Azide Photochemistry in Acrylic Copolymers for Ultraviolet Cross-Linkable Pressure-Sensitive Adhesives: Optimization, Debonding-on-Demand, and Chemical Modification.

Pressure-sensitive adhesives (PSAs) are usually made from viscoelastic, high-molecular-weight copolymers, which are fine-tuned by adjusting the comonomer ratios, molecular weights, and cross-link densities to optimize the adhesion properties for the desired end-use. To create a lightly cross-linked network, an ultraviolet (UV) photoinitiator can be incorporated. Here, we present the first use of perfluorophenylazide chemistry to control precisely a polyacrylate network for application as a PSA. Upon UV irradiation, the highly reactive nitrene from the azide moiety reacts with nearby molecules through a C-H insertion reaction, resulting in cross-linking via covalent bonding. This approach offers three benefits: (1) a means to optimize adhesive properties without the addition of an external photoinitiator; (2) the ability to switch off the tack adhesion on demand via a high cross-linking density; and (3) a platform for additional chemical modification. A series of poly(n-butyl acrylate-co-2,3,4,5,6-pentafluorobenzyl acrylate) or poly(PFBA-co-BA) copolymers were synthesized and modified post-polymerization into the photo-reactive poly(n-butyl acrylate-co-4-azido-2,3,5,6-tetrafluorobenzyl acrylate) [azide-modified poly(PFBA-co-BA)] with various molar contents. When cast into films, the azide-modified copolymers with a high azide content achieved a very high shear resistance after UV irradiation, whereas the tack and peel adhesion decreased strongly with the increase in azide content, indicating that excessive cross-linking occurred. These materials are thus photo-switchable. However, in the low range of azide content, an optimum probe tack adhesion energy was obtained in films with a 0.3 mol % azide content, where a long stress plateau (indicating good fibrillation) with a high plateau stress was observed. An optimum peel adhesion strength was achieved with 0.5 mol % azide. Thus, the adhesion was finely controlled by the degree of cross-linking of the PSA, as determined by the azide content of the copolymer chain. Finally, as a demonstration of the versatility and advantages of the material platform, we show an azide-aldehyde-amine multicomponent modification of the azide copolymer to make a dye-functionalized film that retains its adhesive properties. This first demonstration of using azide functionality has enormous potential for functional PSA design.

Biocompatibility and Physiological Thiolytic Degradability of Radically Made Thioester-Functional Copolymers: Opportunities for Drug Release.

Being nondegradable, vinyl polymers have limited biomedical applicability. Unfortunately, backbone esters incorporated through conventional radical ring-opening methods do not undergo appreciable abiotic hydrolysis under physiologically relevant conditions. Here, PEG acrylate and di(ethylene glycol) acrylamide-based copolymers containing backbone thioesters were prepared through the radical ring-opening copolymerization of the thionolactone dibenzo[c,e]oxepin-5(7H)-thione. The thioesters degraded fully in the presence of 10 mM cysteine at pH 7.4, with the mechanism presumed to involve an irreversible S-N switch. Degradations with N-acetylcysteine and glutathione were reversible through the thiol-thioester exchange polycondensation of R-SC(═O)-polymer-SH fragments with full degradation relying on an increased thiolate/thioester ratio. Treatment with 10 mM glutathione at pH 7.2 (mimicking intracellular conditions) triggered an insoluble-soluble switch of a temperature-responsive copolymer at 37 °C and the release of encapsulated Nile Red (as a drug model) from core-degradable diblock copolymer micelles. Copolymers and their cysteinolytic degradation products were found to be noncytotoxic, making thioester backbone-functional polymers promising for drug delivery applications.

Risk of perioperative coronary stent stenosis or occlusion in patients with previous percutaneous coronary intervention undergoing coronary artery bypass grafting surgery.

OBJECTIVES: There is an ongoing discussion about how to treat coronary stents during bypass surgery: Should patent stents be left alone and the stented vessels be ungrafted, or should every stented coronary artery receive a bypass graft? This study aims to determine the relevance of perioperative stent stenosis or occlusion on postoperative outcomes up to 3 years postoperatively. METHODS: Patients undergoing coronary artery bypass grafting surgery (CABG) (±concomitant procedures) with previous percutaneous coronary intervention from 4 centres were prospectively included in this observatory study between April 2015 and June 2017. A coronary angiography was conducted between the fifth and seventh postoperative days. The preoperative and postoperative angiograms were assessed in a core laboratory, assessing the patencies of coronary stents and bypass grafts. The core lab investigators were blinded to the patients' characteristics and perioperative course. RESULTS: A total of 107 patients were included in the study. In the postoperative coronary angiography, 265 bypass grafts and 189 coronary stents were examined angiographically. Ninety-seven percent of preoperatively patent stents remained patent. New coronary stent stenoses were observed in 5 patients (4.7%). All 5 patients were asymptomatic and managed conservatively. Bypass stenoses were observed in 12 patients (11%), of whom were managed conservatively, 4 underwent percutaneous coronary intervention and 1 underwent redo-CABG. Two years postoperatively, 97% of patients were alive. Patients with new stent stenosis tended to have a better survival compared with patients with bypass stenosis (100% vs 73%; P = 0.09) up to 3 years postoperatively. CONCLUSIONS: Perioperative coronary stent stenosis occurs rarely. It is safe to leave a patently stented coronary vessel without bypass grafting.

Predicting Cardiac Surgery-Associated Acute Kidney Injury Using a Combination of Clinical Risk Scores and Urinary Biomarkers.

BACKGROUND: Prediction, early diagnosis, and therapy of cardiac surgery-associated acute kidney injury (CSA-AKI) are challenging. We prospectively tested a staged approach to identify patients at high risk for CSA-AKI combining clinical risk stratification and early postoperative quantification of urinary biomarkers for AKI. METHODS: All patients, excluding those on chronic hemodialysis, undergoing scheduled surgery with cardiopulmonary bypass between August 2015 and July 2016 were included. First, patients were stratified by calculating the Cleveland clinic score (CCS) and the Leicester score (LS). In high-risk patients (defined as LS > 25 or CCS > 6), urinary concentrations of biomarkers for AKI ([TIMP-2]*[IGFBP-7]) were evaluated 4 hours postoperatively. CSA-AKI was observed until postoperative day 6 and classified using the Kidney Disease: Improving Global Outcomes criteria. RESULTS: AKI occurred in 352 of613 patients (54%). In high-risk patients, AKI occurred more frequently than in low-risk patients (66 vs. 49%; p = 0.001). In-hospital mortality after AKI stage 2 (15%) or AKI stage 3 (49%) compared with patients without AKI (1.8%; p = 0.001) was increased. LS was predictive for all stages of AKI (area under the curve [AUC] 0.601; p < 0.001) with a poor or fair accuracy, while CCS was only predictive for stage 2 or 3 AKI (AUC 0.669; p < 0.001) with fair accuracy. In 133 high-risk patients, urinary [TIMP-2]*[IGFBP-7] was significantly predictive for all-stage AKI within 24 hours postoperatively (AUC 0.63; p = 0.017). However, for the majority of AKI (55%), which occurred beyond 24 hours postoperatively, urinary [TIMP-2]*[IGFBP-7] was not significantly predictive. Sensitivity for all-stage AKI within 24 hours was 0.38 and specificity was 0.81 using a cutoff value of 0.3. CONCLUSION: CSA-AKI is a relevant and frequent complication after cardiac surgery. Patients at high risk for CSA-AKI can be identified using clinical prediction scores, however, with only poor to fair accuracy. Due to its weak test performance, urinary [TIMP-2]*[IGFBP-7] quantification 4 hours postoperatively does not add to the predictive value of clinical scores.

Fibrin-Coated Collagen Fleece Seems to Prevent Sternal Instability after Cardiac Surgery: A Matched Pair Data Analysis.

BACKGROUND: To examine if fibrin-coated collagen fleece (Tachosil) interferes with bone and wound healing when it is used on the cut surface of the sternum after median sternotomy. METHODS: A total of 25 patients with osteoporotic sternal disorders were treated with fibrin-coated collagen fleece at the cut surface of the sternum after median sternotomy (therapy group). We compared the occurrence of impaired wound healing and sternal instability, reoperation rate, and 30-day mortality with a control group of 25 case-matched patients. After matching for age, gender, and risk factors for sternal instability (diabetes mellitus, osteoporosis, body mass index, nicotine consumption), both groups were comparable. RESULTS: Sternal instability occurred in one (4%) patient in the study group and in five (20%) patients in the control group. Impaired wound healing occurred in one (4%) patient in the therapy group and two (8%) patients in the control group. Reoperation was necessary in four (16%) patients in the therapy group and 6 (24%) patients in the control group. The 30-day mortality occurred in six (24%) patients in the therapy group and four (16%) patients in the control group. CONCLUSIONS: The use of fibrin-coated collagen fleece on the cut surface of the sternum in patients with osteoporosis does not impair bone and wound healing. Furthermore, it seems to result in less sternal instability. A larger prospective study is necessary to verify the results of this explorative study.

Prophylactic intra-aortic balloon counterpulsation before surgical myocardial revascularization in patients with acute myocardial infarction.

INTRODUCTION: Prophylactic intra-aortic balloon counterpulsation (pIABC) is recommended for high-risk patients undergoing coronary artery bypass grafting (CABG) surgery. Criteria for high-risk patients benefiting from pIABC are unclear. This study aimed to specifically describe the effect of pIABC on outcomes of patients with acute myocardial infarction (AMI) undergoing CABG. METHODS: In 178 of 484 AMI patients (non-ST-segment elevation myocardial infarction [NSTEMI] or ST-segment elevation myocardial infarction [STEMI] ≤5 days before surgery) without cardiogenic shock who underwent CABG between 2008 and 2013, pIABC was initiated preoperatively. After propensity score matching, the outcomes of 400 patients were analyzed (pIABC: 150; Control: 250). RESULTS: After propensity score matching, baseline and operative characteristics were balanced between the groups except for a higher rate of patients with a left ventricular ejection fraction (LVEF)≤30% in the pIABC group (26% vs. Control: 13%; p=0.032). Seven point two percent (7.2%) of the control patients received an IABP intraoperatively or postoperatively. Postoperative extracorporeal life support (ECLS) was only needed in the control group (1.2% vs. 0%; p=0.01). Postoperative plasma curves of troponin I, creatine kinase (CK) and creatine kinase isoform MB (CK-MB) levels were reduced in the pIABC group compared with the control group. In-hospital mortality was reduced in the pIABC group (3.3% vs. control: 6.4%; p=0.18). After multivariate adjustment for other preoperative risk factors, pIABC was significantly protective concerning in-hospital mortality (HR 0.56; 95%-CI 0.023-0.74; p=0.021). Mortality (pIABC vs. control) was more affected in patients with preoperative LVEF≤30% (2/36 (5.6%) vs. 6/31 (19%); heart rate (HR) 0.25; 95%-CI 0.046-1.3; p=0.13) compared with LVEF>30% (3/114 (2.6%) vs. 10/219 (4.6%); HR 0.56; 95%-CI 0.15-2.1; p=0.55). Long-term survival did not differ between the groups. CONCLUSIONS: pIABC in CABG for AMI is associated with reduced perioperative cardiac injury and in-hospital mortality. Long-term survival is not affected.

Active Chest Tube Clearance After Cardiac Surgery Is Associated With Reduced Reexploration Rates.

BACKGROUND: Ineffective evacuation of intrathoracic fluid after cardiac surgery (retained blood syndrome [RBS]) might increase postoperative complications, morbidity, and mortality. Active tube clearance (ATC) technology using an intraluminal clearing apparatus aims at increasing chest tube drainage efficiency. This study evaluated whether ATC reduces RBS in an all-comers collective undergoing scheduled cardiac surgery with cardiopulmonary bypass and full or partial median sternotomy. METHODS: In this nonrandomized prospective trial, 581 consecutive patients undergoing scheduled cardiac surgery with median sternotomy between January 2016 and December 2016 were assigned to receive conventional chest tubes (control group) or a combination of conventional tubes and as many as two ATC devices (ATC group), depending on their operation date. Postoperative occurrence of RBS (one or more of the following: reexploration for bleeding or tamponade, pericardial drainage procedure, pleural drainage procedure) and other endpoints were compared. Propensity score matching was applied. RESULTS: In 222 ATC patients and 222 matched control patients, RBS occurrence did not differ between the groups (ATC 16%, control 22%; p = 0.15). However, reexploration rate for bleeding or tamponade was significantly reduced in the ATC group compared with the control group (4.1% versus 9.1%, respectively; p = 0.015). The mortality of RBS patients (21%) was higher compared with patients without RBS (3.9%, p < 0.001). Among the RBS components, only reexploration (odds ratio 16, 95% confidence interval: 5.8 to 43, p < 0.001) was relevant for inhospital mortality (ATC 6.8%, control 7.7%; p = 0.71). CONCLUSIONS: Active tube clearance is associated with reduced reexploration rates in an all-comers collective undergoing cardiac surgery. Reexploration is the only RBS component relevant for mortality. The ATC effect does not translate into improved overall survival.

Total arterial revascularization in patients with acute myocardial infarction - feasibility and outcomes.

BACKGROUND: In acute situations such as acute myocardial infarction (AMI) with indication for coronary artery bypass grafting (CABG), total arterial revascularization (TAR) is often rejected in favour of saphenous vein (SV) grafting, which is assumed to allow for quicker vessel harvesting, a simpler anastomosis technique, and thus quicker revascularization and fewer bleeding complications. The aim of this study was to evaluate whether reluctance to apply TAR in AMI is still justified from a technical point of view in the current era and whether superiority of TAR results is also evident in emergency patients with AMI undergoing CABG. METHODS: In this retrospective analysis of 434 consecutive patients undergoing CABG for AMI with either TAR or with a combination of one internal mammary artery and SV grafts between 2008 and 2014, procedural data, short-term and mid-term outcome were compared. Propensity score matching of the groups was performed. RESULTS: After propensity score matching, 250 patients were included in the analysis (TAR group: n = 98; SV group n = 152). The procedural time (TAR group: 211 min vs. SV group: 200 min, p = 0.46) did not differ between the groups. Erythrocyte transfusion rates were higher in the SV group (76% vs. 57%; p < 0.001). Rates of re-exploration for bleeding did not differ. Thirty-day mortality rates were comparable (TAR group: 3.4% vs. SV group: 4.5%, p = 0.68). Kaplan-Meier analysis until 7 years postoperatively revealed a tendency for improved survival after TAR (75% vs. 62%; log-rank p = 0.12). CONCLUSION: TAR neither impairs rapid revascularization nor reduces its safety in patients with AMI. It may result in improved long-term outcome and should be preferred in the clinical setting of AMI.

International survey on the perioperative management of pulmonary endarterectomy: the perfusion perspective.

INTRODUCTION: Pulmonary endarterectomy (PEA) is the most effective treatment available for chronic thromboembolic pulmonary hypertension (CTEPH). Patient selection, surgical technique and perioperative management have improved patient outcomes, which are traditionally linked to surgical and center experience. However, optimal perfusion care has not been well defined. The goal of the international survey was to better characterize the contemporary perfusion management of PEA and highlight similarities and controversies. METHOD: The combined caseload of 15 participating centers was 5,066 cases. Topics queried included materials and types of cardiopulmonary bypass (CPB) equipment, choice of prime, fluid management, deep hypothermia strategy, temperature management, treatment of acid-base abnormalities and intraoperative hematocrit as well as anticoagulation management for heparin-induced thrombocytopenia. CONCLUSION: Our assessment could provide a base for further advancement and may help design future studies to elucidate the impact of perfusion in this challenging field.

Endovascular treatment of the ascending aorta using a combined transapical and transfemoral approach.

In high-risk patients with diseases of the ascending aorta, endovascular repair might be a therapeutic alternative to surgical repair. We developed a combined access route with transapical and transfemoral externalization of the wire and report the operative technique as well as our initial experience of six patients treated with this method. Improved wire control resulted in precise deployment of endovascular prostheses, respecting the integrity of the coronary ostia and the supra-aortic vessels. Procedural success was 100%, and follow-up until 32 months postoperatively showed no need for reintervention or mortality. However, long-term results of the presented technique are still unknown.

Safety of Simultaneous Coronary Artery Bypass Grafting and Carotid Endarterectomy Versus Isolated Coronary Artery Bypass Grafting: A Randomized Clinical Trial.

BACKGROUND AND PURPOSE: The optimal operative strategy in patients with severe carotid artery disease undergoing coronary artery bypass grafting (CABG) is unknown. We sought to investigate the safety and efficacy of synchronous combined carotid endarterectomy and CABG as compared with isolated CABG. METHODS: Patients with asymptomatic high-grade carotid artery stenosis ≥80% according to ECST (European Carotid Surgery Trial) ultrasound criteria (corresponding to ≥70% NASCET [North American Symptomatic Carotid Endarterectomy Trial]) who required CABG surgery were randomly assigned to synchronous carotid endarterectomy+CABG or isolated CABG. To avoid unbalanced prognostic factor distributions, randomization was stratified by center, age, sex, and modified Rankin Scale. The primary composite end point was the rate of stroke or death at 30 days. RESULTS: From 2010 to 2014, a total of 129 patients were enrolled at 17 centers in Germany and the Czech Republic. Because of withdrawal of funding after insufficient recruitment, enrolment was terminated early. At 30 days, the rate of any stroke or death in the intention-to-treat population was 12/65 (18.5%) in patients receiving synchronous carotid endarterectomy+CABG as compared with 6/62 (9.7%) in patients receiving isolated CABG (absolute risk reduction, 8.8%; 95% confidence interval, -3.2% to 20.8%; PWALD=0.12). Also for all secondary end points at 30 days and 1 year, there was no evidence for a significant treatment-group effect although patients undergoing isolated CABG tended to have better outcomes. CONCLUSIONS: Although our results cannot rule out a treatment-group effect because of lack of power, a superiority of the synchronous combined carotid endarterectomy+CABG approach seems unlikely. Five-year follow-up of patients is still ongoing. CLINICAL TRIAL REGISTRATION: URL: https://www.controlled-trials.com. Unique identifier: ISRCTN13486906.

Is delayed surgical revascularization in acute myocardial infarction useful or dangerous? New insights into an old problem.

OBJECTIVES: Haemodynamically stable patients admitted for coronary artery bypass grafting in acute myocardial infarction often undergo delayed surgery in order to avoid the risks of emergency surgery. However, initially stable patients undergoing delayed surgery may develop low cardiac output syndrome (LCOS) during the waiting period, which might be a major drawback of this strategy. We aim to define risk factors and clinical consequences of LCOS during the waiting period. METHODS: A total of 530 consecutive patients with acute myocardial infarction (33% non-ST-segment elevation myocardial infarction and 67% ST-segment-elevation myocardial infarction) underwent isolated coronary artery bypass grafting between 2008 and 2013. Outcomes after either immediate (<48 h after onset of symptoms) or delayed (>48 h after onset of symptoms) therapy were compared. Predictors of preoperative development of LCOS were identified using multivariate regression analysis. RESULTS: Of the 327 patients undergoing delayed therapy, 39 (12%) developed preoperative LCOS, resulting in increased mortality compared with patients who remained stable (21 vs 7.6%, P < 0.001). Immediate therapy resulted in similar mortality compared with delayed therapy (6.4 vs 7.6%; P = 0.68) and better 7-year survival (70 vs 55%; P < 0.001). Predictors of developing LCOS were reduced left ventricular function (odds ratio 4.4), renal impairment (odds ratio 3.0), acute pulmonary infection (odds ratio 3.4) and the extent of troponin elevation at admission (odds ratio 1.01 per increase by 1 µg/l). CONCLUSIONS: In patients with acute myocardial infarction undergoing delayed coronary artery bypass grafting, preoperative LCOS is a relevant and dangerous condition that can be avoided by operating immediately or by carefully selecting patients to be delayed according to the risk parameters identified preoperatively.

Reactive Conjugated Polymers: Synthesis, Modification, and Electrochemical Properties of Polypentafluorophenylacetylene (Co)Polymers.

(Co)Polymers containing pentafluorophenylacetylene (F5 PA) have been prepared for the first time mediated by [Rh(nbd)Cl]2 /NEt3 to give materials with properties typical of poly(phenylacetylene)s prepared with this catalyst/co-catalyst combination. It is demonstrated that the F5 PA repeat units in these new (co)polymers serve as convenient reactive species for post-polymerization modification with thiols via para-fluoro aromatic nucleophilic substitution reactions to give an entirely new family of novel thioether-functional polyene materials accompanied by absorption maxima shifts of up to 130 nm. Finally, the electrochemical properties of these new fluorinated polyene materials are briefly examined and the distinct difference in behavior of the F5 PA homopolymer versus polyphenylacetylene, copolymers, and functional derivatives is highlighted.

Impact of prophylactic administration of Levosimendan on short-term and long-term outcome in high-risk patients with severely reduced left-ventricular ejection fraction undergoing cardiac surgery - a retrospective analysis.

BACKGROUND: Patients with severely reduced left-ventricular ejection fraction carry a high risk of morbidity and mortality after cardiac surgery. Levosimendan can be used prophylactically in these patients having shown positive effects on short-term outcome. However, effects on long-term outcome and patient subgroups benefiting the most are unknown. We aim to address these topics with real-life data from our clinical practice. METHODS: Two hundred eigthy eight patients with preoperative LVEF ≤ 35% underwent cardiac surgery with cardiopulmonary bypass between 2009 and 2013. Thereof, 246 were included in the matched analysis. Eigthy two patients received 12.5mg Levosimendan starting at induction of anesthesia. Outcomes of patients undergoing coronary artery bypass grafting surgery (n = 103), isolated valve surgery/ascending aortic surgery (n = 45) and those undergoing combination procedures (n = 98) were analyzed separately. Additionally, multivariate regression analysis was conducted in order to identify predictors of short-term outcome parameters for different subgroups of patients. RESULTS: Thirty days mortality rates of 16% in the Levosimendan group and 21% in the control group (OR 0.7; 95%-CI 0.36-1.5; p = 0.37) were observed. Levosimendan showed a positive effect on postoperative renal function. A higher rate of new-onset atrial fibrillation (OR 4.0; 95%-CI 2.2-7-2; p < 0.0001) was observed in the Levosimendan group. Follow-up until three years postoperatively showed no differences in long-term survival between the groups. CONCLUSION: Prophylactic administration of Levosimendan did not affect overall short- and long-term outcomes. The value of prophylactic use of Levosimendan remains questionable and more data is needed to confirm subgroups that might benefit most.

Are aortic valve reoperations after primary replacement with stentless heart valve prostheses more demanding than after stented biological prostheses?

OBJECTIVE: Reoperations after aortic valve replacement (AVR) with stentless valve prostheses are believed to be surgically more difficult than after stented prostheses. METHODS: Between January 1996 and December 2006, 1,340 of 3,785 patients with AVR in a single institution received a stentless valve prosthesis in aortic position (Medtronic Freestyle, Medtronic GmbH, Meerbusch, Germany). Reoperations after stentless AVR occurred in 27 patients (2.0%). Twenty-four of these patients were compared with another 24 patients having redo surgery after a primary stented bioprosthesis after carrying out propensity score matching. RESULTS: After matching, stentless valve redo patients had a similar preoperative risk profile regarding EuroSCORE (stentless 10 ± 3 points/stented 11 ± 3 points; p = 0.37), preoperative active endocarditis (stentless 37.5%/stented 16.7%; p = 0.081), and amount of concomitant procedures (stentless 37.5%/stented 16.7%; p = 0.222). Thirty-day mortality after reoperation was 20.8% (5 patients) in the stentless and 4.2% (1 patient) in the stented group (p = 0.081), and reintubation rate was 16.7% in the stentless and 0% in the stented group (p = 0.037). Aortic clamping time (stentless 90 ± 25 min/stented 86 ± 34 min; p = 0.208) and extracorporeal circulation time (stentless 151 ± 59 min/stented 132 ± 52 min; p = 0.55) were similar in both groups. CONCLUSION: Our data do not show that the technical difficulty of reoperations after stentless AVR is higher than that of reoperations after stented AVR. The clinically visible, but not statistically significant, higher early mortality rate of our stentless group is mainly due to more active valve prosthesis endocarditis cases and a higher amount of concomitant procedures.

Temporary epicardial pacemaker wires: significance of position and electrode type.

OBJECTIVE: To determine the pacing and sensing properties of different temporary epicardial pacemaker electrodes after cardiac surgery depending on position at the heart and time after surgery. METHODS: From September 2009 to October 2010, 60 patients undergoing cardiac surgery were prospectively randomized into two groups: group O: Osypka-electrodes (n = 30), group M: Medtronic-electrodes (n = 30). In position 1, the bipolar electrodes were inserted onto the anterior wall of the right ventricle and at the right atrial auricle, in position 2, onto the diaphragmal wall of the right ventricle and at the aortic aspect of the superior vena cava medial close to the atrium. Sensing values and pacing thresholds were measured for all electrodes during surgery, on day 1 and every second day up to day 10 after surgery. RESULTS: In both groups, pacing thresholds (both positions) were higher during surgery (ventricle 3.1 ± 0.6 V, atrium 3.1 ± 0.3 V) than at day 1 (ventricle 2.4 ± 0.7 V, atrium 2.4 ± 0.3 V) and increased during the perioperative course until day 10 (ventricle 4.7 ± 1.0 V, atrium 4.9 ± 1.1 V, p = 0.04, p = 0.02). P and R wave amplitudes did not change over time (atrium 5.1 ± 0.1 mV initially, 4.2 ± 0.1 mV at removal (p = ns); ventricle 10.4 ± 0.2 mV vs. 10.1 ± 0.25 mV). Group M had better median pacing thresholds compared with group O (atrium: 2.9 ± 0.6 V vs. 3.9 ± 0.7 V, p = 0.04 and ventricle: 2.6 ± 0.6 V vs. 3.9 ± 0.6 V, p = 0.045). Atrial position 1 was superior to position 2 concerning pacing thresholds of Medtronic electrodes (2.1 ± 0.3 mV vs. 3.4 ± 0.4 mV, p = 0.02). Osypka-electrodes were easier to handle due to their more pliable texture. CONCLUSIONS: 1. Up to postoperative day 10, adequate pacing and sensing performance was achieved by both electrode types in each position. 2. Medtronic electrodes had better pacing thresholds in atrium and ventricle after day 5. 3. Positioning of pacemaker electrodes does not alter functionality. 4. Handling of Osypka electrodes was easier than that of Medtronic electrodes.

Prophylactic intra-aortic balloon counterpulsation in cardiac surgery: it is time for clear evidence.

In the previous issue of Critical Care, Yu and colleagues report increased morbidity and mortality in patients after myocardial infarction undergoing prophylactic intra-aortic balloon pump support before coronary artery bypass graft surgery. The impact of prophylactic intra-aortic balloon pump implantation before coronary artery bypass graft therapy still is controversially debated. However, Yu and colleagues emphasize further discussion and substantiate the need for a prospective randomized controlled trial on this subject.

Posttraumatic arteriovenous fistula of the distal posterior tibial artery as cause of delayed wound healing in an unrecognized arterial injury.

Background Cases of posttraumatic arteriovenous (AV) fistula of the distal lower limb are rarely reported. Time from trauma to diagnosis varies from hours to years. Case Description This case report of a 51-year-old male patient shows very impressively the extensive consequences of an unrecognized traumatic AV fistula. The fistula developed here after a car accident led to a massive healing delay in a pilon fracture of the tibia and a wound, resulting in almost 1 year immobilization, 20 operations, and extensive pain drug therapy. After surgical revision of the fistula, bone and wound healing improved quickly. Conclusions The possibility of an AV fistula should be considered in case of persistent swelling after high-energy trauma of an extremity. The therapy of choice is surgery and the long-term result of successful fistula ligature is excellent.

Short- and long-term outcomes in octogenarians after coronary artery bypass surgery.

OBJECTIVES: Coronary artery surgery in octogenarians is carried out with an increasing frequency. We tried to determine short- and long-term outcomes and quality of life after coronary artery surgery in this patient group. METHODS: From 3312 patients undergoing isolated coronary artery bypass graft (CABG) surgery in two centres in the years 2004-06, 240 (7.2%) were older than 80 years (mean age 82.3 years, 57.1% male). The octogenarians were analysed regarding perioperative major adverse cardiac and cerebrovascular events (MACCE), late mortality and health-related quality of life (SF-12 questionnaire) and compared with 376 younger patients (mean age 66.8 years, 61.4% male) using propensity score matching. The mean follow-up time of 30-day survivors was 53 months, and follow-up completeness was 97.1%. RESULTS: The octogenarians' 30-day mortality rate was 6.8% (vs 1.6% in the younger group). In the multivariate analysis, age was a risk factor for early death [odds ratio (OR) 4.28, 95% confidence interval (CI): 1.59-11.53] and perioperative MACCE (OR 2.78, 95% CI:1.44-5.37). One-year and 3-year survivals were 94.5 and 81.4% in the octogenarians and 98 and 91.3% in the younger group. Four years after surgery, 95.2% of the octogenarians lived alone, with a partner or with relatives, and only 4.0% required permanent nursing care. 83.9% of the octogenarians would recommend surgery to their friends and relatives for relief of symptoms. CONCLUSIONS: Octogenarians can undergo CABG surgery with an acceptable risk of early death. Though late mortality is high, late quality of life is comparable with that of younger patients.