Brain protection in aortic arch surgery

Abstract Retrograde cerebral perfusion (RCP) techniques have been adopted in aortic arch surgery for clinical use. The clear benefits of RCP are that it reduces embolic injury and prolongs the permissible period of hypothermic circulatory arrest (HCA). At the same time, however, there is a great deal of evidence according to which RCP may be associated with an increased risk of fluid sequestration and cerebral edema. In the current study intermittent RCP was compared with continuous RCP and HCA alone to clarify if periodical RCP decreases fluid sequestration (I). HCA is an effective method of cerebral protection, but is associated with long cardiopulmonary bypass times, and coagulation disturbances. We tested the hypothesis that deep hypothermic RCP could improve cerebral outcome during moderate HCA (II and III). Glutamate excitotoxicity plays an important role in the development of ischemic brain injury. The purpose of the present study was to determine the efficacy of lamotrigine, a Na+ channel blocker, to mitigate cerebral injury after HCA (IV). A chronic porcine model was used in the present series of studies. Hemodynamic, electrophysiologic, and metabolic monitoring were performed until four hours after the instigation of rewarming. S-100β was measured up to 20 hours. Daily behavioral assessment performed until death or elective sacrifice on the seventh postoperative day. After continuous RCP the median fluid sequestration volume was 145 (0–250) ml compared with -50 (-100 - 0) ml after intermittent RCP (p = 0.04). In comparison of 15°C RCP to HCA alone during moderate 25°C hypothermia, 5/6 animals in the RCP group survived seven days compared with 2/6 in the HCA group (p = 0.04). The total histopathologic scores in the RCP(15°C) group were lower than those for the RCP(25°C) group during moderate 25°C hypothermia (p = 0.04). EEG bursts were recovered better in the RCP(15°C) group at 3 hours after the start of rewarming compared to HCA group (p = 0.05). The rate of EEG burst recovery was higher in lamotrigine treated animals compared to placebo treated animals after 4 hours during the rewarming (p = 0.02). Among the animals that survived for 7 days, the median behavioral score was higher in the lamotrigine group (8) compared with controls (7) (p = 0.02). The results indicate that intermittent RCP decreases the rate of fluid sequestration after continuous RCP. The cold RCP at moderate systemic hypothermia seems to provide a better neurological outcome than that with moderate temperature RCP, a finding suggesting that enhanced cranial hypothermia is the major beneficial factor of RCP. The Na+ channel blocker lamotrigine improves neurological outcome after a prolonged period of HCA. In conclusion, two refinements in the RCP concept are to administer it at low temperatures and if longer periods of perfusion are necessary, RCP should be applied intermittently

Spinal cord injury during selective cerebral perfusion and segmental artery occlusion:an experimental study

Abstract Objectives: Since selective cerebral perfusion (SCP) has been used in aortic arch surgical procedures, the core temperature during lower body circulatory arrest (LBCA) has been steadily rising. Simultaneously, the use of a frozen elephant trunk (FET) graft has been increasing. The safe period of LBCA in relation to spinal cord ischaemic tolerance in combination with segmental artery occlusion by the FET procedure has not been defined. Methods: Sixteen pigs were assigned to undergo 65 (n = 10) or 90 min (n  = 6) of SCP at 28°C with LBCA in combination with occlusion of the 8 uppermost segmental arteries in the thoracic (Th) aorta (15–20 cm FET, Th8-level). The follow-up period consisted of a 6-h intensive period and a 5-day observation period. Near-infrared spectroscopy of the collateral network was used to determine spinal cord oxygenation. The neurological status of the patients was evaluated daily, and the brain and the spinal cord were harvested for a histopathological analysis. Results: Five out of 6 pigs after 90 min and 1 out of 10 pigs after 65 min of LBCA died within 48 h of multiorgan failure. Of the survivors in the 65-min group, 6 out of 9 had paraparesis/paraplegia; the remaining 3 reached normal function. The lone survivor after 90 min of LBCA was paraplegic. Nadir near-infrared spectroscopy of the collateral network values at Th8 and Th10 were 34 (±5) and 39 (±4), and they were reached within 35 min of SCP in both groups. Conclusions: An extended FET graft with LBCA and SCP durations >65 min at 28°C results in a poor outcome

Control angiography for perioperative myocardial Ischemia after coronary surgery:meta-analysis

Abstract Background: Perioperative myocardial ischemia (PMI) in patients undergoing coronary artery bypass grafting (CABG) is associated with poor outcome. The aim of this study was to pool the available data on the outcome after control angiography and repeat revascularization in patients with perioperative myocardial ischemia (PMI) after coronary artery bypass grafting (CABG). Methods: A literature review was performed through PubMed, Scopus, ScienceDirect and Google Scholar to identify studies published since 1990 evaluating the outcome of PMI after CABG. Results: Nine studies included 1104 patients with PMI after CABG and 1056 of them underwent control angiography early after CABG. Pooled early mortality after reoperation for PMI without control angiography was 43.6% (95%CI 29.7–57.6%) and 79.8% of them (95%CI 64.4–95.2%) had an acute graft failure detected at reoperation. Among patients who underwent control angiography for PMI, 31.7% had a negative finding at angiography (95%CI 25.6–37.8%) and 62.1% had an acute graft failure (95%CI 56.6–67.6%). Repeat revascularization was performed after early control angiography in 46.3% of patients (95%CI 39.9–52.6%; 54.2% underwent repeat surgical revascularization; 45.8% underwent percutaneous coronary intervention). Pooled early mortality after control angiography with or without repeat revascularization was 8.9% (95%CI 6.7–11.1%). Three studies reported on early mortality rates which did not differ between repeat surgical revascularization and PCI (11.7% vs. 9.2%, respectively; risk ratio 1.45, 95%CI 0.67–3.11). In these three series, early mortality after conservative treatment was 5.9% (95%CI 3.6–8.2%). Conclusions: Control angiography seems to be a valid life-saving strategy to guide repeat revascularization in hemodynamically stable patients suffering PMI after CABG

Remote ischemic preconditioning and hypoxia-induced biomarkers in acute myocardial infarction:study on a porcine model

Abstract Objectives: Remote ischemic preconditioning (RIPC) mitigates acute myocardial infarction (AMI). We hypothesized that RIPC reduces the size and severity of AMI and explored molecular mechanisms behind this phenomenon. Design: In two series of experiments, piglets underwent 60 min of the circumflex coronary artery occlusion, resulting in AMI. Piglets were randomly assigned into the RIPC groups (n = 7 + 7) and the control groups (n = 7 + 7). The RIPC groups underwent four 5-min hind limb ischemia-reperfusion cycles before AMI. In series I, the protective efficacy of RIPC was investigated by using biomarkers and echocardiography with a follow-up of 24 h. In series II, the heart of each piglet was harvested for TTC-staining to measure infarct size. Muscle biopsies were collected from the hind limb to explore molecular mechanisms of RIPC using qPCR and Western blot analysis. Results: The levels of CK-MBm (p = 0.032) and TnI (p = 0.007) were lower in the RIPC group. Left ventricular ejection fraction in the RIPC group was greater at the end of the follow-up. The myocardial infarct size in the RIPC group was smaller (p = 0.033). Western blot indicated HIF1α stabilization in the skeletal muscle of the RIPC group. PCR analyses showed upregulation of the HIF target mRNAs for glucose transporter (GLUT1), glucose transporter 4 (GLUT4), phosphofructokinase 1 (PFK1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), enolase 1 (ENO1), lactate dehydrogenase (LDHA) and endothelial nitric oxidate synthase (eNOS). Conclusions. Biochemical, physiologic, and histologic evidence confirms that RIPC decreases the size of AMI. The HIF pathway is likely involved in the mechanism of the RIPC

Transfusion and blood stream infections after coronary surgery

Abstract The aim of this study was to evaluate the impact of blood transfusion on bloodstream infections. This study included 2764 patients who underwent isolated coronary artery bypass grafting. Blood cultures were drawn in 27.9% of patients and were positive in 3.5% of them. Blood transfusion before blood cultures were drawn (4.7% vs 1.2%, odds ratio 3.75, 95% confidence interval 1.11–12.67) and deep sternal wound infection/mediastinitis (20.0% vs 2.8%, odds ratio 7.43, 95% confidence interval 2.72–20.32) were independent predictors of a positive postoperative blood culture. Positive blood culture increased the risk of 5-year mortality (among patients with blood cultures drawn: 44.7% vs 19.6%, adjusted hazard ratio 2.10, 95% confidence interval 1.18–3.71). Exposure to blood products may increase the risk of bloodstream infection after cardiac surgery. Positive blood cultures after coronary artery bypass grafting are associated with poor late survival. These findings require validation in prospective studies

Meta-analysis of the sources of bleeding after adult cardiac surgery

Abstract Objective: The aim of this study was to pool data on the proportion and prognostic impact of sources of bleeding in patients requiring re-exploration after adult cardiac surgery. Design: Systematic review of the literature and meta-analysis. Setting: Multistitutional study. Measurements and Main Results: A literature review was performed to identify studies published since 1990 evaluating the outcome after reoperation for bleeding or tamponade after adult cardiac surgery. Eighteen studies including 5,1497 patients fulfilled the selection criteria. Reoperation for bleeding/tamponade was performed in 2,455 patients (4.6%; 95% confidence interval [CI] 3.9%–5.2%, I² 92%). These had a significantly higher risk of in-hospital/30-day mortality compared with patients not reoperated for bleeding (pooled rates: 9.3% v 2.3%; risk ratio 3.30; 95% CI 2.52–4.32; I² 47%; 8 studies; 25,463 patients). Surgical sites of bleeding were identified in 65.7% of cases (95% CI 58.3%–73.2%; I² 94%), cardiac site bleeding in 40.9% of cases (95% CI 29.7%–52.0%; I² 94%), and mediastinal/sternum site bleeding in 27.0% of cases (95% CI 16.8%–37.3%; I² 94%). The main sites of bleeding were the body of the graft (20.2%), the sternum (17.0%), vascular sutures (12.5%), the internal mammary artery harvest site (13.0%), and anastomoses (9.9%). In metaregression, surgical site bleeding was associated with a lower risk of in-hospital/30-day mortality compared with diffuse bleeding (p = 0.003). Conclusions: Surgical site bleeding is identified in two-thirds of patients undergoing re-exploration after adult cardiac surgery. Meticulous surgical technique and systematic intraoperative checking of potential surgical sites of bleeding at the time of the original cardiac surgery may reduce the risk of such a severe complication

Kalankasvatuksen ympärille rakennettava yritysekosysteemi:SIBE-projektin tapaustutkimus

Tiivistelmä Kotimaisen kalatuotannon kauppatase on 400 miljoonaa euroa miinuksella. Kalan lisäksi vihanneksia, kasviksia, hedelmiä, marjoja ja sieniä tuodaan maahan merkittäviä määriä. Tuonnin arvo pelkästään vihanneksissa ja kasviksissa on lähes 200 miljoonaa euroa vuodessa. Lähellä tuotetulle kotimaiselle ruoalle on suuri kysyntä, jota vahvistavat entisestään uudet ruokatrendit. Perinteinen suomalainen alkutuotanto kärsii myös kannattavuusongelmista ja on osittain liian kapea-alaista. Kotimaisen ruoantuotannon kilpailukykyä voidaan parantaa mm. hyödyntämällä kiertotaloudellisia ratkaisuja ja puhtaita teknologioita sekä tehdä asioita tehokkaammin yhteistyössä koko arvoverkon eri toimijoiden kanssa. Hankkeen lähtökohtana oli Laitakarin Kala Oy:n suunnitelmat Oulusta 20 kilometriä pohjoiseen Haukiputaan Martinniemeen sijoitettavasta suuresta kalankasvattamosta. Tavanomaisen kalankasvattamon rakentamisen lisäksi hankkeessa tarkasteltiin mahdollisuuksia saada kalankasvatuksen rinnalle muita liiketoimintoja, jotka tukisivat toisiaan. Hankkeen lopputuloksena syntyi konsepti sini-sen biotalouden liiketoimintaekosysteemistä, sen arvoketjuista ja toimijoista sekä arviot materiaali- ja energiavirroista. Konseptia työstettiin hankkeen aikana yhteistyössä ekosysteemin potentiaalisten toimijoiden kanssa haastatteluissa sekä yhteisessä työpajatilaisuudessa. Hankkeen aikana osa mietityistä innovatiivisista ratkaisuista osoittautui vielä taloudellisesti kannattamattomiksi ja osasta saatavat hyödyt ovat perinteisiin ratkaisuihin verrattuna niin marginaalisia, että niitä ei ainakaan tällä hetkellä kannata lähteä toteuttamaan. Kasvihuoneviljelyn kohdalla suurimmaksi haasteeksi muodostui liiketoiminnasta kiinnostuneen yrittäjän löytäminen. Kalan ja kasvien tuotannon yhdistämisellä saatavat synergiaedut näyttävät olevan melko marginaalisia johtuen kummankin prosessin kannalta tehtävistä kompromisseista. Kohteeksi valittu kurkun ympärivuotinen kasvihuoneviljely on lisäksi niin energiaintensiivistä, ettei suljetun kierron ratkaisuilla konseptin sisällä kasvihuoneen energiantarpeen täyttäminen ole mahdollista. Vaikka osa suunnitelluista ratkaisuista vaikuttaa esiselvityksen perusteella olevan kannattamattomia tai symbioosietujen olevan ennakoitua pienemmät, ovat ne tuloksina silti arvokkaita ja voivat säästää yrittäjiä turhalta yrityksen ja erehdyksen kautta tapahtuvalta toiminnalta. Lisäksi tulokset osoittavat suuntaa aihepiirin tarvitsemalle T&K-toiminnalle

Permanent work disability in patients ≤50 years old after percutaneous coronary intervention and coronary artery bypass grafting (the CRAGS study)

Abstract Background: The aim of this study was to investigate the incidence of permanent working disability (PWD) in young patients after percutaneous or surgical coronary revascularization. Methods and Results: The study included 1035 consecutive patients ≤50 years old who underwent coronary revascularization [910 and 125 patients in percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) groups, respectively] between 2002 and 2012 at 4 Finnish hospitals. The median follow-up time was 41 months. The overall incidence of PWD was higher after CABG compared to PCI (at 5 years, 34.8 vs. 14.7%, P < 0.001). Freedom from PWD in the general population aged 45 was 97.2% at 4 years follow-up. Median time to grant disability pension was 11.6 months after CABG and 24.4 months after PCI (P = 0.018). Reasons for PWD were classified as cardiac (35.3 vs. 36.9%), psychiatric (14.7 vs. 14.6%), and musculoskeletal (14.7 vs. 15.5%) in patients undergoing CABG vs. PCI. Overall freedom from PWD was higher in patients without major adverse cardiac and cerebrovascular event (MACCE) (at 5 years, 85.6 vs. 71.9%, P < 0.001). Nevertheless, rate of PWD was high also in patients without MACCE and patients with preserved ejection fraction during follow-up. Conclusions: Although coronary revascularization confers good overall survival in young patients, PWD is common especially after CABG and mostly for cardiac reasons even without occurrence of MACCE. Supportive measures to preserve occupational health are warranted concomitantly with coronary revascularization at all levels of health care

Perioperative bleeding requiring blood transfusions is associated with increased risk of stroke after transcatheter and surgical aortic valve replacement

Abstract Objectives: The authors aimed to investigate the impact of severe bleeding and use of red blood cell (RBC) transfusion on the development of postoperative stroke after surgical (SAVR) and transcatheter aortic valve replacement (TAVR), taken from the FinnValve registry. Design: Nationwide, retrospective observational study. Setting: Five Finnish university hospitals participated in the registry. Participants: A total of 6,463 patients who underwent SAVR (n = 4,333) or TAVR (n = 2,130). Interventions: Patients who underwent TAVR or SAVR with a bioprosthesis with or without coronary revascularization. Measurements and Main Results: The incidence of postoperative stroke after SAVR was 3.8%. In multivariate analysis, the number of transfused RBC units (odds ratio [OR], 1.098; 95% confidence interval [CI], 1.064–1.133) was one of the independent predictors of postoperative stroke. The incidence of stroke increased, along with the severity of perioperative bleeding, according to the European Coronary Artery Bypass Grafting (E-CABG) bleeding grades were as follows: grade 0, 2.2% (reference group); grade 1, 3.4% (adjusted OR, 1.841; 95% CI, 1.105–3.066); grade 2, 5.5% (adjusted OR, 3.282; 95% CI, 1.948–5.529); and grade 3, 14.8% (adjusted OR, 7.103; 95% CI, 3.612–13.966). The incidence of postoperative stroke after TAVR was 2.5%. The number of transfused RBC units was an independent predictor of stroke after TAVR (adjusted OR, 1.155; 95% CI, 1.058–1.261). The incidence of postoperative stroke increased, along with the severity of perioperative bleeding, as stratified by the E-CABG bleeding grades: E-CABG grade 0, 1.7%; grade 1, 5.3% (adjusted OR, 1.270; 95% CI, 0.532–3.035); grade 2, 10.0% (adjusted OR, 2.898; 95% CI, 1.101–7.627); and grade 3, 30.0% (adjusted OR, 10.706; 95% CI, 2.389–47.987). Conclusions: Perioperative bleeding requiring RBC transfusion and/or reoperation for intrathoracic bleeding is associated with an increased risk of postoperative stroke after SAVR and TAVR. Patient blood management and meticulous preprocedural planning and operative technique aiming to avoid significant perioperative bleeding may reduce the risk of cerebrovascular complications

Comparison of outcomes after transcatheter aortic valve replacement vs surgical aortic valve replacement among patients with aortic stenosis at low operative risk

Abstract Importance: Transcatheter aortic valve replacement (TAVR) has been shown to be a valid alternative to surgical aortic valve replacement (SAVR) in patients at high operative risk with severe aortic stenosis (AS). However, the evidence of the benefits and harms of TAVR in patients at low operative risk is still scarce. Objective: To compare the short-term and midterm outcomes after TAVR and SAVR in low-risk patients with AS. Design, Setting, and Participants: This retrospective comparative effectiveness cohort study used data from the Nationwide Finnish Registry of Transcatheter and Surgical Aortic Valve Replacement for Aortic Valve Stenosis of patients at low operative risk who underwent TAVR or SAVR with a bioprosthesis for severe AS from January 1, 2008, to November 30, 2017. Low operative risk was defined as a Society of Thoracic Surgeons Predicted Risk of Mortality score less than 3% without other comorbidities of clinical relevance. One-to-one propensity score matching was performed to adjust for baseline covariates between the TAVR and SAVR cohorts. Exposures: Primary TAVR or SAVR with a bioprosthesis for AS with or without associated coronary revascularization. Main Outcomes and Measures: The primary outcomes were 30-day and 3-year survival. Results: Overall, 2841 patients (mean [SD] age, 74.0 [6.2] years; 1560 [54.9%] men) fulfilled the inclusion criteria and were included in the analysis; TAVR was performed in 325 patients and SAVR in 2516 patients. Propensity score matching produced 304 pairs with similar baseline characteristics. Third-generation devices were used in 263 patients (86.5%) who underwent TAVR. Among these matched pairs, 30-day mortality was 1.3% after TAVR and 3.6% after SAVR (P = .12). Three-year survival was similar in the study cohorts (TAVR, 85.7%; SAVR, 87.7%; P = .45). Interaction tests found no differences in terms of 3-year survival between the study cohorts in patients younger than vs older than 80 years or in patients who received recent aortic valve prostheses vs those who did not. Conclusions and Relevance: Transcatheter aortic valve replacement using mostly third-generation devices achieved similar short- and mid-term survival compared with SAVR in low-risk patients. Further studies are needed to assess the long-term durability of TAVR prostheses before extending their use to low-risk patients