Splenic resection or heterotopic transplantation of splenic tissue as alternatives to splenectomy. Regeneration and protective effect against pneumococcal septicemia.

In 82 male Sprague-Dawley rats, divided into eight groups according to surgical procedure performed (total splenectomy, sham operation and six different modes of splenic conservation), resistance to intravenous injection of 4 X 10(3) CFU of Streptococcus pneumoniae type I was evaluated 16 weeks after the surgical procedures. Significant regeneration of the spleen and almost normal resistance to pneumococci was seen 16 weeks after a two-thirds resection. Pieces of the spleen, implanted subcutaneously or into the greater omentum, also showed marked regeneration; though survival time was prolonged, the mortality among these animals following injection with pneumococci did not, however, differ from that of totally splenectomized animals. Dispersed splenic tissue, injected subcutaneously, intramuscularly, or retroperitoneally, showed less sign of regeneration and had no effect on mortality or survival time in partially vis-à-vis totally splenectomized rats.