Subtotal splenectomy preserving the lower pole in rats: technical, morphological and functional aspects

Abstract

Purpose:To assess the possibility of preserving the lower pole of the spleen, supplied by the inferior lobar vessels and segmental vessels, or by vessels of the gastrosplenic ligament, in subtotal splenectomy; to study the viability and function of the lower pole of the spleen. Methods: Thirty-six male Wistar rats were used in this study. Said animals weighed 273-390 g ( 355.2 ± 30.5 g ), and were randomly distributed into three groups. Group 1 comprised ten animals which were submitted to exploratory laparotomy with spleen manipulation (sham operation). Group 2 comprised 16 animals which were submitted to total splenectomy. Group 3 comprised ten animals which were submitted to subtotal splenectomy, preserving the lower pole of the spleen. Blood was collected from all animals before and 90 days after surgery to measure the levels of cholesterol and triglycerides. The animals were sacrificed 90 days after surgery. Spleens and remaining spleens were removed for macroscopic and microscopic examination. Results: Surgery was performed with no complications in all groups. Six animals died in group 2. Spleens of groups 1 and 2, and lower poles of group 3 were macroscopically viable. Apparent white pulp hyperplasia was observed in group 1. In group 3, slight inflammation and capsular fibrosis were observed at the incision site, as well as diffuse hemosiderosis in the red pulp. Average mass of remaining spleen was 35.84% ± 4.31%. No significant difference was observed between preoperative and late postoperative lipid levels in groups 1 and 3 (p > 0.05). Late postoperative lipid levels significantly increased in group 2. Conclusions: Preservation of the lower pole of the spleen (supplied by gastrosplenic vessels or inferior lobar vessels and segmental vessels) was possible with subtotal splenectomy. The lower pole was macroscopically and microscopically viable in all cases. Subtotal splenectomy preserving the lower pole prevented changes in lipid levels, which were observed in rats submitted to total splenectomy. Plasma lipid levels in rats submitted to subtotal splenectomy were similar to those observed in sham operated rats. Key words: Spleen. Splenectomy. Rats. RESUMOObjetivo: Avaliar a exequibilidade de preservação do pólo inferior suprido por vasos lobares inferiores e segmentares ou por vasos no ligamento esplenogástrico, na esplenectomia subtotal, e estudar a viabilidade e a função desse pólo. Métodos: Foram utilizados 36 ratos machos, Wistar, com peso entre 273 gramas e 390 gramas (M.A 355,2 ±30,5), distribuídos aleatoriamente em 3 grupos : grupo 1-10 animais submetidos à laparotomia com manipulação do baço (operação simulada); grupo 2-16 animais submetidos à esplenectomia total ; grupo 3-10 animais submetidos à esplenectomia subtotal com preservação do pólo inferior. Em todos os animais foi colhido sangue no pré-operatório e no 90º P.O para dosagem do colesterol e frações e triglicérides. Os animais foram mortos após 90 dias e o baço e o remanescente esplênico foram retirados para estudo macro e microscó...

Late histological aspects of spleen autologous transplantation in rats

“…Thus, already a consensus exists among the authors that the greater omentum would be the place of ideal implantation, following by the mesenterium and mesocolon. This is due not only for its extension and vascularization, but, mainly, for its venous drainage to belong to the portal system, mimetizing the normal conditions of the spleen 22,25 .…”

“…Paulo et al 25 evaluated the technical, morphological and functional aspects of the inferior pole of the spleen of a group of 10 Wistar rats submitted to subtotal splenectomy. Other two groups had 10 animals submitted to laparotomy with spleen manipulation (sham operation) and 16 animals submitted to total splenectomy.…”

O pólo inferior do baço de ratos e a oxigenoterapia hiperbárica

“…Nos animais do grupo 1, foi realizada a manipulação do baço. Nos animais do grupo 2 (pólo inferior), foi realizada a esplenectomia subtotal com preservação do pólo inferior, mesmo com a ligadura dos vasos esplênicos principais, conforme técnica já descrita (Figura 1) 23 . A parede abdominal foi suturada em dois planos com mononáilon 4.0, chuleio simples.…”

“…Por essas razões têm sido valorizadas as operações conservadoras sobre o baço que compreendem as oclusões vasculares [12][13][14][15][16] , esplenorrafias 17 , esplenectomias parciais [18][19][20] e os auto-implantes 21,22 . Dessas, a mais recentemente descrita, em cães, foi a esplenectomia subtotal com preservação do pólo inferior, mesmo com a ligadura dos vasos esplênicos principais 23 . Nessa operação, observou-se aumento significante do colesterol e da fração LDL no pós-operatório mediato, e sugeriu-se a possibilidade de isquemia do pólo inferior remanescente.…”

Preservative spleen surgery and hyperbaric oxygen therapy

“…3,4 Besides these, alterations in lipid metabolism following splenectomy have been reported in human subjects 5 and experimental animals 6,7,8 , capable of causing atherosclerosis. 6 For these reasons, conservative spleen operations including vascular occlusions 9,10 , splenorrhaphies 11 , partial splenectomies 12,13,14 and auto-implants. 15,16 have been valorized.…”