[Enlargement of the internal thoracic artery with intact vascular wall structure by construction of an arterio-venous shunt].
The purpose of this investigation was to examine whether construction of an arterio-venous shunt could enlarge the internal thoracic artery (ITA) and preserve normal structure of the vascular wall. Five mongrel dogs were used. Side-to-side anastomosis was made between the left ITA and left internal thoracic vein. These dogs were followed for about 6 weeks and diameters of bilateral ITAs were determined by angiography. The diameter of the left ITA was 2.67 +/- 0.5mm, which was significantly larger than the right ITA (2.24 +/- 0.4mm, as control, p < 0.01). The right to left ITA ratio was 119.4 +/- 6.9%. There was no significant difference in the morphologic features of endothelial cells between left and right ITAs. Several specimens of the left ITA showed morphologic changes of protruding nucleus, widening of intercellular junctions and creater formation. There was no significant difference between the ITAs with respect to thickness of media and the number of elastic fibers in the media. The smooth muscle cells just under the internal elastic lamina didn't appear to be synthetic phenotype. In conclusion, arterio-venous shunting enlarged the diameter of ITA, and caused minimum morphologic change in the intima and media.
Koyanagi
T
T
Department of Cardiovascular Surgery, Heart Institute of Japan, Tokyo Women's Medical College, Japan.
D000714:Anastomosis, Surgical / Q000379:methods; D000818:Animals; D001166:Arteriovenous Shunt, Surgical / Q000379:methods; D004106:Dilatation / Q000379:methods; D004285:Dogs; D004547:Elastic Tissue / Q000473:pathology; D013895:Thoracic Arteries / Q000473:pathology / Q000601:surgery*; D017539:Tunica Intima / Q000473:pathology