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Dive into the research topics where Michael Chetner is active.

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Featured researches published by Michael Chetner.


The Journal of Urology | 2008

Associations Among Age, Comorbidity and Clinical Outcomes After Radical Cystectomy: Results From the Alberta Urology Institute Radical Cystectomy Database

Adrian Fairey; Michael Chetner; James B. Metcalfe; Ronald B. Moore; Gerald Todd; Keith Rourke; Don Voaklander; Eric Estey

PURPOSE We determined the associations among age, comorbidity and clinical outcomes after radical cystectomy. MATERIALS AND METHODS The study was a retrospective cohort analysis of 314 consecutive patients with primary bladder cancer treated with radical cystectomy between January 2000 and December 2006 in Edmonton, Canada. Comorbidity was obtained through a medical record review using the Adult Comorbidity Evaluation-27 instrument. The main clinical outcomes were 90-day mortality, early postoperative complications, and major and minor early postoperative complications. Logistic regression analyses were used to determine predictors of clinical outcomes. RESULTS The 90-day mortality, any early postoperative complications, and major and minor early postoperative complications occurred in 18 (5.7%), 148 (47.1%), 78 (24.8%) and 92 (29.3%) patients, respectively. In univariate and multivariate logistic regression analysis age was not associated with 90-day mortality or early postoperative complications. In contrast, compared to patients with no or mild comorbidity, multivariate logistic regression analysis adjusted for age and surgeon procedure volume showed that severe comorbidity was associated with an increased risk of 90-day mortality (OR 6.4, p = 0.03). In addition, compared to patients with no or mild comorbidity, multivariate logistic regression analysis adjusted for age, sex, surgeon procedure volume, type of urinary tract reconstruction and American Joint Committee on Cancer stage showed that moderate and severe comorbidity were associated with any early postoperative complications (moderate OR 5.2, p <0.001; severe OR 7.0, p <0.001), major early postoperative complications (moderate OR 11.4, p <0.001; severe OR 15.2, p <0.001) and minor early postoperative complications (moderate OR 2.1, p = 0.019; severe OR 2.2, p = 0.038). CONCLUSIONS Increasing comorbidity was independently associated with an increased risk of 90-day mortality and early postoperative complications after radical cystectomy.


Urology | 2008

Return to Continence After Radical Retropubic Prostatectomy: A Randomized Trial of Verbal and Written Instructions Versus Therapist-Directed Pelvic Floor Muscle Therapy

Katherine N. Moore; Luc Valiquette; Michael Chetner; Stephen Byrniak; G. Peter Herbison

OBJECTIVES To test the effectiveness of weekly postoperative pelvic floor muscle training (PFMT) versus supportive telephone contact by a urology nurse for men at 4 weeks after radical prostatectomy. METHODS This was a randomized controlled trial in three Canadian centers. At 4 weeks after surgery, standardized verbal and written instruction about PFMT was provided to all subjects. Randomization occurred after initial instruction. Continence was defined as 8 g or less of urine loss on a 24-hour pad test. Primary outcome was grams of urine loss on pad test; secondary outcomes were International Prostate Symptom Score (IPSS), Incontinence Impact Questionnaire (IIQ-7) score, cost, and perception of urine loss as a problem. Data were obtained at baseline (preoperatively) and at weeks 4, 8, 12, 16, and 28 and 1 year after surgery. RESULTS A total of 216 men were enrolled; 11 were dry or withdrew at 4 weeks. Ninety-nine were randomized to the control group and 106 to the treatment group. There were no group differences at baseline for prostate-specific antigen level (mean [standard deviation] 8.4 [10.4] ng/mL; 7.6 [4.6] ng/mL), Gleason score (6.3 [0.86]), IPSS, IIQ-7 score, pad test, or voiding diary. At 8 weeks 23% of the control group and 20% of the treatment group were continent; at 12 weeks, 28% and 32%; 16 weeks, 40% and 44%; 28 weeks, 50% and 47%; and at 52 weeks, 64% and 60%, respectively. There were no significant differences between groups at any time point for the outcome variables. CONCLUSIONS Verbal instruction and written information with telephone support seemed to be as effective as intensive PFMT. Less-intense therapy may be more cost-effective.


Urology | 1992

Lower urinary tract dysfunction in multiple sclerosis

Michael E. Mayo; Michael Chetner

Previous investigators have shown that in multiple sclerosis failure to empty the bladder was secondary to detrusor-distal sphincter dyssynergia or areflexia. However, our urodynamic evaluation of 46 female and 43 male patients with multiple sclerosis revealed that 63 percent of patients failed to empty their bladders because of a hypocontractile detrusor, and only 6 percent had areflexia. Detrusor-distal sphincter dyssynergia (6%) and bladder neck obstruction (6%) were present in only 12 percent of patients. Hyperreflexia was common (78%) and was associated with hypocontractility in 63 percent of patients. Urgency incontinence was significantly more common in females and voiding difficulty significantly more common in males. Sensation was also reduced in 74 percent of female and 77 percent of male patients. In conclusion, failure to empty the bladder in multiple sclerosis is most commonly associated with hypocontractility, and the combination of hyperreflexia and hypocontractility produces the symptoms of urgency and incomplete emptying.


The Journal of Urology | 1999

LONG-TERM FOLLOWUP OF THE NORTH AMERICAN MULTICENTER UROLUME* TRIAL FOR THE TREATMENT OF EXTERNAL DETRUSOR-SPHINCTER DYSSYNERGIA

Michael B. Chancellor; Jerzy B. Gajewski; C. F Douglas Ackman; Rodney A. Appell; James Bennett; Joseph Binard; Timothy B. Boone; Michael Chetner; Julie Ann Crewalk; Alfred J. Defalco; Jenelle Foote; Bruce G. Green; Saad Juma; Suk Young Jung; Todd A. Linsenmeyer; Robert MacMillan; Michael E. Mayo; Hideo Ozawa; Claus G. Roehrborn; Patrick J. Shenot; Anthony R. Stone; Albert Vazquez; Wylly Killorin; David A. Rivas

PURPOSE We determine the long-term efficacy and safety of the UroLume stent as minimally invasive treatment for external detrusor-sphincter dyssynergia in spinal cord injured men. MATERIALS AND METHODS A total of 160 spinal cord injured men with a mean age plus or minus standard deviation of 36.3 +/- 12.1 years (range 16 to 74) were prospectively treated with an endoprosthesis at 15 centers as part of the North American UroLume trial for external detrusor-sphincter dyssynergia. Urodynamic parameters, including voiding pressure, residual urine volume and bladder capacity, were compared before treatment and at 1, 2, 3, 4 and 5 years after treatment. RESULTS Mean voiding pressure was 75.1 +/- 28.2 cm. water before treatment in the 160 patients, and 37.4 +/- 23.9 at year 1 in 97, 39.5 +/- 22.2 at year 2 in 84, 42.6 +/- 27.3 at year 3 in 61, 46.3 +/- 33.2 at year 4 in 57 and 44.2 +/- 28.9 cm. at year 5 in 41 after stent insertion (p <0.001). Residual urine volume decreased after stent placement and was maintained throughout the 5-year followup (p <0.001). Mean cystometric capacity remained constant from 269 +/- 155 before insertion to 337 +/- 182 ml. 5 years later (p = 0.17). Hydronephrosis and autonomic dysreflexia improved or stabilized in most patients with functioning stents. Stent explant was necessary in 24 patients (15%), of whom 4 (16.7%) had another stent implanted. CONCLUSIONS The UroLume stent demonstrates long-term safety and efficacy for the treatment of external detrusor-sphincter dyssynergia. The outcome was similar in men with and without previous sphincterotomy.


International Journal of Radiation Oncology Biology Physics | 2001

Muscle-invasive transitional cell carcinoma of the urinary bladder : A population-based study of patterns of care and prognostic factors

Rufus Scrimger; Albert Murtha; Matthew Parliament; Peter Venner; John Hanson; Greg Houle; Michael Chetner

PURPOSE Population-based cancer registries can permit the study of the survivorship of all patients with a particular diagnosis regardless of patterns of referral and practice within a specific geographic distribution. The purpose of this study is to describe the patterns of care, outcome, and prognostic factors for bladder cancer in the northern region of the province of Alberta, Canada, between 1984 and 1993. METHODS AND MATERIALS Between 1984 and 1993, 184 patients from northern Alberta were identified from the Alberta Cancer Registry as having undergone curative treatment for biopsy-proven muscle-invasive transitional cell carcinoma of the bladder. Data were obtained, by retrospective chart review, regarding the staging, pathology, treatment, and outcome of patients treated in the northern Alberta cities of Edmonton, Grande Prairie, and Red Deer, regardless of the responsible treating institution. The prognostic significance of patient-, tumor-, and treatment-related variables were tested using univariate and multivariate analysis using the Cox proportional-hazard model. RESULTS As the primary treatment modality, 74 patients (40%) received radical radiotherapy (RT) without surgery; surgery was used alone in 81 patients (44%), and was combined with preoperative or postoperative radiotherapy in 29 patients (16%). Seventy-three (40%) patients also received concurrent, neoadjuvant, or adjuvant chemotherapy. The Kaplan-Meier estimate of median survival was 2.2 years, and the 5-year overall survival was 30%. Univariate analysis demonstrated the prognostic significance of T classification (p < 0.001), lymph node involvement (p < 0.001), complete response to RT (p = 0.001), hydronephrosis (p = 0.017), and vascular/lymphatic involvement (p = 0.035). Multivariate analysis revealed the following to have a significant association with survival: T classification (p = 0.001), lymph node involvement (p = 0.004), complete response to RT (p = 0.054), hydronephrosis (p = 0.019), and use of chemotherapy in the treatment regimen (p = 0.025). CONCLUSION The strongest prognostic factors in this study were tumor related, and no significant differences in survival were detected between patients treated with primary surgery vs. organ-preservation approaches. A survival advantage associated with the incorporation of chemotherapy into the management schema was detected on multivariate, but not univariate, analysis. Stratification of patients based on tumor characteristics is imperative in clinical trials for invasive bladder cancer. Novel treatment approaches are required to improve survival further in patients with apparently localized disease.


The Journal of Urology | 2009

Associations Between Comorbidity, and Overall Survival and Bladder Cancer Specific Survival After Radical Cystectomy: Results From the Alberta Urology Institute Radical Cystectomy Database

Adrian Fairey; Niels-Erik Jacobsen; Michael Chetner; David R. Mador; James B. Metcalfe; Ronald B. Moore; Keith Rourke; Gerald Todd; Peter Venner; Don Voaklander; Eric Estey

PURPOSE We determined the associations between comorbidity, and overall survival and bladder cancer specific survival after radical cystectomy. MATERIALS AND METHODS The Alberta Urology Institute Radical Cystectomy database is an ongoing multi-institutional computerized database containing data on all adult patients with a diagnosis of primary bladder cancer treated with radical cystectomy in Edmonton, Canada from April 1994 forward. The current study is an analysis of consecutive database patients treated between April 1994 and September 2007. Comorbidity information was obtained through a medical record review using the Adult Comorbidity Evaluation 27 instrument. The outcome measures were overall survival and bladder cancer specific survival. Cox proportional regression analysis was used to determine the associations between comorbidity, and overall survival and bladder cancer specific survival. RESULTS Of the database patients 160 (34%), 225 (48%) and 83 (18%) had no/mild comorbidity, moderate comorbidity and severe comorbidity, respectively. Compared to patients with no or mild comorbidity, multivariate Cox proportional regression analyses that included age, adjuvant chemotherapy, surgeon procedure volume, pathological T stage, pathological lymph node status, total number of lymph nodes removed, surgical margin status and lymphovascular invasion showed that increased comorbidity was independently associated with overall survival (moderate HR 1.59, 95% CI 1.16-2.18, p = 0.004; severe HR 1.83, 95% CI 1.22-2.72, p = 0.003) and bladder cancer specific survival (moderate HR 1.50, 95% CI 1.04-2.15, p = 0.028; severe HR 1.65, 95% CI 1.04-2.62, p = 0.034). CONCLUSIONS Increased comorbidity was independently associated with an increased risk of overall mortality and bladder cancer specific mortality after radical cystectomy.


The Journal of Urology | 1994

Multicenter trial in North America of UroLume urinary sphincter prosthesis.

Michael B. Chancellor; David A. Rivas; Todd A. Linsenmeyer; Caryn A. Abdill; C. F Douglas Ackman; Rodney A. Appell; James Bennett; Joseph Binard; Timothy B. Boone; Michael Chetner; Alfred Defalco; Janelle Foote; Jerzy B. Gajewski; Bruce G. Green; Saad Juma; Robert MacMillan; Michael E. Mayo; Claus G. Roehrborn; Anthony R. Stone; W.C. Thorndyke; Albert Vazquez

We investigated the effectiveness and associated complications of treatment with an endoluminal urethral sphincter prosthesis in 153 spinal cord injury men (mean age 36 years, range 16 to 74 years) with urodynamically diagnosed detrusor-external sphincter dyssynergia. These patients were prospectively treated with a urethral sphincter stent at 15 centers in North America. Followup ranged from 2 to 33 months. Voiding pressures averaged 76 +/- 28, 42 +/- 21, 44 +/- 38, 35 +/- 18 and 32 +/- 20 cm. water, respectively, before prosthesis insertion in 153 patients and at 3 months in 123, 6 months in 114, 12 months in 98 and 24 months in 22. A significant decrease in voiding pressure was noted in the 22 patients at 24 months compared with matched preoperative data (80 +/- 25 cm. water, p = 0.03). The residual urine decreased from 181 +/- 154 ml. before insertion to 82 +/- 93 ml. at 24 months (p = 0.01). Maximum cystometric capacity remained constant, with a mean of 195 +/- 158 ml. before insertion to 248 +/- 122 ml. at 24 months (p = 0.17). No significant differences were apparent after 24 months of followup in any of the urodynamic parameters between 44 patients with and 109 without previous external sphincterotomy. Hemorrhage requiring blood transfusion, obstructive hyperplastic epithelial overgrowth and soft tissue erosion did not occur. No deleterious effects were observed on renal or erectile function. Of the patients 43 (28.1%) required 2 prostheses to bridge the external sphincter completely. Stent removal was required in 10 patients. Seven explantations were required for prosthesis migration, 1 for pain and urethral edema, 1 for inability to maintain a condom catheter, and 1 for nonepithelialization and secondary bladder neck obstruction. A total of 13 patients (8.5%) required a subsequent operation for bladder neck obstruction. Therefore, the sphincter prosthesis is an attractive modality for the treatment of external sphincter dyssynergia in patients with and without previous external sphincterotomy because of its ease of deployment and minimal associated morbidity.


Cuaj-canadian Urological Association Journal | 2011

Prostate cancer screening: Canadian guidelines 2011

Jonathan I. Izawa; Laurence Klotz; D. Robert Siemens; Wassim Kassouf; Alan So; John Jordan; Michael Chetner; Alla E. Iansavichene

The goal of prostate cancer (PCa) screening is to reduce the morbidity and mortality from this disease through early detection. There has been a steady decline in PCa mortality following the introduction of PSA testing in the late 1980s.1 However, phase III trials on PCa screening have demonstrated a high number needed to treat, suggesting many PCas diagnosed were not destined to have an impact on a patient’s overall survival.2,3 (Level 1 Evidence.) We review the literature on PCa screening and describe what contemporary screening entails. We offer guidelines to facilitate the discussion of the risks and benefits of PCa screening. These guidelines are recommendations; they are not a standard of care for all patients and should not pre-empt a physician’s clinical judgment.


The Journal of Urology | 2000

REMOVAL OF UROLUME ENDOPROSTHESIS: EXPERIENCE OF THE NORTH AMERICAN STUDY GROUP FOR DETRUSOR-SPHINCTER DYSSYNERGIA APPLICATION

Jerzy B. Gajewski; Michael B. Chancellor; C. F Douglas Ackman; Rodney A. Appell; James Bennett; Joseph Binard; Timothy B. Boone; Michael Chetner; Julie Ann Crewalk; Alfredo Defalco; Jenelle Foote; Bruce G. Green; Saad Juma; Suk Young Jung; Todd A. Linsenmeyer; Joseph N. Macaluso; Robert MacMillan; Michael E. Mayo; Hideo Ozawa; Claus G. Roehrborn; Joseph D. Schmidt; Patrick J. Shenot; Anthony R. Stone; Albert Vazquez; Wylly Killorin; David A. Rivas

PURPOSE We present the experience of the North American UroLume Multicenter Study Group with removal of the UroLume endoprosthesis. MATERIALS AND METHODS A total of 160 neurologically impaired patients were enrolled in the North American UroLume Multicenter Study Group for detrusor external sphincter dyssynergia application. Analysis was performed in 2 groups of patients in which the device was removed during insertion and after implantation, respectively. RESULTS Device retrieval was required during insertion in 21 patients (13%) mainly due to misplacement or migration in 17. Extraction was done with minimal complications and in all but 2 cases subsequent UroLume implantation was successful. Of 158 men with the device in place 31 (19.6%) required removal. In 34 procedures 44 devices were removed, mainly due to migration. Time from implantation to removal ranged from 4 days to 66 months (mean 22 months). The UroLume was removed en bloc in 20 cases and in parts or wire by wire in 19. The majority of patients had no or minimal complications after extraction. Only 2 patients had serious temporary complications, including bleeding and urethral injury, with no lasting consequences. No malignancy developed as a result of UroLume insertion. CONCLUSIONS While there is a potential for urethral injury and bleeding, UroLume endoprosthesis removal is largely a simple procedure with minimal complications and consequences.


Cuaj-canadian Urological Association Journal | 2011

Furthering the prostate cancer screening debate (prostate cancer specific mortality and associated risks)

G. Michael Allan; Michael Chetner; Bryan J. Donnelly; Neil A. Hagen; David B. Ross; J. Dean Ruether; Peter Venner

Screening for prostate cancer remains a contentious issue. As with other cancer screening programs, a key feature of the debate is verification of cancer-specific mortality reductions. Unfortunately the present evidence, two systematic reviews and six randomized controlled trials, have reported conflicting results. Furthermore, half of the studies are poor quality and the evidence is clouded by key weaknesses, including poor adherence to screening in the intervention arm or high rates of screening in the control arm. In high quality studies of prostate cancer screening (particularly prostate-specific antigen), in which actual compliance was anticipated in the study design, there is good evidence that prostate cancer mortality is reduced. The numbers needed to screen are at least as good as those of mammography for breast cancer and fecal occult blood testing for colorectal cancer. However, the risks associated with prostate cancer screening are considerable and must be weighed against the advantage of reduced cancer-specific mortality. Adverse events include 70% rate of false positives, important risks associated with prostate biopsy, and the serious consequences of prostate cancer treatment. The best evidence demonstrates prostate cancer screening will reduce prostate cancer mortality. It is time for the debate to move beyond this issue, and begin a well-informed discussion on the remaining complex issues associated with prostate cancer screening and appropriate management.

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Alan So

University of British Columbia

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Bruce G. Green

University of Southern California

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