Robot-assisted endoscopic surgery

During the last three years, robot-assisted surgery systems are increasingly being applied in endoscopic surgery. They were introduced with the objective to overcome the challenges of standard endoscopic surgery. With the improvements in manipulation and visualisation that robotic-assistance offers, technologically complex procedures can be performed endoscopically and standard endoscopic procedures can be performed easier and with greater comfort to the surgeon. This serves the purpose of improvement of quality of care. The goal of this thesis was not only to assess the feasibility of various robot-assisted procedures both in experimental and clinical settings, but also to compare robot-assisted surgery to standard open and laparoscopic interventions. All studies aimed at assessing the benefits, challenges and potential pitfalls of using this new technology. In chapter 1 of this thesis, an introduction into robot-assisted surgery is provided. In chapters 2 to 5 of this thesis, the clinical experience with robot-assisted surgery at the University Medical Centre Utrecht is presented. This started with a series of 40 laparoscopic cholecystectomies as described in chapter 2. This relatively simple procedure was carried out repetitively in order to learn how to work with the, at that time, new technology of robotic assistance under accustomed circumstances. During these procedures only one conversion and no intra-operative complications occurred demonstrating it s safety. In our consecutive series of more complex procedures, as described in chapters 4 and 5, the number of conversions and complications was also low. Concerning the efficiency, operating times were comparable to times mentioned in literature and to times in our institute for procedures performed with standard endoscopic instrumentation. The critical remark that needs to be made, however, is the considerable set-up time we encountered in our series. The time needed to install and sterilely drape the equipment averaged 15 minutes. In chapter 3 we took a closer look at the time-loss and realised that robotic assistance in our institution will burden the operating schedules by approximately 20 minutes per procedure. This time-loss needs to be reduced in order to use robotic systems on a daily basis. In chapters 6 and 7 of this thesis, two challenging (robot-assisted) laparoscopic surgical procedures were compared to the standard open procedure in an experimental setting. It was noticed to be achievable to perform anastomoses with great ease and with a similar result as through the open approach, even though we had no previous experience with performing these procedures in a laparoscopic fashion. Furthermore, both robot-assisted retroperitoneal aortic replacements in pigs and ex-vivo intestinal anastomoses, as described in chapters 8 and 9, were compared to standard endoscopic surgery. For both procedures, clear advantages from robotic assistance were experienced. The vascular anastomoses were performed faster, with fewer errors and lower blood-loss with the use of the robot. A time/action analysis was performed for the intestinal anastomoses and it was demonstrated that even experienced laparoscopic surgeons performed better with use of the robot, even though they had no previous exposure to robot-assisted surgery. In conclusion, this thesis demonstrates that robot-assisted surgery is safe and efficient in both standard and complex endoscopic interventions. Robotic assistance was proven to offer distinct benefits over standard endoscopic surgery. To implement these systems in day-to-day surgery, the benefits will have to be demonstrated to outweigh the considerable investment of costs and time

Waiting Time from Diagnosis to Treatment has no Impact on Survival in Patients with Esophageal Cancer

Background Waiting time from diagnosis to treatment has emerged as an important quality indicator in cancer care. This study was designed to determine the impact of waiting time on long-term outcome of patients with esophageal cancer who are treated with neoadjuvant therapy followed by surgery or primary surgery. Methods Patients who underwent esophagectomy for esophageal cancer at the University Medical Center Utrecht between 2003 and 2014 were included. Patients treated with neoadjuvant therapy followed by surgery and treated with primary surgery were separately analyzed. The influence of waiting time on survival was analyzed using Cox proportional hazard analyses. Kaplan–Meier curves for short (<8 weeks) and long (≥8 weeks) waiting times were constructed. Results A total of 351 patients were included; 214 received neoadjuvant treatment, and 137 underwent primary surgery. In the neoadjuvant group, the waiting time had no impact on disease-free survival (DFS) [hazard ratio (HR) 0.96, 95 % confidence interval (CI) 0.88–1.04; p = 0.312] or overall survival (OS) (HR 0.96, 95 % CI 0.88–1.05; p = 0.372). Accordingly, no differences were found between neoadjuvantly treated patients with waiting times of <8 and ≥8 weeks in terms of DFS (p = 0.506) and OS (p = 0.693). In the primary surgery group, the waiting time had no impact on DFS (HR 1.03, 95 % CI 0.95–1.12; p = 0.443) or OS (HR 1.06, 95 % CI 0.99–1.13; p = 0.108). Waiting times of <8 weeks versus ≥8 weeks did not result in differences regarding DFS (p = 0.884) or OS (p = 0.374). Conclusions In esophageal cancer patients treated with curative intent by either neoadjuvant therapy followed by surgery or primary surgery, waiting time from diagnosis to treatment has no impact on long-term outcom

Логіко-лінгвістична модель як засіб відображення синтаксичних особливостей текстової інформації

Запропоновано використовувати логіко-лінгвістичні моделі як засіб відображення синтаксичних особливостей текстової інформації, перелічено та обґрунтовано правила їх формування, наведено алгоритм створення всіх складових таких моделей.Предложено использовать логико-лингвистические модели как способ отображения синтаксических особенностей текстовой информации, перечислены и обоснованы правила их формирования, приведен алгоритм создания всех составных таких моделей.It is suggested using a logico-linguistic model as a method of display the syntactical features of text information. There are listed and justified the rules for their forming and also are shown an algorithm of creation of all components of such models in this paper

Evaluation of the Implementation of FDG-PET/CT and Staging Laparoscopy for Gastric Cancer in The Netherlands

Background: The role of 18F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) and staging laparoscopy (SL) has increased in the preoperative staging of gastric cancer. Dutch national guidelines have recommended the use of FDG-PET/CT and SL for patients with locally advanced tumors since July 2016. Objective: The aim of this study was to evaluate the implementation of FDG-PET/CT and SL in The Netherlands. Methods: Between 2011 and 2018, all patients who underwent surgery for gastric cancer were included from the Dutch Upper GI Cancer Audit. The use of FDG-PET/CT and SL was evaluated before and after revision of the Dutch guidelines. Outcomes included the number of non-curative procedures (e.g. palliative and futile procedures) and the association of FDG-PET/CT and SL, with waiting times from diagnosis to the start of treatment. Results: A total of 3310 patients were analyzed. After July 2016, the use of FDG-PET/CT (23% vs. 61%; p < 0.001) and SL (21% vs. 58%; p < 0.001) increased. FDG-PET/CT was associated with additional waiting time to neoadjuvant therapy (4 days), as well as primary surgical treatment (20 days), and SL was associated with 8 additional days of waiting time to neoadjuvant therapy. Performing SL or both modalities consecutively in patients in whom it was indicated was not associated with the number of non-curative procedures. Conclusion

Factors influencing health-related quality of life after gastrectomy for cancer

_Aim:_ Insight in health-related quality of life (HRQoL) may improve clinical decision making and inform patients about the long-term effects of gastrectomy. This study aimed to evaluate and identify factors associated with HRQoL after gastrectomy. _Methods:_ This cross-sectional study used prospective databases from seven Dutch centers (2001–2015) including patients who underwent gastrectomy for cancer. Between July 2015 and November 2016, European Organization for Research and Treatment of Cancer HRQoL questionnaires QLQ-C30 and QLQ-STO22 were sent to all surviving patients without recurrence. The QLQ-C30 scores were compared to a Dutch reference population using a one-sample t test. Spearman’s rank test was used to correlate time after surgery to HRQoL, and multivariable linear regression was performed to identify factors associated with HRQoL. _Results:_ A total of 222 of 274 patients completed the questionnaires. Median follow-up was 29 months and 86.9% of patients had a follow-up >1 year. The majority of patients had undergone neoadjuvant treatme

Prognostic value of [18F]FDG PET radiomics to detect peritoneal and distant metastases in locally advanced gastric cancer: a side study of the prospective multicentre PLASTIC study

Aim: To improve identification of peritoneal and distant metastases in locally advanced gastric cancer using [18F]FDG-PET radiomics. Methods: [18F]FDG-PET scans of 206 patients acquired in 16 different Dutch hospitals in the prospective multicentre PLASTIC-study were analysed. Tumours were delineated and 105 radiomic features were extracted. Three classification models were developed to identify peritoneal and distant metastases (incidence: 21%): a model with clinical variables, a model with radiomic features, and a clinicoradiomic model, combining clinical variables and radiomic features. A least absolute shrinkage and selection operator (LASSO) regression classifier was trained and evaluated in a 100-times repeated random split, stratified for the presence of peritoneal and distant metastases. To exclude features with high mutual correlations, redundancy filtering of the Pearson correlation matrix was performed (r = 0.9). Model performances were expressed by the area under the receiver operating characteristic curve (AUC). In addition, subgroup analyses based on Lauren classification were performed. Results: None of the models could identify metastases with low AUCs of 0.59, 0.51, and 0.56, for the clinical, radiomic, and clinicoradiomic model, respectively. Subgroup analysis of intestinal and mixed-type tumours resulted in low AUCs of 0.67 and 0.60 for the clinical and radiomic models, and a moderate AUC of 0.71 in the clinicoradiomic model. Subgroup analysis of diffuse-type tumours did not improve the classification performance. Conclusion: Overall, [18F]FDG-PET-based radiomics did not contribute to the preoperative identification of peritoneal and distant metastases in patients with locally advanced gastric carcinoma. In intestinal and mixed-type tumours, the classification performance of the clinical model slightly improved with the addition of radiomic features, but this slight improvement does not outweigh the laborious radiomic analysis. </p