13 results on '"Kok, Niels F M"'
Search Results
2. Complex Vascular Anatomy in Live Kidney Donation: Imaging and Consequences for Clinical Outcome.
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Kok, Niels F. M., Dols, Leonienke F. C., Hunink, M G. Myriam, Alwayn, Ian P. J., Tran, Khe T. C., Weimar, Willem, and Ijzermans, Jan N. M.
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- 2008
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3. Cost Effectiveness of Laparoscopic Versus Mini-Incision Open Donor Nephrectomy: A Randomized Study.
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Kok, Niels F. M., Adang, Eddy M. M., Hansson, Birgitta M. E., Dooper, Ine M., Weimar, Willem, Van Der Wilt, Gert-Jan, and Ijzermans, Jan N. M.
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- 2007
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4. A comparison of inflammatory, cytoprotective and injury gene expression profiles in kidneys from brain death and cardiac death donors.
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Saat TC, Susa D, Roest HP, Kok NF, van den Engel S, Ijzermans JN, and de Bruin RW
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- Acute Kidney Injury immunology, Acute Kidney Injury metabolism, Acute Kidney Injury pathology, Animals, Apoptosis, Brain Death immunology, Brain Death pathology, Cold Ischemia, Cytoprotection, Delayed Graft Function genetics, Delayed Graft Function immunology, Delayed Graft Function metabolism, Delayed Graft Function pathology, Gene Expression Regulation, Genetic Markers, Inflammation immunology, Inflammation metabolism, Inflammation pathology, Inflammation Mediators metabolism, Kidney immunology, Kidney pathology, Kidney Transplantation adverse effects, Male, Models, Animal, Organ Preservation, Rats, Rats, Inbred BN, Risk Factors, Time Factors, Transcription, Genetic, Acute Kidney Injury genetics, Brain Death metabolism, Gene Expression Profiling methods, Inflammation genetics, Kidney metabolism
- Abstract
Background: The superior long-term survival of kidneys from living donors (LDs) compared with kidneys from donation-after-brain-death (DBD) and donation-after-cardiac-death (DCD) donors is now well established. However, comparative studies on transcriptional changes that occur at organ retrieval and during and after cold ischemia (CI) are sparse., Methods: Using a rat model, we used qRT-PCR to examine expression levels of inflammatory, cytoprotective, and injury genes at different time points after organ retrieval. Cleaved caspase-3 was used to evaluate early apoptosis in DCD and DBD kidneys., Results: Immediately after retrieval, we found massive up-regulation of proinflammatory genes interleukin-1β, interleukin-6, tumor necrosis factor-α, monocyte chemotactic protein-1, P-selectin, and E-selectin in DBD compared with LD and DCD kidneys. A significant increase in the expression of injury markers Kim-1, p21, and the cytoprotective gene heme oxygenase-1 accompanied this. Bax was increased in DCD kidneys, and Bcl-2 was decreased in DBD kidneys. After 2 hr of CI in the LD group and 18 hr in the DBD and DCD groups, gene expression levels were similar to those found after retrieval. During 18 hr of cold storage, expression levels of these genes did not change. In DCD and DBD kidneys, early apoptosis increased after CI., Discussion/conclusion: The gene expression profile in DBD kidneys represents an inflammatory and injury response to brain death. In contrast, DCD kidneys show only mild up-regulation of inflammatory and injury genes. These results may imply why delayed graft function in DCD kidneys does not have the deleterious effect it has on DBD kidneys.
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- 2014
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5. Randomized controlled trial comparing hand-assisted retroperitoneoscopic versus standard laparoscopic donor nephrectomy.
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Dols LF, Kok NF, d'Ancona FC, Klop KW, Tran TC, Langenhuijsen JF, Terkivatan T, Dor FJ, Weimar W, Dooper IM, and Ijzermans JN
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- Adult, Aged, Female, Humans, Male, Middle Aged, Quality of Life, Retroperitoneal Space, Warm Ischemia, Endoscopy methods, Kidney Transplantation, Laparoscopy methods, Living Donors, Nephrectomy methods
- Abstract
Background: Laparoscopic donor nephrectomy (LDN) has become the gold standard for live-donor nephrectomy, as it results in a short convalescence time and increased quality of life. However, intraoperative safety has been debated, as severe complications occur incidentally. Hand-assisted retroperitoneoscopic donor nephrectomy (HARP) is an alternative approach, combining the safety of hand-guided surgery with the benefits of endoscopic techniques and retroperitoneal access. We assessed the best approach to optimize donors' quality of life and safety., Methods: In two tertiary referral centers, donors undergoing left-sided nephrectomy were randomly assigned to HARP or LDN. Primary endpoint was physical function, one of the dimensions of the Short Form-36 questionnaire on quality of life, at 1 month postoperatively. Secondary endpoints included intraoperative events and operation times. Follow-up was 1 year., Results: In total, 190 donors were randomized. Physical function at 1 month follow-up did not significantly differ between groups (estimated difference, 1.79; 95% confidence interval, -4.1 to 7.68; P=0.55). HARP resulted in significantly shorter skin-to-skin time (mean, 159 vs. 188 min; P<0.001), shorter warm ischemia time (2 vs. 5 min; P<0.001) and a lower intraoperative event rate (5% vs. 11%, P=0.117). Length of stay (both 3 days; P=0.135) and postoperative complication rate (8% vs. 8%; P=1.00) were not significantly different. Potential graft-related complications did not significantly differ (6% vs. 13%; P=0.137)., Conclusions: Compared with LDN, left-sided HARP leads to similar quality of life, shorter operating time, and warm ischemia time. Therefore, we recommend HARP as a valuable alternative to the laparoscopic approach for left-sided donor nephrectomy.
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- 2014
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6. Quality of life of elderly live kidney donors.
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Klop KW, Dols LF, Weimar W, Dooper IM, IJzermans JN, and Kok NF
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- Adult, Age Factors, Aged, Chi-Square Distribution, Follow-Up Studies, Humans, Middle Aged, Netherlands, Pain, Postoperative etiology, Pain, Postoperative psychology, Prospective Studies, Recovery of Function, Surveys and Questionnaires, Time Factors, Donor Selection, Kidney Transplantation adverse effects, Living Donors supply & distribution, Nephrectomy adverse effects, Quality of Life
- Abstract
Background: Expanding the use of elderly live donors may help meet the demand for kidney transplants. The aim of this study was to quantify the effect of the surgical procedure on the quality of life (QOL) of elderly donors compared with younger donors., Methods: Alongside three prospective studies (two randomized) running between May 2001 and October 2010, we asked 501 live donors to fill out the Short Form-36 questionnaire preoperatively and at 1, 3, 6, and 12 months postoperatively. We defined live donors 60 years or older as elderly. Between-group analyses regarding QOL were adjusted for baseline values and gender., Results: One hundred thirty-five donors were older and 366 donors were younger than 60 years. The response rate was high, with 87% at 12 months postoperatively. Elderly donors less often scored as American Society of Anaesthesiology classification 1 (60% vs. 81%; P<0.001) indicating a higher rate of minor comorbidity. At 1 month postoperatively, between-group analysis showed a significant advantage in QOL in favor of the elderly group regarding the dimensions "bodily pain" (7 points; P=0.001), "role physical" (18 points; P<0.001), and "vitality" (5 points; P=0.008). At 3 months, "bodily pain" (3 points, P=0.04) and "role physical" (8 points, P=0.02) were still in favor of the older group. At 6 and 12 months, "physical function" was in favor of the younger group (3 and 5 points, respectively; P=0.04 and P<0.001)., Conclusions: This study demonstrates that elderly donors recover relatively fast. The perspective of excellent postoperative QOL may help convince elderly individuals to donate.
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- 2013
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7. Cost-effectiveness of hand-assisted retroperitoneoscopic versus standard laparoscopic donor nephrectomy: a randomized study.
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Klop KW, Kok NF, Dols LF, d'Ancona FC, Adang EM, Grutters JP, and IJzermans JN
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- Adult, Aged, Cost-Benefit Analysis, Female, Humans, Kidney Transplantation economics, Laparoscopy economics, Laparoscopy methods, Living Donors, Male, Middle Aged, Single-Blind Method, Hand-Assisted Laparoscopy economics, Hand-Assisted Laparoscopy methods, Nephrectomy economics, Nephrectomy methods, Tissue and Organ Harvesting economics, Tissue and Organ Harvesting methods
- Abstract
Background: Live kidney donation has a clear economical benefit over dialysis and deceased-donor transplantation. Compared with mini-incision open donor nephrectomy, laparoscopic donor nephrectomy (LDN) is considered cost-effective. However, little is known on the cost-effectiveness of hand-assisted retroperitoneoscopic donor nephrectomy (HARP). This study evaluated the cost-effectiveness of HARP versus LDN., Methods: Alongside a randomized controlled trial, the cost-effectiveness of HARP versus LDN was assessed. Eighty-six donors were included in the LDN group and 82 in the HARP group. All in-hospital costs were recorded. During follow-up, return-to-work and other societal costs were documented up to 1 year. The EuroQol-5D questionnaire was administered up to 1 year postoperatively to calculate quality-adjusted life years (QALYs)., Results: Mean total costs from a healthcare perspective were $8935 for HARP and $8650 for LDN (P = 0.25). Mean total costs from a societal perspective were $16,357 for HARP and $16,286 for LDN (P = 0.79). On average, donors completely resumed their daytime jobs on day 54 in the HARP group and on day 52 in the LDN group (P = 0.65). LDN resulted in a gain of 0.005 QALYs., Conclusions: Absolute costs of both procedures are very low and the differences in costs and QALYs between LDN and HARP are very small. Other arguments, such as donor safety and pain, should determine the choice between HARP and LDN.
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- 2013
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8. Attitudes among surgeons towards live-donor nephrectomy: a European update.
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Klop KW, Dols LF, Kok NF, Weimar W, and Ijzermans JN
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- Attitude to Health, Body Mass Index, Comorbidity, Endoscopy methods, Europe, Health Knowledge, Attitudes, Practice, Humans, Kidney pathology, Kidney Transplantation methods, Living Donors, Surgical Procedures, Operative, Surveys and Questionnaires, Time Factors, Tissue and Organ Harvesting, Nephrectomy methods
- Abstract
Background: The increasing number of living kidney donors in the last decade has led to the development of novel surgical techniques for live-donor nephrectomy. The aim of the present study was to evaluate the current status of the surgical approach in Europe., Methods: A survey was sent to 119 transplant centers in 12 European countries. Questions included the number of donors, the technique used, and the acceptance of donors with comorbidities., Results: Ninety-six centers (81%) replied. The number of living donors per center ranged from 0 to 124. Thirty-one institutions (32%) harvested kidneys using open techniques only. Six centers (6%) applied both endoscopic and open techniques; 59 centers (61%) performed endoscopic donor nephrectomy only. Lack of evidence that endoscopic techniques provide superior results was the main reason for still performing open donor nephrectomy. In seven centers, a lumbotomy is still performed. Seventy-two centers (75%) accept donors with a body mass index of more than 30 kg/m, the median upper limit in these centers was 35 kg/m (range, 31-40). Donors with an American Society of Anesthesiologists classification higher than 1 were accepted in 55% of the centers., Conclusions: Live kidney donation in general and minimally invasive donor nephrectomy in particular are more commonly applied in Northern and Western Europe. However, a classic lumbotomy is still performed in a minority of centers. Because minimally invasive techniques have been proven superior, more attention should be given to educational programs in this field to let many kidney donors benefit.
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- 2012
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9. Spinal or local anesthesia in lichtenstein hernia repair: a randomized controlled trial.
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van Veen RN, Mahabier C, Dawson I, Hop WC, Kok NF, Lange JF, and Jeekel J
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- Activities of Daily Living, Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, Pain Measurement, Prospective Studies, Quality of Life, Time Factors, Anesthesia, Local, Anesthesia, Spinal, Hernia, Inguinal surgery
- Abstract
Background: With established protocols lacking, the choice of anesthetic technique remains arbitrary in inguinal hernia repair. Well-designed studies in this subject are important because of the gap or discrepancy between available scientific evidence and clinical practice., Methods: Between August 2004 and June 2006, a multicenter prospective clinical trial was performed in which 100 patients with unilateral primary inguinal hernia were randomized to spinal or local anesthesia. Clinical examination took place within 2 weeks postoperatively and at 3 months in the outpatient clinic., Results: Analysis of postoperative visual analogue scale scores showed that patients operated under local anesthesia had significant less pain shortly after surgery (P = 0.021). Significantly more urinary retention (P < 0.001) and more overnight admissions (P = 0.004) occurred after spinal anesthesia. Total operating time is significantly shorter in the local anesthesia group (P < 0.001). No significant differences were found between the 2 groups with respect to the activities of daily life and quality of life., Conclusions: Our study provides evidence that local anesthesia is superior to spinal anesthesia in inguinal hernia repair. Local anesthesia in primary, inguinal hernia repairs should be the method of choice.
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- 2008
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10. Psychosocial and physical impairment after mini-incision open and laparoscopic donor nephrectomy: A prospective study.
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Kok NF, Alwayn IP, Tran KT, Hop WC, Weimar W, and Ijzermans JN
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- Adult, Aged, Aged, 80 and over, Fatigue epidemiology, Female, Follow-Up Studies, Humans, Laparoscopy psychology, Male, Middle Aged, Nephrectomy psychology, Postoperative Complications physiopathology, Postoperative Complications psychology, Psychoacoustics, Laparoscopy methods, Living Donors, Nephrectomy methods, Postoperative Complications classification, Quality of Life, Social Adjustment, Tissue and Organ Harvesting methods
- Abstract
Background: The aim of the present study was to prospectively investigate how mini-incision donor nephrectomy (MIDN) and laparoscopic donor nephrectomy (LDN) affected the donor's quality of life and fatigue., Methods: Forty-five donors underwent MIDN and 55 donors underwent LDN. Quality of life and fatigue were recorded preoperatively and four times during one year follow-up on the Short-Form 36 (SF-36) and Multidimensional Fatigue Inventory-20 (MFI-20), respectively., Results: One-year response rates were 89% and 95% following MIDN and LDN, respectively. After MIDN, all dimensions of the SF-36 significantly declined. Most dimensions returned to preoperative values at three months except for "vitality" (six months) and "bodily pain" (12 months). After LDN, the scores of the SF-36 dimensions returned to preoperative values at three months, except for "vitality" and "role physical" (both six months). Between-groups analysis revealed significantly better scores of the SF-36 dimensions "physical function" (P = 0.03) and "bodily pain" (P = 0.04) following LDN at one month postoperatively. Fatigue scores did not significantly differ between the groups at any point in time. General and physical fatigue (MFI-20) remained affected up to one year after either type of surgery. After MIDN, 4% of the donors had returned to work at four weeks postoperatively versus 28% after LDN (P = 0.04). Return to preoperative activity level was not significantly different between groups., Conclusions: Both procedures clearly impact quality of life and fatigue. The beneficial effect on the quality of life and the earlier return to work encourage us to advocate LDN as the surgical approach to be preferred.
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- 2006
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11. The current practice of live donor nephrectomy in Europe.
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Kok NF, Weimar W, Alwayn IP, and Ijzermans JN
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- Europe, Functional Laterality, Humans, Laparoscopy methods, Surveys and Questionnaires, Kidney Transplantation statistics & numerical data, Living Donors statistics & numerical data, Nephrectomy methods, Tissue and Organ Harvesting methods
- Abstract
Background: The increasing number of live kidney donors in the last decade has stimulated interest in the surgical technique of donor nephrectomy. In this study, we evaluated the current status of the surgical approach in European transplant centers., Methods: A questionnaire was sent to 131 centers in 12 European countries. Questions included the number of donors, the technique used, and the inclusion and exclusion criteria for a technique., Results: Ninety-two replies (70%) were included. In the responding centers, approximately 1450 live donor nephrectomies were performed in 2004 (more than 80% of all live kidney donations in these countries). The number of living donors ranged from 0 to 95 per center. Nineteen institutions (21%) removed kidneys using endoscopic techniques only. Twenty-two centers (24%) performed both open and laparoscopic donor nephrectomy. Vessel length, difficult anatomy and right-sided donor nephrectomy were common reasons to choose an open technique. Twelve centers had performed laparoscopic donor nephrectomy but quit their program for various reasons. In 51 centers (55%), only open donor nephrectomy was carried out. Lack of evidence that endoscopic techniques provide better results was the main reason for these centers to stick to an open approach. Incisional hernias occurred after all types of open surgery in up to 30% of the donors per center. Twenty-nine clinics still carry out the classic flank incision., Conclusion: The surgical technique of live donor nephrectomy varies greatly between transplant centers in European countries. To define the optimal surgical approach a European registration of donor nephrectomies would be helpful.
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- 2006
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12. Donor nephrectomy: mini-incision muscle-splitting open approach versus laparoscopy.
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Kok NF, Alwayn IP, Lind MY, Tran KT, Weimar W, and IJzermans JN
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- Adult, Aged, Female, Humans, Male, Middle Aged, Nephrectomy adverse effects, Kidney Transplantation, Laparoscopy methods, Living Donors, Nephrectomy methods
- Abstract
Background: The introduction of laparoscopic donor nephrectomy (LDN) has encouraged the development of less invasive open techniques. Aim of the present study was to compare short-term outcomes between contemporary cohorts of donors who underwent either mini-incision open or laparoscopic kidney donation., Methods: From May 2001 to September 2004 data of all living kidney donations and transplantations were prospectively collected. Fifty-one donors underwent mini-incision, muscle-splitting open donor nephrectomy (MIDN) and 49 donors underwent LDN., Results: Baseline characteristics of donors and recipients in the study groups were comparable except for donors' gender. Median incision length in MIDN was 10.5 cm. In two patients LDN was converted to open. MIDN resulted in significantly shorter warm ischemia and operation time (2.5 vs. 6.5 min and 157 vs. 240 min respectively). During MIDN, donors had more blood loss (200 vs. 120 ml, P=0.02). Disposables used for MIDN were cheaper (328 vs. 1784 Euros). In the LDN group 4 (8%) major intraoperative and 2 (4%) major postoperative complications occurred versus no major complications in the MIDN group. Morphine requirement, pain and nausea perception, and time to dietary intake did not significantly differ between the groups. Following MIDN, donors were discharged later (4 vs. 3 days, P=0.02). Transplantation of kidneys procured by either approach led to a similar decline in serum creatinine throughout the first year. One-year graft survival was 100% following MIDN and 86% following LDN (P=0.005)., Conclusion: MIDN and LDN both lead to satisfactory results. Both techniques can be used to expand living donor programs.
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- 2006
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13. A meta-analysis of safety and effectiveness of perioperative beta-blocker use for the prevention of cardiac events in different types of noncardiac surgery.
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Schouten O, Shaw LJ, Boersma E, Bax JJ, Kertai MD, Feringa HH, Biagini E, Kok NF, Urk Hv, Elhendy A, and Poldermans D
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- Death, Sudden, Cardiac etiology, Humans, Myocardial Ischemia etiology, Surgical Procedures, Operative adverse effects, Adrenergic beta-Antagonists therapeutic use, Death, Sudden, Cardiac prevention & control, Myocardial Ischemia prevention & control, Perioperative Care methods
- Abstract
Objective: Perioperative beta-blocker therapy has been proposed to improve outcome. Most of the trials conducted, however, lacked statistical power to evaluate the incidence of hard cardiac events and the relationship to the type of surgery. Therefore, we conducted a meta-analysis of all randomized controlled trials in which beta-blocker therapy was evaluated., Methods: An electronic search of published reports on Medline was undertaken to identify studies published between January 1980 and November 2004 in English language journals. All studies reported on at least one of three endpoints: perioperative myocardial ischemia, perioperative nonfatal myocardial infarction, and cardiac mortality. Type of surgery, defined as low, intermediate, and high risk according to the American College of Cardiology/American Heart Association guidelines, was noted., Results: In total, 15 studies were identified, which enrolled 1,077 patient. No significant differences were observed in baseline clinical characteristics between patients randomized to beta-blocker therapy and control/placebo. Beta-blocker therapy was associated with a 65% reduction in perioperative myocardial ischemia (11.0% vs. 25.6%; odds ratio 0.35, 95% confidence interval 0.23-0.54; P<0.001). Furthermore, a 56% reduction in myocardial infarction (0.5% vs. 3.9%, odds ratio 0.44, 95% confidence interval 0.20-0.97; P=0.04) and a 67% reduction (1.1% vs. 6.1%, odds ratio 0.33, 95% confidence interval 0.17-0.67; P=0.002) in the composite endpoint of cardiac death and nonfatal myocardial infarction were observed. No statistical evidence was observed for heterogeneity in the treatment effect in subgroups according to type of surgery (P for heterogeneity 0.2)., Conclusion: This meta-analysis shows that beta-blocker use in noncardiac surgical procedures is associated with a significant reduction of perioperative cardiac adverse events.
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- 2006
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