Effectiveness of different coils for endovascular coiling for intractable hepatic encephalopathy caused by a portosystemic shunt

Background: Interventional radiology (IVR), including balloon-occluded retrograde transvenous obliteration (BRTO) and percutaneous transhepatic obliteration (PTO), is performed for patients with intractable HE. However, information on the appropriate coil for endovascular coiling for preventing recanalization is lacking. This study aimed to compare the different types of coils for endovascular coiling used in BRTO and PTO for cases of intractable HE. Methods: This retrospective study included patients who underwent endovascular coiling with BRTO or PTO for HE caused by portosystemic shunts. The number of coils required for complete occlusion was compared among bare, fiber, and hydrogel-coated coils, and the expansion types that close the gap between and inside the hydrogel-coated coils were also compared. Results: Of 38 patients (age range, 30-86 years), 16 and 22 underwent BRTO and PTO, respectively, using bare (19 patients), fiber (8 patients), and hydrogel-coated coils (10 patients; external expansion type, 4; internal expansion type, 6). No significant differences in the size of portosystemic shunts were observed according to the type of coil. The mean number of coils required for complete occlusion varied (bare coils, 19.32; fiber coils, 18.11; hydrogel-coated coils, 10.70). Significantly fewer coils were required for endovascular coiling with hydrogel-coated coils. In the internal expansion type, a mean of 8.5 coils was required for occlusion. Conclusions: In some patients who underwent portal vein embolization, complete occlusion was not achieved with the scheduled type of coil because of slight expansion of blood vessels due to coil pressure. The findings suggested that hydrogel-coated coils were effective in endovascular coiling for HE caused by a portosystemic shunt, and internal expansion-type hydrogel-coated coils may be effective for the first-line procedure.