Evaluation of risk of splenosis during laparoscopic splenectomy in rat model

Laparoscopic splenectomy (LS) is an alternative to open surgery. However, there is a theoretic risk of splenosis and abdominal cavity dissemination of splenic cells if the splenic capsule is broken, as seen by experimental evidence of tumoral cell mobilization by the pneumoperitoneum. We evaluated the features of splenosis after splenectomy operated via an open approach or under laparoscopic control in an experimental model in the rat. A total of 65 Sprague-Dawley rats were distributed in seven groups that included the open approach, CO2 pneumoperitoneum LS, or wall lift LS with or without a splenic graft. Splenic function was evaluated 90 day later through (1) scintigraphy with Tc-labeled heat-damaged erythrocytes; (2) determination of circulating "pitted" cells; and (3) analysis of the distribution of splenic pulp in the peritoneal cavity. Scintigraphy did not show viable residual tissue in any group after splenectomy; splenic activity in the splenic fossa was observed in 40% of the animals with grafts. Splenectomy increased the "pit" cell count, but it was reduced to normal values with a splenic graft. Necropsy showed normal splenic tissue in the splenic fossa in 100% of animals with a graft. Abdominal implants were observed significantly more frequent after CO2 LS than after the open surgery or a wall lift LS (80% vs. 20% vs. 30%; p < 0.05). In addition, trocar site implants were observed with CO2 LS (n = 3) or wall lift LS (n = 2), whereas there were no implants in the wound in the open group. We conclude that in an experimental rat model the pneumoperitoneum may facilitate abdominal splenosis after LS if the splenic capsule is ruptured or if splenic tissue spills compared with surgery without gas (open or laparoscopic).