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Dive into the research topics where Serge Simard is active.

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Featured researches published by Serge Simard.


World Journal of Surgery | 1998

Biliopancreatic Diversion with Duodenal Switch

Picard Marceau; Frédéric-Simon Hould; Serge Simard; Stéphane Lebel; Roch-André Bourque; Martin Potvin; Simon Biron

Abstract. In 1990 Scopinaro’s technique of biliopancreatic diversion with distal gastrectomy (DG) and gastroileostomy was modified. A sleeve gastrectomy with duodenal switch (DS) was used instead of the distal gastrectomy; and the length of the common channel was made 100 cm instead of 50 cm. A questionnaire and a prescription for blood work were sent to 252 patients who underwent DG a mean 8.3 years ago (range 6–13 years) and 465 patients who underwent DS 4.1 years ago (range 1.7–6.0 years). The questionnaire response rate was 93%, and laboratory work was completed for 65% of both groups. The mean weight loss after DG was 37 ± 21 kg and after DS 46 ± 20 kg. There were fewer side effects after DS: The number of daily stools was lower (p < 0.0002), as was the prevalence of diarrhea (p < 0.01), vomiting (p < 0.001), and bone pain (p < 0.001). Greater benefits related to several aspects of life were reported after DS than DG (p < 0.0001). The mean serum levels of ferritin, calcium, and vitamin A were higher (p < 0.001), and parathyroid hormone was lower. The yearly revision rate for excessive malabsorption was 1.7% per year after DG and 0.1% per year after DS. The two procedures were equally efficient for treating co-morbid conditions such as diabetes, hypertension, and hypercholesterolemia. Biliopancreatic diversion with sleeve gastrectomy/duodenal switch and a 100-cm common limb was shown to produce greater weight loss with fewer side effects.


Circulation | 2003

Impact of Valve Prosthesis-Patient Mismatch on Short-Term Mortality After Aortic Valve Replacement

Claudia Blais; Jean G. Dumesnil; Richard Baillot; Serge Simard; Daniel Doyle; Philippe Pibarot

Background—The prosthesis used for aortic valve replacement (AVR) can be too small in relation to body size, thus causing valve prosthesis-patient mismatch (PPM) and abnormally high transvalvular pressure gradients. This study examined if there is a relation between PPM and short-term mortality after operation. Methods and Results—The indexed valve effective orifice area (EOA) was estimated for each type and size of prosthesis being implanted in 1266 consecutive patients and used to define PPM as not clinically significant if >0.85 cm2/m2, as moderate if >0.65 cm2/m2 and ≤0.85 cm2/m2, and as severe if ≤0.65 cm2/m2; it was correlated with 30-day mortality and compared with other relevant variables. Moderate or severe PPM was present in 38% of patients. Thirty-day mortality was 4.6% (58/1266 patients) and the strongest independent predictors in multivariate analysis were left ventricular ejection fraction <40% (P =0.007), infectious endocarditis (P =0.002), emergent/salvage operation (P =0.002), cardiopulmonary bypass time >120 minutes (P =0.001), and PPM (P =0.003). Relative risk of mortality was increased 2.1-fold (95% confidence interval, 1.2 to 3.7) in patients with moderate PPM and 11.4-fold (4.4 to 29.5) in those with severe PPM. Moreover, risk of mortality for every category of PPM was higher in patients with a left ventricular ejection fraction <40% as compared with ≥40% (nonsignificant PPM, 2.7 versus 1.0; moderate PPM, 7.1 versus 1.8; severe PPM, 77.1 versus 11.3). Conclusion—PPM is a strong and independent predictor of short-term mortality among patients undergoing AVR, and its impact is related both to its degree of severity and the status of left ventricular function. In contrast to other risk factors, moderate-severe PPM can be largely avoided with the use of a prospective strategy at the time of operation.


Obesity Surgery | 1993

Biliopancreatic Diversion with a New Type of Gastrectomy

Picard Marceau; Simon Biron; Roch-André Bourque; Martin Potvin; Frédéric-Simon Hould; Serge Simard

In an attempt to improve the results of biliopancreatic diversion in the treatment of morbid obesity, two aspects of the procedure performed at Laval Hospital were modified to reduce adverse physiological consequences. The distal gastrectomy was replaced by a parietal gastrectomy which preserves vagal continuity along with the lesser curvature, and leaves intact the antro-pyloro-duodenal pump. The duodenum was stapled shut and nutrients were diverted through a duodeno-ileal anastomosis. The biliopancreatic diverting intestinal limb was anastomosed to the nutrient ileal limb 100 cm proximal to the ileocaecal valve instead of 50 cm proximal to it, thus doubling the length of the common ileal absorptive segment. Weight loss after either operation was greater than 70% of initial excess weight. Following the new operation, there was a lesser prevalence of side-effects, especially loose stools and malodorous gas, a lesser degree of hypocalcemia and no hypoalbuminemia. The duodenum recanalized at the staple line in 20% of the patients who had the new operation. When data from these patients were excluded, weight loss following the new operation was greater than that seen after the old one. The prevalence of side-effects and the degree of calcium and protein malabsorption remained significantly lower. Weight loss remained satisfactory with a common limb measuring 100 cm. The parietal gastrectomy was not restrictive as shown by the failure to lose further weight when the duodenal stapled diversion failed. Weight loss was thus mainly a function of biliopancreatic diversion, but increased weight loss in the new procedure despite a doubling of the common ileal limb suggests that parietal gastrectomy contributed to weight loss. Because duodenal recanalization can be corrected surgically and now prevented, the modified biliopancreatic bypass is preferred.


Pediatrics | 2006

Large maternal weight loss from obesity surgery prevents transmission of obesity to children who were followed for 2 to 18 years.

John G. Kral; Simon Biron; Serge Simard; Frédéric-Simon Hould; Stéfane Lebel; Simon Marceau; Picard Marceau

OBJECTIVE. Our aim was to compare the prevalence of obesity in 172 children who were aged 2 to 18 years and born to 113 obese mothers (BMI: 31 ± 9 kg/m2) with substantial weight loss after biliopancreatic bypass surgery with 45 same-age siblings who were born before maternal surgery (mothers’ BMI: 48 ± 8 kg/m2) and with current population standards. METHODS. In this case series, with >88% follow-up in a tertiary referral center, crosssectional office chart and telephone data on childhood and adolescent weights were transformed to z scores. RESULTS. After maternal surgery, the prevalence of obesity in the offspring decreased by 52% and severe obesity by 45.1%, with no increase in the prevalence of underweight. The z score reduction in obesity was gender specific, with boys reducing from 1.4 ± 1.3 before to 0.57 ± 1.7 after maternal surgery, corrected for birth order. The difference was not significant in girls (0.8 ± 1.3 vs 0.8 ± 1.2). Among children of both genders who were aged 6 to 18 years of age and born after maternal surgery, the prevalence of overweight was reduced to population levels. CONCLUSIONS. Contrary to outcomes after intrauterine under- and overnutrition, the prevalence of overweight and obesity in children of mothers with large voluntary postsurgical weight loss was similar to that in the general population, with no increase in underweight. The results demonstrate the importance of potentially modifiable epigenetic factors in the cause of obesity.


Anesthesiology | 2012

High Tidal Volumes in Mechanically Ventilated Patients Increase Organ Dysfunction after Cardiac Surgery

François Lellouche; Stephanie Dionne; Serge Simard; Jean S. Bussières; François Dagenais

Background: High tidal volumes in patients with acute respiratory distress syndrome and acute lung injury lead to ventilator-induced lung injury and increased mortality. We evaluated the impact of tidal volumes on cardiac surgery outcomes. Methods: We examined prospectively recorded data from 3,434 consecutive adult patients who underwent cardiac surgery. Three groups of patients were defined based on the tidal volume delivered on arrival at the intensive care unit: (1) low: below 10, (2) traditional: 10–12, and (3) high: more than 12 ml/kg of predicted body weight. We assessed risk factors for three types of organ failure (prolonged mechanical ventilation, hemodynamic instability, and renal failure) and a prolonged stay in the intensive care unit. Results: The mean tidal volume/actual weight was 9.2 ml/kg, and the tidal volume/predicted body weight was 11.5 ml/kg. Low, traditional, and high tidal volumes were used in 724 (21.1%), 1567 (45.6%), and 1,143 patients (33.3%), respectively. Independent risks factors for high tidal volumes were body mass index of 30 or more (odds ratio [OR] 6.25; CI: 5.26–7.42; P < 0.001) and female sex (OR 4.33; CI: 3.64–5.15; P < 0.001). In the multivariate analysis, high and traditional tidal volumes were independent risk factors for organ failure, multiple organ failure, and prolonged stay in the intensive care unit. Organ failures were associated with increased intensive care unit stay, hospital mortality, and long-term mortality. Conclusion: Tidal volumes of more than 10 ml/kg are risk factors for organ failure and prolonged intensive care unit stay after cardiac surgery. Women and obese patients are particularly at risk of being ventilated with injurious tidal volumes.


Circulation | 2001

Biological Profiles in Subjects With Recurrent Acute Coronary Events Compared With Subjects With Long-Standing Stable Angina

Peter Bogaty; Paul Poirier; Serge Simard; Luce Boyer; Susan Solymoss; Gilles R. Dagenais

Background—At one end of the clinical spectrum of coronary artery disease (CAD) are subjects who have had repeated acute ischemic events, and at the other end are those with long-standing angina who have never been unstable. This study tests the hypothesis that a specific biological profile can distinguish these 2 extreme groups and predict acute coronary events. Methods and Results—Blood levels of lipoprotein(a), homocysteine, tissue plasminogen activator, plasminogen activator inhibitor-1, C-reactive protein (CRP), fibrinogen, and von Willebrand factor were compared in 3 groups of 50 subjects each: (1) those with previous multiple acute coronary events, (2) age-matched subjects with ≥3 years of stable angina and no prior acute coronary events, and (3) matched controls without evidence of atherosclerotic disease and a normal coronary angiogram. All subjects were followed for 4.0 years. Lipoprotein(a), homocysteine, tissue plasminogen activator, and plasminogen activator inhibitor-1 were similar in both CAD groups and significantly higher than in the control group. However, compared with subjects with long-standing stable angina, those with previous multiple coronary events had higher values of CRP (5.7±5.4 versus 3.0±5.2 mg/L, P =0.012), fibrinogen (3.38±0.75 versus 2.92±0.64 g/L, P =0.001), and von Willebrand factor (1.60±0.55 versus 1.25±0.36 U/mL, P =0.0003). On follow-up, myocardial infarction and unstable angina occurred in 42% of the group with multiple events, 4% of the stable angina group (P <0.0001), and none of the control subjects. In the 100 patients with CAD, CRP was 4.9 mg/L in those with and 1.8 mg/L in those without new instability (P <0.0001). In a multivariate analysis, only CRP distinguished those with follow-up acute coronary events (adjusted odds ratio 5.9, 95% CI 2.0 to 17.9;P =0.002). A baseline CRP >3.5 mg/L had a relative risk of 7.6 (2.6 to 21.7, P =0.0002) for subsequent acute events. Conclusions—An inflammatory biological profile distinguished patients with previous multiple acute coronary events from those with long-standing stable angina and predicted acute coronary instability.


Journal of Gastrointestinal Surgery | 2002

Does bone change after biliopancreatic diversion

Picard Marceau; Simon Biron; Stéfane Lebel; Simon Marceau; Frédéric S. Hould; Serge Simard; Marcel Dumont; Lorraine A. Fitzpatrick

This prospective study evaluated bone changes after biliopancreatic diversion (BPD) consisting of a distal gastrectomy, a 250 cm alimentary channel, and a 50 cm common channel. Thirty-three consecutive patients had clinical, biochemical, and bone mineral density analysis before surgery and 4 and 10 years after surgery. Iliac crest bone biopsies and special tests including parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D (1,25-OH2-D), bone-specific alkaline phosphatase (BAP), and osteocalcin were obtained at surgery and 4 years postoperatively. Over the years, with close metabolic surveillance, additional calcium and vitamin D were given as indicated. After BPD, serum levels of calcium and vitamin D were decreased and serum levels of PTH, BAP, and osteocalcin were increased. Bone turnover and mineralization were both increased. Mean osteoid volume (P < 0.0007) and bone formation rate in relation to bone volume (P < 0.02) were increased. Static measures of bone were altered as follows: cortical thickness decreased (P < 0.01) and trabecular bone volume increased (P < 0.01). Ten years after surgery, overall bone mineral density was unchanged at the hip and was decreased by 4% at the lumbar spine. Overall fracture risk, based on the Z score, was unchanged. Preoperative factors predicting bone loss included menopause, smoking, and preexisting osteopenia. An elevated level of 1,25-OH2-D was also found to be a predictor of future bone loss (r = 0.40; P < 0.002). After surgery, a greater increase in bone markers and bone turnover was associated with an increased risk of bone loss. Although elevated osteocalcin levels were associated with overall bone loss (r = 0.52; P < 0.002), lower albumin levels were associated only with bone loss at hip level (r = 0.44; P < 0.02), whereas lower calcium levels were associated only with the loss at the lumbar spine (r = 0.39; P < 0.02). Ten years after surgery, bone loss at the hip continued to depend on albumin levels (r = 0.37; P < 0.03). We concluded that bone was relatively tolerant to the metabolic changes due to BPD. Provided that there is close surveillance for metabolic disturbances, the use of appropriate supplements, and the avoidance of malnutrition, the beneficial effects of surgery far outweigh the risk of postoperative bone disease.


Journal of the American College of Cardiology | 2008

Clinical Utility of C-Reactive Protein Measured at Admission, Hospital Discharge, and 1 Month Later to Predict Outcome in Patients With Acute Coronary Disease: The RISCA (Recurrence and Inflammation in the Acute Coronary Syndromes) Study

Peter Bogaty; Luce Boyer; Serge Simard; Franz Dauwe; Robert Dupuis; Benoît Verret; Thao Huynh; Fernand Bertrand; Gilles R. Dagenais; James M. Brophy

OBJECTIVES This study was designed to prospectively determine, in patients with an acute coronary syndrome, whether the inflammatory marker, C-reactive protein (CRP), measured at hospital admission, discharge, and 1 month later has incremental value to predict outcomes at 1 year. BACKGROUND The clinical utility of CRP measurements in patients with acute coronary syndromes remains uncertain. Limitations of previous studies have been retrospective design and incomplete adjustment for readily available clinical prognosticators. METHODS The CRP marker was measured at admission, hospital discharge, and 1 month later in consecutive patients hospitalized for acute coronary syndromes in 8 tertiary and secondary hospitals. The primary outcome was a composite of death, nonfatal myocardial infarction (MI), and unstable angina (UA) with electrocardiogram (ECG) changes at 1 year. RESULTS A total of 1,210 patients, age 62 +/- 12 years, 64% with acute myocardial infarction (MI) and 36% with unstable angina (UA), were recruited. At 1 year, the primary outcome occurred in 142 patients (11.7%) and included 58 deaths (4.8%), 79 nonfatal MIs (6.5%), and 26 UA episodes with ECG changes (2.1%). The unadjusted odds ratios (ORs) (95% confidence intervals) of CRP values at admission, hospital discharge, and 1 month later for the occurrence of the primary outcome were 1.20 (1.06 to 1.36), 0.98 (0.85 to 1.14), and 1.23 (1.00 to 1.50), respectively. After multivariate adjustment, ORs were 1.04 (0.91 to 1.20), 0.90 (0.77 to 1.06), and 1.12 (0.93 to 1.34), respectively. The individual components of the primary outcome were also not independently associated with any of the 3 CRP measurements. CONCLUSIONS The modest predictive ability of CRP following admission for an acute coronary syndrome disappeared after adjusting for common clinical variables. This large prospective study does not support the incremental value of measuring CRP in this clinical setting.


Surgery for Obesity and Related Diseases | 2009

Duodenal switch improved standard biliopancreatic diversion: a retrospective study.

Picard Marceau; Simon Biron; Frédéric-Simon Hould; Stéfane Lebel; Simon Marceau; Odette Lescelleur; Laurent Biertho; Serge Simard

BACKGROUND This was a retrospective study, performed 10 years after surgery, to compare the results between biliopancreatic diversion (BPD) with distal gastrectomy (DG) versus BPD with duodenal switch (DS). METHODS Complete follow-up data were available for 96% of patients, allowing a comparison of weight loss, revision, side effects, and complications at 10 years. RESULTS After BPD-DS, weight loss was 25% greater than after BPD-DG (46.8 +/- 21.7 kg versus 37.5 +/- 22 kg, respectively; P <.0001). The need for revision decreased from 18.5% to 2.7% (P <.0001), and the prevalence of vomiting during the previous month was 50% less (23.7-50.6%, P <.0001) after BPD-DS compared with after BPD-DG. Late complications were the same for both procedures. Blood analysis showed that, after BPD-DS, the levels of calcium, iron, and hemoglobin were significantly greater and the parathyroid hormone level was lower than after BPD-DG (71.3 +/- 44.2 versus 103.0 +/- 64.0 ng/L, respectively; P <.0001). CONCLUSION The DS greatly improved the BPD, as it was initially proposed. The use of the DS increased weight loss, decreased the need for revision, resulted in fewer side effects, and improved the absorption of nutrients.


The Lancet Respiratory Medicine | 2016

Combination therapy versus monotherapy for pulmonary arterial hypertension: a meta-analysis

Annie C. Lajoie; Gabriel Lauzière; Jean-Christophe Lega; Yves Lacasse; Sylvie Martin; Serge Simard; Sébastien Bonnet; Steeve Provencher

BACKGROUND Several randomised controlled studies and a previous meta-analysis have reported conflicting results regarding the effect of combined targeted therapy compared with monotherapy for pulmonary arterial hypertension (PAH). We did a systematic review and meta-analysis to assess the effects of a combination of PAH-specific therapies compared with monotherapy on predefined clinical worsening in PAH. METHODS We searched MEDLINE, Embase, and the Cochrane Library for reports published from Jan 1, 1990, to May 31, 2015, of prospective randomised controlled trials of at least 12 weeks that assessed a combination of PAH-specific therapies (upfront and sequential add-on) compared with background PAH-specific monotherapy in patients older than 12 years. We extracted data from the reports, and assessed the primary outcome of risk of clinical worsening, as defined a priori in each trial, using the Mantel-Haenszel method based on a fixed-effects model. FINDINGS Of 2017 studies that we identified from our search, we included 17 (4095 patients) in our analysis. 15 studies assessed clinical worsening and were included in the primary analysis. Combined therapy was associated with significant risk reduction for clinical worsening compared with monotherapy (combined therapy 17% [332 of 1940 patients] vs monotherapy 28% [517 of 1862 patients], risk ratio [RR] 0·65 [95% CI 0·58-0·72], p<0·00001). We noted no heterogeneity between the studies (I(2)=18%, phomogeneity=0·25). A publication bias was suggested by the results of an Egger test (t=-2·3982, p=0·031), but when we excluded the four studies with the highest SEs, the RR for clinical worsening was identical (0·65 [95% CI 0·58-0·73], p<0·00001). INTERPRETATION In our analysis, combined therapy for PAH was associated with a significant reduction in clinical worsening compared with monotherapy. However, our study was limited by the variable definition of clinical worsening among the trials and possible publication bias. Because many patients still had clinical worsening with combination therapy, identification of innovative therapeutic targets for PAH is thus urgently needed. FUNDING None.

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