Date: 30 Aug 2012
Determination of the Nonlethal Margin Inside the Visible “Ice-Ball” During Percutaneous Cryoablation of Renal Tissue
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.Get Access
The study was designed to determine the distance between the visible “ice-ball” and the lethal temperature isotherm for normal renal tissue during cryoablation.
The Animal Care Committee approved the study. Nine adult swine were used: three to determine the optimum tissue stain and six to test the hypotheses. They were anesthetized and the left renal artery was catheterized under fluoroscopy. Under MR guidance, the kidney was ablated and (at end of a complete ablation) the nonfrozen renal tissue (surrounding the “ice-ball”) was stained via renal artery catheter. Kidneys were explanted and sent for slide preparation and examination. From each slide, we measured the maximum, minimum, and an in-between distance from the stained to the lethal tissue boundaries (margin). We examined each slide for evidence of “heat pump” effect.
A total of 126 measurements of the margin (visible “ice-ball”–lethal margin) were made. These measurements were obtained from 29 slides prepared from the 6 test animals. Mean width was 0.75 ± 0.44 mm (maximum 1.15 ± 0.51 mm). It was found to increase adjacent to large blood vessels. No “heat pump” effect was noted within the lethal zone. Data are limited to normal swine renal tissue.
Considering the effects of the “heat pump” phenomenon for normal renal tissue, the margin was measured to be 1.15 ± 0.51 mm. To approximate the efficacy of the “gold standard” (partial nephrectomy, ~98 %), a minimum margin of 3 mm is recommended (3 × SD). Given these assumptions and extrapolating for renal cancer, which reportedly is more cryoresistant with a lethal temperature of −40 °C, the recommended margin is 6 mm.
Grant Support: Financial support from Siemens Medical Solutions, USA, Inc.
Ljunberg B, Campbell S, Cho H et al (2011) The epidemiology of renal cell carcinoma. Eur Urol 60(4):615–621CrossRef
National Cancer Institute. Surveillance Epidemiology and End results. http://seer.cancer.gov/statfacts/html/kidrp.html
Kauk J, Aron M, Rewcastle J et al (2006) Cryotherapy: clinical end points and experimental foundations. Urology 68(Suppl 1A):38–44CrossRef
Clarke D, Robilotto A, Rhee E et al (2007) Cryoablation of renal cancer: variables involved in freezing-induced cell death. Technol Cancer Res Treat 6(2):69–79PubMed
Williams SK, de la Rosette J, Landman J, Keely FX (2007) Cryoablation of small renal tumors. EAU-EBU Update Series 5:206–218
Antonelli A, Ficarra V, Bertini R et al (2012) Elective partial nephrectomy is equivalent to radical nephrectomy in patients with clinical T1 renal cell carcinoma: results of a retrospective, comparative, multi-institutional study. BJU Int 109(7):1013–1018
- Determination of the Nonlethal Margin Inside the Visible “Ice-Ball” During Percutaneous Cryoablation of Renal Tissue
CardioVascular and Interventional Radiology
Volume 36, Issue 3 , pp 783-790
- Cover Date
- Print ISSN
- Online ISSN
- Additional Links
- Ablation margin
- Kidney cancer
- Industry Sectors
- Author Affiliations
- 1. Department of Vascular & Interventional Radiology, Interventional Radiology Center, Johns Hopkins University, Sheikh Zayed Tower, Suite 7203, 1800 Orleans Street, Baltimore, MD, 21287, USA
- 2. Department of Urology, Johns Hopkins University, Baltimore, MD, USA
- 3. Department of Urologic Pathology, Johns Hopkins University, Baltimore, MD, USA