| 1. |
- Vidarsson, Bjarni, 1979-
(författare)
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Complications in bariatric surgery with focus on gastric bypass
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 2. |
- Edholm, David
(författare)
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Gastric Bypass : Facilitating the Procedure and Long-term Results
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Gastric bypass achieves weight loss in the morbidly obese. Preoperative weight loss is used to reduce the enlarged fatty liver that otherwise reduces visibility during surgery. The purpose of gastric bypass is to provide patients with long-term weight loss. The aim of this thesis was to investigate the result of preoperative low calorie diet on liver volume and to evaluate the long-term result of gastric bypass.Paper I showed that four weeks of low calorie diet reduces intrahepatic fat by 40% and facilitates surgery mainly through improved visualisation. Paper II demonstrated that all of the reduction of liver volume occurs during the first two weeks of treatment with low calorie diet. In paper I liver volume was reduced by 12% and in paper II by 18%. Paper III focused on long-term results and showed that gastric bypass achieves a mean 63% excess body mass index loss in obese patients after 11 years. However, of these 40% undergo abdominoplasty and 2% require additional bariatric surgery. Only 24% adhere to the lifelong recommendation on multivitamins and 72% to Vitamin B12 recommendations. Paper IV evaluated gastric bypass as a revisional procedure after earlier restrictive surgery had failed. Similar weight results as after primary gastric bypass are attained. No patient taking vitamin B12 supplementation was deficient at follow-up, regardless of whether the vitamin was taken as a pill or as intramuscular injections.
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| 3. |
- Jestin Hannan, Christine
(författare)
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Esophageal and Gastroesophageal Junctional Cancer : Improving Patient selection, Treatment and Care
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Esophageal cancer is the sixth most common cause of cancer-related death. Choice of surgical approach and individualized treatment is crucial. The aims of this thesis were to evaluate the introduction of minimally invasive esophagectomy (MIE) regarding oncological results and postoperative complications. To investigate radiological differences in pulmonary complications between MIE and open technique by studying computed tomography (CT). To evaluate geographical differences in intention for curative treatment and their association to survival. As well as to further explore these differences by comparing assessments of tumor stage (TNM) and treatment recommendations in anonymized cases at regional multidisciplinary cancer conferences (MCC).A comparison of 51 MIE (21 hybrid and 30 totally minimally invasive) and 65 open resections in 2007-2016, showed an increased lymph node yield in the MIE group, 18 (13–23) vs. 12 (8–16) median (IQR), p<0.001. The result was confirmed in a multivariate regression model (adjusted odds ratio 3.15 [1.11–8.98], p=0.03). Postoperative complications did not differ between the groups.When comparing CT after open esophagectomy (n=20) and MIE (n=20), no ipsilateral differences in the areas of atelectasis or pleural effusion were seen. Nor did the groups differ in the proportion of patients with clinically important atelectasis (dx: 30% vs. 25%, sin: 65% vs. 65%) or pleural effusion (dx: 15% vs. 15%, sin: 65% vs. 45%).A total of 5959 esophageal cancer patients, diagnosed 2006-2015 in Sweden, were identified from the National Register for Esophageal and Gastric Cancer (NREV). In a multivariable analysis, a higher rate of treatment with curative intent (time ratio 1.17 [1.05-1.30], p<0.001) and a higher resection rate (time ratio 1.24 [1.12-1.37], p<0.001) were associated with improved survival.Fifty anonymized esophageal cancer cases were distributed to five expert MCCs. In estimations of T-stage, the MCCs were in total agreement in eight of 50 cases (16%). For N-stage, total agreement was seen in 17 cases (34%) and for clinical M-stage in 34 cases (68%). The MCCs agreed on recommended treatment in 26/50 cases (52%). In conclusion, the introduction of MIE resulted in a larger lymph node yield, without increased risk for complications. No difference in postoperative pleural effusion and atelectasis was seen on computed tomography five days after open esophagectomy compared with MIE. Patients diagnosed in a county with a higher curative intention rate and a higher rate of surgery had better five-year survival and there are differences in assessment of esophageal cancer patients at different MCCs.
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| 4. |
- Löfling Skogar, Martin, 1983-
(författare)
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Bariatric Surgery : Outcomes after Gastric Bypass and Duodenal Switch
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Obesity is associated with increased morbidity and mortality. A BMI >40 kg/m2 shortens life expectancy by about 10 years. The obesity related comorbidities diabetes, hypertension, dyslipidemia and sleep apnea contributes to the increased risk of cardiovascular events. There is also an increased risk of some forms of cancer (e.g. colon, breast, and prostate cancer) as well as mental illness (depression and low self-esteem). Bariatric surgery is indicated for those with a BMI >35 kg/m2. Unfortunately, there are an increasing number of patients seeking bariatric surgery who are super obese (BMI >50 kg/m2), a condition more difficult to treat because of insufficient weight loss with standard operations, like the Roux-en-Y Gastric Bypass (RYGB). Therefore some surgeons advocate the Duodenal Switch (DS) in super obese patients, because DS results in greater and more sustained weight loss. However, DS is a technically more challenging operation and is associated with an increased risk of malnutrition and surgical complications. There are also concerns about an excessive loss of fat-free mass during weight loss after RYGB and especially after DS.This thesis focuses on weight-loss, effect on comorbidities, quality of life and complications after DS and RYGB, respectively, with comparisons between the two procedures in patients with super obesity. DS resulted in a superior weight loss compared to RYGB (paper I, II and III) and body composition after weight loss did not differ compared with non-operated controls with the same BMI after surgery, for neither DS nor RYGB (paper I). Both DS and RYGB resulted in an improved metabolic control (paper II and III), but the effect on diabetes and hypertension was greater and maintained in the long-term after DS (paper III). Both DS and RYGB resulted in an improved physical quality of life, with greater improvements after DS (paper III). However, complications and long-term adverse effects were more common after DS (paper II and IV).In conclusion, the superior weight loss and greater improvements in several obesity-related comorbidities after DS must be weighed against the increased risk of complications and long-term adverse effects compared to RYGB.
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| 5. |
- Sima, Eduardo, 1975-
(författare)
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Gastric bypass : Technical aspects and long-term results
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Roux-en-Y gastric bypass (RYGBP) achieves superior short- and long-term weight loss compared to other weight loss modalities. Different operative techniques have been developed to technically facilitate the surgical procedure, with consequences in the form of an array of postoperative complications and gastrointestinal symptoms. Furthermore, as our follow-up on operated patients extends beyond the first postoperative years, it becomes apparent that a significant number of patients experience unsatisfactory weight result. Current research is just starting to chart factors associated with postoperative long-term weight regain with the ultimate goal of preventing it.In Paper I it is found that the linear stapled technique for the gastrojejunostomy in laparoscopic RYGBP is associated with shorter operative time, in-hospital stay and a lower incidence of surgical site infections and anastomotic strictures compared to the circular stapled technique. Paper II demonstrates that, despite no differences in weight result, the 21-mm circular stapled technique for the gastrojejunostomy is associated with a higher incidence of vomiting and endoscopic anastomotic dilatations compared to the 25-mm circular stapled technique and the linear stapled technique in the long-term after RYGBP. Paper III shows that despite differences in body composition, long-term weight responders and non-responders after RYGBP did not differ in resting, glucose-induced or activity-related energy expenditure. Lastly Paper IV shows long-term weight result is associated with fasting levels of leptin and ghrelin, and that the response of these hormones to a glucose load might contribute to perpetuate obesity.
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| 6. |
- Abrahamsson, Niclas, 1976-
(författare)
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On the Impact of Bariatric Surgery on Glucose Homeostasis
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Obesity has grown to epidemic proportions, and in lack of efficient life-style and medical treatments, the bariatric surgeries are performed in rising numbers. The most common surgery is the Gastric Bypass (GBP) surgery, with the Biliopancreatic diversion with duodenal switch (DS) as an option for the most extreme cases with a BMI>50 kg/m2.In paper I 20 GBP-patients were examined during the first post-operative year regarding the natriuretic peptide, NT-ProBNP, which is secreted from the cardiac ventricles. Levels of NT-ProBNP quickly increased during the first post-surgery week, and later established itself on a higher level than pre-surgery.In paper II we report of 5 patient-cases after GBP-surgery with severe problems with postprandial hypoglycaemia that were successfully treated with GLP-1-analogs. The effect of treatment could be observed both symptomatically and in some cases using continuous glucose measuring systems (CGMS).In paper III three groups of subjects; 15 post-GBP patients, 15 post-DS, and 15 obese controls were examined for three days using CGMS during everyday life. The post-GBP group had high glucose variability as measured by MAGE and CONGA, whereas the post-DS group had low variability. Both post-operative groups exhibited significant time in hypoglycaemia, about 40 and 80 minutes per day <3.3mmol/l and 20 and 40 minutes < 2.8mmol/l, respectively, longer time for DS-group. Remarkably, only about 20% of these hypoglycaemic episodes were accompanied with symptoms.In Paper IV the hypoglycaemia counter regulatory system was investigated; 12 patients were examined before and after GBP-surgery with a stepped hypoglycaemic hyperinsulinemic clamp. The results show a downregulation of symptoms, counter regulatory hormones (glucagon, cortisol, epinephrine, norepinephrine, growth hormone), incretin hormones (GLP-1 and GIP), and sympathetic nervous response.In conclusion patients post bariatric surgery exhibit a downregulated counter regulatory response to hypoglycaemia, accompanied by frequent asymptomatic hypoglycaemic episodes in everyday life. Patients suffering from severe hypoglycaemic episodes can often be treated successfully with GLP-1-analogues.
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| 7. |
- Fanni, Giovanni, et al.
(författare)
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Effects of gastric bypass surgery on brain connectivity responses to hypoglycemia
- 2023
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Ingår i: Endocrine. - : Springer Nature. - 1355-008X .- 1559-0100 .- 0969-711X. ; 79:2, s. 304-312
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionRoux-en-Y gastric bypass (RYGB) leads to beneficial effects on glucose homeostasis, and attenuated hormonal counterregulatory responses to hypoglycemia are likely to contribute. RYGB also induces alterations in neural activity of cortical and subcortical brain regions. We aimed to characterize RYGB-induced changes in resting-state connectivity of specific brain regions of interest for energy homeostasis and behavioral control during hypoglycemia.MethodTen patients with BMI > 35 kg/m2 were investigated with brain PET/MR imaging during a hyperinsulinemic normo- and hypoglycemic clamp, before and 4 months after RYGB. Hormonal levels were assessed throughout the clamp. Resting-state (RS) fMRI scans were acquired in the glucose-lowering phase of the clamp, and they were analyzed with a seed-to-voxel approach.ResultsRS connectivity during initiation of hypoglycemia was significantly altered after RYGB between nucleus accumbens, thalamus, caudate, hypothalamus and their crosstalk with cortical and subcortical regions. Connectivity between the nucleus accumbens and the frontal pole was increased after RYGB, and this was associated with a reduction of ACTH (r = −0.639, p = 0.047) and cortisol (r = −0.635, p = 0.048) responses. Instead, connectivity between the caudate and the frontal pole after RYGB was reduced and this was associated with less attenuation of glucagon response during the hypoglycemic clamp (r = −0.728, p = 0.017), smaller reduction in fasting glucose (r = −0.798, p = 0.007) and less excess weight loss (r = 0.753, p = 0.012). No other significant associations were found between post-RYGB changes in ROI-to-voxel regional connectivity hormonal responses and metabolic or anthropometric outcomes.ConclusionRYGB alters brain connectivity during hypoglycemia of several neural pathways involved in reward, inhibitory control, and energy homeostasis. These changes are associated with altered hormonal responses to hypoglycemia and may be involved in the glucometabolic outcome of RYGB.
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| 8. |
- Hedberg, Jakob, 1972-
(författare)
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Gastrointestinal Physiology and Results following Bariatric Surgery
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The number of operations for morbid obesity is rising fast. We have examined aspects of postoperative physiology and results after bariatric surgery. The pH in the proximal pouch after Roux-en-Y gastric bypass (RYGBP) was investigated with catheter-based and wire-less technique. Gastric emptying, PYY-levels in the fasting state and after a standardized meal was evaluated after biliopancreatic diversion with duodenal switch (DS). A clinical trial was undertaken, comparing DS to RYGBP in patients with BMI>48. Main outcome variables were safety and long-term weight results as well as abdominal symptoms and laboratory results. Patients with stomal ulcer had significantly lower pH in their proximal gastric pouch as compared to asymptomatic control subjects. Long-time pH measurements with the wire-less BRAVO-system were feasible and demonstrated pH<4 in median 10.5% of the time in asymptomatic post-RYGBP patients. After DS, the T50 of gastric emptying was 28±16 minutes. PYY-levels were higher after DS than in age-matched control subjects. BMI-reduction was greater after DS (24 BMI-units) than after RYGBP (17 BMI-units) in median 3.5 (2.0-5.3) years after surgery (p<0.001). Fasting glucose and HbA1c levels were lower one and three years after DS as compared to RYGBP. On the other hand, DS-patients reported having more diarrhea and malodorous flatus. This thesis has resulted in deepened knowledge. Acid produced in the proximal pouch is an important pathogenetic factor in the development of stomal ulcer after RYGBP. However, symptom-free patients have an acidic environment in the proximal Roux-limb as well. After DS, gastric emptying is fast, but not instantaneous, and PYY-levels are high. DS results in superior weight reduction and better glucose control as compared to RYGBP in patients with BMI>48. We believe that DS has a place in surgical treatment of the super-obese, even though symptoms of diarrhea and malodorous flatus are more common after DS.
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| 9. |
- Linder, Gustav, 1981-
(författare)
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Esophageal- and Gastroesophageal Junctional Cancer : Aspects on Staging, Treatment and Results
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Esophageal- and gastroesophageal junctional (GEJ) cancer is the sixth cause of cancer-related death worldwide. Some improvements in care are attributed to nationwide disease-specific registries, preoperative staging and increased understanding of mechanisms affecting patient selection. Surgery, however, is a cornerstone for treatment where minimally invasive surgery and increased understanding of perioperative physiology may be beneficial. The aims of this thesis were to validate the Swedish national registry for esophageal and gastric cancer (NREV) and to explore mechanisms in patient selection, perioperative physiology, treatment-related outcomes and staging.A validation study with re-abstracted data on 400 patients determined NREV comparable to other similar registries and to have a completeness of 95.5 %. Overall accuracy was 91.1 % throughout the registry and timeliness to reporting was adequate.In a cohort of 4112 patients from NREV, high education level was associated with an increased probability of being allocated to curative treatment, as was the presence of a multidisciplinary treatment conference. High education level was associated with improved survival.By measuring intramucosal pH (pHi) in 32 patients, to describe perfusion in the gastric conduit during esophagectomy, a reduction in perfusion was seen at all surgical steps altering vascular supply to the conduit but foremost after gastric tube construction by linear stapling. Patients with low pHi on the first postoperative day were more prone to anastomotic insufficiency.In 116 patients undergoing esophagectomy (65 open and 51 minimally invasive), a retrospective cohort study regarding surgical oncological results and postoperative complications was conducted. Lymph node yield was increased, peroperative blood loss and in-hospital stay were reduced with minimally invasive esophagectomy. Postoperative complications were unaffected by surgical approach. In a prospective study of nineteen patients, whole-body integrated PET/MRI was compared to PET/CT in preoperative staging. PET/MRI was safe and feasible. Accuracy and correlations between modalities were good regarding tumor characteristics and N- and M-staging. In T-staging there were discrepancies indicating differences between modalities.The thesis presents data on the quality of NREV for future research and elaborates on patient selection, staging, perioperative physiology and treatment-related outcomes for patients with esophageal- and GEJ cancer.
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| 10. |
- Stenberg, Erik, 1979-, et al.
(författare)
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Association between attention deficit hyperactivity disorder and outcomes after metabolic and bariatric surgery : a nationwide propensity-matched cohort study
- 2023
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Ingår i: Surgery for Obesity and Related Diseases. - : Elsevier. - 1550-7289 .- 1878-7533. ; 19:2, s. 92-100
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The risks and benefits of metabolic and bariatric surgery for patients with attention deficit hyperactivity disorder (ADHD) remain to be investigated.OBJECTIVE: The aim of this study was to assess short- and long-term outcomes after metabolic and bariatric surgery in patients with previous ADHD compared with matched control individuals.SETTING: Registry based.METHODS: This 2-staged matched-cohort study included all adults with a body mass index of ≥30 kg/m2 who underwent primary Roux-en-Y gastric bypass or sleeve gastrectomy from 2007 until 2017 registered in the Scandinavian Obesity Surgery Registry. Patients with prescribed medication for ADHD were matched with control individuals without ADHD with a follow-up of up to 11 years after surgery.RESULTS: Among 1431 patients with ADHD and 2862 control individuals (mean body mass index, 42 kg/m2; mean age, 35 years), no difference in weight loss or follow-up attendance over 2 years was seen. ADHD was associated with a higher risk for early postoperative complications (odds ratio [OR] = 1.31; 95% confidence interval [CI], 1.05-1.63), self-harm (hazards ratio [HR] = 1.39; 95% CI, 1.11-1.75), and substance abuse (HR = 1.34; 95% CI, 1.16-1.55), while associations with overall mortality (HR = 1.42; 95% CI, .99-2.03), major adverse cardiovascular and cerebrovascular events (HR = 1.93; 95% CI, .98-3.83), and effects on obesity-related diseases were uncertain. ADHD was associated with a lower health-related quality of life in all aspects before surgery. These differences increased for mental and obesity-related aspects but remained unchanged over time for physical aspects.CONCLUSIONS: Compared with patients without ADHD, patients treated pharmacologically for ADHD experience similar weight loss and remission of obesity-related diseases without an increased risk for serious complications but report a lower health-related quality of life and have an increased risk of substance abuse and self-harm. This further emphasizes the need for close follow-up care for this group of individuals.
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