend towards billing code usage for implanted devices. Challenges encountered during this investigation highlight the need for identifiers in provincial health databases to accommodate the introduction of novel technologies. The absence of specific billing codes for newer technologies prevents accurate analyses of impact, utilization, efficacy and cost implications in contemporary patient management.

Seminars in Ophthalmology

Journal of Vascular Surgery

Canadian Journal of Ophthalmology

Clinical Ophthalmology

Purpose: To develop and validate neural network (NN) vs logistic regression (LR) diagnostic predi... more Purpose: To develop and validate neural network (NN) vs logistic regression (LR) diagnostic prediction models in patients with suspected giant cell arteritis (GCA). Design: Multicenter retrospective chart review. Methods: An audit of consecutive patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at 14 international medical centers. The outcome variable was biopsy-proven GCA. The predictor variables were age, gender, headache, clinical temporal artery abnormality, jaw claudication, vision loss, diplopia, erythrocyte sedimentation rate, C-reactive protein, and platelet level. The data were divided into three groups to train, validate, and test the models. The NN model with the lowest false-negative rate was chosen. Internal and external validations were performed. Results: Of 1,833 patients who underwent TABx, there was complete information on 1,201 patients, 300 (25%) of whom had a positive TABx. On multivariable LR age, platelets, jaw claudication, vision loss, log C-reactive protein, log erythrocyte sedimentation rate, headache, and clinical temporal artery abnormality were statistically significant predictors of a positive TABx (P#0.05). The area under the receiver operating characteristic curve/Hosmer-Lemeshow P for LR was 0.867 (95% CI, 0.794, 0.917)/0.119 vs NN 0.860 (95% CI, 0.786, 0.911)/0.805, with no statistically significant difference of the area under the curves (P=0.316). The misclassification rate/false-negative rate of LR was 20.6%/47.5% vs 18.1%/30.5% for NN. Missing data analysis did not change the results. Conclusion: Statistical models can aid in the triage of patients with suspected GCA. Misclassification remains a concern, but cutoff values for 95% and 99% sensitivities are provided (https://goo.gl/THCnuU).

European Journal of Vascular and Endovascular Surgery

WHAT THIS PAPER ADDS Late open surgical conversion following endovascular aneurysm repair is asso... more WHAT THIS PAPER ADDS Late open surgical conversion following endovascular aneurysm repair is associated with significant morbidity and mortality. Although endograft preservation may be preferentially offered as a less invasive alternative to high risk patients requiring open surgical conversion, significant mortality was identified with this procedure. Adherence to device instructions for use (IFU) is markedly lower among EVARs requiring open surgical conversion than uncomplicated cases. There was a trend for decreasing interval to conversion; an association with liberalisation of EVAR outside of IFU is possible, but cannot be concluded from this study. Introduction: Late open surgical conversion following endovascular aneurysm repair (EVAR) may occur more frequently after performing EVAR in anatomy outside the instructions for use (IFU). This study reviews predictors and outcomes of late open surgical conversion for failed EVAR. Methods: This retrospective cohort study reviewed all EVARs performed at the Ottawa Hospital between January 1999 and May 2015. Open surgical conversions >1 month post EVAR were identified. Variables analysed included indication for conversion, pre-intervention AAA anatomy, endovascular device and configuration, operative technique, re-interventions, complications, and death. Results: Of 1060 consecutive EVARs performed, 16 required late open surgical conversion. Endografts implanted were Medtronic Talent (n ¼ 8, 50.0%), Medtronic Endurant (n ¼ 3, 18.8%), Cook Zenith (n ¼ 4, 25.0%), and Terumo Anaconda (n ¼ 1, 6.2%). Eleven grafts were bifurcated (68.8%), five were aorto-uni-iliac (31.2%). The median time to open surgical conversion was 3.1 (IQR 1.0e5.2) years. There was no significant difference in pre-EVAR rupture status (1.4% elective, 2.1% ruptured, p ¼ .54). Indications for conversion included: Type 1 endoleak with sac expansion (n ¼ 4, 25.0%), Type 2 endoleak with expansion (n ¼ 2, 12.5%), migration (n ¼ 3, 18.8%), sac expansion without endoleak (n ¼ 2, 12.5%), graft infection (n ¼ 3, 18.8%), rupture (n ¼ 2, 12.5%). Nine patients (56.2%) underwent stent graft explantation with in situ surgical graft reconstruction, seven had endograft preserving open surgical intervention. The 30 day mortality was 18.8% (n ¼ 3, all of whom having had endograft preservation). Ten patients (62.5%) suffered major in hospital complications. One patient (6.5%) required postconversion major surgical re-intervention. IFU adherence during initial EVAR was 43.8%, versus 79.0% (p < .01) among uncomplicated EVARs. Conclusions: Open surgical conversion following EVAR results in significant morbidity and mortality. IFU adherence of EVARs later requiring open surgical conversion is markedly low. More data are required to elucidate the impact of increasing liberalisation of EVAR outside of IFU.

Ophthalmology, Jan 16, 2018

To determine whether differences between eyes in axial length (AL) and corneal power (K) on optic... more To determine whether differences between eyes in axial length (AL) and corneal power (K) on optical biometry are predictive of refractive outcomes. Retrospective cohort study. A total of 729 patients (1458 eyes) who underwent bilateral phacoemulsification at TLC (Mississauga, Ontario, Canada) from September 2013 to August 2015. We compared the proportion of patients having >0.5 diopters (D) of refractive error from target stratified by interocular axial length differences (IALDs) and interocular K differences (IKDs) between eyes as measured by optical biometry (IOL-Master, Carl Zeiss Meditec, Oberkochen, Germany). Analysis was repeated for 0.25 D or 1.0 D targets and for patients with uncorrected visual acuity (UCVA) >0.3 logarithm of the minimum angle of resolution (logMAR) postoperatively. Proportions, odds ratios (ORs), and corresponding 95% confidence intervals (CIs) were computed using generalized estimating equations to account for within-patient correlation. Some 79.1% ...

Canadian journal of ophthalmology. Journal canadien d'ophtalmologie, 2018

Temporal artery biopsy (TAB) is the gold standard for confirming the diagnosis of giant cell arte... more Temporal artery biopsy (TAB) is the gold standard for confirming the diagnosis of giant cell arteritis (GCA) when positive. However, the clinical significance of healed/healing (HH) arterial injury on TAB is not well understood. The purpose of this study was to evaluate the clinical significance of this finding on TAB by determining its association with seromarkers typically predictive of GCA. Single-centre, retrospective, investigational cohort study. A total of 385 consecutive TABs for clinical suspicion of GCA between January 2009 and January 2016. Elevations in erythrocyte sedimentation rate, C-reactive protein, and platelet count were compared between patients with negative TAB, GCA-positive TAB, and HH arterial injury using statistical trend testing. Odds ratios of seromarker elevations for HH arterial injury versus GCA were calculated. Seventy-six GCA-positive, 69 HH, and 240 negative TABs were identified. Mantel-Haenszel tests of trend indicated that platelets >400 000/µL...

PloS one, 2018

Early detection, monitoring and understanding of changes in the retina are central to the diagnos... more Early detection, monitoring and understanding of changes in the retina are central to the diagnosis of glaucomatous optic neuropathy, and vital to reduce visual loss from this progressive condition. The main objective of this investigation was to compare glaucoma diagnostic accuracy of commercially available optical coherence tomography (OCT) devices (Zeiss Stratus, Zeiss Cirrus, Heidelberg Spectralis and Optovue RTVue, and Topcon 3D-OCT). 16,104 glaucomatous and 11,543 normal eyes reported in 150 studies. Between Jan. 2017 and Feb 2017, MEDLINE®, EMBASE®, CINAHL®, Cochrane Library®, Web of Science®, and BIOSIS® were searched for studies assessing glaucoma diagnostic accuracy of the aforementioned OCT devices. Meta-analysis was performed pooling area under the receiver operating characteristic curve (AUROC) estimates for all devices, stratified by OCT type (RNFL, macula), and area imaged. 150 studies with 16,104 glaucomatous and 11,543 normal control eyes were included. Key findings...

European journal of nuclear medicine and molecular imaging, Apr 27, 2017

Prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) is well... more Prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) is well established. There is paucity of data on how the prognostic value of PET relates to the hemodynamic response to vasodilator stress. We hypothesize that inadequate hemodynamic response will affect the prognostic value of PET MPI. Using a multicenter rubidium (Rb)-82 PET registry, 3406 patients who underwent a clinically indicated rest/stress PET MPI with a vasodilator agent were analyzed. Patients were categorized as, "responders" [increase in heart rate ≥ 10 beats per minute (bpm) and decrease in systolic blood pressure (SBP) ≥10 mmHg], "partial responders" (either a change in HR or SBP), and "non-responders" (no change in HR or SBP). Primary outcome was all-cause death (ACD), and secondary outcome was cardiac death (CD). Ischemic burden was measured using summed stress score (SSS) and % left ventricular (LV) ischemia. After a median follow-up of 1.68 years...

Journal of Vascular Surgery

Objectives: The objective of this study is to determine the rate of overall long-term sac regress... more Objectives: The objective of this study is to determine the rate of overall long-term sac regression following endovascular aneurysm repair (EVAR) and the influence of specific endograft devices used at our center. Methods: This retrospective cohort study included all EVARs performed for intact and ruptured abdominal aortic aneurysms (AAAs) at a tertiary care, university teaching hospital. Preoperative, operative, and follow-up data were collected using a regional registry and institutional databases. Preoperative and post-EVAR sac diameters were determined by a blinded observer in accordance with Society for Vascular Surgery guidelines. Absolute and relative sac regression was determined at the intervals of 0 to 6 months, 6 to 12 months, 12 to 18 months, 18 months to 2 years, 2 to 5 years, 5 to 10 years, and >10 years. Results: From 1999 to 2015, 1060 patients underwent EVAR for an AAA at the Ottawa Hospital, using nine unique endograft devices, with five devices (Cook Zenith, n ¼ 398; Medtronic Endurant, n ¼ 375; Medtronic Talent, n ¼ 183; Cook Zenith LP, n ¼ 52; and Terumo Anaconda, n ¼ 23) used in 97% of procedures. The mean preoperative AAA diameter was 61.2 mm, with no detectable differences between endograft devices with respect to age, preoperative AAA diameter, or rupture diagnosis. Overall mean sac regression went from e1.3 mm at 6 months to e14.9 mm >10 years. The majority of sac regression (88.7%) was achieved within 2 years. Only 90 of 1060 patients (8.5%) experienced sac expansion >5 mm at some point during their follow-up period. Kaplan-Meier analysis revealed that Zenith, Zenith LP, and Endurant endografts demonstrated the shortest time to >5 mm sac regression among devices used in >10 patients (Fig 1). In patients who never had a type I endoleak in follow-up, the Zenith 148S Abstracts

Canadian Medical Association Journal

A 27-year-old woman presented to her family doctor with bilateral ocular pain that waxed and wane... more A 27-year-old woman presented to her family doctor with bilateral ocular pain that waxed and waned, redness and photophobia. The symptoms had progressed over several months and were followed by hoarseness and dyspnea, all of which interfered with her activities of daily living. The patient's family doctor referred her simultaneously to an otolaryngologist and a retina specialist. The patient's visual acuity was 20/150 bilaterally. Anterior segment examination showed conjunctival nodules on the inner surface of her lower eyelids (Figure 1), keratic precipitates, inflammatory cells and flare in the anterior chamber, and posterior synechiae (Figure 2). Fundus examination showed papillitis and periphlebitis. These ocular findings were consistent with uveitis. Laboratory workup was negative for infectious causes and showed elevated serum lysozyme, calcium and angiotensinconverting enzyme (ACE) levels. Concurrent investigation of the patient's upper airway symptoms by the oto laryngologist included biopsy of laryngeal nodules, which showed granulomatous inflammation. Multidisciplinary discussion led to a diagnosis of presumed sarcoidosis. Sarcoidosis is a chronic, multisystem, granulomatous disease of unknown cause. 1 Ocular involvement occurs in more than 75% of patients and is the presenting symptom in 20%-30% of cases, most commonly with uveitis and conjunctival nodules, as seen in our patient. 2 Although a slit-lamp examination was required to visualize the patient's fundus findings, anterior signs of uveitis were visible without the aid of magnification. Nonspecific findings included posterior synechiae that resulted from adhesion of the inflamed iris to the lens, which caused an irregular pupil, and keratic precipitates (Figure 2) secondary to deposition of inflammatory leukocytes onto the corneal endothelium, 2 the large "mutton-fat" appearance of which, in our case, suggested granulomatous disease. The differential diagnosis of sarcoidosis is broad, including tuberculosis, Lyme disease and syphilis. Although elevated serum ACE, calcium and lysozyme levels are suggestive of the disease, definitive diagnosis is established by tissue biopsy. 1,2 Goals of treatment are to restore vision and prevent complications of inflammation. Management involves local or systemic corticosteroids, and immunomodulators for severe, chronic disease. 2 Visual prognosis is good in many patients but varies depending on severity and delay in presentation. Given the complex nature of ocular sarcoidosis, early referral to an ophthalmologist and multidisciplinary care are suggested. 2

Journal of Vascular Surgery

Approximately twothirds of the average 30-day cost is attributable to readmission. Older age, fem... more Approximately twothirds of the average 30-day cost is attributable to readmission. Older age, female sex, greater comorbidity level, and longer index admission length of stay were associated with increased 30-day cost. Conclusions: A focus on hospital readmission significantly underestimates 30-day health-related resource use and costs after major vascular surgery.

Endophthalmitis, a potentially devastating inflammatory condition of the vitreous and anterior ch... more Endophthalmitis, a potentially devastating inflammatory condition of the vitreous and anterior chamber, can be either noninfectious or infectious. Infectious endophthalmitis is classified as exogenous or endogenous. Exogenous endophthalmitis occurs secondary to violation of the eye wall as a result of ocular surgery or trauma, with subsequent intraocular microbial inoculation. Endogenous endophthalmitis, which is less frequent, occurs via hematogenous spread of microorganisms to the eye from systemic infection, often in immunocompromised patients. Common infectious foci include meningitis, endocarditis, indwelling catheters, and skin wounds. A 56-year-old male presented with a 2-day history of new floaters in the right eye. Ocular history was significant for surgical repair of a complex rhegmatogenous retinal detachment of the left eye, leading to a blind, painful eye, for which he underwent evisceration 6 weeks prior to developing floaters in his right eye. Systemic review revealed...

Journal of Refractive Surgery Case Reports

International Journal of Keratoconus and Ectatic Corneal Diseases

Aim: Corneal collagen cross-linking (CCL) is a procedure that exposes the cornea to ultraviolet l... more Aim: Corneal collagen cross-linking (CCL) is a procedure that exposes the cornea to ultraviolet light and/or riboflavin to halt the progression of corneal ectatic disease. Currently, most investigations using Fourier-transform infrared spectroscopy (FTIR) of corneal changes following CCL focus on corneal ultrastructure, and not on changes at the molecular level. The aim of this study was to investigate the temporal and spatial separation of corneal collagen linkages that underlie the success of CCL. Materials and methods: Controlled experimental trial. Pairs of donor globes from five patients (n = 10) were divided into interventional and control groups. Interventional group corneas (n = 5) were exposed to riboflavin 0.1% and ultraviolet-A (UVA) light according to the modified Dresden protocol, harvested, cryo-microtomed, and placed on glass slides. Control group corneas (n = 5) underwent cryo-microtoming without CCL. Molecular changes were imaged using the synchrotron mid-infrared beamline at the Canadian Light Source. Results: Fourier-transform infrared spectroscopy imaging of total protein, integrated area under the amide I band from 1,700 to 1,600 cm − 1 , FTIR imaging of collagen triple helix structures, second-derivative intensity as 1,666 cm − 1 , and FTIR imaging of aggregated proteins, secondderivative intensity as 1,625 cm − 1 detected no difference in intramolecular cross-links between the interventional and control corneas. The secondary structure of collagen was neither significantly altered nor was their evidence of aggregation or denaturation within the cornea. Conclusion: Our data suggest that intramolecular cross-linking does not play a major role in CCL and that it is more likely an increase in intermolecular linkages that accounts for increased corneal strength. Clinical significance: An increase in intermolecular linkages likely accounts for the increased corneal strength observed following CCL. We hope that these results will guide future work to optimize techniques for CCL.

Clinical and Investigative Medicine

Purpose: The impact of cardiology fellows (CFs) and interventional cardiology fellows (ICFs) on p... more Purpose: The impact of cardiology fellows (CFs) and interventional cardiology fellows (ICFs) on patient radiation and contrast exposure during diagnostic coronary angiography and percutaneous coronary intervention is unknown. Methods: Between 2011 and 2014, 16,175 cases were retrospectively assessed involving 27 CFs, 22 ICFs and 24 staff as primary operators. Results: During diagnostic coronary angiography, ICFs administered the lowest radiation dose (5,648±5,523 cGy*cm2; 1.30 ± 1.27 mSv)—achieving 22% less radiation than the staff (6,889±4,294 cGy*cm2; 1.58 ± 0.99 mSv) and 36% less than CFs (7,700±6,751 cGy*cm2; 1.77 ± 1.55 mSv) (p<0.01). When adjusted for access site, CFs administered more radiation than either the ICFs or staff. However, differences between ICFs and staff were exclusively observed during transradial procedures (p<0.01). With regards to contrast administration, ICFs administered less contrast (126.3 ± 57.6 mL) than either CFs (130±52.4 mL) or staff (132.7±47...

Clinical Ophthalmology

Background: Glaucoma surgical management has evolved significantly with the introduction of minim... more Background: Glaucoma surgical management has evolved significantly with the introduction of minimally invasive glaucoma surgery. Our aim was to evaluate trends in Canadian glaucoma surgery billing code usage as a surrogate index of the current impact of this new technology in Canada's publicly funded health-care system. Methods: Retrospective administrative health records analysis of all patients who underwent a publicly funded glaucoma filtration procedure from January 2003 to December 2016 in the 6 largest Canadian provinces. The frequency of glaucoma-related procedures was adjusted against primary open-angle glaucoma prevalence data. Frequency of all glaucoma filtration procedures with and without implantation of a drainage device in each province per year is reported. Results: Nationwide, glaucoma filtration procedures per 1000 primary open-angle glaucoma patients per year remained constant, with increased drainage device implantation over time (P<0.0001). Ontario and Nova Scotia mirrored the overall population. British Columbia and Saskatchewan showed increased rates of glaucoma filtration surgery, with increased drainage device implantations. In Quebec, overall filtration surgery decreased, while the rate of device implantation increased (p<0.0001). Alberta showed a decline in filtration surgery and device implantations from 2003 to 2008, and then increased thereafter. Conclusion: Over the study period, there was a distinct trend towards billing code usage for implanted devices. Challenges encountered during this investigation highlight the need for identifiers in provincial health databases to accommodate the introduction of novel technologies. The absence of specific billing codes for newer technologies prevents accurate analyses of impact, utilization, efficacy and cost implications in contemporary patient management.

Seminars in Ophthalmology

Journal of Vascular Surgery

Canadian Journal of Ophthalmology

Clinical Ophthalmology

Purpose: To develop and validate neural network (NN) vs logistic regression (LR) diagnostic predi... more Purpose: To develop and validate neural network (NN) vs logistic regression (LR) diagnostic prediction models in patients with suspected giant cell arteritis (GCA). Design: Multicenter retrospective chart review. Methods: An audit of consecutive patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at 14 international medical centers. The outcome variable was biopsy-proven GCA. The predictor variables were age, gender, headache, clinical temporal artery abnormality, jaw claudication, vision loss, diplopia, erythrocyte sedimentation rate, C-reactive protein, and platelet level. The data were divided into three groups to train, validate, and test the models. The NN model with the lowest false-negative rate was chosen. Internal and external validations were performed. Results: Of 1,833 patients who underwent TABx, there was complete information on 1,201 patients, 300 (25%) of whom had a positive TABx. On multivariable LR age, platelets, jaw claudication, vision loss, log C-reactive protein, log erythrocyte sedimentation rate, headache, and clinical temporal artery abnormality were statistically significant predictors of a positive TABx (P#0.05). The area under the receiver operating characteristic curve/Hosmer-Lemeshow P for LR was 0.867 (95% CI, 0.794, 0.917)/0.119 vs NN 0.860 (95% CI, 0.786, 0.911)/0.805, with no statistically significant difference of the area under the curves (P=0.316). The misclassification rate/false-negative rate of LR was 20.6%/47.5% vs 18.1%/30.5% for NN. Missing data analysis did not change the results. Conclusion: Statistical models can aid in the triage of patients with suspected GCA. Misclassification remains a concern, but cutoff values for 95% and 99% sensitivities are provided (https://goo.gl/THCnuU).

European Journal of Vascular and Endovascular Surgery

WHAT THIS PAPER ADDS Late open surgical conversion following endovascular aneurysm repair is asso... more WHAT THIS PAPER ADDS Late open surgical conversion following endovascular aneurysm repair is associated with significant morbidity and mortality. Although endograft preservation may be preferentially offered as a less invasive alternative to high risk patients requiring open surgical conversion, significant mortality was identified with this procedure. Adherence to device instructions for use (IFU) is markedly lower among EVARs requiring open surgical conversion than uncomplicated cases. There was a trend for decreasing interval to conversion; an association with liberalisation of EVAR outside of IFU is possible, but cannot be concluded from this study. Introduction: Late open surgical conversion following endovascular aneurysm repair (EVAR) may occur more frequently after performing EVAR in anatomy outside the instructions for use (IFU). This study reviews predictors and outcomes of late open surgical conversion for failed EVAR. Methods: This retrospective cohort study reviewed all EVARs performed at the Ottawa Hospital between January 1999 and May 2015. Open surgical conversions >1 month post EVAR were identified. Variables analysed included indication for conversion, pre-intervention AAA anatomy, endovascular device and configuration, operative technique, re-interventions, complications, and death. Results: Of 1060 consecutive EVARs performed, 16 required late open surgical conversion. Endografts implanted were Medtronic Talent (n ¼ 8, 50.0%), Medtronic Endurant (n ¼ 3, 18.8%), Cook Zenith (n ¼ 4, 25.0%), and Terumo Anaconda (n ¼ 1, 6.2%). Eleven grafts were bifurcated (68.8%), five were aorto-uni-iliac (31.2%). The median time to open surgical conversion was 3.1 (IQR 1.0e5.2) years. There was no significant difference in pre-EVAR rupture status (1.4% elective, 2.1% ruptured, p ¼ .54). Indications for conversion included: Type 1 endoleak with sac expansion (n ¼ 4, 25.0%), Type 2 endoleak with expansion (n ¼ 2, 12.5%), migration (n ¼ 3, 18.8%), sac expansion without endoleak (n ¼ 2, 12.5%), graft infection (n ¼ 3, 18.8%), rupture (n ¼ 2, 12.5%). Nine patients (56.2%) underwent stent graft explantation with in situ surgical graft reconstruction, seven had endograft preserving open surgical intervention. The 30 day mortality was 18.8% (n ¼ 3, all of whom having had endograft preservation). Ten patients (62.5%) suffered major in hospital complications. One patient (6.5%) required postconversion major surgical re-intervention. IFU adherence during initial EVAR was 43.8%, versus 79.0% (p < .01) among uncomplicated EVARs. Conclusions: Open surgical conversion following EVAR results in significant morbidity and mortality. IFU adherence of EVARs later requiring open surgical conversion is markedly low. More data are required to elucidate the impact of increasing liberalisation of EVAR outside of IFU.

Ophthalmology, Jan 16, 2018

To determine whether differences between eyes in axial length (AL) and corneal power (K) on optic... more To determine whether differences between eyes in axial length (AL) and corneal power (K) on optical biometry are predictive of refractive outcomes. Retrospective cohort study. A total of 729 patients (1458 eyes) who underwent bilateral phacoemulsification at TLC (Mississauga, Ontario, Canada) from September 2013 to August 2015. We compared the proportion of patients having >0.5 diopters (D) of refractive error from target stratified by interocular axial length differences (IALDs) and interocular K differences (IKDs) between eyes as measured by optical biometry (IOL-Master, Carl Zeiss Meditec, Oberkochen, Germany). Analysis was repeated for 0.25 D or 1.0 D targets and for patients with uncorrected visual acuity (UCVA) >0.3 logarithm of the minimum angle of resolution (logMAR) postoperatively. Proportions, odds ratios (ORs), and corresponding 95% confidence intervals (CIs) were computed using generalized estimating equations to account for within-patient correlation. Some 79.1% ...

Canadian journal of ophthalmology. Journal canadien d'ophtalmologie, 2018

Temporal artery biopsy (TAB) is the gold standard for confirming the diagnosis of giant cell arte... more Temporal artery biopsy (TAB) is the gold standard for confirming the diagnosis of giant cell arteritis (GCA) when positive. However, the clinical significance of healed/healing (HH) arterial injury on TAB is not well understood. The purpose of this study was to evaluate the clinical significance of this finding on TAB by determining its association with seromarkers typically predictive of GCA. Single-centre, retrospective, investigational cohort study. A total of 385 consecutive TABs for clinical suspicion of GCA between January 2009 and January 2016. Elevations in erythrocyte sedimentation rate, C-reactive protein, and platelet count were compared between patients with negative TAB, GCA-positive TAB, and HH arterial injury using statistical trend testing. Odds ratios of seromarker elevations for HH arterial injury versus GCA were calculated. Seventy-six GCA-positive, 69 HH, and 240 negative TABs were identified. Mantel-Haenszel tests of trend indicated that platelets >400 000/µL...

PloS one, 2018

Early detection, monitoring and understanding of changes in the retina are central to the diagnos... more Early detection, monitoring and understanding of changes in the retina are central to the diagnosis of glaucomatous optic neuropathy, and vital to reduce visual loss from this progressive condition. The main objective of this investigation was to compare glaucoma diagnostic accuracy of commercially available optical coherence tomography (OCT) devices (Zeiss Stratus, Zeiss Cirrus, Heidelberg Spectralis and Optovue RTVue, and Topcon 3D-OCT). 16,104 glaucomatous and 11,543 normal eyes reported in 150 studies. Between Jan. 2017 and Feb 2017, MEDLINE®, EMBASE®, CINAHL®, Cochrane Library®, Web of Science®, and BIOSIS® were searched for studies assessing glaucoma diagnostic accuracy of the aforementioned OCT devices. Meta-analysis was performed pooling area under the receiver operating characteristic curve (AUROC) estimates for all devices, stratified by OCT type (RNFL, macula), and area imaged. 150 studies with 16,104 glaucomatous and 11,543 normal control eyes were included. Key findings...

European journal of nuclear medicine and molecular imaging, Apr 27, 2017

Prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) is well... more Prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) is well established. There is paucity of data on how the prognostic value of PET relates to the hemodynamic response to vasodilator stress. We hypothesize that inadequate hemodynamic response will affect the prognostic value of PET MPI. Using a multicenter rubidium (Rb)-82 PET registry, 3406 patients who underwent a clinically indicated rest/stress PET MPI with a vasodilator agent were analyzed. Patients were categorized as, "responders" [increase in heart rate ≥ 10 beats per minute (bpm) and decrease in systolic blood pressure (SBP) ≥10 mmHg], "partial responders" (either a change in HR or SBP), and "non-responders" (no change in HR or SBP). Primary outcome was all-cause death (ACD), and secondary outcome was cardiac death (CD). Ischemic burden was measured using summed stress score (SSS) and % left ventricular (LV) ischemia. After a median follow-up of 1.68 years...

Journal of Vascular Surgery

Objectives: The objective of this study is to determine the rate of overall long-term sac regress... more Objectives: The objective of this study is to determine the rate of overall long-term sac regression following endovascular aneurysm repair (EVAR) and the influence of specific endograft devices used at our center. Methods: This retrospective cohort study included all EVARs performed for intact and ruptured abdominal aortic aneurysms (AAAs) at a tertiary care, university teaching hospital. Preoperative, operative, and follow-up data were collected using a regional registry and institutional databases. Preoperative and post-EVAR sac diameters were determined by a blinded observer in accordance with Society for Vascular Surgery guidelines. Absolute and relative sac regression was determined at the intervals of 0 to 6 months, 6 to 12 months, 12 to 18 months, 18 months to 2 years, 2 to 5 years, 5 to 10 years, and >10 years. Results: From 1999 to 2015, 1060 patients underwent EVAR for an AAA at the Ottawa Hospital, using nine unique endograft devices, with five devices (Cook Zenith, n ¼ 398; Medtronic Endurant, n ¼ 375; Medtronic Talent, n ¼ 183; Cook Zenith LP, n ¼ 52; and Terumo Anaconda, n ¼ 23) used in 97% of procedures. The mean preoperative AAA diameter was 61.2 mm, with no detectable differences between endograft devices with respect to age, preoperative AAA diameter, or rupture diagnosis. Overall mean sac regression went from e1.3 mm at 6 months to e14.9 mm >10 years. The majority of sac regression (88.7%) was achieved within 2 years. Only 90 of 1060 patients (8.5%) experienced sac expansion >5 mm at some point during their follow-up period. Kaplan-Meier analysis revealed that Zenith, Zenith LP, and Endurant endografts demonstrated the shortest time to >5 mm sac regression among devices used in >10 patients (Fig 1). In patients who never had a type I endoleak in follow-up, the Zenith 148S Abstracts

Canadian Medical Association Journal

A 27-year-old woman presented to her family doctor with bilateral ocular pain that waxed and wane... more A 27-year-old woman presented to her family doctor with bilateral ocular pain that waxed and waned, redness and photophobia. The symptoms had progressed over several months and were followed by hoarseness and dyspnea, all of which interfered with her activities of daily living. The patient's family doctor referred her simultaneously to an otolaryngologist and a retina specialist. The patient's visual acuity was 20/150 bilaterally. Anterior segment examination showed conjunctival nodules on the inner surface of her lower eyelids (Figure 1), keratic precipitates, inflammatory cells and flare in the anterior chamber, and posterior synechiae (Figure 2). Fundus examination showed papillitis and periphlebitis. These ocular findings were consistent with uveitis. Laboratory workup was negative for infectious causes and showed elevated serum lysozyme, calcium and angiotensinconverting enzyme (ACE) levels. Concurrent investigation of the patient's upper airway symptoms by the oto laryngologist included biopsy of laryngeal nodules, which showed granulomatous inflammation. Multidisciplinary discussion led to a diagnosis of presumed sarcoidosis. Sarcoidosis is a chronic, multisystem, granulomatous disease of unknown cause. 1 Ocular involvement occurs in more than 75% of patients and is the presenting symptom in 20%-30% of cases, most commonly with uveitis and conjunctival nodules, as seen in our patient. 2 Although a slit-lamp examination was required to visualize the patient's fundus findings, anterior signs of uveitis were visible without the aid of magnification. Nonspecific findings included posterior synechiae that resulted from adhesion of the inflamed iris to the lens, which caused an irregular pupil, and keratic precipitates (Figure 2) secondary to deposition of inflammatory leukocytes onto the corneal endothelium, 2 the large "mutton-fat" appearance of which, in our case, suggested granulomatous disease. The differential diagnosis of sarcoidosis is broad, including tuberculosis, Lyme disease and syphilis. Although elevated serum ACE, calcium and lysozyme levels are suggestive of the disease, definitive diagnosis is established by tissue biopsy. 1,2 Goals of treatment are to restore vision and prevent complications of inflammation. Management involves local or systemic corticosteroids, and immunomodulators for severe, chronic disease. 2 Visual prognosis is good in many patients but varies depending on severity and delay in presentation. Given the complex nature of ocular sarcoidosis, early referral to an ophthalmologist and multidisciplinary care are suggested. 2

Journal of Vascular Surgery

Approximately twothirds of the average 30-day cost is attributable to readmission. Older age, fem... more Approximately twothirds of the average 30-day cost is attributable to readmission. Older age, female sex, greater comorbidity level, and longer index admission length of stay were associated with increased 30-day cost. Conclusions: A focus on hospital readmission significantly underestimates 30-day health-related resource use and costs after major vascular surgery.