Renal Subcapular Saline Injection during Percutanoues Renal Cryoablation to Prevent Bowel Injury
Sompol Permpongkosol MD*,**, Theresa L Nicol MD***, Frederico R Romero MD*, Soroush Rais-Bahrami MD*, Niwat Aranyakasemsuk MD*, Stephen B Solomon MD****, Louis R Kavoussi MD*****
Affiliation : * Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA ** Department of Surgery, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand *** Department of Pathology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA **** Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, USA ***** Institute for Urology, North Shore-LIJ Health System, Long Island, New York, USA
Introduction: To evaluate the feasibility of percutaneous injection of saline in the renal subcapsular space to
prevent bowel injury and histopathologic effects of bowel cryolesion during renal cryoablation in a porcine
model.
Material and Method: Six pigs underwent percutaneous renal cryoablation with two freeze cycles in the
lower pole of both kidneys. Six kidneys were injected with 10 ml saline into the renal subcapular space before
cryoablation. The bowel was brought into contact with the edge of the ice ball with laparoscopic assistance
during renal cryoablation, on the side with saline injection as well as on the control side. One of these animals
was kept for survival follow-up and laparotomy for 7 days post cryoablation. The bowel cryolesion sites were
observed and compared based on the presence or absence of renal subcapsular saline injection.
Results : The mean diameter of acute bowel injury with and without saline renal subcapsular injection was
7.25 + 1.26 and 14.5 + 0.58 mm, respectively. The influence of injecting a saline buffer, was a significant
decrease in the bowel cryolesion compared to controls (p = 0.0003). In addition, a pig kept for follow-up
confirmed no bowel perforation after 7 days at a site that was cryolesioned on the side with renal subcapsular
saline injection, but sustained bowel perforation in another segment lesioned by contact with a kidney
without a saline injection. Gross and microscopic pathological examination was consistent with these inter-
pretations.
Conclusion : Preliminary results in a porcine model show that percutaneous renal subcapsular saline injection
is a feasible and promising technique for preventing bowel complications of percutaneous image-guided
renal cryoablation.
Keywords : Percutaneous renal cryoablation, Bowel injury, Subcapuar, Saline injection
