Robotic-assisted gastrectomy for gastric cancer: single Western center results

A robotic approach to abdominal surgery procedures may improve postoperative outcomes compared to either open or laparoscopic approaches. The role of robotics for gastric surgery, however, is still being evaluated. A retrospective review of the prospectively maintained database for robotic gastric surgery at University of Siena between 2011 and 2020 was conducted. Data regarding surgical procedures, early postoperative outcomes, and long-term follow-up were analyzed. 38 patients underwent robotic partial or total gastrectomy. Conversion to open occurred in two patients (5.2%) due to locally advanced disease as well as difficult identification of primary lesion. Postoperative morbidity was 13.1% while no postoperative mortality was registered. The mean length of operation was 358.6 (220–650) minutes and the mean number of retrieved lymph nodes was 35.8 (range: 5–73). The median OS of all population was 70.9 months. The median 5-year OS for the patients with positive nodes was worse than that of patients without metastatic lymph nodes [51.4 months (95% CI 35.5–67.4) vs. 79.5 months (95% CI 67.1–91.8); p = 0.079]. The interesting results including postoperative morbidity as well as mortality rate, the surgical outcomes, and the 5-year OS, were to be acceptable considering the data recorded by previous studies on robotic gastrectomy. This study demonstrated that robotic gastrectomy is feasible and can be safely performed. However, further follow-up and randomized clinical trials are required to confirm the role of a robotic approach in gastric cancer surgery

[Use of TachoSil® in the entero-colic anastomoses: results of an observational study].

Aim. In the last decade while many comparative studies examined hemostatic topics, adhesives and sealants, few clinical trials were made. We are focusing our attention particularly on TachoSil (R), and studying its efficacy on reducing the frequency of anastomotic leakage, thought to be one of the causes of prolonged periods of patients' hospitalization. Methods We examined 188 patients who underwent colorectal and enteric surgery at our department between January 2010 and March 2013. The efficacy of fibrin glue was evaluated on a cohort of patients at risk of anastomosis leakage. To test the relationship between the application of TachoSil (R) and the type of complications, a multiple logistic regression model was implemented. Fisher exact Test was used to compare the relations between two groups. The Mann-Whitney test was used to account for the days necessary for the follow-up of the patients in the various units participating in the study. Results. From the logistic regression model we can infer that TachoSil (R) is a highly protective factor though not statistically significant (OR=0.78; P>0.05). The results obtained analyzing the average days of patients hospitalization show a statistically significant decrease of such parameter in patients under treatment, especially those who underwent transverse colon resection (P<0.001). Conclusion. The results of this study show that TachoSil is a highly protective factor, but its efficacy is not statistically significant due to the small number of patients treated. It is important to call the attention to the reduced number of the hospitalization needed for the patients under treatment

Machine learning and monte carlo sampling for the probabilistic orienteering problem

The Probabilistic Orienteering Problem is a stochastic optimization problem about the delivery or goods to customers. Only a subset of the customer can be served in the given time, so the problem consists in the selection of the customers providing more revenues and in the optimization of a truck tour to serve them. The presence of the customers is however stochastic, and this has to be taken into account while evaluating the objective function of each solution. Due to the high computational complexity of such an objective function, Monte Carlo sampling method is used to estimate it in a fast way. There is one crucial parameter in a Monte Carlo sampling evaluator which is the number of samples to be used. More samples mean high precision, less samples mean high speed. An instance-dependent trade-off has to be found. The topic of this paper is a Machine Learning-based method to estimate the best number of samples, given the characteristics of an instance. Two methods are presented and compared from an experimental point of view. In particular, it is shown that a less intuitive and slightly more complex method is able to provide more precise estimations

The effect of learning curve on perioperative outcomes of robotic gastrectomy in two western high-volume centers

Introduction: To compare outcomes of robotic gastrectomy (RG) performed during the learning curve (P1) with those after its completion (P2). Methods: In this retrospective study, all consecutive RG patients (n&nbsp;=&nbsp;92) performed between 2008 and 2018 were included. Primary outcome was conversion rate. Results: D2 lymphadenectomies were more common in P2 (41, 97.6%) than P1 (41, 82.0%) (p&nbsp;=&nbsp;0.019). Conversions were 11 (22%) in P1 versus 2 (4.8%) in P2 (p&nbsp;=&nbsp;0.006). Postoperative morbidity was comparable between the groups. Median hospital stay was significantly shorter in P2. The only factor significantly associated with conversion was P2 (odds ratio = 0.18; 95% confidence interval, 0.04\u20130.85; p&nbsp;=&nbsp;0.039). The 5-year overall survival in P1 was 79.6% versus 79.7% in P2 (p&nbsp;=&nbsp;0.373). Conclusions: The learning curve affected operative and postoperative outcomes: during the learning curve, conversion to open surgery was significantly more frequent, the number of D2 was higher and patients were discharged earlier

CPTU correlations for Norwegian clays: an update

Geotechnical design in clay areas in Norway is mainly based on piezocone (CPTU) tests results. Strength and stiffness parameters are usually derived from CPTU parameters and empirical correlations. In order to improve geotechnical design practice (e.g. more cost-effective solutions) and to reduce risks related to the occurrence of catastrophic events (e.g. landslides, excavation failure) the Norwegian Geotechnical Institute (NGI) has recently updated its block sample database and worked on updating CPTU correlations for clays. This paper provides a short overview of NGI's block sample database consisting of 61 block samples data points collected from 17 Norwegian clay sites. Multiple regression analyses were used to evaluate possible correlations among CPTU parameters (e.g. excess pore pressure, Δu, net cone resistance, qnet, and effective cone resistance, qe), undrained shear strength (suC) and basic clay properties (e.g. overconsolidation ratio, OCR, plasticity, sensitivity). The target was to establish correlations characterized by low uncertainty. The most reliable assessment of undrained strength was obtained when using the Stress History and Normalized Soil Engineering Properties, SHANSEP, framework associated with the best estimate OCR profile extrapolated from the CPTU measurements. This well reflects the strong relation that suC has with OCR. Despite the high quality of the samples, high scatter was observed for some of the equations that compare cone factors and basic soil parameters. In addition to the natural variability of soil properties, other possible reason to justify the scatter is that even though the accuracy of CPTU probes has improved over the past decades, especially in terms of the ability to measure low values, the results can vary among the different manufacturers. Furthermore there may be several other soil parameters than the peak undrained strength that impacts the cone resistance, for instance stiffness and large strain behavior. Such factors can affect the correlation results

The effect of learning curve on perioperative outcomes of robotic gastrectomy in two western high-volume centers

Introduction: To compare outcomes of robotic gastrectomy (RG) performed during the learning curve (P1) with those after its completion (P2). Methods: In this retrospective study, all consecutive RG patients (n&nbsp;=&nbsp;92) performed between 2008 and 2018 were included. Primary outcome was conversion rate. Results: D2 lymphadenectomies were more common in P2 (41, 97.6%) than P1 (41, 82.0%) (p&nbsp;=&nbsp;0.019). Conversions were 11 (22%) in P1 versus 2 (4.8%) in P2 (p&nbsp;=&nbsp;0.006). Postoperative morbidity was comparable between the groups. Median hospital stay was significantly shorter in P2. The only factor significantly associated with conversion was P2 (odds ratio = 0.18; 95% confidence interval, 0.04–0.85; p&nbsp;=&nbsp;0.039). The 5-year overall survival in P1 was 79.6% versus 79.7% in P2 (p&nbsp;=&nbsp;0.373). Conclusions: The learning curve affected operative and postoperative outcomes: during the learning curve, conversion to open surgery was significantly more frequent, the number of D2 was higher and patients were discharged earlier