Evaluation of the American College of Surgeons risk calculator in hepatectomy for metastatic colorectal cancer in a Southeast Asian population.

PURPOSE: This study evaluated the accuracy of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) calculator in predicting outcomes after hepatectomy for colorectal cancer (CRC) liver metastasis in a Southeast Asian population. METHODS: Predicted and actual outcomes were compared for 166 patients undergoing hepatectomy for CRC liver metastasis identified between 2017 and 2022, using receiver operating characteristic curves with area under the curve (AUC) and Brier score. RESULTS: The ACS-NSQIP calculator accurately predicted most postoperative complications (AUC > 0.70), except for surgical site infection (AUC = 0.678, Brier score = 0.045). It also exhibited satisfactory performance for readmission (AUC = 0.818, Brier score = 0.011), reoperation (AUC = 0.945, Brier score = 0.002), and length of stay (LOS, AUC = 0.909). The predicted LOS was close to the actual LOS (5.9 vs. 5.0 days, P = 0.985). CONCLUSION: The ACS-NSQIP calculator demonstrated generally accurate predictions for 30-day postoperative outcomes after hepatectomy for CRC liver metastasis in our patient population.

Comparative cost-effectiveness of open, laparoscopic, and robotic liver resection: A systematic review and network meta-analysis.

BACKGROUND: This study evaluated the cost-effectiveness of open, laparoscopic, and robotic liver resection. METHODS: A comprehensive literature review and Bayesian network meta-analysis were conducted. Surface under cumulative ranking area values, mean difference, odds ratio, and 95% credible intervals were calculated for all outcomes. Cluster analysis was performed to determine the most cost-effective clustering approach. Costs-morbidity, costs-mortality, and costs-efficacy were the primary outcomes assessed, with postoperative overall morbidity, mortality, and length of stay associated with total costs for open, laparoscopic, and robotic liver resection. RESULTS: Laparoscopic liver resection incurred the lowest total costs (laparoscopic liver resection versus open liver resection: mean difference -2,529.84, 95% credible intervals -4,192.69 to -884.83; laparoscopic liver resection versus robotic liver resection: mean difference -3,363.37, 95% credible intervals -5,629.24 to -1,119.38). Open liver resection had the lowest procedural costs but incurred the highest hospitalization costs compared to laparoscopic liver resection and robotic liver resection. Conversely, robotic liver resection had the highest total and procedural costs but the lowest hospitalization costs. Robotic liver resection and laparoscopic liver resection had a significantly reduced length of stay than open liver resection and showed less postoperative morbidity. Laparoscopic liver resection resulted in the lowest readmission and liver-specific complication rates. Laparoscopic liver resection and robotic liver resection demonstrated advantages in costs-morbidity efficiency. While robotic liver resection offered notable benefits in mortality and length of stay, these were balanced against its highest total costs, presenting a nuanced trade-off in the costs-mortality and costs-efficacy analyses. CONCLUSION: Laparoscopic liver resection represents a more cost-effective option for hepatectomy with superior postoperative outcomes and shorter length of stay than open liver resection. Robotic liver resection, though costlier than laparoscopic liver resection, along with laparoscopic liver resection, consistently exceeds open liver resection in surgical performance.

Evaluating the surgical trainee ergonomic experience during minimally invasive abdominal surgery (ESTEEMA study).

Minimally invasive abdominal surgery (MAS) can exert a physical cost. Surgical trainees spend years assisting minimally-invasive surgeries, increasing the risk of workplace injury. This prospective questionnaire-based cohort study was conducted amongst general surgery residents in Singapore. Residents assisting major MAS surgery were invited to complete anonymous online survey forms after surgery. The Phase 1 survey assessed physical discomfort scores and risk factors. Intraoperative measures to improve ergonomics were administered and evaluated in Phase 2. During Phase 1 (October 2021 to April 2022), physical discomfort was reported in at least one body part in 82.6% (n = 38) of respondents. Over a third of respondents reported severe discomfort in at least one body part (n = 17, 37.0%). Extremes of height, training seniority, longer surgical duration and operative complexity were significant risk factors for greater physical discomfort. In Phase 2 (October 2022 to February 2023), the overall rate of physical symptoms and severe discomfort improved to 81.3% (n = 52) and 34.4% (n = 22) respectively. The ergonomic measure most found useful was having separate television monitors for the primary surgeon and assistants, followed by intraoperative feedback on television monitor angle or position. Close to 20% of survey respondents felt that surgeon education was likely to improve physical discomfort.

Evaluating the economic efficiency of open, laparoscopic, and robotic distal pancreatectomy: an updated systematic review and network meta-analysis.

BACKGROUND: This study compared the cost-effectiveness of open (ODP), laparoscopic (LDP), and robotic (RDP) distal pancreatectomy (DP). METHODS: Studies reporting the costs of DP were included in a literature search until August 2023. Bayesian network meta-analysis was conducted, and surface under cumulative ranking area (SUCRA) values, mean difference (MD), odds ratio (OR), and 95% credible intervals (CrIs) were calculated for outcomes of interest. Cluster analysis was performed to examine the similarity and classification of DP approaches into homogeneous clusters. A decision model-based cost-utility analysis was conducted for the cost-effectiveness analysis of DP strategies. RESULTS: Twenty-six studies with 29,164 patients were included in the analysis. Among the three groups, LDP had the lowest overall costs, while ODP had the highest overall costs (LDP vs. ODP: MD - 3521.36, 95% CrI - 6172.91 to - 1228.59). RDP had the highest procedural costs (ODP vs. RDP: MD - 4311.15, 95% CrI - 6005.40 to - 2599.16; LDP vs. RDP: MD - 3772.25, 95% CrI - 4989.50 to - 2535.16), but incurred the lowest hospitalization costs. Both LDP (MD - 3663.82, 95% CrI - 6906.52 to - 747.69) and RDP (MD - 6678.42, 95% CrI - 11,434.30 to - 2972.89) had significantly reduced hospitalization costs compared to ODP. LDP and RDP demonstrated a superior profile regarding costs-morbidity, costs-mortality, costs-efficacy, and costs-utility compared to ODP. Compared to ODP, LDP and RDP cost $3110 and $817 less per patient, resulting in 0.03 and 0.05 additional quality-adjusted life years (QALYs), respectively, with positive incremental net monetary benefit (NMB). RDP costs $2293 more than LDP with a negative incremental NMB but generates 0.02 additional QALYs with improved postoperative morbidity and spleen preservation. Probabilistic sensitivity analysis suggests that LDP and RDP are more cost-effective options compared to ODP at various willingness-to-pay thresholds. CONCLUSION: LDP and RDP are more cost-effective than ODP, with LDP exhibiting better cost savings and RDP demonstrating superior surgical outcomes and improved QALYs.

Factors affecting overall survival and disease-free survival after surgery for hepatocellular carcinoma: a nomogram-based prognostic model-a Western European multicenter study.

Few studies have assessed the clinical implications of the combination of different prognostic indicators for overall survival (OS) and disease-free survival (DFS) of resected hepatocellular carcinoma (HCC). This study aimed to evaluate the prognostic factors in HCC patients for OS and DFS outcomes and establish a nomogram-based prognostic model to predict the DFS of HCC. A multicenter, retrospective European study was conducted through the collection of data on 413 consecutive treated patients with a first diagnosis of HCC between January 2010 and December 2020. Univariate and multivariate Cox regression analyses were performed to identify all independent risk factors for OS and DFS outcomes. A nomogram prognostic staging model was subsequently established for DFS and its precision was verified internally by the concordance index (C-Index) and externally by calibration curves. For OS, multivariate Cox regression analysis indicated Child-Pugh B7 score (HR 4.29; 95% CI 1.74-10.55; p = 0.002) as an independent prognostic factor, along with Barcelona Clinic Liver Cancer (BCLC) stage ≥ B (HR 1.95; 95% CI 1.07-3.54; p = 0.029), microvascular invasion (MVI) (HR 2.54; 95% CI 1.38-4.67; p = 0.003), R1/R2 resection margin (HR 1.57; 95% CI 0.85-2.90; p = 0.015), and Clavien-Dindo Grade 3 or more (HR 2.73; 95% CI 1.44-5.18; p = 0.002). For DFS, multivariate Cox regression analysis indicated BCLC stage ≥ B (HR 2.15; 95% CI 1.34-3.44; p = 0.002) as an independent prognostic factor, along with multiple nodules (HR 2.04; 95% CI 1.25-3.32; p = 0.004), MVI (HR 1.81; 95% CI 1.19-2.75; p = 0.005), satellite nodules (HR 1.63; 95% CI 1.09-2.45; p = 0.018), and R1/R2 resection margin (HR 3.39; 95% CI 2.19-5.25; < 0.001). The C-Index of the nomogram, tailored based on the previous significant factors, showed good accuracy (0.70). Internal and external calibration curves for the probability of DFS rate showed optimal consistency and fit well between the nomogram-based prediction and actual observations. MVI and R1/R2 resection margins should be considered as significant OS and DFS predictors, while satellite nodules should be included as a significant DFS predictor. The nomogram-based prognostic model for DFS provides a more effective prognosis assessment for resected HCC patients, allowing for individualized treatment plans.

The impact of hospital volume on liver resection: A systematic review and Bayesian network meta-analysis.

BACKGROUND: This study aims to compare the outcomes of high-volume, medium-volume, and low-volume hospitals performing hepatic resections using a network meta-analysis. METHODS: A literature search until June 2023 was conducted across major databases to identify studies comparing outcomes in high-volume, medium-volume, and low-volume hospitals for liver resection. Bayesian network meta-analysis was conducted, and surface under cumulative ranking area values, odds ratio, and mean difference with 95% credible intervals were reported for postoperative mortality, failure-to-rescue, morbidity, length of stay, and hospital costs. RESULTS: Twenty studies comprising 248,707 patients undergoing liver resection were included. For the primary mortality outcome, overall and subgroup analyses were performed: group I: high-volume = 5 to 20 resections/year; group II: high-volume = 21 to 49 resections/year; group III: high-volume ≥50 resections/year. Results demonstrated a significant association between hospital volume and mortality (overall-high-volume versus medium-volume: odds ratio 0.66, 95% credible interval 0.49-0.87; high-volume versus low-volume: odds ratio 0.52, 95% credible interval 0.41-0.65; group I-high-volume versus low-volume: odds ratio 0.34, 95% credible interval 0.22-0.50; medium-volume versus low-volume: odds ratio 0.56, 95% credible interval 0.33-0.92; group II-high-volume versus low-volume: odds ratio 0.67, 95% credible interval 0.45-0.91), as well as length of stay (high-volume versus low-volume: mean difference -1.24, 95% credible interval -2.07 to -0.41), favoring high-volume hospitals. No significant difference was observed in failure-to-rescue, morbidity, or hospital costs across the 3 groups. CONCLUSION: This study supports a positive relationship between hospital volume and surgical outcomes in liver resection. Patients from high-volume hospitals experience superior outcomes in terms of lower postoperative mortality and shorter lengths of stay than medium-volume and low-volume hospitals.

Preoperative Predictors of Early Recurrence After Liver Resection for Multifocal Hepatocellular Carcinoma.

BACKGROUND: Liver transplantation remains the optimal treatment for multifocal hepatocellular carcinoma (HCC). However, due to resource constrains, other therapeutic modalities such as liver resection (LR), are frequently utilized. LR, however, has to be balanced against potential morbidity and mortality along with the risks of early recurrence leading to futile surgery. In this study, we evaluated preoperative factors, including inflammatory indices, in predicting early (< 1 year) recurrence in patients who underwent LR for multifocal HCC. METHODS: This was a post hoc analysis of 250 consecutive patients with multifocal HCC who underwent LR. RESULTS: After exclusion of 10 patients with 30-day/in-hospital mortality, 240 were included of which 134 (55.8%) developed early recurrence. Hepatitis B/C aetiology, 3/ > more hepatic nodules and elevated alpha-fetoprotein (AFP) ≥ 200 ng/ml were significant independent preoperative predictors of early recurrence. The early recurrence rate was 72.1% when 2 out of 3 significant predictive factors were present. The conglomerate of all 3 factors predicted early recurrence of 100% with a statistically significant association between number of predictive factors and early recurrence (p < 0.001). CONCLUSION: Better patient selection via the use of preoperative predictive factors of early recurrence such as hepatitis B/C aetiology, ≥ 3 nodules and elevated AFP ≥ 200 ng/ml may assist in identifying patients in whom LR is deemed futile and improve resource allocation.

Intraoperative blood transfusion does not impact overall and recurrence-free survival after curative hepatectomy for hepatocellular carcinoma: A propensity-score-matched and inverse probability of treatment-weighted study.

INTRODUCTION: Our primary objective was to determine if receiving intraoperative blood transfusion was a significant prognostic factor for overall and recurrence-free survival after curative resection of hepatic cellular carcinoma (HCC). METHODOLOGY: Between 2001 and 2018, 1092 patients with histologically proven primary HCC who underwent curative liver resection were retrospectively reviewed. Primary study endpoints were recurrence-free survival (RFS) and overall survival (OS). The main analysis was undertaken using propensity-score matching (PSM) to minimize confounding and selection biases in the comparison of patients with or without transfusion. RESULTS: There were 220 patients who received and 666 patients who did not receive intraoperative blood transfusion. The PSM cohort consisted of 163 pairs of patients. After PSM, the only perioperative outcome that appeared to significantly affect whether patients would receive blood transfusion was median blood loss (p = 0.001). In the PSM cohort, whether patients received blood transfusion was neither associated with OS (p = 0.759) nor RFS (p = 0.830). When the volume of blood transfusion was analyzed as a continuous variable, no significant dose-response relationship between blood transfusion volume and HR for OS and RFS was noted. CONCLUSION: Intraoperative blood transfusion had no significant impact on the survival outcomes in patients who receive curative resection in primary HCC.

Association of standardized liver volume and body mass index with outcomes of minimally invasive liver resections.

INTRODUCTION: While minimally invasive liver resections (MILR) have demonstrated advantages in improved post-operative recovery, widespread adoption is hampered by inherent technical difficulties. Our study attempts to analyze the role of anthropometric measures in MILR-related outcomes. METHODS: Between 2012 and 2020, 676 consecutive patients underwent MILR at the Singapore General Hospital of which 565 met study criteria and were included. Patients were stratified based on Body Mass Index (BMI) as well as Standardized Liver Volumes (SLV). Associations between BMI and SLV to selected peri-operative outcomes were analyzed using restricted cubic splines. RESULTS: A BMI of ≥ 29 was associated with increase in blood loss [Mean difference (MD) 69 mls, 95% CI 2 to 137] as well as operative conversions [Relative Risk (RR) 1.63, 95% CI 1.02 to 2.62] among patients undergoing MILR while a SLV of 1600 cc or higher was associated with an increase in blood loss (MD 30 mls, 95% CI 10 to 49). In addition, a BMI of ≤ 20 was associated with an increased risk of major complications (RR 2.25, 95% 1.16 to 4.35). The magnitude of differences observed in these findings increased with each unit change in BMI and SLV. CONCLUSION: Both BMI and SLV were useful anthropometric measures in predicting peri-operative outcomes in MILR and may be considered for incorporation in future difficulty scoring systems for MILR.

Extending Surgical Resection for Hepatocellular Carcinoma Beyond Barcelona Clinic for Liver Cancer (BCLC) Stage A: A Novel Application of the Modified BCLC Staging System.

Objective: We aimed to prognosticate survival after surgical resection of HCC stratified by stage with amalgamation of the modified Barcelona Clinic Liver Cancer (BCLC) staging system and location of tumour. Methods: This single-institutional retrospective cohort study included patients with HCC who underwent surgical resection between 1st January 2000 to 30th June 2016. Participants were divided into 6 different subgroups: A-u) Within MC with Unilobar lesions; A-b) Within MC + Bilobar lesions; B1-u) Out of MC + within Up-To-7 + Unilobar lesions; B1-b) Out of MC + within Up-to-7 + Bilobar lesions; B2-u) Out of MC + Out of Up-To-7 + Unilobar lesions; B2-b) Out of MC + Out of Up-To-7 + Bilobar lesions. A separate survival analysis was conducted for solitary HCC lesions according to three subgroups: A-S (Within MC); B1-S (Out of MC + within Up-To-7); B2-S (Out of MC + out of Up-To-7). Results: A total of 794 of 1043 patients with surgical resection for HCC were analysed. Groups A-u (64.6%), A-b (58.4%) and B1-u (56.2%) had 5-year cumulative overall survival (OS) rates above 50% after surgical resection and median OS exceeding 60 months (P = 0.0001). The 5-year cumulative recurrence-free survival rates (RFS) were 40.4% (group A-u), 38.2% (group A-b), 36.3% (group B1-u), 24.6% (group B2-u), and 7.3% (group B2-b)(P=0.0001). For solitary lesions, the 5-year OS for the subgroups were A-S (65.1%), B1-S (56.0%) and B2-S (47.1%) (P = 0.0003). Compared to A-S, there was also a significant trend towards relatively poorer OS as the lesion sizes increased in B1-S (HR 1.46, 95% CI 1.03-2.08) and B2-S (HR 1.65, 95% CI 1.25-2.18). Conclusion: We adopted a novel approach combining the modified BCLC B sub-classification and dispersion of tumour to show that surgical resection in intermediate stage HCC can be robustly prognosticated. We found that size prognosticates resection outcomes in solitary tumours.

Poor utility of current nomograms assessing the risk of intraoperative blood transfusion in patients undergoing liver resection for hepatocellular carcinoma and proposal of a new model.

BACKGROUND: The Memorial Sloan Kettering Cancer Center nomogram, the predictive scoring system of Yamamoto et al, and the 3-point transfusion risk score of Lemke et al are models used to determine the probability of receiving intraoperative blood transfusion in patients undergoing liver resection. However, the external validity of these models remains unknown. The objective of this study was to evaluate their predictive performance in an external cohort of patients with hepatocellular carcinoma. We also aimed to identify predictors of blood transfusion and develop a new predictive model for blood transfusion. METHODS: Post hoc analysis of our prospective database of 1,081 patients undergoing liver resection for hepatocellular carcinoma from 2001 to 2018. The predictive performance of current prediction models was evaluated using C statistics. Demographic and clinical variables as predictors of blood transfusion were assessed. Using logistic regression, an alternative model was created. RESULTS: The Lemke transfusion risk score performed better than the Memorial Sloan Kettering Cancer Center nomogram (0.69, 95% confidence interval 0.66-0.73 vs 0.66, 95% liver resection 0.62-0.69) (P < .001). The model from Yamamoto et al performed comparably with no statistically significant differences found through pairwise comparison. In our alternative model, hemoglobin level, albumin level, liver resection type, and tumor size were independent predictors of blood transfusion. The new HATS model obtained a C statistic of 0.74 (95% confidence interval 0.71-0.78), performing significantly better than the previous 3 models (P ≤ 0.001 for all). CONCLUSION: The existing Memorial Sloan Kettering Cancer Center, Yamamoto et al, and Lemke et al had nomograms with the suboptimal accuracy of predicting risk of intraoperative blood transfusion in patients undergoing liver resection for hepatocellular carcinoma. The proposed HATS model was more accurate at predicting patients at risk of blood transfusion.

Minimally Invasive vs Open Major Hepatectomies for Liver Malignancies: a Propensity Score-Matched Analysis.

BACKGROUND: The majority of evidence with regards to minimally invasive liver resection (MILR) favors its application in minor hepatectomies. We conducted a propensity score-matched (PSM) analysis to determine its feasibility and safety in major hepatectomies (MIMH) for liver malignancies. METHODS: Retrospective review of 130 patients who underwent MIMH and 490 patients who underwent open major hepatectomy (OMH) for malignant pathologies was performed. PSM in a 1:1 ratio identified two groups of patients with similar baseline clinicopathological characteristics. Perioperative outcomes were then compared. Major hepatectomies included traditional major (>3 segments) and technical major hepatectomies (right anterior and right posterior sectionectomies). RESULTS: Both cohorts were well-matched for baseline characteristics after PSM. Of 130 MIMH cases, there were 12 conversions to open. Comparison of perioperative outcomes demonstrated a significant association of MIMH with longer operation time and more frequent application of Pringle's maneuver (PM), but decreased postoperative stay. These results were consistent on a subgroup analysis that only included patients undergoing traditional major hepatectomies. A second subgroup analysis restricted to cirrhotic patients demonstrated that while perioperative outcomes were equivalent, MIMH was similarly associated with a longer operative time. Subset analyses of resections performed after 2015 demonstrated that MIMH was additionally associated with a lower postoperative morbidity compared to OMH. CONCLUSION: Comparison of perioperative and short-term oncological outcomes between MIMH and OMH for malignancies demonstrated that MIMH is feasible and safe. It is associated with a shorter hospital stay at the expense of a longer operation time compared to OMH.

Effect of age on the short- and long-term outcomes of patients undergoing curative liver resection for HCC.

BACKGROUND: Few studies have evaluated the outcomes of curative liver resection (LR) in octogenarian patients, analysed cancer-specific survival (CSS) with HCC-related death or explored the age-varying effect of HCC-related death in elderly patients undergoing LR. We aim to determine the effect of age on the short and long-term outcomes of LR for HCC. METHODOLOGY: Between 2000 and 2018, 1,092 patients with primary HCC who underwent LR with curative intent were retrospectively reviewed. The log-rank test and Gray's test were used to assess the equality of survivor functions and competing risk-adjusted cumulative incidence functions between patients in the three age categories respectively. Regression adjustment was used to control for confounding bias via a Principal Component Analysis. Quantile, Firth logistic, Cox, and Fine-Gray competing risk regression were used to analyse continuous, binary, time-to-event, and cause-specific survival respectively. Restricted cubic splines were used to illustrate the dose-effect relationship between age and patient outcomes. RESULTS: The study comprised of 764 young patients (<70 years), 278 septuagenarians (70-79 years old) and 50 octogenarians (≥80 years). Compared to young patients, octogenarians had significantly lower 5-year OS(62.1% vs 37.7%, p < 0.001). However, there was no significant difference in 1-year RFS(73.1% vs 67.0%, p = 0.774) or 5-year CSS (5.4% vs 15.2%, p = 0.674). Every 10-year increase in age was significantly associated with an increase length of stay (p < 0.001), postoperative complications (p = 0.004) and poorer OS(p = 0.018) but not significantly associated with major complications (p = 0.279), CSS(p = 0.338) or RFS(p = 0.941). CONCLUSION: Age by itself was associated with OS after LR for HCC but was not a significant risk factor for HCC-related death.

Impact of non-liver-related previous abdominal surgery on the difficulty of minimally invasive liver resections: a propensity score-matched controlled study.

INTRODUCTION: The presence of previous abdominal surgery (PAS) has traditionally been considered to add difficulty to and increase risk of complications of laparoscopic procedures. This study aims to analyse the impact of non-liver-related PAS on the difficulty of minimally invasive liver resections (MILRs). MATERIALS AND METHODS: After exclusion of patients with concomitant major surgical procedures as well as previous liver resections, 515 consecutive patients undergoing MILR in Singapore General Hospital from 2006 to 2019 were analysed, consisting of 161 MILR in patients with previous abdominal surgery (WPAS) and 354 MILR in patients without previous abdominal surgery (WOPAS). Propensity score-matched (PSM) comparison was performed between WPAS and WOPAS groups. In addition, subgroup analysis was made comparing previous upper or lower abdominal surgery and open versus minimally invasive approach of PAS. Outcomes measured include those associated with operative difficulty such as open conversion rates, operative time, blood loss, as well as morbidity and mortality rates. RESULTS: MILR outcomes in patients WPAS are not inferior to those WOPAS. Overall open conversion rate was 8.2%, higher in patients WOPAS compared to patients WPAS (11.9% versus 3.5%, p = 0.015). Operating time (p = 0.942), blood loss (p = 0.063), intraoperative blood transfusion (p = 0.750), length of hospital stay (p = 0.206), morbidity (p = 0.217) and 30- and 90-day mortality (p = 1 & p = 0.367) were comparable between the two groups and subgroup analysis. CONCLUSION: Outcomes of MILR in patients with previous non-liver-related abdominal surgery are not inferior to patients without previous abdominal surgery.

Propensity-Score Matched Analyses Comparing Clinical Outcomes of Minimally Invasive Versus Open Distal Pancreatectomies: A Single-Center Experience.

BACKGROUND: Minimally invasive distal pancreatectomy (MIDP) is being adopted increasingly worldwide. This study aimed to compare the short-term outcomes of patients who underwent MIDP versus open distal pancreatectomy (ODP). METHODS: A retrospective review of all patients who underwent a DP in our institution between 2005 and 2019 was performed. Propensity score matching based on relevant baseline factors was used to match patients in the ODP and MIDP groups in a 1:1 manner. Outcomes reported include operative duration, blood loss, postoperative length of stay, morbidity, mortality, postoperative pancreatic fistula rates, reoperation and readmission. RESULTS: In total, 444 patients were included in this study. Of 122 MIDP patients, 112 (91.8%) could be matched. After matching, the median operating time for MIDP was significantly longer than ODP [260 min (200-346.3) vs 180 (135-232.5), p < 0.001], while postoperative stay for MIDP was significantly shorter [median 6 days (5-8) versus 7 days (6-9), p = 0.015]. There were no significant differences noted in any of the other outcomes measured. Over time, we observed a decrease in the operation times of MIDP performed at our institution. CONCLUSION: Adoption of MIDP offers advantages over ODP in terms of a shorter postoperative hospital stay, without an increase in morbidity and/or mortality but at the expense of a longer operation time.

Impact of tumor size on the difficulty of minimally invasive liver resection.

INTRODUCTION: We performed this study in order to investigate the impact of tumour size on the difficulty of MILR, as well as to elucidate the optimal tumour size cut-off/s to distinguish between 'easy' and 'difficult' MILRs. MATERIALS AND METHODS: This is retrospective review of 603 consecutive patients who underwent MILR between 2006 and 2019 of which 461 met the study inclusion criteria. We first conducted an exploratory analysis to visualize the associations between tumor size and various surrogates of laparoscopic difficulty in order to determine to optimal tumor size cutoff for stratification. Visual inspection of flexible spline-based models as well as quantitative evidence determined that perioperative outcomes differed between patients with tumor size of 30-69 mm and tumours ≥70 mm. These cutoffs were used for further downstream analyses. RESULTS: The cohort of 461 patients was divided into 3 groups based on tumour diameter size. Patients with larger tumours experienced longer operating times ((PGroup 2 vs 1<0.001, PGroup 3 vs 1<0.001, PGroup 3 vs 2<0.001), higher blood loss (PGroup 2 vs 1<0.001, PGroup 3 vs 1<0.001, PGroup 3 vs 2<0.001), as well as significantly longer hospital stay (PGroup 2 vs 1<0.001, PGroup 3 vs 1<0.001, PGroup 3 vs 2<0.001). There was a monotonic trend towards increasing blood transfusion rates (P = 0.006), overall morbidity (P = 0.029) and 90-day mortality rates (P = 0.047) with increasing tumour size. CONCLUSION: Although tumour size of 30 mm serves as an optimal cut-off for predicting difficult resections as per the Iwate criteria, a trichotomy (<30 mm, 30-69 mm, ≥70 mm) may provide additional granularity. Further large-scale prospective studies are needed to corroborate these findings.

Preoperative predictors of early recurrence of AJCC T4 hepatocellular carcinoma.

BACKGROUND: The management of HCC differs depending on the extent of disease. Surgery may be offered in selected cases of T4 disease as defined by AJCC 8th. However, outcome data post partial hepatectomy (PH) for T4 disease is scarce. We sought to evaluate the outcomes of patients post resection of T4 HCC and assess preoperative predictive factors of early recurrence. METHODS: We performed a retrospective review of 235 consecutive patients who underwent resection for T4 HCC from 2001 to 2018 at our institution. RESULTS: Median overall survival was 35.9 months (95% CI 25.7-46.0). 109 patients (49.5%) developed recurrence, of which 94 patients (42.7%) experienced early recurrence within 12 months. Median time to recurrence was 38.1 months. Multivariate analysis demonstrated that vascular invasion were significant independent preoperative predictor of early recurrence post resection. Patients who experienced early recurrence had a significantly shorter median overall survival 14.3 months (95% CI 25.7-46.0) compared to those who did not (55.5 months, 95% CI 40.6-70.8, p = .000). CONCLUSION: Selected patients with T4 HCC may benefit from PH. Macrovascular invasion was associated with early recurrence within 12 months.

Comparison between short and long-term outcomes after minimally invasive versus open primary liver resections for hepatocellular carcinoma: A 1:1 matched analysis.

BACKGROUND: This study aims to compare the short- and long-term outcomes of patients undergoing minimally invasive liver resection (MILR) versus open liver resection (OLR) for nonrecurrent hepatocellular carcinoma (HCC). METHODS: Review of 204 MILR and 755 OLR without previous LR performed between 2005 and 2018. 1:1 coarsened exact matching (CEM) and 1:1 propensity-score matching (PSM) were performed. RESULTS: Overall, 190 MILR were well-matched with 190 OLR by PSM and 86 MILR with 86 OLR by CEM according to patient baseline characteristics. After PSM and CEM, MILR was associated with a significantly longer operation time [230 min (interquartile range [IQR], 145-330) vs. 160 min (IQR, 125-210), p < .001] [215 min (IQR, 135-295) vs. 153.5 min (120-180), p < .001], shorter postoperative stay [4 days (IQR, 3-6) vs. 6 days (IQR, 5-8), p = .001)] [4 days (IQR, 3-5) vs. 6 days (IQR, 5-7), p = .004] and lower postoperative morbidity [40 (21%) vs. 67 (35.5%), p = .003] [16 (18.6%) vs. 27 (31.4%), p = .036] compared to OLR. MILR was also associated with a significantly longer median time to recurrence (70 vs. 40.3 months, p = .014) compared to OLR after PSM but not CEM. There was no significant difference in terms of overall survival and recurrence-free survival. CONCLUSION: MILR is associated with superior short-term postoperative outcomes and with at least equivalent long-term oncological outcomes compared to OLR for HCC.

Continuous improvements in short and long-term outcomes after partial hepatectomy for hepatocellular carcinoma in the 21st century: Single institution experience with 1300 resections over 18 years.

INTRODUCTION: To investigate the changing trends in short- and long-term outcomes after partial hepatectomy(PH) for hepatocellular carcinoma(HCC) performed in the 21st century. METHODS: A retrospective review was conducted on 1300 consecutive patients who underwent PH for HCC. The study cohort was divided into 3 time periods(P): P1(2000-2005), P2(2006-2011) and P3(20012-2017). RESULTS: Comparison between the patients' baseline demographic features across the 3 periods demonstrated that patients were significantly older, had decreasing frequency of hepatitis B, increasing non-alcoholic fatty liver disease, lower alpha-feto protein(AFP) level, lower creatinine levels, less likely to undergo emergency surgery, less likely to undergo major hepatectomy, more likely to undergo repeat resection and minimally-invasive surgery. There was also an increase in operation time, decrease in blood loss, increase frequency in the use of Pringles manoeuvre, decrease liver failure, decrease length of stay and decrease postoperative mortality. HCC resected were of smaller size, less likely to demonstrate microvascular invasion and less likely to have close margins. This was associated with significant improvement in overall survival and recurrence free interval over time. Period of resection was an independent predictor of 90-day mortality and OS on multivariate analysis. CONCLUSION: We observed a continuous improvement in postoperative outcomes including postoperative mortality and long-term survival after PH for HCC over the past 18 years.

Elevated Right Hemidiaphragm: A Clue in Acute Cholecystitis?

Two patients presented to the Emergency Department with sepsis and vague localising complaints. Both of them had a new elevation of the right hemidiaphragm on chest radiography and were eventually diagnosed with complicated acute cholecystitis on CT imaging. In both cases, the hemidiaphragmatic elevation could not be explained by mass effect as there was no sizable intra-abdominal collection. One of the patients was initially misdiagnosed with pneumonia, resulting in clinical deterioration due to delay in definitive management. Awareness of this phenomenon is essential to avoid pitfalls in patients with acute cholecystitis, especially for those who do not present in a typical manner.