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.

Conversion surgery for initially unresectable locally advanced biliary tract cancer: A multicenter collaborative study conducted in Japan and Korea.

BACKGROUND: Although surgical resection is the only curative treatment for biliary tract cancer, in some cases, the disease is diagnosed as unresectable at initial presentation. There are few reports of conversion surgery after the initial treatment for unresectable locally advanced biliary tract cancer. This study aimed to evaluate the efficacy and safety of conversion surgery in patients with initially unresectable locally advanced biliary tract cancer. METHODS: We retrospectively collected clinical data from groups of patients in multiple centers belonging to the Japanese Society of Hepato-Biliary-Pancreatic Surgery and Korean Association of Hepato-Biliary-Pancreatic Surgery. We analyzed two groups of prognostic factors (pretreatment and surgical factors) and their relation to the treatment outcomes. RESULTS: A total of 56 patients with initially unresectable locally advanced biliary tract cancer were enrolled in this study of which 55 (98.2%) patients received chemotherapy, and 16 (28.6%) patients received additional radiation therapy. The median time from the start of the initial treatment to resection was 6.4 months. Severe postoperative complications of Clavien-Dindo grade III or higher occurred in 34 patients (60.7%), and postoperative mortality occurred in five patients (8.9%). Postoperative histological results revealed CR in eight patients (14.3%). The median survival time from the start of the initial treatment in all 56 patients who underwent conversion surgery was 37.7 months, the 3-year survival rate was 53.9%, and the 5-year survival rate was 39.1%. CONCLUSIONS: Conversion surgery for initially unresectable locally advanced biliary tract cancer may lead to longer survival in selected patients. However, more precise preoperative safety evaluation and careful postoperative management are required.

Surgical outcome and risk scoring to predict survival after hepatic resection for hepatocellular carcinoma with portal vein tumor thrombosis.

Backgrounds/Aims: The hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is classified as the advanced stage (BCLC stage C) with extremely poor prognosis, and in current guidelines is recommended for systemic therapy. This study aimed to evaluate the surgical outcomes and long-term prognosis after hepatic resection (HR) for patients who have HCC combined with PVTT. Methods: We retrospectively analyzed 332 patients who underwent HR for HCC with PVTT at ten tertiary referral hospitals in South Korea. Results: The median overall and recurrence-free survival after HR were 32.4 and 8.6 months, while the 1-, 3-, and 5-year overall survival rates were 75%, 48%, and 39%, respectively. In multivariate analysis, tumor number, tumor size, AFP, PIVKA-II, neutrophil-to-lymphocyte ratio, and albumin-bilirubin (ALBI) grade were significant prognostic factors. The risk scoring was developed using these seven factors-tumor, inflammation and hepatic function (TIF), to predict patient prognosis. The prognosis of the patients was well stratified according to the scores (log-rank test, p < 0.001). Conclusions: HR for patients who have HCC combined with PVTT provided favorable survival outcomes. The risk scoring was useful in predicting prognosis, and determining the appropriate treatment strategy for those patients who have HCC with PVTT.

Efficacy and Safety of Surgical Resection in Elderly Patients with Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

Background/Aims: : With increased life expectancy, the management of elderly hepatocellular carcinoma (HCC) patients became a crucial issue, yet it is still challenging due to comorbidities and high surgical risks. While surgical resection is considered as primary treatment for eligible HCC patients, systematic evidence on its outcomes in elderly patients remains scarce. In this review, we aimed to analyze the efficacy and safety outcomes of surgical resection in elderly HCC patients. Methods: : The studies included in this meta-analysis were selected from Ovid-MEDLINE, Ovid-Embase, CENTRAL, KoreaMed, KMbase, and KISS databases following a predefined protocol. Efficacy outcomes included overall survival and disease-free survival, while the safety outcomes included postoperative mortality and complications. Results: : Patients in the elderly group (≥65 years) who underwent surgery exhibited non-inferior overall survival (hazard ratio [HR], 1.26; 95% confidence interval [CI], 0.92 to 1.74) and disease-free survival (HR, 1.03; 95% CI, 0.99 to 1.08) compared to the non-elderly group. Overall postoperative mortality exhibited no statistical difference (odds ratio [OR], 1.07; 95% CI, 0.87 to 1.31), but 30-day, 90-day, and in-hospital mortality were higher in the elderly group. The incidence of overall complications was higher in the elderly group (OR, 1.44; 95% CI, 1.22 to 1.69). Sensitivity analysis for the super elderly group (≥80 years) showed significantly higher in-hospital mortality compared to the non-super elderly group (OR, 2.51; 95% CI, 1.16 to 5.45). Conclusions: : The efficacy outcome of surgical resection in the elderly HCC patients was not worse than that in the non-elderly HCC patients, while in-hospital mortality and complications rates were higher. Therefore, surgical resection should be purposefully considered in the elderly population, with careful candidate selection.

Impact of neoadjuvant chemotherapy on short-term outcomes after simple and complex minimally invasive minor hepatectomy for colorectal liver metastases: A propensity-score matched and coarsened exact matched study.

BACKGROUND: In the last three decades, minimally invasive liver resection has been replacing conventional open approach in liver surgery. More recently, developments in neoadjuvant chemotherapy have led to increased multidisciplinary management of colorectal liver metastases with both medical and surgical treatment modalities. However, the impact of neoadjuvant chemotherapy on the surgical outcomes of minimally invasive liver resections remains poorly understood. METHODS: A multicenter, international, database of 4998 minimally invasive minor hepatectomy for colorectal liver metastases was used to compare surgical outcomes in patients who received neoadjuvant chemotherapy with surgery alone. To correct for baseline imbalance, propensity score matching, coarsened exact matching and inverse probability treatment weighting were performed. RESULTS: 2546 patients met the inclusion criteria. After propensity score matching there were 759 patients in both groups and 383 patients in both groups after coarsened exact matching. Baseline characteristics were equal after both matching strategies. Neoadjuvant chemotherapy was not associated with statistically significant worse surgical outcomes of minimally invasive minor hepatectomy. CONCLUSION: Neoadjuvant chemotherapy had no statistically significant impact on short-term surgical outcomes after simple and complex minimally invasive minor hepatectomy for colorectal liver metastases.

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.

Comparison of Surgical Resection and Radiofrequency Ablation in Elderly Patients with Hepatocellular Carcinoma.

BACKGROUND/AIMS: The aim of this study was to examine whether the efficacy of radiofrequency ablation (RFA) and surgical resection (SR) are comparable for hepatocellular carcinoma (HCC) less than 3 cm in elderly individuals aged 65 years or older. METHODS: We used the National Health Insurance Service claims data in Korea, which was linked with liver cancer stage data from the Central Cancer Registry of the National Cancer Center, as well as death data from the National Statistical Office. Out of the 9213 registrants, we focused on 141 patients who underwent SR and 225 patients who underwent RFA when they were 65 years or older. To ensure comparability, a 1:1 propensity score (PS) matching was conducted. RESULTS: The SR group had lower performance status and better liver function compared to the RFA group. Tumor diameter was larger in the SR group than in the RFA group (2.1 cm vs. 1.7 cm), and the proportion of stage II cases was higher (62.4% vs. 33.8%). After PS matching, the mortality rate in the RFA group did not significantly differ from the SR group (HR 1.33, 95% CI 0.86-2.06, P = 0.19). Also, liver related mortality was similar between the SR and RFA group after matching (log rank P = 0.13). However, recurrence free survival was significantly longer in the SR group than RFA group before and after matching (log rank P = 0.03). CONCLUSION: In patients aged 65 years or older with resectable HCC, RFA demonstrates a therapeutic effect comparable to SR.

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.

Radiofrequency Ablation versus Surgical Resection in Elderly Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

Although the disease burden of elderly cancer patients is rapidly increasing, reliable scientific information, value and preference information of domestic patients, and standardized guidelines for determining the treatment of elderly cancer patients are lacking. The aim of this study is to compare the therapeutic effects of radiofrequency ablation (RFA) and surgery in hepatocellular carcinoma (HCC) patients aged 65 years or older. For the meta-analysis, the databases including PubMed (MEDLINE), EMBASE, OVID Medline, and the Cochrane Library were systematically searched. After the abstract-based review by two investigators, selected manuscripts were read in detail. The surgery group showed higher overall survival (OS) (HR 1.44, 95% CI 1.22-1.70) and disease-free survival (DFS) (HR 1.40, 95% CI 1.00-1.97) than the RFA group. This was also shown in small HCC of less than 3 cm (OS, HR 1.42, 95% CI 1.00-2.03; DFS, HR 1.32, 95% CI 0.91-1.91). This might be related to the high local recurrence in the RFA group (OR 4.90, 95% 2.16-11.08). On the other hand, adverse events were significantly lower in the RFA group (OR 0.22, 95% CI 0.14-0.36), which led to a decrease in the duration of hospital stay (mean difference -14.88 days, 95% CI -22.44--7.32). In elderly HCC patients, survival in the surgery group was significantly higher than in the RFA group, but various complications tended to increase; so, appropriate patient selection is required.

Propensity Score-Matching Analysis Comparing Robotic Versus Laparoscopic Limited Liver Resections of the Posterosuperior Segments: An International Multicenter Study.

OBJECTIVE: The purpose of this study was to compare the outcomes of robotic limited liver resections (RLLR) versus laparoscopic limited liver resections (LLLR) of the posterosuperior segments. BACKGROUND: Both laparoscopic and robotic liver resections have been used for tumors in the posterosuperior liver segments. However, the comparative performance and safety of both approaches have not been well examined in the existing literature. METHODS: This is a post hoc analysis of a multicenter database of 5446 patients who underwent RLLR or LLLR of the posterosuperior segments (I, IVa, VII, and VIII) at 60 international centers between 2008 and 2021. Data on baseline demographics, center experience and volume, tumor features, and perioperative characteristics were collected and analyzed. Propensity score-matching (PSM) analysis (in both 1:1 and 1:2 ratios) was performed to minimize selection bias. RESULTS: A total of 3510 cases met the study criteria, of whom 3049 underwent LLLR (87%), and 461 underwent RLLR (13%). After PSM (1:1: and 1:2), RLLR was associated with a lower open conversion rate [10 of 449 (2.2%) vs 54 of 898 (6.0%); P =0.002], less blood loss [100 mL [IQR: 50-200) days vs 150 mL (IQR: 50-350); P <0.001] and a shorter operative time (188 min (IQR: 140-270) vs 222 min (IQR: 158-300); P <0.001]. These improved perioperative outcomes associated with RLLR were similarly seen in a subset analysis of patients with cirrhosis-lower open conversion rate [1 of 136 (0.7%) vs 17 of 272 (6.2%); P =0.009], less blood loss [100 mL (IQR: 48-200) vs 160 mL (IQR: 50-400); P <0.001], and shorter operative time [190 min (IQR: 141-258) vs 230 min (IQR: 160-312); P =0.003]. Postoperative outcomes in terms of readmission, morbidity and mortality were similar between RLLR and LLLR in both the overall PSM cohort and cirrhosis patient subset. CONCLUSIONS: RLLR for the posterosuperior segments was associated with superior perioperative outcomes in terms of decreased operative time, blood loss, and open conversion rate when compared with LLLR.

Robotic and laparoscopic right lobe living donation compared to the open approach: A multicenter study on 1194 donor hepatectomies.

Due to the success of minimally invasive liver surgery, laparoscopic and robotic minimally invasive donor hepatectomies (MIDH) are increasingly performed worldwide. We conducted a retrospective, multicentre, propensity score-matched analysis on right lobe MIDH by comparing the robotic, laparoscopic, and open approaches to assess the feasibility, safety, and early outcomes of MIDHs. From January 2016 until December 2020, 1194 donors underwent a right donor hepatectomy performed with a robotic (n = 92), laparoscopic (n = 306), and open approach (n = 796) at 6 high-volume centers. Donor and recipients were matched for different variables using propensity score matching (1:1:2). Donor outcomes were recorded, and postoperative pain was measured through a visual analog scale. Recipients' outcomes were also analyzed. Ninety-two donors undergoing robotic surgery were matched and compared to 92 and 184 donors undergoing laparoscopic and open surgery, respectively. Conversions to open surgery occurred during 1 (1.1%) robotic and 2 (2.2%) laparoscopic procedures. Robotic procedures had a longer operative time (493 ± 96 min) compared to laparoscopic and open procedures (347 ± 120 and 358 ± 95 min; p < 0.001) but were associated with reduced donor blood losses ( p < 0.001). No differences were observed in overall and major complications (≥ IIIa). Robotic hepatectomy donors had significantly less pain compared to the 2 other groups ( p < 0.001). Fifty recipients of robotic-procured grafts were matched to 50 and 100 recipients of laparoscopic and open surgery procured grafts, respectively. No differences were observed in terms of postoperative complications, and recipients' survival was similar ( p =0.455). In very few high-volume centers, robotic right lobe procurement has shown to be a safe procedure. Despite an increased operative and the first warm ischemia times, this approach is associated with reduced intraoperative blood losses and pain compared to the laparoscopic and open approaches. Further data are needed to confirm it as a valuable option for the laparoscopic approach in MIDH.

Impact of liver cirrhosis, severity of cirrhosis and portal hypertension on the difficulty of laparoscopic and robotic minor liver resections for primary liver malignancies in the anterolateral segments.

INTRODUCTION: We performed this study in order to investigate the impact of liver cirrhosis (LC) on the difficulty of minimally invasive liver resection (MILR), focusing on minor resections in anterolateral (AL) segments for primary liver malignancies. METHODS: This was an international multicenter retrospective study of 3675 patients who underwent MILR across 60 centers from 2004 to 2021. RESULTS: 1312 (35.7%) patients had no cirrhosis, 2118 (57.9%) had Child A cirrhosis and 245 (6.7%) had Child B cirrhosis. After propensity score matching (PSM), patients in Child A cirrhosis group had higher rates of open conversion (p = 0.024), blood loss >500 mls (p = 0.001), blood transfusion (p < 0.001), postoperative morbidity (p = 0.004), and in-hospital mortality (p = 0.041). After coarsened exact matching (CEM), Child A cirrhotic patients had higher open conversion rate (p = 0.05), greater median blood loss (p = 0.014) and increased postoperative morbidity (p = 0.001). Compared to Child A cirrhosis, Child B cirrhosis group had longer postoperative stay (p = 0.001) and greater major morbidity (p = 0.012) after PSM, and higher blood transfusion rates (p = 0.002), longer postoperative stay (p < 0.001), and greater major morbidity (p = 0.006) after CEM. After PSM, patients with portal hypertension experienced higher rates of blood loss >500 mls (p = 0.003) and intraoperative blood transfusion (p = 0.025). CONCLUSION: The presence and severity of LC affect and compound the difficulty of MILR for minor resections in the AL segments. These factors should be considered for inclusion into future difficulty scoring systems for MILR.

Impact of Liver Cirrhosis, Severity of Cirrhosis, and Portal Hypertension on the Difficulty and Outcomes of Laparoscopic and Robotic Major Liver Resections for Primary Liver Malignancies.

BACKGROUND: Minimally invasive liver resections (MILR) offer potential benefits such as reduced blood loss and morbidity compared with open liver resections. Several studies have suggested that the impact of cirrhosis differs according to the extent and complexity of resection. Our aim was to investigate the impact of cirrhosis on the difficulty and outcomes of MILR, focusing on major hepatectomies. METHODS: A total of 2534 patients undergoing minimally invasive major hepatectomies (MIMH) for primary malignancies across 58 centers worldwide were retrospectively reviewed. Propensity score (PSM) and coarsened exact matching (CEM) were used to compare patients with and without cirrhosis. RESULTS: A total of 1353 patients (53%) had no cirrhosis, 1065 (42%) had Child-Pugh A and 116 (4%) had Child-Pugh B cirrhosis. Matched comparison between non-cirrhotics vs Child-Pugh A cirrhosis demonstrated comparable blood loss. However, after PSM, postoperative morbidity and length of hospitalization was significantly greater in Child-Pugh A cirrhosis, but these were not statistically significant with CEM. Comparison between Child-Pugh A and Child-Pugh B cirrhosis demonstrated the latter had significantly higher transfusion rates and longer hospitalization after PSM, but not after CEM. Comparison of patients with cirrhosis of all grades with and without portal hypertension demonstrated no significant difference in all major perioperative outcomes after PSM and CEM. CONCLUSIONS: The presence and severity of cirrhosis affected the difficulty and impacted the outcomes of MIMH, resulting in higher blood transfusion rates, increased postoperative morbidity, and longer hospitalization in patients with more advanced cirrhosis. As such, future difficulty scoring systems for MIMH should incorporate liver cirrhosis and its severity as variables.

A nationwide study on the current treatment status and natural prognosis of hepatocellular carcinoma in elderly.

The aim of this study was to identify the treatment status and natural prognosis of hepatocellular carcinoma (HCC) patients aged 65 years or older in Korea. We analyzed 3,492 patients' data from the liver cancer stage of the Central Cancer Registry of National Cancer Center. The most common etiology of HCC was hepatitis B (32.7%), followed by hepatitis C. 2624 patients (69.2%) received first-line active treatment for HCC. The most frequently selected treatment was transarterial chemoembolization (TACE), followed by surgical resection and radiofrequency ablation (RFA). The proportion of patients receiving supportive care increased with age. Second-line treatment was performed in only 36.7% of cases, with all others choosing supportive care. Among the various treatments, liver transplantation was found to have the greatest effect in reducing the risk of death (HR [hazard ratio] 0.164, 95% CI [confidence interval] 0.061-0.444), followed by resection, RFA, radioembolization, and TACE. A similar pattern was observed when sub-analyzing the age group over 75 years old. The median survival for untreated HCC in Barcelona Clinic Liver Cancer stage 0/A/B/C/D was 3.7 years, 2.3 years, 7.9 months, 3.9 months, and 2.9 months, respectively. This study highlights the current status of elderly patients with HCC in Korea. While the proportion of patients receiving supportive care is high among the elderly, effective treatment can improve their survival rate.

International experts consensus guidelines on robotic liver resection in 2023.

The robotic liver resection (RLR) has been increasingly applied in recent years and its benefits shown in some aspects owing to the technical advancement of robotic surgical system, however, controversies still exist. Based on the foundation of the previous consensus statement, this new consensus document aimed to update clinical recommendations and provide guidance to improve the outcomes of RLR clinical practice. The guideline steering group and guideline expert group were formed by 29 international experts of liver surgery and evidence-based medicine (EBM). Relevant literature was reviewed and analyzed by the evidence evaluation group. According to the WHO Handbook for Guideline Development, the Guidance Principles of Development and Amendment of the Guidelines for Clinical Diagnosis and Treatment in China 2022, a total of 14 recommendations were generated. Among them were 8 recommendations formulated by the GRADE method, and the remaining 6 recommendations were formulated based on literature review and experts' opinion due to insufficient EBM results. This international experts consensus guideline offered guidance for the safe and effective clinical practice and the research direction of RLR in future.

Impact of liver cirrhosis and portal hypertension on minimally invasive limited liver resection for primary liver malignancies in the posterosuperior segments: An international multicenter study.

INTRODUCTION: To assess the impact of cirrhosis and portal hypertension (PHT) on technical difficulty and outcomes of minimally invasive liver resection (MILR) in the posterosuperior segments. METHODS: This is a post-hoc analysis of patients with primary malignancy who underwent laparoscopic and robotic wedge resection and segmentectomy in the posterosuperior segments between 2004 and 2019 in 60 centers. Surrogates of difficulty (i.e, open conversion rate, operation time, blood loss, blood transfusion, and use of the Pringle maneuver) and outcomes were compared before and after propensity-score matching (PSM) and coarsened exact matching (CEM). RESULTS: Of the 1954 patients studied, 1290 (66%) had cirrhosis. Among the cirrhotic patients, 310 (24%) had PHT. After PSM, patients with cirrhosis had higher intraoperative blood transfusion (14% vs. 9.3%; p = 0.027) and overall morbidity rates (20% vs. 14.5%; p = 0.023) than those without cirrhosis. After coarsened exact matching (CEM), patients with cirrhosis tended to have higher intraoperative blood transfusion rate (12.1% vs. 6.7%; p = 0.059) and have higher overall morbidity rate (22.8% vs. 12.5%; p = 0.007) than those without cirrhosis. After PSM, Pringle maneuver was more frequently applied in cirrhotic patients with PHT (62.2% vs. 52.4%; p = 0.045) than those without PHT. CONCLUSION: MILR in the posterosuperior segments in cirrhotic patients is associated with higher intraoperative blood transfusion and postoperative morbidity. This parameter should be utilized in the difficulty assessment of MILR.

Impact of Tumor Size on the Difficulty of Laparoscopic Major Hepatectomies: An International Multicenter Study.

INTRODUCTION: Although tumor size (TS) is known to affect surgical outcomes in laparoscopic liver resection (LLR), its impact on laparoscopic major hepatectomy (L-MH) is not well studied. The objectives of this study were to investigate the impact of TS on the perioperative outcomes of L-MH and to elucidate the optimal TS cutoff for stratifying the difficulty of L-MH. METHODS: This was a post-hoc analysis of 3008 patients who underwent L-MH at 48 international centers. A total 1396 patients met study criteria and were included. The impact of TS cutoffs was investigated by stratifying TS at each 10-mm interval. The optimal cutoffs were determined taking into consideration the number of endpoints which showed a statistically significant split around the cut-points of interest and the magnitude of relative risk after correction for multiple risk factors. RESULTS: We identified 2 optimal TS cutoffs, 50 mm and 100 mm, which segregated L-MH into 3 groups. An increasing TS across these 3 groups (≤ 50 mm, 51-100 mm, > 100 mm), was significantly associated with a higher open conversion rate (11.2%, 14.7%, 23.0%, P < 0.001), longer operating time (median, 340 min, 346 min, 365 min, P = 0.025), increased blood loss (median, 300 ml,  ml, 400 ml, P = 0.002) and higher rate of intraoperative blood transfusion (13.1%, 15.9%, 27.6%, P < 0.001). Postoperative outcomes such as overall morbidity, major morbidity, and length of stay were comparable across the three groups. CONCLUSION: Increasing TS was associated with poorer intraoperative but not postoperative outcomes after L-MH. We determined 2 TS cutoffs (50 mm and 10 mm) which could optimally stratify the surgical difficulty of L-MH.

Impact of body mass index on perioperative outcomes of laparoscopic major hepatectomies.

BACKGROUND: Data on the effect of body mass index on laparoscopic liver resections are conflicting. We performed this study to investigate the association between body mass index and postoperative outcomes after laparoscopic major hepatectomies. METHODS: This is a retrospective review of 4,348 laparoscopic major hepatectomies at 58 centers between 2005 and 2021, of which 3,383 met the study inclusion criteria. Concomitant major operations, vascular resections, and previous liver resections were excluded. Associations between body mass index and perioperative outcomes were analyzed using restricted cubic splines. Modeled effect sizes were visually rendered and summarized. RESULTS: A total of 1,810 patients (53.5%) had normal weight, whereas 1,057 (31.2%) were overweight and 392 (11.6%) were obese. One hundred and twenty-four patients (3.6%) were underweight. Most perioperative outcomes showed a linear worsening trend with increasing body mass index. There was a statistically significant increase in open conversion rate (16.3%, 10.8%, 9.2%, and 5.6%, P < .001), longer operation time (320 vs 305 vs 300 and 266 minutes, P < .001), increasing blood loss (300 vs 300 vs 295 vs 250 mL, P = .022), and higher postoperative morbidity (33.4% vs 26.3% vs 25.0% vs 25.0%, P = .009) in obese, overweight, normal weight, and underweight patients, respectively (P < .001). However, postoperative major morbidity demonstrated a "U"-shaped association with body mass index, whereby the highest major morbidity rates were observed in underweight and obese patients. CONCLUSION: Laparoscopic major hepatectomy was associated with poorer outcomes with increasing body mass index for most perioperative outcome measures.

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.