| 1. |
- Djavani Gidlund, Khatereh
(författare)
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Intra-abdominal Hypertension and Colonic Hypoperfusion after Abdominal Aortic Aneurysm Repair
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colonic ischaemia (CI), Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are devastating complications after abdominal aortic aneurysm (AAA) surgery. The aims of this thesis were to study the incidence and clinical consequences of IAH/ACS and the association between CI and intra-abdominal pressure (IAP) among patients undergoing OR for ruptured AAA (rAAA), to compare extraluminal pHi monitoring, with standard intra-luminal monitoring among patients operated on for AAA, and to study the frequency and clinical consequences of IAH/ACS after endovascular repair (EVAR) for rAAA. The incidence of ACS was 26% in a retrospective study of 27 patients undergoing OR for rAAA. Consensus definitions on IAH/ACS were appropriate for patients after OR for rAAA: 78% (7/9) of patients with IAH grade III or IV developed organ failure and all patients who developed CI had some degree of IAH. Active fluid resuscitation treating hypovolaemia to avoid CI may partly cause IAH. The association between CI and IAP was investigated in a prospective study on 29 patients operated on for rAAA, 86% (25/29) were treated for hypovolaemia and ten (34%) had both IAH and CI. Since monitoring colonic perfusion is very important and there is no ideal method, a new technique, extraluminal colonic tonometry to detect colonic perfusion was compared with standard intraluminal tonometry. Although, this new method was not able to determine the severity of ischaemia it may serve as a screening test. EVAR of rAAA is feasible and patients may benefit from this less invasive procedure. Of 29 patients treated with this technique, 10% developed ACS, and all patients except one with preoperative shock developed some degree of IAH. In conclusion, IAP/ACS is common after both OR and EVAR for rAAA, and is associated with adverse outcome. Monitoring IAP and colonic perfusion with timely intervention may improve outcome.
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| 2. |
- Avallin, Therese, 1982-
(författare)
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Achieving person-centred pain management for the patient with acute abdominal pain : Guided by the Fundamentals of Care framework
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis is to explore how to achieve and measure person-centred pain management (PCPM) for the patient with acute abdominal pain (AAP) in acute surgical care. The Fundamentals of Care (FoC) framework guides all studies.The methods: In Study I, focused ethnography is used with 92h of participant observations (n=34) at the emergency department (n=1) and surgical wards (n=2), including 261 patient–provider interactions. In Study II, case study is used for secondary analysis of 20 observations from Study I. In Study III, a questionnaire is developed in a systematic process to measure PCPM, performed by combining; a validated questionnaire, theoretical and empirical evidence. The questionnaire is tested by question appraisal, theoretical experts (n=2), patients (n=5) and providers (n=5), and thereafter by patients (n=100) at surgical wards (n=4). In Study IV, a qualitative systematic review is performed with a synthesis by thematic analysis, to test and refine a model for PCPM from Study I. The synthesis includes 15 qualitative studies representing patients (n=495) and/or nurses (n=259) from n= 3 emergency departments and n=17 hospital wards in n=9 countries. The patients are ≥ 18 years old, with AAP (Studies I-IV), or acute pain from surgery (Study IV). The results confirms that the patient still suffer from unmanaged pain in acute surgical care, and presents actions on behalf of the patient and provider, and contextual factors including the organizational culture, to achieve and measure PCPM. The studies presents a model for PCPM from the patient perspective (Study I), patient-provider communications contributing to meeting fundamental care needs (Study II), an initially feasible and valid questionnaire to measure PCPM (Study III), and a tested and refined model for PCPM from the patient and nurse perspective (Study IV). Conclusion: This thesis presents scientific evidence providing an in-depth understanding of what is important for successful pain management from the patient’s and nurses’ perspectives, how these parts are interconnected, and how they can be achieved and measured. The results also show the feasible role of communication in meeting the patient’s fundamental care needs. This evidence is suggested to be tested and evaluated in clinical practice to perform PCPM, relieving the patient from pain.
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| 3. |
- Bernhoff, Karin, 1972-
(författare)
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Orthopaedic Patients with Lower Limb Vascular Injuries
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Vascular injuries in lower limbs are rare but serious events. If not detected and managed correctly and timely they can lead to permanent functional impairment and even limb loss. The increasing number of orthopaedic interventions, worldwide, makes awareness of this problem among orthopaedic surgeons important.The overall aim of this thesis was to describe lower limb orthopaedic injuries with associated concomitant arterial injuries, especially to the popliteal artery. Epidemiology, mechanisms of injury, management, outcomes and the patient perspective were all addressed. The research questions were generated from clinical praxis. Vascular injuries are rare events, but by using as the National Patient (NPR) and National Vascular registries (Swedvasc) a relatively speaking large cohort was studied. Deep interviews with qualitative study method were used to investigate the patients’ perspective.In papers I and II iatrogenic popliteal artery injuries (PAI) in knee-replacements, and in non-knee-replacements, were investigated. The number of knee arthroplasties in Sweden increased 1987-2008, but not the frequency of iatrogenic PAI. The most common mechanism of injury was sharp, directly to the artery. One third of the injuries resulted in pseudo-aneurysms. This was an unexpected and important finding, since these patients were often diagnosed late, resulting in poor outcome.Paper III. The interviewed patients narrated substantial functional, cosmetic and psychological impairments,4-17 years after their accidents, yet they described their lives as “normal”. Patients with saved limbs reported a need for better interpersonal support in their rehabilitation and adaptation back to “normal” life.Paper IV. Popliteal artery injury is feared in knee dislocations and fractures. The proportion incidence of vascular injury was previously reported to be 2-60%. In this large population-based study, the incidence proportion in knee dislocations was 3.4-8.2%, depending on the definition of dislocation/ligamentous injury. In knee fractures the incidence proportion was lower, only 0.2%. The dominating cause of arterial injury in knee dislocations was fall, in knee fractures it was motor vehicle accidents. Amputation- free survival after arterial injury was inferior in knee fractures compared with knee dislocations.In conclusion, PAI is a serious injury but on sequences can be limited by awareness and timely action.
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| 4. |
- Block, Tomas, 1976-
(författare)
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Acute Occlusion of the Superior Mesenteric Artery : Diagnosis and treatment
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Acute occlusion of the superior mesenteric artery (SMA) is a condition associated with high mortality and morbidity. The aim of this thesis is to evaluate diagnostic and therapeutic approaches for acute SMA occlusion. In a prospective study of patients with suspected intestinal ischemia, no biomarker was sufficiently accurate to detect this condition. In a second retrospective study, pancreatic amylase and troponin-I were elevated in a substantial proportion of patients with verified SMA occlusion. In an experimental animal model of acute SMA occlusion, microarray studies of ischemic small bowel wall were used to characterize the mRNA response to ischemia. Thrombospondin, Monocyte Chemoattractant Protein 1 and Gap Junction Alpha 1 were consistently up-regulated in all pigs with intestinal ischemia. Genes encoding previously proposed biomarkers for intestinal ischemia were either up-regulated, such as lactate dehydrogenase and creatine kinase, or down-regulated, such as intestinal fatty acid binding protein and glutathione S-transferase. In a study of the role of computed tomography in the diagnosis of SMA occlusion, it was shown that computed tomography with intravenous contrast was associated with improved survival. A retrospective analysis of all acute SMA revascularizations in Sweden 1999-2006 revealed that D-dimer was elevated in all 35 measured cases. Endovascular surgery was associated with better outcome than open surgery, both in short and in long term. The presence of postoperative short bowel syndrome was a strong independent risk-factor for decreased long-term survival. Conclusions: Data affirm that D-dimer may serve as an exclusion test for acute SMA occlusion, whereas elevated troponin-I and pancreatic amylase are potential diagnostic pitfalls. Contrast-enhanced computed tomography of the visceral arteries seems to be the best diagnostic method. Endovascular surgery is an option to open surgery in selected cases, and was associated with favourable outcome.
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| 5. |
- Cervin, Anne, 1971-
(författare)
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Popliteal Artery Aneurysms : - epidemiology, treatment and results
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Popliteal aneurysms (PA) are limb threatening, since the aneurysm thrombose and emboli from the aneurysm sac occlude the distal vessels, resulting in chronic or acute limb ischaemia. Open surgical repair (OSR) has been challenged by endovascular repair (ER), a minimal invasive technique. Little is known of long-term result, and comparisons of the methods have been difficult, since patients chosen for ER are mainly asymptomatic and have better outflow.The overall aim of this thesis was to study epidemiology and risk factors to optimize patient selection and techniques for surgical treatment of PA.Papers I and II: Data on all patients treated 2008-2012 (592 PAs in 499 patients) were analysed in the Swedish Vascular registry, Swedvasc. Patency was inferior after ER, in particular for patients with acute ischaemia. Nested in this cohort, a case-control study was performed, and the legs treated by ER (77) were matched, by indication, with twice the number treated with OSR (154). Medical records and radiologic images were collected and examined in a core-lab. In this matched cohort, the only independent risk factors for occlusion were ER and poor outflow. In a sub-group analysis of ER, risk factors for occlusion were acute ischaemia, poor out-flow, smaller stent graft diameter and elongation.Paper III: Prevalence of PA was studied in men, screened for abdominal aortic aneurysm (AAA) and of sub aneurysmal aorta, 25-29 mm. Prevalence of PA was high, 14.2%, and correlated with dilatation of the iliac arteries.Paper IV: Operations for ruptured PA (rPA) were identified in Swedvasc 1987-2012, medical records were reviewed. Compared with patients treated for other indications, they were 8 years older, had twice as large aneurysms (mean 64 mm) and many were treated with anticoagulants. The initial clinical picture was misleading.In conclusion, when treating PA the preferred surgical technique is OSR with a vein graft. Anatomical features of the popliteal artery and outflow vessels affect outcome. These findings are important for future surgical decision making.
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| 6. |
- De Basso, Rachel
(författare)
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Influence of genetics and mechanical properties on large arteries in man
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Arterial pathology is the major contributor to cardiovascular diseases and mortality. The mechanical properties of arteries are independent factors for cardiovascular disease and mortality, where genetics influence the structure of the arterial wall, which may result in change in arterial stiffness. The aims of this thesis were to study the mechanical properties of the popliteal artery (PA) in healthy subjects and the influence of angiotensin-converting enzyme (ACE) polymorphism and Fibrillin-1 (FBN1) polymorphism on large arteries. Further, the impact of FBN1 polymorphism on cardiovascular morbidity and mortality was investigated.The PA is, after the abdominal aorta, the most common site of aneurysmal development. The PA was studied in healthy subject with ultrasound and the diameter increased and the distensibility decreased with age, with men having lower distensibility than women. This seems not to be the behavior of a true muscular artery but rather of a central elastic artery such as the aorta, and might have implications for the susceptibility to aneurysm formation, as well as the association of dilating disease between the PA and the aorta. The wall stress in the PA was low and unaffected by age, probably caused by a compensatory remodeling response with an increase in wall thickness. This indicates that other mechanisms than wall stress contribute to the process of pathological dilatation in the PA.The ACE D allele may be associated with abdominal aortic aneurysm. Elderly men with the ACE D allele were associated with increased abdominal aortic stiffness compared to men carrying the I/I genotype. This suggests that the ACE D allele impairs arterial wall integrity, and in combination with local hemodynamic and other genetic factors it may have a roll in aneurysm formation.The FBN1 2/3 genotype has been associated with increased systolic blood pressure. The FBN1 2/3 genotype in middle-aged men was associated with increased abdominal aortic stiffness and blood pressure which indicates an increased risk for developing cardiovascular disease. The increased presence of plaque in the carotid artery of middle-aged men with the FBN1 2/3 genotype indicates a pathological arterial wall remodeling with a more pronounced atherosclerotic burden, but did however not affect the risk of cardiovascular events and/or death in this population. This relationship needs to be studied further.
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| 7. |
- Linder, Fredrik, 1977-
(författare)
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Trauma - Diagnostics and Triage
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Trauma is a leading cause of death worldwide and it reduces years of productive life and leads to disability. Effective trauma care relies on triage, which aims to ration the use of fine resources to patients with the greatest needs. Imaging is essential in the severely injured patient, but comes at a cost of radiation exposure, which could cause cancer in up to 1/1000 patients examined with whole body computed tomography.Paper I showed that routine whole-body CT of high-energy trauma patients may lead to excessive radiation exposure without clinical benefit. There were no missed injuries in the low risk group and the mean injury severity score (ISS) was 0.84 in this group (standard deviation SD 1.57). Paper II surveyed radiologists at 93 Nordic and 10 non-Nordic hospitals with 23 questions on usage of whole body CT in trauma. The response rate was 62% and there were several differences in criteria, protocols and radiation dose. Most, 89% consider there is a need for national/international guidelines. Paper III evaluated compliance with trauma alert criteria with the aim to describe how resources may be optimized with sustained low undertriage. The compliance with full trauma alert and no trauma alert was 80% and 79% respectively. Compliance with limited trauma alert was only 54%, and prehospital immobilization was an independent risk factor for mistriage with an odds ratio of 1.78 (95% CI 1.42 - 2.23). Paper IV demonstrated that the newly implemented Swedish trauma team activation (TTA) criteria result in a reduction in limited TTA frequency, indicating an increased efficiency in use of resources. The over- and undertriage is unchanged compared to former criteria, thus upholding patient safety.In conclusion, whole body CT in trauma should be used only in patients with clinical findings. The routines for use of whole body CT in trauma differ between institutions, and efforts to establish common guidelines are requested. Better compliance with alert criteria may optimize resource allocation, and the newly implemented national TTA criteria in Sweden are safe and resource efficient.
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| 8. |
- Mani, Kevin, 1975-
(författare)
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Abdominal Aortic Aneurysm : Epidemiological and Health Economic Aspects
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Abdominal aortic aneurysm (AAA) is a common disease that is life threatening when rupture occurs. The aims of this thesis were to study (I) the long-term survival after AAA repair, (II) the cost of repair with open (OR) and endovascular (EVAR) technique, (III) the effect of different statistical methods on interpretation of cost data, (IV) the prevalence of the disease among patients with suspected arterial disease referred to the vascular laboratory, and (V) the cost-effectiveness of selective high-risk screening. Analyses of data from the Swedish vascular registry (Swedvasc), local patient registries, patient records and hospital cost registries form the basis of this thesis. Short- and long-term survival after intact AAA repair improved over the past two decades, despite increasing patient age and rate of comorbidities over time. Compared to a general population adjusted for age, sex and calendar year, the relative 5-year survival was 90% among those surviving repair. While short-term survival improved over time after ruptured repair, relative long-term survival was stable. Despite differences in patient selection and cost structure, the total cost of AAA repair with EVAR and OR was similar in a population based setting (€28,193). There was lack of consistency in the methods used in cost-analysis in the current literature, and p-values were highly dependent on test method. The practice of selective (non-population-based) screening for AAA among patients referred to the vascular laboratory was studied. The prevalence of AAA was 4.2% among male and 1.5% among female patients. AAA was associated with high age and prevalence of arterial stenosis. Of AAAs detected through selective screening, 21.5% had undergone elective repair at 7.5 years follow-up. In a health-economic evaluation, the incremental cost-effectiveness ratio of selective screening was €11,084 per life year gained. In conclusion, survival after intact AAA repair has improved over time, despite changes in case-mix. Results of health economic reports on cost of AAA repair can be highly dependent on patient selection as well as presentation of data and the statistical methods used. Selective screening for AAA among patients referred to the vascular laboratory is cost-effective.
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| 9. |
- Rudström, Håkan, 1966-
(författare)
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Iatrogenic Vascular Injuries
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Iatrogenic vascular injuries (IVIs) and injuries associated with vascular surgery can cause severe morbidity and death. The aims of this thesis were to study those injuries in the Swedish vascular registry (Swedvasc), the Swedish medical injury insurance where insurance claims are registered, the Population and Cause of death registries, and in patient records, in order to explore preventive strategies.Among 87 IVIs during varicose vein surgery 43 were venous, mostly causing bleeding in the groin. Among 44 arterial injuries, only 1/3 were detected intraoperatively. Accidental arterial stripping predominated, with poor outcome. Four patients died, all after venous injuries.IVIs increased over time, and constitute more than half of the vascular injuries registered in the Swedvasc. Lethal outcome was more common (4.9%) among patients suffering IVIs than among non-iatrogenic vascular injuries (2.5%). Risk factors for death were age, diabetes, renal insufficiency and obstructive lung-disease.Fifty-two patients died within 30 days after IVI. The most common lethal IVIs were puncture during endovascular procedures (n=24, 46%), penetrating trauma during open surgery (11) and occlusion after compression (6). Symptoms were peripheral ischemia (n=19), external bleeding (14), and hypovolemic chock without external bleeding (10). Most died within two weeks (n=36, 69%). After >2 weeks the IVI as a cause of death was uncertain.Among 193 insurance claims after vascular surgery during 2002-2007, nerve injuries (91) and wound infections (22) dominated. Most patients suffered permanent injuries, three died. Patients with insurance claims were correctly registered in the Swedvasc in 82%.In 32 cases of popliteal artery injury during knee arthroplasty symptoms were bleeding (n=14), ischaemia (n=7) and false aneurysm formation (n=11). Only twelve injuries (38%) were detected intraoperatively. Patency at 30 days was 97%, but only seven (22%) patients had complete recovery. Six of those had intraoperative diagnosis of popliteal injury and immediate vascular repair.In conclusion, registration of IVIs is increasing and outcome is often negatively affected by diagnostic and therapeutic delay. Not all fatalities after IVIs are attributable to the injury itself. The most common causes of insurance claims after vascular surgery were nerve injuries, and 82% were correctly registered in Swedvasc.
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| 10. |
- Sörelius, Karl, 1981-
(författare)
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Aortic infections : The Nadir of Vascular Surgery
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aortic infections are rare, life-threatening and constitute a major challenge in surgical management. This thesis aims to evaluate short – and long-term outcome of endovascular aortic repair (EVAR) for mycotic aortic aneurysms (MAA) and the subsequent risk of recurrent infections, changes in surgical practice over time for abdominal MAAs in Sweden and outcome for different treatment modalities, as well as the risk of secondary vascular infection after treatment with Open abdomen after aortic surgery.Paper I, a retrospective single centre study of patients with MAA treated with EVAR, demonstrated a good short-term outcome, 91% survival at 30-days, and acceptable mid-term survival, 73% at 1-year.Paper II, a retrospective international multicentre study of patients treated with EVAR for MAA, confirmed the results in paper I, and showed that EVAR is feasible and for most MAA patients a durable treatment option, 5-year survival was 55% and 10-year 41%. A total of 19% died from an infection-related complication, mostly during the first postoperative year. Non-Salmonella-positive culture was a predictor for late infection–related death.Paper III, a population-based cohort study on all abdominal MAAs operated on between 1994-2014 in Sweden. Overall survival was 86% at 3-months, 79% at 1-year and 59% at 5-years. The survival was significantly better after endovascular compared to open repair up to 1-year without increasing recurrence of infection or reoperation, thereafter there was no difference. After 2001 EVAR constituted 60 % of all repairs, thus indicating a paradigm shift in treatment for abdominal MAAs in Sweden.Paper IV, a prospective multicentre study of patients treated with open abdomen after aortic surgery. Infectious complications, such as graft infections, occurred after intestinal ischaemia and prolonged OA-treatment, and were often fatal.
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