Does Down syndrome affect the long-term results of complete atrioventricular septal defect when the defect is repaired during the first year of life?

BACKGROUND: Down syndrome is known to affect the natural history of complete atrioventricular septal defect. We analyzed whether Down syndrome affect the long-term results of complete atrioventricular septal defect when the defect is repaired during the first year of life. METHODS: Repairs of complete atrioventricular septal defect were performed in 64 infants. Thirty-four infants were associated with Down syndrome, while the other 30 were non-Down patients. RESULTS: Complete follow-up rate was 95% with mean follow-up period of 99+/-47 months (maximum 169 months) in Down patients and 80+/-64 months (maximum 213 months) in non-Down patients. There was one operative death in each group (mortality rate of 2.9% in Down patients and 3.3% in non-Down patients), and three patients died at the late phase (one in Down patients and two in non-Down patients). Five patients underwent re-operation due to postoperative left atrioventricular valve regurgitation (one in Down patients and four in non-Down patients). Freedom from re-operation for left atrioventricular valve regurgitation and actuarial survival rate at 13 years were 96+/-4 and 94+/-4% in Down patients and 85+/-7 and 90+/-5% in non-Down patients (not significantly different). CONCLUSIONS: Down syndrome does not affect the long-term results of complete atrioventricular septal defect when the defect is repaired during the first year of life.

Canine endothelial progenitor cell-lined hybrid vascular graft with nonthrombogenic potential.

OBJECTIVE: We sought to fabricate a compliant engineered vascular graft (inner diameter of approximately 4.5 mm and length of 6 cm) lined with endothelial progenitor cells derived from circulating peripheral canine blood and to verify its nonthrombogenicity potential in vivo. METHODS: Autologous circulating endothelial progenitor cells derived from the peripheral veins of 6 adult mongrel dogs were isolated by using a density gradient method. The cells were proliferated in vitro in EGM-2 culture medium, prelined on the luminal surface of in situ-formed collagen type I meshes as an extracellular matrix, and wrapped with a segmented polyurethane thin film with multiple micropores as a compliant scaffold. After canine carotid arteries were bilaterally implanted with these grafts for 1 and 3 months, microscopic observation, histologic staining, and immunochemical staining were performed to evaluate morphogenesis. RESULTS: After 33.3 +/- 10.5 days of culture in vitro, 4.2 +/- 1.2 x 10(6) endothelial progenitor cells were obtained. Eleven of the 12 engineered vascular grafts were patent. The grafts possessed smooth, glistening, and ivory-colored luminal surfaces at the predetermined observation period up to 3 months. The intimal layer was covered with confluent, cobblestone-like monolayered cells that were positively stained with factor VIIIB-related antigen. The thickness of the neoarterial walls was approximately 300 microm at 3 months after implantation. A few smooth muscle cells were observed in the medial tissue, and fibroblasts dominated the adventitial tissue. CONCLUSION: Circulating endothelial progenitor cells could be a substitute source of endothelial cells for endothelialization on small-diameter-vessel prostheses to ensure nonthrombogenicity.

Intralumenal tissue-engineered therapeutic stent using endothelial progenitor cell-inoculated hybrid tissue and in vitro performance.

Rapid reendothelialization at an atherosclerotic lesion after balloon or stent inflation may be essential for maintaining homeostatic tissue function, which could reduce or prevent restenosis. We devised an endothelial progenitor cell (EPC)-enriched tubular hybrid tissue and mounted it on a small-diameter metallic stent (outer diameter, 1.5 mm), which is used for intravascular angioplasty to atherosclerotic lesions. This study addressed the fabrication technique and in vitro performance to verify lumenal endothelialization. A thin collagenous tubular tissue was prepared by contraction of collagen fibers by inoculated EPCs, which were isolated from canine peripheral blood and expanded ex vivo, in a collagen gel formed in a mold. An EPC-inoculated hybrid tissue-covered stent, loaded on a balloon catheter, was inserted into a tubular hybrid vascular medial tissue inoculated with smooth muscle cells (SMCs) as an arterial media mimic, and subjected to balloon inflation for enlargement (outer diameter, 3 mm), followed by balloon deflation. The EPC-inoculated hybrid tissue-covered stent tightly adhered to the lumenal surface of the hybrid medial tissue. On culture, EPCs in the hybrid tissue migrated and proliferated to form a completely endothelialized lumenal surface at stented sites as well as sites adjacent to the vascular hybrid medial tissue with the prolongation of culture. This in vitro pilot study before in vivo experiments suggests that an EPC-inoculated hybrid tissue-covered stent may be a novel therapeutic device for reendothelialization or paving with EPC-enriched tissue at an atherosclerotic arterial wall, resulting in the prevention of restenosis and the rapid formation of normal tissue.

Fabrication of endothelial progenitor cell (EPC)-seeded intravascular stent devices and in vitro endothelialization on hybrid vascular tissue.

Rapid re-endothelialization at an atherosclerotic lesion after balloon inflation or stent deployment may be essential for reducing or preventing local thrombus formation and restenosis. In order to prevent these complications via enhanced rapid re-endothelialization, we fabricated two types of endothelial progenitor cell (EPC)-seeded intravascular stent devices. One was a photocured gelatin-coated metallic stent, and the other was a microporous thin segmented polyurethane (SPU) film-covered stent on which photocured gelatin was coated. Both devices were seeded with ex vivo expanded EPCs obtained from canine peripheral blood. Seeded EPCs formed confluent monolayers onto surfaces of both photocured gelatin-coated stent struts and SPU film, and a majority of cells remained on surfaces of stents after stent expansion. The EPC-seeded stent was expanded in a tubular hybrid vascular medial tissue composed of vascular smooth muscle cells and collagen as an arterial media mimic. After 7-day culture, EPCs, which migrated from the stent struts, proliferated and endothelialized the luminal surfaces of the hybrid vascular medial tissue. This in vitro pilot study prior to in vivo experiments suggests that on-stent cell delivery of EPCs may be novel therapeutic devices for re-endothelialization or endothelium lining or paving at an atherosclerotic arterial wall, resulting in the prevention of on-stent thrombus formation and in-stent restenosis, as well as the rapid formation of normal tissue architecture.

Human endothelial progenitor cell-seeded hybrid graft: proliferative and antithrombogenic potentials in vitro and fabrication processing.

In this article, we show that human endothelial progenitor cells (EPCs) in circulating peripheral blood may be a novel cell source for a cell-incorporated engineered vascular graft. Cultures of human peripheral blood mononuclear cells collected by the density gradient technique developed highly proliferative EPC colonies, which expanded with culture time. The production rates of antiplatelet substances such as endothelial-type nitric oxide synthase and 6-keto-prostaglandin-F(1)-alpha were approximately one-third and approximately one-half of those of mature endothelial cells (ECs), respectively. On the other hand, the tissue-type plasminogen activator production rate of EPCs was almost the same as that of ECs. EPCs were seeded and cultured on a small-diameter compliant graft (inner diameter, 1.5 mm) made of microporous segmented polyurethane film coated with a photo-reactive gelatin layer, and subsequently subjected to hydrodynamic shear stress by ex vivo circulation. EPCs fully covering the graft elongated and aligned themselves with the direction of the flow, resulting in the production of an integrated EPC-engineered graft. These results indicate that EPCs, which have high proliferative potential and high antithrombogenic potential, comparable to those of ECs, are a suitable cell source for cardiovascular tissue engineering.

Case of a bleeding pseudoaneurysm of the middle colic artery complicating acute pancreatitis.

Massive bleeding from a pseudoaneurysm is rare, but it can be a life-threatening complication in patients with acute pancreatitis. We present a case in which massive bleeding from a pseudoneurysm in the middle colic artery complicating acute pancreatitis was successfully treated by transcatheter embolization and by continuous regional arterial infusion of a protease inhibitor and antibiotic. We also discuss the clinical features, diagnosis and treatment of such lesions in light of the literature. We emphasize the value of computed tomography in the early diagnosis of mesenteric hematoma in cases of acute pancreatitis and the value of angiography for control of bleeding from the complicating pseudoaneurysm.