| 1. |
- Magnusson, Patrik K. E., et al.
(author)
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The Swedish Twin Registry : establishment of a biobank and other recent developments
- 2013
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In: Twin Research and Human Genetics. - Cambridge, United Kingdom : Cambridge University Press. - 1832-4274 .- 1839-2628. ; 16:1, s. 317-329
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Journal article (peer-reviewed)abstract
- The Swedish Twin Registry (STR) today contains more than 194,000 twins and more than 75,000 pairs have zygosity determined by an intra-pair similarity algorithm, DNA, or by being of opposite sex. Of these, approximately 20,000, 25,000, and 30,000 pairs are monozygotic, same-sex dizygotic, and opposite-sex dizygotic pairs, respectively. Since its establishment in the late 1950s, the STR has been an important epidemiological resource for the study of genetic and environmental influences on a multitude of traits, behaviors, and diseases. Following large investments in the collection of biological specimens in the past 10 years we have now established a Swedish twin biobank with DNA from 45,000 twins and blood serum from 15,000 twins, which effectively has also transformed the registry into a powerful resource for molecular studies. We here describe the main projects within which the new collections of both biological samples as well as phenotypic measures have been collected. Coverage by year of birth, zygosity determination, ethnic heterogeneity, and influences of in vitro fertilization are also described.
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| 2. |
- Hahn, S., et al.
(author)
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Contact-Less Electrical Defect Characterization of Semi-Insulating 6H-SiC Bulk Material
- 2009
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In: Materials Science Forum Vols. 600-603. - : Trans Tech Publications. ; , s. 405-408
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Conference paper (peer-reviewed)abstract
- The novel technique microwave detected photo induced current transient spectroscopy (MD-PICTS) was applied to semi-insulating 6H-SiC in order to investigate the properties of inherent defect levels. Defect spectra can be obtained in the similar way to conventional PICTS and DLTS. However, there is no need for contacting the samples, which allows for non-destructive and spatially resolved electrical characterization. This work is focused on the investigation of semi-insulating 6H-SiC grown under different C/Si-ratios. In the corresponding MD-PICTS spectra several shallow defect levels appear in the low temperature range. However the peak assignment needs further investigation. Additionally different trap reemission dynamics are obtained for higher temperatures, which are supposed to be due to different compensation effects.
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| 3. |
- Magnusson, Niklas, 1975-
(author)
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Postoperative aspects of inguinal hernia surgery : pain and recurrences
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Approximately one in four men will have surgery for ingunial hernia in their lifetime. In Sweden, 16 000 procedures are performed each year. To investigate the possible link between handling of nerves and sensory disturbance, 97 groins in 92 patients were examined one year after inguinal hernia surgery. Sensory disturbances were found to be common after open surgery (29 %), but were not seen after the laparoscopic procedures. No significant relationship between sensory disturbance and handling of nerves or pain was seen. The risk for recurrence has been significantly reduced due to the use of prosthetic meshes, but continued surveillance of this important outcome will always be necessary. In that context, the time frame in which recurrence develops in relation to possible risk factors can help our understanding of the underlying mechanisms. To explore such temporal relationships, 142,578 patients were included in a register study. A relative over-risk for early recurrence was seen after suture repair, laparoscopic repair, after postoperative complications, and after surgery for previous recurrence. Corticosteroids are known to decrease pain and nausea after several surgical procedures. In a randomised trial on open hernia surgery, 398 patients were randomised to treatment with 12 mg of betamethasone or placebo. Decreased levels of pain were seen on the day of surgery, the next day and after one month. No difference was seen on days 2-7 and after one year. Nausea was not common and did not differ between the groups. Reoperation is sometimes performed to correct a presumed structural defect thought to cause the long-term pain. In order to evaluate the result of such treatment, 111 cases were analysed based on register data, questionnaires and medical records. Sixty-two per-cent of the patients reported an improvement compared to before the reoperation, but a high level of pain remaining (42 %), and impaired quality of life was seen. There was no clear advantage for any surgical intervention over the other.
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| 4. |
- Magnusson, Niklas, 1975-, et al.
(author)
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Reoperation for chronic pain after groin hernia surgery : a population-based study
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Other publication (other academic/artistic)abstract
- Introduction:Evidence supporting any one technique used at reoperation for chronic pain after hernia surgery is lacking.Materials and methods:All patients who had undergone surgery for chronic pain after previous groin hernia surgery 1999-2006 were identified in the Swedish Hernia Register (n=237). Data on the surgical technique used were abstracted from the medical records. The patients were asked to answer a set of questions including SF-36, the Inguinal Pain Questionnaire (IPQ) and other questions in order to evaluate the prevalence of pain after reoperation.Results:The study group consisted of 95 males and 16 females, mean age 53 years. Continued pain after reoperation was present in 19 %. In 27 % of cases an intervention aimed at suspected ilioinguinal neuralgia was performed. The mesh was removed completely in 28 % and partially in 13 %. A suture at the pubic tubercle was removed in 13 % of cases.Decrease in pain after the most recent reoperation was reported by 69 patients (62%), no change in pain by 21 patients (19%) and increase in pain in 21 patients (19%). There was no significant difference in outcome between the techniques applied.Conclusion:Patients reoperated for chronic pain after hernia surgery often report a reduction in pain, but the natural course of chronic pain and selection of patients makes it difficult to draw any definite conclusions.
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| 5. |
- Magnusson, Niklas, 1975-, et al.
(author)
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Reoperation for persistent pain after groin hernia surgery : a population-based study
- 2015
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In: Hernia. - : Springer. - 1265-4906 .- 1248-9204. ; 19:1, s. 45-51
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Journal article (peer-reviewed)abstract
- Purpose: The aim of the present study was to assess the outcome results after reoperation for persistent pain after hernia surgery in a population-based setting.Methods: All patients who had undergone surgery for persistent pain after previous groin hernia surgery 1999-2006 were identified in the Swedish Hernia Register (n = 237). Data on the surgical technique used were abstracted from the medical records. The patients were asked to answer a set of questions including SF-36 to evaluate the prevalence of pain after reoperation.Results: The study group consisted of 95 males and 16 females, mean age 53 years. In 27 % of cases an intervention aimed at suspected ilioinguinal neuralgia was performed. The mesh was removed completely in 28 % and partially in 13 %. A suture at the pubic tubercle was removed in 13 % of cases. Decrease in pain after the most recent reoperation was reported by 69 patients (62 %), no change in pain by 21 patients (19 %) and increase in pain in 21 patients (19 %). There was no significant difference in outcome between mesh removal, removal of sutures at the tubercle or interventions aimed at the ilioinguinal nerve. All subscales of SF-36 were significantly reduced when compared to the age-and gender-matched general population (p < 0.05).Conclusions: Patients reoperated for persistent pain after hernia surgery often report a reduction in pain, but the natural course of persistent pain, the relatively low response rate and selection of patients make it difficult to draw definite conclusions.
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| 6. |
- Magnusson, Niklas, 1975-, et al.
(author)
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Sensory disturbances and neuropathic pain after inguinal hernia surgery
- 2010
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In: Scandinavian Journal of Pain. - : Walter de Gruyter GmbH. - 1877-8860 .- 1877-8879. ; 1:2, s. 108-111
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Journal article (peer-reviewed)abstract
- Objectives: The aim of this study was to explore how the handling of nerves affects the risk for developing sensory disturbances (SDs) following groin hernia surgery.Patients and methods: All patients 18 years or older undergoing surgery for inguinal hernia at Mora Hospital, Sweden, during an eight-month period in 2006, were eligible for inclusion. The surgical procedure was recorded prospectively according to a standardised protocol. One year postoperatively all patients were requested to answer the Inguinal Pain Questionnaire as well as a set of 18 sensory and affective pain descriptors. They were also invited to clinical examination including sensory testing.Results: Of the 157 hernia repairs in Mora during the period of study, 128 repairs in 116 patients, were registered prospectively according to the study protocol. Laparoscopic total extraperitoneal (TEP) repair was performed in 36 (28%) of the patients. Ninety-two (79%) patients, including five patients operated bilaterally, underwent postoperative examination. SDs were found in 33 (34%) of the groins examined. No descriptor was found that significantly predicted the presence of altered examination findings. No significant association between the intraoperative handling of nerves and SD was seen. In the TEP-group, no SDs were seen. Infiltration of local anaesthetic agents and blockade of the ilioinguinal nerve prior to surgery were found to be significantly associated with SD more than 2 cm away from the car (both p< 0.05). The presence of SD was not associated with significant pain.Conclusions: SDs are common after open hernia surgery, but are not associated with persistent postoperative pain.
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| 7. |
- Magnusson, Niklas, 1975-, et al.
(author)
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The time profile of groin hernia recurrences
- 2010
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In: Hernia. - : Springer. - 1265-4906 .- 1248-9204. ; 14:4, s. 341-344
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Journal article (peer-reviewed)abstract
- PURPOSE: If the pathogeneses of the development of a recurrence varies following the different methods of hernia repair, the time required to develop a recurrence could be expected to vary. The aim of the study was to identify risk factors affecting the time interval between the primary repair and the reoperation.METHODS: Data from the Swedish Hernia Register were used. Each year of the 5-year follow-up period was treated as a separate subgroup and merged together into one large group. For each risk factor, we performed a Cox proportional hazard analysis, testing for interactions between the year and the risk factor, with reoperation as the endpoint.RESULTS: Altogether, 142,578 repairs were recorded, of which 7.7% were performed on women. The mean age of the cohort was 59 years. The overall recurrence rate in the 5-year period was 4.3%. Multivariate analysis showed that recurrence following surgery for recurrent hernia occurred relatively early (P < 0.05).Recurrence also appeared early if postoperative complications were registered (P < 0.05). Recurrence after suture repair or laparoscopic repair appeared relatively early compared to recurrence following open mesh repair (P < 0.05). In a separate analysis, a relatively higher risk for early recurrence was seen for all sutured repairs compared to all mesh repairs (P < 0.05).CONCLUSIONS: The pathogenesis behind the development of recurrence probably differs depending on the technique applied during the hernia repair. The higher proportion of early recurrences following laparoscopic repair, suture repair and recurrent repair may be explained by the high proportion of technical failures.
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| 8. |
- Simsa, Jaromir, et al.
(author)
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Betamethasone in hernia surgery : a randomized controlled trial
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Other publication (other academic/artistic)abstract
- Background: postoperative pain and nausea may be a problem in day-case surgery. This study aims to investigate the effect of betamethasone on pain and nausea in inguinal hernia surgery.Methods: patients aged 18-70 years scheduled for open inguinal hernia surgery at two Swedish hospitals, March 2005-December 2009, were eligible for inclusion. Patients were randomised, to either treatment with 12 mg betamethasone intravenously, or placebo. Postoperative pain was assessed using a VAS scale on the recovery ward, each day the first postoperative week and at 1 month after surgery. One year after surgery residual pain was estimated by the Inguinal Pain Questionnaire.Results: a total of 398 patients were included (21 women, 377 men).Pain at rest (p<0.05) on the day of surgery was significantly lower in the treatment group. The pain was also significantly lower in the treatment group the day after surgery (p=0.035), but not during the remaining part of the first postoperative week. Bleeding complications were reported by 17 patients (8.5%) in the Betamethasone group and 7 (3.5%) in the placebo group (p=0.028).One month after surgery, 21/173 (12%) in the betamethasone group still had pain, compared to 33/159 (21%) in the placebo arm (p=0.049). After one year, no significant difference in pain was seen.Conclusion: 12 mg betamethasone reduced pain during the first 24 hours and at 1 month after inguinal hernia surgery. If combined with diclofenac, however, this dose may increase the risk for bleeding complications.
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