Factors Associated with and Impact of Open Conversion in Laparoscopic and Robotic Minor Liver Resections: An International Multicenter Study of 10,541 Patients.

INTRODUCTION: Despite the increasing widespread adoption and experience in minimally invasive liver resections (MILR), open conversion occurs not uncommonly even with minor resections and as been reported to be associated with inferior outcomes. We aimed to identify risk factors for and outcomes of open conversion in patients undergoing minor hepatectomies. We also studied the impact of approach (laparoscopic or robotic) on outcomes. METHODS: This is a post-hoc analysis of 20,019 patients who underwent RLR and LLR across 50 international centers between 2004-2020. Risk factors for and perioperative outcomes of open conversion were analysed. Multivariate and propensity score-matched analysis were performed to control for confounding factors. RESULTS: Finally, 10,541 patients undergoing either laparoscopic (LLR; 89.1%) or robotic (RLR; 10.9%) minor liver resections (wedge resections, segmentectomies) were included. Multivariate analysis identified LLR, earlier period of MILR, malignant pathology, cirrhosis, portal hypertension, previous abdominal surgery, larger tumor size, and posterosuperior location as significant independent predictors of open conversion. The most common reason for conversion was technical issues (44.7%), followed by bleeding (27.2%), and oncological reasons (22.3%). After propensity score matching (PSM) of baseline characteristics, patients requiring open conversion had poorer outcomes compared with successful MILR cases as evidenced by longer operative times, more blood loss, higher requirement for perioperative transfusion, longer duration of hospitalization and higher morbidity, reoperation, and 90-day mortality rates. CONCLUSIONS: Multiple risk factors were associated with conversion of MILR even for minor hepatectomies, and open conversion was associated with significantly poorer perioperative outcomes.

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.

HEPATOSPLENIC SCHISTOSOMIASIS-ASSOCIATED CHRONIC PORTAL VEIN THROMBOSIS: RISK FACTOR FOR HEPATOCELLULAR CARCINOMA?

BACKGROUND: Hepatosplenic schistosomiasis is an endemic disease prevalent in tropical countries and is associated with a high incidence of portal vein thrombosis. Inflammatory changes caused by both parasitic infection and portal thrombosis can lead to the development of chronic liver disease with potential carcinogenesis. AIMS: To assess the incidence of portal vein thrombosis and hepatocellular carcinoma in patients with schistosomiasis during long-term follow-up. METHODS: A retrospective study was conducted involving patients with schistosomiasis followed up at our institution between 1990 and 2021. RESULTS: A total of 126 patients with schistosomiasis were evaluated in the study. The mean follow-up time was 16 years (range 5-31). Of the total, 73 (57.9%) patients presented portal vein thrombosis during follow-up. Six (8.1%) of them were diagnosed with hepatocellular carcinoma, all with portal vein thrombosis diagnosed more than ten years before. CONCLUSIONS: The incidence of hepatocellular carcinoma in patients with schistosomiasis and chronic portal vein thrombosis highlights the importance of a systematic long-term follow-up in this group of patients.

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.

Treatment of hepatocellular carcinoma with macroscopic vascular invasion: A systematic review and network meta-analysis.

BACKGROUND: This study aimed to evaluate the outcomes of different treatments for patients with hepatocellular carcinoma (HCC) and macroscopic vascular invasion. METHODS: A systematic review and meta-analysis of comparative studies was performed to evaluate various treatment modalities for HCC with macroscopic vascular invasion, including liver resection (LR), liver transplantation (LT), transarterial chemoembolization (TACE), transarterial radioembolization (TARE), radiotherapy (RT), radiofrequency ablation (RFA), and antineoplastic systemic therapy (AnST). RESULTS: After applying the selection criteria, 31 studies were included. The surgical resection (SR) group (including LR and LT) had a similar mortality rate to the non-surgical resection (NS) group (RD = -0.01; 95% CI -0.05 to 0.03). The SR group had a higher rate of complications (RD = 0.06; 95% CI 0.00 to 0.12) but a higher 3-year overall survival (OS) rate than the NS group (RD = 0.12; 95% CI 0.05 to 0.20). The network analysis revealed that the overall survival was lower in the AnST group. LT and LR had similar survival benefits. The meta-regression suggested that SR has a greater impact on the survival of patients with impaired liver function. DISCUSSION: Most likely, LT has a significant impact on long-term survival and consequently would be a better option for HCC with macroscopic vascular invasion in patients with impaired liver function. LT and LR offer a higher chance of long-term survival than NS alternatives, although LR and LR are associated with a higher risk of procedure-related complications.

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.

Impact of liver cirrhosis, the severity of cirrhosis, and portal hypertension on the outcomes of minimally invasive left lateral sectionectomies for primary liver malignancies.

BACKGROUND: The impact of cirrhosis and portal hypertension on perioperative outcomes of minimally invasive left lateral sectionectomies remains unclear. We aimed to compare the perioperative outcomes between patients with preserved and compromised liver function (noncirrhotics versus Child-Pugh A) when undergoing minimally invasive left lateral sectionectomies. In addition, we aimed to determine if the extent of cirrhosis (Child-Pugh A versus B) and the presence of portal hypertension had a significant impact on perioperative outcomes. METHODS: This was an international multicenter retrospective analysis of 1,526 patients who underwent minimally invasive left lateral sectionectomies for primary liver malignancies at 60 centers worldwide between 2004 and 2021. In the study, 1,370 patients met the inclusion criteria and formed the final study group. Baseline clinicopathological characteristics and perioperative outcomes of these patients were compared. To minimize confounding factors, 1:1 propensity score matching and coarsened exact matching were performed. RESULTS: The study group comprised 559, 753, and 58 patients who did not have cirrhosis, Child-Pugh A, and Child-Pugh B cirrhosis, respectively. Six-hundred and thirty patients with cirrhosis had portal hypertension, and 170 did not. After propensity score matching and coarsened exact matching, Child-Pugh A patients with cirrhosis undergoing minimally invasive left lateral sectionectomies had longer operative time, higher intraoperative blood loss, higher transfusion rate, and longer hospital stay than patients without cirrhosis. The extent of cirrhosis did not significantly impact perioperative outcomes except for a longer duration of hospital stay. CONCLUSION: Liver cirrhosis adversely affected the intraoperative technical difficulty and perioperative outcomes of minimally invasive left lateral sectionectomies.

Risk Factors and Outcomes of Open Conversion During Minimally Invasive Major Hepatectomies: An International Multicenter Study on 3880 Procedures Comparing the Laparoscopic and Robotic Approaches.

INTRODUCTION: Despite the advances in minimally invasive (MI) liver surgery, most major hepatectomies (MHs) continue to be performed by open surgery. This study aimed to evaluate the risk factors and outcomes of open conversion during MI MH, including the impact of the type of approach (laparoscopic vs. robotic) on the occurrence and outcomes of conversions. METHODS: Data on 3880 MI conventional and technical (right anterior and posterior sectionectomies) MHs were retrospectively collected. Risk factors and perioperative outcomes of open conversion were analyzed. Multivariate analysis, propensity score matching, and inverse probability treatment weighting analysis were performed to control for confounding factors. RESULTS: Overall, 3211 laparoscopic MHs (LMHs) and 669 robotic MHs (RMHs) were included, of which 399 (10.28%) had an open conversion. Multivariate analyses demonstrated that male sex, laparoscopic approach, cirrhosis, previous abdominal surgery, concomitant other surgery, American Society of Anesthesiologists (ASA) score 3/4, larger tumor size, conventional MH, and Institut Mutualiste Montsouris classification III procedures were associated with an increased risk of conversion. After matching, patients requiring open conversion had poorer outcomes compared with non-converted cases, as evidenced by the increased operation time, blood transfusion rate, blood loss, hospital stay, postoperative morbidity/major morbidity and 30/90-day mortality. Although RMH showed a decreased risk of conversion compared with LMH, converted RMH showed increased blood loss, blood transfusion rate, postoperative major morbidity and 30/90-day mortality compared with converted LMH. CONCLUSIONS: Multiple risk factors are associated with conversion. Converted cases, especially those due to intraoperative bleeding, have unfavorable outcomes. Robotic assistance seemed to increase the feasibility of the MI approach, but converted robotic procedures showed inferior outcomes compared with converted laparoscopic procedures.

Propensity-score Matched and Coarsened-exact Matched Analysis Comparing Robotic and Laparoscopic Major Hepatectomies: An International Multicenter Study of 4822 Cases.

OBJECTIVE: To compare the outcomes between robotic major hepatectomy (R-MH) and laparoscopic major hepatectomy (L-MH). BACKGROUND: Robotic techniques may overcome the limitations of laparoscopic liver resection. However, it is unknown whether R-MH is superior to L-MH. METHODS: This is a post hoc analysis of a multicenter database of patients undergoing R-MH or L-MH at 59 international centers from 2008 to 2021. Data on patient demographics, center experience volume, perioperative outcomes, and tumor characteristics were collected and analyzed. Both 1:1 propensity-score matched (PSM) and coarsened-exact matched (CEM) analyses were performed to minimize selection bias between both groups. RESULTS: A total of 4822 cases met the study criteria, of which 892 underwent R-MH and 3930 underwent L-MH. Both 1:1 PSM (841 R-MH vs. 841 L-MH) and CEM (237 R-MH vs. 356 L-MH) were performed. R-MH was associated with significantly less blood loss {PSM:200.0 [interquartile range (IQR):100.0, 450.0] vs 300.0 (IQR:150.0, 500.0) mL; P = 0.012; CEM:170.0 (IQR: 90.0, 400.0) vs 200.0 (IQR:100.0, 400.0) mL; P = 0.006}, lower rates of Pringle maneuver application (PSM: 47.1% vs 63.0%; P < 0.001; CEM: 54.0% vs 65.0%; P = 0.007) and open conversion (PSM: 5.1% vs 11.9%; P < 0.001; CEM: 5.5% vs 10.4%, P = 0.04) compared with L-MH. On subset analysis of 1273 patients with cirrhosis, R-MH was associated with a lower postoperative morbidity rate (PSM: 19.5% vs 29.9%; P = 0.02; CEM 10.4% vs 25.5%; P = 0.02) and shorter postoperative stay [PSM: 6.9 (IQR: 5.0, 9.0) days vs 8.0 (IQR: 6.0 11.3) days; P < 0.001; CEM 7.0 (IQR: 5.0, 9.0) days vs 7.0 (IQR: 6.0, 10.0) days; P = 0.047]. CONCLUSIONS: This international multicenter study demonstrated that R-MH was comparable to L-MH in safety and was associated with reduced blood loss, lower rates of Pringle maneuver application, and conversion to open surgery.

Impact of neoadjuvant chemotherapy on the difficulty and outcomes of laparoscopic and robotic major liver resections for colorectal liver metastases: A propensity-score and coarsened exact-matched controlled study.

BACKGROUND: Minimal invasive liver resections are a safe alternative to open surgery. Different scoring systems considering different risks factors have been developed to predict the risks associated with these procedures, especially challenging major liver resections (MLR). However, the impact of neoadjuvant chemotherapy (NAT) on the difficulty of minimally invasive MLRs remains poorly investigated. METHODS: Patients who underwent laparoscopic and robotic MLRs for colorectal liver metastases (CRLM) performed across 57 centers between January 2005 to December 2021 were included in this analysis. Patients who did or did not receive NAT were matched based on 1:1 coarsened exact and 1:2 propensity-score matching. Pre- and post-matching comparisons were performed. RESULTS: In total, the data of 5189 patients were reviewed. Of these, 1411 procedures were performed for CRLM, and 1061 cases met the inclusion criteria. After excluding 27 cases with missing data on NAT, 1034 patients (NAT: n = 641; non-NAT: n = 393) were included. Before matching, baseline characteristics were vastly different. Before matching, the morbidity rate was significantly higher in the NAT-group (33.2% vs. 27.2%, p-value = 0.043). No significant differences were seen in perioperative outcomes after the coarsened exact matching. After the propensity-score matching, statistically significant higher blood loss (mean, 300 (SD 128-596) vs. 250 (SD 100-400) ml, p-value = 0.047) but shorter hospital stay (mean, 6 [4-8] vs. 6 [5-9] days, p-value = 0.043) were found in the NAT-group. CONCLUSION: The current study demonstrated that NAT had minimal impact on the difficulty and outcomes of minimally-invasive MLR for CRLM.

Current status and future perspectives of radiomics in hepatocellular carcinoma.

Given the frequent co-existence of an aggressive tumor and underlying chronic liver disease, the management of hepatocellular carcinoma (HCC) patients requires experienced multidisciplinary team discussion. Moreover, imaging plays a key role in the diagnosis, staging, restaging, and surveillance of HCC. Currently, imaging assessment of HCC entails the assessment of qualitative characteristics which are prone to inter-reader variability. Radiomics is an emerging field that extracts high-dimensional mineable quantitative features that cannot be assessed visually with the naked eye from medical imaging. The main potential applications of radiomic models in HCC are to predict histology, response to treatment, genetic signature, recurrence, and survival. Despite the encouraging results to date, there are challenges and limitations that need to be overcome before radiomics implementation in clinical practice. The purpose of this article is to review the main concepts and challenges pertaining to radiomics, and to review recent studies and potential applications of radiomics in HCC.

Multiple colorectal liver metastases resection can offer long-term survival: The concept of a chronic neoplastic disease.

BACKGROUND: Resection for colorectal liver metastases has evolved significantly and, currently, there are no limits to the number of resected nodules. This study aimed to evaluate the outcomes and prognostic factors after liver resection for patients with ≥4 colorectal liver metastases, emphasizing long-term survival. METHODS: The study population consisted of 137 patients with ≥4 colorectal liver metastases out of a total of 597 patients with colorectal liver metastases who underwent curative intent liver resection from January 2010 to July 2019 in a single hepatobiliary center. RESULTS: The probability of overall and disease-free survival at 1, 3, and 5 years was 90.8%, 64.5%, 40.6%, and 37.7%, 19.3%, 18.1%, respectively. In a multivariate analysis for overall survival, the size of the largest metastatic nodule was the only unfavorable factor (P = .001). For disease-free survival, complete pathological response was a favorable factor (P = .04), and the following were negative factors: number of nodules ≥7 (P = .034), radiofrequency ablation during surgery (P = .04), positive primary tumor lymph nodes (P = .034), R1 resection (P = .011), and preoperative carcinoembryonic antigen >20 ng/mL (P = .015). After the first and second years of follow-up, 59 patients (45.3%) and 45 patients (34.6%), respectively, were not receiving chemotherapy. After 5 years of follow-up, 21 (16.1%) multimetastatic patients were chemotherapy-free. CONCLUSION: A significant number of patients with multiple colorectal liver metastases will present long-term survival and should not be denied surgery. The long-term survival rates, even in the presence of recurrence, characterize a chronic neoplastic disease.

Hepatosplenic schistosomiasis-associated chronic portal vein thrombosis: risk factor for hepatocellular carcinoma? / Esquistossomose hepatosplênica associada à trombose crônica da veia porta: fator de risco para o carcinoma hepatocelular?

ABSTRACT BACKGROUND: Hepatosplenic schistosomiasis is an endemic disease prevalent in tropical countries and is associated with a high incidence of portal vein thrombosis. Inflammatory changes caused by both parasitic infection and portal thrombosis can lead to the development of chronic liver disease with potential carcinogenesis. AIMS: To assess the incidence of portal vein thrombosis and hepatocellular carcinoma in patients with schistosomiasis during long-term follow-up. METHODS: A retrospective study was conducted involving patients with schistosomiasis followed up at our institution between 1990 and 2021. RESULTS: A total of 126 patients with schistosomiasis were evaluated in the study. The mean follow-up time was 16 years (range 5-31). Of the total, 73 (57.9%) patients presented portal vein thrombosis during follow-up. Six (8.1%) of them were diagnosed with hepatocellular carcinoma, all with portal vein thrombosis diagnosed more than ten years before. CONCLUSIONS: The incidence of hepatocellular carcinoma in patients with schistosomiasis and chronic portal vein thrombosis highlights the importance of a systematic long-term follow-up in this group of patients.

RESUMO RACIONAL: A esquistossomose hepatoesplênica é uma doença endêmica prevalente em países tropicais e está associada a uma alta incidência de trombose da veia porta. Alterações inflamatórias causadas tanto pela infecção parasitária quanto pela trombose portal podem levar ao desenvolvimento de doença hepática crônica com potencial carcinogênico. OBJETIVOS: Avaliar a incidência de trombose da veia porta e carcinoma hepatocelular em pacientes com esquistossomose durante um seguimento de longo prazo. MÉTODOS: Foi realizado estudo retrospectivo envolvendo pacientes com esquistossomose acompanhados em nossa instituição entre 1990 e 2021. RESULTADOS: Um total de 126 pacientes com esquistossomose foram avaliados no estudo. O tempo médio de acompanhamento foi de 16 anos (variando de 5 a 31). Do total, 73 (57,9%) pacientes apresentaram trombose da veia porta durante o seguimento e seis (8,1%) deles foram diagnosticados com carcinoma hepatocelular, todos com trombose da veia porta diagnosticada há mais de 10 anos. CONCLUSÕES: A incidência de carcinoma hepatocelular em pacientes com esquistossomose e trombose da veia porta crônica destaca a importância de um acompanhamento sistemático de longo prazo nesse grupo de pacientes.

Preoperative inflammatory markers as prognostic predictors after hepatocellular carcinoma resection: data from a western referral center.

BACKGROUND: Recent studies from eastern centers have demonstrate an association between inflammatory response and long-term outcomes after hepatocellular carcinoma (HCC) resection. However, the prognostic impact of inflammatory markers in western patients, with distinct tumor and epidemiologic features, is still unknown. AIM: To evaluate the prognostic impact of preoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR), as well as their impact according to tumor size (< 5 cm, 5-10 cm, > 10 cm) in patients undergoing HCC resection with curative intent. METHODS: Optimal cut-off values for NLR, PLR, and MLR were determined by plotting the receiver operator curves. Overall survival (OS) and disease-free survival (DFS) curves were calculated using the Kaplan-Meier method and compared using the log-rank test. The Cox method was used to identify independent predictors of OS and DFS. RESULTS: In total, 161 consecutive adult patients were included. A high NLR (> 1.715) was associated with worse OS (P = 0.018). High NLR (> 2.475; P = 0.047) and PLR (> 100.25; P = 0.028) were predictors of short DFS. In HCC < 5 cm, MLR (> 1.715) was associated with worse OS (P = 0.047). In the multivariate analysis, high PLR was an independent predictor of worse DFS [hazard ratio (HR) 3.029; 95%CI 1.499-6.121; P = 0.002]. CONCLUSION: Inflammatory markers are useful tools to predict long-term outcomes after liver resection in western patients, high NLR was able to stratify subgroups of patients with short OS and DFS, an increased PLR was an independent predictor of short DFS, while high MLR was associated with short OS in patients with early HCC.

The impact of multivisceral liver resection on short- and long-term outcomes of patients with colorectal liver metastasis: A systematic review and meta-analysis.

The impact of Multivisceral Liver Resection (MLR) on the outcome of patients with Colorectal Liver Metastasis (CRLM) is unclear. The present systematic review aimed to compare patients with CRLM who underwent MLR versus standard hepatectomy regarding short- and long-term outcomes. MLR is a feasible procedure but has a higher risk of major complications. MLR did not negatively affect long-term survival, suggesting that an extended resection is an option for potentially curative treatment for selected patients with CRLM.

Two decades of liver resection with a multidisciplinary approach in a single institution: What has changed? Analysis of 1409 cases.

OBJECTIVES: To evaluate results of patients undergoing liver resection in a single center over the past two decades with a particular look at Colorectal Liver Metastasis (CRLM) and Hepatocellular Carcinoma (HCC). METHOD: Patients were divided into two eras, from 2000 to 2010 (Era 1) and 2011 to 2020 (Era 2). The most frequent diagnosis was CRLM and HCC, with 738 (52.4%) and 227 (16.1%) cases respectively. An evaluation of all liver resection cases and a subgroup analysis of both CRLM and HCC were performed. Preoperative and per operative variables and long-term outcomes were evaluated. RESULTS: 1409 liver resections were performed. In Era 2 the authors observed higher BMI, more: minimally invasive surgeries, Pringle maneuvers, and minor liver resections; and less transfusion, less ICU necessity, and shorter length of hospital stay. Severe complications were observed in 14.7% of patients, and 90-day mortality was 4.2%. Morbidity and mortality between eras were not different. From 738 CRLM resections, in Era 2 there were significantly more patients submitted to neoadjuvant chemotherapy, bilateral metastases, and smaller sizes with significantly less transfusion, the necessity of ICU, and shorter length of hospital stay. More pedicle clamping, minimally invasive surgeries, and minor resections were also observed. From 227 HCC resections, in Era 2 significantly more minimally invasive surgeries, fewer transfusions, less necessity of ICU, and shorter length of hospital stay were observed. OS was not different between eras for CRLM and HCC. CONCLUSIONS: Surgical resection in a multidisciplinary environment remains the cornerstone for the curative treatment of primary and metastatic liver tumors.

Utility of the Iwate difficulty scoring system for laparoscopic right posterior sectionectomy: do surgical outcomes differ for tumors in segments VI and VII?

INTRODUCTION: The Iwate Score (IS) have not been well-validated for specific procedures, especially for right posterior sectionectomy (RPS). In this study, the utility of the IS was determined for laparoscopic (L)RPS and the effect of tumor location on surgical outcomes was investigated. METHODS: Post-hoc analysis of 647 L-RPS performed in 40 international centers of which 596L-RPS cases met the inclusion criteria. Baseline characteristics and perioperative outcomes of patients stratified based on the Iwate score were compared to determine whether a correlation with surgical difficulty existed. A 1:1 Mahalanobis distance matching was utilized to investigate the effect of tumor location on L-RPS outcomes. RESULTS: The patients were stratified into 3 levels of difficulty (31 intermediate, 143 advanced, and 422 expert) based on the IS. When using a stepwise increase of the IS excluding the tumor location score, only Pringle's maneuver was more frequently used in the higher surgical difficulty level (35.5%, 54.6%, and 65.2%, intermediate, advanced, and expert levels, respectively, Z = 3.34, p = 0.001). Other perioperative results were not associated with a statistical gradation toward higher difficulty level. 80 of 85 patients with a segment VI lesion and 511 patients with a segment VII lesion were matched 1:1. There were no significant differences in the perioperative outcomes of the two groups including open conversion, operating time, blood loss, intraoperative blood transfusion, postoperative stay, major morbidity, and mortality. CONCLUSION: Among patients undergoing L-RPS, the IS did not significantly correlate with most outcome measures associated with intraoperative difficulty and postoperative outcomes. Similarly, tumor location had no effect on L-RPS outcomes.