Discussion
The first feasibility study for LH in 2000 concluded that LH was
feasible and safe in patients with left- and right-sided peripheral
lesions who required limited resection in 2000[4]. Since then, a
variety of feasibility studies for LH have been published for the
different circumstances, such tumor size[5], previous abdominal
surgery[6], cirrhotic patients[7], and elderly patients[8],
revealing that LH does not compromise perioperative outcomes, short-term
outcomes, and long-term survival. During this period, the indications
for LH have evolved from the Louisville statement in 2008[20], which
indicated the specific indications of LH, to the Morioka consensus in
2014[21], which found no definite indications for LH. Accordingly,
our center started LH with smaller tumors and performed minor resections
before performing major resections during the development period. We
also followed the Louisville statement to resect the tumor located at
peripheral segments, which means segments 2 to 6, which indicates
favorable location.
Several retrospective studies have evaluated the feasibility and safety
of LH in patients with HCC[22-24]. In these studies, LH was
associated with significantly less postoperative ascites (0.0% vs. 17.2
%, p = 0.025), shorter hospital stay (7.69 ± 2.94 vs. 13.38 ± 7.37
days, p < 0.001) without compromised long-term survival (12-,
36-, and 60-month survival rates of 100%, 100%, and 92.2%,
respectively). The 12-, 36-, and 60-month disease-free survival rates
were 81.7%, 61.7% and 54.0%, respectively in the study by Kim et
al.[22]. There was also significantly shorter operative time (80 vs.
140 min, p = 0.02), shorter hospital stay (7 vs. 12 days, p <
0.0001), and lower morbidity rates (20% vs. 4 %, p = 0.01) without
compromised long-term survival rate (1-, 5-, and 10-year rates of 88%,
59%, and 12%, respectively) in a study by Memeo et al.[23]. A
study by Lee et al. revealed significantly shorter postoperative
hospital stay (8 vs. 10 days, p = 0.003) without compromised 12-, 36-,
and 60-month overall survival rates (96.6%, 92.8%, and 73.3%,
respectively) disease-free survival rates (84.4%, 64.0%, and 60.2%,
respectively)[24]. Regarding tumor location, most papers on the
feasibility of LH focused on those in unfavorable locations. When
comparing posterior superior versus anterolateral tumors, Kwon et al.
reported that tumors in unfavorable locations would have similar median
blood loss (500 vs. 400 mL, p = 0.214), rate of intraoperative
transfusion (39% vs. 19%, p = 0.061), median postoperative hospital
stay (10 vs. 8 days, p = 0.166), and complication rate (21% vs. 11%, p
= 0.148)[25]. The INSTALL-2 study reported that tumors located at S7
and S8 had a median operative time of 315 min, postoperative hospital
stay of 7 days, and a major complicated rate of 11.9%[26].
Nevertheless, the aforementioned studies were conducted by a
well-developed and well-experienced center. The studies focused on tumor
location only provided evidence that LH would be feasible in unfavorable
locations when done in a high-quality center. Unfortunately, there is no
adequate evidence for centers that are eager to start the development of
LH. The present study analyzed cases of favorably located HCC that
underwent LH during the development period. According to the indications
of LH in the Louisville statement, LH was started at the parts of the
tumor in the favorable location and those that were of a smaller size;
minor resection was done before performing the more difficult resection
during the development period at our institution. This can explain why
the ratio of major resection was significantly greater in the F-OH group
than in F-LH group. During the development period in our study, the
ratio of laparoscopic intervention gradually increased and eventually
became the major intervention in the series as the technique was
developed. During the development period, the short-term outcomes (e.g.,
intraoperative blood loss, major complication rate, postoperative
hospital stay, 90-day readmission rate, and 90-day mortality rate) were
not compromised under the laparoscopic approach. The long-term outcomes,
including the overall, and disease-free survival rates, were not
influenced by use of the laparoscopic method, either. This study
provided evidence that centers starting to develop LH, even those that
are not high-volume centers (less than 20-50 liver resections per year),
may be benefit from using this technique on favorably located tumors
without significantly affecting short- and long-term outcomes, even not
in the high-volume center[27].
Only a few studies have focused on the experience of developing LH using
cases of favorably located tumors. We were able to demonstrate the
feasibility and safety when the technique is being developed in a single
center. These findings can hopefully encourage institutions who want to
start developing this procedure. However, this study still has some
limitations that should be discussed. First, this was a retrospective,
and non-randomized study, which may have led to observation bias.
Second, there was no short-, or long-term data on the quality of life,
such as the presence of incisional abdominal wall hernia and pain scale
assessments. Third, the study had a relatively small sample size and was
conducted in a single center. After the technique becomes more mature,
we will gradually start to apply LH in more difficult cases, and the
results will be presented in the following studies.