| 1. |
- Lundgren, Linda, 1973-
(författare)
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Incidental Gallbladder Cancer : Incidence, predictors, management and outcome in a Swedish population
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Cholecystectomy is a common surgical procedure and incidental gallbladder cancer is a rare and unexpected finding at a cholecystectomy performed upon benign indications. Whether to perform routine or selective histopathology of the gallbladder specimen is still a subject for discussion. The prognosis of gallbladder cancer is largely affected by tumour stage and treatment.Aims: The overall aim was to study whether routine histological examination of the gallbladder specimen is of clinical and health economic value; determine if there are any predictive factors of incidental gallbladder cancer at benign cholecystectomy and compare the management and outcome of incidental gallbladder cancer patients in Sweden.Methods: All studies were based on registry data from GallRiks (The Swedish Registry for Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography) between 2007 and 2016, with some modifications between studies. Complemental cross-linkage was made to national registries, and medical records were reviewed. Papers I, II and III were population-based observational studies with prospectively and retrospectively collected data. Paper IV was a health economic evaluation based on the results from papers I and III.Results and conclusions: Hospitals submitting >75 per cent of gallbladder specimens diagnosed a higher proportion of incidental gallbladder cancer than did hospitals submitting ≤25 per cent of samples (paper I). Incidental gallbladder cancer was more prevalent in older patients, women and patients with acute or previous cholecystitis, as well as ongoing jaundice. The risk model based on predictive preoperative factors was further improved by adding a macroscopic assessment of the gallbladder (paper II). Predictive factors for gallbladder cancer appeared to have an impact on which specimens were submitted in hospitals with a selective approach of histopathology (paper I). For pT2 and pT3 patients, re-resection improved diseasespecific survival, although these groups differed in terms of age and comorbidity (paper III). Residual disease was an independent factor for impaired survival. A change to routine histopathology of gallbladder specimens in Sweden would lead to increased costs with little improved health outcomes. Instead, a more standardized approach to selective histology would be needed (paper IV).
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| 2. |
- Lundgren, Linda, et al.
(författare)
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Are Incidental Gallbladder Cancers Missed with a Selective Approach of Gallbladder Histology at Cholecystectomy?
- 2018
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Ingår i: World Journal of Surgery. - : Springer Science and Business Media LLC. - 0364-2313 .- 1432-2323. ; 42:4, s. 1092-1099
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Tidskriftsartikel (refereegranskat)abstract
- Background: Incidental gallbladder cancer (IGBC) is an unexpected finding when a cholecystectomy is performed upon a benign indication, and the use of routine or selective histological analysis of gallbladder specimen is still debated. The aim of this study was to investigate whether the proportion of submitted gallbladder specimens for pathological investigation influences the proportion of IGBC found, and what possible factors preoperatively or perioperatively could influence the selection process. Methods: All cholecystectomies between January 2007 and September 2014 registered in the Swedish Registry of Gallstone Surgery and ERCP (GallRiks) were included. Proportion of histological analysis was divided into four subgroups (0–25%, >25–50%, >50–75%, >75–100%). Results: A total of 81,349 cholecystectomies were registered, and 36,010 (44.3%) gallbladder specimens were sent for histological analysis. A total of 213 cases of IGBC were discovered, which constituted 0.26% of all cholecystectomies performed and 0.59% of the number of gallbladder specimens sent for histological analysis. Hospitals submitting >75–100% of the gallbladder specimens had significantly more IGBC/1000 cholecystectomies performed (p = 0.003). Hospitals with the most selective approach had a significantly higher proportion of IGBC/1000 gallbladders that were sent for histological analysis (p < 0.001). Factors such as higher age (p < 0.001), female gender (p = 0.048) and macroscopic cholecystitis (p < 0.001) were more common in gallbladder specimens from hospitals that had a selective approach to histological analysis. Conclusion: A routine approach to histological analysis in cholecystectomies with a benign indication for surgery can uncover a higher proportion of IGBC cases. When a selective approach is used, risk factors should be taken into account.
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| 3. |
- Jaafar, Gona, et al.
(författare)
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Disparities in the regional, hospital and individual levels of antibiotic use in gallstone surgery in Sweden
- 2017
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Ingår i: BMC Surgery. - : Springer Science and Business Media LLC. - 1471-2482. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: Antimicrobial resistance may be promoted by divergent routines and lack of conformity in antibiotic treatment, especially regarding the practice of antibiotic prophylaxis. The aim of the present study was to assess differences in gallstone surgery regarding antibiotic use in Sweden.Methods: The study was based on data from the Swedish Register for Gallstone Surgery and ERCP (GallRiks) 2005-2015. Funnel plots were used to test impact of grouping factors, including, hospital and surgeon and to identify units that deviated from the rest of the population.Results: After adjusting for cofounders including age, gender, ASA classification, indication for surgery, operation time, gallbladder perforation and emergency status, there were 0/21 (0%) at the regional level, 18/76 (24%) at the hospital level and 128/1038 (12%) at the surgeon level outside the 99.9% confidence interval (CI). The estimated median odds ratios were 1.13 (95% CI 1.00-1.31) at the regional level, 1.93 (95% CI 1.70-2.19) at the hospital level and 2.38 (95% CI 2.26-2.50) at the surgeon level.Conclusion: There are significant differences between hospitals and surgeons, but little or no differences between regions. These deviations confirm the lack of standardization in regards to prescription of antibiotic prophylaxis and the need more uniform routines regarding antibiotic usage. Randomized controlled trials and large population-based studies are necessary to assess assessing the effectiveness and safety of antibiotic prophylaxis in gallstone surgery.
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| 4. |
- Persson, Jan-Gunnar
(författare)
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Current Trends in Product Development
- 2016
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Ingår i: Procedia CIRP. - : Elsevier. ; , s. 378-383
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Konferensbidrag (refereegranskat)abstract
- This paper will summarize the authors' experience over the last decades, from new methods developed and used within Product Development, as well as current trends. Hence a general and broad overview is presented, rather than recent research results. Driving forces in PD are: Technology, Market and Society. Ecological, economic and social sustainability require recycling, reuse, energy conservation and new business concepts. Customization is carried out by modular architecture, combining customer specific products with volume production of components and sub-systems. PD integrates "hard" properties (engineering), with "soft" properties (industrial design). Fundamental PD characteristics are: Iteration, Integration (technical and organizational), and Innovation. Globally distributed industrial partners co-operate using Internet. Iteration: process loops are speeded up by modeling/simulation, virtual prototyping and additive manufacturing. Structured PD: Initial specification of "what"-functional requirements, then "how"-generation of design solutions. Interdependencies analysis is important to simplify the product's structure. The V-model for specification and verification is commonly used. A 3-stage industrial process separates strategy, core technology development, and product design for market introduction.
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| 5. |
- Enochsson, Lars, et al.
(författare)
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Kvalitetsregister för gallstenskirurgi har förbättrat vården
- 2015
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 112
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Registry for cholecystectomy and endoscopic retrograde cholangiopancreatography (ERCP) (GallRiks) is a validated register with high coverage. The registry started on May 1, 2005 and serves as a base for audit on gallstone disease treatment and also provides a database for clinical research. The aim of this study is to present an overview of the clinical consequences and implementations in patient care that GallRiks research may have contributed to during a 10-year period. Results from studies on GallRiks data have reduced the use of antibiotic and thromboembolic prophylaxis as well as showed the importance of intraoperative cholangiography. Furthermore, the studies on GallRiks data have most probably changed the treatment strategies in ERCP. Studies on GallRiks data have changed and improved the management of patients in Sweden who undergo gallstone surgery or ERCP.
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| 6. |
- Olsson, Greger, et al.
(författare)
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The role of antibiotic prophylaxis in routine endoscopic retrograde cholangiopancreatography investigations as assessed prospectively in a nationwide study cohort.
- 2015
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 50:7, s. 924-931
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Risk factors for complications after endoscopic retrograde cholangiopancreatography (ERCP) with emphasis on the potential advantage of the use of prophylactic antibiotics were studied in a national population-based study cohort.MATERIALS AND METHODS: All ERCP procedures registered in the Swedish Registry of Gallstone Surgery and ERCP (GallRiks) between May 2005 and June 2013 were analyzed. Patients with ongoing antibiotic treatment, incomplete registration or those who had not undergone an index ERCP were excluded. Risk factors for adverse events were analyzed.RESULTS: Data from 47,950 ERCPs were collected, but after applying the exclusion criteria, 31,188 examinations were analyzed. In the group receiving prophylactic antibiotics, the postoperative adverse event rate was 11.6% compared with 14.2% in the group without antibiotics. The odds ratio (OR) for the risk of postoperative adverse events in patients receiving prophylactic antibiotics was 0.74 (95% confidence interval [CI]: 0.69-0.79). When analyzing a subgroup of 21,893 ERCPs for the three most common indications (common bile duct stones, malignancy, and obstructive jaundice), the beneficial effect of prophylactic antibiotics on adverse events remained (OR = 0.76; 95% CI: 0.70-0.82). Further, in the subgroup of patients with obstructive jaundice, the administration of prophylactic antibiotics had a beneficial effect on septic complications (OR = 0.76; 95% CI: 0.58-0.97).CONCLUSION: The risk of adverse events after ERCP is reduced 26% if antibiotics are given prophylactically during ERCP investigations, as suggested by data gained from this national population-based study. However, in absolute terms, the reduction in adverse events by prophylactic antibiotics is modest (2.6%).
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| 7. |
- Hamodi, Hussan
(författare)
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Reliability and Life Cycle Cost Modelling of Mining Drilling Rigs
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the context of mining, drilling is the process of making holes in the face and walls of underground mine rooms, to prepare those rooms for the subsequent operation, which is the charging process. Due to the nature of the task, drilling incurs a high number of drilling rig failures. Through a combination of a harsh environment (characterised by dust, high humidity, etc.), the operating context, and reliability and maintainability issues, drilling rigs are identified as a major contributor to unplanned downtime.The purpose of the research performed for this thesis has been to develop methods that can be used to identify the problems affecting drilling rig downtime and to identify the economic lifetime of drilling rigs. New models have been developed for calculating the optimum replacement time of drilling rigs. These models can also be used for other machines which have repairable or replaceable components. Based on an analysis performed in a case study, a life cycle cost (LCC) optimization model has been developed, taking the most important factors affecting the economic replacement time of drilling rigs into consideration. To this end, research literature studies, case studies, and simulation studies have been performed, interviews have been held, observations have been made and data have been collected. For the data analysis, theories and methodologies within reliability, maintainability, ergonomics and optimization have been combined with the best practices from the related industries.Firstly, this thesis analyses the downtime of the studied drilling rigs, with the precision and uncertainty of the estimation at a given confidence level, along with the factors influencing the failures. Secondly, the thesis identifies components that significantly contribute to the downtime and the reason for that downtime (maintainability and/or reliability problems). Based on the failure analysis, some minor suggestions have been made as to how to improve the critical components of the drilling rig. Thirdly, a new method is proposed that can help decision makers to identify the replacement time of reparable equipment from an economic point of view. Finally, the thesis proposes a method using the artificial neural network (ANN) for predicting the economic lifetime of drilling rigs through a series of basic weights and response functions. This ANN-based method can be made available to engineers without the use of complicated software.Most of the results are related to specific industrial and scientific challenges, such as planning for cost-effectiveness. The results of the case study are promising for the possibility of making a significant reduction in the LCC by optimizing the lifetime. The results have been verified through interaction with experienced practitioners from both the manufacturer and the mining company using the drilling rig in question.
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| 8. |
- Löfgren, Stefan, et al.
(författare)
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Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach
- 2014
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 186, s. 115-125
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Tidskriftsartikel (refereegranskat)abstract
- The WHAM-F-TOX model quantifies the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (F-TOX), a linear combination of the products of organism-bound cation and a toxic potency coefficient for each cation. We describe the application of the model to predict an observable ecological field variable, species richness of pelagic lake crustacean zooplankton, studied with respect to either acidification or the impacts of metals from smelters. The fitted results give toxic potencies increasing in the order H+ < Al < Cu < Zn < Ni. In general, observed species richness is lower than predicted, but in some instances agreement is close, and is rarely higher than predictions. The model predicts recovery in agreement with observations for three regions, namely Sudbury (Canada), Bohemian Forest (Czech Republic) and a subset of lakes across Norway, but fails to predict observed recovery from acidification in Adirondack lakes (USA). (C) 2013 Elsevier Ltd. All rights reserved.
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| 9. |
- Enochsson, Lars, et al.
(författare)
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The Swedish Registry of Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography (GallRiks) : A nationwide registry for quality assurance of gallstone surgery.
- 2013
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Ingår i: JAMA Surgery. - : American Medical Association (AMA). - 2168-6254 .- 2168-6262. ; 148:5, s. 471-8
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To describe the process of initiating and organizing a nationwide validated web-based quality registry of gallstone surgery and endoscopic retrograde cholangiopancreatography (ERCP) and to present some clinical data and the impact the registry has had on the clinical treatment of gallstones.DESIGN: Observational, population-based registry study.SETTING: Data from the nationwide Swedish Registry of Gallstone Surgery and ERCP (GallRiks).PATIENTS: From May 1, 2005, to December 31, 2011, 63 685 cholecystectomies (laparoscopic and open) and 37 860 ERCPs have been prospectively registered in GallRiks.INTERVENTIONS: Cholecystectomies, laparoscopic or conventional, as well as ERCP in a population-based setting.MAIN OUTCOME MEASURES: Registrations of all cholecystectomies and ERCPs are performed online by the surgeon or endoscopist. Thirty-day follow-up of both gallstone surgery and ERCP is mandatory, as is an additional 6-month follow-up of the cholecystectomies. Scores on the 36-Item Short Form Health Survey are registered preoperatively and 6 months postoperatively in elective cholecystectomies at selected units.RESULTS: The 30-day overall complication rate is 6.1% in elective cholecystectomy, 11.2% in urgent cholecystectomy, and 12.0% following ERCP. The use of antibiotic and thromboembolic prophylaxis in elective laparoscopic cholecystectomy in Sweden has decreased by 8.7% and 17.8% (2006-2011), respectively, mainly owing to presentation of GallRiks data both at meetings and published in peer-reviewed publications. The large database has also enabled several research projects, including one demonstrating that the intention to perform intraoperative cholangiography reduced the risk of death after cholecystectomy. The database has reached greater than 90% national coverage and is continuously validated.CONCLUSIONS: GallRiks is a validated national quality registry for gallstone surgery and ERCP, serving as a base for audit of gallstone disease treatment. It also provides a database for clinical research.
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