Harry van Goor

Universitair Medisch Centrum Groningen, Groningen, Groningen, Netherlands

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Publications (522)2324.76 Total impact

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    ABSTRACT: A clear definition of "complex (abdominal wall) hernia" is missing, though the term is often used. Practically all "complex hernia" literature is retrospective and lacks proper description of the population. There is need for clarification and classification to improve patient care and allow comparison of different surgical approaches. The aim of this study was to reach consensus on criteria used to define a patient with "complex" hernia. Three consensus meetings were convened by surgeons with expertise in complex abdominal wall hernias, aimed at laying down criteria that can be used to define "complex hernia" patients, and to divide patients in severity classes. To aid discussion, literature review was performed to identify hernia classification systems, and to find evidence for patient and hernia variables that influence treatment and/or prognosis. Consensus was reached on 22 patient and hernia variables for "complex" hernia criteria inclusion which were grouped under four categories: "Size and location", "Contamination/soft tissue condition", "Patient history/risk factors", and "Clinical scenario". These variables were further divided in three patient severity classes ('Minor', 'Moderate', and 'Major') to provide guidance for peri-operative planning and measures, the risk of a complicated post-operative course, and the extent of financial costs associated with treatment of these hernia patients. Common criteria that can be used in defining and describing "complex" (abdominal wall) hernia patients have been identified and divided under four categories and three severity classes. Next step would be to create and validate treatment algorithms to guide the choice of surgical technique including mesh type for the various complex hernias.
    Hernia 10/2013; · 2.09 Impact Factor
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    ABSTRACT: In 2013 Guidelines on diagnosis and management of ASBO have been revised and updated by the WSES Working Group on ASBO to develop current evidence-based algorithms and focus indications and safety of conservative treatment, timing of surgery and indications for laparoscopy.Recommendations: In absence of signs of strangulation and history of persistent vomiting or combined CT-scan signs (free fluid, mesenteric edema, small-bowel feces sign, devascularization) patients with partial ASBO can be managed safely with NOM and tube decompression should be attempted. These patients are good candidates for Water-Soluble-Contrast-Medium (WSCM) with both diagnostic and therapeutic purposes. The radiologic appearance of WSCM in the colon within 24 hours from administration predicts resolution. WSCM maybe administered either orally or via NGT both immediately at admission or after failed conservative treatment for 48 hours. The use of WSCM is safe and reduces need for surgery, time to resolution and hospital stay.NOM, in absence of signs of strangulation or peritonitis, can be prolonged up to 72 hours. After 72 hours of NOM without resolution, surgery is recommended.Patients treated non-operatively have shorter hospital stay, but higher recurrence rate and shorter time to re-admission, although the risk of new surgically treated episodes of ASBO is unchanged. Risk factors for recurrences are age <40 years and matted adhesions. WSCM does not decrease recurrence rates or recurrences needing surgery.Open surgery is often used for strangulating ASBO as well as after failed conservative management. In selected patients and with appropriate skills, laparoscopic approach is advisable using open access technique. Access in left upper quadrant or left flank is the safest and only completely obstructing adhesions should be identified and lysed with cold scissors. Laparoscopic adhesiolysis should be attempted preferably if first episode of SBO and/or anticipated single band. A low threshold for open conversion should be maintained.Peritoneal adhesions should be prevented. Hyaluronic acid-carboxycellulose membrane and icodextrin decrease incidence of adhesions. Icodextrin may reduce the risk of re-obstruction. HA cannot reduce need of surgery.Adhesions quantification and scoring maybe useful for achieving standardized assessment of adhesions severity and for further research in diagnosis and treatment of ASBO.
    World Journal of Emergency Surgery 10/2013; 8(1):42. · 1.06 Impact Factor
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    ABSTRACT: To estimate the disease burden of the most important complications of postoperative abdominal adhesions: small bowel obstruction, difficulties at reoperation, infertility, and chronic pain. Systematic review and meta-analyses. Searches of PubMed, Embase, and Central, from January 1990 to December 2012, without restrictions to publication status or language. All types of studies reporting on the incidence of adhesion related complications were considered. The primary outcome was the incidence of adhesive small bowel obstruction in patients with a history of abdominal surgery. Secondary outcomes were the incidence of small bowel obstruction by any cause, difference in operative time, enterotomy during adhesiolysis, and pregnancy rate after abdominal surgery. Subgroup and sensitivity analyses were done to study the robustness of the results. A random effects model was used to account for heterogeneity between studies. We identified 196 eligible papers. Heterogeneity was considerable for almost all meta-analyses. The origin of heterogeneity could not be explained by study design, study quality, publication date, anatomical site of operation, or operative technique. The incidence of small bowel obstruction by any cause after abdominal surgery was 9% (95% confidence interval 7% to 10%; I(2)=99%). the incidence of adhesive small bowel obstruction was 2% (2% to 3%; I(2)=93%); presence of adhesions was generally confirmed by emergent reoperation. In patients with a known cause of small bowel obstruction, adhesions were the single most common cause (56%, 49% to 64%; I(2)=96%). Operative time was prolonged by 15 minutes (95% confidence interval 9.3 to 21.1 minutes; I(2)=85%) in patients with previous surgery. Use of adhesiolysis resulted in a 6% (4% to 8%; I(2)=89%) incidence of iatrogenic bowel injury. The pregnancy rate after colorectal surgery in patients with inflammatory bowel disease was 50% (37% to 63%; I(2)=94%), which was significantly lower than the pregnancy rate in medically treated patients (82%, 70% to 94%; I(2)=97%). This review provides detailed and systematically analysed knowledge of the disease burden of adhesions. Complications of postoperative adhesion formation are frequent, have a large negative effect on patients' health, and increase workload in clinical practice. The quantitative effects should be interpreted with caution owing to large heterogeneity. The review protocol was registered through PROSPERO (CRD42012003180).
    BMJ (online) 10/2013; 347:f5588. · 16.38 Impact Factor
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    ABSTRACT: Formation of adhesions after peritoneal surgery results in high morbidity. Barriers to prevent adhesion are seldom applied, despite their ability to reduce the severity of adhesion formation. We evaluated the benefits and harms of four adhesion barriers that have been approved for clinical use. In this systematic review and meta-analysis, we searched PubMed, CENTRAL, and Embase for randomised clinical trials assessing use of oxidised regenerated cellulose, hyaluronate carboxymethylcellulose, icodextrin, or polyethylene glycol in abdominal surgery. Two researchers independently identified reports and extracted data. We compared use of a barrier with no barrier for nine predefined outcomes, graded for clinical relevance. The primary outcome was reoperation for adhesive small bowel obstruction. We assessed systematic error, random error, and design error with the error matrix approach. This study is registered with PROSPERO, number CRD42012003321. Our search returned 1840 results, from which 28 trials (5191 patients) were included in our meta-analysis. The risks of systematic and random errors were low. No trials reported data for the effect of oxidised regenerated cellulose or polyethylene glycol on reoperations for adhesive small bowel obstruction. Oxidised regenerated cellulose reduced the incidence of adhesions (relative risk [RR] 0·51, 95% CI 0·31-0·86). Some evidence suggests that hyaluronate carboxymethylcellulose reduces the incidence of reoperations for adhesive small bowel obstruction (RR 0·49, 95% CI 0·28-0·88). For icodextrin, reoperation for adhesive small bowel obstruction did not differ significantly between groups (RR 0·33, 95% CI 0·03-3·11). No barriers were associated with an increase in serious adverse events. Oxidised regenerated cellulose and hyaluronate carboxymethylcellulose can safely reduce clinically relevant consequences of adhesions. None.
    The Lancet 09/2013; · 39.21 Impact Factor
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    ABSTRACT: Depending on the glycan structure, proteoglycans can act as coreceptors for growth factors. We hypothesized that proteoglycans and their growth factor ligands orchestrate tissue remodeling in chronic transplant dysfunction. We have previously shown perlecan to be selectively up-regulated in the glomeruli and arteries in a rat renal transplantation model. Using the same model, here we present quantitative RT-PCR profiling data on proteoglycans and growth factors from laser-microdissected glomeruli, arterial tunicae mediae, and neointimae at 12 weeks after transplantation. In glomeruli and neointimae of allografts, selective induction of the matrix heparan sulfate proteoglycan perlecan was observed, along with massive accumulation of fibroblast growth factor 2 (FGF2). Profiling the heparan sulfate polysaccharide side chains revealed conversion from a non-FGF2-binding heparan sulfate phenotype in control and isografted kidneys toward a FGF2-binding phenotype in allografts. In vitro experiments with perlecan-positive rat mesangial cells showed that FGF2-induced proliferation is dependent on sulfation and can be inhibited by exogenously added heparan sulfate. These findings indicate that matrix proteoglycans such as perlecan serve as functional docking platforms for FGF2 in chronic transplant dysfunction. We speculate that heparin-like glycomimetics could be a promising intervention to retard development of glomerulosclerosis and neointima formation in chronic transplant dysfunction.
    American Journal Of Pathology 09/2013; · 4.60 Impact Factor
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    ABSTRACT: Thoracoscopic splanchnicectomy (TS) is a minimally invasive intervention to relieve pain in patients with chronic pancreatitis (CP) with equivocal results. Preoperative opioid use seems to impair TS outcome but this has not been investigated in a systematic matter. We searched PubMed, EMBASE, and The Cochrane Library for studies on the outcome of TS in CP patients. Studies with ≥5 patients and a follow-up of ≥12 months were included. Success was defined as the proportion of patients free of opioids or who had a reduction of ≥4 points on a pain scale. The effect of opioid use on the success rate of TS was analyzed by uni- and multivariate regression. Sixteen studies with 484 patients were included in our review. The mean (±SD) age of the patients was 44 ± 4.3 years and 66 % were male. Median follow-up period was 21 months (IQR 14-35). Median preoperative opioid use was 85 % (IQR 54-100 %). After TS, a median of 49 % (IQR 22-75 %) of patients were free of opioids at end of follow-up. The median success rate was 62 % (IQR 48-86 %). Mean success rate in studies in which ≤50 % of the patients used opioids preoperatively was 81 % (SD ± 21) compared to 60 % (SD ± 15) for other studies (p = 0.049). Higher age, male gender, and lower rates of preoperative opioid use were associated with a higher success rate (p = 0.003, 0.047, and 0.017, respectively). Multivariate regression, including age, gender, preoperative opioid use, and duration of follow-up, identified age and preoperative opioid use as independent predictors of success after TS (both p = 0.002). Preoperative opioid use is associated with a worse outcome after TS in CP patients. To optimize outcome, use of TS may be considered at an earlier stage in the treatment of patients with CP before prolonged opioid therapy.
    Surgical Endoscopy 09/2013; · 3.31 Impact Factor
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    ABSTRACT: Aging of the kidney is associated with renal damage, in particular mesangial matrix expansion (MME). Identifying the genes involved in this process will help to unravel the mechanisms of aging and aid in the design of novel therapeutic modalities aimed at prevention and regression. In this study, structural changes in glomeruli of 24 inbred mouse strains were characterized in male mice at 6, 12, and 20 months of age. Haplotype association mapping was used to determine genetic loci associated with the presence of MME at 20 months. This analysis identified a significant association with a 200-kb haplotype block on chromosome 6 containing Far2. Sequencing revealed that mouse strains with MME contain a 9-bp sequence in the 5' untranslated region of Far2 that is absent in most of the strains without MME. Real-time PCR showed a two-fold increase in the expression of Far2 in the kidneys of strains with the insert, and subsequent experiments performed in vitro with luciferase reporter vectors showed that this sequence difference causes differential expression of Far2. Overexpression of Far2 in a mouse mesangial cell line induced upregulation of platelet activating factor and the fibrotic marker TGF-β. This upregulation of MME-promoting factors may result, in part, from the FAR2-catalyzed reduction of fatty acyl-coenzyme A to fatty alcohols, which are possible precursors of platelet activating factor. Overall, these data suggest the identification of a novel pathway involved in renal aging that may yield therapeutic targets for reducing MME.
    Journal of the American Society of Nephrology 09/2013; · 9.47 Impact Factor
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    ABSTRACT: Emerging work demonstrates the dual regulation of mitochondrial function by hydrogen sulfide (H2 S), including, at lower concentrations, a stimulatory effect as an electron donor, and, at higher concentrations, an inhibitory effect on cytochrome C oxidase. In the current article we overview the pathophysiological and therapeutic aspects of these processes. During cellular hypoxia/acidosis, the inhibitory effect of H2 S on Complex IV is enhanced, which may shift the balance of H2 S from protective to deleterious. Several pathophysiological conditions are associated with an overproduction of H2 S (e.g. sepsis), while in other disease states H2 S levels and H2 S bioavailability are reduced and its therapeutic replacement is warranted (e.g. diabetic vascular complications). Moreover, recent studies demonstrate that colorectal cancer cells upregulate the H2 S-producing enzyme cystathionine β-synthase (CBS), and utilize its product, H2 S, as a metabolic fuel and tumor-cell survival factor; pharmacological CBS inhibition or genetic CBS silencing suppress cancer cell bioenergetics and suppresses cell proliferation and cell chemotaxis. In the last chapter of the current article, we overview the field of H2 S-induced therapeutic 'suspended animation', a concept in which a temporary pharmacological reduction in cell metabolism is achieved, producing a decreased oxygen demand for the experimental therapy of critical illness and/or organ transplantation.
    British Journal of Pharmacology 09/2013; · 5.07 Impact Factor
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    ABSTRACT: Spinocerebellar ataxia type 3 (SCA3) is a polyglutamine (polyQ) disorder caused by a CAG repeat expansion in the ataxin3-gene. The polyQ expansion leads to neuronal dysfunction and cell death. Besides proteotoxic stress, mitochondrial dysfunction, oxidative stress, inflammation, apoptosis and a disturbed calcium homeostasis are thought to contribute to the multifaceted pathogenesis of SCA3. Hydrogen sulfide (H2S) is endogenously produced by cystathionine γ-lyase (CSE), cystathionine β-synthase and 3-mercaptopyruvate sulfurtransferase and has crucial physiological functions in the central nervous system. It has anti-oxidative, anti-inflammatory and anti-apoptotic properties and regulates calcium homeostasis, making it an attractive candidate to intervene in the damaging processes of SCA3. We therefore investigated the protective role of overexpression of endogenous CSE using a Drosophila melanogaster model of SCA3.
    Nitric Oxide 09/2013; 31S2:S32-S33. · 3.18 Impact Factor
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    ABSTRACT: Although several methods to measure hydrogen sulfide (H2S) are available, the physiological baseline H2S serum concentrations remain highly variable and method-dependent. While modifying the classic methylene blue (MB) method in order to improve the detection of serum H2S levels, we also probed the potential sulfur-binding characteristics of serum albumin.
    Nitric Oxide 09/2013; 31 Suppl 2:S55. · 3.18 Impact Factor
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    ABSTRACT: The CBS gene regulates the expression of cystathionine beta-synthase (CBS), a key enzyme in the production of hydrogen sulfide (H2S) by conversion of homocysteine (Hcy). H2S is a gasotransmitter that protects cells against ischemic damage by exerting vasodilatory, anti-inflammatory and antioxidant effects. Both renal transplantation and preeclampsia (PE) are conditions marked by ischemia. Renal ischemia/reperfusion impairs CBS activity and consequently H2S production. Partial restoration of CBS activity causes an increase in H2S levels and a reduction of ischemia/reperfusion damage. Also, H2S is involved in placental vascular tone regulation. Furthermore, preeclamptic women have hyperhomocysteinemia and a decreased placental expression of the CBS gene. We therefore hypothesize that variations in the CBS gene caused by single nucleotide polymorphisms (SNPs) affect both susceptibility to ischemic damage in renal transplantation and the onset of PE.
    Nitric Oxide 09/2013; 31 Suppl 2:S44-5. · 3.18 Impact Factor
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    ABSTRACT: Background: The incidence of acute left-sided colonic diverticulitis (ACD) is increasing in the Western world. To improve the quality of patient care, a guideline for diagnosis and treatment of diverticulitis is needed. Methods: A multidisciplinary working group, representing experts of relevant specialties, was involved in the guideline development. A systematic literature search was conducted to collect scientific evidence on epidemiology, classification, diagnostics and treatment of diverticulitis. Literature was assessed using the classification system according to an evidence-based guideline development method, and levels of evidence of the conclusions were assigned to each topic. Final recommendations were given, taking into account the level of evidence of the conclusions and other relevant considerations such as patient preferences, costs and availability of facilities. Results: The natural history of diverticulitis is usually mild and treatment is mostly conservative. Although younger patients have a higher risk of recurrent disease, a higher risk of complications compared to older patients was not found. In general, the clinical diagnosis of ACD is not accurate enough and therefore imaging is indicated. The triad of pain in the lower left abdomen on physical examination, the absence of vomiting and a C-reactive protein >50 mg/l has a high predictive value to diagnose ACD. If this triad is present and there are no signs of complicated disease, patients may be withheld from further imaging. If imaging is indicated, conditional computed tomography, only after a negative or inconclusive ultrasound, gives the best results. There is no indication for routine endoscopic examination after an episode of diverticulitis. There is no evidence for the routine administration of antibiotics in patients with clinically mild uncomplicated diverticulitis. Treatment of pericolic or pelvic abscesses can initially be treated with antibiotic therapy or combined with percutaneous drainage. If this treatment fails, surgical drainage is required. Patients with a perforated ACD resulting in peritonitis should undergo an emergency operation. There is an ongoing debate about the optimal surgical strategy. Conclusion: Scientific evidence is scarce for some aspects of ACD treatment (e.g. natural history of ACD, ACD in special patient groups, prevention of ACD, treatment of uncomplicated ACD and medical treatment of recurrent ACD), leading to treatment being guided by the surgeon's personal preference. Other aspects of the management of patients with ACD have been more thoroughly researched (e.g. imaging techniques, treatment of complicated ACD and elective surgery of ACD). This guideline of the diagnostics and treatment of ACD can be used as a reference for clinicians who treat patients with ACD.
    Digestive surgery 08/2013; 30(4-5):278-292. · 1.37 Impact Factor
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    Hypertension 08/2013; · 7.63 Impact Factor
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    ABSTRACT: The aim of the present study was to investigate whether patients with persistent pain after breast cancer treatment show an enhanced and slowed dominant alpha activity in their electroencephalogram (EEG) recorded during rest in comparison with patients that also had undergone breast cancer treatment but do not have pain. The spontaneous EEG was recorded during rest and before painful stimulation of the calf and analyzed with spectral analysis (Fast Fourier Transformation). Outcome measures, i.e., alpha indices (center of gravity and overall amplitude), were statistically tested between patients with and without persistent pain. In comparison with patients without pain, patients with persistent pain after breast cancer treatment show more alpha activity in their spontaneous EEG observed from parietal-occipital brain regions. Persistent pain after breast cancer treatment affects spontaneous brain activity, which might influence cognitive functioning.
    Pain Medicine 08/2013; · 2.24 Impact Factor
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    ABSTRACT: The protective, nonerythropoietic effects of erythropoietin (EPO) have become evident in preclinical models in renal ischaemia/reperfusion injury and kidney transplantation. However, four recently published clinical trials using high-dose EPO treatment following renal transplantation did not reveal any protective effect for short-term renal function and even reported an increased risk of thrombosis. This review focusses on the current status of protective pathways mediated by EPO, the safety concerns using high EPO dosage and discusses the discrepancies between pre-clinical and clinical studies. The protective effects are mediated by binding of EPO to a heteromeric receptor complex consisting of two β-common receptors and two EPO receptors. An important role for the activation of endothelial nitric oxide synthase is proposed. EPO-mediated cytoprotection still has enormous potential. However, only nonerythropoietic EPO derivatives may induce protection without increasing the risk of cardiovascular events. In preclinical models, nonerythropoietic EPO derivatives, such as carbamoylated EPO and ARA290, have been tested. These EPO derivatives improve renal function and do not affect erythropoiesis. Therefore, nonerythropoietic EPO derivatives may be able to render EPO-mediated cytoprotection useful and beneficial for clinical transplantation.
    Transplant International 08/2013; · 3.16 Impact Factor
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    ABSTRACT: The aim of this study was to examine the quality and quantity of feedback and instruction from faculty members during an acute trauma surgery team training using a newly designed observational feedback instrument. During the training, 11 operating teams, each consisting of 1 instructor coaching 2 trainees, were videotaped and audiotaped. Forty-five minutes of identical operating scenarios were reviewed and analyzed. Using a new observational feedback instrument, feedback and instruction, containing different levels of specific information related to technical and nontechnical skills, were noted. Instructors more often provided instruction (25.8 ± 10.6 times) than feedback (4.4 ± 3.5 times). Most feedback and instruction contained either nonspecific or less specific information and referred to technical skills. Instructors addressed communication skills more specifically. Coaching by faculty members predominantly contained unspecific instructions regarding technical skills. The observational feedback instrument enabled scoring of the coaching activities.
    American journal of surgery 07/2013; · 2.36 Impact Factor
  • Annals of surgery 06/2013; · 7.19 Impact Factor
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    J F Meis, H van Goor, P E Verweij
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    ABSTRACT: Chronic pancreatitis is an inflammatory disease of the pancreas with abdominal pain as the most prominent symptom. Adequate treatment of patients with chronic pancreatitis remains a major challenge, mainly because of the lack of evidence-based treatment protocols. The primary goal of treatment is to achieve long-term pain relief, control of the complications associated with the disease, and to restore the quality of life. Currently, a conservative step-up approach is often used for the treatment of pain; progression to severe and intractable pain is considered necessary before invasive treatment is considered. Recent studies, however, suggest that surgical intervention should not be considered only as last-resort treatment, since it can mitigate disease progression, achieve excellent pain control, and preserve pancreatic function. In this review, we present a state-of-the art overview of endoscopic and surgical treatment options for patients with painful chronic pancreatitis, and elaborate on the timing of surgery.
    Digestive surgery 04/2013; 30(1):35-50. · 1.37 Impact Factor
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    ABSTRACT: OBJECTIVE: Adhesions and related complications lead to substantially increased morbidity and mortality which increase medical costs. We investigated the awareness of adhesions among Dutch gynaecologists and gynaecology residents. STUDY DESIGN: A survey, assessing knowledge and opinion about adhesions, was sent to a randomly selected group of 381 gynaecologists and 256 residents. In addition, the informed consent process and application of anti-adhesive agents were questioned. RESULTS: The response rate was 56.9%. Complications due to adhesions were highly underestimated, leading to low knowledge scores (mean score 35.1%). Of all respondents 73.8% agreed that adhesions exert a clinically relevant and negative effect, but only 51.2% expressed a positive opinion on adhesion prevention. This correlated with a stronger belief in the clinically relevant and negative effects of adhesions and the opinion that adhesion prevention belongs to standard care (ρ=0.212, p<0.001; ρ=0.495, p<0.001). Of all respondents 31.4% expressed a positive attitude towards anti-adhesive agents and 19.8% expressed a negative one. A negative attitude correlated with a negative view in terms of cost-benefits (ρ=0.245, p<0.001). Although 43.5% had used anti-adhesive agents in the past year, 20.9% had used them before but stopped using agents in the past year. Only 5.2% routinely included adhesions or related morbidity in the informed consent. CONCLUSIONS: Awareness of adhesions is limited and informed consent is provided inadequately. Implementing adhesion prevention is related with awareness of adhesions. These findings underline the need to embed adhesions, related morbidity and prevention in educational programmes.
    European journal of obstetrics, gynecology, and reproductive biology 04/2013; · 1.97 Impact Factor

Publication Stats

9k Citations
2,324.76 Total Impact Points


  • 1987–2014
    • Universitair Medisch Centrum Groningen
      • • Department of Pathology and Medical Biology
      • • Department of Internal Medicine
      • • Department of Pediatrics
      • • Department of Surgery
      Groningen, Groningen, Netherlands
  • 1985–2014
    • University of Groningen
      • • Department of Pathology and Medical Biology
      • • Department of Internal Medicine
      • • Department of Nephrology
      • • Department of Surgery
      • • Laboratory for Medical Microbiology
      • • Liver, Digestive and Metabolic Diseases Research Laboratory
      • • Department of Sociology
      Groningen, Groningen, Netherlands
  • 2013
    • The Jackson Laboratory
      Bar Harbor, Maine, United States
    • Aalborg University Hospital
      • Department of Gastroenterology and Hepatology
      Aalborg, Region North Jutland, Denmark
    • St Jansdal Hospital
      Harderwijk, Gelderland, Netherlands
  • 2009–2013
    • Renmin University of China
      Peping, Beijing, China
    • Orbis Medisch Centrum
      Sittard, Limburg, Netherlands
  • 2000–2013
    • Radboud University Nijmegen
      • Department of Surgery
      Nijmegen, Provincie Gelderland, Netherlands
    • VU University Amsterdam
      • Department of Surgery
      Amsterdamo, North Holland, Netherlands
    • University of California, Davis
      • Department of Internal Medicine
      Davis, CA, United States
  • 1998–2013
    • Radboud University Medical Centre (Radboudumc)
      • Department of Human Genetics
      Nymegen, Gelderland, Netherlands
    • Philadelphia ZOO
      Philadelphia, Pennsylvania, United States
  • 2012
    • VU University Medical Center
      • Department of Molecular Cell Biology and Immunology
      Amsterdam, North Holland, Netherlands
    • Aarhus University Hospital
      • Department of Hepatology and Gastroenterology
      Aarhus, Central Jutland, Denmark
  • 2006–2012
    • University Medical Center Utrecht
      • Department of Surgery
      Utrecht, Provincie Utrecht, Netherlands
    • National and Kapodistrian University of Athens
      • Division of Surgery V
      Athens, Attiki, Greece
  • 2010
    • Jeroen Bosch Ziekenhuis
      Hertogenbosch, North Brabant, Netherlands
  • 1993–2006
    • Universiteit Utrecht
      • • Division of Pharmacology
      • • University Medical Center Utrecht
      Utrecht, Provincie Utrecht, Netherlands
  • 2003
    • Johns Hopkins Medicine
      Baltimore, Maryland, United States
    • Rijnstate Hospital
      Arnheim, Gelderland, Netherlands
  • 2002
    • Maastricht University
      Maestricht, Limburg, Netherlands
  • 1999
    • Indiana University of Pennsylvania
      • Department of Criminology
      Indiana, Pennsylvania, United States
  • 1997
    • Penn State Hershey Medical Center and Penn State College of Medicine
      • Department of Medicine
      Hershey, PA, United States