Published papers

Background Identifying liver ischemia is crucial in liver surgery. This study aimed to develop a hemi-hepatic ischemia model for assessing liver ischemia using single snapshot imaging of optical properties (SSOP), a noninvasive optical imaging modality that provides real-time measurements of tissue oxygen saturation (StO2). Materials and methods Twelve swine were randomly assigned to two groups: One undergoing total vascular inflow occlusion (TVIO) and the other undergoing hepatic artery occlusion (HAO). Preoperative 3D CT scans were used to locate the left-sided hepatic arteries and portal veins, which were clamped during surgery. Real-time SSOP imaging was conducted to measure StO2 in three lobes—the left lateral lobe (LL), left medial lobe (LM), and right medial lobe (RM)—as well as capillary lactate levels and Doppler blood flow. Measurements were recorded at baseline (T0), during ischemia (T1, 30 min after clamping), and during reperfusion (T2, 30 min after declamping). Results In the TVIO group, SSOP imaging revealed a distinct demarcation line on the liver surface. StO2 levels measured by SSOP significantly decreased from T0 to T1, dropping by 29.8% in the LL (46.0 ± 5.1 vs. 16.2 ± 5.1%, p = 0.011) and 36.3% in the LM (42.7 ± 5.9 vs. 6.4 ± 4.0%, p = 0.001). Additionally, capillary lactate levels increased substantially in the LL (1.3 ± 0.4 vs. 8.5 ± 2.4 mmol/L, p = 0.041) and in the LM (1.3 ± 0.4 vs. 8.2 ± 2.1 mmol/L, p = 0.021). In contrast, the HAO group showed a less pronounced reduction in StO2: 13.6% in the LL (32.7 ± 6.4 vs. 19.1 ± 5.4%, p = 0.007) and 19.8% in the LM (35.3 ± 8.2 vs. 15.5 ± 5.8%, p = 0.011), with no significant increase in capillary lactate levels. An inverse correlation was found between StO2 and capillary lactate levels (r = − 0.76, p < 0.001). Conclusion SSOP is a real-time, contrast-free imaging technique that effectively evaluates liver ischemia by accurately measuring tissue oxygenation, as validated by perfusion biomarkers.

Background Identifying liver ischemia is crucial in liver surgery. This study aimed to develop a hemi-hepatic ischemia model for assessing liver ischemia using single snapshot imaging of optical properties (SSOP), a noninvasive optical imaging modality that provides real-time measurements of tissue oxygen saturation (StO2). Materials and methods Twelve swine were randomly assigned to two groups: One undergoing total vascular inflow occlusion (TVIO) and the other undergoing hepatic artery occlusion (HAO). Preoperative 3D CT scans were used to locate the left-sided hepatic arteries and portal veins, which were clamped during surgery. Real-time SSOP imaging was conducted to measure StO2 in three lobes—the left lateral lobe (LL), left medial lobe (LM), and right medial lobe (RM)—as well as capillary lactate levels and Doppler blood flow. Measurements were recorded at baseline (T0), during ischemia (T1, 30 min after clamping), and during reperfusion (T2, 30 min after declamping). Results In the TVIO group, SSOP imaging revealed a distinct demarcation line on the liver surface. StO2 levels measured by SSOP significantly decreased from T0 to T1, dropping by 29.8% in the LL (46.0 ± 5.1 vs. 16.2 ± 5.1%, p = 0.011) and 36.3% in the LM (42.7 ± 5.9 vs. 6.4 ± 4.0%, p = 0.001). Additionally, capillary lactate levels increased substantially in the LL (1.3 ± 0.4 vs. 8.5 ± 2.4 mmol/L, p = 0.041) and in the LM (1.3 ± 0.4 vs. 8.2 ± 2.1 mmol/L, p = 0.021). In contrast, the HAO group showed a less pronounced reduction in StO2: 13.6% in the LL (32.7 ± 6.4 vs. 19.1 ± 5.4%, p = 0.007) and 19.8% in the LM (35.3 ± 8.2 vs. 15.5 ± 5.8%, p = 0.011), with no significant increase in capillary lactate levels. An inverse correlation was found between StO2 and capillary lactate levels (r = − 0.76, p < 0.001). Conclusion SSOP is a real-time, contrast-free imaging technique that effectively evaluates liver ischemia by accurately measuring tissue oxygenation, as validated by perfusion biomarkers.

The REDISCOVER guidelines present 34 recommendations for the selection and perioperative care of borderline-resectable (BR-PDAC) and locally advanced ductal adenocarcinoma of the pancreas (LA-PDAC). These guidelines represent a significant shift from previous approaches, prioritizing tumor biology over anatomical features as the primary indication for resection. Condensed herein, they provide a practical management algorithm for clinical practice. However, the guidelines also highlight the need to redefine LA-PDAC to align with modern treatment strategies and to solve some contradictions within the current definition, such as grouping "difficult" and "impossible" to resect tumors together. Furthermore, the REDISCOVER guidelines highlight several areas requiring urgent research. These include the resection of the superior mesenteric artery, the management strategies for patients with LA-PDAC who are fit for surgery but unable to receive multi-agent neoadjuvant chemotherapy, the approach to patients with LA-PDAC who are fit for surgery but demonstrate high serum Ca 19.9 levels even after neoadjuvant treatment, and the optimal timing and number of chemotherapy cycles prior to surgery. Additionally, the role of primary chemoradiotherapy versus chemotherapy alone in LA-PDAC, the timing of surgical resection post-neoadjuvant/primary chemoradiotherapy, the efficacy of ablation therapies, and the management of oligometastasis in patients with LA-PDAC warrant investigation. Given the limited evidence for many issues, refining existing management strategies is imperative. The establishment of the REDISCOVER registry (https://rediscover.unipi.it/) offers promise of a unified research platform to advance understanding and improve the management of BR-PDAC and LA-PDAC.

Objective: The REDISCOVER consensus conference aimed at developing and validating guidelines on the perioperative care of patients with borderline-resectable (BR-) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC). Background: Coupled with improvements in chemotherapy and radiation, the contemporary approach to pancreatic surgery supports the resection of BR-PDAC and, to a lesser extent, LA-PDAC. Guidelines outlining the selection and perioperative care for these patients are lacking. Methods: The Scottish Intercollegiate Guidelines Network (SIGN) methodology was used to develop the REDISCOVER guidelines and create recommendations. The Delphi approach was used to reach a consensus (agreement ≥80%) among experts. Recommendations were approved after a debate and vote among international experts in pancreatic surgery and pancreatic cancer management. A Validation Committee used the AGREE II-GRS tool to assess the methodological quality of the guidelines. Moreover, an independent multidisciplinary advisory group revised the statements to ensure adherence to nonsurgical guidelines. Results: Overall, 34 recommendations were created targeting centralization, training, staging, patient selection for surgery, possibility of surgery in uncommon scenarios, timing of surgery, avoidance of vascular reconstruction, details of vascular resection/reconstruction, arterial divestment, frozen section histology of perivascular tissue, extent of lymphadenectomy, anticoagulation prophylaxis, and role of minimally invasive surgery. The level of evidence was however low for 29 of 34 clinical questions. Participants agreed that the most conducive means to promptly advance our understanding in this field is to establish an international registry addressing this patient population (https://rediscover.unipi.it/). Conclusions: The REDISCOVER guidelines provide clinical recommendations pertaining to pancreatectomy with vascular resection for patients with BR-PDAC and LA-PDAC, and serve as the basis of a new international registry for this patient population.

Background: Robotic pancreaticoduodenectomy (RPD) has emerged as a promising surgical approach for the treatment of periampullary neoplasms, offering the potential benefits of minimally invasive surgery. However, the impact of RPD on clinically relevant pancreatic fistula (CR-PF) rates and overall costs compared to open pancreaticoduodenectomy (OPD) remains unclear, limiting its widespread adoption. Methods: This retrospective cohort study was conducted at a high-volume Japanese referral center from 2017 to 2023. A total of 193 patients diagnosed with periampullary neoplasms underwent either RPD (n = 81) or OPD (n = 112). To account for potential selection bias, propensity score matching (PSM) was used to balance patient demographics and clinical characteristics, resulting in two well-matched groups of 60 patients each. Perioperative outcomes, CR-PF rates, and a comprehensive cost analysis were evaluated. Results: RPD resulted in a significantly lower rate of CR-PF (10%) compared to OPD (33.3%) (p = 0.003). Additionally, patients who underwent RPD experienced shorter hospital stays (15 days) compared to those in the OPD group (22.5 days) (p < 0.001). Despite longer operative times for RPD (633 vs. 395 min; p < 0.001), total hospital costs were comparable between the two groups. The higher operative costs associated with RPD were offset by reduced postoperative complications and shorter hospitalization. Conclusions: RPD offers significant clinical advantages, including lower CR-PF rates and reduced hospital stays, without increasing overall hospital costs compared to OPD. These findings support the feasibility and potential benefits of adopting RPD for the management of periampullary neoplasms in clinical practice.

Anatomical resection (AR) has been reported to achieve better long-term outcomes than non-anatomical resection for the treatment of hepatocellular carcinoma (HCC). The surgical feasibility and oncological significance of laparoscopic AR (LAR), especially “subsegment resection”, “cone unit resection”, and repeat LAR for HCC, remain unproven. We present a 67-year-old patient with alcoholic liver cirrhosis and HCC who underwent full LAR three times, focusing on the technical aspects of the Glissonean approach. Repeating LAR for recurrent HCC could be a safe and feasible procedure. However, HCC recurred in the neighboring segment twice, even though pathological vascular invasion and marginal remnants were not confirmed. We should investigate the oncological significance and advancements in subsegmentectomy and cone unit resection, in the future.

Introduction: Laparoscopic liver resection (LLr) has made remarkable progress over the past two decades, provid-ing superior perioperative outcomes to open liver resection (OLr). The pros and cons of LLr for colorectal liver metas-tases (CrLMs) have been discussed along with the debate regarding optimal resection margins for CrLMs. eviDenCe aCQuiSiTiOn: a literature review has been carried out (Pubmed and embase) focusing on the resection margin status (r status) after LLr for CrLMs. eviDenCe SynTHeSiS: LLr for CrLMs results in r1 in 7.6 to 21.3% of cases, the risk being the size and number of tumors and the amount of intraoperative blood loss. r1 is associated with shorter recurrence-free survival but has no impact on overall survival. There is insufficient evidence regarding the prognostic value of laparoscopic two-stage hepa-tectomy (TSH) or repeat hepatectomy (rH) for CrLMs. COnCLuSiOnS: although r0 remains the golden standard for CrLMs, the acceptability of r1 should be determined based on an overall assessment of the biological malignancy, remnant liver volume, and the proximity to major vascu-lature. The strategy of performing multiple LLrs for CrLMs while allowing for r1 at the initial operation is a topic for future research.

Introduction: Despite the advances in minimally invasive (MI) liver surgery, most major hepatectomies (MHs) continue to be performed by open surgery. This study aimed to evaluate the risk factors and outcomes of open conversion during MI MH, including the impact of the type of approach (laparoscopic vs. robotic) on the occurrence and outcomes of conversions. Methods: Data on 3880 MI conventional and technical (right anterior and posterior sectionectomies) MHs were retrospectively collected. Risk factors and perioperative outcomes of open conversion were analyzed. Multivariate analysis, propensity score matching, and inverse probability treatment weighting analysis were performed to control for confounding factors. Results: Overall, 3211 laparoscopic MHs (LMHs) and 669 robotic MHs (RMHs) were included, of which 399 (10.28%) had an open conversion. Multivariate analyses demonstrated that male sex, laparoscopic approach, cirrhosis, previous abdominal surgery, concomitant other surgery, American Society of Anesthesiologists (ASA) score 3/4, larger tumor size, conventional MH, and Institut Mutualiste Montsouris classification III procedures were associated with an increased risk of conversion. After matching, patients requiring open conversion had poorer outcomes compared with non-converted cases, as evidenced by the increased operation time, blood transfusion rate, blood loss, hospital stay, postoperative morbidity/major morbidity and 30/90-day mortality. Although RMH showed a decreased risk of conversion compared with LMH, converted RMH showed increased blood loss, blood transfusion rate, postoperative major morbidity and 30/90-day mortality compared with converted LMH. Conclusions: Multiple risk factors are associated with conversion. Converted cases, especially those due to intraoperative bleeding, have unfavorable outcomes. Robotic assistance seemed to increase the feasibility of the MI approach, but converted robotic procedures showed inferior outcomes compared with converted laparoscopic procedures.

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

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

Background: To evaluate the utility of robotassisted laparoscopic transabdominal preperitoneal repair (R-TAPP) of postprostatectomy inguinal hernia (PIH) in patients who underwent robot-assisted laparoscopic radical prostatectomy (RALP). Patients and Methods: This was a prospective, single-centre retrospective cohort study. R-TAPP was conducted in 74 consecutive patients from September 2016 to March 2020. With the exception of women and patients who underwent previous abdominal surgery, 70 patients were classified into two groups based on the absence or presence of PIH. Their data were retrospectively compared to those who had not undergone RALP. Results: The median operative time for the PIH group was longer compared to the non-PIH group. However, postoperative complications, including seroma formation, haematoma and surgical site infections, were not significantly different between the groups. The estimated blood loss was small, and hospitalisation duration was 1 day in all cases. Moreover, there were no hernia recurrences within the 90-day followup period in either group. Conclusion: R-TAPP is a feasible and safe approach for inguinal hernia repair, even in patients who undergo RALP for prostate cancer.

Introduction: The Iwate Score (IS) have not been well-validated for specific procedures, especially for right posterior sectionectomy (RPS). In this study, the utility of the IS was determined for laparoscopic (L)RPS and the effect of tumor location on surgical outcomes was investigated. Methods: Post-hoc analysis of 647 L-RPS performed in 40 international centers of which 596L-RPS cases met the inclusion criteria. Baseline characteristics and perioperative outcomes of patients stratified based on the Iwate score were compared to determine whether a correlation with surgical difficulty existed. A 1:1 Mahalanobis distance matching was utilized to investigate the effect of tumor location on L-RPS outcomes. Results: The patients were stratified into 3 levels of difficulty (31 intermediate, 143 advanced, and 422 expert) based on the IS. When using a stepwise increase of the IS excluding the tumor location score, only Pringle’s maneuver was more frequently used in the higher surgical difficulty level (35.5%, 54.6%, and 65.2%, intermediate, advanced, and expert levels, respectively, Z = 3.34, p = 0.001). Other perioperative results were not associated with a statistical gradation toward higher difficulty level. 80 of 85 patients with a segment VI lesion and 511 patients with a segment VII lesion were matched 1:1. There were no significant differences in the perioperative outcomes of the two groups including open conversion, operating time, blood loss, intraoperative blood transfusion, postoperative stay, major morbidity, and mortality. Conclusion: Among patients undergoing L-RPS, the IS did not significantly correlate with most outcome measures associated with intraoperative difficulty and postoperative outcomes. Similarly, tumor location had no effect on L-RPS outcomes.

Introduction: The Iwate difficulty scoring system (DSS) is one of the most widely validated DSS for laparoscopic liver resection (LLR). However, these studies only validated the 4 difficulty levels and did not validate the 12-point difficulty index of the system. To address current limitations in the studies validating the Iwate difficulty scoring system (DSS), we performed an international multicenter study to validate the Iwate DSS across both its four difficulty levels and 12-point difficulty index. Methods: A retrospective cohort study of 22,252 patients undergoing LLR across 64 centers worldwide between 2005 and 2021 was performed. Baseline characteristics and perioperative outcomes were analyzed across the four difficulty levels and 12-point difficulty index of the Iwate DSS. Results: A total of 14,759 patients met the inclusion criteria. The main indications for LLR were hepatocellular carcinoma/intrahepatic cholangiocarcinoma (52.8 %), and metastatic tumors liver (26.5 %). In terms of underlying liver pathology, 5127 patients (34.8 %) had liver cirrhosis, and 1214 patients (8.3 %) had portal hypertension. Intraoperative outcomes (operation time, blood loss, blood transfusion, use of Pringles maneuver and open conversion) and postoperative outcomes (length of stay, morbidity, major complications, and 90-day mortality) significantly increased with stepwise increases across the four difficulty levels (P < 0.001) and 12-point difficulty index (P < 0.001). These trends remained significant following adjustment for baseline characteristics (P < 0.001). Conclusion: The Iwate DSS 12-point difficulty index and four difficulty levels correlated well with LLR difficulty as determined by key surrogate perioperative measures.

A 73-year-old man was admitted to our hospital with abdominal pain and distension. Abdominal contrast-enhanced computed tomography (CT) showed intestinal intussusception from the cecum to the ascending colon. CT revealed terminal ileum intussusception. After endoscopic repositioning, laparoscopic ileocecal resection was performed. Pathological findings showed intestinal intussusception caused by small intestinal leiomyosarcoma. The postoperative CS revealed an elevated lesion, which was treated by endoscopic mucosal resection. Pathologically, colonic leiomyoma was identified. We report this case since it is rare for both small intestinal leiomyosarcoma and colorectal leiomyoma to occur concurrently.

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

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver and the third leading cause of cancer-related deaths worldwide. Liver resection has been widely accepted as the mainstay of HCC treatment, leading to long-term survival in well-selected patients. Over the last two decades, laparoscopic liver resection (LLR) has developed worldwide parallel to technological advancements and increased experience of liver surgeons. Several meta-analyses revealed that LLR for HCC has yielded better short-term outcomes without compromising long-term outcomes, compared to open liver resection (OLR). During treatment of HCC patients with chronic liver disease or liver cirrhosis, LLR decreases blood loss and postoperative complications including refractory ascites, leading to a shorter hospital stay. In the treatment of recurrent HCC, LLR makes subsequent procedures easier by minimizing adhesion formation. The procedure of laparoscopic major liver resection (major LLR) is yet to be standardized and is still in exploration stage according to the Morioka international conference, 2014. Laparoscopic parenchyma-sparing anatomical liver resection (Lap-PSAR) is a novel surgical strategy to resect all malignant tissues while preserving enough liver parenchyma to prevent postoperative liver failure. In conclusion, LLR has many advantages for the treatment of HCC patients and generally results in better short-term outcomes. Further investigations are needed to standardize the procedures of major LLR and Lap-PSAR.

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

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

Introduction Knowledge of the clinical liver anatomy has evolved with advanced imaging modalities and laparoscopic surgery. Therefore, precise anatomical resection knowledge has become the standard treatment for primary and secondary liver cancer. Segmentectomy, a parenchymal-preserving approach, is regarded as an option for anatomical resections in patients with impaired liver. Indocyanine green (ICG) staining is a promising method for understanding the anatomical borders of the liver segments. There are two methods of ICG staining (positive and negative), and the superiority of either approach has not been determined to date. Methods and analysis This is a prospective randomised controlled superiority clinical trial performed in a single centre tertiary hospital in Japan. A comparison between the accuracy of positive and negative ICG staining in guiding laparoscopic anatomical liver resection is planned in this study. Possible candidates are patients with liver malignant tumours in whom laparoscopic monosegmentectomy or subsegmentectomy is planned. Fifty patients will be prospectively allocated into the following two groups: group A, ICG-negative staining group, and group B, ICG-positive staining group. The optimal dose of ICG for positive staining will be determined during the preparation phase. To assess the ability of the ICG fluorescence guidance in anatomical resection, the primary endpoint is the success rate of ICG staining, which consists of a SOS based on three components: superficial demarcation in the liver surface, visualisation of the parenchymal borders and consistency with the preoperative three-dimensional simulation. The secondary endpoints are the evaluation of short-term surgical outcomes and recurrence-free survival. Ethics and dissemination The study was approved by Ageo Central General Hospital Clinical Research Ethical Committee (No: 1044) and it carried out following the Declaration of Helsinki (2013 revision). Informed consent will be taken from the patients before participating. The findings will be disseminated through peer-reviewed publications, scientific meetings and conferences. Trial registration number UMIN000049815.

Background: Presently, according to different difficulty scoring systems, there is no difference in complexity estimation of laparoscopic liver resection (LLR) of segments 7 and 8. However, there is no published data supporting this assumption. To date, no studies have compared the outcomes of laparoscopic parenchyma-sparing resection of the liver segments 7 and 8. Methods: A post hoc analysis of patients undergoing LLR of segments 7 and 8 in 46 centers between 2004 and 2020 was performed. 1:1 Propensity score matching (PSM) was used to compare isolated LLR of segments 7 and 8. Subset analyses were also performed to compare atypical resections and segmentectomies of 7 and 8. Results: A total of 2411 patients were identified, and 1691 patients met the inclusion criteria. Comparison after PSM between the entire cohort of segment 7 and segment 8 resections revealed inferior results for segment 7 resection in terms of increased blood loss, blood transfusions, and conversions to open surgery. Subset analyses of only atypical resections similarly demonstrated poorer outcomes for segment 7 in terms of increased blood loss, operation time, blood transfusions, and conversions to open surgery. Conversely, a subgroup analysis of segmentectomies after PSM found better outcomes for segment 7 in terms of a shorter operation time and hospital stay. Conclusion: Differences in the outcomes of segments 7 and 8 resections suggest a greater difficulty of laparoscopic atypical resection of segment 7 compared to segment 8, and greater difficulty of segmentectomy 8 compared to segmentectomy 7.