Percutaneous cryoablation of porcine kidneys with magnetic resonance imaging monitoring.
OBJECTIVE
We determined the feasibility of a percutaneous approach using magnetic resonance imaging (MRI) for creating cryoablation lesions in the porcine kidney.


METHODS
Three domestic swine underwent renal cryoablation under MRI guidance with a total of 6 cryoablation lesions created in 5 kidneys. A 3 mm. cryoprobe was placed under MRI guidance using an interventional MRI unit. With a pressurized argon gas cooling unit the cryoablation lesion was created and monitored by MRI. Gross and histological examination of the kidneys was performed 1 week after the procedure.


RESULTS
All animals survived the procedure without difficulty. A total of 6 cryoablation lesions were produced in 5 kidneys. The lesions were 1.9 x 1.3 to 3.9 x 1.9 cm. on MRI. Histological examination 1 week after treatment showed that the lesions were 1.7 x 1.0 to 3.2 x 1.2 cm. There was an area of coagulation necrosis surrounded by a transition zone of inflammatory reaction a mean of 0.5 cm. in diameter with each lesion.


CONCLUSIONS
Percutaneous renal cryoablation using MRI imaging proved to be a successful technique for guiding probe placement and monitoring ice ball formation. Because MRI allows imaging in 3 planes, it may be useful for cryoablation of intraparenchymatous tumors.
Shingleton
W B
WB
Division of Urology, Department of Surgery, University of Mississippi Medical Center, Jackson, Mississippi, USA.
Farabaugh
P
P
Hughson
M
M
Sewell
P E
PE
D000818:Animals; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods*; D007668:Kidney / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D016343:Monitoring, Intraoperative / Q000379:methods; D012680:Sensitivity and Specificity; D013552:Swine