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.