Temporary targeted renal blood flow interruption using a reverse thermosensitive polymer to facilitate bloodless partial nephrectomy: a swine survival study.

Unlabelled: What's known on the subject? and What does the study add? Lumagel™ is a reverse thermosensitive polymer (RTP) that has previously been described in the literature as providing temporary vascular occlusion to allow for bloodless partial nephrectomy (PN) while maintaining blood flow to the untargeted portion of the kidney. At body temperature, Lumagel™ has the consistency of a viscous gel but upon cooling rapidly converts to a liquid state and does not reconstitute thereafter. This property has allowed for it to be used in situations requiring temporary vascular occlusion.

Feasibility of bloodless liver resection using Lumagel, a reverse thermoplastic polymer, to produce temporary, targeted hepatic blood flow interruption.

Background:   Lumagel, a reverse thermosensitive polymer (RTP), provides targeted flow interruption to the kidney by reversibly plugging segmental branches of the renal artery, allowing blood-free partial nephrectomy. Extending this technology to the liver requires the development of techniques for temporary occlusion of the hepatic artery and selected portal vein branches.

Methods:   A three-phased, 15 swine study was performed to determine feasibility, techniques and survival implications of using Lumagel for occlusion of inflow vessels to targeted portions of the liver.

Targeted endovascular temporary vessel occlusion with a reverse thermosensitive polymer for near-bloodless partial nephrectomy: comparison to standard surgical clamping techniques.

Purpose: To determine whether reversible blood flow interruption to a randomly chosen target region of the kidney may be achieved with the injection of a reverse thermoplastic polymer through an angiographic catheter, thereby facilitating partial nephrectomy without compromising blood flow to the remaining kidney or adding risks beyond those encountered by the use of hilar clamping.

Methods: Fifteen pigs underwent partial nephrectomy after blood flow interruption by vascular cross-clamping or injection of polymer (Lumagel™) into a segmental artery. Five animals were euthanized after surgery (three open and two laparoscopic resection, cross-clamping n = 2), and 10 (open resection, cross-clamping n = 4) were euthanized after 6 weeks' survival.

Temporary targeted hemostasis to facilitate bloodless partial nephrectomy.

Objective: To extend previous robotic-assisted techniques developed in the swine model to studies of laparoscopic and open partial nephrectomy conducted in pigs and calves, designed to encompass vessel diameters similar to those encountered in humans. Lumagel (Pluromed, Woburn, MA), a nontoxic polymer, can be administered intra-arterially under fluoroscopic guidance to obtain a bloodless operative field during partial nephrectomy while maintaining normal circulation to uninvolved renal tissue.

Methods: A total of 10 animals (7 pigs and 3 calves) underwent flow interruption to the kidney, 2 with cross-clamping of the main renal artery, the remaining with Lumagel.

Endovascular temporary vessel occlusion with a reverse-thermosensitive polymer for bloodless minimally invasive renal surgery.

Purpose: To demonstrate the feasibility of reversible vessel embolization with angiographic guidance for delivery of a rapid reverse-thermosensitive polymer to provide hemostasis as an aid for minimally invasive renal surgery in a porcine model.

Materials And Methods: After isolation of the left kidney of seven anesthetized pigs (50-70 kg) with a surgical robot, a renal angiogram of both kidneys was obtained. A 5-F angiographic catheter was used to selectively embolize a lower-pole segmental artery of the right and left kidney with a thermosensitive polymer (LeGoo-XL).

Temporary segmental renal artery occlusion using reverse phase polymer for bloodless robotic partial nephrectomy.

Purpose: Renal vascular clamping with ensuing warm ischemia is typically needed during robotic or laparoscopic partial nephrectomy. We developed a technique for angiographic delivery of the novel intra-arterial reverse thermoplastic polymer LeGoo-XL that allows temporary selective vascular occlusion with normal perfusion of the remaining kidney.

Materials And Methods: Eight pigs underwent a total of 16 selective angiographic occlusions of the lower pole segmental artery using gel polymer.

Management of thrombophilia in renal transplant patients.

Renal allograft recipients with thrombophilia (a hypercoagulable state) are at higher risk for early allograft loss. Following an episode of allograft renal vein thrombosis in a patient subsequently diagnosed with protein C deficiency, we adopted universal screening for hypercoagulable risk factors. Patients with a history of a thromboembolic event underwent laboratory screening for thrombophilia.