Paul Laeseke, Presenter: Nothing to Disclose

Lisa Ann Sampson, Abstract Co-Author: Nothing to Disclose

Tina M Tatum, Abstract Co-Author: Nothing to Disclose

Christopher L Brace, Abstract Co-Author: Nothing to Disclose

Thomas Charles Winter MD, Abstract Co-Author: Nothing to Disclose

Fred T. Lee MD, Abstract Co-Author: Nothing to Disclose

Inadvertent collateral injury to non-targeted tissue is a limiting factor for all thermal ablation modalities. This is particularly true as zones of ablation increase in size. Recently, 5% dextrose in water (D5W) has been proposed to provide a thermal and electrical buffer. In this study, we evaluated the ability of 0.9% saline and D5W to protect adjacent bowel from thermal damage during radiofrequency (RF) ablation of the liver.

A total of 20 RF ablations were performed in four domestic swine livers using a Cool-tip™ generator and cluster electrodes (Valleylab, Boulder, CO). Twelve-minute ablations were performed in three groups: 1) no protective fluid (n=8), 2) peritoneal 0.9% saline (n=6) or 3) peritoneal D5W (n=6). RF probes were placed superficially below the liver capsule with colon applied directly to the liver surface or offset by 2.7 mm by a hollow vinyl spacer filled with saline or D5W. Zones of ablation were excised and corresponding bowel segments resected. Ablation zone size and surface area of thermal injury to the liver and bowel were measured and ratios of bowel-to-liver surface injuries were compared between groups.

Mean (± SD) areas of damage to the bowel wall were 20.4±8.4 cm2 (no protection) 9.63±3.6 cm2 (D5W) and 7.69±6.4 cm2 (saline) while ratios of bowel-to-liver surface injury for each group were 1.12±0.4 (no protection), 0.65±0.3 (D5W) and 0.52±0.3 (saline). Animals in the D5W and saline groups experienced significantly less bowel injury after ablation when compared to no protection (P=.028 and P<.01, respectively). There was no significant difference between the saline and D5W groups for protective effect (P=.46).

Thermal damage was markedly reduced after an infusion of D5W or saline when compared to no protection. The use of these fluids may allow for more aggressive treatment of tumors in close proximity to bowel. While no significant difference was observed between saline and D5W in this study, previous studies suggest a more pronounced protective effect with D5W, likely due to the inability of non-ionic D5W to conduct electricity.

F.T.L.: member of advisory board at Valleylab

Laeseke, P, Sampson, L, Tatum, T, Brace, C, Winter, T, Lee, F, RF Ablation in the Abdomen: Protecting Bowel from Thermal Injury with 5% Dextrose in Water.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4419148.html