| 1. |
- Carlander, Johan, 1971-
(author)
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Energy based surgical instruments : With particular focus on collateral thermal injury
- 2015
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Doctoral thesis (other academic/artistic)abstract
- Iatrogenic post-operative nerve dysfunction is a significant problem in many areas of surgery and can be caused by collateral thermal injury from activation of energy based surgical devices (EBD).The aims of this thesis were to: create an animal model in order to compare mono- and bipolar electrosurgery (ES) and an ultrasonic dissection (UD) with regard to collateral thermal nerve injury, and with data of a national multicenter register to study the use of EBD and their potential effects on operation time and complication rates in thyroid surgery.urgical devices (EBD).Material and Methods: The biceps femoris muscle of 104 anesthetized rats was cut in a standard manner adjacent to the sciatic nerve using clinical relevant settings of mono- and bipolar ES and UD. The sciatic nerve was stimulated supramaximally and the electromyographic (EMG) potential recorded before and after each experiment. Nerve dysfunction was defined as > 10% reduction of the evoked EMG potential. In Paper II and III temperature was measured before, during and after instrument activation. The sciatic nerves were coded and examined blinded with light (LM) and electron microscopy (EM). Advanced temperature measurements were conducted in Paper II and III. In Paper IV, the use of EBD was specifically registered in the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery (SQRTPA) during one year and 1297 patients were included. Operation time, recurrent laryngeal nerve (RLN) injury, post-operative hypoparathyroidism and the use of topical haemostatic agents were compared between bipolar ES, electric vessel sealing (EVS) and UD. Clamp and Tie technique (C-A-T) being without thermal risk constituted the control group.Results: In Paper I the EMG potential was significantly more frequent reduced in the monopolar and bipolar ES group compared to the UD group and LM showed significantly less nerve damage in the UD group. In Paper II exact temperature measurements was possible with thermoelectric micros sensors and the thermal dose was significantly less and with less variation for the UD compared to the bipolar ES. Similar to the Paper I the EMG potential was significantly more frequent reduced in the ES group. Moderate and severe morphological damage was significantly less common in the UD group compared to monopolar ES. We found no statistical correlation between the highest temperatures/doses and the degree of morphological damage or functional loss. In Paper III the temperature increase was significantly less and with shorter duration in the UD group, compared to bipolar ES. LM and EM demonstrated loss of density in the myelin sheet only in a small number of nerves in all groups after instrument activation 1 mm from the nerve.In Paper IV, operation time was significantly shorter in the UD group and significantly longer in the EVS and bipolar ES group, compared to C-A-T. Postoperative hypoparathyroidism with need for Calcium treatment at discharge and at 6 weeks was significantly higher with ES instruments compared to UD. The incidence of reported RLN injury was 2.5% at 6 weeks postoperatively without statistical differences between the groups. Topical haemostatic agents were more frequently used in the EBD groups compared to C-A-T.Conclusion: The experimental Papers (I-III) demonstrated a lower risk of adverse collateral thermal nerve injury with activation of the mechanical UD technique compared to ES techniques. In the nationwide multicenter register Paper (IV), the use of UD shortened end EVS increased operation time compared to the low cost C-A-T. The UD instruments had a lower risk of hypoparathyroidism than electrosurgery.
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| 2. |
- Carlander, Johan, et al.
(author)
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Heat Production, Nerve Function, and Morphology following Nerve Close Dissection with Surgical Instruments
- 2012
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In: World Journal of Surgery. - : Springer Verlag (Germany). - 0364-2313 .- 1432-2323. ; 36:6, s. 1361-1367
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Journal article (peer-reviewed)abstract
- The aim of the present study was to compare an ultrasonically activated instrument (US), monopolar electrosurgery, and bipolar electrosurgery (ES) with respect to heat production, nerve function, and nerve morphology following in vivo application. less thanbrgreater than less thanbrgreater thanThe biceps femoris muscle of anesthetized rats was cut in a standardized manner longitudinally 1 mm adjacent to the sciatic nerve using US shears, a monopolar ES knife, or a bipolar ES scissors. Activation time and temperature were recorded continuously within 1-4 mm of the activation site ipsilateral and contralateral to the nerve with two thermoelectric microsensors. Temperature rise and time delay of reaching the temperature maximum, as an expression of heat spread within tissue, maximum temperature, and thermal dose (equivalent time of exposure at 43A degrees C) were measured and calculated. A total of 49 functional experiments were conducted. The electromyographic (EMG) potential was recorded distally. Nerve dysfunction was defined as more than 10% loss of the evoked EMG amplitude. Forty-eight nerves were coded and submitted to blind histopathological examination, and morphological damage was graded on a 4-grade scale. less thanbrgreater than less thanbrgreater thanThe maximum temperature elevation and the thermal dose were significantly higher for the bipolar ES compared with the US instrument ( = 0.024, = 0.049), and with much less variation of results for the US instrument. The monopolar ES maximum temperature and thermal dose were lower, but a very large variation occurred, probably as a result of more random electrical spread to the ground electrode and muscle motion artifacts. Functional loss was least common in the US group-without being significant-compared to bipolar and monopolar ES. Moderate and severe morphological damage was significantly less common in the US group than in the monopolar ES group ( = 0.041). We found no statistically significant correlation between the highest temperatures and the degree of morphological damage or functional loss less thanbrgreater than less thanbrgreater thanThe temperature elevation depends strongly on the distance to the activated instrument. The bipolar ES scissors generates a higher maximum temperature and thermal dose with a greater variation in than the US. Functional loss and severe morphological damage were uncommon in all groups.
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| 3. |
- Carlander, Johan, et al.
(author)
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Risk of Complications with Energy-Based Surgical Devices in Thyroid Surgery : A National Multicenter Register Study
- 2016
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In: World Journal of Surgery. - : Springer Science and Business Media LLC. - 0364-2313 .- 1432-2323. ; 40:1, s. 117-123
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Journal article (peer-reviewed)abstract
- BackgroundEnergy-based surgical devices (EBD) combining cutting and coagulation are increasingly used in thyroid surgery. However, there is a lack of information about potential benefits and risk of complications outside controlled trials. The aims of this national multicenter register study were to describe the use of EDB, their potential effect on complication rates, and on operation time.Materials and methodsThe Scandinavian Quality Register for Thyroid and Parathyroid surgery includes 35 surgical units in Sweden and covered 88 % of the thyroid procedures performed during 2008–2009. The use of the EBD was specifically registered for 12 months, and 1297 patients were included. Surgically related complications and operation time were evaluated. The clamp-and-tie group (C-A-T) constituted the control group for comparison with procedures where EBD was used.ResultsThe thyroid procedures performed included C-A-T (16.6 %), bipolar electrosurgery (ES: 56.5 %), electronic vessel sealing (EVS: 12.2 %), and ultrasonic dissection (UD: 14.5 %). Mean operative time was longer with EVS (p < 0.001) and shorter with UD (p < 0.05) than in the other groups. The bipolar ES group and the EVS group had higher incidence of calcium treatment at discharge and after 6 weeks than the UD group. No significant difference in nerve injury was found between the groups. There was a significant more frequent use of topical hemostatic agents in the EBD group compared to C-A-T.ConclusionIn this national multicenter study, the use of UD shortened and EVS increased operating time. There was a higher risk of calcium treatment at discharge and after 6 weeks after use of EVS and bipolar ES than after UD use. There was a significant more frequent use of topical hemostatic agents in the EBD groups compared to C-A-T.
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| 4. |
- Carlander, Johan, et al.
(author)
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Risk of nerve injury after use of energy based surgical devices
- 2015
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Other publication (other academic/artistic)abstract
- BackgroundThe use of energy based surgical devices (EBD) is well established in surgery. Iatrogenic nerve injury is a common problem in many areas of surgery and may be caused by collateral thermal injury from EBD.MethodsThe sciatic nerve of anaesthetized rats was used in an experimental model. A bipolar scissors (ES) was compared to an ultrasonic device (UD) by cutting the femoris muscle longitudinal during 3 seconds at 1 mm from the sciatic nerve. Temperature and electromyography (EMG) were recorded before, during and after activation of the devices. The nerves were examined blinded with light (LM) and electronic microscope (EM).ResultsThe temperature increase was significantly less and with shorter duration after instrument activationfor the UD compared to bipolar ES. The EMG potential was reduced by 3 % in the UD group and 6% in the ES group respectively (n.s.). LM and EM demonstrated a loss of density in the myelin sheath in a small number of nerves in both groups.ConclusionThis study indicates less thermal spread in tissue following activation of the ultrasonic devices compared to bipolar ES. EMG and morphology assessment with LM and EM indicate a small risk and probably reversible thermal injury after clinical relevant instrument activation at 1 mm from the nerve.
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| 5. |
- Carlson, Johan, et al.
(author)
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Frequency and temperature dependence of acoustic properties of polymers used in pulse-echo systems
- 2003
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In: Proceedings, 2003 IEEE Ultrasonics Symposium. - Piscataway, NJ : IEEE Communications Society. - 0780379225 ; , s. 885-888
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Conference paper (peer-reviewed)abstract
- In ultrasonic pulse-echo systems, polymers like PMMA (polymethylmethacrylate) and PEEK (polyetheretherketone) are often used as buffer-rods, placed between the ultrasound transducer and the unknown material (liquid, gas, or solid material). Provided the acoustic properties of the buffer-rods are known, it is possible to calculate these also for the unknown material, based on reflections between the buffer-rod and the unknown medium. However, temperature changes also affect these properties. In this paper we present a method for measuring acoustic attenuation, speed of sound and density, for buffer-rod materials. We also give experimental values for PMMA and PEEK, for temperatures between 5/spl deg/C and 37/spl deg/C, and for 5 MHz and 10 MHz ultrasound frequency.
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| 6. |
- Currie, Andrew, et al.
(author)
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The Impact of Enhanced Recovery Protocol Compliance on Elective Colorectal Cancer Resection Results From an International Registry
- 2015
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In: Annals of Surgery. - : Lippincott Williams & Wilkins. - 0003-4932 .- 1528-1140. ; 261:6, s. 1153-1159
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Journal article (peer-reviewed)abstract
- Background: The ERAS (enhanced recovery after surgery) care has been shown in randomized clinical trials to improve outcome after colorectal surgery compared to traditional care. The impact of different levels of compliance and specific elements, particularly out with a trial setting, is poorly understood.Objective: This study evaluated the individual impact of specific patient factors and perioperative enhanced recovery protocol compliance on postoperative outcome after elective primary colorectal cancer resection.Methods: The international, multicenter ERAS registry data, collected between November 2008 and March 2013, was reviewed. Patient demographics, disease characteristics, and perioperative ERAS protocol compliance were assessed. Linear regression was undertaken for primary admission duration and logistic regression for the development of any postoperative complication.Findings: A total of 1509 colonic and 843 rectal resections were undertaken in 13 centers from 6 countries. Median length of stay for colorectal resections was 6 days, with readmissions in 216 (9.2%), complications in 948 (40%), and reoperation in 167 (7.1%) of 2352 patients. Laparoscopic surgery was associated with reduced complications [odds ratio (OR) = 0.68; P < 0.001] and length of stay (OR = 0.83, P < 0.001). Increasing ERAS compliance was correlated with fewer complications (OR = 0.69, P < 0.001) and shorter primary hospital admission (OR = 0.88, P < 0.001). Shorter hospital stay was associated with preoperative carbohydrate and fluid loading (OR = 0.89, P = 0.001), and totally intravenous anesthesia (OR= 0.86, P < 0.001); longer stay was associated with intraoperative epidural analgesia (OR = 1.07, P = 0.019). Reduced postoperative complications were associated with restrictive perioperative intravenous fluids (OR = 0.35, P < 0.001).Conclusions: This analysis has demonstrated that in a large, international cohort of patients, increasing compliance with an ERAS program and the use of laparoscopic surgery independently improve outcome.
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| 7. |
- Elvstam, Olof, et al.
(author)
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Associations between HIV viremia during antiretroviral therapy and cardiovascular disease
- 2022
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In: AIDS (London, England). - 1473-5571. ; 36:13, s. 1829-1834
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To investigate the association between HIV viremia exposure during antiretroviral therapy (ART) and cardiovascular disease (CVD) risk.DESIGN: Nationwide observational cohort.METHODS: Participants (age > 15 years) from the Swedish nationwide InfCareHIV register initiating ART 1996-2017 were categorized in a time-updated manner into four viremia categories, starting from 12 months after ART initiation: suppression (<50 copies/ml), low-level viremia (50-199 copies/ml and 200-999 copies/ml, respectively), and high-level viremia (≥1000 copies/ml). In addition, cumulative viremia was estimated as the area under the log viral load (VL) curve. Proportional subhazard models adjusted for sex, age, pre-ART CD4 and VL, injection drug use, and country of birth were used to analyze the association between viremia exposure and CVD risk (ischemic heart disease, stroke, and heart failure; data obtained by linkage to national registers), accounting for the competing risk of non-CVD death.RESULTS: In all, 337 cases of CVD were observed during 44 937 person-years of follow-up (n = 6562). Higher viremia exposure was associated with CVD, both when parameterized as cumulative viremia (adjusted subhazard ratio [aSHR] per 1 log10 copy × year/ml, 1.03; 95% confidence interval [CI], 1.01-1.05) and as viremia category (aSHR for high-level viremia versus suppression, 1.45; 95% CI, 1.03-2.05). We observed no association between CVD and low-level viremia compared with those with suppression.CONCLUSIONS: Higher exposure to HIV viremia was linked to CVD in ART recipients, whereas no increased risk was detected for people with low-level viremia compared with viral suppression. Causal inference is limited by the observational nature of this study.
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| 8. |
- Holm, Maja, et al.
(author)
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Delivering and participating in a psycho-educational intervention for family caregivers during palliative home care: a qualitative study from the perspectives of health professionals and family caregivers
- 2015
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In: Bmc Palliative Care. - : Springer Science and Business Media LLC. - 1472-684X. ; 14
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Journal article (peer-reviewed)abstract
- Background: Family caregivers in palliative care have a need for knowledge and support from health professionals, resulting in the need for educational and supportive interventions. However, research has mainly focused on the experiences of family caregivers taking part in interventions. To gain an increased understanding of complex interventions, it is necessary to integrate the perspectives of health professionals and family caregivers. Hence, the aim of this study is to explore the perspectives of health professionals and family caregivers of delivering and participating in a psycho-educational intervention in palliative home care. Methods: A psycho-educational intervention was designed for family caregivers based on a theoretical framework describing family caregiver's need for knowing, being and doing. The intervention was delivered over three sessions, each of which included a presentation by healthcare professionals from an intervention manual. An interpretive descriptive design was chosen and data were collected through focus group discussions with health professionals and individual interviews with family caregivers. Data were analysed using framework analysis. Results: From the perspectives of both health professionals and family caregivers, the delivering and participating in the intervention was a positive experience. Although the content was not always adjusted to the family caregivers' individual situation, it was perceived as valuable. Consistently, the intervention was regarded as something that could make family caregivers better prepared for caregiving. Health professionals found that the work with the intervention demanded time and engagement from them and that the manual needed to be adjusted to suit group characteristics, but the experience of delivering the intervention was still something that gave them satisfaction and contributed to them finding insights into their work. Conclusions: The theoretical framework used in this study seems appropriate to use for the design of interventions to support family caregivers. In the perspectives of health professionals and family caregivers, the psycho-educational intervention had important benefits and there was congruence between the two groups in that it provided reward and support. In order for health professionals to carry out psycho-educational interventions, they may be in need of support and supervision as well as securing appropriate time and resources in their everyday work.
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| 9. |
- Holm, Maja, et al.
(author)
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Short- and Long Term Effects of a Randomised Psycho-educational Intervention for Family Caregivers in Specialised Palliative Home Care
- 2015
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In: 14th World Congress of European Association of Palliative Care. 8-10 May 2015 Copenhagen, Denmark..
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Conference paper (other academic/artistic)abstract
- Background: Family caregivers in palliative home care often face a heavy responsibility and a burden of caring for a person with incurable illness. Research has showed that there is a need for intervention studies to make family caregivers more prepared and competent for their situation. Aim: To investigate the short- and long-term effects of a randomised psycho-educational intervention for family caregivers in specialised palliative home care. Methods: A psycho-educational intervention with supportive and educative components was designed based on the theoretical framework of Andershed and Ternestedt. Family caregivers from 10 specialised palliative home care units were included. The intervention was delivered as a randomised control trial where family caregivers who agreed to take part in the study were randomised to an intervention group with three sessions or to a control group with standard support. Family caregivers were required to answer to questionnaires at baseline, upon completion and two months following the intervention. The questionnaires comprised instruments concerning family caregivers’ feelings of preparedness, competence, reward, burden, health, anxiety and depression. A regression model based on robust variance estimates was conducted for all tested outcomes. Results: 177 family caregivers completed all three measurements. Results showed that in the short-term follow-up, family caregivers in the intervention group had significantly better self-rated competence for caregiving and experience of health. In the long-term follow-up, the intervention group had significantly better self-rated preparedness for caregiving compared to the control group. Conclusion: The results add to previous research that relatively short psycho-educational interventions could have important positive short- and long-term effects on family caregivers in palliative care.
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