Perfusion and functional anatomy of the splenic remnant supplied by short gastric vessels

BACKGROUND: Surgeons have described many methods to preserve the injured spleen for the maintenance of host defence. The volume and the perfusion of remaining splenic tissue are important for better functional results. Imaging the functioning tissue with radionuclide provides information about the physiology of the concerning organ. METHODS: Thirty rats were separated into three groups: control, explorative laparotomy alone; partial splenectomy, upper part of the spleen supplied by short gastric vessels was preserved after partial resection; and devascularized spleen, the entire spleen was preserved after ligation of splenic artery. The size, functional anatomy, and perfusion status of splenic tissue were assessed by liver-spleen scintigraphy using radiolabeled heat denatured red blood cells. RESULTS: In the partial splenectomy group, splenic radioactivity count, spleen/liver ratio, and radionuclide uptake were mildly reduced, and found to be 87% (P = 0.012), 91% (P = 0.16), and 88% (P <0.001) of the normal spleen, respectively. The area of functional tissue in the upper splenic remnant was 51% (P <0.001) of the normal spleen. In the devascularized spleen group, the radioactivity count, the ratio, and the uptake were 38% (P <10(-6)), 36% (P <10(-6)), and 49% (P <10(-6)) of the normal spleen respectively. The area of functional tissue in the devascularized spleen was calculated as 47% (P <10(-6)) of the normal spleen. CONCLUSIONS: The collateral circulation is insufficient for proper function of the entire spleen after disconnection of the main arterial blood supply. The functional tissue is markedly impaired. On the other hand, the upper part of the spleen is remained well perfused via the short gastric vessels. The collateral circulation is satisfactory for this splenic tissue after reduction of its volume. That size splenic tissue seems to have satisfactory functional ability. Proper functional results mostly depend on the balance between the volume and blood supply of the remaining splenic tissue.