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Background and Objective: Laparoscopic surgery offers the potential for video recording of the operation, which is important for technique evaluation, cognitive training, patient briefing and documentation. An effective way for video content representation is to extract a limited number of keyframes with semantic information. In this paper we present a novel method for keyframe extraction from individual shots of the operational video., Methods: The laparoscopic video was first segmented into video shots using an objectness model, which was trained to capture significant changes in the endoscope field of view. Each frame of a shot was then decomposed into three saliency maps in order to model the preference of human vision to regions with higher differentiation with respect to color, motion and texture. The accumulated responses from each map provided a 3D time series of saliency variation across the shot. The time series was modeled as a multivariate autoregressive process with hidden Markov states (HMMAR model). This approach allowed the temporal segmentation of the shot into a predefined number of states. A representative keyframe was extracted from each state based on the highest state-conditional probability of the corresponding saliency vector., Results: Our method was tested on 168 video shots extracted from various laparoscopic cholecystectomy operations from the publicly available Cholec80 dataset. Four state-of-the-art methodologies were used for comparison. The evaluation was based on two assessment metrics: Color Consistency Score (CCS), which measures the color distance between the ground truth (GT) and the closest keyframe, and Temporal Consistency Score (TCS), which considers the temporal proximity between GT and extracted keyframes. About 81% of the extracted keyframes matched the color content of the GT keyframes, compared to 77% yielded by the second-best method. The TCS of the proposed and the second-best method was close to 1.9 and 1.4 respectively., Conclusions: Our results demonstrated that the proposed method yields superior performance in terms of content and temporal consistency to the ground truth. The extracted keyframes provided highly semantic information that may be used for various applications related to surgical video content representation, such as workflow analysis, video summarization and retrieval., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: The purpose of this study was to describe the postoperative changes in lung function after pure open lobectomy for lung carcinoma., Methods: 30 patients (mean age 64 ± 7 years old, 16 men and 14 women) underwent a left or right lobectomy. They underwent spirometric pulmonary tests preoperatively, and at 1 and 6 months after the operation., Results: The average preoperative forced expiratory volume in 1 second (FEV1) was 2.55±0.62lt and the mean postoperative FEV1 at 1 and 6 months was 1.97 ± 0.59 L and 2.15±0.66 L respectively. The percentage losses for FEV1 were 22.7% and 15.4% after 1 and 6 months respectively. An average percentage increase of 9.4% for FEV1 was estimated at the time of 6 months in comparison with this of 1 month after the operation. The average preoperative forced vital capacity (FVC) was 3.17 ± 0.81 L and the mean postoperative FVC at 1 and 6 months after the operation was 2.50 ± 0.63 L and 2.72 ± 0.67 L respectively. The percentage losses for FVC were 21.1% and 14.2% after 1 and 6 months respectively. An average percentage increase of 8.7% was observed at the time period of 6 months in comparison with this of 1 month after the operation., Conclusion: Although, we observed a significant decrease in FEV1 and FVC after the operation, all patients were in excellent clinical status. FEV1 and FVC of 6 months were increased in comparison with the respective values of 1 month after the operation, but did not reach the preoperative values in any patient.

Thoracic incisions are the portals of choice for accessing thoracic organs. There are instances, however, that more than one incision are required at the same or a later stage, in order to access other, thoracic or extrathoracic, organs for more complicated procedures. Then again, a single thoracic incision may offer more than adequate access to extrathoracic organs and in selected cases becomes valuable surgical approach to organs of the upper abdomen or the contralateral hemithorax. The experience with this technique is discussed.

Behçet's disease is a chronic, recurrent, inflammatory disorder characterized by orogenital ulcers and skin lesions; serious manifestations also include ocular, large vessel, gastrointestinal and neurological involvement. Genetic and unknown environmental factors customise the wide clinical expression of the disease. Gastrointestinal involvement is not unusual, albeit with a highly variable frequency among different ethnic populations. However, given the fact that gastrointestinal symptoms such as reflux, bleeding, diarrhoea are common in the general population, their clinical significance needs to be carefully interpreted. Apart from mouth the ileocecal area is typically involved, but inflammatory and/or vasculitic lesions may affect any part of the gastrointestinal tract. Complications such as perforation carry high morbidity rates and even mortality. Herein, we review all available information pertinent to gastrointestinal involvement of Behçet's disease and discuss the published advances in evaluation and its empirical management, including anti-TNF biologic therapies.

Patients with antiphospholipid syndrome may develop various lung manifestations. The lung complications that have been described so far are pulmonary thromboembolic disease, pulmonary hypertension, acute respiratory distress syndrome, primary thrombosis of large and small lung vessels, diffuse alveolar haemorrhage, fibrosing alveolitis and postpartum syndrome. Clinicians should be aware of these conditions as in most of these cases, timely diagnosis and treatment is needed.

We present the case of an 18-year-old female with severe liver trauma after a motorcycle accident. Due to initial hemodynamic instability, fluid resuscitation and transfusion of two units of red packed cells was required. After stabilization, a CT scan was performed, showing grade V liver injuries according to the American Association for the Surgery of Trauma grading system. Angiography revealed multiple extravasations during the early arterial phase, as well as active extravasation from the proximal left hepatic artery in the late arterial phase. The patient was successfully treated by arterial embolization using metal microcoils, after which no further need for blood transfusion ensued. This report highlights that, in carefully selected cases, arterial embolization can improve the clinical condition of patients, reduce the need for blood transfusion and lessen the possibility of an operation, even if severe liver trauma has ensued.

We describe the case of a 67-year-old man who was referred for the management of severe mitral valve regurgitation and coronary artery disease. Further workup revealed a descending thoracic aorta aneurysm. He underwent mitral valve replacement with coronary artery bypass surgery and, at a second stage, endovascular stent graft repair of the descending thoracic aorta aneurysm.

We describe a woman with tetralogy of Fallot and pulmonary atresia, with a history of four previous cardiac operations, who decided to bear her own children. Under interdisciplinary counselling and the appropriate medical care, she underwent a successful vaginal delivery and had a healthy baby.

Postoperative chylothorax is a rare complication in thoracic surgery. There is considerable controversy concerning the management of chylothorax with some physicians favoring conservative treatment while others favor a surgical one. Considering the current surgical experience with VATS and by reviewing the problems and outcome of conservative management, the guidelines regarding timing of surgery in patients with chylous leak need to be revised.

Introduction: This article focuses on the effectiveness of virtual reality (VR) simulation training for intravenous (IV) cannulation. We analyzed the learning process in skills acquisition from groups with limited experience in comparison with the performance of experts., Methods: Novices (n = 20) and intermediates (n = 23) trained on nine IV cannulation scenarios with a high-fidelity VR simulator (Virtual IV). Another three scenarios were performed before and after training (pre- and postassessment). Pre-/postassessment was also undertaken by a group of 10 experts for comparative evaluation. Performance metrics included the completion time and an error score that was obtained after quantitative analysis of the errors committed during training. The learning curves were evaluated by recording the number of attempts required to successfully perform each training scenario. A performance was considered successful when the error score was below a predetermined threshold., Results: The learning curves of intermediates and novices demonstrated a clear plateau at the sixth and eighth scenario, respectively. These plateaus were reached after 15 (intermediates) and 23 (novices) attempts. There was a highly significant reduction in the time and errors between pre- and postassessment (P < 0.01). Before training, the performance (errors, time) of the three groups was significantly different to one another (novices: lowest, experts: highest, P < 0.05). After training, the performance of intermediates and novices was equivalent to that of the experts (P > 0.1). Intermediates committed fewer critical and more noncritical errors than novices, and vice versa (P < 0.05)., Conclusions: Simulation training enhanced the skills of inexperienced subjects significantly. The VR simulator demonstrated construct validity for three different levels of experience. The number of attempts over a series of equal difficulty scenarios provides a valuable alternative to the traditional measures of the learning curve.

Kawasaki disease (KD) is a vasculitis that affects mainly children of 6 months to 4 years old. It is important to be early recognised so as to limit the inflammatory cascade that may lead to aneurysmatic dilatations of coronary arteries. The causative agent of KD has not been still indentified and the aetiopathogenetic theories are based on epidemiologic, laboratory and histological data. The management of the disease is divided according to the clinical stage and patients' follow up should be continued for years after the disease onset. The exact period is determined by the risk level of the KD., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: Virtual reality (VR) simulators play a substantial role in modern medical education and have generated several performance parameters that are not always standardized and open to clear and easy interpretation. Consequently, our study objective was to investigate how these parameters contribute to the enhancement of key competencies in laparoscopic surgical skills., Methods: We recruited 20 residents and 8 experienced surgeons to participate in this study. The residents were trained on 5 basic tasks (4 of them at two difficulty levels) using a commercially available VR simulator. Study participants also performed an additional 3 complex tasks before and after training for assessment purposes. The experienced surgeons served as controls and so only performed the assessment tasks. Performance parameters were grouped to reflect errors in dexterity, safety, and technical skill. These errors, as well as the parameters of time and instrument velocity, were analyzed during training and assessment., Results: Performance for training tasks demonstrated notable learning curves for most of the parameters that were measured (ie, plateaus varied between the second and seventh VR training session). Velocity was influenced least by the training (3 of the 5 tasks), while time and dexterity were influenced most (all 5 tasks and for both difficulty levels). In the assessment tasks, technical skill was improved (P < .05) for some study participants, but this improvement was not demonstrated in all of the complex procedures tested (eg, bowel suturing). There was a significant improvement in safety (all 3 tasks; P < .05), and time to completion and dexterity (both of them in 2 tasks; P < .05). Experienced surgeons scored at a greater level than VR-trained residents in terms of time (all tasks; P < .05), safety and technical skill (bowel suturing; P < .05), as well as dexterity (adhesiolysis and bowel suturing; P < .05)., Conclusion: VR simulation training contributed markedly to the enhancement of key surgical competencies of residents. The proposed mapping of the simulator parameters may help program directors and trainees evaluate important competency domains during VR-based surgical training., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: To examine existing evidence, trends and possible factors that may have affected the incidence of papillary thyroid cancer (PTC) among patients undergoing thyroidectomies in an iodine-sufficient population of Greece., Study Design: All histology records from the patients who had undergone thyroid surgery at the Department of Surgery Laiko Hospital, Athens, Greece from January 1991 to December 2006 were retrospectively analyzed. Records were placed in a database which included patients' demographics, history, and medical condition, clinical and surgical parameters., Patients and Methods: One thousand four hundred and twenty-six patients (265 males and 1161 females) had undergone thyroidectomy during the above period of time. All surgeons favoured total thyroidectomy with resection of pro- and paratracheal lymph nodes. Thyroid tumors were classified according to the WHO classification system and were staged according to the TNM staging system., Results: In 278 patients, PTC was histologically diagnosed. From 1999 onwards, thyroid surgery shifted towards total thyroidectomy, while statistically significantly increased incidence of PTC and papillary microcarcinoma detection and decreased incidence of PTC greater than 10 mm detection in the whole population were noticed. Moreover, from 1999 onwards, smaller size of primary tumors, higher incidence of T1 tumors, lower incidence of T4 tumors, lower incidence of metastatically infiltrated peritracheal lymph nodes, higher incidence of stage I tumors and lower incidence of stage IV tumors were documented. Finally, a higher incidence of PTC in males, females and the whole population aged 51-70 years compared to the other age groups since 2003 was noticed., Conclusion: The increased incidence of PTC clearly correlated to the increased incidence of papillary microcarcinoma detection, reflecting the proportion for total thyroidectomy as well as changes in the diagnostic approach boosted by more careful pathological examination, rather than the effect of environmental factors such as the Chernobyl accident. Whether the Chernobyl accident has any predisposing effect on the increased incidence of PTC remains to be proven.

We report a 71-year-old man with severe mitral valve regurgitation in end stage heart failure intractable to medical treatment. He underwent mitral valve repair, coronary artery bypass grafting and tricuspid annuloplasty, and his postoperative course was uneventful with significant improvement of his symptoms. Mitral valve repair should be considered as a treatment modality in patients with cardiac failure and significant mitral valve regurgitation.

We describe the case of a young man who underwent anatomical correction of Tetralogy of Fallot in childhood. The patient developed severe pulmonary valve regurgitation, moderate tricuspid regurgitation and dilation of the right heart chambers. He underwent a redo sternotomy, replacement of the pulmonary valve and tricuspid annuloplasty with beating heart under extracorporeal circulation. Although this technique is more technically demanding, it avoids the use of cardioplegia and the complications of myocardial ischemia and reperfusion.