Is embolization of segment 4 portal veins before extended right hepatectomy justified?

Abstract

Background

Preoperative portal vein embolization (PVE) is increasingly used as a preparation for major hepatectomy in patients with inadequate liver remnant volume or function. However, whether segment 4 (S4) portal veins should be embolized is controversial. The effect of S4 PVE on the volume gain of segments 2 and 3 (S2+3) was examined.

Methods

Among 73 patients with uninjured liver who underwent right portal vein embolization (RPVE, n = 15) or RPVE extended to S4 portal veins (RPVE+4, n = 58), volume changes in S2+3 and S4 after embolization were compared. Clinical outcomes and PVE complications were assessed.

Results

After a median of 27 days, the S2+3 volume increased significantly after both RPVE and RPVE+4, but the absolute increase was significantly higher for RPVE+4 (median, 106 mL vs 141 mL; P = .044), as was the hypertrophy rate (median, 26% vs 54%; P = .021). There was no significant difference between RPVE and RPVE+4 in the absolute S4 volume increase (52 mL for RPVE vs 55 mL for RPVE+4; P = .61) or the hypertrophy rate of S4 (30% for RPVE vs 26% for RPVE+4; P = .45). Complications of PVE occurred in 1 patient (7%) after RPVE and 6 (10%) after RPVE+4 (P > .99). No PVE complication precluded subsequent resection. Curative hepatectomy was performed in 13 patients (87%) after RPVE and 40 (69%) after RPVE+4 (P = .21).

Conclusions

RPVE+4 significantly improves S2+3 hypertrophy compared with RPVE alone. Extending RPVE to S4 does not increase PVE-associated complications.

Preoperative portal vein embolization (PVE) was proposed by Makuuchi et al in 19901 to induce hypertrophy of the liver remnant. The procedure is increasingly used at major hepatobiliary centers and has contributed to expanded use of major hepatectomy in patients with initially insufficient liver remnant volume or function.2, 3, 4, 5 and 6

For patients with advanced cholangiocarcinoma in whom extended right hepatectomy is required, Nagino et al7 first introduced the concept of percutaneous transhepatic PVE with extension to the segment 4 (S4) portal veins (RPVE+4). The authors advocated this approach to optimize the hypertrophy of segments 2 and 3 (S2+3). We previously reported low mortality and morbidity (0.8% and 30.7%, respectively) after extended hepatectomy (resection of ≥5 liver segments) in a series of 127 patients, 31 of whom underwent RPVE+4 before resection.8 However, the appropriateness of RPVE+4 is controversial. Recently, Capussotti et al9 reported a similar volume increase in patients treated with RPVE and those treated with RPVE+4. These authors concluded that RPVE+4 should not be routinely performed because it is associated with a higher risk of migration of embolization materials to left portal vein branches.

Only a few previous studies have compared the change in volume of S2+3 after RPVE and RPVE+4.7 and 9 The aim of this study was to determine the effect of adding S4 embolization to RPVE on the gain in volume of S2+3 in the homogeneous subset of patients with normal liver. We retrospectively reviewed a large series of patients who underwent PVE at our institution over the past 9 years.