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.

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.

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.

Differential involvement of mitochondria in post-tetanic potentiation at intracortical excitatory synapses of the medial prefrontal cortex.

Post-tetanic Ca2+ release from mitochondria produces presynaptic residual calcium, which contributes to post-tetanic potentiation. The loss of mitochondria-dependent post-tetanic potentiation is one of the earliest signs of Alzheimer's model mice. Post-tetanic potentiation at intracortical synapses of medial prefrontal cortex has been implicated in working memory. Although mitochondrial contribution to post-tetanic potentiation differs depending on synapse types, it is unknown which synapse types express mitochondria-dependent post-tetanic potentiation in the medial prefrontal cortex. We studied expression of mitochondria-dependent post-tetanic potentiation at different intracortical synapses of the rat medial prefrontal cortex. Post-tetanic potentiation occurred only at intracortical synapses onto layer 5 corticopontine cells from commissural cells and L2/3 pyramidal neurons. Among post-tetanic potentiation-expressing synapses, L2/3-corticopontine synapses in the prelimbic cortex were unique in that post-tetanic potentiation depends on mitochondria because post-tetanic potentiation at corresponding synapse types in other cortical areas was independent of mitochondria. Supporting mitochondria-dependent post-tetanic potentiation at L2/3-to-corticopontine synapses, mitochondria-dependent residual calcium at the axon terminals of L2/3 pyramidal neurons was significantly larger than that at commissural and corticopontine cells. Moreover, post-tetanic potentiation at L2/3-corticopontine synapses, but not at commissural-corticopontine synapses, was impaired in the young adult Alzheimer's model mice. These results would provide a knowledge base for comprehending synaptic mechanisms that underlies the initial clinical signs of neurodegenerative disorders.

Angiotensin receptor blockers, but not angiotensin-converting enzyme inhibitors, inhibit abnormal bone changes in spondyloarthritis.

Spondyloarthritis (SpA) is a chronic inflammatory disease that results in bone ankylosis. The tissue renin-angiotensin system (RAS) is an emerging pathway potentially implicated in SpA-associated bone changes. The aim of the present study was to determine the mechanisms underlying this relationship. Sakaguchi (SKG) mice injected with curdlan (SKGc), animal models for SpA, were treated with RAS modulators, angiotensin II receptor blockers (ARBs) or angiotensin-converting enzyme inhibitors (ACEis). Disease activity was assessed using clinical scores and computed tomography scans. Mouse primary bone marrow monocytes (BMMs), osteoblast (OB) progenitor cells, peripheral blood monocytes (PBMCs), and bone-derived cells (BdCs) from patients with radiographic axial SpA (r-axSpA) were used to investigate the role of RAS in SpA pathogenesis. The expression of RAS components was significantly increased in SKGc mouse joints, and ARBs significantly reduced erosion and systemic bone loss, whereas ACEis did not. Osteoclast (OC) differentiation from primary BMMs, mediated by TRAF6, was inhibited by ARBs but promoted by ACEis; the modulators also exerted opposite effects on OB differentiation. Expression of RAS molecules was higher in PBMCs and BdCs of patients with r-axSpA than in control participants. ARBs inhibited OB differentiation in the BdCs of patients with r-axSpA, whereas ACEis did not. Neither ARBs nor ACEis affected OB differentiation in the control participants. In SpA, a condition characterized by RAS overexpression, ARBs, but not ACEis, inhibited OC and OB differentiation and bone progression. The findings should be taken into account when treating patients with SpA using RAS modulators.

Enhancement of Hip X-ray with Convolutional Autoencoder for Increasing Prediction Accuracy of Bone Mineral Density.

It is very important to keep track of decreases in the bone mineral density (BMD) of elderly people since it can be correlated with the risk of incidence of major osteoporotic fractures leading to fatal injuries. Even though dual-energy X-ray absorptiometry (DXA) is the one of the most precise measuring techniques used to quantify BMD, most patients have restricted access to this machine due to high cost of DXA equipment, which is also rarely distributed to local clinics. Meanwhile, the conventional X-rays, which are commonly used for visualizing conditions and injuries due to their low cost, combine the absorption of both soft and bone tissues, consequently limiting its ability to measure BMD. Therefore, we have proposed a specialized automated smart system to quantitatively predict BMD based on a conventional X-ray image only by reducing the soft tissue effect supported by the implementation of a convolutional autoencoder, which is trained using proposed synthesized data to generate grayscale values of bone tissue alone. From the enhanced image, multiple features are calculated from the hip X-ray to predict the BMD values. The performance of the proposed method has been validated through comparison with the DXA value, which shows high consistency with correlation coefficient of 0.81 and mean absolute error of 0.069 g/cm2.

Machine Learning-Based Measurement of Regional and Global Spinal Parameters Using the Concept of Incidence Angle of Inflection Points.

This study delves into the application of convolutional neural networks (CNNs) in evaluating spinal sagittal alignment, introducing the innovative concept of incidence angles of inflection points (IAIPs) as intuitive parameters to capture the interplay between pelvic and spinal alignment. Pioneering the fusion of IAIPs with machine learning for sagittal alignment analysis, this research scrutinized whole-spine lateral radiographs from hundreds of patients who visited a single institution, utilizing high-quality images for parameter assessments. Noteworthy findings revealed robust success rates for certain parameters, including pelvic and C2 incidence angles, but comparatively lower rates for sacral slope and L1 incidence. The proposed CNN-based machine learning method demonstrated remarkable efficiency, achieving an impressive 80 percent detection rate for various spinal angles, such as lumbar lordosis and thoracic kyphosis, with a precise error threshold of 3.5°. Further bolstering the study's credibility, measurements derived from the novel formula closely aligned with those directly extracted from the CNN model. In conclusion, this research underscores the utility of the CNN-based deep learning algorithm in delivering precise measurements of spinal sagittal parameters, and highlights the potential for integrating machine learning with the IAIP concept for comprehensive data accumulation in the domain of sagittal spinal alignment analysis, thus advancing our understanding of spinal health.

Robotic central pancreatectomy: a surgical technique.

Robotic central pancreatectomy has not been widely performed because of its rare indications, technical difficulties, and concern about the high complication rate. We reviewed six robotic central pancreatectomy cases between May 2016 and June 2021 at a single institution. This multimedia article aims to introduce our technique of robotic central pancreatectomy with perioperative and follow-up outcomes. All patients experienced biochemical leakage of postoperative pancreatic fistula, except in one with a grade B pancreatic fistula, which resulted in a pseudocyst formation and was successfully managed by endoscopic internal drainage. All patients achieved completely negative resection margins. There was no new-onset diabetes mellitus or recurrence during the median follow-up period of 13.5 months (range, 10-74 months). With an acceptable complication rate and the preservation of pancreatic function, robotic central pancreatectomy could be a good surgical option for patients with benign and borderline malignant tumors of the pancreatic neck or proximal body.

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.

Residents perform better technically, have less stress and workload, and prefer robotic to laparoscopic technique during inanimate simulation.

INTRODUCTION: With the widespread adoption of minimally invasive surgery, there is a growing need for surgical residents to be trained by a procedure-specific curriculum. This study aimed to evaluate the technical performance and feedback of surgical residents undergoing the robotic and laparoscopic hepaticojejunostomy (HJ) and gastrojejunostomy (GJ) biotissue modules. METHODS: A total of 23 PGY-3 surgical residents participated in this study and performed the laparoscopic and robotic HJ and GJ drills, which were recorded and scored by two independent graders using the modified objective structured assessment of technical skills (OSATS). After completing each drill, all participants filled out the NASA Task Load Index (NASA-TLX), Borg Exertion Scale, and Edwards Arousal Rating Questionnaire. RESULTS: Twenty-two (95.7%) residents had already received fundamentals of laparoscopic surgery certification. Eighteen (78.3%) residents had robotic virtual simulation training and the median (range) number of robotic surgery console experience was 4 (0-30). In the HJ comparison of the six OSATS domains, the robotic system was superior in Gentleness (p = 0.031). In the GJ comparison, the robotic system was superior in Time and Motion (p < 0.001), Instrument Handling (p = 0.001), Flow of Operation (p = 0.002), Tissue Exposure (p = 0.013), and Summary (p < 0.001). Participants answered significantly higher demand scores for laparoscopy on all six facets of NASA-TLX for both HJ and GJ (p < 0.05). The Borg Level of Exertion was > 2 points higher for laparoscopic HJ and GJ (p < 0.001). Residents rated more Nervousness and Anxiety for laparoscopic compared to robotic (p < 0.05) HJ and GJ. Additionally, when asked to score preference for robotic and laparoscopic approach in terms of technique and ergonomics, residents scored robot as better (laparoscopy worse) for both HJ and GJ in both domains. CONCLUSIONS: The robotic surgical system provided a more favorable environment for trainees with less mental and physical burden for minimally invasive HJ and GJ curriculum.

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 adjuvant therapy in patients with invasive intraductal papillary mucinous neoplasms of the pancreas: an international multicenter cohort study.

BACKGROUND: Adjuvant therapy prolongs survival in patients with pancreatic ductal adenocarcinoma. However, no clear guidelines are available regarding the oncologic effects of adjuvant therapy (AT) in resected invasive intraductal papillary mucinous neoplasms (IPMN). The aim was to investigate the potential role of AT in patients with resected invasive IPMN. MATERIALS AND METHODS: From 2001 to 2020, 332 patients with invasive pancreatic IPMN were retrospectively reviewed in 15 centres in eight countries. Propensity score-matched and stage-matched survival analyses were conducted. RESULTS: A total of 289 patients were enroled in the study after exclusion (neoadjuvant therapy, unresectable disease, uncertain AT status, and stage IV). A total of 170 patients were enroled in a 1:1 propensity score-matched analysis according to the covariates. In the overall cohort, disease-free survival was significantly better in the surgery alone group than in the AT group ( P =0.003), but overall survival (OS) was not ( P =0.579). There were no significant differences in OS in the stage-matched analysis between the surgery alone and AT groups (stage I, P =0.402; stage II, P =0.179). AT did not show a survival benefit in the subgroup analysis according to nodal metastasis (N0, P =0.481; N+, P =0.705). In multivariate analysis, node metastasis (hazard ratio, 4.083; 95% CI, 2.408-6.772, P <0.001), and cancer antigen 19-9 greater than or equal to 100 (hazard ratio, 2.058; 95% CI, 1.247-3.395, P =0.005) were identified as adverse prognostic factors in resected invasive IPMN. CONCLUSION: The current AT strategy may not be recommended to be performed with resected invasive IPMN in stage I and II groups, unlike pancreatic ductal adenocarcinoma. Further investigations of the potential role of AT in invasive IPMN are recommended.

Laparoscopic pancreaticoduodenectomy and laparoscopic pancreaticoduodenectomy with robotic reconstruction: single-surgeon experience and technical notes.

Purpose: Despite the increasing number of robotic pancreaticoduodenectomies, laparoscopic pancreaticoduodenectomy (LPD) and LPD with robotic reconstruction (LPD-RR) are still valuable surgical options for minimally invasive pancreaticoduodenectomy (MIPD). This study introduces the surgical techniques, tips, and outcomes of our experience with LPD and LPD-RR. Methods: Between March 2014 and July 2021, 122 and 48 patients underwent LPD and LPD-RR respectively, at CHA Bundang Medical Center in Korea. The operative settings, procedures, and trocar placements were identical in both approaches; however, different trocars were used. We introduced our techniques of retraction methods for Kocherization and uncinate process dissection, pancreatic reconstruction, pancreatic division, and protection using the round ligament. The perioperative surgical outcomes of LPD and LPD-RR were compared. Results: Baseline demographics of patients in the LPD and LPD-RR groups were comparable, but the LPD group had older age (65.5 ± 11.6 years vs. 60.0 ± 14.1 years, p = 0.009) and lesser preoperative chemotherapy (15.6% vs. 35.4%, p = 0.008). The proportion of malignant disease was similar (LPD group, 86.1% vs. LPD-RR group, 83.3%; p = 0.759). Perioperative outcomes were also comparable, including operative time, estimated blood loss, clinically relevant postoperative pancreatic fistula (LPD group, 9.0% vs. LPD-RR group, 10.4%; p = 0.684), and major postoperative complication rates (LPD group, 14.8% vs. LPD-RR group, 6.2%; p = 0.082). Conclusion: Both LPD and LPR-RR can be safely performed by experienced surgeons with acceptable surgical outcomes. Further investigations are required to evaluate the objective benefits of robotic surgical systems in MIPD and establish widely acceptable standardized MIPD techniques.

Correlation between Harris hip score and gait analysis through artificial intelligence pose estimation in patients after total hip arthroplasty.

BACKGROUND: Recently, open pose estimation using artificial intelligence (AI) has enabled the analysis of time series of human movements through digital video inputs. Analyzing a person's actual movement as a digitized image would give objectivity in evaluating a person's physical function. In the present study, we investigated the relationship of AI camera-based open pose estimation with Harris Hip Score (HHS) developed for patient-reported outcome (PRO) of hip joint function. METHOD: HHS evaluation and pose estimation using AI camera were performed for a total of 56 patients after total hip arthroplasty in Gyeongsang National University Hospital. Joint angles and gait parameters were analyzed by extracting joint points from time-series data of the patient's movements. A total of 65 parameters were from raw data of the lower extremity. Principal component analysis (PCA) was used to find main parameters. K-means cluster, X-squared test, Random forest, and mean decrease Gini (MDG) graph were also applied. RESULTS: The train model showed 75% prediction accuracy and the test model showed 81.8% reality prediction accuracy in Random forest. "Anklerang_max", "kneeankle_diff", and "anklerang_rl" showed the top 3 Gini importance score in the Mean Decrease Gini (MDG) graph. CONCLUSION: The present study shows that pose estimation data using AI camera is related to HHS by presenting associated gait parameters. In addition, our results suggest that ankle angle associated parameters could be key factors of gait analysis in patients who undergo total hip arthroplasty.

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.

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.

ARID1A Mutation from Targeted Next-Generation Sequencing Predicts Primary Resistance to Gemcitabine and Cisplatin Chemotherapy in Advanced Biliary Tract Cancer.

PURPOSE: There are clinical unmet needs in predicting therapeutic response and precise strategy for the patient with advanced biliary tract cancer (BTC). We aimed to identify genomic alterations predicting therapeutic response and resistance to gemcitabine and cisplatin (Gem/Cis)-based chemotherapy in advanced BTC. MATERIALS AND METHODS: Genomic analysis of advanced BTC multi-institutional cohorts was performed using targeted panel sequencing. Genomic alterations were analyzed integrating patients' clinicopathologic data, including clinical outcomes of Gem/Cis-based therapy. Significance of genetic alterations was validated using clinical next-generation sequencing (NGS) cohorts from public repositories and drug sensitivity data from cancer cell lines. RESULTS: 193 BTC patients from three cancer centers were analyzed. Most frequent genomic alterations were TP53 (55.5%), KRAS (22.8%), ARID1A (10.4%) alterations, and ERBB2 amplification (9.8%). Among 177 patients with BTC receiving Gem/Cis-based chemotherapy, ARID1A alteration was the only independent predictive molecular marker of primary resistance showing disease progression for 1st-line chemotherapy in the multivariate regression model (odds ratio, 3.12; p=0.046). In addition, ARID1A alteration was significantly correlated with inferior progression-free survival on Gem/Cis-based chemotherapy in the overall patient population (p=0.033) and in patients with extrahepatic cholangiocarcinoma (CCA) (p=0.041). External validation using public repository NGS revealed that ARID1A mutation was a significant predictor for poor survival in BTC patients. Investigation of multi-OMICs drug sensitivity data from cancer cell lines revealed that cisplatin-resistance was exclusively observed in ARID1A mutant bile duct cancer cells. CONCLUSION: Integrative analysis with genomic alterations and clinical outcomes of the first-line Gem/Cis-based chemotherapy in advanced BTC revealed that patients with ARID1Aalterations showed a significant worse clinical outcome, especially in extrahepatic CCA. Well-designed prospective studies are mandatory to validate the predictive role of ARID1Amutation.

Robotic versus laparoscopic liver resection for huge (≥10 cm) liver tumors: an international multicenter propensity-score matched cohort study of 799 cases.

Background: The use of laparoscopic (LLR) and robotic liver resections (RLR) has been safely performed in many institutions for liver tumours. A large scale international multicenter study would provide stronger evidence and insight into application of these techniques for huge liver tumours ≥10 cm. Methods: This was a retrospective review of 971 patients who underwent LLR and RLR for huge (≥10 cm) tumors at 42 international centers between 2002-2020. Results: One hundred RLR and 699 LLR which met study criteria were included. The comparison between the 2 approaches for patients with huge tumors were performed using 1:3 propensity-score matching (PSM) (73 vs. 219). Before PSM, LLR was associated with significantly increased frequency of previous abdominal surgery, malignant pathology, liver cirrhosis and increased median blood. After PSM, RLR and LLR was associated with no significant difference in key perioperative outcomes including media operation time (242 vs. 290 min, P=0.286), transfusion rate rate (19.2% vs. 16.9%, P=0.652), median blood loss (200 vs. 300 mL, P=0.694), open conversion rate (8.2% vs. 11.0%, P=0.519), morbidity (28.8% vs. 21.9%, P=0.221), major morbidity (4.1% vs. 9.6%, P=0.152), mortality and postoperative length of stay (6 vs. 6 days, P=0.435). Conclusions: RLR and LLR can be performed safely for selected patients with huge liver tumours with excellent outcomes. There was no significant difference in perioperative outcomes after RLR or LLR.

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.