Minimal vascular flows cause strong heat sink effects in hepatic radiofrequency ablation ex vivo.

Minimal vascular flows cause strong heat sink effects in hepatic radiofrequency ablation ex vivo.

J Hepatobiliary Pancreat Sci. 2016 Jun 23;

Authors: Lehmann KS, Poch FG, Rieder C, Schenk A, Stroux A, Frericks BB, Gemeinhardt O, Holmer C, Kreis ME, Ritz JP, Zurbuchen U

Abstract
PURPOSE: To assess the lower threshold of vascular flow rate on the heat sink effect in bipolar radiofrequency ablation (RFA) ex vivo.
METHODS: Glass tubes (vessels) of 3.4 mm inner diameter were introduced in parallel to bipolar RFA applicators into porcine liver ex vivo. Vessels were perfused with flow rates of 0 to 1,500 ml/min. RFA (30 W power, 15 kJ energy input) was carried out at room temperature and 37 °C. Heat sink effects were assessed in RFA cross sections by the decrease in ablation radius, area and by a high-resolution sector planimetry.
RESULTS: Flow rates of 1 ml/min already caused a significant cooling effect (p ≤ 0.001). The heat sink effect reached a maximum at 10 ml/min (18.4 mm/s) and remained stable for flow rates up to 1,500 ml/min.
CONCLUSIONS: Minimal vascular flows of ≥ 1 ml/min cause a significant heat sink effect in hepatic RFA ex vivo. A lower limit for volumetric flow rate was not found. The maximum of the heat sink effect was reached at a flow rate of 10 ml/min and remained stable for flow rates up to 1,500 ml/min. Hepatic inflow occlusion should be considered in RFA close to hepatic vessels.

PMID: 27338856 [PubMed - as supplied by publisher]

from Radiofrequency (RF) ablation via xlomafota13 on Inoreader http://ift.tt/298djsB


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/28YIMkD
via IFTTT