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

Abstract

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. Lumagel was delivered using angiographic techniques to sites determined by pre-operative 3-D vascular reconstructions of arterial and venous branches. During resection, the targeted liver mass was resected without vascular clamping. Three survival swine were sacrificed at 3 weeks; the remainder at 6 weeks for pathological studies.

Results: Six animals (100%) survived, with normal growth, blood tests and no adverse events. Three left lateral lobe resections encountered no bleeding during resection; one right median resection bled; two control animals bled significantly. Pre-terminal angiography and autopsy showed no local pathology and no remote organ damage.

Conclusions: Targeted flow interruption to the left lateral lobe of the swine liver is feasible and allows resection without bleeding, toxicity or pathological sequelae. Targeting the remaining liver will require more elaborate plug deposition owing to the extensive collateral venous network.

Figure 1

Three-dimensional reconstruction of the portal venous circulation of a typical swine. Note the single dominant portal vein. Each colour represents a different segment

Figure 2

Digital subtraction portal venography before and after deposition of the Lumagel Plug. Gel plugs can be programmed to dissolve spontaneously or dissolved with a cold saline injection

Figure 3

Liver resection without vascular clamps. Arrow shows Lumagel in the orifice of the cut portal vein branch

Figure 4

Liver section at the cut margin, hematoxylin and eosin (H&E) stain, 20×. No pathological features from Lumagel instillation. Note normal portal venous branch (Arrow)