[The feasibility and safety of radiofrequency ablation for secondary splenomegaly and hypersplenism in dogs].

OBJECTIVE

To assess the feasibility and safety of radiofrequency ablation (RFA) in spleen to treat secondary splenomegaly and hypersplenism in dogs.

METHODS

Fourteen healthy mongrel dogs were randomly divided into two groups: group A (n = 4) and group B (n = 10) Both groups underwent ligation of the splenic vein and its collateral branches to induce congestive splenomegaly. At the end of the 3rd week, radiofrequency thermal ablation of the spleen was performed in the group B via laparotomy. After splenic RFA, the procedure-related complications were observed, CT scan was performed and the spleens were obtained according to schedule. The radiofrequency (RF) thermal lesions and its histo- pathological changes of the spleen were examined regularly.

RESULTS

There were no morbidity and mortality in the experimental dogs. CT findings revealed that splenomegaly could sustained over 2 months after ligation of the splenic vein. The segmental RF lesions included hyperintense zone of coagulative necrosis and more extensively peripheral hypo-intense infarcted zone. The latter was called as "bystander effect". The infarcted zone would be absorbed and subsequently disappeared between 4 and 6 weeks after RFA, and the size of the remnant spleen shrunk, but the lesion of coagulative necrosis hardly altered. The fundamental histopathological changes of splenic lesions caused by RF thermal energy included local coagulative necrosis and the peripheral thrombotic infarction zone. Subsequently, tissue absorption and fibrosis occurred in the zone of thrombotic infarction. Simultaneously occluded vessels, fibrin deposition, and disappearance of normal splenic sinuses resulted in the condensed structure of the viable remnant spleen, which were the pathological basis responsible for the shrunk spleen.

CONCLUSIONS

It is feasible and safe to perform RFA in the spleen to treat experimental splenomegaly and hypersplenism. The RFA technique could be safely performed clinically via laparotomy or laparoscopic procedure to strictly isolate the spleen from the surrounding organs.