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Coming dissertations at MedFak

  • Abdominal compartment syndrome and colonic ischaemia after abdominal aortic aneurysm repair in the endovascular era Author: Samuel Ersryd Link: Publication date: 2020-11-05 09:56

    Abdominal Compartment Syndrome (ACS) and colonic ischaemia (CI) are serious and potentially lethal complications after open (OSR) and endovascular repair (EVAR) of ruptured (rAAA) and intact (iAAA) abdominal aortic aneurysms. The aims of this thesis were to investigate the incidence, outcome, and risk factors associated with ACS (Papers I-III) and to evaluate extraluminal colonic tonometry for postoperative surveillance of colonic perfusion (Paper IV).

    Papers I-III combined data from the nationwide Swedish vascular registry (Swedvasc) (2008-2015) with case records and radiologic imaging. Paper I investigated incidence and outcome of ACS. The incidence was approximately 7% for both EVAR and OSR after rAAA and 1.6% after OSR and 0.5% after EVAR for iAAA. ACS was associated with a more than two-fold (59% vs 27%) 90-day mortality after rAAA and six-fold (19% vs 3%) after iAAA. Paper II investigated risk factors and outcome among subgroups. Risk of death could not be attributed to a specific main pathology of ACS: CI, postoperative bleeding and general oedema, nor to timing of decompressive laparotomy in relation to AAA surgery. However, the duration of intra-abdominal hypertension (IAH) predicted the need for renal replacement therapy. Paper III investigated risk factors after EVAR for rAAA. ACS was rare without pronounced pre- or intraoperative physiologic derangement associated with circulatory instability. Aortic morphology did not impact ACS development, nor did presence of a patent inferior mesenteric and lumbar arteries, known risk factors for type II endoleak. Paper IV studied patients operated on for iAAA/rAAA (n=27), and demonstrated extraluminal colonic tonometry safe, reliable and indicative of CI among all affected patients (n=4).

    In conclusion, ACS was common after rAAA repair, with poor outcome irrespective of AAA repair technique and indication for repair. Outcome did not differ depending on the main pathophysiological finding associated with ACS development, while a longer duration of IAH increased the risk of renal replacement therapy. ACS after EVAR for rAAA was largely associated with pre- and intraoperative physiologic factors. These findings highlight the importance of vigilant intra-abdominal pressure measurement after rAAA repair and in case of haemodynamic instability, as well as timely interventions to treat IAH. Extraluminal colonic tonometry appears promising for surveillance of postoperative colonic perfusion.

  • Symbol-based communication intervention for individuals with Rett syndrome : Current practices, assessment of visual attention, and communication partner strategies Author: Helena Wandin Link: Publication date: 2020-11-04 13:44

    Individuals with Rett syndrome need extensive support to actively participate in social interaction and to develop their communication. The overall aim of this thesis was to investigate communication intervention for individuals with Rett syndrome, especially aided symbol-based communication and partner strategies.

    Study I was a cross-sectional survey exploring services provided by speech language pathologists (SLPs) in Sweden. Communication aids were often used in the intervention and were found to be useful. Few SLPs used systematic tools for assessment and evaluation and communication partners were often instructed through informal conversations.

    In study II, a tool (AVAI) for assessing visual attention in interaction was developed and its psychometric properties were explored. AVAI was also used as an outcome measure in study III. In both studies, the tool was found to be reliable, able to detect change and acceptable to the participants.

    In study III, a single case experimental design was applied to evaluate an intervention consisting of aided language modelling whilst using responsive partner strategies and a gaze-controlled device. The adult participants with Rett syndrome (n=3) increased their expressive communication following individual learning patterns. The intervention was appreciated by the participants’ social network.

    Study IV was a case study exploring and describing a communication partner’s use of responsive and scaffolding partner strategies in interaction with individuals with Rett syndrome (n=3). The use of these strategies varied in interaction with different individuals with Rett syndrome. The communication partner responded more frequently to communication through a gaze-controlled device than unaided communication.

    In conclusion, gaze-controlled devices should be considered in communication intervention with individuals with Rett syndrome. Systematic tools and procedures should be applied in interventions, which is not the case in current clinical practice. Adults with Rett syndrome are able to develop their communication which highlights the need for communication support throughout their lifetime.    

  • Chronic lymphocytic leukemia : Studies from genetics to epidemiology with focus on the impact of different treatments Author: Mattias Mattsson Link: Publication date: 2020-11-02 12:27

    The progress in our understanding of the biology and pathophysiology of chronic lymphocytic leukemia (CLL), as well as the development of new treatments, necessitates additional research on; (i) the impact of different therapies within subgroups of CLL patients, (ii) solid epidemiological data on the prevalence of CLL and on comorbidities within the CLL population, and (iii) new means of prognostication, as the value of traditional prognostic markers is uncertain when applied to new treatments.

    In paper I we studied the efficacy of chemo(immuno)therapy in stereotyped subsets #1 and #2. We could demonstrate that the improvement in survival seen over time in CLL in general, was not observed in these two subgroups. This suggests that alternative treatment options should be explored in these patients, and that subset assignment can be used as a predictive tool.

    In paper II we could demonstrate a significant rise (56%) in the prevalence of CLL in Sweden from 2000 to 2015. We then developed a model to estimate the future prevalence of CLL. Applying this, we estimated a further increase in the absolute number of CLL patients with approximately 70% over the next 20 years, a rise with important health-economic impact.

    In paper III we showed that 32% of all CLL patients were diagnosed with at least one cardiovascular disease (CVD) within 10 years before diagnosis, as well as 37% before start of treatment. Of these, 81% had ≥3 concomitant CVD diagnoses. Within 5 years after start of treatment, an additional 28% of patients (without previous CVD) were diagnosed with a CVD. This is particularly important considering the known cardiovascular side-effects of BTK-inhibitors.

    In paper IV we studied clonal dynamics in 10 patients with high-risk CLL during treatment with ibrutinib, with a long-term clinical follow-up. Seven out of 10 displayed major clonal shifts and 5 of these experienced disease progression, which was not seen in the 3 patients without clonal shifts. We suggest further studies of clonal shifts as a new means of prognostication in patients treated with BTK-inhibitors.

    We conclude that; (i) CLL patients of subsets #1 and #2 do not benefit of “old” treatments and should be explored for alternatives, (ii) the prevalence in CLL is higher than previously described with an expected continuing rise, (iii) the burden of cardiovascular comorbidities in CLL is high, and (iv) the occurrence of clonal shifts during ibrutinib treatment suggests inferior outcome.