Tissue Engineering of Vascular Prosthetic Grafts Using Autogenous Vein Cells

PURPOSE: To investigate bioartificial vessels capable of being used for vascular grafts, we studied cell-polymer constructs from venous smooth muscle cells (SMCs) and biodegradable scaffolds using the canine model. METHODS: Scaffolds constructed from 50/50 poly (D,L-Lactide-co-glycolide) (PLGA) were created with pores containing gelatin particles. Disk type scaffolds were used as templates of cell attachment and vascular tissue regeneration. SMCs were isolated from canine external jugular veins and primary SMCs cultures were produced with the explant-derived method. SMCs were seeded into the scaffolds and cultured statically for 4 weeks. The cell-polymer constructs were examined histochemically and using scanning electron microscopy. RESULTS: The SMCs obtained by the explant-derived method were confirmed with immunohistochemical staining using an anti-smooth muscle actin antibody. Four weeks after the SMCs were seeded into the scaffold, histological examination showed SMCs infiltration into the scaffold wall and scanning electron microscopy revealed the SMCs mass which resembled tissue on the scaffold surface. CONCLUSION: This is a pilot study for the constructing artificial vessels using tissue engineering. The construction of the ideal scaffold for vessel and the improvement of culture methods in vitro are the most important parts in this field.

Evaluation of Prognosis in Esophageal Atresia

The aims of this study were to evaluate the prognostic predictabilities of the risk classifications (Waterston, Montreal, and Spitz), preoperative treatment of pneumonia and the length of esophageal gap in esophageal atresia. Twenty-five cases of esophageal atresia were reviewed retrospectively. The data was analyzed with Likelihood ratio test for trend and Fisher's exact test. Survival rates were 100.0% in group A and B, and 60.0% in group C according to Waterston classification (p=0.027). By Montreal classification, 95.7% in group I and 50.0% in group II (p=0.086). By Spitz classification, 95.5% in group I and 66.7% in group II (p=0.159). The survival rate was 85.7% in the patients with pneumonia preoperatively treated and 94.4% in the patients without pneumonia. The difference was not significant (p=0.490). Survival rate in the patients with long gap (> or = 3cm) was 50.0% and 100.0% in patients with short gap (< 3cm) with significant difference (p=0.020). The Waterston classification could be modified into two groups because the prognosis of both group A and B were the same. Preoperative pneumonia does not seem to be a risk factor. The length of the esophageal gap showed prognostic value.