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Coming dissertations at MedFak

  • Complications in bariatric surgery with focus on gastric bypass Author: Bjarni Vidarsson Link: Publication date: 2020-09-18 14:14

    Obesity is rising in pandemic proportions. At present, one third of the world’s population has become overweight or obese, and estimates predict 60% in 2030. Thus, the problem is gigantic. Obesity is associated with numerous diseases such as diabetes, high blood pressure, sleep apnea and cancer. Untreated obesity decreases life expectancy by about 10 years. Gastric bypass has been one of the cornerstones of surgical treatment. Since 1994 this is done by laparoscopic technique (LRYGB)

    In this thesis, we have primarily used data from our national quality register, the Scandinavian Obesity Surgical Registry (SOReg), on patients that have been operated with LRYGB. In the first paper, we evaluated the use of a novel suture for closing the gastrojejunostomy (upper anastomosis). Paper II and III focused on incidence, risk factors, treatment and outcome of anastomotic leaks. Paper IV compares the weight results, quality of life, use of medications and healthcare consumption in patients suffering from a serious complication within 30 days after LRYGB.

    In Paper I, the use of the barbed suture resulted in shorter operative time compared to a standard polyfilament, without increased risk for complications. Paper II showed that the incidence of anastomotic leaks at the gastrojejunostomy was 0.6%. Risk factors were male sex, higher age (≥49 years), diabetes, conversion to open surgery and prolonged operative time (≥ 90 minutes). Almost all patients were reoperated and 1% died. Paper III showed that the incidence of small bowel leaks was 0.3% and these leaks were associated with prolonged operative time, and surgery at a low-volume centre for leaks at the enteroaenteral anastomosis. Surgical re-intervention was common. Paper IV showed that severe complications within 30 days postoperatively after LRYGB occurred in 2.9% of cases. Two years later, the patients still reported inferior quality of life and had a higher use of antidepressants, proton pump inhibitors and opioids compared to uncomplicated cases. The need for additional in-hospital care was higher, even after the first 30 days.

    In conclusion, the novel barbed suture reduced operative time without increasing risks. Anastomotic leaks are rare, but serious complications in LRYGB do affect the patient in numerous ways and increase healthcare costs.

  • Epicardial ablation - a study evaluating thoracoscopic and surgical ablation procedures for patients with intractable atrial fibrillation Author: Johan Probst Link: Publication date: 2020-09-04 08:26

    Atrial fibrillation (AF) is a common condition, increasing in prevalence with age. Symptoms can be severe and quality of life is affected in patients suffering from AF. Treatment regimes aim to alleviate symptoms through rate or rhythm control. Rhythm control can be achieved effectively in early stages of AF with catheter ablation aiming for pulmonary vein isolation (PVI) however, in more advanced stages of the disease a surgical ablation is warranted if rhythm control is the goal.

    The aim of this thesis was to evaluate the thoracoscopic epicardial left atrial surgical procedure for AF (TELA-AF) in patients suffering from highly symptomatic, mainly longstanding persistent AF (LPAF). The hypothesis was that TELA-AF would be effective in treating LPAF and that quality of life (QoL) would increase accordingly.

    This thesis second hypothesis was that restoration of sinus rhythm would improve QoL in patients with permanent AF undergoing concomitant mitral valve surgery (MVS) and left atrial cryoablation compared to MVS alone.

    The TELA-AF surgical technique included pulmonary vein isolation, left atrial "box-lesion" and partial vagal denervation. Patients were followed with clinical evaluation, seven-day Holter electrocardiogram, symptom severity questionnaire (SSQ)and a short form QoL questionnaire (SF-36), six and 12 months after surgery and again after ten years.

    The concomitant MVS study was a sub-study of the randomized double-blinded SWEDMAF trial. Patients in permanent AF, accepted for MVS were randomized to MVS or MVS and cryo-ablation of the left atria. Patients self-reported QoL before and one year after surgery in the SF-36 questionnaire.

    Twelve months after the TELA-AF procedure freedom from AF was 83 % although 12 % suffered from an iatrogenic atrial tachycardia post-surgery. The SSQ scores improved significantly from baseline. The SF-36 scores were similar to patients suffering from severe chronic disease at baseline but were not significantly different from an age-matched normal population at follow-up.

    Ten years after surgery freedom from AF was 22 %, a significant reduction. Quality of life scores were however significantly better than baseline.

    Patients randomized to concomitant surgery experienced a significant increase in QoL one year after surgery, but there was no difference in QoL scores compared to the MVS-alone group.

    In conclusion, severe symptoms in AF patients translate to QoL scores as low as those observed in patients with severe chronic diseases. The TELA-AF procedure can alleviate AF related symptoms and improve QoL to the same level as a normal population in the short term. In the long term QoL can be maintained at a high level although displaying AF recurrence according to guidelines, challenging the concept of 30 seconds arrhythmia as a valid endpoint.

    We could not show any benefit in a concomitant surgery for patients in permanent AF accepted for MVS. It is therefore important to balance the benefits and side effects in both short- and long-term perspective in order to justify the addition of a surgical AF ablation during MVS.

  • Autoimmunity in Africa: Comparing Systemic Lupus Erythematosus and Anti-phospholipid Antibodies in Sudan and Sweden Author: Sahwa Elbagir Link: Publication date: 2020-08-27 12:21

    Systemic Lupus Erythematosus (SLE) is a chronic immune complex (IC)-mediated disease with variable prevalence worldwide, reported to be more common in Africans, Hispanics and Asians than in Caucasian populations. Expression of autoantibodies might vary between different ethnic populations due to environmental and genetic factors. Antiphospholipid antibodies (aPL) react with several antigenic targets of negatively charged phospholipids and/or associated plasma proteins. In this thesis we have studied the immunological and clinical characteristics of SLE in patients from Sudan and Sweden using an identical methodology. We have also investigated the occurrence of aPL during healthy pregnancies in both countries.

    Sudanese patients with SLE were younger, had shorter disease duration and suffered from more organ damage compared to Swedish patients. Neurological involvement, predominantly in young patients, was the main contributor to organ damage among the Sudanese patients. When comparing anti-nuclear antibody (ANA) specificities in IC between Sudanese and Swedish patients, different results from ANA detected in serum was observed. While serum ANA levels were mainly higher in Swedish SLE patients, levels of most ANA specificities in IC, particularly anti-chromatin specificities, were increased in Sudanese patients. In both cohorts, ANA in IC associated with more active SLE. Sudanese SLE patients had a higher prevalence of IgA aPL using common assay cut-off points. However, aPL levels among controls were also higher in Sudan, and when cut-offs were adjusted based on national controls the difference in prevalence between the patient groups was no longer evident. A more recently defined test measuring antibody against the phosphatidylserine/prothrombin complex was the best aPL predictor of thrombosis in Swedish SLE patients, independent of cardiovascular risk factors and antiphospholipid antibody syndrome criteria tests. Levels of IgA aPL, particularly anti-β2 glycoprotein I, were higher in normal pregnancies of healthy women from Sudan. This was not observed in Swedish pregnancies, and it was not due to reactivity against domain 1 of the β2 glycoprotein I molecule.

    Levels of autoantibodies differed both for patients and healthy individuals from Sudan and Sweden, and the occurrence of antibodies among patients depended on the cut-offs used. Adjustments to national cut-offs revealed more associations between autoantibody occurrence and clinical manifestations in Sudan. We recommend that the evaluation of autoantibody prevalence and clinical significance in autoimmune diseases in populations of African origin should rely on cut-offs based on controls from the same population, both in research and clinical contexts.