Outflow modulation to target liver regeneration: something old, something new.
BACKGROUND
Stimulation of hepatic hypertrophy is a useful aid to accomplish hepatic resections when the future liver remnant (FLR) is small. Although inflow occlusion, especially through portal flow, has been extensively studied, the role of outflow modulation has not yet been described.


METHODS
Description of outflow modulation to tailor hypertrophy of future liver remnant in the context of bilobar metastatic disease. A patient with small FLR (segments I and IV) was managed with a two-stage procedure. The first stage consisted of a right hepatectomy and modulation of the left hepatic vein outflow through reduction of its diameter, with macroscopic congestion of segments II-III. The second stage consisted of a left lateral sectionectomy six weeks later. Postoperative courses were uneventful without any sign of liver failure.


RESULTS
Following the first stage procedure computed tomography revealed distinct hypertrophy rates between sections. The non-congested area had an increase of 156% in the volume of segment IV (from 137 to 351 cm(3)) and 100% in the volume of segment I (from 20 to 40 cm(3)). The congested area, segments II-III, increased only 24% (from 205 to 253 cm(3)).


CONCLUSIONS
Modulation of liver outflow allows maintenance of function in the segments to be resected while avoiding their hypertrophy. This process prevents liver failure and optimizes regeneration of hepatic territories to be preserved.
Department of Surgery, Moinhos de Vento Hospital, Porto Alegre, Brazil; University of Santa Cruz do Sul (UNISC), Santa Cruz do Sul, Brazil; Oncological Center of Ana Nery Hospital and Saint Gallen Institute of Oncology, Santa Cruz do Sul, Brazil. Electronic address: sbalzan@hotmail.com.
S M P
SM
Balzan
Department of Surgery, Moinhos de Vento Hospital, Porto Alegre, Brazil; University of Santa Cruz do Sul (UNISC), Santa Cruz do Sul, Brazil.
V G
VG
Gava
Oncological Center of Ana Nery Hospital and Saint Gallen Institute of Oncology, Santa Cruz do Sul, Brazil.
M A
MA
Magalhaes
University of Santa Cruz do Sul (UNISC), Santa Cruz do Sul, Brazil; Oncological Center of Ana Nery Hospital and Saint Gallen Institute of Oncology, Santa Cruz do Sul, Brazil.
M L
ML
Dotto
D000230:Adenocarcinoma / Q000556:secondary / Q000601:surgery*; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006498:Hepatectomy / Q000379:methods*; D006503:Hepatic Veins / Q000601:surgery*; D006801:Humans; D006984:Hypertrophy / Q000000981:diagnostic imaging; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging / Q000601:surgery*; D008113:Liver Neoplasms / Q000556:secondary / Q000601:surgery*; D008115:Liver Regeneration; D008875:Middle Aged; D011169:Portal Vein / Q000601:surgery; D014057:Tomography, X-Ray Computed
Hepatectomy; Liver hypertrophy; Outflow modulation