Preoperative Portal Vein Embolization in Hepatic Surgery: A Review about the Embolic Materials and Their Effects on Liver Regeneration and Outcome

Abstract

Liver volume and function after hepatectomies are directly correlated to postoperative complications and mortality. Consequently contemporary liver surgery has focused on reaching an adequate future liver remnant so as to diminish postoperative morbidity and mortality. Portal vein embolization has evolved and is the standard of care as a liver regenerative strategy in many surgery departments worldwide before major liver resections. Different embolic materials have been used for portal vein embolization including gelfoam, ethanol, polyvinyl-alcohol particles, calibrated microspheres, central vascular plugs, coils, n-butyl-cyanoacrylate glue, fibrin glue, polidocanol-foam, alcoholic prolamin solution, and ethylene vinyl alcohol copolymer, as sole occluders or in varied combinations. While to date there has been no prospective controlled trial comparing the efficacy of different embolic materials in portal vein embolization, retrospective data insinuates that the use of n-butyl-cyanoacrylate and absolute ethanol produces higher contralateral liver hypertrophies. In this review, we evaluated publications up to August 2019 to assess the technical and regenerative results of portal vein embolization accomplished with different embolic materials. Special attention was given to specific aspects, advantages, and drawbacks of each embolic agent used for portal vein embolization, its liver regenerative performance, and its influence on patient outcome.

Figure 1

Final portography aspect after portal vein embolization with NBCA accomplished through a contralateral portal vein access.

Figure 2

Final portography aspect after portal vein embolization with PVA plus coils accomplished through an ipsilateral portal vein access.

Figure 3

Portal vein embolization accomplished with PVA plus coils. Fluoroscopy image shows the first coil (a) and the last coil (b) deployed in a right portal vein embolization.

Figure 4

Portal vein embolization accomplished with NBCA and lipiodol with a 1:5 ratio. The green arrow shows the liver tract embolization from the ipsilateral approach.

Figure 5

(a and b). Catheter used for portal vein embolization with absolute alcohol. This 5 French catheter has an end hole for ethanol administration, a side hole for contrast flushing, and an in-between balloon to prevent alcohol reflux (reprinted with permission from the American Journal of Roentgenology). (c). The triple lumen catheter (white arrow heads) with the balloon inflated is placed in the right portal vein. The black arrows refer to a nasobiliary drain. (d). Portography with the balloon inflated shows the anterior sectorial branch, which was embolized with absolute alcohol through the end hole (reprinted with permission from the American Journal of Roentgenology).

Figure 6

(a) Computed tomography in the portal venous phase acquired before portal vein embolization shows a small left liver (future liver remnant circled in black line). (b) Computed tomography in the portal venous phase shows a significant increase in the left liver (future liver remnant circled in black line) 28 days after portal vein embolization with NBCA.