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Coronary artery bypass grafting (CABG) is the most common cardiac surgical operation performed in western countries, and is also increasingly being performed in developing countries. However the long-term results of CABG using the saphenous vein graft have not been satisfactory. Surgeons have therefore been seeking a better conduit. The radial artery (RA) is a potentially suitable alternative conduit and has to date provided good early results. This thesis investigates the utility of the RA as a coronary artery bypass graft from a number of perspectives. It demonstrates the safety of RA harvesting by examining hand collateral circulation using anatomical dissection, physical examination using the modified Allen test, measuring digital blood pressure, and examining the flow velocity in the digital artery using Doppler ultrasound. Anatomical examinations revealed consistent continuity between the RA and ulnar artery in the hand through either superficial or deep palmar arches. The modified Allen test was found to be useful as a screening test compared with the Doppler dynamic test and digital blood pressure index. A histological comparison was made between pre-existing intimal disease in the RA compared with that in the standard conduit the internal thoracic artery (ITA). The RA showed a higher prevalence and degree of intimal disease than ITA. Risk factors for intimal hyperplasia in the RA were age, diabetes, smoking and peripheral vascular disease. The only predictor for medial calcification was age. (For complete abstract open document)

The ultimate success of bypass surgery depends on the construction of a technically perfect bypass graft to an appropriate coronary vessel using a conduit which will remain durable for the lifetime of the patient. This thesis explores methods to improve coronary surgery by enhancing intraoperative imaging and conduit selection in the operating room. It is known that technical errors in graft construction cause failure of up to 12% of coronary bypass grafts in the operating room. We performed investigations of a new technique of intraoperative fluorescence angiography using indocyanine green dye to determine graft patency. We developed optimal methods of obtaining images and preliminary investigations revealed the technique was highly reproducible. In a follow-up trial, we demonstrated that over 80% of technical errors which would otherwise have been missed were identifiable with indocyanine green angiography, while only 25% of these errors were identified by transit-time ultrasonic flow measurement, the current clinical standard. We also determine that coronary surgery with indocyanine green angiographic graft patency verification was associated with less perioperative myocardial injury than bypass surgery without graft patency assessment. The long term graft patency of saphenous vein grafts is sub-optimal, with over 40% of such grafts totally occluded and a further 30% significantly diseased at ten years. We attempted to improve these outcomes by increasing the use of arterial grafts, which are less prone to intimal hyperplasia. In a multicentre clinical trial, we demonstrated a 40% relative risk reduction in graft occlusion at one year when radial arteries were used as bypass conduits versus saphenous veins. We identified that women and patients with small coronary vessels maximally benefited from radial artery bypass grafts. Conversely, in settings of less severe target vessel stenosis or concomitant peripheral vascular disease, saphenous veins performed as well as radial arteries. We have demonstrated that high quality imaging to identify technical errors during the operation, increased use of radial artery grafts and careful consideration of individual patient and target vessel characteristics can all improve graft patency. Future studies will be aimed at identifying the role of intraoperative imaging and arterial grafting in improving long-term clinical outcomes.

The ultimate success of bypass surgery depends on the construction of a technically perfect bypass graft to an appropriate coronary vessel using a conduit which will remain durable for the lifetime of the patient. This thesis explores methods to improve coronary surgery by enhancing intraoperative imaging and conduit selection in the operating room. It is known that technical errors in graft construction cause failure of up to 12% of coronary bypass grafts in the operating room. We performed investigations of a new technique of intraoperative fluorescence angiography using indocyanine green dye to determine graft patency. We developed optimal methods of obtaining images and preliminary investigations revealed the technique was highly reproducible. In a follow-up trial, we demonstrated that over 80% of technical errors which would otherwise have been missed were identifiable with indocyanine green angiography, while only 25% of these errors were identified by transit-time ultrasonic flow measurement, the current clinical standard. We also determine that coronary surgery with indocyanine green angiographic graft patency verification was associated with less perioperative myocardial injury than bypass surgery without graft patency assessment. The long term graft patency of saphenous vein grafts is sub-optimal, with over 40% of such grafts totally occluded and a further 30% significantly diseased at ten years. We attempted to improve these outcomes by increasing the use of arterial grafts, which are less prone to intimal hyperplasia. In a multicentre clinical trial, we demonstrated a 40% relative risk reduction in graft occlusion at one year when radial arteries were used as bypass conduits versus saphenous veins. We identified that women and patients with small coronary vessels maximally benefited from radial artery bypass grafts. Conversely, in settings of less severe target vessel stenosis or concomitant peripheral vascular disease, saphenous veins performed as well as radial arteries. We have demonstrated that high quality imaging to identify technical errors during the operation, increased use of radial artery grafts and careful consideration of individual patient and target vessel characteristics can all improve graft patency. Future studies will be aimed at identifying the role of intraoperative imaging and arterial grafting in improving long-term clinical outcomes.

Introduktion: Depression, ångest, stress och ätstörningsproblematik har visat sig ha en hög prevalens hos personer som lider av obesitas. Syfte: Att undersöka om och i så fall hur ångest och depression mätt i HADS förändras i en grupp som genomgått överviktskirurgi. Av intresse var också att undersöka om viktnedgång samt om preoperativa symtom på stress, hetsätning och känslomässigt ätande predicerar utfallet av symtom på ångest och depression postoperativt. Metod: 30 patienter som genomgått överviktskirurgi på Akademiska sjukhuset i Uppsala under våren 2011 inkluderades i studien. Dessa patienter hade innan genomgången operation och vid en uppföljning sex månader postoperativt besvarat olika screeningformulär avseende psykiskt välmående, ätstörningar och stress. Resultat: Preoperativa symtom på stress, hetsätning och känslomässigt ätande predicerar inte utfallet av symtom på ångest och depression sex månader postoperativt. Viktnedgång predicerar inte utfallet av symtom på ångest postoperativt, däremot kan viktnedgång predicera utfallet av symtom på depression sex månader efter operation. Ingen signifikant skillnad fanns mellan pre- och postoperativa symtom på ångest eller depression. Slutsats: I en grupp patienter där symtom på ångest och depression inte varit högt förekommande preoperativt kan det vara svårt att upptäcka förändringar i hur dessa patienter mår. Fler studier behövs för att kunna ge ett utökat professionellt stöd till denna patientgrupp. / Background: People with obesity have a high prevalence of depression, anxiety, stress and binge eating/emotional eating behaviours. Aim: To analyze if and how anxiety and depression measured with the Hospital and Anxiety Depression Scale change in a group of patients who have gone through Gastric Bypass surgery. Of interest was also to study if weight loss and preoperative symptoms in stress, binge- eating and emotional eating behaviours could predict anxiety and depression postoperatively. Method: 30 patients whom all gone through Gastric Bypass surgery in Uppsala University Hospital were included in the study. All patients had answered screening questionnaires about physically wellbeing, eating disorders and stress before surgery and six months postoperatively. Results: Preoperative symptoms of stress, binge eating and emotional eating disorders do not predict anxiety and depression postoperatively. Weight loss does not predict symptoms of anxiety postoperatively, but could predict symptoms of depression six months after Gastric Bypass surgery. There was no statistically significant difference between pre- and postoperative symptoms of anxiety and depression. Conclusion: Changes in wellbeing following Gastric Bypass surgery are difficult to identify in a group of patients where the occurrence of symptoms of anxiety and depression is low preoperatively. Further research is needed to find and develop professional support to this group of patients.

yes / Background The interaction between motivation to eat, eating behaviour traits and gut peptides following gastric bypass (GBP) surgery are not fully understood. Setting Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden. Method Appetite and hormone responses to a fixed liquid pre-load were assessed in 12 obese (BMI 45 ± 1.9 kg/m2) participants immediately before, 3 days, 2 months, and 1 year following gastric by-pass (GBP) surgery. Subjective appetite and plasma levels of ghrelin, leptin, insulin and GLP-1 were measured for a 3-hour postprandial period. Eating behaviour traits were also measured using the TFEQR18. Results There was a decrease in TFEQ Emotional Eating (EE) and Uncontrolled Eating (UE) from pre to 1-year post-surgery, but no significant change in Restraint. In addition, there was a reduction in subjective appetite ratings, and alterations in appetite peptides favouring an anorectic response. Pre-surgery EE was significantly related to fasting and AUC ghrelin; UE was associated with AUC desire to eat while there was a significant association between fasting desire to eat and ghrelin (fasting and AUC). 1 year post-surgery, UE was positively related to fasting insulin and Restraint was negatively associated with GLP-1. UE and subjective hunger were positively correlated, while the relationship between desire to eat and ghrelin remained. Conclusion The relationships amongst subjective appetite ratings, eating behaviour traits and appetite peptides in obese patients both before and at one-year post GBP surgery contribute to the reduction in a propensity to over-eat and weight loss.

Abstract The identification of risk factors for major adverse events after coronary artery bypass surgery is of main importance as it allows outcome prediction, facilitates preoperative patient selection and improves the quality of care. In the present clinical studies we have evaluated the impact of preoperative angiographic severity of a coronary artery disease and preoperative C-reactive protein (CRP) on the immediate outcome after coronary artery bypass surgery. We have reviewed the results of off-pump (OPCAB) versus conventional on-pump coronary artery bypass surgery (CCAB) in high risk patients. We have evaluated the impact of postoperative pulmonary artery blood temperature on the immediate outcome as well. In addition, we have investigated the incidence, timing and outcome of an atrial fibrillation (AF) related stroke after surgery. The multivariate analysis showed that among 2233 patients, the overall coronary angiographic score was predictive of postoperative death (p = 0.03; OR 1.027, 95% CI: 1.003–1.052) and of a low cardiac output syndrome (p = 0.04; OR 1.172, 95% CI: 1.010–1.218). The poor status of the proximal segment of the left circumflex coronary artery, the diagonal branches and the left obtuse marginal artery were most closely associated with adverse postoperative outcome. Patients (114/764) with a preoperative serum concentration of CRP ≥ 1.0 mg/dL had a higher risk of overall postoperative death (5.3% vs. 1.1%, p = 0.001), cardiac death (4.4% vs. 0.8%, p = 0.002), a low cardiac output syndrome (8.8% vs. 3.7%, p = 0.01). Among 179 high risk patients with an additive EuroSCORE6, the 30-day postoperative death and stroke rates were 7.5% and 6.0% in the OPCAB group, and 5.4% (p = 0.75) and 8.0% (p = 0.77) in the CCAB group, respectively. No significant differences were observed in other major outcome end-points between these non-randomised groups either. High pulmonary artery blood temperature on admission to the ICU among 1639 patients was significantly associated with an increased risk of overall postoperative death (p = 0.002), cardiac death (p = 0.03), and a low cardiac output syndrome (p < 0.0001), and was significantly correlated with prolonged length of the ICU stay (r = 0.095; p < 0.0001), and postoperative bleeding (ρ = –0.091; p = 0.001). Among 2,630 patients who underwent coronary artery bypass grafting (CABG), 52 (2.0%) experienced a postoperative stroke. Twelve out of these 52 patients (23.1%) died postoperatively. The ischemic cerebral event occurred after a mean of 3.7 days (0–33). In 19 patients (36.5%), atrial fibrillation preceded the occurrence of neurological complication. The angiographic severity of the coronary artery disease and the preoperative serum concentration of CRP predict postoperative outcome after a CABG operation. OPCAB can be performed safely in high-risk patients with results as satisfactory as those achieved with CCAB. CABG patients with a high pulmonary artery blood temperature on admission to the ICU seem to have a higher risk of postoperative adverse events. Atrial fibrillation occurring after coronary artery bypass grafting is a major determinant of a postoperative stroke.

The purpose of this study was to compare patients who underwent on- vs. off-pump coronary artery bypass surgery managed with a fast-track protocol. Between September 2012 and December 2018, n = 3505 coronary artery bypass surgeries were managed with a fast-track protocol in our specialized post-anesthesia care unit. Propensity score matching was applied and resulted in two equal groups of n = 926. There was no significant difference in ventilation time (on-pump 75 (55–120) min vs. off-pump 80 (55–120) min, p = 0.973). We found no statistically significant difference in primary fast-track failure in on-pump (8.2% (76)) vs. off-pump (6% (56)) groups (p = 0.702). The secondary fast-track failure rate was comparable (on-pump 12.9% (110) vs. off-pump 12.3% (107), p = 0.702). There were no significant differences between groups in regard to the post-anesthesia care unit, the intermediate care unit, and the hospital length of stay. Postoperative outcome and complications were also comparable, except for a statistically significant difference in PACU postoperative blood loss in on-pump (234 mL) vs. off-pump (323 mL, p < 0.0001) and red blood cell transfusion (11%) and (5%, p < 0.001), respectively. Our results suggest that on- and off-pump coronary artery bypass surgery in fast-track settings are comparable in terms of ventilation time, fast-track failure rate, and postoperative complications rate.

Truncal adiposity impairs ventilation in obese adults by altering normal ventilatory mechanics. Leptin, an inflammatory adipocytokine, is elevated in obesity and has been shown to alter ventilatory responses to exercise. Leptin’s bioavailability appears to be regulated by its soluble receptor (LRe), which is reduced in obesity. Roux-en-Y gastric bypass surgery (RYGBS) is a weight loss intervention that reduces total fat mass and improves several obesity related co-morbidities including pulmonary dysfunction. The purpose of this study was to first evaluate the differences between ventilatory responses to carbon dioxide (VE/VCO2 slope) during progressive treadmill walking in morbidly obese and normal weight females. Second, we will analyze the relationships between the VE/VCO2 slope, truncal adiposity, serum leptin, and LRe. Lastly, we want to evaluate the changes in the ventilatory responses to exercise (VE/VCO2 slope), truncal adiposity, serum leptin, and LRe 3 months following Roux-en Y gastric bypass surgery. Thirteen obese (OB 37.7 ±11.4 years, 42.0 ± 4.8 kg/m2) and 12 normal weight females (NW 36.1 ±8.0 years, 22.8 ± 1.2 kg/m2) participated in this study. Blood samples for measure of fasting serum leptin and soluble leptin receptor were obtained prior to exercise. Cardiopulmonary variables were measured throughout exercise. Regional adiposity was determined through dual energy x-ray absorptiometry. Truncal adiposity was significantly greater in the obese group than the normal weight group. Serum leptin was greater in the obese group while LRe was lower than the normal weight group. The VE/VCO2 slopes were lower in obese group when compared to the normal weight group. There were no significant group differences in maximal ventilation, tidal volume or respiratory rate. Stepwise regression determined that truncal adiposity accounted for 31.5% of variance in VE/VCO2 slope (R= 0.561, R2 =0.315, p = 0.004). At 3 months post-surgery we observed significant reductions in the obese group in total percentages of fat, truncal adiposity, serum leptin. The soluble leptin receptor was not changed at any measured time point following RYGBS. There were no changes in 3 months post-surgery VE/VCO2 slopes in the obese group. Truncal adiposity, serum leptin and LRe were associated with reduced ventilatory responses to weight bearing exercise (VE/VCO2 slope) in obese females when compared to normal weight females. There were no differences between obese and normal weight females in maximal minute ventilation, tidal volume or respiratory rate. This result suggests that differences in VE/VCO2 slopes may not be entirely from maximal pulmonary capacity. Rather, the differences in VE/VCO2 slope may be attributed to truncal adiposity and its positive relationship with leptin. Elevated leptin in the obese group may indicate a state of central leptin resistance which has been shown to reduce the ventilatory responses to exercise. At 3 months post RYGBS significant reductions in total percent fat, serum leptin, truncal adiposity and BMI were observed. However, despite improvement in fat mass and serum leptin there were no changes in the VE/VCO2 slope and LRe at 3 months post RYGBS. Therefore, it is possible that the improvements in body composition and leptin following RYGBS were not sufficient to increase ventilation responses to weight bearing exercise in obese females.