Sebastian Flacke MD, Presenter: Research Consultant, Pluromed, Inc

Ali Moinzadeh, Abstract Co-Author: Nothing to Disclose

Jim A Benn, Abstract Co-Author: Employee, Pluromed, Inc

Niall Harty, Abstract Co-Author: Nothing to Disclose

John A Libertino MD, Abstract Co-Author: Nothing to Disclose

Peter Madras, Abstract Co-Author: Employee, Pluromed, Inc

Aarti Kalra, Abstract Co-Author: Nothing to Disclose

To determine if reversible blood flow interruption to a randomly chosen target region of the kidney can be provided with the injection of a thermoplastic polymer through an angiographic catheter to facilitate its resection without compromising the blood flow to the remaining kidney or adding risks beyond those encountered by the use of hilar clamping.

15 pigs underwent partial nephrectomy after blood flow interruption by vascular cross clamping (n=6) or injection of a reversible thermosensitive polymer (Lumagel TM) into a segmental artery. The polymer transitions from liquid at low temperature to viscous gel at higher temperature; the rapid transformation occurs at approximately 14 ˚C. The polymer mass reverts back to a liquid with cooling as the heat induced miscellation of the copolymer is reversed allowing the monomer to disperse in flowing blood and to be excreted unmetabolized in urin. 5 animals were euthanized following surgery (3 x open and 2 x laparoscopic resection), 10 (open resection) after 6 weeks survival. Blood specimen were obtained throughout, a repeat angiogram and a complete necropsy at six weeks. 

Selective renal ischemia was achieved in all cases. Surgical resection time averaged 11 minutes (range 10-13) and 23.3 (range 9-40) in the open and laparoscopic groups, respectively. Estimated blood loss was negligible with the exception of one case where an accessory renal artery was originally overlooked. Reversal of the polymer to a liquid state was consistent angiographically and visually in all cases. Time to complete flow return averaged 7 and 2.5 minutes for Lumagel™ and arterial clamping, respectively. Angiographic analysis at six weeks did not demonstrate any evidence of vascular injury. Laboratory data and necropsies showed no differences between animals undergoing vascular clamping or polymer injection.

Lumagel was as effective as vascular clamping in producing a bloodless operative field for partial nephrectomy while maintaining flow to the uninvolved portion of the affected kidney. 

Avoiding temporary ischemia of the unaffected portion of the kidney during partial nephrectomy using a polymer injection to create hemostasis may preserve better renal function of the kidney remnant.

Flacke, S, Moinzadeh, A, Benn, J, Harty, N, Libertino, J, Madras, P, Kalra, A, Targeted Endovascular Temporary Vessel Occlusion with a Reverse Thermo-sensitive Polymer for Bloodless Partial Nephrectomy: Comparison to Standard Surgical Clamping Techniques .  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11007919.html