From baby to man with a piggyback heart: long-term success of heterotopic heart transplantation.

We present a case of a young man, who underwent heterotopic heart transplantation 20 years ago, when he was 6 months old. The baby suffered from severe intractable cardiomyopathy. In this desperate situation only a miniature, compromised donor heart became available. Today, the young man is fully active under minimal immunosuppression. His surgical course is reviewed and described.

Composition and in vitro biocompatibility of corroding tungsten coils.

The purpose of the article is to evaluate composition and biocompatibility of corroding mechanically detachable spirals (MDS, Balt Extrusion, Montmorency, France). Analysis of the material composition of corroding MDS coils was assessed by inductively coupled plasma atomic emission spectroscopy, inductively coupled plasma mass spectroscopy, and wavelength-dispersive x-ray spectrometry. Toxicity assays were performed with human venous endothelial cells, venous smooth muscle cells and fibroblasts. The analyses of the MDS coils demonstrated a tungsten content of the dissolving MDS spirals of > 99.9 mas%. In vitro, human endothelial, vascular smooth muscle cells and fibroblasts were not adversely affected by markedly elevated tungsten concentrations (60,500 microg/l) after 12 days in the culture medium. The examined cells showed an extensive vital growth on the coil surface. Corrosion of tungsten coils leads to markedly elevated tungsten levels in the culture medium. However, growth and vitality of endothelial cells, fibroblasts, and vascular smooth muscle cells are not adversely affected by elevated tungsten concentrations.

Dissolution of tungsten coils does not produce systemic toxicity, but leads to elevated levels of tungsten in the serum and recanalization of the previously occluded vessel.

AIM: To evaluate the failure of mechanically detachable spirals produced from tungsten (MDS, Balt, Montmorency, France) and the toxicity of elevated levels of tungsten in the serum subsequent to their implantation. METHODS: We reviewed findings in 21 patients in whom tungsten coils had been used to occlude pathologic vessels, aneurysms and fistulas between 1996 and 1999. We achieved clinical follow-up, and measured renal and hepatic function, in 14 of the 21 patients. RESULTS: Decreased radiopacity of the coils was observed in 9 of 13 patients who had follow-up fluoroscopy during repeat cardiac catheterization. Repeat angiography of the vessel occluded by the coil was performed in 7 patients, 5 of whom showed recanalization. Levels of tungsten in the serum were analyzed 6 to 35 months after implantation of coils in 8 patients. The mean concentration was 6.43 micrograms/l, with a range from 2 to 14.4 micrograms/l, normal values being less than 0.2 microgram/l. CONCLUSION: Tungsten coils may dissolve over time and lead to markedly elevated levels of tungsten in the serum, with recanalization of previously occluded vessels. Despite lack of clinical and laboratory data in patients with elevated levels of tungsten in the serum, our study suggests that the clinical use of mechanically detachable coils produced from tungsten should no longer be recommended.

Fontan-type procedures: residual lesions and late interventions.

BACKGROUND: The purpose of this study was to determine the type and incidence of hemodynamic and electrophysiological abnormalities requiring surgical or catheter-based interventions in a single-center long-term experience. METHODS: Eighty-eight patients with a follow-up of at least 5 years (mean follow-up, 9.6 +/- 2.6 years) after Fontan-type procedures were included. All patients had undergone cardiac catheterization either as part of the regular postoperative protocol or because of symptomatic atrial tachycardia or increasing cyanosis. RESULTS: Freedom from reoperation for up to 5 years was documented for 82% of patients and decreased to 76% after 8 years. Late reoperations included conversion of an atriopulmonary anastomosis to a total cavopulmonary anastomosis in 2 patients with atrial dysrhythmia and implantation of an extracardiac conduit in 1 patient with left atrial isomerism and intrapulmonary arteriovenous malformations after a Kawashima operation. Decline in sinus node function with symptomatic bradycardia required pacemaker therapy in 10 patients (11%). Transcatheter interventions included fenestration occlusion in 5 of the 11 patients with initial baffle fenestration. In 6 of 17 patients with aortopulmonary collaterals, coil occlusion was indicated to reduce future systemic ventricular volume load. Various systemic venous collaterals were documented in 11 patients and required coil occlusion in 2. One patient with symptomatic protein-losing enteropathy underwent transcatheter fenestration creation without sustained relief of symptoms. Freedom from transcatheter interventions decreased from 94% to 82% after 5 and 10 years, respectively. CONCLUSIONS: During long-term follow-up, reoperations are rare and mainly involve Fontan conversion to either a lateral-tunnel or extracardiac-conduit procedure. Detailed angiographic evaluation on a routine basis allows identification of the vascular sites of origin of aortopulmonary collateral vessels and systemic venous collaterals potentially developing during long-term follow-up. Transcatheter interventions including fenestration occlusion and occlusion of venous collaterals and aortopulmonary collaterals were performed to maintain and improve the Fontan circulation in clinically symptomatic and asymptomatic patients. During long-term follow-up after Fontan-type operations, a regular postoperative cardiac catheterization protocol is recommended.

Anterograde balloon valvuloplasty for the treatment of neonatal critical valvar aortic stenosis.

We report our experience with anterograde balloon valvuloplasty in 17 neonates treated between November 1996 and June 2001 for critical aortic stenosis. Patients with hypoplastic left heart syndrome were excluded. Anterograde balloon valvoplasty of the aortic valve was possible in all 17 patients. The mean peak systolic gradient prior to cardiac catheterization was 73 mm Hg (range, 30-117 mm Hg) and decreased to 37 mm Hg (range, 21-60 mm Hg) after the dilation. Aortic regurgitation after balloon valvoplasty was absent or mild in 14/17 patients, moderate in 2 patients, and severe in 1 patient. There was no mortality or echocardiographic evidence for aortic cusp perforation or mitral regurgitation associated with the procedure. Redilation was necessary in 3/17 patients. Two patients are awaiting elective Ross operation. One patient with endocardial fibroelastosis died at 11 months of age. Anterograde balloon valvoplasty can be safely and effectively performed to palliate neonates with critical aortic valve stenosis.

Simultaneous cytometric analysis of (auto)antigen-reactive T and B cell proliferation.

The detection and characterization of (auto)antigen-specific lymphocytes, both B and T cells, is essential to investigate immunopathologic mechanisms. Our aim was to perform a CFSE (Carboxyfluorescein diacetate succinimidyl ester)-based cytometric analysis of peripheral blood mononuclear cells (PBMC) proliferating in response to antigenic provocation. CFSE-labeled PBMC were stimulated with a superantigen (SEB), a recall antigen (tetanus toxoid), an allergen (grass pollen) and an autoantigen (nucleosomes) and stained after cultivation with CD4-, CD8- and CD19-antibodies. Proliferated cells were identified cytometrically by the decrease of the CFSE fluorescence intensity due to cell division. Antigen-reactive, proliferated B cells were further analysed phenotypically, antigen-specific proliferated Th cells were further characterized functionally regarding their cytokine secretion pattern after polyclonal restimulation. Using this technique, antigen-specific proliferated B and Th cells were detected even at low frequencies. Analyzing the cytokine secretion pattern of allergen-reactive proliferated Th cells after polyclonal restimulation we found differences in the expression of IL-13 and IL-4 between an atopic and a healthy donor. After stimulation of PBMC from TT-vaccinated donors TT-specific proliferated B cells were detected in high frequencies and showed a plasmablast-typical CD20(low) CD27(high) phenotype with only low frequencies expressing CD138 (= Syndecan-1). Proliferation of nucleosome-reactive Th cells and B cells was observed in both patients and healthy controls. We have optimized here the cytometric analysis of reactive cell proliferation based on CFSE offering various facilities of application on the further characterization of both antigen-specific B and T cells.

Experimental ASD closure using autologous cell-seeded interventional closure devices.

OBJECTIVE: Atrial septal defect (ASD) occluders are permanent implants in paediatric cardiology which serve as mechanical shields until complete overgrowth and incorporation of the occluding device by autologous tissue has occurred. Thereafter, the foreign body material making up the device is dispensable and bears potential long-term adverse effects. Rapid, firm and complete incorporation into the atrial septal wall should be a prerequisite for biodegradable devices. In this study, the feasibility of using autologous cell-seeded devices was investigated by (a) testing the influence of a collagen coating on cellular stress resistance in vitro and (b) comparing the short-term effects between cell-seeded, collagen-coated and acellular ASD occluders in vivo. METHODS: Native and collagen-coated Dacon fabrics and Starflex-devices were pre-seeded with autologous fibroblasts (skin biopsy) and evaluated using various mechanical stress tests. In a sheep model interventionally created ASDs were closed using either autologous pre-seeded or conventional (acellular) Starflex-devices. RESULTS: ASD closure devices were successfully pre-seeded with autologous cells. The incubation period needed, the cellular density achieved and the mechanical stability of the cytolayer after mechanical stressing (implantation) were improved by applying a collagen matrix on the fabric. Compared to the thin layer of ingrown tissue seen on conventional occluders after 30 days in vivo, a thicker layer of organising, newly formed granulation tissue on pre-seeded collagen-coated devices embedded not only the Dacron fabric, but also completely covered the spring arms of the device underneath a layer of neo-endothelium. CONCLUSION: Autologous cell pre-seeding of interventional closure devices is feasible since the cells survive the mechanical stress encountered during implantation. Rapid, firm and complete ingrowth of occluder devices into a thicker layer of young fibrous granulation tissue can be achieved, but an increased thrombogenicity currently limits the in vivo application.