Toshiyuki Matsuoka MD, Presenter: Nothing to Disclose

Akira Yamamoto MD, Abstract Co-Author: Nothing to Disclose

Tomohisa Okuma MD, Abstract Co-Author: Nothing to Disclose

Kenji Nakamura MD, Abstract Co-Author: Nothing to Disclose

Yoshimasa Oyama MD, Abstract Co-Author: Nothing to Disclose

Masami Toyoshima MD, Abstract Co-Author: Nothing to Disclose

Ryusaku Yamada, Abstract Co-Author: Nothing to Disclose

Yuichi Inoue MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Partial splenic embolization (PSE) is performed as a treatment for such as thrombocytopenia caused by hypersplenism. However, PSE is often accompanied with high fever and severe flank pain, and an abscess becomes serious complication at time. On the other hand, percutaneous radiofrequency ablation (RFA) is expected as a less invasive therapy in various organs. The aim of this study is to assess the feasibility of CT-guided RFA of spleen as a minimally invasive method.

The technique was tested in six pigs. Using general anesthesia, all pigs were punctured with expandable LeVeen Needle of 2cm diameter under CT guidance. After confirmation of the needle position not to damage bowel, ablation was performed till tissue being coagulated at three or four places of spleen on one pig. Output was started at 30 watts and elevated gradually. The maximum output did not exceed 50 watts. Blood samples were collected before procedures. An extent of ablated area and adverse events were observed by contrast-enhanced CT after the procedure. To evaluate changes with time, blood collection and contrast-enhanced CT were done 2, 4 and 8 weeks later.

Procedures were easy and successful in all pigs. The route which seemed to pass lung parenchyma or to damage bowel could be avoided by using CT. Tissue coagulation was achieved in 2 min. 24 sec.- 8 min. 45 sec. (3 min. 49 sec. on average) in 17 procedures except one which needed 14 min. 10 sec. No subcapsular or retroperitoneal hematoma was observed in all procedures. All pigs were well after having come out of anesthesia. Ablated areas were seen as a non-enhanced area of 2.5-3cm diameter each. They occupied 15-20% of the whole spleen after the procedure and reduced in size with time. As for the numbers of platelet, an average of 10% increased four weeks later and returned to pre RFA value eight weeks later.

Percutaneous RFA of spleen is technically feasible in the pig. Less complications are expected by using CT. Although further study is necessary, this method seems to have a potential to be a minimally invasive alternative to PSE.

Matsuoka, T, Yamamoto, A, Okuma, T, Nakamura, K, Oyama, Y, Toyoshima, M, Yamada, R, Inoue, Y, et al, , CT-guided Splenic RFA: A Preliminary Study.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4407036.html