The visceral perfusion system and distal bypass during thoracoabdominal aneurysm surgery: an alternative for physiological blood flow?

There are potential benefits to addition of visceral organ perfusion, by me ans of a 9-Fr. catheter system (octopus), to distal aortic perfusion during thoracoabdominal aneurysm surgery, However, in the literature there are re ports of adverse effects. The authors therefore compared two groups of pati ents who underwent thoracoabdominal aneurysm surgery with and without visce ral organ perfusion. In the group in which the Visceral perfusion was appli ed, the use of platelets (26 versus 11 units; P < 0.05), fresh frozen plasm a (3.4 versus 1.5 units; P < 0.05) and packed cells (20 versus 8 units, P < 0.05) was significantly increased. An equal number of patients in both gro ups developed renal failure postoperatively, An explanation for this advers e effect can be found in the high shear rates in the catheters used, mainly as a result of the small diameter, High shear rates cause haemolysis, Also , the flow through the catheters is insufficient to maintain adequate perfu sion of the visceral organs. A higher flow in these catheters would result in an even higher shear rate. It is therefore concluded that coagulopathy a nd insufficient bloodflow is caused by the small internal diameter of the c atheters, which renders the device insufficient. (C) 1999 The International Society for Cardiovascular Surgery, Published by Elsevier Science Ltd. All rights reserved.