Artificial intelligence-aided ultrasound imaging in hepatopancreatobiliary surgery: where are we now?

BACKGROUND: Artificial intelligence (AI) models have been applied in various medical imaging modalities and surgical disciplines, however the current status and progress of ultrasound-based AI models within hepatopancreatobiliary surgery have not been evaluated in literature. Therefore, this review aimed to provide an overview of ultrasound-based AI models used for hepatopancreatobiliary surgery, evaluating current advancements, validation, and predictive accuracies. METHOD: Databases PubMed, EMBASE, Cochrane, and Web of Science were searched for studies using AI models on ultrasound for patients undergoing hepatopancreatobiliary surgery. To be eligible for inclusion, studies needed to apply AI methods on ultrasound imaging for patients undergoing hepatopancreatobiliary surgery. The Probast risk of bias tool was used to evaluate the methodological quality of AI methods. RESULTS: AI models have been primarily used within hepatopancreatobiliary surgery, to predict tumor recurrence, differentiate between tumoral tissues, and identify lesions during ultrasound imaging. Most studies have combined radiomics with convolutional neural networks, with AUCs up to 0.98. CONCLUSION: Ultrasound-based AI models have demonstrated promising accuracies in predicting early tumoral recurrence and even differentiating between tumoral tissue types during and after hepatopancreatobiliary surgery. However, prospective studies are required to evaluate if these results will remain consistent and externally valid.

Training in robotic-assisted surgery: a systematic review of training modalities and objective and subjective assessment methods.

INTRODUCTION: The variety of robotic surgery systems, training modalities, and assessment tools within robotic surgery training is extensive. This systematic review aimed to comprehensively overview different training modalities and assessment methods for teaching and assessing surgical skills in robotic surgery, with a specific focus on comparing objective and subjective assessment methods. METHODS: A systematic review was conducted following the PRISMA guidelines. The electronic databases Pubmed, EMBASE, and Cochrane were searched from inception until February 1, 2022. Included studies consisted of robotic-assisted surgery training (e.g., box training, virtual reality training, cadaver training and animal tissue training) with an assessment method (objective or subjective), such as assessment forms, virtual reality scores, peer-to-peer feedback or time recording. RESULTS: The search identified 1591 studies. After abstract screening and full-texts examination, 209 studies were identified that focused on robotic surgery training and included an assessment tool. The majority of the studies utilized the da Vinci Surgical System, with dry lab training being the most common approach, followed by the da Vinci Surgical Skills Simulator. The most frequently used assessment methods included simulator scoring system (e.g., dVSS score), and assessment forms (e.g., GEARS and OSATS). CONCLUSION: This systematic review provides an overview of training modalities and assessment methods in robotic-assisted surgery. Dry lab training on the da Vinci Surgical System and training on the da Vinci Skills Simulator are the predominant approaches. However, focused training on tissue handling, manipulation, and force interaction is lacking, despite the absence of haptic feedback. Future research should focus on developing universal objective assessment and feedback methods to address these limitations as the field continues to evolve.

Artificial intelligence-powered clinical decision making within gastrointestinal surgery: A systematic review.

BACKGROUND: Clinical decision-making in gastrointestinal surgery is complex due to the unpredictability of tumoral behavior and postoperative complications. Artificial intelligence (AI) could aid in clinical decision-making by predicting these surgical outcomes. The current status of AI-based clinical decision-making within gastrointestinal surgery is unknown in recent literature. This review aims to provide an overview of AI models used for clinical decision-making within gastrointestinal surgery. METHODS: A systematic literature search was performed in databases PubMed, EMBASE, Cochrane, and Web of Science. To be eligible for inclusion, studies needed to use AI models for clinical decision-making involving patients undergoing gastrointestinal surgery. Studies reporting on reviews, children, and study abstracts were excluded. The Probast risk of bias tool was used to evaluate the methodological quality of AI methods. RESULTS: Out of 1073 studies, 10 articles were eligible for inclusion. AI models have been used to make clinical decisions between surgical procedures, selection of chemotherapy, selection of postoperative follow up programs, and implementation of a temporary ileostomy. Most studies have used a Random Forest or Gradient Boosting model with AUCs up to 0.97. All studies involved a retrospective study design, in which external validation was performed in one study. CONCLUSIONS: This review shows that AI models have the potentiality to select the most optimal treatments for patients undergoing gastrointestinal surgery. Clinical benefits could be gained if AI models were used for clinical decision-making. However, prospective studies and randomized controlled trials will reveal the definitive role of AI models in clinical decision-making.

Impact of 18FFDG-PET/CT and Laparoscopy in Staging of Locally Advanced Gastric Cancer: A Cost Analysis in the Prospective Multicenter PLASTIC-Study.

BACKGROUND: Unnecessary D2-gastrectomy and associated costs can be prevented after detecting non-curable gastric cancer, but impact of staging on treatment costs is unclear. This study determined the cost impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FFDG-PET/CT) and staging laparoscopy (SL) in gastric cancer staging. MATERIALS AND METHODS: In this cost analysis, four staging strategies were modeled in a decision tree: (1) 18FFDG-PET/CT first, then SL, (2) SL only, (3) 18FFDG-PET/CT only, and (4) neither SL nor 18FFDG-PET/CT. Costs were assessed on the basis of the prospective PLASTIC-study, which evaluated adding 18FFDG-PET/CT and SL to staging advanced gastric cancer (cT3-4 and/or cN+) in 18 Dutch hospitals. The Dutch Healthcare Authority provided 18FFDG-PET/CT unit costs. SL unit costs were calculated bottom-up. Gastrectomy-associated costs were collected with hospital claim data until 30 days postoperatively. Uncertainty was assessed in a probabilistic sensitivity analysis (1000 iterations). RESULTS: 18FFDG-PET/CT costs were €1104 including biopsy/cytology. Bottom-up calculations totaled €1537 per SL. D2-gastrectomy costs were €19,308. Total costs per patient were €18,137 for strategy 1, €17,079 for strategy 2, and €19,805 for strategy 3. If all patients undergo gastrectomy, total costs were €18,959 per patient (strategy 4). Performing SL only reduced costs by €1880 per patient. Adding 18FFDG-PET/CT to SL increased costs by €1058 per patient; IQR €870-1253 in the sensitivity analysis. CONCLUSIONS: For advanced gastric cancer, performing SL resulted in substantial cost savings by reducing unnecessary gastrectomies. In contrast, routine 18FFDG-PET/CT increased costs without substantially reducing unnecessary gastrectomies, and is not recommended due to limited impact with major costs. TRIAL REGISTRATION: NCT03208621. This trial was registered prospectively on 30-06-2017.

ChatGPT in surgery: a revolutionary innovation?

ChatGPT has brought about a new era of digital health, as this model has become prominent and been rapidly developing since its release. ChatGPT may be able to facilitate improvements in surgery as well; however, the influence of ChatGPT on surgery is largely unknown at present. Therefore, the present study reports on the current applications of ChatGPT in the field of surgery, evaluating its workflow, practical implementations, limitations, and future perspectives. A literature search was performed using the PubMed and Embase databases. The initial search was performed from its inception until July 2023. This study revealed that ChatGPT has promising capabilities in areas of surgical research, education, training, and practice. In daily practice, surgeons and surgical residents can be aided in performing logistics and administrative tasks, and patients can be more efficiently informed about the details of their condition. However, priority should be given to establishing proper policies and protocols to ensure the safe and reliable use of this model.

Variation in HbA1c in Patients with Obesity and type 2 Diabetes Mellitus 12 months after Laparoscopic One-Anastomosis Gastric Bypass and Laparoscopic Roux-en-Y Gastric Bypass: a Retrospective Matched Cohort Study.

BACKGROUND: Glycemic control is an important goal of bariatric surgery in patients with type 2 diabetes mellitus (T2DM) and obesity. The laparoscopic one-anastomosis gastric bypass (OAGB) has potential metabolic benefits over the laparoscopic Roux-en-Y gastric bypass (RYGB). Aim of this study is to examine whether RYGB or OAGB grants better glycemic control 12 months post-surgery. METHODS: For this retrospective cohort study, patients with T2DM and obesity, who underwent primary OAGB between 2008 and 2017 were reviewed. For each OAGB patient, three primary RYGB patients were matched for age, gender and body mass index (BMI). Glycemic control was expressed by the glycated hemoglobin (HbA1c), which was measured pre- and 12 months post-operatively. Weight loss was reported in percentage total weight loss (%TWL). RESULTS: A total of 152 patients, of whom 38 had OAGB and 114 RYGB, were included. Mean (standard deviation (SD)) HbA1c was 7.49 (1.51)% in the OAGB group and 7.56(1.23)% in the RYGB group at baseline. Twelve months after surgery the mean (SD) HbA1c dropped to 5.73 (0.71)% after OAGB and 6.09 (0.76)% after RYGB (adjusted p = 0.011). The mean (SD) BMI was reduced from 42.5(6.3) kg/m2 to 29.6(4.7) kg/m2 after OAGB and 42.3(5.8) kg/m2 to 29.9 (4.5) kg/m2 after RYGB; reflecting 30.3 (6.8) %TWL post-OAGB and 29.0 (7.3) %TWL post-RYGB (p = 0.34). CONCLUSION: This study indicates that OAGB leads to lower HbA1c one year after surgery compared to RYGB, without a difference in weight loss. Prospective (randomized) studies are needed to ascertain the most optimal metabolic treatment for patients with obesity and T2DM.

Minimally invasive versus open gastrectomy for gastric cancer. A pooled analysis of two European randomized controlled trials.

INTRODUCTION: Minimally invasive techniques have shown better short term and similar oncological outcomes compared to open techniques in the treatment of gastric cancer in Asian countries. It remains unknown whether these outcomes can be extrapolated to Western countries, where patients often present with advanced gastric cancer. MATERIALS AND METHODS: A pooled analysis of two Western randomized controlled trials (STOMACH and LOGICA trial) comparing minimally invasive gastrectomy (MIG) and open gastrectomy (OG) in advanced gastric cancer was performed. Postoperative recovery (complications, mortality, hospital stay), oncological outcomes (lymph node yield, radical resection rate, 1-year survival), and quality of life was assessed. RESULTS: Three hundred and twenty-one patients were included from both trials. Of these, 162 patients (50.5%) were allocated to MIG and 159 patients (49.5%) to OG. A significant difference was seen in blood loss in favor of MIG (150 vs. 260 mL, p < 0.001), whereas duration of surgery was in favor of OG (180 vs. 228.5 min, p = 0.005). Postoperative recovery, oncological outcomes and quality of life were similar between both groups. CONCLUSION: MIG showed no difference to OG regarding postoperative recovery, oncological outcomes or quality of life, and is therefore a safe alternative to OG in patients with advanced gastric cancer.

The burden of abdominal pain after bariatric surgery in terms of diagnostic testing: the OPERATE study.

BACKGROUND: Abdominal pain after bariatric surgery (BS) is frequently observed. Despite numerous diagnostic tests, the cause of abdominal pain is not always found. OBJECTIVES: To quantify type and number of diagnostic tests performed in patients with abdominal pain after BS and evaluate the burden and their yield in the diagnostic process. SETTING: A bariatric center in the Netherlands. METHODS: In this prospective study, we included patients who presented with abdominal pain after BS between December 1, 2020, and December 1, 2021. All diagnostic tests and reoperations performed during one episode of abdominal pain were scored using a standardized protocol. RESULTS: A total of 441 patients were included; 401 (90.9%) were female, median time after BS was 37.0 months (IQR, 11.0-66.0) and mean percentage total weight loss was 31.41 (SD, 10.53). In total, 715 diagnostic tests were performed, of which 355 were abdominal CT scans, 155 were ultrasounds, and 106 were gastroscopies. These tests yielded a possible explanation for the pain in 40.2% of CT scans, 45.3% of ultrasounds, and 34.7% of gastroscopies. The diagnoses of internal herniation, ileus, and nephrolithiasis generally required only 1 diagnostic test, whereas patients with anterior cutaneous nerve entrapment syndrome, irritable bowel syndrome, and constipation required several tests before diagnosis. Even after several negative tests, a diagnosis was still found in the subsequent test: 86.7% of patients with 5 or more tests had a definitive diagnoses. Reoperations were performed in 37.2% of patients. CONCLUSION: The diagnostic burden in patients with abdominal pain following BS is high. The most frequently performed diagnostic test is an abdominal CT scan, yielding the highest number of diagnoses in these patients.

Evolution in Laparoscopic Gastrectomy From a Randomized Controlled Trial Through National Clinical Practice.

OBJECTIVE: To examine the influence of the LOGICA RCT (randomized controlled trial) upon the practice and outcomes of laparoscopic gastrectomy within the Netherlands. BACKGROUND: Following RCTs the dissemination of complex interventions has been poorly studied. The LOGICA RCT included 10 Dutch centers and compared laparoscopic to open gastrectomy. METHODS: Data were obtained from the Dutch Upper Gastrointestinal Cancer Audit (DUCA) on all gastrectomies performed in the Netherlands (2012-2021), and the LOGICA RCT from 2015 to 2018. Multilevel multivariable logistic regression analyses were performed to assess the effect of laparoscopic versus open gastrectomy upon clinical outcomes before, during, and after the LOGICA RCT. RESULTS: Two hundred eleven patients from the LOGICA RCT (105 open vs 106 laparoscopic) and 4131 patients from the DUCA data set (1884 open vs 2247 laparoscopic) were included. In 2012, laparoscopic gastrectomy was performed in 6% of patients, increasing to 82% in 2021. No significant effect of laparoscopic gastrectomy on postoperative clinical outcomes was observed within the LOGICA RCT. Nationally within DUCA, a shift toward a beneficial effect of laparoscopic gastrectomy upon complications was observed, reaching a significant reduction in overall [adjusted odds ratio (aOR):0.62; 95% CI: 0.46-0.82], severe (aOR: 0.64; 95% CI: 0.46-0.90) and cardiac complications (aOR: 0.51; 95% CI: 0.30-0.89) after the LOGICA trial. CONCLUSIONS: The wider benefits of the LOGICA trial included the safe dissemination of laparoscopic gastrectomy across the Netherlands. The robust surgical quality assurance program in the design of the LOGICA RCT was crucial to facilitate the national dissemination of the technique following the trial and reducing potential patient harm during surgeons learning curve.

A Prospective Study on the Diagnoses for Abdominal Pain After Bariatric Surgery: The OPERATE Study.

PURPOSE: Long-term follow-up after bariatric surgery (BS) reveals high numbers of patients with abdominal pain that often remains unexplained. The aim of this prospective study was to give an overview of diagnoses for abdominal pain, percentage of unexplained complaints, number and yield of follow-up visits, and time to establish a diagnosis. MATERIALS AND METHODS: Patients who visited the Spaarne Gasthuis Hospital, The Netherlands, between December 2020 and December 2021 for abdominal pain after BS, were eligible and followed throughout the entire episode of abdominal pain. Distinction was made between presumed and definitive diagnoses. RESULTS: The study comprised 441 patients with abdominal pain; 401 (90.9%) females, 380 (87.7%) had Roux-en-Y gastric bypass, mean (SD) % total weight loss was 31.4 (10.5), and median (IQR) time after BS was 37.0 (11.0-66.0) months. Most patients had 1-5 follow-up visits. Readmissions and reoperations were present in 212 (48.1%) and 164 (37.2%) patients. At the end of the episode, 88 (20.0%) patients had a presumed diagnosis, 183 (41.5%) a definitive diagnosis, and 170 (38.5%) unexplained complaints. Most common definitive diagnoses were cholelithiasis, ulcers, internal herniations, and presumed diagnoses irritable bowel syndrome (IBS), anterior cutaneous nerve entrapment syndrome, and constipation. Median (IQR) time to presumed diagnoses, definitive diagnoses, or unexplained complaints was 16.0 (3.8-44.5), 2.0 (0.0-31.5), and 13.5 (1.0-53.8) days (p < 0.001). Patients with IBS more often had unexplained complaints (OR 95%CI: 4.457 [1.455-13.654], p = 0.009). At the end, 71 patients (16.1%) still experienced abdominal pain. CONCLUSION: Over a third of abdominal complaints after BS remains unexplained. Most common diagnoses were cholelithiasis, ulcers, and internal herniations.

Three-year survival and distribution of lymph node metastases in gastric cancer following neoadjuvant chemotherapy: results from a European randomized clinical trial.

BACKGROUND: Adequate lymphadenectomy is an important step in gastrectomy for cancer, with a modified D2 lymphadenectomy being recommended for advanced gastric cancers. When assessing a novel technique for the treatment of gastric cancer, lymphadenectomy should be non-inferior. The aim of this study was to assess completeness of lymphadenectomy and distribution patterns between open total gastrectomy (OTG) and minimally invasive total gastrectomy (MITG) in the era of peri-operative chemotherapy. METHODS: This is a retrospective analysis of the STOMACH trial, a randomized clinical trial in thirteen hospitals in Europe. Patients were randomized between OTG and MITG for advanced gastric cancer after neoadjuvant chemotherapy. Three-year survival, number of resected lymph nodes, completeness of lymphadenectomy, and distribution patterns were examined. RESULTS: A total of 96 patients were included in this trial and randomized between OTG (49 patients) and MITG (47 patients). No difference in 3-year survival was observed, this was 57.1% in OTG group versus 46.8% in MITG group (P = 0.186). The mean number of examined lymph nodes per patient was 44.3 ± 16.7 in the OTG group and 40.7 ± 16.3 in the MITG group (P = 0.209). D2 lymphadenectomy of 71.4% in the OTG group and 74.5% in the MITG group was performed according to the surgeons; according to the pathologist compliance to D2 lymphadenectomy was 30% in the OTG group and 36% in the MITG group. Tier 2 lymph node metastases (stations 7-12) were observed in 19.6% in the OTG group versus 43.5% in the MITG group (P = 0.024). CONCLUSION: No difference in 3-year survival was observed between open and minimally invasive gastrectomy. No differences were observed for lymph node yield and type of lymphadenectomy. Adherence to D2 lymphadenectomy reported by the pathologist was markedly low.

Pain and Opioid Consumption After Laparoscopic Versus Open Gastrectomy for Gastric Cancer: A Secondary Analysis of a Multicenter Randomized Clinical Trial (LOGICA-Trial).

BACKGROUND: Laparoscopic gastrectomy could reduce pain and opioid consumption, compared to open gastrectomy. However, it is difficult to judge the clinical relevance of this reduction, since these outcomes are reported in few randomized trials and in limited detail. METHODS: This secondary analysis of a multicenter randomized trial compared laparoscopic versus open gastrectomy for resectable gastric adenocarcinoma (cT1-4aN0-3bM0). Postoperative pain was analyzed by opioid consumption in oral morphine equivalents (OME, mg/day) at postoperative day (POD) 1-5, WHO analgesic steps, and Numeric Rating Scales (NRS, 0-10) at POD 1-10 and discharge. Regression and mixed model analyses were performed, with and without correction for epidural analgesia. RESULTS: Between 2015 and 2018, 115 patients in the laparoscopic group and 110 in the open group underwent surgery. Some 16 patients (14%) in the laparoscopic group and 73 patients (66%) in the open group received epidural analgesia. At POD 1-3, mean opioid consumption was 131, 118, and 53 mg OME lower in the laparoscopic group, compared to the open group, respectively (all p < 0.001). After correcting for epidural analgesia, these differences remained significant at POD 1-2 (47 mg OME, p = 0.002 and 69 mg OME, p < 0.001, respectively). At discharge, 27% of patients in the laparoscopic group and 43% patients in the open group used oral opioids (p = 0.006). Mean highest daily pain scores were between 2 and 4 at all PODs, < 2 at discharge, and did not relevantly differ between treatment arms. CONCLUSION: In this multicenter randomized trial, postoperative pain was comparable between laparoscopic and open gastrectomy. After laparoscopic gastrectomy, this was generally achieved without epidural analgesia and with fewer opioids. TRIAL REGISTRATION: NCT02248519.

The effect of anastomotic leakage on the incidence of recurrence after tri-modality therapy for esophageal adenocarcinomas.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRTx) reduces the incidence of recurrence, while anastomotic leakage has shown increase the risk of recurrence. The primary objective of this retrospective study was to investigate the incidence and pattern of recurrence and secondary median recurrence-free interval and post-recurrence survival in patients with and without anastomotic leakage after multimodal therapy for esophageal adenocarcinoma. METHODS: Patients with recurrence after multimodal therapy between 2010 and 2018 were included. RESULTS: Six hundred and eighteen patients were included, 91 (14.7%) had leakage and 278 (45.0%) recurrence. Patients with leakage did not develop recurrence more often (48.4%) than those without (44.4%, [p = 0.484]). Recurrence-free interval for patients with (n = 44) and without leakage (n = 234) was 39 and 52 weeks, respectively (p = 0.049). Post-recurrence survival was 11 and 16 weeks, respectively (p = 0.702). Specified by recurrence site, post-recurrence survival for loco-regional recurrences was 27 versus 33 weeks (p = 0.387) for patients with and without leakage, for distant 9 versus 13 (p = 0.999), and for combined 11 versus 18 weeks (p = 0.492). CONCLUSION AND DISCUSSION: No higher incidence of recurrent disease was observed in patients with anastomotic leakage, however it is associated with a shorter recurrence-free interval. This could have implications for surveillance, as early detection of recurrent disease could influence therapeutic options.

Crossover-effects in technical skills between laparoscopy and robot-assisted surgery.

INTRODUCTION: Robot-assisted surgery is often performed by experienced laparoscopic surgeons. However, this technique requires a different set of technical skills and surgeons are expected to alternate between these approaches. The aim of this study is to investigate the crossover effects when switching between laparoscopic and robot-assisted surgery. METHODS: An international multicentre crossover study was conducted. Trainees with distinctly different levels of experience were divided into three groups (novice, intermediate, expert). Each trainee performed six trials of a standardized suturing task using a laparoscopic box trainer and six trials using the da Vinci surgical robot. Both systems were equipped with the ForceSense system, measuring five force-based parameters for objective assessment of tissue handling skills. Statistical comparison was done between the sixth and seventh trial to identify transition effects. Unexpected changes in parameter outcomes after the seventh trial were further investigated. RESULTS: A total of 720 trials, performed by 60 participants, were analysed. The expert group increased their tissue handling forces with 46% (maximum impulse 11.5 N/s to 16.8 N/s, p = 0.05), when switching from robot-assisted surgery to laparoscopy. When switching from laparoscopy to robot-assisted surgery, intermediates and experts significantly decreased in motion efficiency (time (sec), resp. 68 vs. 100, p = 0.05, and 44 vs. 84, p = 0.05). Further investigation between the seventh and ninth trial showed that the intermediate group increased their force exertion with 78% (5.1 N vs. 9.1 N, p = 0.04), when switching to robot-assisted surgery. CONCLUSION: The crossover effects in technical skills between laparoscopic and robot-assisted surgery are highly depended on the prior experience with laparoscopic surgery. Where experts can alternate between approaches without impairment of technical skills, novices and intermediates should be aware of decay in efficiency of movement and tissue handling skills that could impact patient safety. Therefore, additional simulation training is advised to prevent from undesired events.

Are male patients undergoing bariatric surgery less healthy than female patients?

BACKGROUND: Male patients are underrepresented in bariatric surgery (BS) despite a relatively equal proportion of men and women experiencing obesity. OBJECTIVES: Differences in frequency and severity of obesity-associated medical problems (OAMPs) between men and women undergoing BS or in a control group (HELIUS [HEalthy Life In an Urban Setting]) were evaluated. The hypothesis was that men undergoing BS are less healthy than women. SETTING: A cross-sectional study of 2 cohorts undergoing BS in 2013 (BS2013) and 2019 (BS2019) and a control group of patients with severe obesity from a general population (HELIUS). METHODS: Characteristics concerning weight and OAMPs, medication usage, intoxications, postoperative complications (for BS2019) were compared between men and women. Members of the HELIUS cohort were tested for eligibility for BS. RESULTS: Of 3244 patients included, the majority were female (>78.4%). Median (interquartile range) age and body mass index (kg/m2) in male versus female patients were 47.0 (41.0-53.8) versus 43.0 (36.0-51.0) years and 41.5 (38.4-45.2) versus 42.3 (40.2-45.9), respectively, in BS2013, and 52.0 (39.8-57.0) versus 45.0 (35.0-53.0) years and 40.4 (37.4-43.8) versus 41.3 (39.0-44.1) in BS2019 (P < .05). The rates of men with OAMPs were 71.4% and 82.0% compared with 50.2% and 56.9% of women in BS2013 and BS2019, respectively. Overall medication usage was higher in male patients (P = .014). In BS2019, male patients exhibited a higher median HbA1C (P < .001) and blood pressure (P = .003) and used more antihypertensives and antidiabetics (P = .004). Postoperative complications did not differ between men and women. In the control cohort, 66.5% of men and 66.6% of women were eligible for BS. CONCLUSION: Men undergoing BS more often experience OAMPs than women, and OAMPs are more advanced in men.

Cost-effectiveness of Laparoscopic vs Open Gastrectomy for Gastric Cancer: An Economic Evaluation Alongside a Randomized Clinical Trial.

Importance: Laparoscopic gastrectomy is rapidly being adopted worldwide as an alternative to open gastrectomy to treat gastric cancer. However, laparoscopic gastrectomy might be more expensive as a result of longer operating times and more expensive surgical materials. To date, the cost-effectiveness of both procedures has not been prospectively evaluated in a randomized clinical trial. Objective: To evaluate the cost-effectiveness of laparoscopic compared with open gastrectomy. Design, Setting, and Participants: In this multicenter randomized clinical trial of patients undergoing total or distal gastrectomy in 10 Dutch tertiary referral centers, cost-effectiveness data were collected alongside a multicenter randomized clinical trial on laparoscopic vs open gastrectomy for resectable gastric adenocarcinoma (cT1-4aN0-3bM0). A modified societal perspective and 1-year time horizon were used. Costs were calculated on the individual patient level by using hospital registry data and medical consumption and productivity loss questionnaires. The unit costs of laparoscopic and open gastrectomy were calculated bottom-up. Quality-adjusted life-years (QALYs) were calculated with the EuroQol 5-dimension questionnaire, in which a value of 0 indicates death and 1 indicates perfect health. Missing questionnaire data were imputed with multiple imputation. Bootstrapping was performed to estimate the uncertainty surrounding the cost-effectiveness. The study was conducted from March 17, 2015, to August 20, 2018. Data analyses were performed between September 1, 2020, and November 17, 2021. Interventions: Laparoscopic vs open gastrectomy. Main Outcomes and Measures: Evaluations in this cost-effectiveness analysis included total costs and QALYs. Results: Between 2015 and 2018, 227 patients were included. Mean (SD) age was 67.5 (11.7) years, and 140 were male (61.7%). Unit costs for initial surgery were calculated to be €8124 (US $8087) for laparoscopic total gastrectomy, €7353 (US $7320) for laparoscopic distal gastrectomy, €6584 (US $6554) for open total gastrectomy, and €5893 (US $5866) for open distal gastrectomy. Mean total costs after 1-year follow-up were €26 084 (US $25 965) in the laparoscopic group and €25 332 (US $25 216) in the open group (difference, €752 [US $749; 3.0%]). Mean (SD) QALY contributions during 1 year were 0.665 (0.298) in the laparoscopic group and 0.686 (0.288) in the open group (difference, -0.021). Bootstrapping showed that these differences between treatment groups were relatively small compared with the uncertainty of the analysis. Conclusions and Relevance: Although the laparoscopic gastrectomy itself was more expensive, after 1-year follow-up, results suggest that differences in both total costs and effectiveness were limited between laparoscopic and open gastrectomy. These results support centers' choosing, based on their own preference, whether to (de)implement laparoscopic gastrectomy as an alternative to open gastrectomy.

Machine learning applications in upper gastrointestinal cancer surgery: a systematic review.

BACKGROUND: Machine learning (ML) has seen an increase in application, and is an important element of a digital evolution. The role of ML within upper gastrointestinal surgery for malignancies has not been evaluated properly in the literature. Therefore, this systematic review aims to provide a comprehensive overview of ML applications within upper gastrointestinal surgery for malignancies. METHODS: A systematic search was performed in PubMed, EMBASE, Cochrane, and Web of Science. Studies were only included when they described machine learning in upper gastrointestinal surgery for malignancies. The Cochrane risk-of-bias tool was used to determine the methodological quality of studies. The accuracy and area under the curve were evaluated, representing the predictive performances of ML models. RESULTS: From a total of 1821 articles, 27 studies met the inclusion criteria. Most studies received a moderate risk-of-bias score. The majority of these studies focused on neural networks (n = 9), multiple machine learning (n = 8), and random forests (n = 3). Remaining studies involved radiomics (n = 3), support vector machines (n = 3), and decision trees (n = 1). Purposes of ML included predominantly prediction of metastasis, detection of risk factors, prediction of survival, and prediction of postoperative complications. Other purposes were predictions of TNM staging, chemotherapy response, tumor resectability, and optimal therapy. CONCLUSIONS: Machine Learning algorithms seem to contribute to the prediction of postoperative complications and the course of disease after upper gastrointestinal surgery for malignancies. However, due to the retrospective character of ML studies, these results require trials or prospective studies to validate this application of ML.

Trends in Distal Esophageal and Gastroesophageal Junction Cancer Care: The Dutch Nationwide Ivory Study.

OBJECTIVE: This study evaluated the nationwide trends in care and accompanied postoperative outcomes for patients with distal esophageal and gastro-esophageal junction cancer. SUMMARY OF BACKGROUND DATA: The introduction of transthoracic esophagectomy, minimally invasive surgery, and neo-adjuvant chemo(radio)therapy changed care for patients with esophageal cancer. METHODS: Patients after elective transthoracic and transhiatal esophagectomy for distal esophageal or gastroesophageal junction carcinoma in the Netherlands between 2007-2016 were included. The primary aim was to evaluate trends in both care and postoperative outcomes for the included patients. Additionally, postoperative outcomes after transthoracic and tran-shiatal esophagectomy were compared, stratified by time periods. RESULTS: Among 4712 patients included, 74% had distal esophageal tumors and 87% had adenocarcinomas. Between 2007 and 2016, the proportion of transthoracic esophagectomy increased from 41% to 81%, and neo-adjuvant treatment and minimally invasive esophagectomy increased from 31% to 96%, and from 7% to 80%, respectively. Over this 10-year period, postoperative outcomes improved: postoperative morbidity decreased from 66.6% to 61.8% ( P = 0.001), R0 resection rate increased from 90.0% to 96.5% (P <0.001), median lymph node harvest increased from 15 to 19 ( P <0.001), and median survival increased from 35 to 41 months ( P = 0.027). CONCLUSION: In this nationwide cohort, a transition towards more neo-adju-vant treatment, transthoracic esophagectomy and minimally invasive surgery was observed over a 10-year period, accompanied by decreased postoperative morbidity, improved surgical radicality and lymph node harvest, and improved survival.