In vitro, ex vivo and in vivo isotherms for renal cryotherapy.
Title | In vitro, ex vivo and in vivo isotherms for renal cryotherapy. |
Publication Type | Journal Article |
Year of Publication | 2010 |
Authors | Young, J. L., Kolla S. B., Pick D. L., Sountoulides P., Kaufmann O. G., Ortiz-Vanderdys C. G., Huynh V. B., Kaplan A. G., Andrade L. A., Osann K. E., Louie M. K., McDougall E. M., & Clayman R. V. |
Journal | J Urol |
Volume | 183 |
Issue | 2 |
Pagination | 752-8 |
Date Published | 2010 Feb |
ISSN | 1527-3792 |
Keywords | Animals, Cryosurgery, Equipment Design, Kidney, Swine |
Abstract | PURPOSE: Preoperative planning for renal cryotherapy is based on isotherms established in gel. We replicated gel isotherms and correlated them with ex vivo and in vivo isotherms in a porcine model.MATERIALS AND METHODS: PERC-17 CryoProbes (1.7 mm) and IceRods (1.47 mm) underwent trials in gel, ex vivo and in vivo porcine kidneys. Temperatures were recorded at 13 predetermined locations with multipoint thermal sensors.RESULTS: At the cryoprobe temperatures were not significantly different along the probe in any medium for either system (p = 0.0947 to 0.9609). However, away from the probe ex vivo and in vivo trials showed warmer temperatures toward the cryoprobe tip for each system (p = 0.0003 to 0.2141). Mean +/- SE temperature 5 mm distal to the cryoprobe tip in vivo was 19.2C +/- 16.1C for CryoProbes and 27.3C +/- 11.2C for IceRods. Temperatures were consistently colder with CryoProbes than with IceRods in gel (p <0.00005), ex vivo (p <0.00005) and in vivo (p = 0.0014). At almost all sites temperatures were significantly colder in gel and in ex vivo kidney than in in vivo kidney for CryoProbes (p = 0.0107 and 0.0008, respectively) and for IceRods (each p <0.00005).CONCLUSIONS: Gel and ex vivo isotherms do not predict the in vivo pattern of freezing. Thus, they should not be used for preoperative planning. The cryoprobe should be passed 5 mm beyond the tumor border to achieve suitably cold temperatures. Multipoint thermal sensor probes are recommended to record actual temperature during renal cryotherapy. |
DOI | 10.1016/j.juro.2009.09.072 |
Alternate Journal | J Urol |
PubMed ID | 20022060 |