Bacterial recovery and recycling of tellurium from tellurium-containing compounds by Pseudoalteromonas sp. EPR3.

AIMS: Tellurium-based devices, such as photovoltaic (PV) modules and thermoelectric generators, are expected to play an increasing role in renewable energy technologies. Tellurium, however, is one of the scarcest elements in the earth's crust, and current production and recycling methods are inefficient and use toxic chemicals. This study demonstrates an alternative, bacterially mediated tellurium recovery process. METHODS AND RESULTS: We show that the hydrothermal vent microbe Pseudoalteromonas sp. strain EPR3 can convert tellurium from a wide variety of compounds, industrial sources and devices into metallic tellurium and a gaseous tellurium species. These compounds include metallic tellurium (Te(0)), tellurite (TeO3(2-)), copper autoclave slime, tellurium dioxide (TeO2), tellurium-based PV material (cadmium telluride, CdTe) and tellurium-based thermoelectric material (bismuth telluride, Bi2Te3). Experimentally, this was achieved by incubating these tellurium sources with the EPR3 in both solid and liquid media. CONCLUSIONS: Despite the fact that many of these tellurium compounds are considered insoluble in aqueous solution, they can nonetheless be transformed by EPR3, suggesting the existence of a steady state soluble tellurium concentration during tellurium transformation. SIGNIFICANCE AND IMPACT OF THE STUDY: These experiments provide insights into the processes of tellurium precipitation and volatilization by bacteria, and their implications on tellurium production and recycling.

Clinical and oncological outcomes after surgical excision of pigmented villonodular synovitis at the foot and ankle.

BACKGROUND: Pigmented villonodular synovitis (PVNS) is a rare benign neoplastic disease of the synovium of joints and tendon sheaths, which may be locally aggressive. It can be broadly classified into localised disease or more diffuse forms, with the latter more prone to recurrence after surgical excision. We describe our experience in the management of foot and ankle PVNS, focusing on the diffuse type. METHODS: Patients with PVNS were identified from a histology database from 2000 to 2010 at the University Hospitals of Leicester. The primary aim was to determine oncological outcomes and evaluate clinical outcomes with the Toronto Extremity Salvage Score (TESS) and the American Academy of Foot and Ankle Surgeons (AOFAS) scores. RESULTS: 30 patients, 16 males and 14 females with a mean age of 37±15 years, who underwent surgery, were identified. There were 22 nodular PVNS and 8 diffuse PVNS. The diffuse PVNS was more likely to be in the hindfoot (75%, 6/8), of which 50% (3/6) had osteoarthritis at presentation. The localised PVNS was mostly located in the forefoot (91%, 20/22). None of the localised PVNS had a recurrence. The surgical recurrence rate in this series was similar to the pooled recurrence rate from the literature [12.5% (1/8) compared to 12.2% (6/49)]. The mean TESS and AOFAS scores were 86 and 78, respectively. CONCLUSIONS: Diffuse PVNS is more likely to occur in the hindfoot and nodular PVNS is more common in the forefoot. Aggressive synovectomy alone is an effective treatment for diffuse PVNS, with good oncological and clinical outcomes.

Van der Waals Epitaxial Growth of agr-Alumina Nanocrystals on Mica.

Lattice mismatch stresses, which severely restrict heteroepitaxial growth, are greatly minimized when thin alumina films are grown by means of van der Waals forces on inert mica substrates. A 10-nanometer-thick epitaxial film exhibits crystallographic sixfold symmetry, a lattice constant close to that of the basal plane [0001] of alpha-alumina (sapphire), and an aluminum: oxygen atomic ratio of 1:1.51 +/- 0.02 (measured by x-ray photoelectron spectroscopy), again the same as for bulk sapphire. The film is free of steps and grain boundaries over large areas and appears to be an ideal model system for studying adhesion, tribology, and other surface phenomena at atomic scales.

Maximal voluntary exercise variables in children with postoperative coarctation of the aorta.

Thirty-one children with postoperative coarctation of the aorta underwent maximal graded bicycle ergometry using an electronically braked ergometer and the James protocol; 18 also underwent expiratory gas measurement using a mass spectrometer. Twenty-two age- and gender-matched normal subjects were used as a control group. The mean age at operation was 41 months and the mean age at evaluation was 134 months (mean follow-up interval 93 months). The original surgical repair was subclavian flap repair in 8 patients, end to end anastomosis in 21, patch aortoplasty in 1 patient and tubular graft in 1. Patients exercised until exhaustion and maximal exercise variables were obtained. The maximal voluntary peak heart rate was 183 beats/min (94.6% of predicted value), indicating excellent effort. Mean power was 111% of predicted value and, when measured, maximal oxygen consumption was 89% of predicted value with an anaerobic threshold at 63 +/- 3.5% of exercise time. The observed work variables were not different from values in the control group and were not affected by the type of repair. The mean peak systolic blood pressure was 152 +/- 7.6 mm Hg versus 147 +/- 5.7 mm Hg in the control group (p = NS). Patients who had associated intracardiac lesions had significantly lower maximal oxygen consumption (85 +/- 3% vs. 98 +/- 4% of predicted value). The results suggest that adequate cardiopulmonary function, normal or above average work capacity and normal exercise systolic blood pressure can be obtained in children with satisfactory repair of coarctation of the aorta performed before school age.

The St. Jude Medical cardiac valve in infants and children: role of anticoagulant therapy.

The experience at the University of Colorado with the St. Jude Medical cardiac valve was reviewed to determine the feasibility of placing this prosthesis in children and the role of anticoagulation. A St. Jude Medical cardiac valve was placed in 33 patients ranging in age from 2.5 months to 17 years. Seven patients were less than 1 year of age. Nineteen valves were placed in the aortic position in patients aged 5 months to 17 years (mean 9.5 years). Five patients had valve replacement only, 13 had concomitant aortoventriculoplasty and 1 a Manouguian procedure. Indications for anulus enlarging procedures were recurrent subaortic stenosis or inability to place an adult-sized valve in the native aortic anulus, or both. There were no early or late deaths. Fourteen valves were placed in the mitral position. They were anular positioned in 6 patients aged 6 months to 16 years and supraanular positioned in 8 patients aged 2.5 months to 2 years. There were no deaths with the anular positioned replacements and seven deaths (two early and five late) with the supraanular positioned replacements. Four of the five late deaths were associated with marked pre- and postoperative left ventricular dysfunction. The follow-up time was 784 patient-months in 31 long-term survivors. Anticoagulation was achieved with warfarin, usually in combination with sulfinpyrazone, dipyridamole or aspirin. There were four episodes of thromboembolism, three occurring in patients with suboptimal anticoagulation, and one in a patient lost to follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced UV Emission From Silver/ZnO And Gold/ZnO Core-Shell Nanoparticles: Photoluminescence, Radioluminescence, And Optically Stimulated Luminescence.

The optical properties of core-shell nanoparticles consisting of a ZnO shell grown on Ag and Au nanoparticle cores by a solution method have been investigated. Both the ZnO/Ag and ZnO/Au particles exhibit strongly enhanced near-band-edge UV emission from the ZnO when excited at 325 nm. Furthermore, the UV intensity increases with the metal nanoparticle concentration, with 60-fold and 17-fold enhancements for the ZnO/Ag and ZnO/Au, core-shell nanoparticles respectively. Accompanying the increase in UV emission, there is a corresponding decrease in the broad band defect emission with nanoparticle concentration. Nonetheless, the broad band luminescence increases with laser power. The results are consistent with enhanced exciton emission in the ZnO shells due to coupling with surface plasmon resonance of the metal nanoparticles. Luminescence measurements during and after exposure to X-rays also exhibit enhanced UV luminescence. These observations suggest that metal nanoparticles may be suitable for enhancing optical detection of ionizing radiation.

Pulmonary allograft conduit repair of tetralogy of Fallot. An alternative to transannular patch repair.

Cryopreserved allograft valves and valved conduits have been used in 122 patients during the past 3 years for surgical repair of congenital heart disease. In 55 of these patients, the right ventricular outflow tract was reconstructed with a pulmonary allograft conduit. Although most children requiring a conduit had complex lesions, 12 patients with tetralogy of Fallot without pulmonary atresia or absent valve syndrome have been treated in this manner since April 1985. Patients were selected for conduit therapy because of congenital or iatrogenic pulmonary artery problems (nine patients had 12 prior shunts) or increased pulmonary vascular resistance. Ages ranged from 7 months to 6 years (mean 3.1 years) and weights from 7.4 to 18.5 kg (mean 12.2 kg). Pulmonary artery conduit size ranged from 16 to 24 mm internal diameter (mean 22 mm). Distal pulmonary artery reconstruction beyond the bifurcation was required in nine patients and the proximal connection was completed with a hood-shaped patch. One operative death (8.3%) occurred at 20 days as a result of severe right ventricular dysfunction. Left pulmonary artery thrombosis was discovered postmortem. Eleven survivors observed for 3 to 37 months (mean 17 months) are without cardiac symptoms. A chronologically overlapping group of tetralogy of Fallot repairs accomplished with a transannular patch was also reviewed. Twenty-five patients aged 2 months to 4 years (mean 1.7 years) and weighing 3.6 to 14.8 kg (mean 9.2 kg) underwent this procedure from April 1983 to January 1987 (seven patients had one prior shunt each). The mortality rate in this group was 28% (six operative deaths and one late death). Of 18 survivors observed from 20 to 60 months (mean 41.4 months), five (28%) have required pulmonary artery conduit reconstruction for chronic right ventricular failure. Postrepair right ventricular/left ventricular pressure ratios were available in 19 patients, including five of seven who died and three of five who required reoperation. The ratios averaged 0.54, which indicates adequate relief of obstruction. The operative mortality rate from a number of series for transannular patch repair of tetralogy of Fallot averages 16%, ranging from 3% to 63%. However, when distal pulmonary artery problems are added as a risk factor this rate rises to 21%, and valved conduit insertion increases the mortality rate (Kirklin and Barratt-Boyes, 1986). Although not clearly superior, pulmonary artery conduit repair of tetralogy of Fallot achieves results comparable with those of transannular patch repair and is recommended as an alternative, particularly when distal pulmonary artery anatomy is abnormal or vascular resistance is elevated.

Surgical approach to critical pulmonary valve stenosis in infants less than six months of age.

During the past 7 1/2 years, 36 infants (less than or equal to 6 months of age) underwent surgical relief of critical pulmonary valve stenosis. The results of closed and open (cardiopulmonary bypass, CPB) procedures were compared. Closed procedures included Brock valvotomy (two patients) and normothermic inflow stasis with transpulmonary valvectomy (10 patients). Twenty-two patients had open procedures with valvectomy alone (five patients) and right ventricular outflow tract (RVOT) reconstruction (17 patients). Two additional patients had staged operations (shunt followed by open procedure at 3 and 5 months postoperatively). Patients who had the closed procedures, as compared with CPB, were significantly younger (10 versus 61 days, p less than 0.01) and more critically ill with congestive heart failure and acidosis. In addition, the mean peak systolic right ventricular-left ventricular pressure ratios (RVP/LVP) were higher (1.6 versus 1.4, p less than 0.02) in the closed group. There were no deaths in the closed group in contrast to six deaths among those having RVOT reconstruction (0/12 versus 6/17 or 35%, p less than 0.04). Critical obstruction of the pulmonary valve, tricuspid valve regurgitation, and hypoplastia of the right ventricle occurred more frequently in the closed group. All operative deaths resulted from right heart failure. There were no late deaths in the entire series. Three patients in the closed group (mean follow-up 2.8 years) required operations for recurrent pulmonary valve stenosis approximately 2 years postoperatively, and none in the open group (mean follow-up 2.0 years). In conclusion, despite current advances in infant CPB and care, the results from our experience suggests that closed procedures, especially inflow stasis and pulmonary valvectomy, are superior to the use of CPB and RVOT reconstruction, even in the presence of pulmonary valve dysplasia.

Conduit reconstruction of the right ventricular outflow tract. Lessons learned in a twelve-year experience.

From September 1979 to July 1991, a total of 163 patients have undergone valved conduit reconstruction of the right ventricular outflow tract when a right ventricle-pulmonary artery connection was absent or right ventricular outflow tract enlargement was required. From September 1979 through October 1984, 24 porcine valved conduits were implanted with an operative mortality of 38% (9/24). There were no early failures, but by 9 years after the operation 9 of 15 survivors (60%) had severe conduit obstruction, which resulted in death in 2 patients and reoperation in 6. From May 1985 to June 1991, 24 patients received cryopreserved aortic allografts to correct congenital anomalies. Operative mortality was 25% (6/24) and, again, early conduit function was good. There were 4 (22%) late deaths that were not related to the aortic allograft. At a mean follow-up of 3.4 years, 11 of the 13 survivors (85%) had allograft calcification and 8 of the 13 (62%) had mild to moderate conduit stenosis or regurgitation, or both; two of them required conduit replacement. Distal anastomotic problems that might have been avoided with bifurcated pulmonary allografts were apparent in 4 (36%) patients. Cryopreserved pulmonary allografts were placed in 115 patients between April 1985 and January 1991, with 18 (16%) operative deaths. Late deaths that were not allograft related occurred in 7 of 97 surviving patients (7%). Six patients (6%) underwent reoperation, 2 because of primary pulmonary allograft failure. The 84 remaining patients are free of symptoms with little or no allograft calcification or echocardiographic evidence of significant conduit stenosis or regurgitation. Experience with porcine valved conduits and aortic and pulmonary allografts suggests that pulmonary allografts are the conduit of choice for right ventricular outflow tract reconstruction.

Degeneration of aortic valve allografts in young recipients.

Aortic allograft fibrocalcification and valvular insufficiency have been observed in patients less than 3 years of age at initial replacement of the left ventricular outflow tract. From June 1985 through May 1992, 47 children have undergone aortic root replacement with cryopreserved aortic valve allografts. Thirty-three children were 3 years of age or older and 14 were less than 3 years of age at operation. In the older patient group, there were three (9%) hospital deaths and one child underwent cardiac transplantation 30 hours after aortic root replacement because of left ventricular failure. Clinical follow-up of the 29 surviving older children is from 4 months to 6.6 years (mean 3.0 years). One patient was lost to follow-up. Two children (7%) have required reoperation, but primary allograft degeneration was not observed. In the younger patient group, there were three (21%) hospital deaths. Follow-up ranged from 2.5 months to 4.7 years (mean 2.3 years). Among 11 operative survivors, one late death resulted from a pulmonary embolus. Seven of 10 (70%) remaining allograft recipients had progressive allograft calcification or insufficiency. Six of them have required reoperation to explant the allograft, and one child is currently receiving cyclosporine therapy with the original valve allograft. The cause of allograft failure is possibly immunologic. The prevalence of early aortic valve allograft degeneration has prompted the consideration of nonviable allografts or xenografts, pulmonary autografts, or minimal immunosuppression as alternatives when left ventricular outflow tract reconstruction is necessary in children less than 3 years of age.

Chylothorax and chylopericardial tamponade following Blalock-Taussig anastomosis.

A case of chylothorax following a right-sided Blalock-Taussig shunt is presented. Chylopericardial tamponade eventually developed, because the mediastinal leakage of chyle was sealed off from the pleural cavity and diverted into the pericardium. Chylopericardium is a rare cause of an enlarged cardiac silhouette on a postoperative chest roentgenogram, but the importance of differentiating it from congestive heart failure is illustrated. When chylopericardial tamponade occurs, treatment consists of (1) aspiration for immediate relief and, if there is recurrence, (2) surgical evacuation of the pericardium with tube drainage or pericardiectomy and (3) ligation of the source of chylous drainage.

Aortoventriculoplasty in children.

Aortoventriculoplasty was performed in 16 children between July, 1980, and July, 1984. Indications for the procedure were 1) aortic stenosis or insufficiency, or both, necessitating replacement of an aortic valve whose anulus would not accept a 19 mm diameter valve, (2) replacement of a small valve prosthesis, or (3) recurrent tunnel subaortic stenosis. Patients were 5 months to 17 years old at operation, 14 had previous repairs, and four had prior aortic valve replacement. There were 13 long-term survivors followed up for 14 to 38 months; 12 are asymptomatic with normal exercise tolerance. Three had residual ventricular septal defects, two requiring repair. All patients were given warfarin with or without antiplatelet agents. There have been no thromboembolic episodes and no hemorrhagic complications. Aortoventriculoplasty is well tolerated in children and appears to be a viable surgical option in the management of young patients with a hypoplastic left ventricular outflow tract.

Extended aortic root replacement with aortic allografts.

Complex left ventricular outflow tract obstruction after operation for subaortic stenosis or with hypoplastic aortic anulus remains a challenge for pediatric cardiac surgeons. We have recently applied a new technique of extended aortic root replacement using a cryopreserved aortic allograft to treat two patients who had previously been operated on for subaortic stenosis and a third who had aortic stenosis with a hypoplastic aortic anulus. This new procedure combines the concept of aortoventriculoplasty with aortic root replacement and coronary artery reimplantation. The valved aortic homograft is used in place of an aortic valve prosthesis and the attached anterior mitral leaflet augments the interventricular septum to relieve the subvalvular left ventricular outflow tract obstruction. The coronary ostia are then reimplanted into the allograft and an anastomosis between the distal graft and the ascending aorta is completed. Allograft aortic tissue is then used to patch the right ventricular outflow tract. One patient had aortic stenosis with annular hypoplasia and did well after extended root replacement. Two patients had previous operations for subaortic stenosis before undergoing extended aortic root replacement. One required mediastinal exploration and drainage at 2 weeks for Serratia marcescens mediastinitis and bacteremia, but uncomplicated recovery followed. The other patient had complete heart block for 2 days, but normal sinus rhythm resumed and convalescence was benign. This modified technique with the aortic allograft was very helpful in treating these difficult problems, and the lack of mortality, limited morbidity, and good functional results are encouraging.

Paralyzed left vocal cord associated with ligation of patent ductus arteriosus.

We reviewed the records of 167 neonates and older children undergoing ligation of a patent ductus arteriosus to determine the prevalence of recurrent laryngeal nerve injury and identify risk factors that might increase the likelihood of injury. Paralysis or paresis of the left vocal cord was identified by fiberoptic laryngoscopy in seven patients. All seven weighted less than 1500 gm at the time of operation and the ductus had been ligated with a metal clip. All had persistent symptoms when observed for 5 to 19 months. Injury to the left recurrent laryngeal nerve occurs infrequently but may have long-term consequences.

Cardiac 5'-nucleotidase activity increases with age and inversely relates to recovery from ischemia.

The metabolic basis for the enhanced tolerance of immature hearts to ischemia remains to be elucidated. Loss of high-energy phosphate nucleotides occurs during ischemia/reperfusion in mature (adult) hearts through the breakdown of adenosine triphosphate, diphosphate, and monophosphate (nondiffusible) to adenosine (freely diffusible). However, previous work has shown that after ischemia nondiffusible nucleotides are better retained by immature (neonatal) hearts than by mature hearts. The enzyme responsible for the conversion of adenosine monophosphate to adenosine is 5'-nucleotidase. We therefore hypothesized lower activity of this enzyme in neonatal than in adult myocardium. The purposes of this study were (1) to document 5'-nucleotidase activities in neonatal and adult rabbit myocardium and (2) to correlate differences of 5'-nucleotidase activity with functional recovery from ischemia. Neonatal (5- to 10-day-old) and adult (4- to 6-month-old) rabbit hearts were isolated and perfused (retrograde Langendorff). A left ventricular balloon measured functional parameters. Hearts were subjected to 20 minutes of global 37 degrees C ischemia and 10 minutes of reperfusion followed by freeze clamping. Tissue homogenates were assayed for 5'-nucleotidase by the linked formation of nicotinamide-adenine dinucleotide at 340 nm (Arkesteijn method). Postischemic recovery of developed pressure was 86% +/- 3% in neonates (n = 5) versus 38% +/- 3% in adults (n = 8) (mean +/- standard deviation) (p less than 0.01). 5'-Nucleotidase activity was 4400 +/- 1208 nmol/min/gm in neonates (n = 5) versus 13,938 +/- 830 nmol/min/gm in adults (n = 8) (mean +/- standard deviation) (p less than 0.01). We conclude that (1) 5'-nucleotidase activity is 68% lower in neonatal than in adult myocardium and (2) functional recovery after ischemia inversely relates to 5'-nucleotidase activity.

Infant heart transplantation: improved intermediate results.

OBJECTIVES: Our objectives were to (1) review our experience with heart transplants in infants (age < 6 months), (2) delineate risk factors for 30-day mortality, and (3) compare outcomes between our early and recent experience. METHODS: Records of all infants listed for transplantation in our center before September 1996 were analyzed. Early and recent comparisons were made between chronologic halves of the accrual period. Univariate analysis was used to analyze potential risk factors for 30-day mortality (categorical variables, Fisher's exact test; continuous variables, nonparametric Wilcoxon rank-sum test). Multivariable analysis included univariate variables with p values < or = 0.10. Actuarial survivals were estimated (Kaplan-Meier) and compared by the log-rank test. RESULTS: Fifty-one of the 60 infants listed for transplantation were operated on (waiting list mortality 15%). Thirty-day mortality was 18% overall, 30% in the first 3 years and 10% in the last 3 years (p = 0.07). Sepsis was the commonest cause of early death (4/9). Univariate analysis suggested four potential risk factors for early death: preoperative mechanical ventilation (p = 0.01), prior sternotomy (p = 0.002), preoperative inotropic drugs (p = 0.08), and warm ischemia time (p = 0.08). Multivariable analysis indicated that prior sternotomy (p = 0.01) was an independent risk factor for 30-day mortality. Actuarial survivals were 80%, 78%, and 70% at 1, 2, and 3 years, and these figures improved between early and recent groups (p = 0.05). Late deaths were most commonly due to acute rejection (3/5). CONCLUSIONS: Results of heart transplantation in infancy improve with experience. Prior sternotomy increases initial risk. Intermediate-term survival for infants with end-stage heart disease is excellent.

Prevention of erythrocyte adhesion onto porous surfaces by fluid perfusion.

This study was undertaken in order to investigate the use of fluid perfusion to prevent the adhesion of erythrocytes to a porous foreign surface. Three pore sizes each of two different commercially available polyethylene and aluminum oxide (AI2O3) tubes were investigated. Tubes were perfused with Ringer's solution while immersed in a bath of whole canine blood. Control tubes were prepared in an identical fashion but were not perfused. After testing, tubes were fixed in glutaraldehyde and dehydrated with graded ethanol. Samples were then sectioned and prepared for erythrocyte adhesion analysis by scanning electron microscopy (SEM). Results indicate that fluid perfusion can be used as a means to prevent erythrocyte adhesion in the range of pore sizes (10-60 micrometer diameter) studied. Critical values of the fluid perfusion rate are 0.027, 0.073 and 0.21 ml/min. cm2 for 10 micrometer, 35 micrometer, and 60 micrometer pore polyethylene respectively. The critical values for the ceramic samples are 0.22, 0.16 and 0.72 ml/min cm2 respectively for 7, 11 and 31 micrometer pore diameter respectively.

Mechanical and chemical consequences of the residual stresses in plasma sprayed hydroxyapatite coatings.

The residual stresses in thick hydroxyapatite coatings, deposited by plasma spraying, have been determined experimentally using Raman piezo-spectroscopy. The stress dependence of the centre position of the 980 cm 1 Raman band, owing to the symmetric stretching of the phosphate ion, PO3(4), has been established and found to be 2.47 cm 3 GPa 1. Using this calibration, the residual stresses in hydroxyapatite coatings deposited onto Ti-6A1-4V substrates in air have been found to be 100 MPa (tensile), whereas those deposited in a vacuum have been found to be 60 MPa (compressive). Although desirable from a mechanical point of view, it is shown that coating under residual compression are thermodynamically more stable and, hence, the dissolution of the ionic species, necessary in the exchange between bone and hydroxyapatite coating, can be impeded. It is calculated that for the coating under examination the stresses have an effect comparable with almost an order of magnitude change of the [OH] concentration. The analysis explains the dissolution behaviour of hydroxyapatite coatings subject to cyclic stress reported previously.

Extended aortic root replacement with cryopreserved allografts: do they hold up?

The extended aortic root replacement technique is used for the surgical repair of left ventricular outflow tract obstruction complicated by concurrent hypoplastic aortic annulus, multiple levels of obstruction, or aortic insufficiency. Extended aortic root replacement incorporates the concepts of aortic root replacement and aortoventriculoplasty to create a comparatively simple procedure. Unique features of the technique include the implantation of an allograft, which makes the need for anticoagulation obsolete, and use of the donor mitral leaflet to enlarge the outflow tract. Since 1985, 32 patients in Denver have undergone placement of a cryopreserved aortic valve allograft as part of extended aortic root replacement. There were four hospital deaths (13%), and 1 child underwent cardiac transplantation 30 hours after operation. In 6 months to 4.8 years of follow-up, a 14-year-old boy with familial hyperlipidemia required coronary artery bypass grafting, and 3 children experienced allograft calcification with progressive insufficiency, which prompted allograft replacement. The other 23 patients are clinically well.

Intraabdominal paddle placement for internal defibrillation during cardiac reoperation.

Ventricular fibrillation during sternal reentry can be a fatal complication that is vexing to manage when it occurs before complete exposure of the heart. A technique of intraabdominal paddle placement for internal countershock has been used to successfully manage this complication.