Early Onset of Postoperative Gastrointestinal Dysfunction Is Associated With Unfavorable Outcome in Cardiac Surgery: A Prospective Observational Study.

OBJECTIVE: The distribution of postoperative gastrointestinal (GI) dysfunction and its association with outcome were investigated in cardiac surgery patients. Gastrointestinal function was evaluated using the Acute Gastrointestinal Injury (AGI) grade proposed by the European Society of Intensive Care Medicine. DESIGN: Prospective observational study at a single center. SETTING: University hospital. PATIENTS: Consecutive patients presenting for elective cardiac surgery with extracorporeal circulation (ECC). INTERVENTIONS: None. RESULTS: Daily assessment using the AGI grade was performed on the first 3 postoperative days in addition to standard care. For analysis, 3 groups were formed based on the maximum AGI grade: AGI 0, AGI 1, and AGI ≥2. Five hundred and one patients completed the study; 32.7%, 65.1%, and 2.2% of the patients scored a maximum AGI 0, AGI 1, and AGI ≥2, respectively. Patients with AGI grade ≥2 had more frequently undergone thoracic aortic surgery and had longer surgery duration and time on ECC. Patients with AGI grade ≥2 had statistically significant higher frequency of GI complications within 30 days (63.6% vs 1.2% and 5.5% in patients with AGI 0 and AGI 1) and higher 30-day mortality (9.1% vs 0.0% and 1.8% in patients with AGI 0 and AGI 1). CONCLUSIONS: Early GI dysfunction following cardiac surgery was associated with an unfavorable outcome. Increased attention to GI dysfunction in cardiac surgery patients is warranted and the AGI grade could be a helpful adjunct to a structured approach.

Intestinal fatty acid-binding protein and acute gastrointestinal injury grade in postoperative cardiac surgery patients.

BACKGROUND AND AIM: Gastrointestinal complications post cardiac surgery are infrequent but difficult to diagnose and carry a high mortality. Plasma intestinal fatty acid-binding protein (I-FABP) concentrations and the relationship between I-FABP, gastrointestinal dysfunction, and postoperative outcomes were investigated in patients who developed gastrointestinal dysfunction (acute gastrointestinal injury [AGI] grade ≥2) and those with normal gastrointestinal function. METHODS: Patients with (AGI 2 group, n = 11) and without (matched controls, AGI 0 group, n = 22) early postoperative gastrointestinal dysfunction were extracted from a larger single-center prospective observational study, including adults undergoing elective cardiac surgery with extracorporeal circulation, and investigated in this nested case-control analysis. RESULTS: Both groups displayed variations in I-FABP concentrations with higher I-FABP on postoperative Day 1 compared to baseline and postoperative Days 2 and 3 (p < .001 and p = .005, respectively). The AGI 2 group had higher I-FABP concentrations on Day 2 compared to the AGI 0 group (p = .024). I-FABP on Day 2 correlated positively with AGI grade over the first 3 days (p = .036, p = .021 and p = .018, respectively). High I-FABP (defined as fourth quartile concentrations) on Day 1 was associated with more prolonged surgical procedures (p < .05). Furthermore, fourth quartile I-FABP on Day 1 and early gastrointestinal dysfunction were associated with higher frequencies of postoperative organ dysfunction (p < .05) and gastrointestinal complications (p < .05), and higher 365-day mortality. CONCLUSION: The present study indicates an association between intraoperative gastrointestinal injury, postoperative gastrointestinal dysfunction and gastrointestinal complications. A high-powered study is needed to further explore this relationship and the interpretation of I-FABP concentrations in individual cardiac surgery patients.

Assessment of Global Lung Function Initiative (GLI) reference equations for diffusing capacity in relation to respiratory burden in the Swedish CArdioPulmonary bioImage Study (SCAPIS).

The Global Lung Function Initiative (GLI) has recently published international reference values for diffusing capacity of the lung for carbon monoxide (D LCO). Lower limit of normal (LLN), i.e. the 5th percentile, usually defines impaired D LCO We examined if the GLI LLN for D LCO differs from the LLN in a Swedish population of healthy, never-smoking individuals and how any such differences affect identification of subjects with respiratory burden.Spirometry, D LCO, chest high-resolution computed tomography (HRCT) and questionnaires were obtained from the first 15 040 participants, aged 50-64 years, of the Swedish CArdioPulmonary bioImage Study (SCAPIS). Both GLI reference values and the lambda-mu-sigma (LMS) method were used to define the LLN in asymptomatic never-smokers without respiratory disease (n=4903, of which 2329 were women).Both the median and LLN for D LCO from SCAPIS were above the median and LLN from the GLI (p<0.05). The prevalence of D LCO GLI LLN but GLI LLN but GLI LLN and >SCAPIS LLN). No differences were found with regard to physician-diagnosed asthma.The GLI LLN for D LCO is lower than the estimated LLN in healthy, never-smoking, middle-aged Swedish adults. Individuals with D LCO above the GLI LLN but below the SCAPIS LLN had, to a larger extent, an increased respiratory burden. This suggests clinical implications for choosing an adequate LLN for studied populations.

Total resuscitative endovascular balloon occlusion of the aorta causes inflammatory activation and organ damage within 30 minutes of occlusion in normovolemic pigs.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) causes physiological, metabolic, end-organ and inflammatory changes that need to be addressed for better management of severely injured patients. The aim of this study was to investigate occlusion time-dependent metabolic, end-organ and inflammatory effects of total REBOA in Zone I in a normovolemic animal model. METHODS: Twenty-four pigs (25-35 kg) were randomized to total occlusion REBOA in Zone I for either 15, 30, 60 min (REBOA15, REBOA30, and REBOA60, respectively) or to a control group, followed by 3-h reperfusion. Hemodynamic variables, metabolic and inflammatory response, intraperitoneal and intrahepatic microdialysis, and plasma markers of end-organ injuries were measured during intervention and reperfusion. Intestinal histopathology was performed. RESULTS: Mean arterial pressure and cardiac output increased significantly in all REBOA groups during occlusion and blood flow in the superior mesenteric artery and urinary production subsided during intervention. Metabolic acidosis with increased intraperitoneal and intrahepatic concentrations of lactate and glycerol was most pronounced in REBOA30 and REBOA60 during reperfusion and did not normalize at the end of reperfusion in REBOA60. Inflammatory response showed a significant and persistent increase of pro- and anti-inflammatory cytokines during reperfusion in REBOA30 and was most pronounced in REBOA60. Plasma concentrations of liver, kidney, pancreatic and skeletal muscle enzymes were significantly increased at the end of reperfusion in REBOA30 and REBOA60. Significant intestinal mucosal damage was present in REBOA30 and REBOA60. CONCLUSION: Total REBOA caused severe systemic and intra-abdominal metabolic disturbances, organ damage and inflammatory activation already at 30 min of occlusion.

Results of postoperative microdialysis intraperitoneal and at the anastomosis in patients developing anastomotic leakage after rectal cancer surgery.

Introduction: Anastomotic leakage postoperatively in patients operated with rectum resection and primary anastomosis is a common and feared complication. We have studied seven patients with an anastomotic leakage after surgery and compared them with 13 patients without complications.Methods: Metabolic measurements with microdialysis were done during the first seven postoperative days, with measurements of glucose, pyruvate, lactate and glycerol. The lactate/pyruvate ratio was calculated. Measurements were performed subcutaneously, intraperitoneally and at the anastomosis. The inflammatory cytokines, IL 6 and IL 10, were measured intravenously and intraperitoneally 48 hours postoperatively.Results: Intravenous and intraperitoneal IL 6 were higher in the leakage group. Around the small intestine (intraperitoneally), we found that patients developing anastomotic leakage had higher lactate and lactate/pyruvate ratio immediately after surgery. They also showed lower glycerol levels. At the anastomosis, we found higher lactate and lactate/pyruvate ratio in anastomotic leak patients after the fourth postoperative day.Conclusions: The results indicate that a possible mechanism behind an anastomotic leakage is an impaired circulation and thus insufficient saturation to the small intestine peroperatively. This develops into an inflammation both intraperitoneally and intravenously, which, if not reversed, spread within the gastrointestinal tract .The colorectal anastomosis is the most vulnerable part of the gastrointestinal tract postoperatively and hypoxia and inflammation may occur there, and an anastomosis leakage will be the consequence.

A comprehensive risk stratification at early follow-up determines prognosis in pulmonary arterial hypertension.

Aims: Guidelines recommend a goal-oriented treatment approach in pulmonary arterial hypertension (PAH). The aim is to reach a low-risk profile, as determined by a risk assessment instrument. This strategy is incompletely validated. We aimed to investigate the bearing of such risk assessment and the benefit of reaching a low-risk profile. Methods and results: Five hundred and thirty PAH patients were included. Follow-up assessments performed after a median of 4 (interquartile range 3-5) months were available for 383 subjects. Patients were classified as 'Low', 'Intermediate', or 'High risk' and the benefit of reaching the 'Low risk' group was estimated. Survival differed (P < 0.001) between the risk groups at baseline and at follow-up. Survival was similar for patients who remained in or improved to the 'Low risk' group. Survival was similar for patients who remained in or worsened to the 'Intermediate risk' or 'High risk' groups. Irrespective of follow-up risk group, survival was better (P < 0.001) for patients with a higher proportion of variables at low risk. Results were unchanged after excluding patients with idiopathic PAH >65 years at diagnosis, and when patients with idiopathic or connective tissue disease-associated PAH were analysed separately. Patients in the 'Low risk' group at follow-up exhibited a reduced mortality risk (hazard ratio 0.2, 95% confidence interval 0.1-0.4 in multivariable analysis adjusted for age, sex and PAH subset), as compared to patients in the 'Intermediate risk' or 'High risk' groups. Conclusion: These findings suggest that comprehensive risk assessments and the aim of reaching a low-risk profile are valid in PAH.

Perioperative intraperitoneal metabolic markers in patients undergoing cardiac surgery with cardiopulmonary bypass: an exploratory pilot study.

BACKGROUND: Cardiopulmonary bypass and postoperative cardiac dysfunction cause splanchnic hypoperfusion resulting in intra-abdominal anaerobic metabolism and risk for gastrointestinal complications. The intra-abdominal metabolism can be monitored by intraperitoneal measurement of relevant metabolites using microdialysis. The aim of this study was to investigate the intraperitoneal metabolism using microdialysis during and after cardiopulmonary bypass at 34°C. METHODS: In six patients undergoing elective coronary artery bypass grafting or aortic valve replacement under cardiopulmonary bypass, microdialysis was used to measure intraperitoneal and subcutaneous glucose, lactate, pyruvate, glycerol and glutamate concentrations, intraoperatively and up to 36 hours postoperatively. Arterial and central venous blood gases were analysed as were haemodynamics and the development of complications. RESULTS: All patients had an ordinary perioperative course and did not develop gastrointestinal complications. The arterial, intraperitoneal and subcutaneous lactate concentrations changed during the perioperative course with differences between compartments. The highest median (interquartile range) concentration was recorded in the intraperitoneal compartment at 1 hour after the end of cardiopulmonary bypass (2.1 (1.9-2.5) mM compared to 1.3 (1.2-1.7) mM and 1.5 (1.0-2.2) mM in the arterial and subcutaneous compartments, respectively). In parallel with the peak increase in lactate concentration, the intraperitoneal lactate/pyruvate ratio was elevated to 33.4 (12.9-54.1). CONCLUSION: In cardiac surgery, intraperitoneal microdialysis detected changes in the abdominal metabolic state, which were more pronounced than could be shown by arterial blood gas analysis. Despite an uneventful perioperative course, patients undergoing low-risk surgery under cardiopulmonary bypass might be subjected to a limited and subclinical intra-abdominal anaerobic state.

Peritoneal microdialysis as a tool for detecting anastomotic leakage in patients after left-side colon and rectal resection. A systematic review.

OBJECTIVE: The objective was to evaluate peritoneal microdialysis in the detection of clinical anastomotic leakage after left-sided colon and rectal resection through a systematic review. METHODS: A systematic review (PRISMA guidelines) based on a systematic search through PubMed, Cochrane Library, and EMBASE (1 February 2017) was performed. Methodological index of non-randomised studies score was selected to assess the methodological quality. Patient demographics and raw data for intraperitoneal microdialysis concentrations of glucose, lactate, glycerol and pyruvate for 5 d postoperative were obtained from the respective study groups. RESULTS: Ten studies with a total of 128 patients were included. Thirty (23%) patients developed clinical anastomotic leakage. The area under the curve for intraperitoneal lactate concentration was significant higher in patients with anastomotic leakage (58.2; 95% CI 39.2, 77.2) compared with the no leakage group (41.0; 95% CI 35.2, 46.1; p = .007). Receiver operating characteristic curve analysis of the maximum measured lactate concentration demonstrated 25% sensitivity, 88% specificity and 74% accuracy for AL at a cut-off value of 9.8 mmol/L. The odds ratio for a 5 mmol/L increase in lactate in relation to the risk of AL was 2.9 (CI 1.1, 8.0). CONCLUSIONS: Increased intraperitoneal lactate concentration within the first 5 d postoperative was significantly associated with clinical anastomotic leakage, but with low predictive values. The microdialysis method is not yet ready for clinical implication before large prospective studies have defined cut off values for a biologic marker in the setting of a clear definitions of leakage.

Direct Synthesis of Two Inorganic Catalysts on Carbon Fibres for the Electrocatalytic Oxidation of Water.

Two electrodes for anodic water oxidation made by direct synthesis of inorganic catalysts onto conductive carbon fibre sheets are evaluated. As catalysts two Co- and Sb-containing phases were tested, that is, Co3 Sb4 O6 F6 and the new compound CoSbO4 . The compounds express large differences in their morphology: CoSbO4 grows as thin needles whereas Co3 Sb4 O6 F6 grows as larger facetted crystals. Despite the smaller surface area the latter compound shows a better catalytic performance. When the compound Co3 Sb4 O6 F6 was used it gave a low increase of +0.028 mV h-1 at an overpotential of η=472 mV after 10 h and a stability of +0.48 mV h-1 at an overpotential of η=488 mV after 60 h. The leakages of Co and Sb were negligible and only <0.001 at % Co and approximately 0.02 at % Sb were detected in the electrolyte.

Effect of everolimus vs calcineurin inhibitors on quality of life in heart transplant recipients during a 3-year follow-up: Results of a randomized controlled trial (SCHEDULE).

The Scandinavian heart transplant everolimus de novo study with early calcineurin inhibitors avoidance (SCHEDULE) trial was a 12 month, randomized, open-label, parallel-group trial that compared everolimus (EVR; n=56) to conventional CsA (n=59) immunosuppression. Previously, we reported that EVR outperformed CsA in improving renal function and coronary artery vasculopathy, despite a higher rejection rate with EVR. This study aimed to compare the effects of these treatments on quality of life (QoL). Within five post-operative days, patients (mean age 50±13 years, 27% women) were randomized to EVR or a standard CsA dosage (CsA group). This study assessed quality of life (QoL), based on the Short Form-36, EuroQol-5D, and Beck Depression Inventory (BDI). Assessments were performed pre-HTx and 12 and 36 months post-HTx. At 12 and 36 months, the groups showed similar improvements in Short Form-36 measures (at pre-HTx, 12 and 36 months the values were as follows: Physical component summary: EVR: 31.5±110.9, 49.1±9.7, and 47.9±10.6; P<.01; CsA: 32.5±8.2, 48.4±8.5, and 46.5±11.5; P<.01; mental component summary: EVR: 46.0±12.0, 51.7±11.9, and 52.1±13.0; P<.01; CsA: 38.2±12.5, 53.4±7.1, and 54.3±13.0; P<.01); similar decrease in mean BDI (EVR: 10.9±10.2, 5.4±4.7, and 8.1±9.0; P<.01; CsA: 11.8±7.1, 6.3±5.4, and 6.2±6.5; P<.01); and similar Euro Qol-improvements. Thus, in this small-sized study, EVR-based and conventional CsA immunosuppressive strategies produced similar QoL improvements.

Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review.

OBJECTIVES: Abdominal radiography is frequently used in acute abdominal non-traumatic pain despite the availability of more advanced diagnostic modalities. This study evaluates the diagnostic accuracy of low-dose CT compared with abdominal radiography, at similar radiation dose levels. METHODS: Fifty-eight patients were imaged with both methods and were reviewed independently by three radiologists. The reference standard was obtained from the diagnosis in medical records. Sensitivity and specificity were calculated. A systematic review was performed after a literature search, finding a total of six relevant studies including the present. RESULTS: Overall sensitivity with 95 % CI for CT was 75 % (66-83 %) and 46 % (37-56 %) for radiography. Specificity was 87 % (77-94 %) for both methods. In the systematic review the overall sensitivity for CT varied between 75 and 96 % with specificity from 83 to 95 % while the overall sensitivity for abdominal radiography varied between 30 and 77 % with specificity 75 to 88 %. CONCLUSIONS: Based on the current study and available evidence, low-dose CT has higher diagnostic accuracy than abdominal radiography and it should, where logistically possible, replace abdominal radiography in the workup of adult patients with acute non-traumatic abdominal pain. KEY POINTS: • Low-dose CT has a higher diagnostic accuracy than radiography. • A systematic review shows that CT has better diagnostic accuracy than radiography. • Radiography has no place in the workup of acute non-traumatic abdominal pain.

Long-term outcomes of thoracic transplant recipients following conversion to everolimus with reduced calcineurin inhibitor in a multicenter, open-label, randomized trial.

The NOCTET study randomized 282 patients ≥1 year after heart or lung transplantation to continue conventional calcineurin inhibitor (CNI) therapy or to start everolimus with reduced-exposure CNI. Last follow-up, at ≥5 years postrandomization (mean: 5.6 years) was attended by 72/140 everolimus patients (51.4%) and 91/142 controls (64.1%). Mean measured GFR remained stable in the everolimus group from randomization (51.3 ml/min) to last visit (51.4 ml/min) but decreased in controls (from 50.5 ml/min to 45.3 ml/min) and was significantly higher with everolimus at last follow-up (P = 0.004). The least squares mean (SE) change from randomization was -1.5 (1.7)ml/min with everolimus versus -7.2 (1.7)ml/min for controls (difference: 5.7 [95% CI 1.7; 9.6]ml/min; P = 0.006). The difference was accounted for by heart transplant patients (difference: 6.9 [95% 2.3; 11.5]ml/min; P = 0.004). Lung transplant patients showed no between-group difference at last follow-up. Rates of rejection, death, and major cardiac events were similar between groups, as was graft function. Pneumonia was more frequent with everolimus (18.3% vs. 6.4%). In conclusion, introducing everolimus in maintenance heart transplant patients, with reduced CNI, achieves a significant improvement in renal function which is maintained for at least 5 years, but an early renal benefit in lung transplant patients was lost. Long-term immunosuppressive efficacy was maintained.

Characteristics and survival of adult Swedish PAH and CTEPH patients 2000-2014.

OBJECTIVES: The Swedish Pulmonary Arterial Hypertension Register (SPAHR) is an open continuous register, including pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) patients from 2000 and onwards. We hereby launch the first data from SPAHR, defining baseline characteristics and survival of Swedish PAH and CTEPH patients. DESIGN: Incident PAH and CTEPH patients 2008-2014 from all seven Swedish PAH-centres were specifically reviewed. RESULTS: There were 457 PAH (median age: 67 years, 64% female) and 183 CTEPH (median age: 70 years, 50% female) patients, whereof 77 and 81%, respectively, were in functional class III-IV at diagnosis. Systemic hypertension, diabetes, ischaemic heart disease and atrial fibrillation were common comorbidities, particularly in those >65 years. One-, 3- and 5-year survival was 85%, 71% and 59% for PAH patients. Corresponding numbers for CTEPH patients with versus without pulmonary endarterectomy were 96%, 89% and 86% versus 91%, 75% and 69%, respectively. In 2014, the incidence of IPAH/HPAH, associated PAH and CTEPH was 5, 3 and 2 per million inhabitants and year, and the prevalence was 25, 24 and 19 per million inhabitants. CONCLUSION: The majority of the PAH and CTEPH patients were diagnosed at age >65 years, in functional class III-IV, and exhibiting several comorbidities. PAH survival in SPAHR was similar to other registers.

Intra-abdominal hypertension--an experimental study of early effects on intra-abdominal metabolism.

BACKGROUND: The main aim of this experimental study was to investigate the early effects of intra-abdominal hypertension (IAH) on intra-abdominal metabolism and intestinal mucosal blood flow to evaluate whether metabolites can serve as markers for organ dysfunction during IAH. METHODS: A swine model was used, and the animals were anesthetized and ventilated. Fifteen animals were subjected to IAH of 30 mm Hg for 4 hr by carbon dioxide insufflation. Seven animals served as controls. Hemodynamic data, arterial blood samples, and urine output were analyzed. Intraluminal laser Doppler flowmetry measured intestinal mucosal blood flow. Glucose, glycerol, lactate, and pyruvate concentrations and lactate-to-pyruvate (l/p) ratio were measured intraperitoneally and intramurally in the small intestine and rectum using microdialysis. RESULTS: IAH lowered the abdominal perfusion pressure by 12-18 mm Hg, reduced the intestinal mucosal blood flow by 45-63%, and decreased urine output by 50-80%. In the intervention group, glycerol concentrations increased at all locations, pyruvate concentrations decreased, and the l/p ratio increased intraperitoneally and intramurally in the small intestine. Control animals remained metabolically stable. Glucose and lactate concentrations were only slightly affected or unchanged in both the groups. CONCLUSIONS: IAH reduces intestinal blood flow and urinary output and causes early metabolic changes, indicating a discrete shift toward anaerobic metabolism. Intraperitoneal microdialysis may be useful in the early detection of impaired organ dysfunction with metabolic consequences in IAH and abdominal compartment syndrome.

Intraperitoneal metabolic consequences of supraceliac aortic balloon occlusion in an experimental animal study using microdialysis.

BACKGROUND: To investigate the effects of supraceliac aortic balloon occlusion (ABO) and superior mesenteric artery (SMA) occlusion on abdominal visceral metabolism in an animal model using intraperitoneal microdialysis (IPM) and laser Doppler flowmetry. METHODS: A total of 9 pigs were subjected to ABO and 7 animals were subjected to SMA occlusion for 1 hour followed by 3 hours of reperfusion. Seven animals served as controls. Hemodynamic data, arterial blood samples, urinary output, and intestinal mucosal blood flow (IBF) were followed hourly. Intraperitoneal (i.p) glucose, glycerol, lactate, and pyruvate concentrations and lactate-to-pyruvate (l/p) ratio were measured using IPM. RESULTS: Compared with the baseline, ABO reduced IBF by 76% and decreased urinary output. SMA occlusion reduced IBF by 75% without affecting urinary output. ABO increased the i.p l/p ratio from 18 at baseline, peaking at 46 in early reperfusion. SMA occlusion and reperfusion tended to increase the i.p l/p ratio, peaking at 36 in early reperfusion. ABO increased the i.p glycerol concentration from 87 µM at baseline to 579 µM after 3 hours of reperfusion. SMA occlusion and reperfusion increased the i.p glycerol concentration but to a lesser degree. CONCLUSIONS: Supraceliac ABO caused severe hemodynamic, renal, and systemic metabolic disturbances compared with SMA occlusion, most likely because of the more extensive ischemia-reperfusion injury. The intra-abdominal metabolism, measured by microdialysis, was affected by both ABO and SMA occlusion but the most severe disturbances were caused by ABO. The i.p l/p ratios and the glycerol concentrations increased during ischemia and reperfusion and may serve as markers of these events and indicate anaerobic metabolism and cell damages respectively.

Photonic crystals with rainbow colors by centrifugation-assisted assembly of colloidal lignin nanoparticles.

Photonic crystals are optical materials that are often fabricated by assembly of particles into periodically arranged structures. However, assembly of lignin nanoparticles has been limited due to lacking methods and incomplete understanding of the interparticle forces and packing mechanisms. Here we show a centrifugation-assisted fabrication of photonic crystals with rainbow structural colors emitted from the structure covering the entire visible spectrum. Our results show that centrifugation is crucial for the formation of lignin photonic crystals, because assembly of lignin nanoparticles without centrifugation assistance leads to the formation of stripe patterns rather than photonic crystals. We further prove that the functions of centrifugation are to classify lignin nanoparticles according to their particle size and produce monodispersed particle layers that display gradient colors from red to violet. The different layers of lignin nanoparticles were assembled in a way that created semi-closed packing structures, which gave rise to coherent scattering. The diameter of the lignin nanoparticles in each color layer is smaller than that predicted by a modified Bragg's equation. In situ optical microscope images provided additional evidence on the importance of dynamic rearrangement of lignin nanoparticles during their assembly into semi-closed packing structures. The preparation of lignin nanoparticles combined with the methodology for their classification and assembly pave the way for sustainable photonic crystals.

Fully covered self-expandable metal stent placed over a stapled colon anastomosis in an animal model: A pilot study of colon metabolism over the stent.

Background and Aim: Anastomotic leakage (AL) in colorectal resection and primary anastomosis is a common and feared complication. Fully covered self-expandable metal stents (FCSEMSs) have been used for the treatment of AL. It is still unknown whether FCSEMSs affect anastomosis healing negatively by causing ischemia. In an animal study, we investigated the metabolic effects over a FCSEMS covering a stapled colon anastomosis. Methods: Seven pigs were investigated using microdialysis after laparotomy, colon resection, and anastomosis with stent placement. Measurements were done at the proximal and distal ends of the anastomosis and at a reference catheter placed at the small intestine. Measurements of glucose, pyruvate, lactate, glycerol, and the lactate/pyruvate ratio (L/P) were carried out. Results: Lactate and L/P were significantly higher at the oral part of the anastomosis, while glucose showed a small declining tendency. At the distal part of the anastomosis, glucose decreased significantly after the resection but did not reach zero. Lactate increased significantly whereas L/P increased only slightly. Glycerol levels were stable. Conclusion: Colon resection caused initially hypermetabolism in the intestinal ends next to the resection site. This hypermetabolism neither deteriorated nor turned into ischemia during the initial postoperative course, but the start of hypoxemia could not be excluded during the study and after the placement of an FCSEMS.

Altered mRNA Expression Due to Rectal Perforation in a Porcine Model - A Pilot Study.

BACKGROUND: Anastomotic leakage is the most serious and unwelcome complication in rectal surgery. It has a great impact on postoperative morbidity and mortality. In this pilot study, changes of mRNA expression in blood were analyzed in an animal model designed to imitate anastomotic leakage. MATERIALS AND METHODS: Twelve pigs were randomized into two groups: A sham-operated control group and an experimental group in which iatrogenic rectal perforation was performed. The changes in the mRNA expression at 4 hours after creating the perforation were studied. Microarray analysis was performed using Gene Chip whole porcine genome array. mRNA expression of 19,124 genes was investigated. RESULTS: Significantly increased levels of genes with a fold change greater than 2 were found, including 276 coding for unknown proteins and 48 coding for known proteins. Eleven of those which coded for known proteins were up-regulated with a fold change >4. CONCLUSION: Eleven known genes were highly up-regulated after rectal perforation. These genes were mainly involved in inflammatory response, intracellular signaling and cell membrane regulation. Their corresponding proteins might potentially be clinical biomarkers of anastomotic leakage and should be evaluated in further clinical studies.

Five year risk assessment and treatment patterns in patients with chronic thromboembolic pulmonary hypertension.

AIMS: Repeated risk assessments and treatment patterns over long time are sparsely studied in chronic thromboembolic pulmonary hypertension (CTEPH); thus, we aimed to investigate changes in risk status and treatment patterns in incident patients with CTEPH over a 5 year period. METHODS AND RESULTS: Descriptive and explorative study including 311 patients diagnosed with CTEPH 2008-2019 from the Swedish pulmonary hypertension registry, stratified by pulmonary endarterectomy surgery (PEA). Risk and PH-specific treatment were assessed in surgically treated (PEA) and medically treated (non-PEA) patients at diagnosis and up to 5 years follow-up. Data are presented as median (Q1-Q3), count or per cent. Prior to surgery, 63% in the PEA-group [n = 98, age 64 (51-71) years, 37% female] used PH-specific treatment and 20, 69, and 10% were assessed as low, intermediate or high risk, respectively. After 1 year post-surgery, 34% had no PH-specific treatment or follow-up visit registered despite being alive at 5 years. Of patients with a 5 year visit (n = 23), 46% were at low and 54% at intermediate risk, while 91% used PH-specific treatment. In the non-PEA group [n = 213, age 72 (65-77) years, 56% female], 28% were assessed as low, 61% as intermediate and 11% as high risk. All patients at high risk versus 50% at low risk used PH-specific treatment. The 1 year mortality was 6%, while the risk was unchanged in 57% of the patients; 14% improved from intermediate to low risk, and 1% from high to low risk. At 5 years, 27% had a registered visit and 28% had died. Of patients with a 5 year visit (n = 58), 38% were at low, 59% at intermediate and 1% at high risk, and 86% used PH-specific treatment. CONCLUSIONS: Risk status assessed pre-surgery did not foresee long-term post-PEA risk and pre-surgery PH-specific treatment did not foresee long-term post-PEA treatment. Medically treated CTEPH patients tend to remain at the same risk over time, suggesting a need for improved treatment strategies in this group.

Intraperitoneal glycerol levels and lactate/pyruvate ratio: early markers of postoperative complications.

OBJECTIVE: We have previously presented microdialysis findings of early intraperitoneal (i.p.) metabolic disturbances, mainly an increased lactate/pyruvate (l/p) ratio, in surgical patients developing postoperative complications. The aim of the present study was to investigate i.p. glycerol and l/p ratio after major surgery with and without complications. MATERIAL AND METHODS: Sixty patients were followed with microdialysis for 48 h after major abdominal surgery, 44 patients without postoperative complications and 16 patients with major surgical complications. Intraperitoneal and subcutaneous (s.c.) measurements of glycerol, lactate, pyruvate and glucose were performed, and the l/p ratio was calculated. RESULTS: Intraperitoneal glycerol was significantly lower in the complication group compared with the control group (64 vs. 94.6 µM; p = 0.0015), while the i.p. l/p ratio was significantly higher in the complication group compared with the control group (13.7 vs. 11.1; p = 0.0073). CONCLUSIONS: In this study, i.p. glycerol levels were lower and i.p. l/p ratio was higher in the immediate postoperative period in a group of patients with complications. These results might indicate early i.p. disturbances in fat and carbohydrate metabolism in patients who later developed symptoms of postoperative major complications.