ABSTRACT
<p><b>OBJECTIVE</b>To study the anatomy of the small intestine,and investigate the optimal selection of donors,recipients,and their small intestine vessels in piglet small intestine transplantation.</p><p><b>METHODS</b>The weight and length of 30 piglets were measured. Angiography and pigments perfusion were used to observe the main vessels of the small intestine,and the length of the small intestine,and the external diameter of the main vessels of the small intestine were measured in vivo and ex vivo.</p><p><b>RESULTS</b>The length of the small intestine was 11.5 times as long as the body length, and its weight accounted for 2.3% of the body weight. The outer diameters of abdominal aorta (AT), mesenteric anterior artery (MAA) and its 5(th)-6(th) branches in vivo and ex vitro were 4.3/4.6mm, 2.5/2.7mm and 1.9/2.2mm respectively. The total number of MAA's branches was 6-8 in general and its 5(th)-6(th) branches were the longest [(20.0 +/- 7.0) mm, (22.0 +/- 8.2) mm]. The outer diameter of mesenterial anterior vein (MAV) was 1-2 mm wider than that of MAA.</p><p><b>CONCLUSIONS</b>AT, MAA and its 5(th)-6(th) branches are the preferable vessels for small intestine transplantation. In segmental small intestine transplantation, the length of the small intestine and body weight can be used to primarily select the suitable animals.</p>