Growth of the lower spleen pole remaining after subtotal splenectomy in rats

To determine whether the lower pole of the spleen grows after subtotal splenectomy following ligature of major spleen blood vessels. Thirty-nine Wistar rats (328.8 +/- 27.8 g) submitted to subtotal splenectomy with preservation of the lower splenic pole were divided into two groups: group 1 (control, n=20), immediate removal of the lower pole; group 2 (n=19), removal of the pole on postoperative day 80. The length, width and thickness of the pole were measured. In the control group, mean percent pole weight was calculated immediately after surgery in a direct and indirect manner. In the first case, the weight of the lower pole was divided by overall spleen weight; in the second case, pole weight was divided by the ideal weight of the spleen obtained by linear regression analysis. The results of the two calculations were compared. Macro- and microscopic examinations of the pole were performed. In group 1, no significant difference in mean percent pole weight was observed between the direct and indirect method. In group 2, mean percent pole weight obtained by indirect calculation on day 80 was higher than in group 1 (p