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Our objective was to determine the relationship between heifer carcass maturity and beef palatability of the longissimus lumborum (LM) and biceps femoris (BF). Left sides of A (n = 30), B (n = 30), and C (n = 30) maturity heifer carcasses under 30 mo of age by dentition were used. Carcasses were selected to ensure similar marbling scores across maturity groups (Small to Modest). Beef strip loins (LM) and outside rounds (BF) were obtained from these carcasses. Steaks were used to measure color stability, lipid oxidation (thiobarbituric acid reactive substances; TBARS), Warner-Bratzler shear force (WBSF), soluble and insoluble collagen, and consumer sensory perceptions. Heifer carcass maturity did not affect pH, fluid loss, WBSF, or collagen content of LM or BF steaks (P > 0.29). In LM and BF steaks, a maturity × day of retail display interaction occurred for TBARS, in which B maturity steaks had lower levels of lipid oxidation compared with A and C maturity steaks from the fourth day to the end of the retail display (P < 0.01). Nevertheless, LM steaks from B maturity carcasses tended to have lower overall acceptability (P = 0.08) and juiciness (P = 0.09) than steaks from C maturity carcasses, but steaks from B and C maturity carcasses did not differ from LM steaks obtained from A maturity carcasses. No differences in tenderness or flavor were observed due to maturity (P > 0.24). Similarly, maturity had no effect on sensory characteristics of BF steaks (P > 0.30). In conclusion, our results indicate that advanced physiological maturity does not decrease palatability of strip loin or outside round steaks from carcasses of heifers under 30 mo of age.

WC cemented carbides with a greener alternative binder to Co, AISI 304 stainless steel (SS), were processed through high energy ball milling (HEBM). The milling parameters, such as rotation speed, ball-to-powder ratio and milling time were investigated. Selected milling conditions were applied to obtain a nanosized powder of WC-12 wt% SS with a highly uniform distribution of the ductile phase. For comparison, a conventionally wet milled powder was also prepared. Both powders were thermally characterized by dilatometry, up to 1450 °C, using vacuum atmosphere, and structural and microstructural analysis were performed in the sintered samples. The nanometric size of the HEBM powder particles markedly affected its densification and thermal reactivity; when compared with the micrometric powder obtained from conventional milling, early starting densification, with a greater contribution of solid state sintering, and increased reactivity, with formation of a larger amount of (M,W)6C phase, was noticed during sintering of HEBM powder compacts.

In this work, we focus on the problem of selecting low-level heuristics in a hyperheuristic approach with offline learning, for the solution of instances of different problem domains. The objective is to improve the performance of the offline hyperheuristic approach, identifying equivalence classes in a set of instances of different problems and selecting the best performing heuristics in each of them. A methodology is proposed as the first step of a set of instances of all problems, and the generic characteristics of each instance and the performance of the heuristics in each one of them are considered to define the vectors of characteristics and make a grouping of classes. Metalearning with statistical tests is used to select the heuristics for each class. Finally, we used the Naive Bayes to test the set instances with k-fold cross-validation, and we compared all results statistically with the best-known values. In this research, the methodology was tested by applying it to the problems of capacitated vehicle routing (CVRP) and graph coloring (GCP). The experimental results show that the proposed methodology can improve the performance of the offline hyperheuristic approach, correctly identifying the classes of instances and applying the appropriate heuristics in each case. This is based on the statistical comparison of the results obtained with those of the state of the art of each instance.

ObjectivesThe study objectives were to compare the deep (D) vs. superficial (S) portions of the beef top round (NAMI #169A PSO1), semimembranosus (SM) muscle, for tenderness, lipid oxidation, and color.Materials and MethodsTo simulate the retail setting, USDA Choice top rounds (n = 12) were purchased from a commercial food distributer and delivered to the University of Idaho Meat Science Laboratory under refrigeration. Top rounds were aged for 21 to 24 d from their pack date prior to removing the SM for subsequent analysis. Four steaks were cut from each SM proximally to distally. To account for steak location, steaks were systematically assigned to one of the following analyses; Warner-Bratzler Shear Force (WBSF) measurement, lipid oxidation using the Thiobarbituric Acid Reactive Substances (TBARS) method, subjective and objective color analysis on the whole steak to calculate color uniformity (two-toning), and subjective and objective color of a steak separated into D and S portions. The separating cut was made approximately two inches from the superficial edge of the steak. After cutting, WBSF steaks were cooked on clamshell grills to an internal temperature of 71°C. Steaks were then chilled overnight before 6 cores were sheared perpendicular to the muscle fiber direction on a WBSF machine. Steaks were sampled and evaluated for TBARS on Days 0 and 4 of retail display, while color was evaluated subjectively and objectively on Days 0, 1, 2, 3, and 4 of retail display. Steaks used for TBARS and color analysis were placed on white Styrofoam trays, overwrapped with an oxygen permeable PVC film, and displayed in a glass-fronted retail display case at 3°C for 4 d to simulate retail display. Data were analyzed using the mixed models procedure of the Statistical Analysis System (SAS Institute, Inc., Cary, NC) and significance was determined at P < 0.05.ResultsMean Warner-Bratzler shear force values were lower (P = 0.0012) in the S (4.2 kg) than the D (5.2 kg) portion of the SM. On Day 0, D and S portions had similar TBARS values (0.172 vs. 0.118 mg MDA/kg Meat); yet, by Day 4, the D portion had substantially greater TBARS values than the S portion (0.497 vs. 0.194 mg MDA/kg Meat; treatment × day of retail display interaction, P < 0.0001). The D portion was lighter (higher L*; P < 0.0001) colored than the S portion. Furthermore, the D portion became less red compared to the S portion during simulated retail display (treatment × day of retail display interaction; P < 0.0001). The whole steak had greater levels of two-toning initially, as well as throughout the 4 d of retail display, compared to the D and S portions (treatment × day of retail display interaction; P < 0.0001). Therefore, cutting top round steaks into a D and S portion would result in the steaks being more uniform in color. Additionally, the S portion has longer shelf-life as well as improved tenderness compared to the D portion.ConclusionIn conclusion, the S portion may be able to generate a premium compared to the whole steak at the retail level because of its superiority in color to the D portion and more uniform color compared to the whole steak.

Proper tuning of hyper-parameters is essential to the successful application of SVM-classifiers. Several methods have been used for this problem: grid search, random search, estimation of distribution Algorithms (EDAs), bio-inspired metaheuristics, among others. The objective of this paper is to determine the optimal method among those that recently reported good results: Bat algorithm, Firefly algorithm, Fruit-fly optimization algorithm, particle Swarm optimization, Univariate Marginal Distribution Algorithm (UMDA), and Boltzmann-UMDA. The criteria for optimality include measures of effectiveness, generalization, efficiency, and complexity. Experimental results on 15 medical diagnosis problems reveal that EDAs are the optimal strategy under such criteria. Finally, a novel performance index to guide the optimization process, that improves the generalization of the solutions while maintaining their effectiveness, is presented.

The exponential rise of power dissipation in electric devices has so far vastly surpassed the performance of power converter systems. New thermal management solutions are therefore in high demand to maintain devices at their optimal temperature and efficiency. Here, we present an innovative magnetically actuated thermal switch (MATS) based on nanofluids capable of controlling both the magnitude and direction of the heat flux. When in the OFF state (zero applied magnetic field), the nanofluid captures the heat being generated at the heat source. When an external magnetic field is applied (ON state), the nanofluid is transported from the heat source to the heat sink where it releases the carried heat. This work (i) provides a detailed description of the MATS operating principles, (ii) studies the effect of thickness and operation frequency in its cooling power, (iii) presents numerical simulations to forecast MATS behavior and (iv) demonstrates the MATS applicability in the thermal management of a 10 W Light Emitting Diode. The versatility, simple design, unique operating mode and high performance of the MATS suggests that the proposed approach is a promising technology to be used in a vast number of electronic devices, thermal storage systems and thermal management applications.

Alternative binders to cobalt, based on stainless steel (SS, AISI304) and copper were investigated for tungsten carbide (WC) based cemented carbides. The binder content was fixed at 12 wt%, and the Cu:SS ratio varied in proportions of 0:1, 1:5, 1:2, 1:1, 1:0. High energy ball milling was applied to ensure high homogenization, nanometric particle size and mechanical alloying of binder elements in the powders' mixtures. To assess an adequate sintering route, wettability testing and constant heating rate dilatometry in vacuum were performed. The composites were analyzed in terms of their structural, microstructural and mechanical characteristics. The poor wettability of melted Cu on WC surfaces was increased by alloying it with SS and highly dense compacts could be successfully attained at reduced vacuum sintering temperatures with binders having a Cu:SS ratio equal to or lower than 1:2. The microstructures show secondary phases and significant grain coarsening during sintering, whereas the average grain size was kept in the nanometric range. The composites that attained almost full densification present high hardness, comparable to that of nanometric WC-12Co cemented carbides processed by similar routes, but lower toughness values.

Artificial Neural Networks (ANNs) have been successfully used in Pattern Recognition tasks. Evolutionary Spiking Neural Networks (ESNNs) constitute an approach to design thirdgeneration ANNs (also known as Spiking Neural Networks, SNNs) involving Evolutionary Algorithms (EAs) to govern some intrinsic aspects of the networks, such as topology, connections and/or parameters. Concerning the practicality of the networks, a rather simple standard is commonly used; restricted feed-forward fully-connected network topologies deprived from more complex connections are usually considered. Notwithstanding, a wider prospect of configurations in contrast to standard network topologies is available for research. In this paper, ESNNs are evolved to solve pattern classification tasks, using an EA-based algorithm known as Grammatical Evolution (GE). Experiments demonstrate competitive results and a distinctive variety of network designs when compared to a more traditional approach to design ESNNs.

This paper presents a grammatical evolution (GE)-based methodology to automatically design third generation artificial neural networks (ANNs), also known as spiking neural networks (SNNs), for solving supervised classification problems. The proposal performs the SNN design by exploring the search space of three-layered feedforward topologies with configured synaptic connections (weights and delays) so that no explicit training is carried out. Besides, the designed SNNs have partial connections between input and hidden layers which may contribute to avoid redundancies and reduce the dimensionality of input feature vectors. The proposal was tested on several well-known benchmark datasets from the UCI repository and statistically compared against a similar design methodology for second generation ANNs and an adapted version of that methodology for SNNs; also, the results of the two methodologies and the proposed one were improved by changing the fitness function in the design process. The proposed methodology shows competitive and consistent results, and the statistical tests support the conclusion that the designs produced by the proposal perform better than those produced by other methodologies.

Evolutionary Artificial Neural Networks (EANNs) are a special case of Artificial Neural Networks (ANNs) for which Evolutionary Algorithms (EAs) are used to modify or create them. EANNs adapt their defining components ad hoc for solving a particular problem with little or no intervention of human expert. Grammatical Evolution (GE) is an EA that has been used to indirectly develop ANNs, among other design problems. This is achieved by means of three elements: a Context-Free Grammar (CFG) which includes the ANNs defining components, a search engine that drives the search process and a mapping process. The last component is a heuristic for transforming each GE’s individual from its genotypic form into its phenotypic form (a functional ANN). Several heuristics have been proposed as mapping processes in the literature; each of them may transform a specific individual’s genotypic form into a very different phenotypic form. In this paper, partially-connected ANNs are automatically developed by means of GE. A CFG is proposed to define the topologies, a Genetic Algorithm (GA) is the search engine and three mapping processes are tested for this task; six well-known pattern recognition benchmarks are used to statistically compare them. The aim of this work for using and comparing different mapping process is to analyze them for setting the basis of a generic framework to automatically create ANNs.

Texture classification is a problem widely studied in computer vision, there exist two fundamental issues: how to describe texture images and how to define a similarity measure. The texture descriptors are mainly used to extract and represent the features of texture images and their performance is usually measured using a classification algorithm. In this paper, some of the most referenced texture descriptors, such as Gabor filter banks, Wavelets, and Local Binary Patterns, are compared using non-parametric statistical tests to know if there is a difference in performance. The descriptors are applied to five well-known texture image datasets, in order to be classified. Three classification algorithms, with a cross-validation scheme, are used to classify the described texture datasets. Finally, a Friedman test with multiple comparisons is used to compare the whole performance of the texture descriptors on a statistical basis. The statistical results suggest that for these tests there is a difference in performance, so it was possible to determine statistically, for the considered experimental settings, the best texture descriptor.

Grammatical Evolution (GE) is a grammar-based form of Genetic Programming. In GE, a Mapping Process (MP) and a Backus–Naur Form grammar (defined in the problem context) are used to transform each individual’s genotype into its phenotype form (functional representation). There are several MPs proposed in the state-of-the-art, each of them defines how the individual’s genes are used to build its phenotype form. This paper compares two MPs: the Depth-First standard map and the Position Independent Grammatical Evolution (πGE). The comparison was performed using as use case the problem of the selection and generation of features for pattern recognition problems. A Wilcoxon Rank-Sum test was used to compare and validate the results of the different approaches.

Sixty years ago, at the Mayo Clinic in Rochester, Minnesota, an ambitious group of pioneers, led by Dr John W. Kirklin and supported by a multidisciplinary team of physicians and technicians embarked on a planned series of surgical cases using a heart-lung machine to allow direct visualization of the inside of the opened human heart to repair otherwise fatal congenital intracardiac defects. Their success sparked the beginning of a new era of open-heart surgery. In this historical article, we discuss the contributions of a few key figures of this revolution and also share the story of the first successful cardiac surgery operation using cardiopulmonary bypass performed at Mayo Clinic.

The gluon momentum density xg ( x , Q 2 ) of the proton was extracted at Q 2 = 20 GeV 2 for small values of x between 4 × 10 −4 and 10 −2 from the scaling violations of the proton structure function F 2 measured recently by ZEUS in deep inelastic neutral current ep scattering at HERA. The extraction was performed in two ways. Firstly, using a global NLO fit to the ZEUS data on F 2 at low x constrained by measurementsfrom NMC at larger x ; and secondly using published approximate methods for the solution of the GLAP QCD evolution equations. Consistent results are obtained. A substantial increase of the gluon density is found at small x in comparison with the NMC result obtained at larger values of x .

A bioinspired locomotion system for a quadruped robot is presented. Locomotion is achieved by a spiking neural network (SNN) that acts as a Central Pattern Generator (CPG) producing different locomotion patterns represented by their raster plots. To generate these patterns, the SNN is configured with specific parameters (synaptic weights and topologies), which were estimated by a metaheuristic method based on Christiansen Grammar Evolution (CGE). The system has been implemented and validated on two robot platforms; firstly, we tested our system on a quadruped robot and, secondly, on a hexapod one. In this last one, we simulated the case where two legs of the hexapod were amputated and its locomotion mechanism has been changed. For the quadruped robot, the control is performed by the spiking neural network implemented on an Arduino board with 35% of resource usage. In the hexapod robot, we used Spartan 6 FPGA board with only 3% of resource usage. Numerical results show the effectiveness of the proposed system in both cases.

Objective Patients with complex cyanotic congenital heart disease and a bidirectional cavopulmonary connection who are not candidates for or had failed Fontan operation may experience progressive cyanosis. An axillary arteriovenous anastomosis may be constructed to augment pulmonary blood flow. This report reviews our results with this approach in this complex group of patients. Methods The records of patients with previous cavopulmonary connections who underwent a surgical anastomosis between the axillary artery and the vein for palliation of severe progressive cyanosis were reviewed. Results Eleven patients were identified. The median age at the time of the axillary arteriovenous anastomosis was 19.2 years (7.97–41.75 years). Seven patients were not candidates for the Fontan operation, and 4 patients had failed Fontan surgery. Three of the anastomoses were constructed with a side-to-side technique, and 8 anastomoses were constructed with a short interposition graft. Median fistula size was 5 mm (3–6 mm). There was no operative mortality and 1 late death. Median survival was 2.85 years (0.01–7.22 years). All fistulae were patent at follow-up. Median preoperative arterial oxygen saturation was 84% (80%–86%) and 82% (76%–88%) at follow-up (P = .38). Median preoperative hemoglobin was 18.5 g/dL (11.7–22.6 g/dL) and 19.2 g/dL (14.6–22.6 g/dL) at follow-up (P = .97). Median preoperative systemic ventricular ejection fraction was 51% (27%–60%) and 46.5% (28%–60%) at follow-up (P = 1). Significant functional improvement was seen in only 1 patient. Conclusions In patients with complex cyanotic congenital heart disease who are not candidates for or had failed Fontan operation, palliation with an axillary arteriovenous fistula did not improve cyanosis or polycythemia. Functional outcome and ventricular ejection fraction did not improve or deteriorate.

This paper deals with the application of the fringe-projection method for the measurement of large object surfaces. In this case, the generated fringe pattern is equivalent to that obtained by using divergent beams, i.e. the relation between phase and height is not linear. In this work, both the pitch variation in x-direction of the projected grating and the perspective problem of CMOS camera are taken into account for the formulation of a novel algorithm that iteratively retrieves the correct surface point positions. The methodology is applied to a large car component and the obtained results are compared with those obtained with a commercial scanner (Z-Scanner 700).

Background Excellent surgical results have been reported after repair of complete atrioventricular septal defects (CAVSD); however, 5% to 10% require reoperation. We examine causes leading to reoperation and evaluate long-term outcome. Methods Between 1972 and 2007, 50 patients (26 male) underwent reoperation at our institution after initial repair of CAVSD (median interval, 15 months; range, 3 days to 29 years). Median age at first reoperation was 4.5 years (range, 53 days to 38 years). Indications for first reoperation included left atrioventricular valve (LAVV) regurgitation in 41 patients, subaortic stenosis in 5, and LAVV stenosis, residual atrial septal defect (ASD), pulmonary artery (PA) stenosis, and aortic coarctation in 1 each. Results The first reoperation included LAVV repair in 21 patients and replacement in 21, modified Konno procedure in 3, septal myectomy in 2, and PA reconstruction, coarctation repair, and ASD re-repair in 1 each. After LAVV repair (n = 21) 5 patients required a second reoperation, and after LAVV replacement (n = 21) 6 patients required a second reoperation. Overall freedom from further reoperation after the first reoperation was 63%, 48%, and 42% at 5, 10, and 15 years, respectively. There were 2 early deaths (4%) after first reoperation, and none after subsequent reoperations. During late follow-up (median 10.7 years, maximum 30 years), actuarial overall survival was 91%, 91%, and 86% at 5, 10, and 15 years, respectively. Conclusions The most common indication for reoperation after CAVSD repair is LAVV regurgitation. LAVV re-repair offers good durability, and LAVV replacement does not preclude additional reoperations. Long-term survival is very good despite need for multiple reoperations in some.

Background and Purpose— Embolic events have long been thought to occur in patients with cardiac tumors secondary to embolization of tumor fragments; however, there are no large studies examining the epidemiology and occurrence of embolism in this group of patients. Methods— From 1957 to 2006, 323 consecutive patients with primary cardiac tumors were treated surgically at our institution. Of these, patients who experienced an embolic event included 80 (cerebrovascular accident 31 [9.7%], transient ischemic attack 30 [9.3%], and other 19 [6%]). Those with no history of an embolic event (n=243 [75%]) were defined as control subjects. Results— Age was similar between the case and control groups (mean 54.5 versus 53.9 years, P =0.8). A multivariate logistic regression model including tumor location, tumor burden, tumor histology, and cerebrovascular risk factors, indicated that left atrial tumors (OR, 1.95; P =0.04), aortic valve tumors (OR, 4.17; P =0.002), and smaller tumor burden (OR, 2.20; P =0.01) were the most significant factors in the occurrence of embolism ( P P =0.006) and decreased functional status (New York Heart Association III/IV; OR, 0.31; P P =0.78). Conclusion— Aortic valve and left atrial tumors have the greatest anatomic risk for embolism. Furthermore, patients with smaller tumors, minimal symptomatology, and no evidence of mitral regurgitation have a high risk of embolism. Cardiac tumors can be resected with low early mortality, and late survival after operation in the context of an embolic event is similar to patients with cardiac tumors who undergo resection for other indications.

ObjectiveExtra-anatomic bypass of complex thoracic aortic disease through a median sternotomy has been reported as a safe alternative to thoracotomy. Our objective was to examine intermediate-term outcomes.MethodsWe retrospectively reviewed 50 consecutive patients with congenital aortic coarctation or recurrent coarctation who underwent ascending–descending posterior pericardial aortic bypass between January 1985 and November 2005. Demographic data, in-hospital and postoperative morbidity and mortality, and resolution of hypertension were determined by examination of the medical record.ResultsThe mean age at operation was 42 years; 27 (54%) were men. There were no perioperative deaths. Upper-extremity blood pressure after coarctation repair with ascending–descending aortic bypass was significantly improved. Mean systolic blood pressure decreased from 158 ± 25 mm Hg preoperatively to 123 ± 14 mm Hg postoperatively (P < .001). There were no graft-related deaths or complications in follow-up extending up to 20 years.ConclusionsThe ascending–descending aortic bypass through a posterior pericardial approach is a safe operation and is effective in relieving obstruction and improving hypertension.

Objective Repair of Ebstein anomaly and impaired right ventricular function pose challenges for the cardiac surgeon. The bidirectional cavopulmonary shunt may improve early outcomes. We reviewed our experience with the 1.5-ventricle repair in this patient population. Methods Between July 1999 and March 2006, 169 patients underwent operations to repair Ebstein anomaly. Fourteen patients had a bidirectional cavopulmonary shunt constructed. The median age at operation was 6 years (17 months-57.8 years). All of the patients had severe Ebstein anomaly with dilated right-sided chambers and/or right ventricular dysfunction. The mean left ventricular ejection fraction was 54.5% (range 35%–72%). Three patients were initially referred for heart transplantation, and the bidirectional cavopulmonary shunt allowed a conventional repair. Results Procedures included bidirectional cavopulmonary shunting (14), tricuspid valve replacement (11), tricuspid valve repair (2), and right ventricular resection (3). Shunting was planned preoperatively in 9 patients; the indication in 5 other patients was hemodynamic instability after separation from cardiopulmonary bypass. One patient died of multiple organ failure. Median follow-up in 10 patients was 18 months (3 months-6.5 years). The preoperative left ventricular ejection fraction of less than 50% improved in 3 patients to greater than 50% postoperatively. Conclusions The 1.5-ventricle repair can be utilized in patients with severe Ebstein anomaly and impaired right ventricular function who are at high risk for surgical treatment. We believe the bidirectional cavopulmonary shunt may be considered as a planned procedure, as an intraoperative salvage maneuver, or as an alternative to cardiac transplantation in selected patients.

OBJECTIVES We sought to evaluate the early and late results of the modified Fontan operation for patients with heterotaxy syndrome, assess variables traditionally known to correlate with poor outcome, and assess current health status of survivors after the Fontan procedure. BACKGROUND The natural history of unoperated cardiac lesions in heterotaxy is known to be poor. Therefore, the Fontan operation has been proposed to improve survival. METHODS Patients with heterotaxy were identified from the Mayo Clinic Fontan database. Hospital and outpatient records were abstracted for preoperative, operative, and postoperative clinical and hemodynamic data. All patients not known to be deceased were sent health status questionnaires. RESULTS A total of 142 patients with heterotaxy syndrome had a modified Fontan operation. Asplenia was present in 76 patients (54%). Median age at operation was 9 years (range 2 to 35 years). Median follow-up was 4 years (range 0 to 23 years). There were a total of 61 deaths (43%), with 32 (23%) within 30 days of operation or before hospital discharge. The 5-, 10-, and 15-year survival was 64%, 57%, and 53%, respectively. In the modern era (1995 to 2004) early mortality was 10%. Of the 81 survivors, questionnaires were available from 41 (51%). Eighty percent reported having no or mild symptoms. However, 19 (46%) had arrhythmias, 5 (12%) had a thromboembolic event, and 1 (2%) developed protein-losing enteropathy. CONCLUSIONS Early survival has improved for heterotaxy patients after the Fontan operation; however, late morbidity and mortality remain substantial. Better strategies for long-term treatment of this high-risk group need to be identified.

The Proper Orthogonal Decomposition (POD) method and the Galerkin projection are applied to study vibrations on an aluminum square plate. Data from the plate vibrations were obtained using a Laser Vibrometer and the Fringe Projection technique. The vibrations, within the range 100 to 5,000 Hz, on the metal plate were produced with an electrodynamical shaker. Due to the symmetrical nature of the plate, the vertical displacement velocity measurements were taken only on a rectangular grid of 7×8 points. The vertical displacement velocity measured at different locations and times, was synchronized with a full-field instantaneous image of the plate obtained from the Fringe Projection technique. The plate vibration measurements were used to calculate its eigenfunctions and the eigenvalues. It was found that a large fraction of the total energy of the vibration is contained within the first two POD modes. The essential features of the vibration are thus described by only the first two eigenfunctions. A reduced order model for the dynamical behavior is then constructed using the Galerkin projection of the equation of motion for the vertical displacement of a plate.

Background Congenital heart disease (CHD) that causes right atrial dilatation is commonly associated with atrial flutter and/or fibrillation (AFl/F). To reduce late recurrence of AFl/F in patients undergoing repair of CHD, we utilized a concomitant right-sided maze procedure. Methods From 1993 to 2003, 99 patients with CHD and associated AFl/F underwent a concomitant right-sided maze procedure at the time of CHD repair. Ages ranged from 9 to 72 years (median, 43 years). Atrial flutter and/or fibrillation was paroxysmal in 81 and chronic in 18; duration ranged from less than 1 month to 39.5 years (median, 2.9 years). Primary cardiac diagnoses were Ebstein anomaly (n = 47), other congenital tricuspid regurgitation (n = 19), univentricular heart (n = 11), isolated atrial septal defect (ASD, n=8), tetralogy of Fallot (n = 8), and other (n = 6). Results Other concomitant procedures included tricuspid valve repair or replacement (n = 70), ASD closure (n = 39), and pulmonary valve procedures (n = 18). There were 6 early deaths. At hospital dismissal, 83 patients were free of AFl/F and 63 were in sinus rhythm. Follow-up in 87 of the 93 early survivors extended up to 8 years (mean, 2.7 years). There were 4 late deaths, all from noncardiac causes. Of the 83 known late survivors, 77 (93%) were free of AFl/F. Eighty-two of the 83 survivors were in New York Heart Association class I or II. Conclusions In patients with AFl/F associated with CHD, a concomitant right-sided maze procedure at the time of intracardiac repair is effective in reducing late recurrent AFl/F. Most patients enjoy an excellent quality of life.

OBJECTIVE To analyze the effect of adjuvant perfusion techniques of the distal aorta on the outcome of traumatic thoracic aortic transections. PATIENTS AND METHODS From 1973 to 2004, 72 patients (mean age, 39 years) with thoracic aortic transections arrived alive at the emergency department. Nineteen patients arrived in extremis and underwent emergency operations, 42 patients were stable and underwent diagnostic evaluation before surgery (4 patients experienced aortic rupture during evaluation), and 11 patients presented more than 24 hours after the accident. Sixteen patients died before aortic repair could be performed. Operative repair was possible in 53 patients (46 stable and 7 in extremis). Interposition graft was performed in 47 patients, and primary repair was performed in 6 patients. Morbidity, mortality, and paraplegia rate were analyzed. RESULTS Patients in extremis had a mortality rate of 84% (16 of 19), stable patients had a mortality rate of 11% (4 of 38), patients who experienced rupture during evaluation had a mortality rate of 100% (4 of 4), and patients who underwent delayed operation had a mortality rate of 0% (0 of 11). The paraplegia rate with and without adjuvant distal aortic perfusion techniques was 2% (1 of 41 patients) and 33% (4 of 12 patients), respectively ( P =.007). Mortality and paraplegia rates were 4% and 4% for partial bypass (n=24), 42% and 33% for the clamp and sew technique (n=12), 0% and 0% for Gott shunt (n=10), and 29% and 0% for full cardiopulmonary bypass (n=7), respectively. CONCLUSIONS Although thoracic aortic transections remain a highly lethal injury, hemodynamically stable patients have a low operative mortality. Spinal cord injury is decreased by the use of adjuvant perfusion techniques that maintain distal aortic perfusion during cross-clamping of the aorta.

Background Cardiac papillary fibroelastoma is a rare benign tumor that can cause thromboembolism. We have found no large surgical series describing its treatment and outcome. Methods A retrospective review of all patients treated surgically for this tumor from 1985 to 2002. Results There were 88 patients with a mean age of 62 ± 16 years. Sixty-two (71%) were male. Cardiac papillary fibroelastoma was a primary indication for surgery in 47 (group 1, 53%) and an incidental finding in 41 (group 2, 47%). The common clinical symptoms were neurologic (group 1) and cardiac (group 2). Cardiac valves were predominantly involved (77%); the aortic valve was the most affected (52%). Other common sites were the left ventricular outflow tract (18%) and anterior mitral leaflet (11%). All heart valves were involved in one patient. Seventy-three patients (83%) had shave excision and 8 (9%) excision with valve repair. Of 5 (6%) valve replacements, 2 were for concurrent degenerative valve disease. Concomitant procedures included repair or replacement of another valve (32 %), CABG (28%), and septal myectomy (19%). Surgical mortality occurred in 1 patient (2.1%) in group 1 who had concomitant lung resection for bronchiolitis obliterans. There was no tumor recurrence, and no tumor-related late morbidity or mortality at a mean follow-up of 3 years. Conclusions Cardiac papillary fibroelastoma has a propensity to affect the anatomically contiguous structures of the aortic valve, left ventricular outflow tract, and anterior mitral leaflet. Surgical treatment by simple shave excision is low risk and can achieve good results.

Background— Sinus venosus atrial septal defect (SVASD) differs from secundum atrial septal defect by its atrial septal location and its association with anomalous pulmonary venous connection (APVC). Data on long-term outcome after surgical repair are limited. Methods and Results— We reviewed outcomes of 115 patients (mean age±SD 34±23 years) with SVASD who had repair from 1972 through 1996. APVC was present in 112 patients (97%). Early mortality was 0.9%. Complete follow-up was obtained for 108 patients (95%) at 144±99 months. Symptomatic improvement was noted in 83 patients (77%), and deterioration was noted in 17 patients (16%). At follow-up, 7 (6%) of 108 patients had sinus node dysfunction, a permanent pacemaker, or both, and 15 (14%) of 108 patients had atrial fibrillation. Older age at repair was predictive of postoperative atrial fibrillation ( P =0.033). No reoperations were required during follow-up. Survival was not different from expected for an age- and sex-matched population. Clinical improvement was more common with older age at surgery ( P =0.014). Older age at repair ( P =0.008) and preoperative New York Heart Association class III or IV ( P =0.038) were independent predictors of late mortality. Conclusions— Operation for SVASD is associated with low morbidity and mortality, and postoperative subjective clinical improvement occurs irrespective of age at surgery. Postoperative atrial fibrillation appears to be related to older age at operation. SVASD repair achieves survival similar to that of a matched population and should be considered whenever repair may impact survival or symptoms.

We use the out-of-plane electronic speckle pattern interferometry (ESPI) technique to observe cracks and fracture defects on 6061 aluminum plates under thermal stress. The geometrical shape of the ESPI pattern confirmed the existence of defects. We were able to differentiate between cracks and fracture defects using a non-contact and non-destructive technique.

The purpose of this study was to quantify and determine predictors of long-term survival and functional outcome in patients with double-inlet left ventricle (DILV) after the Fontan operation. The Fontan operation has become the procedure of choice for DILV. Early survival has improved, but mortality and morbidity persist. Record review and follow-up questionnaires were used to ascertain the status of 225 patients with DILV who had Fontan operations from 1974 to 2001 at the Mayo Clinic. The median age at operation was 9 years. The median follow-up period was 12 years (range 3 months to 25 years). There were 22 deaths (9.3%)

Background The purpose of this study was to evaluate outcomes of mitral and tricuspid valve repair after mediastinal radiation therapy. Methods From 1976 to 2001, 22 patients (mean age 61 ± 14 years) underwent mitral (n = 14), tricuspid (n = 6), or both (n = 2) valve repairs 15 ± 9 years after mediastinal radiation therapy. Concomitant procedures included coronary artery bypass graft, 11 patients; valve replacement, 6 patients (4 aortic, 3 mitral, 1 tricuspid, and 1 pulmonary); and pericardiectomy, 4 patients. Results Total follow-up was 82.5 patient-years (mean 3.7 ± 3.3 years). Early mortality was 3 patients. There were 7 late deaths, 4 of which were of cardiovascular origin. Of the 19 early survivors, 2 required subsequent valve replacements, and 1 required cardiac transplantation 3.4 ± 2.8 years after valve repair. One patient died after reoperation. In 4 patients who did not undergo reoperation, echocardiographic examinations showed progressive deterioration of their repaired valve function. Overall survival, freedom from cardiac death, and freedom from valve reoperation or cardiac transplantation at 5 years for early survivors was 66%, 85%, and 88%, respectively. New York Heart Association functional class at follow-up was I or II in 8 of the 12 late survivors. Conclusions Functional status was good in two-thirds of late survivors. However, severe dysfunction of the repaired valve developed in 32% of early survivors and 16% required further surgery. Valve repair is technically feasible in selected patients after mediastinal radiation therapy; however, the limited durability of repairs after mediastinal radiation in this series suggests that valve replacement might be preferable.

Background Advances in tissue prosthetic valve design and manufacturing have stimulated renewed interest in the use of biological valves in younger patients. This approach, however, risks reoperation. We therefore reviewed our recent experience with repeat mitral valve replacement to better define its contemporary risks. Methods Using a computerized database, we identified and compared 106 patients undergoing repeat mitral valve replacement with 562 control patients undergoing primary mitral valve replacement between January 1993 and December 2000 at our institution. Results There were no significant differences between repeat and primary surgery groups with respect to age (mean 66 ± 12 vs 64 ± 13 years), gender distribution (women 65% vs 64%), preoperative functional class, ejection fraction, or active endocarditis (6.6% vs 3.4%). The indication for reoperation in the repeat group was structural dysfunction in 49 patients (46%), paravalvular leak in 21 patients (20%), nonstructural dysfunction in 11 patients (10%), and progression of other native valve disease in 8 patients (8%). Prior prostheses were mechanical in 46 patients (43%). Mean time to reoperation was 11.5 ± 7.1 years. There were 5 deaths out of 106 patients in the repeat group (4.7%) and there were 23 deaths out of 562 patients in the control group (4.1%) ( p = NS). Multivariate analysis identified prior myocardial infarction ( p = 0.014, odds ratio 2.9) and nonelective surgical status ( p = 0.004, odds ratio 2.3) as significant predictors of operative mortality. Conclusions The risk of repeat mitral valve replacement was low suggesting that there should be less reluctance to recommend patients choose a bioprosthesis over a mechanical prosthesis. Given the expected durability of current designs, bioprosthetic use may be explored in younger patients without subjecting those individuals to excessive risk.