This comparative study shows that HALS simplifies difficult intraoperative situations, reducing the need for conversion. Although it is a more aggressive procedure, HALS preserves the features of a minimally invasive approach, maintains all of the oncological features of conventional laparoscopic surgery, and does not increase the cost. HALS should therefore be considered as a useful adjunct when difficult situations arise during conventional laparoscopic colectomy.

The growing capacity to process and store animal tracks has spurred the development of new methods to segment animal trajectories into elementary units of movement. Key challenges for movement trajectory segmentation are to (i) minimize the need of supervision, (ii) reduce computational costs, (iii) minimize the need of prior assumptions (e.g. simple parametrizations), and (iv) capture biologically meaningful semantics, useful across a broad range of species. We introduce the Expectation-Maximization binary Clustering (EMbC), a general purpose, unsupervised approach to multivariate data clustering. The EMbC is a variant of the Expectation-Maximization Clustering (EMC), a clustering algorithm based on the maximum likelihood estimation of a Gaussian mixture model. This is an iterative algorithm with a closed form step solution and hence a reasonable computational cost. The method looks for a good compromise between statistical soundness and ease and generality of use (by minimizing prior assumptions and favouring the semantic interpretation of the final clustering). Here we focus on the suitability of the EMbC algorithm for behavioural annotation of movement data. We show and discuss the EMbC outputs in both simulated trajectories and empirical movement trajectories including different species and different tracking methodologies. We use synthetic trajectories to assess the performance of EMbC compared to classic EMC and Hidden Markov Models. Empirical trajectories allow us to explore the robustness of the EMbC to data loss and data inaccuracies, and assess the relationship between EMbC output and expert label assignments. Additionally, we suggest a smoothing procedure to account for temporal correlations among labels, and a proper visualization of the output for movement trajectories. Our algorithm is available as an R-package with a set of complementary functions to ease the analysis.

The development of operative laparoscopic surgery is linked to advances in ancillary surgical instrumentation. Ultrasonic energy devices avoid the use of electricity and provide effective control of small- to medium-sized vessels. Bipolar computer-controlled electrosurgical technology eliminates the disadvantages of electrical energy, and a mechanical blade adds a cutting action. This instrument can provide effective hemostasis of large vessels up to 7 mm. Such devices significantly increase the cost of laparoscopic procedures, however, and the amount of evidence-based information on this topic is surprisingly scarce. This study compared the effectiveness of three different energy sources on the laparoscopic performance of a left colectomy. The trial included 38 nonselected patients with a disease of the colon requiring an elective segmental left-sided colon resection. Patients were preoperatively randomized into three groups. Group I had electrosurgery; vascular dissection was performed entirely with an electrosurgery generator, and vessels were controlled with clips. Group II underwent computer-controlled bipolar electrosurgery; vascular and mesocolon section was completed by using the 10-mm Ligasure device alone. In group III, 5-mm ultrasonic shears (Harmonic Scalpel) were used for bowel dissection, vascular pedicle dissection, and mesocolon transection. The mesenteric vessel pedicle was controlled with an endostapler. Demographics (age, sex, body mass index, comorbidity, previous surgery and diagnoses requiring surgery) were recorded, as were surgical details (operative time, conversion, blood loss), additional disposable instruments (number of trocars, EndoGIA charges, and clip appliers), and clinical outcome. Intraoperative economic costs were also evaluated. End points of the trial were operative time and intraoperative blood loss, and an intention-to-treat principle was followed. The three groups were well matched for demographic and pathologic features. Surgical time was significantly longer in patients operated on with conventional electrosurgery vs the Harmonic Scalpel or computed-based bipolar energy devices. This finding correlated with a significant reduction in intraoperative blood loss. Conversion to other endoscopic techniques was more frequent in Group I; however, conversion to open surgery was similar in all three groups. No intraoperative accident related to the use of the specific device was observed in any group. Immediate outcome was similar in the three groups, without differences in morbidity, mortality, or hospital stay. Analysis of operative costs showed no significant differences between the three groups. High-energy power sources specifically adapted for endoscopic surgery reduce operative time and blood loss and may be considered cost-effective when left colectomy is used as a model.

The laparoscopic treatment of large paraesophageal and mixed hiatal hernias is not only feasible and safe but also offers a good quality of life on a midterm basis. However, the anatomic and functional recurrence rate is high. The next step is to identify the subset of patients who are at risk of failure and to establish technical alternatives that would ensure the durability of the repair.