Laparoscopic Versus Open Hemihepatectomy: The ORANGE II PLUS Multicenter Randomized Controlled Trial.

PURPOSE: To compare outcomes after laparoscopic versus open major liver resection (hemihepatectomy) mainly for primary or metastatic cancer. The primary outcome measure was time to functional recovery. Secondary outcomes included morbidity, quality of life (QoL), and for those with cancer, resection margin status and time to adjuvant systemic therapy. PATIENTS AND METHODS: This was a multicenter, randomized controlled, patient-blinded, superiority trial on adult patients undergoing hemihepatectomy. Patients were recruited from 16 hospitals in Europe between November 2013 and December 2018. RESULTS: Of the 352 randomly assigned patients, 332 patients (94.3%) underwent surgery (laparoscopic, n = 166 and open, n = 166) and comprised the analysis population. The median time to functional recovery was 4 days (IQR, 3-5; range, 1-30) for laparoscopic hemihepatectomy versus 5 days (IQR, 4-6; range, 1-33) for open hemihepatectomy (difference, -17.5% [96% CI, -25.6 to -8.4]; P < .001). There was no difference in major complications (laparoscopic 24/166 [14.5%] v open 28/166 [16.9%]; odds ratio [OR], 0.84; P = .58). Regarding QoL, both global health status (difference, 3.2 points; P < .001) and body image (difference, 0.9 points; P < .001) scored significantly higher in the laparoscopic group. For the 281 (84.6%) patients with cancer, R0 resection margin status was similar (laparoscopic 106 [77.9%] v open 122 patients [84.1%], OR, 0.60; P = .14) with a shorter time to adjuvant systemic therapy in the laparoscopic group (46.5 days v 62.8 days, hazard ratio, 2.20; P = .009). CONCLUSION: Among patients undergoing hemihepatectomy, the laparoscopic approach resulted in a shorter time to functional recovery compared with open surgery. In addition, it was associated with a better QoL, and in patients with cancer, a shorter time to adjuvant systemic therapy with no adverse impact on cancer outcomes observed.

Robotic Versus Laparoscopic Liver Resection in Various Settings: An International Multicenter Propensity Score Matched Study of 10.075 Patients.

OBJECTIVE: To compare the perioperative outcomes of robotic liver surgery (RLS) and laparoscopic liver surgery (LLS) in various settings. BACKGROUND: Clear advantages of RLS over LLS have rarely been demonstrated, and the associated costs of robotic surgery are generally higher than those of laparoscopic surgery. Therefore, the exact role of the robotic approach in minimally invasive liver surgery remains to be defined. METHODS: In this international retrospective cohort study, the outcomes of patients who underwent RLS and LLS for all indications between 2009 and 2021 in 34 hepatobiliary referral centers were compared. Subgroup analyses were performed to compare both approaches across several types of procedures: (1) minor resections in the anterolateral (2, 3, 4b, 5, and 6) or (2) posterosuperior segments (1, 4a, 7, 8), and (3) major resections (≥3 contiguous segments). Propensity score matching was used to mitigate the influence of selection bias. The primary outcome was textbook outcome in liver surgery (TOLS), previously defined as the absence of intraoperative incidents ≥grade 2, postoperative bile leak ≥grade B, severe morbidity, readmission, and 90-day or in-hospital mortality with the presence of an R0 resection margin in case of malignancy. The absence of a prolonged length of stay was added to define TOLS+. RESULTS: Among the 10.075 included patients, 1.507 underwent RLS and 8.568 LLS. After propensity score matching, both groups constituted 1.505 patients. RLS was associated with higher rates of TOLS (78.3% vs 71.8%, P < 0.001) and TOLS+ (55% vs 50.4%, P = 0.026), less Pringle usage (39.1% vs 47.1%, P < 0.001), blood loss (100 vs 200 milliliters, P < 0.001), transfusions (4.9% vs 7.9%, P = 0.003), conversions (2.7% vs 8.8%, P < 0.001), overall morbidity (19.3% vs 25.7%, P < 0.001), and microscopically irradical resection margins (10.1% vs. 13.8%, P = 0.015), and shorter operative times (190 vs 210 minutes, P = 0.015). In the subgroups, RLS tended to have higher TOLS rates, compared with LLS, for minor resections in the posterosuperior segments (n = 431 per group, 75.9% vs 71.2%, P = 0.184) and major resections (n = 321 per group, 72.9% vs 67.5%, P = 0.086), although these differences did not reach statistical significance. CONCLUSIONS: While both produce excellent outcomes, RLS might facilitate slightly higher TOLS rates than LLS.

Deep learning-assisted survival prognosis in renal cancer: A CT scan-based personalized approach.

This paper presents a deep learning (DL) approach for predicting survival probabilities of renal cancer patients based solely on preoperative CT imaging. The proposed approach consists of two networks: a classifier- and a survival- network. The classifier attempts to extract features from 3D CT scans to predict the ISUP grade of Renal cell carcinoma (RCC) tumors, as defined by the International Society of Urological Pathology (ISUP). Our classifier is a 3D convolutional neural network to avoid losing crucial information on the interconnection of slides in 3D images. We employ multiple procedures, including image augmentation, preprocessing, and concatenation, to improve the performance of the classifier. Given the strong correlation between ISUP grading and renal cancer prognosis in the clinical context, we use the ISUP grading features extracted by the classifier as the input to the survival network. By leveraging this clinical association and the classifier network, we are able to model our survival analysis using a simple DL-based network. We adopt a discrete LogisticHazard-based loss to extract intrinsic survival characteristics of RCC tumors from CT images. This allows us to build a completely parametric survival model that varies with patients' tumor characteristics and predicts non-proportional survival probability curves for different patients. Our results demonstrated that the proposed method could predict the future course of renal cancer with reasonable accuracy from the CT scans. The proposed method obtained an average concordance index of 0.72, an integrated Brier score of 0.15, and an area under the curve value of 0.71 on the test cohorts.

Hybrid optical-vision tracking in laparoscopy: accuracy of navigation and ultrasound reconstruction.

INTRODUCTION: The use of laparoscopic and robotic liver surgery is increasing. However, it presents challenges such as limited field of view and organ deformations. Surgeons rely on laparoscopic ultrasound (LUS) for guidance, but mentally correlating ultrasound images with pre-operative volumes can be difficult. In this direction, surgical navigation systems are being developed to assist with intra-operative understanding. One approach is performing intra-operative ultrasound 3D reconstructions. The accuracy of these reconstructions depends on tracking the LUS probe. MATERIAL AND METHODS: This study evaluates the accuracy of LUS probe tracking and ultrasound 3D reconstruction using a hybrid tracking approach. The LUS probe is tracked from laparoscope images, while an optical tracker tracks the laparoscope. The accuracy of hybrid tracking is compared to full optical tracking using a dual-modality tool. Ultrasound 3D reconstruction accuracy is assessed on an abdominal phantom with CT transformed into the optical tracker's coordinate system. RESULTS: Hybrid tracking achieves a tracking error < 2 mm within 10 cm between the laparoscope and the LUS probe. The ultrasound reconstruction accuracy is approximately 2 mm. CONCLUSION: Hybrid tracking shows promising results that can meet the required navigation accuracy for laparoscopic liver surgery.

Pan-European survey on current treatment strategies in patients with upfront resectable colorectal liver metastases.

BACKGROUND: There is a lack of consensus on the definition of upfront resectability and use of perioperative systemic therapy for colorectal liver metastases (CRLM). This survey aimed to summarize the current treatment strategies for upfront resectable CRLM throughout Europe. METHODS: A survey was sent to all members of the European-African Hepato-Pancreato-Biliary Association to gain insight into the current views on resectability and the use of systemic therapy for upfront resectable CRLM. RESULTS: The survey was completed by 87 surgeons from 24 countries. The resectability of CRLM is mostly based on the volume of the future liver remnant, while considering tumor biology. Thermal ablation was considered as an acceptable adjunct to resection in parenchymal-sparing CRLM surgery by 77 % of the respondents. A total of 40.2 % of the respondents preferred standard perioperative systemic therapy and 24.1 % preferred standard upfront local treatment. CONCLUSION: Among the participating European hepato-pancreato-biliary surgeons, there is a high degree of consensus on the definition of CRLM resectability. However, there is much variety in the use of adjunctive thermal ablation. Major variations persist in the use of perioperative systemic therapy in cases of upfront resectable CRLM, stressing the need for further evidence and a consensus.

Postoperative Hyperamylasemia (POH) is an Early Predictor of Pancreatic Fistula Occurrence and Severity after Distal Pancreatectomy: Results from a European Multicentric Study.

OBJECTIVES: The aim of this international multicentric study is to characterize postoperative hyperamylasemia (POH) after distal pancreatectomy (DP), with particular focus on its relationship with postoperative pancreatic fistula (POPF) occurrence and severity. BACKGROUND: The clinical relevance of POH after DP and its relationship with the occurrence and severity of POPF have not been explored yet. METHODS: All patients undergoing DP for any indication between 2015 and 2021 at three European referral Centers for pancreatic surgery were retrospectively analyzed. Drain fluid amylase (DFA), C-reactive protein (C-RP), and serum amylase were examined from postoperative-day (POD) 1 to 3. Biochemical leak (BL), POPF, POH, and post-pancreatectomy hemorrhage (PPH) were defined and graded according to ISGPS definitions. RESULTS: In total 1192 patients were included. Overall rates of POH and POPF were 18% (n= 210) and 29% (n= 344), respectively. The presence of DFA ≥2000 U/L on POD 1 (OR=2.11, 95% CI 1.68-2.86), C-RP ≥200 mg/L on POD 3 (OR=2.19, 95% CI 1.68-2.86), and POH (OR=1.58, 95% CI 1.14-2.19) were all independent early predictors of POPF (all P< 0.01). The presence of POH almost doubled the rate of POPF (43% vs. 26%, P<0.001), and higher POPF severity presented also higher POH rates (no POPF= 12%; BL= 19%; B POPF= 24%; C POPF= 52%). Among patients developing POPF, patients with POH had higher rates of PPH (22% vs 9%, P= 0.001), sepsis (24% vs 13%; P=0.011), re-operation (21% vs 8%; P< 0.01), and mortality (3% vs 0.3%; P= 0.025). CONCLUSIONS: The occurrence of POH is an early predictor of POPF and its severity after DP. The diagnosis of POH might define patients at higher risk for a complicated course, targeting them for prevention / mitigation strategies against pancreas specific complications.

Propensity Score-Matching Analysis Comparing Robotic Versus Laparoscopic Limited Liver Resections of the Posterosuperior Segments: An International Multicenter Study.

OBJECTIVE: The purpose of this study was to compare the outcomes of robotic limited liver resections (RLLR) versus laparoscopic limited liver resections (LLLR) of the posterosuperior segments. BACKGROUND: Both laparoscopic and robotic liver resections have been used for tumors in the posterosuperior liver segments. However, the comparative performance and safety of both approaches have not been well examined in the existing literature. METHODS: This is a post hoc analysis of a multicenter database of 5446 patients who underwent RLLR or LLLR of the posterosuperior segments (I, IVa, VII, and VIII) at 60 international centers between 2008 and 2021. Data on baseline demographics, center experience and volume, tumor features, and perioperative characteristics were collected and analyzed. Propensity score-matching (PSM) analysis (in both 1:1 and 1:2 ratios) was performed to minimize selection bias. RESULTS: A total of 3510 cases met the study criteria, of whom 3049 underwent LLLR (87%), and 461 underwent RLLR (13%). After PSM (1:1: and 1:2), RLLR was associated with a lower open conversion rate [10 of 449 (2.2%) vs 54 of 898 (6.0%); P =0.002], less blood loss [100 mL [IQR: 50-200) days vs 150 mL (IQR: 50-350); P <0.001] and a shorter operative time (188 min (IQR: 140-270) vs 222 min (IQR: 158-300); P <0.001]. These improved perioperative outcomes associated with RLLR were similarly seen in a subset analysis of patients with cirrhosis-lower open conversion rate [1 of 136 (0.7%) vs 17 of 272 (6.2%); P =0.009], less blood loss [100 mL (IQR: 48-200) vs 160 mL (IQR: 50-400); P <0.001], and shorter operative time [190 min (IQR: 141-258) vs 230 min (IQR: 160-312); P =0.003]. Postoperative outcomes in terms of readmission, morbidity and mortality were similar between RLLR and LLLR in both the overall PSM cohort and cirrhosis patient subset. CONCLUSIONS: RLLR for the posterosuperior segments was associated with superior perioperative outcomes in terms of decreased operative time, blood loss, and open conversion rate when compared with LLLR.

MRI in addition to CT in patients scheduled for local therapy of colorectal liver metastases (CAMINO): an international, multicentre, prospective, diagnostic accuracy trial.

BACKGROUND: Guidelines are inconclusive on whether contrast-enhanced MRI using gadoxetic acid and diffusion-weighted imaging should be added routinely to CT in the investigation of patients with colorectal liver metastases who are scheduled for curative liver resection or thermal ablation, or both. Although contrast-enhanced MRI is reportedly superior than contrast-enhanced CT in the detection and characterisation of colorectal liver metastases, its effect on clinical patient management is unknown. We aimed to assess the clinical effect of an additional liver contrast-enhanced MRI on local treatment plan in patients with colorectal liver metastases amenable to local treatment, based on contrast-enhanced CT. METHODS: We did an international, multicentre, prospective, incremental diagnostic accuracy trial in 14 liver surgery centres in the Netherlands, Belgium, Norway, and Italy. Participants were aged 18 years or older with histological proof of colorectal cancer, a WHO performance status score of 0-4, and primary or recurrent colorectal liver metastases, who were scheduled for local therapy based on contrast-enhanced CT. All patients had contrast-enhanced CT and liver contrast-enhanced MRI including diffusion-weighted imaging and gadoxetic acid as a contrast agent before undergoing local therapy. The primary outcome was change in the local clinical treatment plan (decided by the individual clinics) on the basis of liver contrast-enhanced MRI findings, analysed in the intention-to-image population. The minimal clinically important difference in the proportion of patients who would have change in their local treatment plan due to an additional liver contrast-enhanced MRI was 10%. This study is closed and registered in the Netherlands Trial Register, NL8039. FINDINGS: Between Dec 17, 2019, and July 31, 2021, 325 patients with colorectal liver metastases were assessed for eligibility. 298 patients were enrolled and included in the intention-to-treat population, including 177 males (59%) and 121 females (41%) with planned local therapy based on contrast-enhanced CT. A change in the local treatment plan based on liver contrast-enhanced MRI findings was observed in 92 (31%; 95% CI 26-36) of 298 patients. Changes were made for 40 patients (13%) requiring more extensive local therapy, 11 patients (4%) requiring less extensive local therapy, and 34 patients (11%) in whom the indication for curative-intent local therapy was revoked, including 26 patients (9%) with too extensive disease and eight patients (3%) with benign lesions on liver contrast-enhanced MRI (confirmed by a median follow-up of 21·0 months [IQR 17·5-24·0]). INTERPRETATION: Liver contrast-enhanced MRI should be considered in all patients scheduled for local treatment for colorectal liver metastases on the basis of contrast-enhanced CT imaging. FUNDING: The Dutch Cancer Society and Bayer AG - Pharmaceuticals.

Local Tumour Control Following Microwave Ablation: Protocol for the Prospective Observational CIEMAR Study.

PURPOSE: Microwave ablation (MWA) is a treatment modality for colorectal liver metastases (CRLM). While potentially curative, more information is needed on factors that contribute to long-term local tumour control. The prospective multicentre observational study CIRSE Emprint Microwave Ablation Registry aims to prospectively collect real-world technical data and clinical outcomes on patients treated with MWA in CRLM. METHODS: Eligible patients are adults with up to 9 local treatment naïve CRLM of ≤ 3 cm completely treatable with either MWA alone or MWA with resection and/or radiotherapy within 8 weeks. Data are collected, at baseline, every 3 months until 12 months, and thereafter every 6 months until the end of the study. The primary outcome measure is local tumour control. Secondary outcome measures are overall survival, (hepatic-) disease-free survival, time-to-progression untreatable by ablation, systemic therapy vacation, safety, and quality of life. Covariates related to the primary outcome measure will be assessed using a stratified log-rank test and an univariable Cox proportional hazard regression. A sample size of 500 patients with 750 lesions produces a two-sided 95% confidence interval with a precision equal to 0.057. RESULTS: Between September 2019 and December 2022, 500 patients have been enrolled with at least 976 treated tumours. CONCLUSION: The prospective observational CIEMAR study will provide valuable insights into the real-world use of MWA, helping in the future patient selection and clarifying factors that may contribute to long-term local tumour control. TRIAL REGISTRATION: NCT03775980.

The multi-societal European consensus on the terminology, diagnosis and management of patients with synchronous colorectal cancer and liver metastases: an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE.

BACKGROUND: Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases with a focus on terminology, diagnosis and management. METHODS: This project was a multi-organisational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis and management. Statements were refined during an online Delphi process and those with 70% agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising twelve key statements. RESULTS: Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term "early metachronous metastases" applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour with "late metachronous metastases" applied to those detected after 12 months. Disappearing metastases applies to lesions which are no longer detectable on MR scan after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways including systemic chemotherapy, synchronous surgery and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed. CONCLUSIONS: The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases.

Multisocietal European consensus on the terminology, diagnosis, and management of patients with synchronous colorectal cancer and liver metastases: an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE.

BACKGROUND: Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases, with a focus on terminology, diagnosis, and management. METHODS: This project was a multiorganizational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis, and management. Statements were refined during an online Delphi process, and those with 70 per cent agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising 12 key statements. RESULTS: Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term 'early metachronous metastases' applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour, the term 'late metachronous metastases' applies to those detected after 12 months. 'Disappearing metastases' applies to lesions that are no longer detectable on MRI after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards, and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways, including systemic chemotherapy, synchronous surgery, and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed. CONCLUSION: The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases.

Learning Curves of Minimally Invasive Distal Pancreatectomy in Experienced Pancreatic Centers.

Importance: Understanding the learning curve of a new complex surgical technique helps to reduce potential patient harm. Current series on the learning curve of minimally invasive distal pancreatectomy (MIDP) are mostly small, single-center series, thus providing limited data. Objective: To evaluate the length of pooled learning curves of MIDP in experienced centers. Design, Setting, and Participants: This international, multicenter, retrospective cohort study included MIDP procedures performed from January 1, 2006, through June 30, 2019, in 26 European centers from 8 countries that each performed more than 15 distal pancreatectomies annually, with an overall experience exceeding 50 MIDP procedures. Consecutive patients who underwent elective laparoscopic or robotic distal pancreatectomy for all indications were included. Data were analyzed between September 1, 2021, and May 1, 2022. Exposures: The learning curve for MIDP was estimated by pooling data from all centers. Main Outcomes and Measures: The learning curve was assessed for the primary textbook outcome (TBO), which is a composite measure that reflects optimal outcome, and for surgical mastery. Generalized additive models and a 2-piece linear model with a break point were used to estimate the learning curve length of MIDP. Case mix-expected probabilities were plotted and compared with observed outcomes to assess the association of changing case mix with outcomes. The learning curve also was assessed for the secondary outcomes of operation time, intraoperative blood loss, conversion to open rate, and postoperative pancreatic fistula grade B/C. Results: From a total of 2610 MIDP procedures, the learning curve analysis was conducted on 2041 procedures (mean [SD] patient age, 58 [15.3] years; among 2040 with reported sex, 1249 were female [61.2%] and 791 male [38.8%]). The 2-piece model showed an increase and eventually a break point for TBO at 85 procedures (95% CI, 13-157 procedures), with a plateau TBO rate at 70%. The learning-associated loss of TBO rate was estimated at 3.3%. For conversion, a break point was estimated at 40 procedures (95% CI, 11-68 procedures); for operation time, at 56 procedures (95% CI, 35-77 procedures); and for intraoperative blood loss, at 71 procedures (95% CI, 28-114 procedures). For postoperative pancreatic fistula, no break point could be estimated. Conclusion and Relevance: In experienced international centers, the learning curve length of MIDP for TBO was considerable with 85 procedures. These findings suggest that although learning curves for conversion, operation time, and intraoperative blood loss are completed earlier, extensive experience may be needed to master the learning curve of MIDP.

A PRRX1 Signature Identifies TIM-3 and VISTA as Potential Immune Checkpoint Targets in a Subgroup of Microsatellite Stable Colorectal Cancer Liver Metastases.

Disease recurrence and drug resistance are major challenges in the clinical management of patients with colorectal cancer liver metastases (CLM), and because tumors are generally microsatellite stable (MSS), responses to immune therapies are poor. The mesenchymal phenotype is overrepresented in treatment-resistant cancers and is associated with an immunosuppressed microenvironment. The aim of this work was to molecularly identify and characterize a mesenchymal subgroup of MSS CLM to identify novel therapeutic approaches. We here generated a mesenchymal gene expression signature by analysis of resection specimens from 38 patients with CLM using ranked expression level of the epithelial-to-mesenchymal transition-related transcription factor PRRX1. Downstream pathway analysis based on the resulting gene signature was performed and independent, publicly available datasets were used to validate the findings. A subgroup comprising 16% of the analyzed CLM samples were classified as mesenchymal, or belonging to the PRRX1 high group. Analysis of the PRRX1 signature genes revealed a distinct immunosuppressive phenotype with high expression of immune checkpoints HAVCR2/TIM-3 and VISTA, in addition to the M2 macrophage marker CD163. The findings were convincingly validated in datasets from three external CLM cohorts. Upregulation of immune checkpoints HAVCR2/TIM-3 and VISTA in the PRRX1 high subgroup is a novel finding, and suggests immune evasion beyond the PD-1/PD-L1 axis, which may contribute to poor response to PD-1/PD-L1-directed immune therapy in MSS colorectal cancer. Importantly, these checkpoints represent potential novel opportunities for immune-based therapy approaches in a subset of MSS CLM. Significance: CLM is an important cause of colorectal cancer mortality where the majority of patients have yet to benefit from immunotherapies. In this study of gene expression profiling analyses, we uncovered novel immune checkpoint targets in a subgroup of patients with MSS CLMs harboring a mesenchymal phenotype.

Impact of neoadjuvant chemotherapy on the difficulty and outcomes of laparoscopic and robotic major liver resections for colorectal liver metastases: A propensity-score and coarsened exact-matched controlled study.

BACKGROUND: Minimal invasive liver resections are a safe alternative to open surgery. Different scoring systems considering different risks factors have been developed to predict the risks associated with these procedures, especially challenging major liver resections (MLR). However, the impact of neoadjuvant chemotherapy (NAT) on the difficulty of minimally invasive MLRs remains poorly investigated. METHODS: Patients who underwent laparoscopic and robotic MLRs for colorectal liver metastases (CRLM) performed across 57 centers between January 2005 to December 2021 were included in this analysis. Patients who did or did not receive NAT were matched based on 1:1 coarsened exact and 1:2 propensity-score matching. Pre- and post-matching comparisons were performed. RESULTS: In total, the data of 5189 patients were reviewed. Of these, 1411 procedures were performed for CRLM, and 1061 cases met the inclusion criteria. After excluding 27 cases with missing data on NAT, 1034 patients (NAT: n = 641; non-NAT: n = 393) were included. Before matching, baseline characteristics were vastly different. Before matching, the morbidity rate was significantly higher in the NAT-group (33.2% vs. 27.2%, p-value = 0.043). No significant differences were seen in perioperative outcomes after the coarsened exact matching. After the propensity-score matching, statistically significant higher blood loss (mean, 300 (SD 128-596) vs. 250 (SD 100-400) ml, p-value = 0.047) but shorter hospital stay (mean, 6 [4-8] vs. 6 [5-9] days, p-value = 0.043) were found in the NAT-group. CONCLUSION: The current study demonstrated that NAT had minimal impact on the difficulty and outcomes of minimally-invasive MLR for CRLM.

Transatlantic registries for minimally invasive liver surgery: towards harmonization.

BACKGROUND: Several registries focus on patients undergoing minimally invasive liver surgery (MILS). This study compared transatlantic registries focusing on the variables collected and differences in baseline characteristics, indications, and treatment in patients undergoing MILS. Furthermore, key variables were identified. METHODS: The five registries for liver surgery from North America (ACS-NSQIP), Italy, Norway, the Netherlands, and Europe were compared. A set of key variables were established by consensus expert opinion and compared between the registries. Anonymized data of all MILS procedures were collected (January 2014-December 2019). To summarize differences for all patient characteristics, treatment, and outcome, the relative and absolute largest differences (RLD, ALD) between the smallest and largest outcome per variable among the registries are presented. RESULTS: In total, 13,571 patients after MILS were included. Both 30- and 90-day mortality after MILS were below 1.1% in all registries. The largest differences in baseline characteristics were seen in ASA grade 3-4 (RLD 3.0, ALD 46.1%) and the presence of liver cirrhosis (RLD 6.4, ALD 21.2%). The largest difference in treatment was the use of neoadjuvant chemotherapy (RLD 4.3, ALD 20.6%). The number of variables collected per registry varied from 28 to 303. From the 46 key variables, 34 were missing in at least one of the registries. CONCLUSION: Despite considerable variation in baseline characteristics, indications, and treatment of patients undergoing MILS in the five transatlantic registries, overall mortality after MILS was consistently below 1.1%. The registries should be harmonized to facilitate future collaborative research on MILS for which the identified 46 key variables will be instrumental.

Comparison between the difficulty of laparoscopic limited liver resections of tumors located in segment 7 versus segment 8: An international multicenter propensity-score matched study.

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.