Factors affecting nonfunctioning small pancreatic neuroendocrine neoplasms and proposed new treatment strategies

BACKGROUND & AIMS

Despite previously reported treatment strategies for nonfunctioning small (≤20 mm) pancreatic neuroendocrine neoplasms (pNENs), uncertainties persist. We aimed to evaluate the surgically resected cases nonfunctioning small pNENs (NF-spNENs) in a large Japanese cohort to elucidate an optimal treatment strategy for NF-spNENs.

METHODS

In this Japanese multicenter study, data were retrospectively collected from patients who underwent pancreatectomy between January 1996 and December 2019, were pathologically diagnosed with pNEN, and were treated according to the WHO 2019 classification. Overall, 1,490 patients met the eligibility criteria, and 1,014 were included in the analysis cohort.

RESULTS

In the analysis cohort, 606 patients (59.8%) had NF-spNENs, with 82% classified as grade 1 (NET-G1) and 18% as grade 2 (NET-G2) or higher. The incidence of lymph node metastasis (N1) by grade was significantly higher in NET-G2 (G1: 3.1% vs. G2: 15.0%). Independent factors contributing to N1 were NET-G2 or higher and tumor diameter ≥15 mm. The predictive ability of tumor size for N1 was high. Independent factors contributing to recurrence included multiple lesions, NET-G2 or higher, tumor diameter ≥15 mm, and N1. However, the independent factor contributing to survival was tumor grade (NET-G2 or higher). The appropriate timing for surgical resection of NET-G1 and NET-G2 or higher was when tumors were >20 and >10 mm, respectively. For neoplasms with unknown preoperative grades, tumor size >15 mm was considered appropriate.

CONCLUSIONS

NF-spNENs are heterogeneous with varying levels of malignancy. Therefore, treatment strategies based on tumor size alone can be unreliable; personalized treatment strategies that consider tumor grading are preferable.

FBXW7 regulates the sensitivity of imatinib in gastrointestinal stromal tumors by targeting MCL1

BACKGROUND

Imatinib contributes to improving prognosis of high-risk or unresectable gastrointestinal stromal tumors (GISTs). As therapeutic efficacy is limited by imatinib resistance and toxicity, the exploration of predictive markers of imatinib therapeutic efficacy that enables patients to utilize more effective therapeutic strategies remains urgent.

METHODS

The correlation between FBXW7 and imatinib resistance via FBXW7-MCL1 axis was evaluated in vitro and in vivo experiments. The significance of FBXW7 as a predictor of imatinib treatment efficacy was examined in 140 high-risk patients with GISTs.

RESULTS

The ability of FBXW7 to predict therapeutic efficacy of adjuvant imatinib in high-risk GIST patients was determined through 5-year recurrence-free survival (RFS) rates analysis and multivariate analysis. FBXW7 affects imatinib sensitivity by regulating apoptosis in GIST-T1 cells. FBXW7 targets MCL1 to regulate apoptosis. MCL1 involves in the regulation of imatinib sensitivity through inhibiting apoptosis in GIST-T1 cells. FBXW7 regulates imatinib sensitivity by down-regulating MCL1 to enhance imatinib-induced apoptosis in vitro. FBXW7 regulates imatinib sensitivity of GIST cells by targeting MCL1 to predict efficacy of imatinib treatment in vivo.

CONCLUSIONS

FBXW7 regulates imatinib sensitivity by inhibiting MCL1 to enhance imatinib-induced apoptosis in GIST, and predicts efficacy of imatinib treatment in high-risk GIST patients treated with imatinib.

Survival outcome of patient with pT1N0 biliary tract cancer treated with surgery alone

INTRODUCTION

Adjuvant chemotherapy (AC) with S-1 or capecitabine monotherapy is now the standard of care for resected biliary tract cancer (BTC) according to the Adjuvant S-1 for Cholangiocarcinoma Trial (ASCOT) and the BILCAP study. Patients selection criteria, especially regarding pT1N0 BTC, differed in both trials. We aimed to clarify the survival outcomes regarding resected pT1N0 BTC without AC.

METHODS

Among patients with macroscopically complete resection for BTC treated without AC between September 1992 and December 2020, the survival outcomes of those with pT1N0 BTC, except for intrahepatic cholangiocarcinoma, according to the Union for International Cancer Control 7th and 8th edition (TNM7 and 8), were investigated.

RESULTS

Of 749 patients who underwent curative resection for BTC, 69 were identified as having pT1N0 BTC according to TNM8. Six patients (9 %) developed recurrence during the median follow-up period of 53 months (range: 14-263 months) with only one patient (2 %) being pT1N0 according to TNM7. Based on TNM8, the 5-year recurrence-free survival, disease-specific survival, and overall survival reached 90.7 % (95 % confidence interval [CI]: 80.3-95.7 %), 96.4 % (95 % CI: 86.1-99.1 %), and 85.3 % (95 % CI: 71.2-92.8 %), respectively. Perineural invasion (PNI) was significantly associated with recurrence, and the recurrence rate in patients with PNI reached as high as 40 %.

CONCLUSIONS

The survival outcomes regarding resected pT1N0 BTC according to TNM7 were excellent without AC; however, those of TNM8 were not, with PNI being associated with recurrence risk.

A multi-institutional randomized phase III study comparing minimally invasive distal pancreatectomy versus open distal pancreatectomy for pancreatic cancer; Japan Clinical Oncology Group study JCOG2202 (LAPAN study)

BACKGROUND

Minimally invasive distal pancreatectomy (MIDP), including laparoscopic and robotic distal pancreatectomy, has gained widespread acceptance over the last decade owing to its favorable short-term outcomes. However, evidence regarding its oncologic safety is insufficient. In March 2023, a randomized phase III study was launched in Japan to confirm the non-inferiority of overall survival in patients with resectable pancreatic cancer undergoing MIDP compared with that of patients undergoing open distal pancreatectomy (ODP).

METHODS

This is a multi-institutional, randomized, phase III study. A total of 370 patients will be enrolled from 40 institutions within 4 years. The primary endpoint of this study is overall survival, and the secondary endpoints include relapse-free survival, proportion of patients undergoing radical resection, proportion of patients undergoing complete laparoscopic surgery, incidence of adverse surgical events, and length of postoperative hospital stay. Only a credentialed surgeon is eligible to perform both ODP and MIDP. All ODP and MIDP procedures will undergo centralized review using intraoperative photographs. The non-inferiority of MIDP to ODP in terms of overall survival will be statistically analyzed. Only if non-inferiority is confirmed will the analysis assess the superiority of MIDP over ODP.

DISCUSSION

If our study demonstrates the non-inferiority of MIDP in terms of overall survival, it would validate its short-term advantages and establish its long-term clinical efficacy.

TRIAL REGISTRATION

This trial is registered with the Japan Registry of Clinical Trials as jRCT 1,031,220,705 [ https://jrct.niph.go.jp/en-latest-detail/jRCT1031220705 ].

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.

Intraoperative artificial intelligence system identifying liver vessels in laparoscopic liver resection: a retrospective experimental study

BACKGROUND

The precise recognition of liver vessels during liver parenchymal dissection is the crucial technique for laparoscopic liver resection (LLR). This retrospective feasibility study aimed to develop artificial intelligence (AI) models to recognize liver vessels in LLR, and to evaluate their accuracy and real-time performance.

METHODS

Images from LLR videos were extracted, and the hepatic veins and Glissonean pedicles were labeled separately. Two AI models were developed to recognize liver vessels: the "2-class model" which recognized both hepatic veins and Glissonean pedicles as equivalent vessels and distinguished them from the background class, and the "3-class model" which recognized them all separately. The Feature Pyramid Network was used as a neural network architecture for both models in their semantic segmentation tasks. The models were evaluated using fivefold cross-validation tests, and the Dice coefficient (DC) was used as an evaluation metric. Ten gastroenterological surgeons also evaluated the models qualitatively through rubric.

RESULTS

In total, 2421 frames from 48 video clips were extracted. The mean DC value of the 2-class model was 0.789, with a processing speed of 0.094 s. The mean DC values for the hepatic vein and the Glissonean pedicle in the 3-class model were 0.631 and 0.482, respectively. The average processing time for the 3-class model was 0.097 s. Qualitative evaluation by surgeons revealed that false-negative and false-positive ratings in the 2-class model averaged 4.40 and 3.46, respectively, on a five-point scale, while the false-negative, false-positive, and vessel differentiation ratings in the 3-class model averaged 4.36, 3.44, and 3.28, respectively, on a five-point scale.

CONCLUSION

We successfully developed deep-learning models that recognize liver vessels in LLR with high accuracy and sufficient processing speed. These findings suggest the potential of a new real-time automated navigation system for LLR.

Feasibility of S-1 adjuvant chemotherapy after major hepatectomy for biliary tract cancers: An exploratory subset analysis of JCOG1202

INTRODUCTION

Major hepatectomy (MH) may produce the impaired liver function and affect the feasibility of adjuvant chemotherapy in terms of early period after the surgery, but there have not been detailed investigations. JCOG1202 (UMIN000011688) is a randomized phase III trial demonstrating the superiority of adjuvant S-1 chemotherapy for biliary tract cancer (BTC). The aim of this study is to examine the influence of MH for BTC on adjuvant S-1.

MATERIALS AND METHODS

Of the total 424 patients, 207 received S-1 (S-1 arm) while the remaining 217 were not. We compared MH with non-major hepatectomy (NMH) for BTC.

RESULTS

In the S-1 arm, 42 had undergone MH, and 165 had undergone NMH. MH had similar pretreatment features to NMH, including the proportion of biliary reconstruction, to NMH, except for a lower platelet count (17.7 vs. 23.4 × 104/mm3, p < 0.0001) and lower serum albumin level (3.5 vs. 3.8 g/dL, p < 0.0001). The treatment completion proportion tended to be lower for MH than for NMH (59.5 % vs. 75.8 %; risk ratio, 0.786 [95 % confidence interval, 0.603-1.023], p = 0.0733), and the median dose intensity was lower as well (88.7 % vs. 99.6 %, p = 0.0358). The major reasons for discontinuation were biliary tract infections and gastrointestinal disorders after MH. The frequency of grade 3-4 biliary tract infection was 19.0 % in MH vs. 4.2 % in NMH.

CONCLUSION

The treatment completion proportion and dose intensity were lower in MH than in NMH. Caution should be exercised against biliary tract infections and gastrointestinal disorders during adjuvant S-1 after MH for BTC.

Common clinicopathological and immunological features of sarcomatoid carcinoma across organs: A histomorphology-based cross-organ study

Sarcomatoid carcinoma (SC), which can occur in any organ, is a rare disease. To elucidate common characteristics of SC beyond organs, we evaluated clinicopathological and immunological features of SC defined by the single histological criterion beyond organs compared to randomly matched conventional carcinoma (non-SC) adjusted for the disease stage. Immunological features were assessed by multiplex immunohistochemistry, comparing immune cell density in tumor tissues and tumor programmed death-ligand 1 (PD-L1) expression. A total of 101 patients with SC or non-SC (31 lung, 19 esophagus, 22 pancreas, 15 liver, 4 bile duct, 6 kidney, 2 uterus and 2 ovary) were identified among 7197 patients who underwent surgery at our institute (1997-2020). SC was significantly associated with worse survival (HR: 1.571; 95% CI: 1.084-2.277; P = .017). The frequency of postoperative progression within 6 months was significantly higher for SC patients (54% vs 28%; P = .002). The immune profiling revealed the densities of CD8+ T cells (130 vs 72 cells/mm2 ; P = .004) and tumor-associated macrophages (566 vs 413 cells/mm2 ; P < .0001) and the tumor PD-L1 expression score (40% vs 5%; P < .0001) were significantly higher in SCs than in non-SCs. Among 73 SC patients with postoperative progression, multivariate Cox regression analysis showed that immunotherapy tended to be associated with favorable survival (HR: 0.256; 95% CI: 0.062-1.057; P = .060). Collectively, SCs shared clinicopathological and immunological features across organs. Our study can initiate to standardize the pathological definition of SC and provide a rationale for the investigation and development for this rare disease in a cross-organ manner.

Adjuvant and neoadjuvant chemotherapy for biliary tract cancer: a review of randomized controlled trials

The first randomized controlled trial of adjuvant chemotherapy for biliary tract cancer was reported in 2002. Since then, studies have continued, with efficacy reported for capecitabine in 2018 and S-1 in 2023. Oral fluoropyrimidines have become established as the standard of care. This article reviews the evidence from the randomized controlled trials reported to date and those that are ongoing or from which results have not yet been reported.

Re-appraisal of the universal definition of tumor rupture among patients with high-risk gastrointestinal stromal tumors

Aim

Tumor rupture has been indicated as a risk factor for recurrence of gastrointestinal stromal tumors (GISTs). The universal definition of tumor rupture was proposed. This study evaluated whether the universal definition was more accurate in identification of GISTs with high recurrent risk than subjective judgment.

Methods

The study included 507 patients with high-risk GISTs who underwent complete resection between December 2012 and December 2015. We conducted a questionnaire survey in participating institutes to re-diagnose tumor rupture based on the universal definition according to their surgical and pathological findings. We compared the clinical outcomes of tumor rupture based on the definition to those based on the surgeon's judgment and clarified the clinical importance of the rupture.

Results

Sixty-four patients were initially registered to have tumor rupture by surgeon's judgment, and it became 90 patients who had tumor rupture after reevaluation. Although there were significant differences in recurrence-free survival (RFS) between no rupture and rupture for both initial registration and reevaluation (p = 0.002, <0.001, respectively), a significant difference in overall survival was only observed after reevaluation (p = 0.011). Tumor rupture was significantly associated with large tumor size, mixed cell type in histology, R1 resection, frequent adjuvant therapy and recurrence, but not with location, mitosis, and genotype. Adjuvant therapy more than 3 years improved RFS of patients with tumor rupture.

Conclusion

This study suggested that tumor rupture based on the universal definition more accurately identified GISTs with poor prognostic outcomes than the subjective judgment.

Relationships between physical and immunological tumor microenvironment in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is physically palpated as a hard tumor with an unfavorable prognosis. Assessing physical features and their association with pathological features could help to elucidate the mechanism of physical abnormalities in cancer tissues. A total of 93 patients who underwent radical surgery for pancreatic and bile duct cancers at a single center hospital during a 28-month period were recruited for this study that aimed to estimate the stiffness of PDAC tissues compared to the other neoplasms and assess relationships between tumor stiffness and pathological features. Physical alterations and pathological features of PDAC, with or without preoperative therapy, were analyzed. The immunological tumor microenvironment was evaluated using multiplexed fluorescent immunohistochemistry. The stiffness of PDAC correlated with the ratio of Azan-Mallory staining, α-smooth muscle actin, and collagen I-positive areas of the tumors. Densities of CD8+ T cells and CD204+ macrophages were associated with tumor stiffness in cases without preoperative therapy. Pancreatic ductal adenocarcinoma treated with preoperative therapy was softer than that without, and the association between tumor stiffness and immune cell infiltration was not shown after preoperative therapy. We observed the relationship between tumor stiffness and immunological features in human PDAC for the first time. Immune cell densities in the tumor center were smaller in hard tumors than in soft tumors without preoperative therapies. Preoperative therapy could alter physical and immunological aspects, warranting further study. Understanding of the correlations between physical and immunological aspects could lead to the development of new therapies.

Liver functional assessment using time-associated change in the liver-to-spleen signal intensity ratio on enhanced magnetic resonance imaging: a retrospective study

BACKGROUND

Liver-to-spleen signal intensity ratio (LSR) is evaluated by magnetic resonance imaging (MRI) in the hepatobiliary phase and has been reported as a useful radiological assessment of regional liver function. However, LSR is a passive (non-time-associated) assessment of liver function, not a dynamic (time-associated) assessment. Moreover, LSR shows limitations such as a dose bias of contrast medium and a timing bias of imaging. Previous studies have reported the advantages of time-associated liver functional assessment as a precise assessment of liver function. For instance, the indocyanine green (ICG) disappearance rate, which is calculated from serum ICG concentrations at multiple time points, reflects a precise preoperative liver function for predicting post-hepatectomy liver failure without the dose bias of ICG or the timing bias of blood sampling. The aim of this study was to develop a novel time-associated radiological liver functional assessment and verify its correlation with traditional liver functional parameters.

METHODS

A total of 279 pancreatic cancer patients were evaluated to clarify fundamental time-associated changes to LSR in normal liver. We defined the time-associated radiological assessment of liver function, calculated using information on LSR from four time points, as the "LSR increasing rate" (LSRi). We then investigated correlations between LSRi and previous liver functional parameters. Furthermore, we evaluated how timing bias and protocol bias affect LSRi.

RESULTS

Significant correlations were observed between LSRi and previous liver functional parameters such as total bilirubin, Child-Pugh grade, and albumin-bilirubin grade (P < 0.001 each). Moreover, considerably high correlations were observed between LSRi calculated using four time points and that calculated using three time points (r > 0.973 each), indicating that the timing bias of imaging was minimal.

CONCLUSIONS

This study propose a novel time-associated radiological assessment, and revealed that the LSRi correlated significantly with traditional liver functional parameters. Changes in LSR over time may provide a superior preoperative assessment of regional liver function that is better for predicting post-hepatectomy liver failure than LSR using the hepatobiliary phase alone.

Risk factors for early relapse in patients with biliary tract cancers who underwent curative resection: An exploratory subgroup analysis of JCOG1202

541

Background: Relapse after highly invasive surgery for biliary tract cancers (BTCs), especially in the early postoperative period, causes medical, psychological, social, and economic disadvantages to the patients. However, approximately 30% of patients with curatively resected BTCs experience relapse within the first 12 months. JCOG1202 (UMIN000011688) is a randomized phase III trial conducted in patients with resected BTCs showing the benefit of adjuvant S-1 for overall survival. This study aimed to investigate the risk factors for early relapse of resected BTCs in the JCOG1202 cohort. Methods: Of the 440 patients enrolled in the JCOG1202, 217 patients who received surgery alone (arm A) and 207 patients who received adjuvant S-1 (arm B) were eligible and included in this analysis. Early relapse was defined as relapse or death within 12 months after enrollment. Predictive factors for early relapse were assessed using logistic regression analyses. Results: Postoperative early relapse was observed in 59 (27.2%) and 38 (18.4%) of patients in arm A and arm B, respectively. In multivariable logistic regression analysis for the 424 eligible patients, postoperative CA19-9 levels >37 u/ml (odds ratio (OR): 2.790, 95% confidence interval (CI): 1.262-6.170), poorly differentiation (vs. well-differentiated/papillary) (OR: 4.746, 95% CI:1.927-11.688), moderate differentiation (vs. well-differentiated/papillary) (OR: 1.955, 95% CI:1.071-3.567), lymph node metastases > 4 (vs. 0) (OR: 3.991, 95% CI: 1.674-9.514), lymph node metastases 1-3 (vs. 0) (OR: 2.661, 95% CI: 1.471-4.814), and presence of residual tumor (OR: 2.171, 95% CI: 1.070-4.408) were independent risk factors for early relapse. Importantly, adjuvant S-1 chemotherapy significantly reduced early relapse (OR: 0.491, 95% CI: 0.290-0.833). Similar results were observed in arm B. Conclusions: Postoperative CA19-9 level, tumor differentiation, lymph node metastases, and the residual tumor significantly impact early relapse in patients with curatively resected BTCs. Although adjuvant S-1 chemotherapy was effective in reducing early relapse, similar factors tended to be the risk factors in patients receiving adjuvant S-1 chemotherapy. Patients at high risk of early relapse may need more intensive perioperative therapy. Clinical trial information: UMIN000011688 .

Randomized multicenter phase III trial of neoadjuvant gemcitabine + cisplatin + S-1 (GCS) versus surgery first for resectable biliary tract cancer (JCOG1920: NABICAT)

TPS621

Background: Biliary tract cancer (BTC) is a highly lethal disease. The prognosis remains poor even after macroscopically curative resection due to the high recurrence rate. Therefore, developing effective adjuvant therapy is essential to improve treatment outcomes. In 2021, a phase III trial (JCOG1202: ASCOT) showed the superiority of adjuvant S-1 chemotherapy to surgery alone in the overall survival (OS) in BTC patients with curative resection (hazard ratio [HR] 0.694, 95% confidence interval [CI]: 0.514–0.935; p=0.008). Consequently, adjuvant S-1 chemotherapy has become the standard of care for resected BTC. In contrast, only a few studies have been conducted to assess the effectiveness of neoadjuvant therapy for BTC until now. Recently, a phase III trial (KHBO1401-MITSUBA) demonstrated the superiority of gemcitabine + cisplatin + S-1 (GCS) therapy to gemcitabine + cisplatin in patients with advanced unresectable BTC in terms of OS (HR 0.79, 90% CI: 0.628–0.996; p=0.046). The GCS arm showed a high response rate (41.5%), with promise in a neoadjuvant setting. This phase III trial aims to confirm the superiority of neoadjuvant GCS to surgery first in patients with resectable BTC. Methods: The main eligibility criteria are: (1) histologically diagnosed with adenocarcinoma or adenosquamous carcinoma; (2) diagnosed as resectable BTC with clinical stage II–IVA for perihilar bile duct cancer, stage IB–III for distal bile duct cancer, stage IIIA–IVA for gallbladder cancer, stage IIA–III for ampullary cancer, or stage III–IVA/stage IVB (T4N1M0) for intrahepatic bile duct cancer by diagnostic imaging; (3) Eastern Cooperative Oncology Group Performance Status 0 or 1; and (4) age ≥20 years. Enrolled patients are randomized 1:1 to neoadjuvant GCS + surgery + adjuvant S-1 or surgery + adjuvant S-1 regarding the center and primary site (perihilar/distal/gall bladder/ampulla of Vater/intrahepatic) by the minimization method. The GCS regimen comprises gemcitabine (1000 mg/m2) and cisplatin (25 mg/m2) on day 1 and S-1 (80-120 mg/day) on days 1–7, every 2 weeks for 3 courses. After surgery, S-1 (80-120 mg/day) for 4 weeks-on, 2 weeks-off, for a total of 4 cycles, is administered in both arms. The primary endpoint is OS, and secondary endpoints are progression-free survival (PFS), OS and PFS in patients who underwent R0/R1 resection, incidence of non-resection, %R0 resection, %R0/R1 resection, %lymph node metastasis, postoperative complications of Clavien–Dindo Grade IIIa or severer, serious adverse events, and objective response rate in the GCS arm. We calculated a sample size of 330 patients to obtain 70% power at a one-sided alpha error of 5%, a hazard ratio of 0.698 (3-year OS 67% vs 75.6%), an accrual period of 5 years, and a follow-up period of 3 years. The patient accrual was started in March 2021, and 126 patients have been enrolled as of September 2022. Clinical trial information: jRCTs031200388 .

A novel predictive model for postoperative delirium using multiple geriatric screening factors

OBJECTIVES

The purpose of this study was to develop a new composite score to accurately predict postoperative delirium (POD) after major urological cancer surgery.

METHODS

Our retrospective analysis included, in total, 449 consecutive patients who experienced major urological cancer surgery and a preoperative geriatric functional assessment at our institution (development cohort). Geriatric functional assessments included Geriatric 8, Instrumental Activities of Daily Living, and mini-cognitive assessment instrument (Mini-Cog). Multivariate analysis was used to identify factors related to POD and combined to create a predictive score. The composite score was externally validated using a cohort of 92 consecutive pancreatic cancer patients who underwent pancreaticoduodenectomy and a preoperative geriatric functional assessment (validation cohort). The predictive accuracy and performance of the composite score were evaluated using the area under the receiver operating characteristic curves (AUC) and calibration plots.

RESULTS

In multivariate analysis of a development cohort, the following factors were significantly associated with POD: a Mini-Cog score of <3 (odds ratio [OR] = 9.5; p < 0.001), disability in the responsibility for medication (OR = 4.1; p = 0.03), and the preoperative use of benzodiazepine (OR = 6.4; p < 0.001). The composite score of these three factors showed excellent discrimination in predicting POD, with AUC values of 0.819 and 0.804 in development and validation cohorts, respectively. Calibration plots showing predicted probability and actual observation in both cohorts showed good agreement.

CONCLUSIONS

A combined model of Mini-Cog, a disability in the responsibility for medication, and preoperative benzodiazepine use showed excellent discriminative power in predicting POD.

Early postoperative decrease of skeletal muscle mass predicts recurrence and poor survival after surgical resection for perihilar cholangiocarcinoma

BACKGROUND

Preoperative sarcopenia is a predictor of poor survival in cancer patients. We hypothesized that sarcopenia could progress as occult metastasis arose, especially after highly invasive surgery for highly aggressive malignancy. This study aimed to evaluate the associations of postoperative changes in skeletal muscle mass volume with survival outcomes in patients who underwent surgery for perihilar cholangiocarcinoma.

METHODS

Fifty-six patients who underwent major hepatectomy with extrahepatic bile duct resection for perihilar cholangiocarcinoma were studied. The skeletal muscle index (SMI) at the third lumbar vertebra was calculated from axial computed tomography images taken preoperatively and 3-6 months postoperatively (early postoperative period). The associations of clinicopathological variables, including changes of SMI after surgery, with overall survival and recurrence-free survival were evaluated. Moreover, the associations of decreased SMI and elevated serum carbohydrate antigen 19-9 level with early recurrence and poor survival was compared.

RESULTS

Among 56 patients, 26 (46%) had sarcopenia preoperatively and SMI decreased in 29 (52%) in the early postoperative period. During the median follow-up of 57.9 months, 35 patients (63%) developed recurrence and 29 (50%) died. Decreased SMI in the early postoperative period was independently associated with a shorter overall survival (hazard ratio, 2.39; 95% confidence interval, 1.00-6.18; P = 0.049) and a shorter recurrence-free survival (hazard ratio, 2.14; 95% confidence interval, 1.04-4.57; P = 0.039), whereas elevated carbohydrate antigen 19-9 level was not.

CONCLUSIONS

Decreased SMI in the early postoperative period may be used as a predictor for recurrence and poor survival in patients undergoing surgery for perihilar cholangiocarcinoma.

Laparoscopic liver resection can be performed safely without intraoperative drain placement

BACKGROUND

Laparoscopic liver resection (LLR) has become a standardized procedure with advances in surgical techniques and perioperative management in the last decade; however, the necessity of routine drain placement in LLR has not been fully investigated. This study aimed to evaluate the need for intraoperative drain placement (IDP) in LLR.

METHODS

A total of 607 patients who underwent LLR for liver tumor at our institution between January 2015 and August 2021 were studied. Clinicopathological data, including intraoperative factors and postoperative outcomes, were compared between patients with and without IDP before and after propensity score matching. Variables shown to be different between the two groups were used for matching. Then, risk analysis for additional drainage procedure after surgery was performed in the original and matched cohorts.

RESULTS

Of the 607 patients, 4 (0.7%) and 14 (2.3%) developed incisional and organ/space surgical site infections, respectively, and 9 (1.5%) required additional drainage procedure after surgery. Ninety-three patients (15.3%) underwent IDP. The incidence and severity of postoperative complications were similar between patients with and without IDP in both the original and matched cohorts. In the matched cohort, simultaneous colectomy (odds ratio, 14.051, 95% confidence interval, 1.103-178.987; P = 0.042), rather than IDP (odds ratio, 1.836, 95% confidence interval, 0.157-21.509; P = 0.629), was independently associated with the risk of additional drainage procedure after surgery.

CONCLUSIONS

This study demonstrated that LLR could be performed safely without IDP.

Automated surgical workflow identification by artificial intelligence in laparoscopic hepatectomy: Experimental research

BACKGROUND

To perform accurate laparoscopic hepatectomy (LH) without injury, novel intraoperative systems of computer-assisted surgery (CAS) for LH are expected. Automated surgical workflow identification is a key component for developing CAS systems. This study aimed to develop a deep-learning model for automated surgical step identification in LH.

MATERIALS AND METHODS

We constructed a dataset comprising 40 cases of pure LH videos; 30 and 10 cases were used for the training and testing datasets, respectively. Each video was divided into 30 frames per second as static images. LH was divided into nine surgical steps (Steps 0-8), and each frame was annotated as being within one of these steps in the training set. After extracorporeal actions (Step 0) were excluded from the video, two deep-learning models of automated surgical step identification for 8-step and 6-step models were developed using a convolutional neural network (Models 1 & 2). Each frame in the testing dataset was classified using the constructed model performed in real-time.

RESULTS

Above 8 million frames were annotated for surgical step identification from the pure LH videos. The overall accuracy of Model 1 was 0.891, which was increased to 0.947 in Model 2. Median and average accuracy for each case in Model 2 was 0.927 (range, 0.884-0.997) and 0.937 ± 0.04 (standardized difference), respectively. Real-time automated surgical step identification was performed at 21 frames per second.

CONCLUSIONS

We developed a highly accurate deep-learning model for surgical step identification in pure LH. Our model could be applied to intraoperative systems of CAS.

Histological tumor necrosis in pancreatic cancer after neoadjuvant therapy

The pathological prognostic factors in pancreatic cancer patients who have received neoadjuvant therapy (NAT) are still elusive. The aim of the present study was to investigate the prognostic potential of histological tumor necrosis (HTN) in patients who received NAT and to evaluate tumor changes after NAT. HTN was studied in 44 pancreatic cancer patients who received NAT followed by surgery (NAT group) compared with 263 patients who received upfront surgery (UFS group). The prognostic factors in the NAT group were analyzed, and carbonic anhydrase 9 (CA‑9) expression was compared between the NAT and USF group to evaluate the hypoxic microenvironment changes during NAT. HTN was found in 15 of 44 patients in the NAT group, and its frequency was lower than that in the UFS group (34 vs. 51%, P=0.04). Cox proportional hazards models identified HTN as an independent risk factor for relapse‑free survival in the NAT group [risk ratio (RR), 5.60; 95% confidence interval (CI): 2.27‑14.26, P<0.01]. Significant correlations were found between HTN and CA‑9 expression both in the NAT and UFS groups (P<0.01 for both). CA‑9 expression was significantly upregulated in the NAT group overall, although this upregulation was specifically induced in patients without HTN. In conclusion, HTN was a poor prognostic factor in pancreatic cancer patients receiving NAT followed by surgery, and the present study suggests a close association between HTN and tumor hypoxia. Increased hypoxia after NAT may support the thesis for re‑engineering the hypoxia‑alleviating tumor microenvironment in NAT regimens for pancreatic cancer.

An International Retrospective Observational Study of Liver Functional Deterioration after Repeat Liver Resection for Patients with Hepatocellular Carcinoma

Simple Summary

For 657 cases of segment or less repeat liver resection with results of plasma albumin and bilirubin levels and platelet counts before and 3 months after surgery, the indicators were compared before and after surgery. There were 268 open repeat after open and 224 cases laparoscopic repeat after laparoscopic liver resection. The background factors and liver functional indicators before and after surgery, and the changes were compared between both groups. Plasma levels of albumin (p = 0.006) and total bilirubin (p = 0.01) were decreased, and ALBI score (p = 0.001) indicated worse liver function after surgery. Though laparoscopic group had poorer performance status and liver function, changes of the values and overall survivals were similar between both groups. Plasma levels of albumin and bilirubin and ALBI score could be the liver functional indicators for liver functional deterioration after liver resection. The laparoscopic group with poorer conditions showed a similar deterioration of liver function and overall survival to the open group.

Abstract

Whether albumin and bilirubin levels, platelet counts, ALBI, and ALPlat scores could be useful for the assessment of permanent liver functional deterioration after repeat liver resection was examined, and the deterioration after laparoscopic procedure was evaluated. For 657 patients with liver resection of segment or less in whom results of plasma albumin and bilirubin levels and platelet counts before and 3 months after surgery could be retrieved, liver functional indicators were compared before and after surgery. There were 268 patients who underwent open repeat after previous open liver resection, and 224 patients who underwent laparoscopic repeat after laparoscopic liver resection. The background factors, liver functional indicators before and after surgery and their changes were compared between both groups. Plasma levels of albumin (p = 0.006) and total bilirubin (p = 0.01) were decreased, and ALBI score (p = 0.001) indicated worse liver function after surgery. Laparoscopic group had poorer preoperative performance status and liver function. Changes of liver functional values before and after surgery and overall survivals were similar between laparoscopic and open groups. Plasma levels of albumin and bilirubin and ALBI score could be the indicators for permanent liver functional deterioration after liver resection. Laparoscopic group with poorer conditions showed the similar deterioration of liver function and overall survivals to open group.

The component with abundant immune-related cells in combined hepatocellular cholangiocarcinoma identified by cluster analysis

Combined hepatocellular cholangiocarcinoma (cHCC‐CCA) is a heterogeneous tumor sharing histological features with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). The tumor immune microenvironment (TIME) of cHCC‐CCA is unclear. We compared the TIME of cHCC‐CCA with that of HCC and iCCA. Twenty‐three patients with cHCC‐CCA after hepatectomy were evaluated in this study. Twenty‐three patients with iCCA and HCC were also included. iCCA was matched for size, and HCC was matched for size and hepatitis virus infection with cHCC‐CCA. Immune‐related cells among the iCCA‐component of cHCC‐CCA (C‐com), HCC‐component of cHCC‐CCA (H‐com), iCCA, and HCC were assessed using multiplex fluorescence immunohistochemistry. Among C‐com, H‐com, iCCA, and HCC, multiple comparisons and cluster analysis with k‐nearest neighbor algorithms were performed using immunological variables. Although HCC had more T lymphocytes and lower PD‐L1 expression than iCCA (P < 0.05), there were no significant differences in immunological variables between C‐com and H‐com. C‐com tended to have more T lymphocytes than iCCA (P = 0.09), and C‐com and H‐com had fewer macrophages than HCC (P < 0.05). In cluster analysis, all samples were classified into two clusters: one cluster had more immune‐related cells than the other, and 12 of 23 H‐com and eight of 23 C‐com were identified in this cluster. The TIME of C‐com and H‐com may be similar, and some immunological features in these components were different from those in HCC and some iCCA. Cluster analysis identified components with abundant immune‐related cells in cHCC‐iCCA.

The Tokyo 2020 terminology of liver anatomy and resections: Updates of the Brisbane 2000 system

BACKGROUND

The Brisbane 2000 Terminology for Liver Anatomy and Resections, based on Couinaud's segments, did not address how to identify segmental borders and anatomic territories of less than one segment. Smaller anatomic resections including segmentectomies and subsegmentectomies, have not been well defined. The advent of minimally invasive liver resection has enhanced the possibilities of more precise resection due to a magnified view and reduced bleeding, and minimally invasive anatomic liver resection (MIALR) is becoming popular gradually. Therefore, there is a need for updating the Brisbane 2000 system, including anatomic segmentectomy or less. An online "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was hosted on February 23, 2021.

METHODS

The Steering Committee invited 34 international experts from around the world. The Expert Committee (EC) selected 12 questions and two future research topics in the terminology session. The EC created seven tentative definitions and five recommendations based on the experts' opinions and the literature review performed by the Research Committee. Two Delphi Rounds finalized those definitions and recommendations.

RESULTS

This paper presents seven definitions and five recommendations regarding anatomic segmentectomy or less. In addition, two future research topics are discussed.

CONCLUSIONS

The PAM-HBP Surgery Consensus has presented the Tokyo 2020 Terminology for Liver Anatomy and Resections. The terminology has added definitions of liver anatomy and resections that were not defined in the Brisbane 2000 system.

Minimally invasive anatomic liver resection: Results of a survey of world experts

BACKGROUND

Although the number of minimally invasive liver resections (MILRs) has been steadily increasing in many institutions, minimally invasive anatomic liver resection (MIALR) remains a complicated procedure that has not been standardized. We present the results of a survey among expert liver surgeons as a benchmark for standardizing MIALR.

METHOD

We administered this survey to 34 expert liver surgeons who routinely perform MIALR. The survey contained questions on personal experience with liver resection, inflow/outflow control methods, and identification techniques of intersegmental/sectional planes (IPs).

RESULTS

All 34 participants completed the survey; 24 experts (70%) had more than 11 years of experience with MILR, and over 80% of experts had performed over 100 open resections and MILRs each. Regarding the methods used for laparoscopic or robotic anatomic resection, the Glissonean approach (GA) was a more frequent procedure than the hilar approach (HA). Although hepatic veins were considered essential landmarks, the exposure methods varied. The top three techniques that the experts recommended for identifying IPs were creating a demarcation line, indocyanine green negative staining method, and intraoperative ultrasound.

CONCLUSION

Minimally invasive anatomic liver resection remains a challenging procedure; however, a certain degree of consensus exists among expert liver surgeons.

Expert Consensus Guidelines: How to safely perform minimally invasive anatomic liver resection

BACKGROUND

The concept of minimally invasive anatomic liver resection (MIALR) is gaining popularity. However, specific technical skills need to be acquired to safely perform MIALR. The "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was developed as a special program during the 32nd meeting of the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS).

METHODS

Thirty-four international experts gathered online for the consensus. A Research Committee performed a comprehensive literature review, classifying studies according to the Scottish Intercollegiate Guidelines Network method. Based on the literature review and experts' opinions, tentative recommendations were drafted and circulated among experts using online Delphi Rounds. Finally, formulated recommendations were presented online in the Expert Consensus Meeting of the JSHBPS on February 23rd, 2021. The final recommendations were validated and finalized by the 2nd Delphi Round in May 2021.

RESULTS

Seven clinical questions were selected, and 22 recommendations were formulated. All recommendations reached more than 85% consensus among experts at the final Delphi Round.

CONCLUSIONS

The Expert Consensus Meeting for safely performing MIALR has presented a set of clinical guidelines based on available literature and experts' opinions. We expect these guidelines to have a favorable effect on the safe implementation and development of MIALR.

APC mutations are common in adenomas but infrequent in adenocarcinomas of the non-ampullary duodenum

BACKGROUND

Recent studies highlighted the clinicopathological heterogeneity of non-ampullary duodenal adenomas and adenocarcinomas, but the detailed process of the malignant transformation remains unclear.

METHODS

We analyzed 144 adenomas and 54 adenocarcinomas of the non-ampullary duodenum for immunohistochemical phenotypes, genetic alterations, and mismatch repair (MMR) status to probe their histogenetic relationship.

RESULTS

The median ages of patients with adenoma and adenocarcinoma were the same (66 years). Adenomas were histologically classified as intestinal-type adenoma (n = 124), pyloric gland adenoma (PGA, n = 10), gastric-type adenoma, not otherwise specified (n = 9), and foveolar-type adenoma (n = 1). Protein-truncating APC mutations were highly frequent in adenomas (85%), with the highest prevalence in intestinal-type adenomas (89%), but rare in adenocarcinomas (9%; P = 2.1 × 10^-23). Close associations between phenotypic marker expression and genetic alterations were observed in adenomas, but not in adenocarcinomas, excluding the common association between GNAS mutations and MUC5AC expression. MMR deficiency was more frequent in adenocarcinomas (20%) than in adenomas (1%; P = 2.6 × 10^-6). One MMR-deficient adenoma and three MMR-deficient adenocarcinomas occurred in patients with Lynch syndrome. Additionally, three other patients with an MMR-deficient adenocarcinoma fulfilled the revised Bethesda criteria.

CONCLUSION

The discrepant APC mutation frequency between adenomas and adenocarcinomas suggests that APC-mutated adenomas, which constitute the large majority of non-ampullary duodenal adenomas, are less prone to malignant transformation. Non-ampullary duodenal adenocarcinomas frequently exhibit MMR deficiency and should be subject to MMR testing to determine appropriate clinical management, including the identification of patients with Lynch syndrome.

BRAF V600E potentially determines "Oncological Resectability" for "Technically Resectable" colorectal liver metastases

Despite reports on poor survival outcomes after hepatectomy for colorectal liver metastases (CRLM) with BRAF V600E mutation (mBRAF) exist, the role of mBRAF testing for technically resectable cases remains unclear. A single-center retrospective study was performed to investigate the survival outcomes of patients who underwent upfront hepatectomy for solitary resectable CRLM with mBRAF between January 2005 and December 2017 and to compare them with those of unresectable cases with mBRAF. Of 172 patients who underwent initial hepatectomy for solitary resectable CRLM, mBRAF, RAS mutations (mRAS), and wild-type RAS/BRAF (wtRAS/BRAF) were observed in 5 (2.9%), 73 (42.4%), and 93 (54.7%) patients, respectively. With a median follow-up period of 72.8 months, mBRAF was associated with a significantly shorter OS (median, 14.4 months) than wtRAS/BRAF (median, not reached [NR]) (hazard ratio [HR], 27.6; p < 0.001) and mRAS (median, NR) (HR, 9.9; p < 0.001), and mBRAF had the highest HR among all the indicators in the multivariable analysis (HR, 17.0; p < 0.001). The median OS after upfront hepatectomy for CRLM with mBRAF was identical to that of 28 unresectable CRLM with mBRAF that were treated with systemic chemotherapy (median, 17.2 months) (HR, 0.78; p = 0.65). When technically resectable CRLM are complicated with mBRAF, its survival outcome becomes as poor as unresectable cases; therefore, those with mBRAF should be considered as oncologically unresectable. Patients with CRLM should undergo pre-treatment mBRAF testing regardless of technical resectability. Clinical trial registration number: UMIN000034557.

Multicenter Propensity Score-Based Study of Laparoscopic Repeat Liver Resection for Hepatocellular Carcinoma: A Subgroup Analysis of Cases with Tumors Far from Major Vessels

Simple Summary

Less morbidity is considered among the advantages of laparoscopic liver resection for HCC patients. However, our previous international, multi-institutional study of laparoscopic repeat liver resection (LRLR) failed to prove it. We hypothesize that these results may be since the study included complex cases performed during the procedure’s developing stage. To examine it, subgroup analysis based on propensity score were performed, defining the proximity of the tumors to major vessels as the complexity. A propensity score matching earned 115 each patient of LRLR and open repeat liver resection (ORLR) without the proximity to major vessels, and the outcomes were compared. With comparable operation time and long-term outcome, less blood loss and less morbidity were shown in LRLR group than ORLR. Even in its worldwide developing stage, LRLR for HCC patients could be beneficial in blood loss and morbidity for the patients with less complexity in surgery.

Abstract

Less morbidity is considered among the advantages of laparoscopic liver resection (LLR) for HCC patients. However, our previous international, multi-institutional, propensity score-based study of emerging laparoscopic repeat liver resection (LRLR) failed to prove this advantage. We hypothesize that these results may be since the study included complex LRLR cases performed during the procedure’s developing stage. To examine it, subgroup analysis based on propensity score were performed, defining the proximity of the tumors to major vessels as the indicator of complex cases. Among 1582 LRLR cases from 42 international high-volume liver surgery centers, 620 cases without the proximity to major vessels (more than 1 cm far from both first–second branches of Glissonian pedicles and major hepatic veins) were selected for this subgroup analysis. A propensity score matching (PSM) analysis was performed based on their patient characteristics, preoperative liver function, tumor characteristics and surgical procedures. One hundred and fifteen of each patient groups of LRLR and open repeat liver resection (ORLR) were earned, and the outcomes were compared. Backgrounds were well-balanced between LRLR and ORLR groups after matching. With comparable operation time and long-term outcome, less blood loss (283.3±823.0 vs. 603.5±664.9 mL, p = 0.001) and less morbidity (8.7 vs. 18.3 %, p = 0.034) were shown in LRLR group than ORLR. Even in its worldwide developing stage, LRLR for HCC patients could be beneficial in blood loss and morbidity for the patients with less complexity in surgery.

Recognition and pathological features of periampullary region adenocarcinoma with an indeterminable origin

Determination of the primary tumor in periampullary region carcinomas can be difficult, and the pathological assessment and clinicopathological characteristics remain elusive. In this study, we investigated the current recognition and practices for periampullary region adenocarcinoma with an indeterminable origin among expert pathologists through a cognitive survey. Simultaneously, we analyzed a prospective collection of cases with an indeterminable primary tumor diagnosed from 2008 to 2018 to elucidate their clinicopathological features. All cases with pathological indeterminable primary tumors were reported and discussed in a clinicopathological conference to elucidate if it was possible to distinguish the primary tumor clinically and pathologically. From the cognitive survey, over 85% of the pathologists had experienced cases with indeterminable primary tumors; however, 70% of the cases was reported as pancreatic cancer without definitive grounds. Interpretation of the main tumor mass varied, and no standardized method was developed to determine the primary tumor. During a prospective study, 42 of the 392 periampullary carcinoma cases (10.7%) were considered as tumors with a pathological indeterminable origin. After the clinicopathological conferences, 21 (5.4%) remained indeterminable and were considered final indeterminable cases. Histological studies showed that the tumors spread along both the bile duct and main pancreatic duct; this was the most representative finding of the final indeterminable cases. This study is the first to elucidate and recognize the current clinicopathological features of periampullary region adenocarcinomas with an indeterminable origin. Adequate assessment of primary tumors in periampullary region carcinomas will help to optimize epidemiological data of pancreatic and bile duct cancer.

The immunological impact of preoperative chemoradiotherapy on the tumor microenvironment of pancreatic cancer

Several therapeutic regimens, including neoadjuvant chemoradiation therapy (NACRT), have been reported to serve as anticancer immune effectors. However, there remain insufficient data regarding the immune response after NACRT in pancreatic ductal adenocarcinoma (PDAC) patients. Data from 40 PDAC patients that underwent surgical resection after NACRT (NACRT group) and 30 PDAC patients that underwent upfront surgery (US group) were analyzed to examine alterations in immune cell counts/distribution using a multiplexed fluorescent immunohistochemistry system. All immune cells were more abundant in the cancer stroma than in the cancer cell nest regardless of preoperative therapy. Although the stromal counts of CD4+ T cells, CD20+ B cells, and Foxp3+ T cells in the NACRT group were drastically decreased in comparison with those of the US group, counts of these cell types in the cancer cell nest were not significantly different between the two groups. In contrast, CD204+ macrophage counts in the cancer stroma were similar between the NACRT and US groups, while those in the cancer cell nests were significantly reduced in the NACRT group. Following multivariate analysis, only a high CD204+ macrophage count in the cancer cell nest remained an independent predictor of shorter relapse-free survival (odds ratio = 2.37; P = .033). NACRT for PDAC decreased overall immune cell counts, but these changes were heterogeneous within the cancer cell nests and cancer stroma. The CD204+ macrophage count in the cancer cell nest is an independent predictor of early disease recurrence in PDAC patients after NACRT.

The Assessment of Regional Liver Function Before Major Hepatectomy Using Magnetic Resonance Imaging

BACKGROUND

The liver-to-spleen signal intensity ratio (LSR) on magnetic resonance imaging with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid has been used as a parameter to assess liver function. LSR of the future remnant liver region (FR-LSR) is included in preoperative assessment of regional liver function. The aim of this study was to investigate the predictability of post-hepatectomy liver failure (PHLF) by FR-LSR.

METHODS

Between May 2013 and May 2019, 127 patients underwent standardized EOB-MRI for diagnosis of liver tumor before major hepatectomy. The FR-LSR on EOB-MRI was calculated by a semiautomated three-dimensional volumetric analysis system. The cutoff value of FR-LSR in association with clinically relevant PHLF was determined according to the areas under the receiver operating characteristic curves. Then, FR-LSR and clinical variables were analyzed to assess the risk of clinically relevant PHLF.

RESULTS

In patients with preoperative biliary drainage, metastatic liver tumor, estimated future remnant liver volume <50%, biliary reconstruction, operation time ≥ 480 min, estimated blood loss ≥ 1000 g, blood transfusion and a FR-LSR < 2.00 were associated with clinically relevant PHLF (P < .05 for all) in univariable analysis. The liver-to-spleen signal intensity ratio of the future remnant liver region < 2.00 was the only independent risk factor for clinically relevant PHLF in multivariable risk analysis (OR, 27.90; 95% CI: 7.99-136.40; P < .05).

DISCUSSION

The present study revealed that FR-LSR calculated using a 3-dimensional volumetric analysis system was an independent risk factor for clinically relevant PHLF. The liver-to-spleen signal intensity ratio of the future remnant liver region might be a reliable preoperative parameter in liver functional assessment, enabling safe performance of major hepatectomy.

Impact of previous history of choledochojejunostomy on the incidence of organ/space surgical site infection after hepatectomy

PURPOSE

Impact of previous history of choledochojejunostomy (PCJ) on the incidence of organ/space surgical site infection (SSI) after hepatectomy remains unclear. The aim of this study was to investigate the incidence and causes of SSI after hepatectomy.

METHODS

Patients who underwent hepatectomy of ≤1 Couinaud's sector between January 2011 and September 2019 were retrospectively analyzed. Incidence of and risk factors for organ/space SSI (Clavien-Dindo grade ≥2) after hepatectomy were investigated.

RESULTS

Among 750 hepatectomies, 18 patients (2.4%) had a medical history of PCJ. Incidence of organ/space SSI was higher in patients with PCJ (50%) than in those without PCJ (3%, P < 0.001), and the trend was consistent even after estimated propensity score matched cohort. Multivariate analysis showed PCJ was a strong risk factor for organ/space SSI (grade ≥2), with the highest odds ratios (OR) among all other clinicopathological risk factors (OR, 32.25; P < 0.001). Among hepatectomies with PCJ, pneumobilia (OR, 12.25; P = 0.015), operation time ≥171 min (OR, 12.25; P = 0.016), and liver steatosis (OR, 24.00; P ≤ 0.005) were associated with organ/space SSI after hepatectomy.

CONCLUSION

Previous history of choledochojejunostomy was a strong risk factor for organ/space SSI after hepatectomy. The high rate of organ/space SSI after hepatectomy with PCJ might be attributed to intrahepatic bile duct contamination, increased operation time, and histological liver steatosis.

Sarcomatoid hepatocellular carcinoma is distinct from ordinary hepatocellular carcinoma: Clinicopathologic, transcriptomic and immunologic analyses

Sarcomatoid hepatocellular carcinoma (SHCC), which was a rare histological subtype of hepatocellular carcinoma (HCC), is currently subclassified as poorly differentiated HCC because of insufficient evidence to define SHCC as a subtype of HCC. We aimed to assess the feasibility of classifying SHCC as a histological subtype of HCC by comprehensively identifying novel and distinct characteristics of SHCC compared to ordinary HCC (OHCC). Fifteen SHCCs (1.4%) defined as HCC with at least a 10% sarcomatous component, 15 randomly disease-stage-matched OHCCs and 163 consecutive OHCCs were extracted from 1106 HCCs in the Pathology Database (1997-2019) of our hospital. SHCC patients showed poor prognosis, and the tumors could be histologically subclassified into the pleomorphic, spindle and giant cell types according to the subtype of carcinomas with sarcomatoid or undifferentiated morphology in other organs. The transcriptomic analysis revealed distinct characteristics of SHCC featuring the upregulation of genes associated with epithelial-to-mesenchymal transition and inflammatory responses. The fluorescent multiplex immunohistochemistry results revealed prominent programmed death-ligand 1 (PD-L1) expression on sarcomatoid tumor cells and higher infiltration of CD4⁺ and CD8⁺ T cells in SHCCs compared to OHCCs. The density of CD8⁺ T cells in the nonsarcomatous component of SHCCs was also higher than that in OHCCs. In conclusion, the comprehensive analyses in our study demonstrated that SHCC is distinct from OHCC in terms of clinicopathologic, transcriptomic and immunologic characteristics. Therefore, it is reasonable to consider SHCC as a histological subtype of HCC.

Glissonean approach for hepatic inflow control in minimally invasive anatomic liver resection: A systematic review

BACKGROUND

The Glissonean approach has been widely validated for both open and minimally invasive anatomic liver resection (MIALR). However, the possible advantages compared to the conventional hilar approach are still under debate. The aim of this systematic review was to evaluate the application of the Glissonean approach in MIALR.

METHODS

A systematic review of the literature was conducted on PubMed and Ichushi databases. Articles written in English or Japanese were included. From 2,390 English manuscripts evaluated by title and abstract, 43 were included. Additionally, 23 out of 463 Japanese manuscripts were selected. Duplicates were removed, including the most recent manuscript.

RESULTS

The Glissonean approach is reported for both major and minor MIALR. The 1st, 2nd and 3rd order divisions of both right and left portal pedicles can be reached following defined anatomical landmarks. Compared to the conventional hilar approach, the Glissonean approach is associated with shorter operative time, lower blood loss, and better peri-operative outcomes.

CONCLUSIONS

Glissonean approach is safe and feasible for MIALR with several reported advantages compared to the conventional hilar approach. Clear knowledge of Laennec's capsule anatomy is necessary and serves as a guide for the dissection. However, the best surgical approach to be performed depends on surgeon experience and patients' characteristics. Standardization of the Glissonean approach for MIALR is important.

Normalizing the Microenvironment Overcomes Vessel Compression and Resistance to Nano-immunotherapy in Breast Cancer Lung Metastasis

Nano-immunotherapy regimens have high potential to improve patient outcomes, as already demonstrated in advanced triple negative breast cancer with nanoparticle albumin-bound paclitaxel and the immune checkpoint blocker (ICB) atezolizumab. This regimen, however, does not lead to cures with median survival lasting less than two years. Thus, understanding the mechanisms of resistance to and development of strategies to enhance nano-immunotherapy in breast cancer are urgently needed. Here, in human tissue it is shown that blood vessels in breast cancer lung metastases are compressed leading to hypoxia. This pathophysiology exists in murine spontaneous models of triple negative breast cancer lung metastases, along with low levels of perfusion. Because this pathophysiology is consistent with elevated levels of solid stress, the mechanotherapeutic tranilast, which decompressed lung metastasis vessels, is administered to mice bearing metastases, thereby restoring perfusion and alleviating hypoxia. As a result, the nanomedicine Doxil causes cytotoxic effects into metastases more efficiently, stimulating anti-tumor immunity. Indeed, when combining tranilast with Doxil and ICBs, synergistic effects on efficacy, with all mice cured in one of the two ICB-insensitive tumor models investigated is resulted. These results suggest that strategies to treat breast cancer with nano-immunotherapy should also include a mechanotherapeutic to decompress vessels.

Impact of Preoperative Circulating Tumor DNA Status on Survival Outcomes After Hepatectomy for Resectable Colorectal Liver Metastases

BACKGROUND

The optimal perioperative management of patients who undergo hepatectomy for resectable colorectal liver metastases (CRLM) remains unclear due to the lack of reliable methods to stratify the risk of recurrence.

METHODS

A single-center retrospective study was performed to investigate the impact of preoperative circulating tumor DNA (ctDNA) on survival outcomes of patients who underwent initial hepatectomy for solitary resectable CRLM between January 2005 and December 2017 using the comprehensive genotyping platform Guardant360^®.

RESULTS

Of 212 patients who underwent initial hepatectomy for solitary resectable CRLM, 40 patients for whom pre-hepatectomy plasma was available underwent ctDNA analysis. Among them, 32 (80%) had at least 1 somatic alteration in their ctDNA, while the other 8 (20%) had no detectable ctDNA. Among the patients with undetectable ctDNA, only one had recurrence and none died during a median follow-up period of 39.0 months. The recurrence-free survival was significantly shorter in patients who were positive for ctDNA than in those who were negative for ctDNA [median, 12.5 months vs not reached (NR); HR, 7.6; P = 0.02]. The overall survival also tended to be shorter in patients who were positive for ctDNA than those who were negative for ctDNA (median, 78.1 months vs NR; P = 0.14; HR not available).

CONCLUSIONS

In patients undergoing hepatectomy for solitary resectable CRLM, the absence of detectable preoperative ctDNA identified patients with a high chance for a cure. Risk stratification according to preoperative ctDNA analysis may be an effective tool that can improve the perioperative management of these patients.

Novel stromal biomarker screening in pancreatic cancer patients using the in vitro cancer-stromal interaction model

Background

Stromal fibroblasts associated with pancreatic ductal adenocarcinoma (PDAC) play an important role in tumor progression through interactions with cancer cells. Our proposed combination strategies of in vitro and in silico biomarker screening through a cancer-stromal interaction model were previously identified several actin-binding proteins in human colon cancer stroma. The main aim of the present study was to identify novel prognostic markers in human PDAC stroma using our strategies.

Methods

Five primary cultivated fibroblasts from human pancreas were stimulated by two types of pancreatic cancer-cell-conditioned medium (Capan-1 and MIA PaCa-2) followed by gene expression analysis to identify up-regulated genes. Publicly available microarray data set concomitant with overall survival was collected and prognostic marker candidates were selected among the genes that were found to be up-regulated. The mRNA expression levels of the selected genes were evaluated in 5 human fresh PDAC tissues. Finally, survival analysis was performed based on immunohistochemical results on tissue microarrays consisting of 216 surgically resected PDAC tissues.

Results

The microarray data of the cancer-stromal interaction model revealed that 188 probes were significantly regulated in pancreatic fibroblasts. Further, six genes were selected using publicly available microarray data set, and a single Diaphanous-related formin-3 (DIAPH3), actin-binding protein, was identified as a stromal biomarker in PDAC fibroblasts by RNA validation analysis. DIAPH3 exhibited strong immunohistochemical expression in stromal fibroblasts. The high stromal expression of DIAPH3 was associated with shorter survival times of PDAC patients.

Conclusions

DIAPH3 was identified as a prognostic marker in PDAC fibroblasts using our biomarker screening strategies through the cancer-stromal interaction model, indicating that stromal actin-binding proteins might have an important biological role in cancer progression. These strategies were also available in PDAC, and can be used for stromal biomarker screening in various cancers.

The potential application of PD-1 blockade therapy for early-stage biliary tract cancer

Biliary tract cancer (BTC) is an aggressive cancer with a poor prognosis partially due to the limited success in developing novel therapies, including molecularly targeted therapies and immunotherapies. Programmed cell death-1 (PD-1) blockade therapy is less effective against BTCs, necessitating further studies to understand the detailed immunological status of the tumor microenvironment (TME) in BTC. Here, we examined the immunological status of the TME in 37 BTCs with early- to late-stage disease, especially focusing on PD-1+CD8+ T cells. PD-1+CD8+ T cells, which are reportedly associated with the clinical response to PD-1 blockade therapy, were frequently observed in early-stage BTC and decreased with disease progression. Imaging mass cytometry for representative PD-1+CD8+TIL-high and -low patients demonstrated that tumor-infiltrating PD-1+CD8+ T cells were localized adjacent to tumor cells, whereas PD-1-CD8+ T cells were detected mainly in the stroma of the TME. In a mouse model, PD-1 expression by tumor-infiltrating CD8+ T cells was higher in smaller tumors and decreased with tumor growth. Consequently, large tumors became resistant to PD-1 blockade, while small tumors containing higher numbers of PD-1+CD8+ T cells were sensitive. We propose the important role of tumor-infiltrating PD-1+CD8+ T cells in anti-tumor immunity and the potential application of PD-1 blockade therapy for early-stage BTC.

Survival Outcomes of Resected BRAF V600E Mutant Colorectal Liver Metastases: A Multicenter Retrospective Cohort Study in Japan

BACKGROUND

Although the prognosis for patients with resected BRAF mutant colorectal liver metastases (CRLM) is poor, the survival impact of the BRAF V600E mutation in such cases remains unclear.

METHODS

A multicenter retrospective cohort study was performed to investigate the survival outcomes of patients who underwent initial hepatectomy for histologically confirmed BRAF V600E mutant CRLM between January 2005 and December 2017.

RESULTS

Thirty-three patients from 6 institutions were included in this study. During the median duration of the post-hepatectomy follow-up period of 49.2 months, 31 patients (93.9%) developed recurrence after a median period of 5.3 months and the 1-year recurrence-free survival (RFS) rate was 24.2%. Only two patients underwent repeated surgery for recurrence. The other 29 patients had unresectable recurrent lesions, and 27 of them received systemic chemotherapy. The median overall survival (OS) period was 31.1 months and the 5-year OS rate was 18.2%. The factors for a poor RFS prognosis were an elevated serum CA19-9 level (≥ 37 IU/ml) at hepatectomy (HR: 2.139, 95% CI: 1.009-4.534, P = 0.047) and R1 resection (HR: 5.827, 95% CI: 1.585-21.42, P = 0.008), and that for OS was R1 resection only (HR: 4.129, 95% CI: 1.104-15.45, P = 0.035).

CONCLUSIONS

Since the early onset unresectable recurrence rate was very high, systemic chemotherapy should be considered for resectable BRAF V600E mutant CRLM. A novel perioperative treatment strategy is needed to improve the survival of such patients.

Comparison of morphological features in lymph node metastasis between pancreatic neuroendocrine neoplasms and pancreatic ductal adenocarcinomas

BACKGROUND

Various studies have reported inconsistent results regarding the use of lymph node size for the prediction of metastasis in pancreatic cancer. Further, there is even less information in pNENs. Thus, the clinical accuracy and utility of using lymph node size to predict lymph node metastasis in pNENs has not been fully elucidated OBJECTIVES: This study aimed to examine differences in lymph node morphology between pancreatic neuroendocrine neoplasms (pNENs) and pancreatic ductal adenocarcinomas (PDACs) to create more accurate diagnostic criteria for lymph node metastasis.

METHODS

We assessed 2139 lymph nodes, 773 from pNEN specimens and 1366 from PDAC specimens, surgically resected at our institute between 1994 and 2016. We evaluated the number, shape, size, and presence of metastasis.

RESULTS

Sixty-eight lymph nodes from 16 pNEN patients and 109 lymph nodes from 33 PDAC patients were metastatic. There were more lymph nodes sampled per case in the PDAC group than in the pNEN group (31.8 vs. 18.0). Metastatic lymph nodes in pNEN patients were larger and rounder than those in PDAC patients (minor axis: 5.15 mm vs. 3.11 mm; minor axis/major axis ratio: 0.701 vs. 0.626). The correlation between lymph node size and metastasis was stronger in pNENs (r = 0.974) than in PDACs (r = 0.439).

CONCLUSIONS

Lymph node status and morphology are affected by differences in tumor histology. The lymph node minor axis is a reliable parameter for the prediction of lymph node metastasis and has more utility as a predictive marker in pNENs than in PDACs.

Peptide vaccine as an adjuvant therapy for glypican-3-positive hepatocellular carcinoma induces peptide-specific CTLs and improves long prognosis

There is no established postoperative adjuvant therapy for hepatocellular carcinoma (HCC), and improvement of patient prognosis has been limited. We conducted long‐term monitoring of patients within a phase II trial that targeted a cancer antigen, glypican‐3 (GPC3), specifically expressed in HCC. We sought to determine if the GPC3 peptide vaccine was an effective adjuvant therapy by monitoring disease‐free survival and overall survival. We also tracked GPC3 immunohistochemical (IHC) staining, CTL induction, and postoperative plasma GPC3 for a patient group that was administered the vaccine (n = 35) and an unvaccinated patient group that underwent surgery only (n = 33). The 1‐y recurrence rate after surgery was reduced by approximately 15%, and the 5‐y and 8‐y survival rates were improved by approximately 10% and 30%, respectively, in the vaccinated group compared with the unvaccinated group. Patients who were positive for GPC3 IHC staining were more likely to have induced CTLs, and 60% survived beyond 5 y. Vaccine efficacy had a positive relationship with plasma concentration of GPC3; high concentrations increased the 5‐y survival rate to 75%. We thus expect GPC3 vaccination in patients with HCC, who are positive for GPC3 IHC staining and/or plasma GPC3 to induce CTL and have significantly improved long‐term prognosis.

Clinical impact of radiofrequency ablation and stereotactic body radiation therapy for colorectal liver metastasis as local therapies for elderly, vulnerable patients

Background and Aim

Surgical resection is the standard local therapy for patients with colorectal liver metastases (CRLM). However, elderly and vulnerable patients sometimes have various organ dysfunctions. We have to conduct nonsurgical local therapies for those patients who might not tolerate surgery or systemic chemotherapy.

Methods

We retrospectively reviewed medical records of 254 patients who underwent local therapies, including surgery, radiofrequency ablation (RFA), and stereotactic body radiation therapy (SBRT), for CRLM from January 2010 to December 2016, at seven tertiary‐care institutions in Japan. This study was designed to include elderly, vulnerable patients who received local therapy for CRLM. For those undergoing liver resection, only those having one or more points of the Charlson comorbidity index (CCI) were enrolled.

Results

Of the total 169 enrolled patients, 122 patients underwent surgery, 42 RFA, and 5 SBRT as the first local therapy for CRLM. Median overall survival from the first local therapy was 5.9 years for the surgery group, 2.7 years for the RFA group, and 3.8 years for the SBRT group. The proportion of the patients with CCI ≧3 was significantly higher in the group of RFA/SBRT than surgery (P < 0.0001). In selected patients with CCI ≧3, there was no difference of the median survival time between the surgery group and the RFA group.

Conclusions

We could have other treatment options to provide nonsurgical local therapies (RFA/SBRT) for elderly, vulnerable CRLM patients who have risks for surgery.

Usefulness of plasma full-length glypican-3 as a predictive marker of hepatocellular carcinoma recurrence after radial surgery

Predicting the risk of hepatocellular carcinoma (HCC) recurrence before treatment is necessary for developing subsequent treatment policies. Several tumor markers found in blood, such as alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II), are presently used to determine the occurrence and recurrence of HCC and to predict patient prognosis. However, these markers are insufficient for these purposes as certain patients have HCC recurrence despite exhibiting negative AFP and PIVKA-II. The present study identified glypican-3 (GPC3), an embryonal carcinoma antigen that is expressed specifically in HCC and is secreted into blood. Although the N-terminal domain of GPC3 in sera may be a potential prognostic factor for HCC, its biological role remains unclear. By contrast, full-length GPC3 (FL-GPC3) is reported to serve important roles in cell differentiation, proliferation and signaling events that cause HCC. Given the biological roles of FL-GPC3 in HCC progression, the present study evaluated its potential as a predictive marker of HCC recurrence. In the present study, a novel measurement system was constructed to specifically measure plasma FL-GPC3. Subsequently, its ability to predict recurrence after radical surgery in 39 HCC patients was evaluated. The results revealed that preoperative FL-GPC3 levels in patients with recurrence were significantly higher than those in patients without recurrence, suggesting that FL-GPC3 could be a better predictive maker of risk of recurrence than AFP or PIVKA-II. Furthermore, it was determined that the combination of FL-GPC3, AFP and PIVKA-II could predict recurrence within one year of radical surgery with high sensitivity and specificity. Based on these results, the validation of FL-GPC3 as a predictive marker of HCC recurrence in a larger population is warranted.

Plasma and tumoral glypican-3 levels are correlated in patients with hepatitis C virus-related hepatocellular carcinoma

Glypican-3 (GPC3) is a cancer antigen expressed in approximately 80% of hepatocellular carcinomas (HCC) and is secreted into the blood. To confirm the effectiveness of GPC3 as a biomarker in HCC, we analyzed the relationship between GPC3 expression levels in cancer cells and in blood in 56 patients with HCC. Preoperative plasma GPC3 levels were determined with an immunoassay, and expression of GPC3 in resected tumors was analyzed by immunohistochemical staining. Median plasma GPC3 level in all HCC cases was 4.6 pg/mL, and tended to be higher in patients with hepatitis C virus (HCV)-related HCC (HCV group) (9.9 pg/mL) than in patients with hepatitis B virus (HBV)-related HCC (HBV group) (2.6 pg/mL) or in those without virus infection (None group) (3.0 pg/mL), suggesting that the virus type most likely influences GPC3 secretion. Median percentage of GPC3+ cells in tumors was also higher in the HCV (26.2%) and HBV (11.1%) groups than in the None group (4.2%). In the HCV group, there was a positive correlation between the two parameters (r = 0.66, P < .01). Moreover, receiver operating characteristic analysis predicted >10% GPC3+ cells in a tumor if the cut-off value was 6.8 pg/mL (sensitivity 80%, specificity 100%; area under the curve 0.875, 95% confidence interval 0.726-1) in the HCV group. Plasma concentration of GPC3 could be a predictive marker of tumoral GPC3 expression in patients with HCV-related HCC, suggesting a useful biomarker for immunotherapies targeting GPC3, although larger-scale validations are needed.

A multicenter prospective registration study on laparoscopic pancreatectomy in Japan: report on the assessment of 1,429 patients

BACKGROUND

Prospective studies are needed to understand the safety and feasibility of laparoscopic pancreatectomy. The aim of the present study was to describe laparoscopic pancreatectomy currently undertaken in Japan, using a prospective registration system.

METHODS

Patient characteristics and planned operations were registered preoperatively, and then the performed operation and outcomes were reported using an online system. Collected data were also compared between institutions based on their level of experience. This study was registered with UMIN000022836.

RESULTS

Available data were obtained from 1,429 patients at 100 Japanese institutions, including 1,197 laparoscopic distal pancreatectomies (LDPs) and 232 laparoscopic pancreatoduodenectomies (LPDs). The rates of completion for planned operations were 92% for LDP and 91% for LPD. Postoperative complication rates after LDP and LPD were 17% and 30%, and 90-day mortality rates were 0.3% and 0.4%, respectively. Shorter operation time, less blood loss, and lower incidence of pancreatic fistula were observed in institutions experienced in LDP. A higher rate of pure laparoscopic procedure and shorter operation time were noted in institutions experienced with LPD.

CONCLUSION

LDPs and LPDs are performed safely in Japan, especially in experienced institutions. Our data could support the next challenges in the field of laparoscopic pancreatectomy.

Area of residual tumor (ART) can predict prognosis after post neoadjuvant therapy resection for pancreatic ductal adenocarcinoma

An increasing number of patients with pancreatic ductal adenocarcinoma (PDAC) have undergone resection after neoadjuvant therapy (NAT). We have reported Area of Residual Tumor (ART) as a useful pathological assessment method to predict patient outcomes after post NAT resection in various cancer types. The aim of this study was to assess the prognostic performance of ART in PDAC resected after NAT. Sixty-three patients with PDAC after post NAT resection were analyzed. The viable residual tumor area was outlined and the measurement of ART was performed using morphometric software. The results were compared with those of the College of American Pathologist (CAP) regression grading. Of 63 cases, 39 (62%) patients received chemoradiation therapy and 24 (38%) received chemotherapy only. The median value of ART was 163 mm2. Large ART with 220 mm2 as the cut-off was significantly associated with lymphatic invasion, vascular invasion and perineural invasion, while CAP regression grading was not associated with any clinicopathological features. By multivariate analysis, large ART (≥220 mm2) was an independent predictor of shorter relapse free survival. Together with our previous reports, an ART-based pathological assessment may become a useful method to predict patient outcomes after post NAT resection across various cancer types.

Dexamethasone Increases Cisplatin-Loaded Nanocarrier Delivery and Efficacy in Metastatic Breast Cancer by Normalizing the Tumor Microenvironment

Dexamethasone is a glucocorticoid steroid with anti-inflammatory properties used to treat many diseases, including cancer, in which it helps manage various side effects of chemo-, radio-, and immunotherapies. Here, we investigate the tumor microenvironment (TME)-normalizing effects of dexamethasone in metastatic murine breast cancer (BC). Dexamethasone normalizes vessels and the extracellular matrix, thereby reducing interstitial fluid pressure, tissue stiffness, and solid stress. In turn, the penetration of 13 and 32 nm dextrans, which represent nanocarriers (NCs), is increased. A mechanistic model of fluid and macromolecule transport in tumors predicts that dexamethasone increases NC penetration by increasing interstitial hydraulic conductivity without significantly reducing the effective pore diameter of the vessel wall. Also, dexamethasone increases the tumor accumulation and efficacy of ∼30 nm polymeric micelles containing cisplatin (CDDP/m) against murine models of primary BC and spontaneous BC lung metastasis, which also feature a TME with abnormal mechanical properties. These results suggest that pretreatment with dexamethasone before NC administration could increase efficacy against primary tumors and metastases.

Preliminary Kidney Parenchymal Ligation Using Endoloop Ligatures-A Simple Method to Achieve a Trifecta in Laparoscopic Partial Nephrectomy Without Hilar Clamping for Polar Complex Tumors

OBJECTIVE

To describe a novel and simple technique of preliminary kidney parenchymal ligation using Endoloop ligatures during laparoscopic partial nephrectomy (PN) without hilar clamping for polar complex tumor cases.

METHODS

The subjects were 17 patients who had a renal mass with a R.E.N.A.L. nephrometry score ≥7 (7/8/9/10 in 3/6/6/2 patients, respectively) located in the pole of the kidney. Patient-specific 3D reconstructed kidney images were created for preoperative planning in all cases. The renal hilar vessels were meticulously dissected and definitive tumor feeders were sacrificed when the branches directly perfused the peri-tumor area. Following the vascular microdissection, a circumferential cortex-depth incision on the kidney was made all around the tumor. Consequently, several Endoloop ligatures were placed in the incised tumor base to ligate the parenchyma preliminarily. Step-by-step Endoloop tightening facilitated effective parenchymal dissection without the urinary tract. After confirming that the tumor base parenchyma was ligated sufficiently, tumor resection was completed. Neither inner- nor outer-layer renorrhaphy sutures were placed.

RESULTS

Perioperative outcomes were satisfactory and all patients had negative surgical margins with no damage in the tumor capsule. Urological complications and renal function lower than predicted at 3 months after surgery involved 1 and 3 cases, respectively. The rate of PN trifecta achievement was 82% (14/17) despite the complexity of the 17 tumors.

CONCLUSION

The current technique helped surgeons achieve the trifecta in patients with polar complex masses treated with laparoscopic PN. Use of this technique can provide surgeons with a bloodless operative field even during PN without hilar clamping.