Laparoscopically Limited Anatomic Liver Resections: A Single-Center Analysis for Oncologic Outcomes of the Conceptual Procedure.

BACKGROUND: Limited anatomic resections (LARs), such as segmentectomies, performed using a fully laparoscopic approach, have gained popularity for liver malignancies. However, the oncologic efficacy of laparoscopic LARs (Lap-LARs) needs further investigation. This cohort study evaluated the oncologic outcomes of Lap-LAR for hepatocellular carcinoma (HCC) and colorectal liver metastasis (CRLM). METHODS: At a Japanese referral center, 112 patients underwent Lap-LAR using the Glissonean approach and indocyanine green (ICG) fluorescence navigation. Recurrence-free survival (RFS), overall survival (OS), time to interventional failure (TIF), and time to surgical failure (TSF) were assessed. RESULTS: Among the 112 patients (median age, 74 years [range, 66-80 years]; 80 men [71.4 %]), Lap-LAR showed promising results. The median operative time was 348 min (range, 280-460 min), and the median blood loss was 190 mL (range, 95.5-452.0 mL). The median error between the estimated and actual liver volumes was 2 % (1.2-4.8 %). Complications greater than Clavien-Dindo 3a were observed in 11.6 % of the patients. The 5-year RFS, OS, and TIF rates for HCC were 45.1 % ± 7.9 %, 73.1 % ± 6.7 %, and 74.2 % ± 6 .6 %, respectively. The 5-year RFS, OS, and TSF rates for CRLM were 36.8 % ± 8.7 %, 60.1 % ± 13.3 %, and 63.6 % ± 10.4 %, respectively. CONCLUSIONS: Lap-LAR showed favorable oncologic outcomes for HCC and CRLM. Its precise technique makes it a promising therapeutic option for liver malignancies. Further comparisons with conventional approaches are warranted.

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.

Explainable artificial intelligence prediction-based model in laparoscopic liver surgery for segments 7 and 8: an international multicenter study.

BACKGROUND: Artificial intelligence (AI) is becoming more useful as a decision-making and outcomes predictor tool. We have developed AI models to predict surgical complexity and the postoperative course in laparoscopic liver surgery for segments 7 and 8. METHODS: We included patients with lesions located in segments 7 and 8 operated by minimally invasive liver surgery from an international multi-institutional database. We have employed AI models to predict surgical complexity and postoperative outcomes. Furthermore, we have applied SHapley Additive exPlanations (SHAP) to make the AI models interpretable. Finally, we analyzed the surgeries not converted to open versus those converted to open. RESULTS: Overall, 585 patients and 22 variables were included. Multi-layer Perceptron (MLP) showed the highest performance for predicting surgery complexity and Random Forest (RF) for predicting postoperative outcomes. SHAP detected that MLP and RF gave the highest relevance to the variables "resection type" and "largest tumor size" for predicting surgery complexity and postoperative outcomes. In addition, we explored between surgeries converted to open and non-converted, finding statistically significant differences in the variables "tumor location," "blood loss," "complications," and "operation time." CONCLUSION: We have observed how the application of SHAP allows us to understand the predictions of AI models in surgical complexity and the postoperative outcomes of laparoscopic liver surgery in segments 7 and 8.

Combining preoperative C-reactive protein values with the Tokyo Guidelines 2018 grading criteria can enhance the prediction of surgical difficulty in early laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND: Early laparoscopic cholecystectomy (ELC) is the standard treatment for acute cholecystitis (AC). However, predicting the difficulty of this procedure remains challenging. The present study aimed to develop an improved prediction model for surgical difficulty during ELC, surpassing the current Tokyo Guidelines 2018 (TG18) grading system. METHODS: We analyzed data from 201 consecutive patients who underwent ELC for AC between 2019 and 2021. Surgical difficulty was defined as the failure to achieve the critical view of safety (non-CVS). We developed a scoring system by conducting multivariate analysis on demographics, symptoms, laboratory data, and radiographic findings. The predictive accuracy of our scoring system was compared to that of the TG18 grading system (Grade I vs. Grade II/III). RESULTS: Through multivariate logistic regression analysis, a novel scoring system was formulated. This system incorporated preoperative C-reactive protein (CRP) values (≥5: 1 pt, ≥10: 2 pts, ≥15: 3 pts) and TG18 grading score (duration >72 h: 1 pt, image criteria for Grade II AC: 1 pt). Our model, a cutoff score of ≥3, exhibited a significantly elevated area under the curve (AUC) of 0.721 compared to the TG18 grading system alone (AUC 0.609) (p = 0.001). CONCLUSION: Combining preoperative CRP values with TG18 grading criteria can enhance the accuracy of predicting intraoperative difficulty in ELC for AC.

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.

Benefits of laparoscopic liver resection in elderly patients.

BACKGROUND: The indications of laparoscopic liver resection (LLR) have expanded to high-risk patients, such as elderly people. However, to date, little evidence has been established of the safety and feasibility of LLR in elderly patients. The short-term outcomes of LLR in elderly patients as compared to non-elderly patients were investigated. METHODS: Data of a total of 297 patients who underwent LLR were reviewed. Among these 297 patients, 181 patients were < 75 years age (non-elderly) and 116 patients were ≥ 75 years age (elderly), and the surgical outcomes were compared between the groups. In addition, we evaluated the risk factors for postoperative morbidity (Clavien-Dindo grade ≥ IIIa) utilizing the preoperative, operative, and postoperative variables RESULTS: The preoperative liver/renal function, frequency of anti-thrombotic drug use, number of comorbidities, and American Society of Anesthesiologists-physical status classification were more unfavorable in elderly patients than in non-elderly patients. No significant inter-group differences were observed in the operation time, blood loss, conversion rate, postoperative morbidity, or 30-day mortality. The 3-year overall survival rate was comparable between the two groups. Multivariate analysis identified anti-thrombotic drug use, operation time > 7 h, and peak serum total bilirubin > 2 mg/dl within postoperative day 3 as independent risk factors for Clavien-Dindo ≥ IIIa postoperative morbidity (P = 0.016, P < 0.001, and P = 0.001, respectively). CONCLUSIONS: LLR in elderly patients may provide comparable short-term outcomes to those in non-elderly patients.

Early laparoscopic cholecystectomy for acute cholecystitis following the Tokyo Guidelines 2018: a prospective single-center study of 201 consecutive cases.

BACKGROUND: Early laparoscopic cholecystectomy (ELC) for acute cholecystitis (AC) poses multiple challenges. The Tokyo Guidelines 2018 (TG18) eliminated the time limit (< 72 h) and expanded the surgical indication to severe AC. This study aimed to evaluate the clinical outcomes of ELC for AC following the TG18 in a single high-volume center. METHODS: From 2019 to 2021, we managed all AC patients with a TG18 flowchart and prospectively enrolled those who underwent ELC within 7 days of symptom onset. The primary outcome was overall morbidity, with a comparison between mild (Grade I) and moderate/severe (Grade II/III) AC. RESULTS: During the study period, 201 patients underwent ELC was for Grade I (56.2%), II (40.3%), and III (3.5%) ACs. Mean age was 69 ± 15.2 years and time to surgery from symptom onset was 0 (12.9%), 1-3 (66.7%), and 4-7 days (20.4%). Mean operative time and blood loss were 118.9 ± 42.7 min and 57.8 ± 99.4 mL, respectively. The critical view of safety (CVS) was achieved in 76.1% of patients, and bailout procedures were performed in 21.4%. There were no open conversions or bile duct injuries. Major morbidities (Clavien-Dindo classification ≥ IIIa) were observed in 5.5% of cases and mortality in 0.5%. Comparing Grades II/III to Grade I, operative time was longer (112.3 vs. 127.3 min, p = 0.014), blood loss was higher (40.3 vs. 80.1 mL, p = 0.005), the CVS rate was lower (83.2 vs. 67.0%, p = 0.012), and the major morbidity rate was higher (1.8 vs. 10.2%, p = 0.012). In the subgroup analysis of Grade II/III, there were no significant differences in major morbidities (p = 0.288) between the two groups (0-3 vs. 4-7 days). CONCLUSION: ELC for AC following TG18 is feasible with low morbidity rates. However, ELC for Grade II/III ACs remains challenging, and surgeons must carefully assess intraoperative difficulties and surgical risks before proceeding.

Robotic versus laparoscopic liver resections for hepatolithiasis: an international multicenter propensity score matched analysis.

INTRODUCTION: Minimally invasive liver resection (MILR) is widely recognized as a safe and beneficial procedure in the treatment of both malignant and benign liver diseases. Hepatolithiasis has traditionally been reported to be endemic only in East Asia, but has seen a worldwide uptrend in recent decades with increasingly frequent and invasive endoscopic instrumentation of the biliary tract for a myriad of conditions. To date, there has been a woeful lack of high-quality evidence comparing the laparoscopic (LLR) and robotic (RLR) approaches to treatment hepatolithiasis. METHODS: This is an international multicenter retrospective analysis of 273 patients who underwent RLR or LRR for hepatolithiasis at 33 centers in 2003-2020. The baseline clinicopathological characteristics and perioperative outcomes of these patients were assessed. To minimize selection bias, 1:1 (48 and 48 cases of RLR and LLR, respectively) and 1:2 (37 and 74 cases of RLR and LLR, respectively) propensity score matching (PSM) was performed. RESULTS: In the unmatched cohort, 63 (23.1%) patients underwent RLR, and 210 (76.9%) patients underwent LLR. Patient clinicopathological characteristics were comparable between the groups after PSM. After 1:1 and 1:2 PSM, RLR was associated with less blood loss (p = 0.003 in 1:2 PSM; p = 0.005 in 1:1 PSM), less patients with blood loss greater than 300 ml (p = 0.024 in 1:2 PSM; p = 0.027 in 1:1 PSM), and lower conversion rate to open surgery (p = 0.003 in 1:2 PSM; p < 0.001 in 1:1 PSM). There was no significant difference between RLR and LLR in use of the Pringle maneuver, median Pringle maneuver duration, 30-day readmission rate, postoperative morbidity, major morbidity, reoperation, and mortality. CONCLUSION: Both RLR and LLR were safe and feasible for hepatolithiasis. RLR was associated with significantly less blood loss and lower open conversion rate.

Educational Scoring System in Laparoscopic Cholecystectomy: Is It the Right Time to Standardize?

Background and Objectives: Laparoscopic cholecystectomy (LC) is one of the most performed surgeries worldwide. Procedure difficulty and patient outcomes depend on several factors which are not considered in the current literature, including the learning curve, generating confusing and subjective results. This study aims to create a scoring system to calculate the learning curve of LC based on hepatobiliopancreatic (HPB) experts' opinions during an educational course. Materials and Methods: A questionnaire was submitted to the panel of experts attending the HPB course at Research Institute against Digestive Cancer-IRCAD (Strasbourg, France) from 27-29 October 2022. Experts scored the proposed variables according to their degree of importance in the learning curve using a Likert scale from 1 (not useful) to 5 (very useful). Variables were included in the composite scoring system only if more than 75% of experts ranked its relevance in the learning curve assessment ≥4. A positive or negative value was assigned to each variable based on its effect on the learning curve. Results: Fifteen experts from six different countries attended the IRCAD HPB course and filled out the questionnaire. Ten variables were finally included in the learning curve scoring system (i.e., patient body weight/BMI, patient previous open surgery, emergency setting, increased inflammatory levels, presence of anatomical bile duct variation(s), and appropriate critical view of safety (CVS) identification), which were all assigned positive values. Minor or major intraoperative injuries to the biliary tract, development of postoperative complications related to biliary injuries, and mortality were assigned negative values. Conclusions: This is the first scoring system on the learning curve of LC based on variables selected through the experts' opinions. Although the score needs to be validated through future studies, it could be a useful tool to assess its efficacy within educational programs and surgical courses.

A goal-directed therapy protocol for preventing acute kidney injury after laparoscopic liver resection: a retrospective observational cohort study.

PURPOSE: Postoperative acute kidney injury (AKI) remains a serious complication of liver resection with restrictive fluid therapy. However, unlike open hepatectomy, laparoscopic liver resection (LLR) does not have established anesthesia management strategies. We compared our goal-directed therapy (GDT) protocol for LLR with/without carperitide and the conventional restrictive method regarding AKI prevention. METHODS: The GDT thresholds in this retrospective observational cohort study were as follows: stroke volume variation, ≤ 15%; pulse pressure variation, ≤ 13%; oxygen delivery index, ≥ 600 mL/min/m2; and mean arterial pressure (MAP), ≥ 55 mmHg. If the thresholds were not achieved, a 250 mL infusion fluid bolus was administered. The MAP target was changed to > 65 mmHg if the urine output was < 0.3 mL/kg/h. Postoperative AKI within 48 h and perioperative outcomes within 90 days were analyzed. RESULTS: Forty-seven propensity score-matched pairs from 127 patients were investigated. We adjusted for AKI risk factors and surgical difficulty; 46.8% of the GDT group received carperitide. The GDT group had a lower postoperative AKI rate (10.6% vs. 27.7%, P = 0.04) and shorter overall (P = 0.04) and postoperative (P < 0.01) hospital stays than the conventional group. Furthermore, the GDT group received more intraoperative fluid (P = 0.001) and phenylephrine (P = 0.02), without significant increases in blood loss and transfusion volume, than the conventional group. CONCLUSIONS: GDT reduced the AKI rates post-LLR.

Parenchymal Sparing Anatomical Liver Resections With Full Laparoscopic Approach: Description of Technique and Short-term Results.

OBJECTIVE: The aim of this study was to describe laparoscopic anatomical parenchymal sparing liver resections for hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) and report the short-term outcomes. BACKGROUND: Anatomical resections (ARs) have better oncological outcomes compared to partial resections in patients with HCC, and some suggest should be performed also for CRLM as micrometastasis occurs through the intrahepatic structures. Furthermore, remnant liver ischemia after partial resections has been associated with worse oncological outcomes. Few experiences on laparoscopic anatomical resections have been reported and no data on limited AR exist. METHODS: We performed a retrospective analysis of 86 patients undergoing full laparoscopic anatomical parenchymal sparing resections with preoperative surgical simulation and standardized procedures. RESULTS: A total of 55 patients had HCC, whereas 31 had CRLM with a median of 1 lesion and a size of 30 mm. During preoperative three-dimensional (3D) simulation, a median resection volume of 120 mL was planned. Sixteen anatomical subsegmentectomies, 56 segmentectomies, and 14 sectionectomies were performed. Concordance between preoperative 3D simulation and intraoperative resection was 98.7%. Two patients were converted, and 7 patients experienced complications. Subsegmentectomies had comparable blood loss (166 mL, P = 0.59), but longer operative time (426 min, P = 0.01) than segmentectomies (blood loss 222 mL; operative time 355 min) and sectionectomies (blood loss 120 mL; operative time 295 min). R0 resection and margin width remained comparable among groups. CONCLUSIONS: A precise preoperative planning and a standardized surgical technique allow to pursue the oncological quality of AR enhancing the safety of the parenchyma sparing principle, reducing surgical stress through a laparoscopic approach.

Pure Laparoscopic Right Hepatectomy for Hepatocellular Carcinoma with Bile Duct Tumor Thrombus (with Video).

BACKGROUND: Laparoscopic liver resection has been increasingly utilized due to its less invasiveness approach compared with open surgery,1-3 but often creates challenges. Hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) portends a poorer prognosis and often precludes patients from potential liver resection.4-6 We herein report a case of laparoscopic hepatectomy and thrombectomy in a patient with HCC and BDTT. METHODS: CT, ERCP, and POCS showed a 40-mm tumor located in the right lobe with BDTT. A five 12-mm trocar was inserted at the umbilicus for laparoscope, the epigastrium, both sides of the hypochondrium, and right lateral region. Moreover, a 5-mm trocar was inserted at left hypochondrium. After cholecystectomy, hepatoduodenal ligament was encircled using the tourniquet through 5-mm trocar site. The right portal vein was transected by stapler following transection of the right hepatic artery. After ICG staining (0.5 mg/body i.v.),7 hepatic parenchymal transection was performed using clamp-crashing technique. Moreover, CUSA also was used near Glissonian sheath. BDTT was removed from the right BD. Moreover, the cholangioscopy confirmed no BDTT remnants. The resection stump was then sutured. Finally, the right hepatic vein was divided with a stapler. A drainage tube was placed in the right subphrenic space. Operation time was 496 min, and blood loss was 91 ml. The patient was discharged without complications on postoperative day 11. Pathological diagnosis showed moderately differentiated HCC, tumor size 40 × 45 mm with negative surgical margins. CONCLUSIONS: Pure laparoscopic resection for HCC with BDTT is a radical, yet feasible procedure.

Remarkable Effects of External Magnetic Field on Circularly Polarized Luminescence of EuIII (hfa)3 with Phosphine Chirality.

Herein, magnetic circularly polarized luminescence (CPL) (MCPL) spectroscopy was conducted to analyze an EuIII (hfa)3 complex with three chiral PIII -ligands. Resultantly, (R)-chirality luminophores with S-up orientation and (S)-chirality luminophores with N-up orientation were observed to possess symmetrical mirror image spectra, i. e., they were enantiomers. Similarly, the (R)-chirality luminophores with N-up orientation and the (S)-chirality luminophores with S-up orientation were also enantiomers. Contrarily, (R)-S-up and (S)-S-up were diastereomers and did not possess a mirror-image relationship. Likewise, (R)-N-up and (S)-N-up were diastereomers. The J-dependency of gMCPL and gCPL datasets suggested that the N-up/S-up external magnetic field, with the aid of chiral PIII -ligands, increased the gMCPL values by two- to sixteen-fold and modulated the gMCPL signs at J=1-4. Additionally, the origins of the nonideal mirror-symmetric CPL and MCPL spectral characteristics of EuIII (hfa)3 with three chiral PIII -ligands were discussed in terms of parity (space-inversion, P)-symmetry, time-reversal (T)-symmetry, and PT-symmetry laws.

[Gallbladder Metastasis from Renal Cell Carcinoma Four Years after Nephrectomy-A Case Report].

An 80-year-old man who had undergone nephrectomy for renal cell carcinoma(RCC)4 years before presentation was admitted to our department for further investigation of the gallbladder tumor. The patient was diagnosed with early gallbladder carcinoma based on CT and MRI findings and treated with laparoscopic cholecystectomy. The intraoperative frozen section revealed that the identified tumor was clear cell carcinoma. Finally, morphological similarity with a previous specimen of RCC and immunostaining resulted in the diagnosis of gallbladder metastasis from RCC. Therefore, it is important to consider metastatic carcinoma of the gallbladder in the differential diagnosis of gallbladder tumors for patients with a history of renal cell carcinoma.

Latest Findings on Minimally Invasive Anatomical Liver Resection.

Minimally invasive liver resection (MILR) is being widely utilized owing to recent advancements in laparoscopic and robot-assisted surgery. There are two main types of liver resection: anatomical (minimally invasive anatomical liver resection (MIALR)) and nonanatomical. MIALR is defined as a minimally invasive liver resection along the respective portal territory. Optimization of the safety and precision of MIALR is the next challenge for hepatobiliary surgeons, and intraoperative indocyanine green (ICG) staining is considered to be of considerable importance in this field. In this article, we present the latest findings on MIALR and laparoscopic anatomical liver resection using ICG at our hospital.

How Much Is Enough? A Surgical Perspective on Imaging Modalities to Estimate Function and Volume of the Future Liver Remnant before Hepatic Resection.

Liver resection is the first curative option for most hepatic primary and secondary malignancies. However, post-hepatectomy liver failure (PHLF) still represents a non-negligible postoperative complication, embodying the most frequent cause of hepatic-related mortality. In the absence of a specific treatment, the most effective way to deal with PHLF is its prevention through a careful preoperative assessment of future liver remnant (FLR) volume and function. Apart from the clinical score and classical criteria to define the safe limit of resectability, new imaging modalities have shown their ability to assist surgeons in planning the best operative strategy with a precise estimation of the FLR amount. New technologies leading to liver and tumor 3D reconstruction may guide the surgeon along the best resection planes combining the least liver parenchymal sacrifice with oncological appropriateness. Integration with imaging modalities, such as hepatobiliary scintigraphy, capable of estimating total and regional liver function, may bring about a decrease in postoperative complications. Magnetic resonance imaging with hepatobiliary contrast seems to be predominant since it simultaneously integrates hepatic function and volume information along with a precise characterization of the target malignancy.

Partial Hepatic Vein Occlusion and Venous Congestion in Liver Exploration Using a Hyperspectral Camera: A Proposal for Monitoring Intraoperative Liver Perfusion.

INTRODUCTION: The changes occurring in the liver in cases of outflow deprivation have rarely been investigated, and no measurements of this phenomenon are available. This investigation explored outflow occlusion in a pig model using a hyperspectral camera. METHODS: Six pigs were enrolled. The right hepatic vein was clamped for 30 min. The oxygen saturation (StO2%), deoxygenated hemoglobin level (de-Hb), near-infrared perfusion (NIR), and total hemoglobin index (THI) were investigated at different time points in four perfused lobes using a hyperspectral camera measuring light absorbance between 500 nm and 995 nm. Differences among lobes at different time points were estimated by mixed-effect linear regression. RESULTS: StO2% decreased over time in the right lateral lobe (RLL, totally occluded) when compared to the left lateral (LLL, outflow preserved) and the right medial (RML, partially occluded) lobes (p < 0.05). De-Hb significantly increased after clamping in RLL when compared to RML and LLL (p < 0.05). RML was further analyzed considering the right portion (totally occluded) and the left portion of the lobe (with an autonomous draining vein). StO2% decreased and de-Hb increased more smoothly when compared to the totally occluded RLL (p < 0.05). CONCLUSIONS: The variations of StO2% and deoxy-Hb could be considered good markers of venous liver congestion.

Sub-classification of laparoscopic left hepatectomy based on hierarchic interaction of tumor location and size with perioperative outcomes.

BACKGROUND: The aim of this multicentric study was to investigate the impact of tumor location and size on the difficulty of Laparoscopic-Left Hepatectomy (L-LH). METHODS: Patients who underwent L-LH performed across 46 centers from 2004 to 2020 were analyzed. Of 1236 L-LH, 770 patients met the study criteria. Baseline clinical and surgical characteristics with a potential impact on LLR were included in a multi-label conditional interference tree. Tumor size cut-off was algorithmically determined. RESULTS: Patients were stratified into 3 groups based on tumor location and dimension: 457 in antero-lateral location (Group 1), 144 in postero-superior segment (4a) with tumor size ≤40 mm (Group 2), and 169 in postero-superior segment (4a) with tumor size >40 mm (Group 3). Patients in the Group 3 had higher conversion rate (7.0% vs. 7.6% vs. 13.0%, p-value .048), longer operating time (median, 240 min vs. 285 min vs. 286 min, p-value <.001), greater blood loss (median, 150 mL vs. 200 mL vs. 250 mL, p-value <.001) and higher intraoperative blood transfusion rate (5.7% vs. 5.6% vs. 11.3%, p-value .039). Pringle's maneuver was also utilized more frequently in Group 3 (66.7%), compared to Group 1 (53.2%) and Group 2 (51.8%) (p = .006). There were no significant differences in postoperative stay, major morbidity, and mortality between the three groups. CONCLUSION: L-LH for tumors that are >40 mm in diameter and located in PS Segment 4a are associated with the highest degree of technical difficulty. However, post-operative outcomes were not different from L-LH of smaller tumors located in PS segments, or tumors located in the antero-lateral segments.