Chip collection of hepatocellular carcinoma based on O2 heterogeneity from patient tissue.

Hepatocellular carcinoma frequently recurs after surgery, necessitating personalized clinical approaches based on tumor avatar models. However, location-dependent oxygen concentrations resulting from the dual hepatic vascular supply drive the inherent heterogeneity of the tumor microenvironment, which presents challenges in developing an avatar model. In this study, tissue samples from 12 patients with hepatocellular carcinoma are cultured directly on a chip and separated based on preference of oxygen concentration. Establishing a dual gradient system with drug perfusion perpendicular to the oxygen gradient enables the simultaneous separation of cells and evaluation of drug responsiveness. The results are further cross-validated by implanting the chips into mice at various oxygen levels using a patient-derived xenograft model. Hepatocellular carcinoma cells exposed to hypoxia exhibit invasive and recurrent characteristics that mirror clinical outcomes. This chip provides valuable insights into treatment prognosis by identifying the dominant hepatocellular carcinoma type in each patient, potentially guiding personalized therapeutic interventions.

Preoperative Prediction of Microvascular Invasion with Gadoxetic Acid-Enhanced Magnetic Resonance Imaging in Patients with Single Hepatocellular Carcinoma: The Implication of Surgical Decision on the Extent of Liver Resection.

Introduction: Microvascular invasion (MVI) is one of the most important prognostic factors for hepatocellular carcinoma (HCC) recurrence, but its application in preoperative clinical decisions is limited. This study aimed to identify preoperative predictive factors for MVI in HCC and further evaluate oncologic outcomes of different types and extents of hepatectomy according to stratified risk of MVI. Methods: Patients with surgically resected single HCC (≤5 cm) who underwent preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI) were included in a single-center retrospective study. Two radiologists reviewed the images with no clinical, pathological, or prognostic information. Significant predictive factors for MVI were identified using logistic regression analysis against pathologic MVI and used to stratify patients. In the subgroup analysis, long-term outcomes of the stratified patients were analyzed using the Kaplan-Meier method with log-rank test and compared between anatomical and nonanatomical or major and minor resection. Results: A total of 408 patients, 318 men and 90 women, with a mean age of 56.7 years were included. Elevated levels of tumor markers (alpha-fetoprotein [α-FP] ≥25 ng/mL and PIVKA-II ≥40 mAU/mL) and three MRI features (tumor size ≥3 cm, non-smooth tumor margin, and arterial peritumoral enhancement) were independent predictive factors for MVI. As the MVI risk increased from low (no predictive factor) and intermediate (1-2 factors) to high-risk (3-4 factors), recurrence-free and overall survival of each group significantly decreased (p = 0.001). In the high MVI risk group, 5-year cumulative recurrence rate was significantly lower in patients who underwent major compared to minor hepatectomy (26.6 vs. 59.8%, p = 0.027). Conclusion: Tumor markers and MRI features can predict the risk of MVI and prognosis after hepatectomy. Patients with high MVI risk had the worst prognosis among the three groups, and major hepatectomy improved long-term outcomes in these high-risk patients.

Surgical strategy for incidental intrahepatic cholangiocarcinoma in terms of lymph node dissection.

BACKGROUND: Although many guidelines recommend performing lymph node dissection (LND) during surgery for intrahepatic cholangiocarcinoma (ICC), there is no evidence for patients with incidentally detected ICC who did not undergo LND. This study aimed to identify the role of LND in patients with incidental ICC. METHODS: The data from 284 patients who had undergone radical surgery for ICC from 2000 to 2020 were retrospectively reviewed. The enrolled patients were divided into 3 groups according to their T stage (T1 vs T2 vs T3 + 4). Moreover, the patients of each T group were divided into 3 groups according to their nodal status (N0 vs N1 vs Nx) and their survival outcomes were compared. RESULTS: Survival outcomes of Nx group were statistically similar to that of N0 group in T1 stage (Nx vs N0: disease-free survival [DFS] [months], 129.0 [75.6-182.4] vs 125.0 [65.7-184.3], P = .948; overall survival [OS] [months], 175.0 [153.9-196.1] vs 173.0 [109.0-237.0], P = .443). In contrast, survival outcomes of Nx group in the other T stage (T2 and T3 + 4) were poorer than that of N0 group and were better than that of N1 group. In addition, in the Nx subgroup analysis according to T stage, T1 group showed significantly better survival outcomes than the other groups (T1 vs T2 vs T3 + 4: DFS [months], 129.0 [75.9-182.1] vs 16.0 [9.8-22.2] vs 13.0 [0.3-25.7], P < .001; OS [months], 175.0 [153.9-196.1] vs 53.0 [30.8-75.2] vs 37.0 [17.6-56.4], P < .001). CONCLUSION: Patients with ICC incidentally diagnosed as having T2 or above T stage may consider additional LND.

Additional nodules detected using EOB-MRI in patients with resectable single hepatocellular carcinoma: an implication for active treatment strategy.

BACKGROUND/AIM: Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOBMRI) further enhances the identification of additional hepatic nodules compared with computed tomography (CT) alone; however, the optimal treatment for such additional nodules remains unclear. We investigated the long-term oncological effect of aggressive treatment strategies for additional lesions identified using EOB-MRI in patients with hepatocellular carcinoma (HCC). METHODS: Data from 522 patients diagnosed with solitary HCC using CT between January 2008 and December 2012 were retrospectively reviewed. Propensity score-matched (PSM) analysis was used to compare the oncologic outcomes between patients with solitary HCC and those with additional nodules on EOB-MRI after aggressive treatment (resection or radiofrequency ablation [RFA]). RESULTS: Among the 383 patients included, 59 had additional nodules identified using EOB-MRI. Compared with patients with solitary HCC, those with additional nodules on EOB-MRI had elevated total bilirubin, aspartate transaminase, and alanine transaminase; had a lower platelet count, higher MELD score, and highly associated with liver cirrhosis (P<0.05). Regarding long-term outcomes, 59 patients with solitary HCC and those with additional nodules after PSM were compared. Disease-free survival (DFS) and overall survival (OS) were comparable between the two groups (DFS, 60.4 vs. 44.3 months, P=0.071; OS, 82.8 vs. 84.8 months, P=0.986). CONCLUSION: The aggressive treatment approach, either resection or RFA, for patients with additional nodules identified on EOBMRI was associated with long-term survival comparable with that for solitary HCC. However, further studies are required to confirm these findings.

Prognostic impact of R1 resection margin in synchronous and simultaneous colorectal liver metastasis resection: a retrospective cohort study.

BACKGROUND: A margin ≥ 1 mm is considered a standard resection margin for colorectal liver metastasis (CRLM). However, microscopic incomplete resection (R1) is not rare since aggressive surgical resection has been attempted in multiple and bilobar CRLM. This study aimed to investigate the prognostic impact of resection margins and perioperative chemotherapy in patients with CRLM. METHODS: A total of 368 of 371 patients who underwent simultaneous colorectal and liver resection for synchronous CRLM between 2006 and June 2017, excluding three R2 resections, were included in this study. R1 resection was defined as either abutting tumor on the resection line or involved margin in the pathological report. The patients were divided into R0 (n = 304) and R1 (n = 64) groups. The clinicopathological characteristics, overall survival, and intrahepatic recurrence-free survival were compared between the two groups using propensity score matching. RESULTS: The R1 group had more patients with ≥ 4 liver lesions (27.3 vs. 50.0%, P < 0.001), higher mean tumor burden score (4.4 vs. 5.8%, P = 0.003), and more bilobar disease (38.8 vs. 67.2%, P < 0.001) than the R0 group. Both R0 and R1 groups showed similar long-term outcomes in the total cohort (OS, P = 0.149; RFS, P = 0.414) and after matching (OS, P = 0.097, RFS: P = 0.924). However, the marginal recurrence rate was higher in the R1 group than in the R0 group (26.6 vs. 16.1%, P = 0.048). Furthermore, the resection margin did not have a significant impact on OS and RFS, regardless of preoperative chemotherapy. Poorly differentiated, N-positive stage colorectal cancer, liver lesion number ≥ 4, and size ≥ 5 cm were poor prognostic factors, and adjuvant chemotherapy had a positive impact on survival. CONCLUSIONS: The R1 group was associated with aggressive tumor characteristics; however, no effect on the OS and intrahepatic RFS with or without preoperative chemotherapy was observed in this study. Tumor biological characteristics, rather than resection margin status, determine long-term prognosis. Therefore, aggressive surgical resection should be considered in patients with CRLM expected to undergo R1 resection in this multidisciplinary approach era.

Left-sided Hepatectomy Leads to Less Postoperative Liver Failure and Comparable Overall Survival to Right-sided Hepatectomy in Type II or IV Perihilar Cholangiocarcinoma.

INTRODUCTION: Right-side hepatectomy (RH) is used in oncological resection for perihilar cholangiocarcinoma (PHC); however, the decision between performing left-side hepatectomy (LH) or RH is still controversial. We compared surgical and oncologic outcomes of LH and RH in PHC type II or IV where either hepatectomy was expected to have a negative margin. METHODS: From 2001 to 2020, 99 patients underwent major liver resection for type II or IV PHC. Patients with unilateral vascular invasion, unilateral tumor growth, and atrophy of unilateral liver were excluded. Preoperative characteristics, perioperative, and long-term outcomes were compared between the remaining RH and LH patients. RESULTS: After excluding 47 cases with side predominance, the RH group (n = 29) and LH group (n = 23) were compared. Clinical characteristics and disease severity did not differ between the groups. Portal vein embolization (RH: 48.3% vs. LH: 0.0%, p < 0.001) and days from diagnosis to operation (RH: 31.0 ± 16.2 vs. LH: 18.8 ± 13.4, p = 0.006) were significantly higher in the RH group. The RH group had statistically higher rate of postoperative hepatic failure (RH: 55.2% vs. LH: 21.7%, p = 0.015) and a higher mortality rate that was not significant (RH: 13.8% vs. LH: 0%, p = 0.120). The R0 resection rate (RH: 72.4% vs. LH: 78.3%, p = 0.629), median disease-free (p = 0.620), and overall (p = 0.487) survival did not differ between groups. R1 resection and lymph node metastasis were significant risk factors for disease-free survival in multivariate analysis. CONCLUSIONS: In type II or type IV PHC where either LH or RH was feasible, LH provided a shorter period of preoperative preparation, lower postoperative hepatic failure rate, similar R0 rate, and comparable long-term outcomes. LH should be considered a reasonable option in type II or IV PHC.

The prognostic value of the number of metastatic lymph nodes on the long-term survival of intrahepatic cholangiocarcinoma using the SEER database.

Background: In the 8th edition of the American Joint Committee on Cancer, the nodal staging of intrahepatic cholangiocarcinoma (ICC) is classified as N0 and N1 in accordance with lymph node (LN) metastases. Recently, several studies have reported that the number of metastatic LNs is associated with prognosis in patients with ICC. However, the majority of these studies were published in Eastern countries, and there are few available data for Western countries. This study aimed to investigate the association between metastatic LN number and prognosis in ICC patients using the Surveillance, Epidemiology, and End Results (SEER) database. Methods: Data from 658 ICC patients in the SEER database who underwent hepatectomy with LN dissection from 2000 to 2018 were retrospectively reviewed. Hazard ratios (HRs) according to increasing numbers of metastatic LN were calculated. The patients were then divided into three groups according to their metastatic LN numbers (N0: no metastatic LNs; N+ <4: 1-3 metastatic LNs; N+ ≥4: ≥4 metastatic LNs), and cause-specific survival (CSS) was compared. Results: Metastatic LN number was a prognostic factor of oncologic survival [CSS: HR =1.300; 95% confidence interval (CI): 1.225-1.379; P<0.001]. In survival analysis, an increasing number of metastatic LNs was significantly correlated with poorer oncologic outcomes [CSS: N0 vs. N+ <4 vs. N+ ≥4: 40.856 (95% CI: 38.806-42.919) vs. 22.000 (95% CI: 18.283-25.717) vs. 15.000 (95% CI: 11.520-18.480) months, P<0.001]. In post hoc analysis, a significant difference was found between adjacent groups (N0 vs. N+ <4, P<0.001; N+ <4 vs. N+ ≥4, P=0.004). Conclusions: Patients with ICC in the SEER database were reaffirmed to have worse prognosis with an increasing number of metastatic LNs.

Comparison of surgical outcomes and learning curve for robotic versus laparoscopic living donor hepatectomy: A retrospective cohort study.

BACKGROUND: Both laparoscopic living donor right hemihepatectomy (LLDRH) and robotic living donor right hemihepatectomy (RLDRH) have been developed for minimally invasive donor hepatectomy (MIDH), although comparative analysis between the two surgical modalities is lacking. This study aims to compare surgical outcomes of LLDRH and RLDRH at a single institution. MATERIALS AND METHODS: From March 2016 to March 2022, 171 patients who underwent MILH of right liver were enrolled and divided into RLDRH and LLDRH. Two surgeons with experience in both techniques performed all procedures. Clinical characteristics, perioperative outcomes of donor and recipient, and donor anatomic variations were compared between both groups, and learning curves were estimated. Subgroup analysis was also performed, including only donors recruited after 2019, when LLDRH was initiated at our institution. RESULTS: RLDRH and LLDRH were performed for 102 and 69 patients, respectively. Operative time was significantly longer for RLDRH than LLDRH (464 vs. 407 min, P < 0.001), although estimated blood loss was lower in RLDRH (104 vs. 238 mL, P = 0.002). Incidence of major complications was similar in both groups. After 2019, significantly more RLDRH vs. LLDRH patients had variation in the hepatic artery (14.3% vs. 2.9%, P = 0.020) and portal vein (16.1% vs. 4.3%, P = 0.027). Learning curve for RLDRH was stabilized after approximately the 16th case, whereas that of LLDRH stabilized immediately. CONCLUSION: RLDRH resulted in less intraoperative bleeding and comparable postoperative outcomes than LLDRH. Moreover, since 2019, RLDRH has been employed more frequently for donors with hilar structure anatomic variations. Based on our single-center experience, we propose that standardized procedures for RLDRH might help set up pure minimally invasive procedures for donor hepatectomy and facilitate safe implementation of laparoscopic approaches.

Can the presence of KRAS mutations guide the type of liver resection during simultaneous resection of colorectal liver metastasis?

Backgrounds/Aims: It is generally accepted that non-anatomical resection (NAR) in colorectal liver metastasis (CRLM) has comparable safety and efficacy compared to anatomical resection (AR); however, there are reports that AR may have better outcomes in KRAS mutated CRLM. This study aimed to determine the effects of KRAS mutations and surgical techniques on survival outcomes in CRLM patients. Methods: Two hundred fifty patients who underwent hepatic resection of CRLM with known KRAS mutational status between 2007 and 2018 were analyzed. A total of 94 KRAS mutated CRLM and 156 KRAS wild-type CRLM were subdivided by surgical approach and compared for short- and long-term outcomes. Results: In both KRAS wild-type and mutated type, there was no difference in estimated blood loss, postoperative complications, and 30-day mortality. There was no difference in disease-free survival (DFS) between AR and NAR in both groups (p = 0.326, p = 0.954, respectively). Finally, there was no difference in intrahepatic DFS between AR and NAR groups in both the KRAS groups (p = 0.165, p = 0.516, respectively). Conclusions: The presence of KRAS mutation may not be a significant factor when deciding the approach in simultaneous resection of CRLM.

Prognostic impact of the metastatic lymph node number in intrahepatic cholangiocarcinoma.

BACKGROUND: Lymph node metastasis in intrahepatic cholangiocarcinoma is a poor prognostic factor after radical surgery. However, unlike other biliary tract malignancies, the nodal stage of intrahepatic cholangiocarcinoma only reflects the presence of metastatic lymph nodes, not the number of metastatic lymph nodes. This study aimed to identify the prognostic impact of the metastatic lymph node number in intrahepatic cholangiocarcinoma. METHODS: The data from 87 patients with intrahepatic cholangiocarcinoma who had undergone hepatectomy with 5 or more harvested lymph nodes and covering stations 12 and 8 based on the previous criteria from January 2006 to December 2019 were retrospectively reviewed. The hazard ratio according to the increasing metastatic lymph node number was calculated with other known prognostic factors for intrahepatic cholangiocarcinoma. The patients were then divided into 3 groups according to the metastatic lymph node number (N0 [n = 45]: no metastatic lymph nodes; N+ <4 [n = 32]: 1 to 3 metastatic lymph nodes; N+ ≥4 [n = 10]: ≥4 metastatic lymph nodes). Disease-free survival and overall survival were also analyzed. RESULTS: The metastatic lymph node number was a prognostic factor of oncologic survival (disease-free survival: hazard ratio = 1.18 [1.05-1.32], P = .005; overall survival: hazard ratio = 1.21 [1.06-1.37], P = .004). Survival analysis revealed significantly poorer outcomes with an increasing metastatic lymph node number (disease-free survival: N0 vs N+ <4 vs N+ ≥4: 36.0 [0.0-76.0] vs 8.0 [0.0-16.9] vs 2.0 [0.0-5.1] months, P < .001; overall survival: N0 vs N+ <4 vs N+ ≥4: 69.0 [24.5-113.5] vs 28.0 [18.9-37.1] vs 11.0 [6.4-15.6] months, P < .001). In post hoc analysis, a significant difference was found between adjacent groups (disease-free survival and overall survival: N+ <4 vs N+ ≥4, P = .001). CONCLUSION: With proper lymph node dissection, the number of metastatic lymph nodes is a prognostic factor of intrahepatic cholangiocarcinoma.

Outcomes of Robotic Living Donor Right Hepatectomy From 52 Consecutive Cases: Comparison With Open and Laparoscopy-assisted Donor Hepatectomy.

OBJECTIVE: To investigate the feasibility and safety of RLDRH. SUMMARY OF BACKGROUND DATA: Data for minimally invasive living-donor right hepatectomy, especially RLDRH, from a relatively large donor cohort that have not been reported yet. METHODS: From March 2016 to March 2019, 52 liver donors underwent RLDRH. The clinical and perioperative outcomes of RLDRH were compared with those of CODRH (n = 62) and LADRH (n = 118). Donor satisfaction with cosmetic results was compared between RLDRH and LADRH using a body image questionnaire. RESULTS: Although RLDRH was associated with longer operative time (minutes) (RLDRH, 493.6; CODRH, 404.4; LADRH, 355.9; P < 0.001), mean estimated blood loss (mL) was significantly lower (RLDRH, 109.8; CODRH, 287.1; LADRH, 265.5; P = 0.001). Postoperative complication rates were similar among the 3 groups (RLDRH, 23.1%; CODRH, 35.5%; LADRH, 28.0%; P = 0.420). Regarding donor satisfaction, body image and cosmetic appearance scores were significantly higher in RLDRH than in LADRH. After propensity score matching, RLDRH showed less estimated blood loss compared to those of CODRH (RLDRH, 114.7 mL; CODRH, 318.4 mL; P < 0.001), but complication rates were similar among the three groups (P = 0.748). CONCLUSIONS: RLDRH resulted in less blood loss compared with that of CODRH and similar postoperative complication rates to CODRH and LADRH. RLDRH provided better body image and cosmetic results compared with those of LADRH. RLDRH is feasible and safe when performed by surgeons experienced with both robotic and open hepatectomy.

Circulating Cancer Stem Cells Expressing EpCAM/CD90 in Hepatocellular Carcinoma: A Pilot Study for Predicting Tumor Recurrence after Living Donor Liver Transplantation.

Background/Aims: Circulating tumor cells (CTCs) with cancer stemness have been demonstrated to be a direct cause of tumor recurrence, and only few studies have reported the role of CTCs in liver transplantation (LT) for hepatocellular carcinoma (HCC). Methods: Epithelial cell adhesion molecule+ (EpCAM+), cluster of differentiation 90+ (CD90+) and EpCAM+/CD90+ CTCs were sorted via fluorescence-activated cell sorting, and transcripts level of EpCAM, K19 and CD90 in the peripheral blood were analyzed via real-time polymerase chain reaction preoperatively and on postoperative days 1 and 7 in 25 patients who underwent living donor liver transplantation (LDLT) for HCC. EpCAM protein was assessed in HCC tissue using immunohistochemical staining. The median follow-up duration was 40 months. Results: HCC after LDLT recurred in four out of 25 patients. Detection of EpCAM+ or CD90+ CTCs correlated well with their messenger RNA levels (p<0.05). EpCAM+ CTCs were readily detected in HCC tissue expressing EpCAM protein. The detection of EpCAM+ CTCs or EpCAM+/CD90+ CTCs before surgery and on postoperative day 1 was significantly associated with HCC recurrence after LT (all p<0.05). Pretransplant serum PIVKA-II >100 mAU/mL and postoperative day 1 EpCAM+/CD90+ CTCs were independent risk factors for HCC recurrence (hazard ratio, 14.64; 95% confidence interval, 1.08 to 198.20; p=0.043 and hazard ratio, 26.88; 95% confidence interval, 1.86 to 387.51; p=0.016, respectively). Conclusions: EpCAM+/CD90+ CTCs can be used preoperatively and 1 day after LDLT as key biological markers in LT candidate selection and post-LDLT management.

Extent of Lymph Node Dissection for Accurate Staging in Intrahepatic Cholangiocarcinoma.

BACKGROUND: Although lymph node metastasis is a known factor predictive of a poor prognosis after radical surgery for intrahepatic cholangiocarcinoma (ICC), few studies have investigated lymph node dissection (LND) areas for accurate staging. The aim of this study was to identify the optimal LND level for ICC considering lymphatic flow. METHODS: Clinical characteristics and pathologic nodal status (presence of metastasis) for 163 patients were reviewed according to tumor location. In the node-positive (N1) group, the distribution of metastatic nodes was described. The coverage of metastatic nodes according to dissection level was assessed, and the minimum dissection level for accurate ICC staging was estimated accordingly. For validation, the node-negative (N0) group was divided into two subgroups according to the estimated dissection level, and survival outcomes were compared. RESULTS: In the N1 group, expanding dissection to stations no. 12 and 8 covered 82.0% (n = 50) of metastatic cases regardless of tumor location. In survival analysis of N0 group, patients who underwent LND covering stations no. 8+12 showed better disease-free survival (DFS) and overall survival (OS), although the differences were not statistically significant (DFS: covering no. 12+8 vs. not covering no. 12+8, 109.0 months [24.2-193.8] vs. 33.0 months [10.3-55.7], p = 0.078; OS: covering no. 12+8 vs. not covering no. 12+8, 180.0 months [21.6-338.4] vs. 73.0 months [42.8-103.2], p = 0.080). CONCLUSION: LND including at least stations no. 12 (hepatoduodenal ligament) and 8 (common hepatic artery), regardless of tumor location, is recommended for accurate staging in ICC patients.

Impact of everolimus on survival after liver transplantation for hepatocellular carcinoma.

BACKGROUND/AIMS: This study aimed to investigate whether everolimus (EVR) affects long-term survival after liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). METHODS: The data from 303 consecutive patients with HCC who had undergone LT from January 2012 to July 2018 were retrospectively reviewed. The patients were divided into two groups: 1) patients treated with EVR in combination with calcineurin inhibitors (CNIs) (EVR group; n=114) and 2) patients treated with CNI-based therapy without EVR (non-EVR group; n=189). Time to recurrence (TTR) and overall survival (OS) after propensity score (PS) matching were compared between the groups, and prognostic factors for TTR and OS were evaluated. RESULTS: The EVR group exhibited more aggressive tumor biology than the non-EVR group, such as a higher number of tumors (P=0.003), a higher prevalence of microscopic vascular invasion (P=0.017) and exceeding Milan criteria (P=0.029). Compared with the PS-matched non-EVR group, the PS-matched EVR group had significantly better TTR (P<0.001) and OS (P<0.001). In multivariable analysis, EVR was identified as an independent prognostic factor for TTR (hazard ratio [HR], 0.248; P=0.001) and OS (HR, 0.145; P<0.001). CONCLUSION: Combined with CNIs, EVR has the potential to prolong long-term survival in patients undergoing LT for HCC. These findings warrant further investigation in a well-designed prospective study.

Liver Imaging Reporting and Data System Category on Magnetic Resonance Imaging Predicts Recurrence of Hepatocellular Carcinoma After Liver Transplantation Within the Milan Criteria: A Multicenter Study.

BACKGROUND: This study was designed to investigate the association between Liver Imaging Reporting and Data System (LI-RADS) category and recurrence of hepatocellular carcinoma (HCC) after primary liver transplantation (LT) within the Milan criteria. METHODS: This multicenter, retrospective study included 140 recipients who underwent living donor LT (LDLT) for treatment-naïve HCC and pretransplant contrast-enhanced magnetic resonance imaging (MRI) between 2009 and 2013. LI-RADS categories were assigned using LI-RADS version 2018. Recurrence-free survival (RFS) and associated factors were evaluated using Cox proportional hazards regression analysis, Kaplan-Meier analysis, and log-rank test. Histological grading and microvascular invasion (MVI) were analyzed on the pathologic examinations of explanted livers. RESULTS: The overall 1-, 3-, 5-, and 7-year RFS rates were 95.6%, 92.6%, 90.2%, and 89.3%, respectively. In the multivariable analysis, independent predictors of recurrence included HCCs categorized as LR-M (hazard ratio [HR], 18.68; 95% confidence interval [CI], 5.79-60.23; P < 0.001) and the largest tumor size of ≥ 3 cm on MRI (HR, 4.18; 95% CI, 1.42-12.37; P = 0.010). The 5-year RFS rate was significantly lower in patients with HCCs categorized as LR-M than in those with HCCs categorized as LR-5 or 4 (LR-5/4) (36.9% vs. 95.8%, respectively; P < 0.001). HCCs categorized as LR-M exhibited significantly more MVI than HCCs categorized as LR-5/4 (57.1% vs. 17.5%, respectively; P = 0.002). CONCLUSIONS: Patients with HCCs categorized as LR-M using LI-RADS version 2018 may have a worse prognosis after primary LT within the Milan criteria than those with HCCs categorized as LR-5/4.

Robotic major liver resections: Surgical outcomes compared with open major liver resections.

BACKGROUNDS/AIMS: Laparoscopic major liver resections are still considered innovative procedures despite the recent development of laparoscopic liver surgery. Robotic surgery has been introduced as an innovative system for laparoscopic surgery. In this study, we investigated surgical outcomes after major liver resections using robotic systems. METHODS: From January 2009 to October 2018, 70 patients underwent robotic major liver resections, which included conventional major liver resections and right sectionectomy. The short-term and long-term outcomes were compared with 252 open major resections performed during the same period. RESULTS: Operative time was longer in the robotic group (472 min vs. 349 min, p<0.001). However, estimated blood loss was lower in the robotic group compared with the open resection group (269 ml vs. 548 ml, p=0.009). The overall postoperative complication rate of the robotic group was lower than that of the open resection group (31.4% vs. 58.3%, p<0.001), but the major complication rate was similar between the two groups. Hospital stay was shorter in the robotic group (9.5 days vs. 15.1 days, p=0.006). Among patients with HCC, cholangiocarcinoma, and colorectal liver metastasis, there was no difference in overall and disease-free survival between the two groups. After propensity score matching in 37 patients with HCC for each group, the robotic group still showed a shorter hospital stay and comparable long-term outcomes. CONCLUSIONS: Robotic major liver resections provided improved perioperative outcomes and comparable long-term oncologic outcome compared with open resections. Therefore, robotic surgery should be considered one of the options for minimally invasive major liver resections.

Surgical outcomes of perihilar cholangiocarcinoma based on the learning curve of a single surgeon at a tertiary academic hospital: A retrospective study.

BACKGROUNDS/AIMS: Although it is difficult to master the surgical learning curve for treatment of perihilar cholangiocarcinoma (HCCA), there have been no studies on surgical outcomes between a novice and an experienced surgeon. Thus, the current study attempted to evaluate surgical outcomes from a single surgeon based on learning curve for surgical treatment of HCCA. METHODS: From January 2008 to December 2016, a single surgeon performed surgical treatment for 108 patients with HCCA at Severance Hospital, Seoul, Korea. Among them, 101 patients with curative surgical resection were included in this study. The learning curve was assessed by a moving average graph and CUSUM method using operation time. Surgical outcomes between the early period group (EPG) and the late period group (LPG) were compared according to learning curve. RESULTS: Operation time (603.17±117.59 and 432.03±91.77 minutes; p<0.001), amount of bleeding during operation (1127.86±689.54 and 613.05±548.31 ml; p<0.001), and severe complication rates (47.6% and 27.1%, p=0.034) were significantly smaller in the LPG. There was no significant difference in R0 resection rate (85.7% and 76.3%; p=0.241) as well as long-term survival rate. CONCLUSIONS: In this study, operation time, amount of bleeding during operation, length of hospital stay, and severe complication rate were improved after stabilization of the learning curve. However, R0 resection rate and survival outcomes were not significantly influenced by the learning curve for surgical treatment of HCCA.