Segment 5 parenchymal sparing in extended left hepatectomy with respect to venous outflow-is it a feasible procedure?

Segment 5 (S5) sparing liver resection for cases that require an anatomic left trisectionectomy has not been reported yet. The authors intended to verify the outcome of S5-sparing extended left hepatectomy (ELH) in respect to venous outflow.

All adult patients who underwent S5-sparing ELH between 2012 and 2017 in authors' institute have been enrolled in this study. S5-sparring ELH was defined as resection of S2, S3, S4, and S8 with or without S1. The surgery planning was based on the images from two-dimensional triphasic computed tomography and/or magnetic resonance imaging. A three-dimensional image reconstruction and liver volumetric study were performed retrospectively.

Out of 177 cases of major hepatic resection, only seven non-hilar cholangiocarcinoma patients underwent ELH during the study period. S5-sparing ELH was performed to five patients, in whom no tumor involvement in S5. The venous outflow of S5 has been maintained intraoperative, and S5 congestion has not been observed in all patients. Tailored management of the S5 venous outflow ensured an increase in functional remnant liver volume by 52.8% (range, 25.6 to 66.9%) by sparing of S5. A negative resection margin was achieved in all patients. One patient had postoperative bile leak requiring reoperation. No posthepatectomy liver failure (PHLF) has been observed.

S5-sparing ELH is technically feasible. Under the tailored management of S5 venous outflow, the functional future liver remnant can be increased. Further studies with larger sample size are needed to evaluate which circumstances the liver segment 5 could be preserved without venous reconstruction during the left extended hepatectomy.