Association between tumor morphology and efficacy of atezolizumab plus bevacizumab for advanced hepatocellular carcinoma.

AIM: The IMbrave150 trial revealed that atezolizumab plus bevacizumab (AtezoBv) showed a higher objective response rate (ORR) in patients with advanced hepatocellular carcinoma (HCC). Although conversion therapy after AtezoBv has been recently reported, markers predictive of its efficacy, particularly radiological imaging markers, have not yet been identified. The present study focused on tumor morphological appearance on radiological imaging and evaluated whether it could be associated with AtezoBv efficacy. METHODS: Ninety-five intrahepatic lesions in 74 patients who were given AtezoBv for advanced HCC were recruited for evaluation. The lesions were divided into two groups, simple nodular (SN group) and non-simple nodular (non-SN group), based on the gross morphology on pretreatment imaging, and retrospectively evaluated for treatment response and other relevant clinical outcomes. RESULTS: Assessing the size of individual tumors after treatment, waterfall plots showed that tumor shrinkage in the non-SN group including 56 lesions was higher than that in the SN group comprising 39 lesions. The ORR was significantly higher in the non-SN group (39.3% vs. 15.4%, p = 0.012). Additionally, the median time to nodular progression was longer in the non-SN group (21.0 months vs. 8.1 months, p = 0.119) compared to the SN group. Six patients with non-SN lesions underwent sequential local therapy. CONCLUSIONS: Atezolizumab plus bevacizumab may show increased therapeutic efficacy in patients with tumors with a higher potential for aggressive oncological behavior, such as non-SN lesions. Treatment strategies focusing on conversion therapy may be crucial in patients with non-SN lesions.

Optimal cutoff values of drain amylase for predicting pancreatic fistula are different between open and laparoscopic distal pancreatectomy.

BACKGROUND: Drainage fluid amylase (DFA) is useful for predicting clinically relevant postoperative pancreatic fistula (CR-POPF) after distal pancreatectomy (DP). However, difference in optimal cutoff value of DFA for predicting CR-POPF between open DP (ODP) and laparoscopic DP (LDP) has not been investigated. This study aimed to identify the optimal cutoff values of DFA for predicting CR-POPF after ODP and LDP. METHODS: Data for 294 patients (ODP, n = 127; LDP, n = 167) undergoing DP at Kobe University Hospital between 2010 and 2021 were reviewed. Propensity score matching was performed to minimize treatment selection bias. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff values of DFA for predicting CR-POPF for ODP and LDP. Logistic regression analysis for CR-POPF was performed to investigate the diagnostic value of DFA on postoperative day (POD) three with identified cutoff value. RESULTS: In the matched cohort, CR-POPF rates were 24.7% and 7.9% after ODP and LDP, respectively. DFA on POD one was significantly lower after ODP than after LDP (2263 U/L vs 4243 U/L, p < 0.001), while the difference was not significant on POD three (543 U/L vs 1221 U/L, p = 0.171). ROC analysis revealed that the optimal cutoff value of DFA on POD one and three for predicting CR-POPF were different between ODP and LDP (ODP, 3697 U/L on POD one, 1114 U/L on POD three; LDP, 10564 U/L on POD one, 6020 U/L on POD three). Multivariate analysis showed that DFA on POD three with identified cutoff value was the independent predictor for CR-POPF both for ODP and LDP. CONCLUSIONS: DFA on POD three is an independent predictor for CR-POPF after both ODP and LDP. However, the optimal cutoff value for it is significantly higher after LDP than after ODP. Optimal threshold of DFA for drain removal may be different between ODP and LDP.

A Novel Method Using Gadolinium-Ethoxybenzyl Diethylenetriamine Pentaacetate Acid-Enhanced Magnetic Resonance Imaging for Predicting Post-Hepatectomy Liver Failure in Hepatocellular Carcinoma Patients with a Major Portal Vein Tumor Thrombus.

INTRODUCTION: The usefulness of gadolinium-ethoxybenzyl diethylenetriamine pentaacetate acid-enhanced magnetic resonance imaging (EOB-MRI) in assessing the functional future remnant liver volume (fFRLV) to predict post-hepatectomy liver failure (PHLF) has been previously reported. Herein, we evaluated the efficacy of this technique in patients with hepatocellular carcinoma (HCC) with a major portal vein tumor thrombus (PVTT). METHODS: This study included 21 patients with PVTT in the ipsilateral first-order branch (Vp3) and 30 patients with PVTT in the main trunk/contralateral branch (Vp4). To evaluate fFRLV, the signal intensity (SI) of the remnant liver was determined on T1-weighted images, using both conventional and newly developed methods. The fFRLV was calculated using the SI of the remnant liver and muscle, remnant liver volume, and body surface area. Preoperative factors predicting PHLF (≥grade B) in HCC patients with Vp3/4 PVTT were evaluated. RESULTS: In the Vp3 group, we found fFRLV area under the receiver-operating characteristic curves (AUCs) above 0.70 (AUC = 0.875, 0.750) using EOB-MRI results calculated using either the plot or whole method. None of the parameters in the Vp4 group had an AUC greater than 0.70. CONCLUSION: The fFRLV calculated by EOB-MRI using the whole method can be as useful as the conventional method in predicting PHLF (≥grade B) for HCC patients with Vp3 PVTT.

Liver ischemia-reperfusion injury: From trigger loading to shot firing.

An ischemia-reperfusion injury (IRI) results from a prolonged ischemic insult followed by the restoration of blood perfusion, being a common cause of morbidity and mortality, especially in liver transplantation. At the maximum of the potential damage, IRI is characterized by 2 main phases. The first is the ischemic phase, where the hypoxia and vascular stasis induces cell damage and the accumulation of damage-associated molecular patterns and cytokines. The second is the reperfusion phase, where the local sterile inflammatory response driven by innate immunity leads to a massive cell death and impaired liver functionality. The ischemic time becomes crucial in patients with underlying pathophysiological conditions. It is possible to compare this process to a shooting gun, where the loading trigger is the ischemia period and the firing shot is the reperfusion phase. In this optic, this article aims at reviewing the main ischemic events following the phases of the surgical timeline, considering the consequent reperfusion damage.

Laparoscopic Medial-to-Lateral Approach for the Resection of Hepatocellular Carcinoma Located at the Spiegel Lobe of the Liver.

BACKGROUND: Laparoscopic caudate lobe resection is a challenging procedure. Several researchers have reported the safety of laparoscopic liver resections;1.Transl Gastroenterol Hepatol. 1:56;2.Asian J Endosc Surg. 12:232-236;3.Ann Surg Oncol. 26:2980; however, a standardized procedure has not yet been established. Herein, we present a video showing laparoscopic Spiegel lobectomy in a patient with 6-cm hepatocellular carcinoma (HCC) using a novel approach. PATIENT AND METHODS: A 63-year-old man with a caudate lobe HCC was referred to our hospital. Computed tomography showed a 5 × 6 cm2 HCC located in the Spiegel lobe, which profoundly displaced the inferior vena cava (IVC) to the lower right side, and mobilization of the Spiegel lobe was considered difficult. To perform the dissection between the Siegel lobe and IVC safely, we performed parenchymal transection along the ventral side of the IVC initially. The Spiegel lobe was then dislocated to the left side of the IVC. We dissected the left lateral side of the IVC, including the proper hepatic vein draining the caudate lobe and the left IVC ligament with a safe operative field, and successfully removed the Spiegel lobe with large HCC. RESULTS: The operation time was 383 min. The blood loss was 10 mL. The patient was discharged on the seventh postoperative day without any complications. Histopathological examination revealed well-differentiated HCC with a negative surgical margin. CONCLUSIONS: Laparoscopic medial-to-lateral approach with initial parenchymal transection at the medial side of the Spiegel lobe followed by dissection of the left lateral side of the IVC is considered as a safe and effective procedure for large tumors in the Spiegel lobe.

The Usefulness of Total Tumor Volume as a Prognostic Factor and in Selecting the Optimal Treatment Strategy of Chemotherapeutic Intervention in Patients with Colorectal Liver Metastases.

BACKGROUND: Few reports have discussed the association between total tumor volume (TTV) and prognosis in patients with colorectal liver metastases (CRLM). The present study aimed to evaluate the usefulness of TTV for predicting recurrence-free survival and overall survival (OS) in patients receiving initial hepatic resection or chemotherapy, and to investigate the value of TTV as an indicator for optimal treatment selection for patients with CRLM. PATIENTS AND METHODS: This retrospective cohort study included patients with CRLM who underwent hepatic resection (n = 93) or chemotherapy (n = 78) at the Kobe University Hospital. TTV was measured using 3D construction software and computed tomography images. RESULTS: A TTV of 100 cm3 has been previously reported as a significant cut-off value for predicting OS of CRLM patients receiving initial hepatic resection. For patients receiving hepatic resection, the OS for those with a TTV ≥ 100 cm3 was significantly reduced compared with those with a TTV < 100 cm3. For patients receiving initial chemotherapy, there were no significant differences between the groups divided according to TTV cut-offs. Regarding OS of patients with TTV ≥ 100 cm3, there was no significant difference between hepatic resection and chemotherapy (p = 0.160). CONCLUSIONS: TTV can be a predictive factor of OS for hepatic resection, unlike for initial chemotherapy treatment. The lack of significant difference in OS for CRLM patients with TTV ≥ 100 cm3, regardless of initial treatment, suggests that chemotherapeutic intervention preceding hepatic resection may be indicated for such patients.

Risk Factors for Recurrence of Cholangitis After Pancreaticoduodenectomy and Comparison of Stents in Hepaticojejunostomy.

BACKGROUND: Postoperative cholangitis is a common complication of pancreaticoduodenectomy. Frequent cholangitis impairs patients' quality of life after pancreaticoduodenectomy. However, the risk factors for recurrence of cholangitis remain unclear. Hence, this retrospective study aimed to identify risk factors for recurrence of cholangitis after pancreaticoduodenectomy. METHODS: The medical records of patients who underwent pancreaticoduodenectomy between 2015 and 2019 in our institution were retrospectively reviewed. At least two episodes of cholangitis a year after pancreaticoduodenectomy were defined as 'recurrence of cholangitis' in the present study. Univariate and multivariate analyses were performed. RESULTS: The recurrence of cholangitis occurred in 40 of 207 patients (19.3%). Multivariate analysis revealed that internal stent (external, RR: 2.16, P = 0.026; none, RR: 4.76, P = 0.011), firm pancreas (RR: 2.61, P = 0.021), constipation (RR: 3.49, P = 0.008), and postoperative total bilirubin>1.7 mg/dL (RR: 2.94, P = 0.006) were risk factors of recurrence of cholangitis. Among patients with internal stents (n = 54), those with remnant stents beyond 5 months had more frequent recurrence of cholangitis (≥5 months, 75%; <5 months, 30%). CONCLUSIONS: Internal stents, firm pancreas, constipation, and postoperative high bilirubin levels are risk factors for cholangitis recurrence after pancreaticoduodenectomy. In addition, the long-term implantation of internal stents may trigger cholangitis recurrence.

Transarterial chemoembolization for liver metastases of a pancreatic neuroendocrine neoplasm: a single-center experience.

Transarterial chemoembolization (TACE) is performed for pancreatic neuroendocrine tumor (PanNEN) liver metastases; however, the safety and efficacy of TACE procedures, especially for patients who have undergone previous pancreatic surgery, have not been established. We reviewed 48 TACE procedures (1-6 procedures/patient) performed on 11 patients with PanNEN liver metastases, including 16 TACE procedures (4-6 procedures/patient) for 3 patients with a history of biliary-enteric anastomosis. The overall tumor objective response rate was 94%. The incidence of Clavien‒Dindo grade ≥ 2 complications was 1/16 (6%) and 1/32 (3%), and the median time to untreatable progression was 31 (14-41) and 27 (2-60) months among patients with and without a history of biliary-enteric anastomosis, respectively. Although validation is needed in future studies, our experiences have shown that TACE treatment is a viable treatment option for PanNEN liver metastases, even after biliary-enteric anastomosis with experienced teams and careful patient follow-up.

Impact of GLIM criteria-based malnutrition diagnosis on outcomes following liver resection for hepatocellular carcinoma.

BACKGROUND: The Global Leadership Initiative on Malnutrition (GLIM), comprising several of the major global clinical nutrition societies, suggested the world's first criteria for diagnosis of the severity of malnutrition. However, the impact of the resulting diagnosis on patient outcomes for those with hepatocellular carcinoma (HCC) following liver resection (LR) has not been investigated. METHODS: A retrospective analysis of 293 patients with HCC who underwent LR between January 2011 and December 2018 was performed. We compared overall survival (OS) and recurrence-free survival (RFS) and evaluated prognostic factors after LR using Cox proportional hazards regression models. RESULTS: Preoperative patient nutritional status, n (%), was classified as follows: normal, 130 (44%), moderate malnutrition, 116 (40%), and severe malnutrition, 47 (16%). The median OS (129 vs. 43 months, p < 0.001) and median RFS (54 vs. 20 months, p = 0.001) were significantly greater in the normal group than in the severe malnutrition group. Multivariate analysis showed that severe malnutrition was a significant risk factor for OS (p = 0.006) and RFS (p = 0.010) after initial LR. CONCLUSION: Severe malnutrition, as diagnosed by the GLIM criteria, is a significant prognostic factor for survival and recurrence in patients with HCC after LR.

[A Case of Ampullary Carcinoma with Celiac Axis Stenosis That Underwent Pancreaticoduodenectomy and Arterial Reconstruction].

A 72-year-old male patient presented with obstructive jaundice and was diagnosed with ampullary carcinoma. Contrast- enhanced computed tomography(CT)showed stenosis of the common hepatic artery and dilatation of the pancreaticoduodenal arcade(PDA)due to celiac axis stenosis(CAS)at the origin, suggesting that hepatic artery blood flow was supplied from the superior mesenteric artery via the PDA. Since calcification of the arterial wall was observed at the origin of the celiac artery(CA), the cause of the CAS was diagnosed as atherosclerotic. An intraoperative gastroduodenal artery(GDA) clamp test showed no obvious decrease in hepatic arterial blood flow. However, because of concerns about the postoperative patency of the CA, an inferior pancreaticoduodenal artery-GDA bypass using the left great saphenous vein and subtotal stomach-preserving pancreaticoduodenectomy were performed. The postoperative course was uneventful. When pancreaticoduodenectomy is performed in patients with atherosclerotic CAS, this arterial reconstruction method can be considered as an option.

Artificial Intelligence for Surgical Safety: Automatic Assessment of the Critical View of Safety in Laparoscopic Cholecystectomy Using Deep Learning.

OBJECTIVE: To develop a deep learning model to automatically segment hepatocystic anatomy and assess the criteria defining the critical view of safety (CVS) in laparoscopic cholecystectomy (LC). BACKGROUND: Poor implementation and subjective interpretation of CVS contributes to the stable rates of bile duct injuries in LC. As CVS is assessed visually, this task can be automated by using computer vision, an area of artificial intelligence aimed at interpreting images. METHODS: Still images from LC videos were annotated with CVS criteria and hepatocystic anatomy segmentation. A deep neural network comprising a segmentation model to highlight hepatocystic anatomy and a classification model to predict CVS criteria achievement was trained and tested using 5-fold cross validation. Intersection over union, average precision, and balanced accuracy were computed to evaluate the model performance versus the annotated ground truth. RESULTS: A total of 2854 images from 201 LC videos were annotated and 402 images were further segmented. Mean intersection over union for segmentation was 66.6%. The model assessed the achievement of CVS criteria with a mean average precision and balanced accuracy of 71.9% and 71.4%, respectively. CONCLUSIONS: Deep learning algorithms can be trained to reliably segment hepatocystic anatomy and assess CVS criteria in still laparoscopic images. Surgical-technical partnerships should be encouraged to develop and evaluate deep learning models to improve surgical safety.

Standardization of laparoscopic anatomic liver resection of segment 2 by the Glissonean approach.

BACKGROUND: Anatomic liver resection (ALR) has been established to eliminate the tumor-bearing hepatic region with preservation of the remnant liver volume for liver malignancies. Recently, laparoscopic ALR has been widely applied; however, there are few reports on laparoscopic segmentectomy 2. This study aimed to present the standardization of laparoscopic segmentectomy 2 with surgical outcomes. METHODS: This study included seven patients who underwent pure laparoscopic segmentectomy 2 by the Glissonean approach from January 2020 to December 2021. Four of them had hepatocellular carcinoma, two had colorectal liver metastasis, and one had hepatic angiomyolipoma, which was preoperatively diagnosed with hepatocellular carcinoma. In all patients, preoperative three-dimensional (3D) simulation images from dynamic CT were reconstructed using a 3D workstation. The layer between the hepatic parenchyma and the Glissonean pedicle of segment 2 (G2) was dissected to encircle the root of G2. After clamping or ligation of the G2, 2.5 mg of indocyanine green was injected intravenously to identify the boundaries between segments 2 and 3 with a negative staining method under near-infrared light. Parenchymal transection was performed from the caudal side to the cranial side according to the demarcation on the liver surface, and the left hepatic vein was exposed on the cut surface if possible. RESULTS: The mean operative time for all patients was 281 min. The mean blood loss was 37 mL, and no transfusion was necessary. Estimated liver resection volumes significantly correlated with actual liver resection volumes (r = 0.61, P = 0.035). After the operation, one patient presented with asymptomatic deep venous and pulmonary thrombosis, which was treated with anticoagulant therapy. The mean length of hospital stay was 8.9 days. CONCLUSION: Laparoscopic segmentectomy 2 by the Glissonean approach is a feasible and safe procedure with the preservation of the nontumor-bearing segment 3 for liver tumors in segment 2.

Prognostic Impact of Inflammation-Based Scores for Extrahepatic Cholangiocarcinoma.

INTRODUCTION: Although the relationship between systemic inflammatory responses and prognosis has been known in various cancers, it remains unclear which scores are most valuable for determining the prognosis of extrahepatic cholangiocarcinoma. We aimed to verify the usefulness of various inflammation-based scores as prognostic factors in patients with resected extrahepatic cholangiocarcinoma. METHODS: We analyzed consecutive patients undergoing surgical resection for extrahepatic cholangiocarcinoma at our institution between January 2000 and December 2019. The usefulness of the following inflammation-based scores as prognostic factor was investigated: glasgow prognostic score (GPS), modified GPS, neutrophil-to-lymphocyte ratio, platelet to lymphocyte ratio, lymphocyte-to-monocyte ratio, prognostic nutrition index, C-reactive protein to albumin ratio (CAR), controlling nutritional status (CONUT), and prognostic index. RESULTS: A total of 169 patients were enrolled in this study. Of the nine scores, CAR and CONUT indicated prognostic value. Furthermore, multivariate analysis for overall survival revealed that high CAR (>0.23) was an independent prognostic factor (hazard ratio: 1.816, 95% confidence interval: 1.135-2.906, p = 0.0129), along with lymph node metastasis and curability. There was no difference in tumor staging and short-term outcomes between the low CAR (≤0.23) and high CAR groups. CONCLUSIONS: CAR was the most valuable prognostic score in patients with resected extrahepatic cholangiocarcinoma.

A Computer Vision Platform to Automatically Locate Critical Events in Surgical Videos: Documenting Safety in Laparoscopic Cholecystectomy.

OBJECTIVE: The aim of this study was to develop a computer vision platform to automatically locate critical events in surgical videos and provide short video clips documenting the critical view of safety (CVS) in laparoscopic cholecystectomy (LC). BACKGROUND: Intraoperative events are typically documented through operator-dictated reports that do not always translate the operative reality. Surgical videos provide complete information on surgical procedures, but the burden associated with storing and manually analyzing full-length videos has so far limited their effective use. METHODS: A computer vision platform named EndoDigest was developed and used to analyze LC videos. The mean absolute error (MAE) of the platform in automatically locating the manually annotated time of the cystic duct division in full-length videos was assessed. The relevance of the automatically extracted short video clips was evaluated by calculating the percentage of video clips in which the CVS was assessable by surgeons. RESULTS: A total of 155 LC videos were analyzed: 55 of these videos were used to develop EndoDigest, whereas the remaining 100 were used to test it. The time of the cystic duct division was automatically located with a MAE of 62.8 ±â€Š130.4 seconds (1.95% of full-length video duration). CVS was assessable in 91% of the 2.5 minutes long video clips automatically extracted from the considered test procedures. CONCLUSIONS: Deep learning models for workflow analysis can be used to reliably locate critical events in surgical videos and document CVS in LC. Further studies are needed to assess the clinical impact of surgical data science solutions for safer laparoscopic cholecystectomy.

Fluoroless intravascular ultrasound image-guided liver navigation in porcine models.

BACKGROUND: An intravascular ultrasound catheter (IVUSc) was developed for intracardiac ultrasound to assess interventions with compelling results. However, intrahepatic vascular exploration was rarely tested and was always associated with X-ray techniques. The aim of this study was to demonstrate the feasibility to navigate through the whole liver using an IVUSc, providing high-quality images and making it unnecessary to use ionizing radiation. METHODS: An ex vivo pig visceral block and an in vivo pig model were used in this study. The IVUS equipment was composed of an US system, and of an 8 French lateral firing IVUSc capable of producing 90-degree sector images in the longitudinal plane. After accessing the intravascular space with the IVUSc into the models, predetermined anatomical landmarks were visualized from the inferior vena cava and hepatic veins and corroborated. RESULTS: IVUS navigation was achieved in both models successfully. The entire navigation protocol took 87 and 48 min respectively, and 100% (21/21) and 96.15% (25/26) of the landmarks were correctly identified with the IVUSc alone in the ex vivo and in vivo models respectively. IVUS allowed to clearly visualize the vasculature beyond third-order branches of the hepatic and portal veins. CONCLUSIONS: A complete IVUS liver navigation is feasible using the IVUSc alone, making it unnecessary to use ionizing radiation. This approach provides high-definition and real-time images of the complex liver structure and offers a great potential for future clinical applications during diagnostic and therapeutic interventions.

Hyperspectral enhanced reality (HYPER) for anatomical liver resection.

BACKGROUND: Clinical evaluation of the demarcation line separating ischemic from non-ischemic liver parenchyma may be challenging. Hyperspectral imaging (HSI) is a noninvasive imaging modality, which combines a camera with a spectroscope and allows quantitative imaging of tissue oxygenation. Our group developed a software to overlay HSI images onto the operative field, obtaining HSI-based enhanced reality (HYPER). The aim of the present study was to evaluate the accuracy of HYPER to identify the demarcation line after a left vascular inflow occlusion during an anatomical left hepatectomy. MATERIALS AND METHODS: In the porcine model (n = 3), the left branches of the hepatic pedicle were ligated. Before and after vascular occlusion, HSI images based on tissue oxygenation (StO2), obtained through the Near-Infrared index (NIR index), were regularly acquired and superimposed onto RGB video. The demarcation line was marked on the liver surface with electrocautery according to HYPER. Local lactates were measured on blood samples from the liver surface in both ischemic and perfused segments using a strip-based device. At the same areas, confocal endomicroscopy was performed. RESULTS: After ligation, HSI demonstrated a significantly lower oxygenation (NIR index) in the left medial lobe (LML) (0.27% ± 0.21) when compared to the right medial lobe (RML) (58.60% ± 12.08; p = 0.0015). Capillary lactates were significantly higher (3.07 mmol/L ± 0.84 vs. 1.33 ± 0.71 mmol/L; p = 0.0356) in the LML versus RML, respectively. Concordantly, confocal videos demonstrated the absence of blood flow in the LML and normal perfusion in the RML. CONCLUSIONS: HYPER has made it possible to correctly identify the demarcation line and quantify surface liver oxygenation. HYPER could be an intraoperative tool to guide perfusion-based demarcation line assessment and segmentation.

Three-dimensional imaging improved the laparoscopic performance of inexperienced operators: a prospective trial.

BACKGROUND: Three-dimensional (3-D) high-definition (HD) stereovision and two-dimensional (2-D) ultra-high-resolution (4K) monitors have recently become available for laparoscopic surgery. The aim of this study was to compare laparoscopic performance between inexperienced participants using 3-D/HD and 2-D/4K monitors and those using conventional 2-D/HD monitors. METHODS: The study enrolled 66 participants with no previous surgical experience or medical training. They were randomly divided into three equal groups, each using a different type of monitor (2-D/HD, 2-D/4K, or 3-D/HD), to perform three phantom tasks using a laparoscopic simulator: Task 1, touching markers on a non-flat surface; Task 2, bimanual peg transfer; and Task 3, passing a straight rod through a loop. Each task was performed three times. The performance scores (operative time, path length of the forceps, and technical errors) were compared for each monitor type and by age group (< 30 vs. > 30 years). RESULTS: For all three tasks, scores using the 3-D monitor were significantly better than those using either 2-D monitor, with no difference between the 2-D/4K and 2-D/HD monitors. Using the 2-D monitors, the performance of Task 3 by the participants > 30 years was worse than that by the younger participants; however, there was no difference between the age groups when using the 3-D monitor. CONCLUSION: Participants with no prior experience using a 3-D monitor showed better laparoscopic performance than those using 2-D monitors, even with 4K resolution. This improvement was more marked in older participants, suggesting a greater loss of depth perception in a 2-D environment.

Formalizing video documentation of the Critical View of Safety in laparoscopic cholecystectomy: a step towards artificial intelligence assistance to improve surgical safety.

BACKGROUND: In laparoscopic cholecystectomy (LC), achievement of the Critical View of Safety (CVS) is commonly advocated to prevent bile duct injuries (BDI). However, BDI rates remain stable, probably due to inconsistent application or a poor understanding of CVS as well as unreliable reporting. Objective video reporting could serve for quality auditing and help generate consistent datasets for deep learning models aimed at intraoperative assistance. In this study, we develop and test a method to report CVS using videos. METHOD: LC videos performed at our institution were retrieved and the video segments starting 60 s prior to the division of cystic structures were edited. Two independent reviewers assessed CVS using an adaptation of the doublet view 6-point scale and a novel binary method in which each criterion is considered either achieved or not. Feasibility to assess CVS in the edited video clips and inter-rater agreements were evaluated. RESULTS: CVS was attempted in 78 out of the 100 LC videos retrieved. CVS was assessable in 100% of the 60-s video clips. After mediation, CVS was achieved in 32/78(41.03%). Kappa scores of inter-rater agreements using the doublet view versus the binary assessment were as follows: 0.54 versus 0.75 for CVS achievement, 0.45 versus 0.62 for the dissection of the hepatocystic triangle, 0.36 versus 0.77 for the exposure of the lower part of the cystic plate, and 0.48 versus 0.79 for the 2 structures connected to the gallbladder. CONCLUSIONS: The present study is the first to formalize a reproducible method for objective video reporting of CVS in LC. Minute-long video clips provide information on CVS and binary assessment yields a higher inter-rater agreement than previously used methods. These results offer an easy-to-implement strategy for objective video reporting of CVS, which could be used for quality auditing, scientific communication, and development of deep learning models for intraoperative guidance.

Demarcation Line Assessment in Anatomical Liver Resection: An Overview.

Anatomical liver resection (ALR) is the preferred oncological approach for the treatment of primary liver malignancies, such as hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The demarcation line (DL) is formed by means of selective vascular occlusion and is used by surgeons to guide ALR. Emerging intraoperative technologies are playing a major role to enhance the surgeon's vision and ensure a precise oncologic surgery. In this article, a brief overview of modalities to assess the DL during ALRs is presented, from the established conventional techniques to future perspectives.

Novel biodegradable magnesium alloy clips compared with titanium clips for hepatectomy in a rat model.

BACKGROUND: The use of surgical metal clips is crucial for ligating vessels in various operations. The currently available metal clips have several drawbacks; they are permanent and interfere with imaging techniques such as computed tomography (CT) or magnetic resonance (MR) imaging and carry the potential risk of endo-clip migration. We recently developed a novel magnesium (Mg) alloy for biodegradable clips that reduces artifacts on CT imaging. This study aimed to examine the tolerance, biodegradability, and biocompatibility of the Mg alloy clips compared with those of standard titanium (Ti) clips in hepatectomy. METHODS: Thirty Wistar rats were divided into two groups based on the clip used (groups A and B). The vascular pedicle, including hepatic artery, portal vein, bile duct, and hepatic vein of the left lateral lobe, was ligated with the Ti clip in group A or the Mg alloy clip in group B, and then the left lateral lobe was removed. The rats were sacrificed at 1, 4, 12, 24, and 36 weeks after surgery. Clinical and histological evaluations were performed. Absorption rate was calculated by measuring the clip volume. RESULTS: Although the Mg alloy clips showed biodegradability over time, there were no significant differences in the serum concentration of Mg between the two groups. The remaining volume ratio of Mg alloy clips was 95.5, 94.3, 80.0, 36.2, and 16.7% at 1, 4, 12, 24, and 36 weeks, respectively. No side effects occurred. Most of the microscopic changes were similar in both groups. CONCLUSIONS: The new biodegradable Mg alloy clips are safe and feasible in vessel ligation for hepatectomy in a rat model and reduce artifacts in CT imaging compared with the standard Ti clips.