Intraluminal irradiation for TIPS stenosis: preliminary results in a swine model.
OBJECTIVE
To evaluate the ability of 32phosphorus intraluminal irradiation to reduce pseudointimal hyperplasia in a transjugular intrahepatic portosystemic shunt (TIPS).


METHODS
TIPS were successfully placed in 11 swine with normal portal pressures. Six animals received 15.2 Gy intraluminal irradiation to the hepatic parenchyma and venous outflow tract at the time of TIPS placement with use of a NA32P-filled balloon angioplasty catheter. Five control animals underwent TIPS and balloon angioplasty with saline. All animals were followed up for 28 days, at which time percutaneous portography was performed, the animals were killed, and the tissue around the TIPS stent was processed for histologic analysis. Maximum pseudointimal hyperplasia as a percentage of estimated TIPS diameter was calculated for each animal.


RESULTS
At the time of euthanasia, all five control TIPS and all but one irradiated TIPS were occluded. Histologic analysis demonstrated considerable variability in the degree of pseudointimal hyperplasia within each TIPS and between animals. No statistically significant difference was found in the maximum pseudointimal hyperplasia, measured as a percentage of stent radius, between control (80.2%+/-17.4%) and irradiated animals (69.2%+/-25.2%).


CONCLUSIONS
Irradiation of TIPS with 15.2 Gy 32P delivered at the time of TIPS placement did not significantly improve TIPS patency or reduce the degree of pseudointimal hyperplasia in swine with normal portal pressures.
Lessie
T
T
Department of Radiology, University of Utah School of Medicine, Salt Lake City 84132, USA.
Yoon
H C
HC
Nelson
H A
HA
Fillmore
D J
DJ
Baldwin
G N
GN
Miller
F J
FJ
D000800:Angioplasty, Balloon; D000818:Animals; D003251:Constriction, Pathologic / Q000532:radiotherapy; D006503:Hepatic Veins / Q000473:pathology / Q000528:radiation effects*; D006965:Hyperplasia; D008099:Liver / Q000473:pathology / Q000528:radiation effects; D010761:Phosphorus Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use*; D011169:Portal Vein / Q000473:pathology / Q000528:radiation effects*; D019168:Portasystemic Shunt, Transjugular Intrahepatic; D011172:Portography; D011879:Radiotherapy Dosage; D015607:Stents; D013552:Swine; D017539:Tunica Intima / Q000473:pathology / Q000528:radiation effects
D010761:Phosphorus Radioisotopes