Introduction. Parenchyma sparing hepatectomy (PSH) assures adequate future
liver remnant (FLR) for deep located tumours, however, PSH requires complex
surgical procedures with a learning curve that has never been analysed.

Methods. Data from 126 consecutive patients treated with a PSH during the first 9
years of practice were registered in a prospective database. One patient with
preoperative total bilirubin >5 mg/dl was excluded. The initial period (4y) of low
(<14/y) and the later period (5y) of high (>14/y) case volume were compared.

Results. Low (n=24) and high (n=101) case volume groups were comparable
(P>0.05) for patient’s baseline characteristics, PSH requiring HV exposure/resection
(92% vs 78%), PSH with vascular reconstruction (25% vs 25%), extrahepatic surgical
procedures (25% vs 28%), median blood loss (150 vs 150 ml), blood transfusion
(37% vs 27%), overall (50% vs 38%) and severe (8% vs 8%) postoperative
complications and median length of stay (8.5 vs 9 days). Overall 90-day mortality
was 1.6%. In high volume case period there was an increasing attitude in
first/second order glissonian pedicles exposure (33% vs 68%; P=0.001) and the
mean biggest lesion size was greater (41+24 cm vs 55+37 cm, P=0.034).
Furthermore the operative time was shorter (714+316 min vs 595+242 min,
P=0.048) and the resected liver surface per minute was larger (0.93+0.35 cm2/min
vs 1.44+0.69 cm2/min, P=0.001).

Conclusions. The learning curve had significant impact on the operative time and
on the surface area resected per minute, in spite of an increased attitude in
first/second order glissonian pedicles exposure and increased mean biggest lesion
size.