Surgical outcomes of laparoscopic and open resection of benign liver tumours in the Netherlands: a nationwide analysis

Background: Data on surgical outcomes of laparoscopic liver resection (LLR) versus open liver resection (OLR) of benign liver tumour (BLT) are scarce. This study aimed to provide a nationwide overview of postoperative outcomes after LLR and OLR of BLT. Methods: This was a nationwide retrospective study including all patients who underwent liver resection for hepatocellular adenoma, haemangioma and focal nodular hyperplasia in the Netherlands from 2014 to 2019. Propensity score matching (PSM) was applied to compare 30-day overall and major morbidity and 30-day mortality after OLR and LLR. Results: In total, 415 patients underwent BLT resection of whom 230 (55.4%) underwent LLR. PSM for OLR and LLR resulted in 250 matched patients. Median (IQR) length of stay was shorter after LLR than OLR (4 versus 6 days, 5.0-8.0, p < 0.001). Postoperative 30-day overall morbidity was lower after LLR than OLR (12.0% vs. 22.4%, p = 0.043). LLR was associated with reduced 30-day overall morbidity in multivariable analysis (aOR:0.46, CI:0.22-0.95, p = 0.043). Both 30-day major morbidity and 30-day mortality were not different. Conclusions: LLR for BLT is associated with shorter hospital stay and reduced overall morbidity and is preferred if technically feasible.Transplant surger

Implementation and outcome of robotic liver surgery in the Netherlands: a nationwide analysis

Objective:To determine the nationwide implementation and surgical outcome of minor and major robotic liver surgery (RLS) and assess the first phase of implementation of RLS during the learning curve. Background:RLS may be a valuable alternative to laparoscopic liver surgery. Nationwide population-based studies with data on implementation and outcome of RLS are lacking. Methods:Multicenter retrospective cohort study including consecutive patients who underwent RLS for all indications in 9 Dutch centers (August 2014-March 2021). Data on all liver resections were obtained from the mandatory nationwide Dutch Hepato Biliary Audit (DHBA) including data from all 27 centers for liver surgery in the Netherlands. Outcomes were stratified for minor, technically major, and anatomically major RLS. Learning curve effect was assessed using cumulative sum analysis for blood loss. Results:Of 9437 liver resections, 400 were RLS (4.2%) procedures including 207 minor (52.2%), 141 technically major (35.3%), and 52 anatomically major (13%). The nationwide use of RLS increased from 0.2% in 2014 to 11.9% in 2020. The proportion of RLS among all minimally invasive liver resections increased from 2% to 28%. Median blood loss was 150 mL (interquartile range 50-350 mL] and the conversion rate 6.3% (n=25). The rate of Clavien-Dindo grade >= III complications was 7.0% (n=27), median length of hospital stay 4 days (interquartile range 2-5) and 30-day/in-hospital mortality 0.8% (n=3). The R0 resection rate was 83.2% (n=263). Cumulative sum analysis for blood loss found a learning curve of at least 33 major RLS procedures. Conclusions:The nationwide use of RLS in the Netherlands has increased rapidly with currently one-tenth of all liver resections and one-fourth of all minimally invasive liver resections being performed robotically. Although surgical outcomes of RLS in selected patient seem favorable, future prospective studies should determine its added value.Surgical oncolog

The feasibility, proficiency, and mastery learning curves in 635 robotic pancreatoduodenectomies following a multicenter training program: "Standing on the Shoulders of Giants"

Objective: To assess the feasibility, proficiency, and mastery learning curves for robotic pancreatoduodenectomy (RPD) in "second-generation" RPD centers following a multicenter training program adhering to the IDEAL framework.Background: The long learning curves for RPD reported from "pioneering" expert centers may discourage centers interested in starting an RPD program. However, the feasibility, proficiency, and mastery learning curves may be shorter in "second-generation" centers that participated in dedicated RPD training programs, although data are lacking. We report on the learning curves for RPD in "second-generation" centers trained in a dedicated nationwide program.Methods: Post hoc analysis of all consecutive patients undergoing RPD in 7 centers that participated in the LAELAPS-3 training program, each with a minimum annual volume of 50 pancreatoduodenectomies, using the mandatory Dutch Pancreatic Cancer Audit (March 2016-December 2021). Cumulative sum analysis determined cutoffs for the 3 learning curves: operative time for the feasibility (1) risk-adjusted major complication (Clavien-Dindo grade >= III) for the proficiency, (2) and textbook outcome for the mastery, (3) learning curve. Outcomes before and after the cutoffs were compared for the proficiency and mastery learning curves. A survey was used to assess changes in practice and the most valued "lessons learned."Results: Overall, 635 RPD were performed by 17 trained surgeons, with a conversion rate of 6.6% (n=42). The median annual volume of RPD per center was 22.56.8. From 2016 to 2021, the nationwide annual use of RPD increased from 0% to 23% whereas the use of laparoscopic pancreatoduodenectomy decreased from 15% to 0%. The rate of major complications was 36.9% (n=234), surgical site infection 6.3% (n=40), postoperative pancreatic fistula (grade B/C) 26.9% (n=171), and 30-day/in-hospital mortality 3.5% (n=22). Cutoffs for the feasibility, proficiency, and mastery learning curves were reached at 15, 62, and 84 RPD. Major morbidity and 30-day/in-hospital mortality did not differ significantly before and after the cutoffs for the proficiency and mastery learning curves. Previous experience in laparoscopic pancreatoduodenectomy shortened the feasibility (-12 RPDs, -44%), proficiency (-32 RPDs, -34%), and mastery phase learning curve (-34 RPDs, -23%), but did not improve clinical outcome.Conclusions: The feasibility, proficiency, and mastery learning curves for RPD at 15, 62, and 84 procedures in "second-generation" centers after a multicenter training program were considerably shorter than previously reported from "pioneering" expert centers. The learning curve cutoffs and prior laparoscopic experience did not impact major morbidity and mortality. These findings demonstrate the safety and value of a nationwide training program for RPD in centers with sufficient volume.Surgical oncolog

Clinical added value of MRI to CT in patients scheduled for local therapy of colorectal liver metastases (CAMINO): study protocol for an international multicentre prospective diagnostic accuracy study

Background: Abdominal computed tomography (CT) is the standard imaging method for patients with suspected colorectal liver metastases (CRLM) in the diagnostic workup for surgery or thermal ablation. Diffusion-weighted and gadoxetic-acid-enhanced magnetic resonance imaging (MRI) of the liver is increasingly used to improve the detection rate and characterization of liver lesions. MRI is superior in detection and characterization of CRLM as compared to CT. However, it is unknown how MRI actually impacts patient management. The primary aim of the CAMINO study is to evaluate whether MRI has sufficient clinical added value to be routinely added to CT in the staging of CRLM. The secondary objective is to identify subgroups who benefit the most from additional MRI.Methods: In this international multicentre prospective incremental diagnostic accuracy study, 298 patients with primary or recurrent CRLM scheduled for curative liver resection or thermal ablation based on CT staging will be enrolled from 17 centres across the Netherlands, Belgium, Norway, and Italy. All study participants will undergo CT and diffusion-weighted and gadoxetic-acid enhanced MRI prior to local therapy. The local multidisciplinary team will provide two local therapy plans: first, based on CT-staging and second, based on both CT and MRI. The primary outcome measure is the proportion of clinically significant CRLM (CS-CRLM) detected by MRI not visible on CT. CS-CRLM are defined as liver lesions leading to a change in local therapeutical management. If MRI detects new CRLM in segments which would have been resected in the original operative plan, these are not considered CS-CRLM. It is hypothesized that MRI will lead to the detection of CS-CRLM in >= 10% of patients which is considered the minimal clinically important difference. Furthermore, a prediction model will be developed using multivariable logistic regression modelling to evaluate the predictive value of patient, tumor and procedural variables on finding CS-CRLM on MRI.Discussion: The CAMINO study will clarify the clinical added value of MRI to CT in patients with CRLM scheduled for local therapy. This study will provide the evidence required for the implementation of additional MRI in the routine work-up of patients with primary and recurrent CRLM for local therapy.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas

Clinical outcome of gastric banding and gastric bypass in morbidly obese patients

Obesity has become a global problem and an obesity epidemic has risen. Bariatric surgery has become the first treatment of choice in patients who have a BMI greater than 35 kg/m2 with significant comorbid conditions and patients who have a BMI greater than 40 kg/m2 with or without any significant comorbid conditions. Laparoscopic adjustable gastric banding (LAGB) and (laparoscopic) gastric bypass (GB) are the two procedures mostly performed worldwide. In Chapter 2 LAGB has shown to be a safe procedure, with good mid term weight loss results in the majority (77%) of the patients, but with a high reoperation rate. In Chapter 3 it is shown that after 8 years of follow-up, 39% of the patients were lost to follow-up after LAGB and the majority of these patients (60%) were therapy failures. Long term follow-up of the total LAGB group resulted in a fair outcome in 32% of patients. The most frequent complication and reason for reoperation after LAGB is slippage of the gastric band. Uncertainty exists of the best treatment of a slipped band. In Chapter 4 it is shown that rebanding for slippage is not a prognostic factor for inadequate weight loss. In patients successfully treated by LAGB, rebanding for band slippage should be considered, as good long term success was found in 62% of these patients. The main benefits of the GB are the high percentage (71%) of successfully treated patients, and the higher percentage of weight loss in the short term (Chapter 5). However, the GB is associated with surgery related mortality and morbidity. Comparing the two most performed procedures shows that significantly more patients had good treatment results (excess weight loss > 50 %) after a GB than after LAGB (76% versus 40% after 2 years of follow-up, P = 0,03) (Chapter 6). In terms of complications, the most obvious difference existed in severe early complications after GB compared to LAGB (11% vs 0%). In conclusion, the GB compared to LAGB results in increased weight loss, in a higher number of patients, but is associated with a higher incidence of severe early complications. A secondary GB procedure after failed LAGB (40-50%) is a technically more demanding procedure than primary GB. Our study presented in Chapter 7 shows that it can be performed equally safe and effective as a primary GB. In Chapter 8 we show that reconstructive surgery after successful bariatric surgery improves significantly patients’ physical functioning, mental well being, physical appearance, social acceptance, self-efficacy towards eating and intimacy. The contribution of reconstructive surgery plays a substantial role in the multidisciplinary treatment of the morbidly obese patient. Bariatric surgery has proven to be safe and the most effective answer to the obesity epidemic. In the near future a new definition of successful bariatric treatment should be formulated including weight loss, comorbidities and quality of life. This new consensus should be the purpose of future studies and lead to the selection of the appropriate bariatric procedure for the individual obese patient

Numerical and experimental investigation of a counter-current two-phase thermosyphon with cascading pools

An innovative design of a counter-current two-phase thermosyphon is investigated for the in-plane cooling of flat product structures. The thermosyphon features multiple pools staggered along the entire evaporator section, in which liquid flowing toward the bottom of the thermosyphon can be stored. The pools are used to cascade the working fluid to the evaporator end cap. Liquid accumulates in the pools until they overflow, thereby spreading the working fluid across the entire evaporator length rather than creating one liquid pool at the bottom end cap. Multiple of such thermosyphons operating in parallel can be used for low-gradient planar cooling of vertically oriented surfaces. A numerical model using a control volume approach is developed to predict and to validate the experimental results of this innovative design. The main advantages of the control volume approach are the adaptability of the entire model and the fast computational speed in comparison to elaborate fluid dynamics models. Empirical correlations are used for the modeling of the heat transfer coefficients and friction factors of the counter-current flow. A proof of principle is given by observing a prototype that was milled into a copper bar. Next to logging temperature measurements, the prototype had a glass top plate to visually record the working fluid behavior. The model presented is well suitable for the early stages of thermosyphon design studies and for the impact evaluation of design changes

Population-based study on practice variation regarding preoperative systemic chemotherapy in patients with colorectal liver metastases and impact on short-term outcomes

Introduction: Definitions regarding resectability and hence indications for preoperative chemotherapy vary. Use of preoperative chemotherapy may influence postoperative outcomes. This study aimed to assess the variation in use of preoperative chemotherapy for CRLM and related postoperative outcomes in the Netherlands.Materials and methods: All patients who underwent liver resection for CRLM in the Netherlands between 2014 and 2018 were included from a national database. Case-mix factors contributing to the use of preoperative chemotherapy, hospital variation and postoperative outcomes were assessed using multivariable logistic regression. Postoperative outcomes were postoperative complicated course (PCC), 30day morbidity and 30-day mortality.Results: In total, 4469 patients were included of whom 1314 patients received preoperative chemotherapy and 3155 patients did not. Patients receiving chemotherapy were significantly younger (mean age (+SD) 66.3 (10.4) versus 63.2 (10.2) p < 0.001) and had less comorbidity (Charlson scores 2+ (24% versus 29%, p = 0.010). Unadjusted hospital variation concerning administration of preoperative chemotherapy ranged between 2% and 55%. After adjusting for case-mix factors, three hospitals administered significantly more preoperative chemotherapy than expected and six administered significantly less preoperative chemotherapy than expected. PCC was 12.1%, 30-day morbidity was 8.8% and 30-day mortality was 1.5%. No association between preoperative chemotherapy and PCC (OR 1.24, 0.98-1.55, p = 0.065), 30-day morbidity (OR 1.05, 0.81-1.39, p = 0.703) or with 30-day mortality (OR 1.22, 0.75-2.09, p = 0.467) was found.Conclusion: Significant hospital variation in the use of preoperative chemotherapy for CRLM was present in the Netherlands. No association between postoperative outcomes and use of preoperative chemotherapy was found. (C) 2020 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.Surgical oncolog

Case-mix adjustment to compare nationwide hospital performances after resection of colorectal liver metastases

Background: Differences in patient demographics and disease burden can influence comparison of hospital performances. This study aimed to provide a case-mix model to compare short-term postoperative outcomes for patients undergoing liver resection for colorectal liver metastases (CRLM).Methods: This retrospective, population-based study included all patients who underwent liver resection for CRLM between 2014 and 2018 in the Netherlands. Variation in case-mix variables between hospitals and influence on postoperative outcomes was assessed using multivariable logistic regression. Primary outcomes were 30-day major morbidity and 30-day mortality. Validation of results was performed on the data from 2019.Results: In total, 4639 patients were included in 28 hospitals. Major morbidity was 6.2% and mortality was 1.4%. Uncorrected major morbidity ranged from 3.3% to 13.7% and mortality ranged from 0.0% to 5.0%. between hospitals. Significant differences between hospitals were observed for age higher than 80 (0.0%-17.1%, p < 0.001), ASA 3 or higher (3.3%-36.3%, p < 0.001), histopathological parenchymal liver disease (0.0%-47.1%, p < 0.001), history of liver resection (8.1%-36.3%, p < 0.001), major liver resection (6.7%-38.0%, p < 0.001) and synchronous metastases (35.5%-62.1%, p < 0.001). Expected 30-day major morbidity between hospitals ranged from 6.4% to 11.9% and expected 30-day mortality ranged from 0.6% to 2.9%. After case-mix correction no significant outliers concerning major morbidity and mortality remained. Validation on patients who underwent liver resection for CRLM in 2019 affirmed these outcomes.Conclusion: Case-mix adjustment is a prerequisite to allow for institutional comparison of short-term postoperative outcomes after liver resection for CRLM. (C) 2020 University Medical Center Groningen. Published by Elsevier Ltd.Surgical oncolog

Nationwide oncological networks for resection of colorectal liver metastases in the Netherlands: differences and postoperative outcomes

Introduction: Widespread differences in patient demographics and disease burden between hospitals for resection of colorectal liver metastases (CRLM) have been described. In the Netherlands, networks consisting of at least one tertiary referral centre and several regional hospitals have been established to optimize treatment and outcomes. The aim of this study was to assess variation in case-mix, and outcomes between these networks.Methods: This was a population-based study including all patients who underwent CRLM resection in the Netherlands between 2014 and 2019. Variation in case-mix and outcomes between seven networks covering the whole country was evaluated. Differences in case-mix, expected 30-day major morbidity (Clavien-Dindo >= 3a) and 30-day mortality between networks were assessed.Results: In total 5383 patients were included. Thirty-day major morbidity was 5.7% and 30-day mortality was 1.5%. Significant differences between networks were observed for Charlson Comorbidity Index, ASA 3+, previous liver resection, liver disease, preoperative MRI, preoperative chemotherapy, >= 3 CRLM, diameter of largest CRLM >= 55 mm, major resection, combined resection and ablation, rectal primary tumour, bilobar and extrahepatic disease. Uncorrected 30-day major morbidity ranged between 3.3% and 13.1% for hospitals, 30-day mortality ranged between 0.0% and 4.5%. Uncorrected 30-day major morbidity ranged between 4.4% and 6.0% for networks, 30-day mortality ranged between 0.0% and 2.5%. No negative outliers were observed after case-mix correction.Conclusion: Variation in case-mix and outcomes are considerably smaller on a network level as compared to a hospital level. Therefore, auditing is more meaningful at a network level and collaboration of hospitals within networks should be pursued. (C) 2021 Published by Elsevier Ltd.Analysis and support of clinical decision makin

Outcomes of a Multicenter Training Program in Robotic Pancreatoduodenectomy (LAELAPS-3)

Objective:To assess feasibility and safety of a multicenter training program in robotic pancreatoduodenectomy (RPD) adhering to the IDEAL framework for implementation of surgical innovation. Background:Good results for RPD have been reported from single center studies. However, data on feasibility and safety of implementation through a multicenter training program in RPD are lacking. Methods:A multicenter training program in RPD was designed together with the University of Pittsburgh Medical Center, including an online video bank, robot simulation exercises, biotissue drills, and on-site proctoring. Benchmark patients were based on the criteria of Clavien. Outcomes were collected prospectively (March 2016-October 2019). Cumulative sum analysis of operative time was performed to distinguish the first and second phase of the learning curve. Outcomes were compared between both phases of the learning curve. Trends in nationwide use of robotic and laparoscopic PD were assessed in the Dutch Pancreatic Cancer Audit. Results:Overall, 275 RPD procedures were performed in seven centers by 15 trained surgeons. The recent benchmark criteria for low-risk PD were met by 125 (45.5%) patients. The conversion rate was 6.5% (n = 18) and median blood loss 250ml [interquartile range (IQR) 150-500]. The rate of Clavien-Dindo grade >= III complications was 44.4% (n = 122), postoperative pancreatic fistula (grade B/C) rate 23.6% (n = 65), 90-day complication-related mortality 2.5% (n = 7) and 90-day cancer-related mortality 2.2.% (n = 6). Median postoperative hospital stay was 12 days (IQR 8-20). In the subgroup of patients with pancreatic cancer (n = 80), the major complication rate was 31.3% and POPF rate was 10%. Cumulative sum analysis for operative time found a learning curve inflection point at 22 RPDs (IQR 10-35) with similar rates of Clavien-Dindo grade >= III complications in the first and second phase (43.4% vs 43.8%, P = 0.956, respectively). During the study period the nationwide use of laparoscopic PD reduced from 15% to 1%, whereas the use of RPD increased from 0% to 25%. Conclusions:This multicenter RPD training program in centers with sufficient surgical volume was found to be feasible without a negative impact of the learning curve on clinical outcomes