Explore the vast range of titles available.

BackgroundCurrent evaluation methods for robotic-assisted surgery (ARCS or GEARS) are limited to 5-point Likert scales which are inherently time-consuming and require a degree of subjective scoring. In this study, we demonstrate a method to break down complex robotic surgical procedures using a combination of an objective cumulative sum (CUSUM) analysis and kinematics data obtained from the da Vinci® Surgical System to evaluate the performance of novice robotic surgeons.MethodsTwo HPB fellows performed 40 robotic-assisted hepaticojejunostomy reconstructions to model a portion of a Whipple procedure. Kinematics data from the da Vinci® system was recorded using the dV Logger® while CUSUM analyses were performed for each procedural step. Each kinematic variable was modeled using machine learning to reflect the fellows’ learning curves for each task. Statistically significant kinematics variables were then combined into a single formula to create the operative robotic index (ORI).ResultsThe inflection points of our overall CUSUM analysis showed improvement in technical performance beginning at trial 16. The derived ORI model showed a strong fit to our observed kinematics data (R2 = 0.796) with an ability to distinguish between novice and intermediate robotic performance with 89.3% overall accuracy.ConclusionsIn this study, we demonstrate a novel approach to objectively break down novice performance on the da Vinci® Surgical System. We identified kinematics variables associated with improved overall technical performance to create an objective ORI. This approach to robotic operative evaluation demonstrates a valuable method to break down complex surgical procedures in an objective, stepwise fashion. Continued research into objective methods of evaluation for robotic surgery will be invaluable for future training and clinical implementation of the robotic platform.

Background Society consensus guidelines are commonly used to guide management of pancreatic cystic neoplasms (PCNs). However, downsides of these guidelines include unnecessary surgery and missed malignancy. The aim of this study was to use computed tomography (CT)-guided deep learning techniques to predict malignancy of PCNs. Materials and Methods Patients with PCNs who underwent resection were retrospectively reviewed. Axial images of the mucinous cystic neoplasms were collected and based on final pathology were assigned a binary outcome of advanced neoplasia or benign. Advanced neoplasia was defined as adenocarcinoma or intraductal papillary mucinous neoplasm with high-grade dysplasia. A convolutional neural network (CNN) deep learning model was trained on 66% of images, and this trained model was used to test 33% of images. Predictions from the deep learning model were compared to Fukuoka guidelines. Results Twenty-seven patients met the inclusion criteria, with 18 used for training and 9 for model testing. The trained deep learning model correctly predicted 3 of 3 malignant lesions and 5 of 6 benign lesions. Fukuoka guidelines correctly classified 2 of 3 malignant lesions as high risk and 4 of 6 benign lesions as worrisome. Following deep learning model predictions would have avoided 1 missed malignancy and 1 unnecessary operation. Discussion In this pilot study, a deep learning model correctly classified 8 of 9 PCNs and performed better than consensus guidelines. Deep learning can be used to predict malignancy of PCNs; however, further model improvements are necessary before clinical use.

Introduction Studies have shown that for patients with hilar cholangiocarcinoma (HC), survival is associated with negative resection margins (R0). This requires increasingly proximal resection, putting patients at higher risk for complications, which may delay chemotherapy. For patients with microscopically positive resection margins (R1), the use of modern adjuvant therapies may offset the effect of R1 resection. Methods Patients at our institution with HC undergoing curative-intent resection between January 2008 and July 2019 were identified by retrospective record review. Demographic data, operative details, tumor characteristics, postoperative outcomes, recurrence, survival, and follow-up were recorded. Patients with R0 margin were compared to those with R1 margin. Patients with R2 resection were excluded. Results Seventy-five patients underwent attempted resection with 34 (45.3%) cases aborted due to metastatic disease or locally advanced disease. Forty-one (54.7%) patients underwent curative-intent resection with R1 rate of 43.9%. Both groups had similar rates of adjuvant therapy (56.5% vs. 61.1%, P = .7672). Complication rates and 30 mortality were similar between groups (all P > .05). Both groups had similar median recurrence-free survival (R0 29.2 months vs. R1 27.8 months, P = .540) and median overall survival (R0 31.2 months vs. R1 38.8 months, P = .736) with similar median follow-up time (R0 29.9 months vs. R1 28.5 months, P = .8864). Conclusions At our institution, patients undergoing hepatic resection for HC with R1 margins have similar recurrence-free and overall survival to those with R0 margins. Complications and short-term mortality were similar. This may indicate that with use of modern adjuvant therapies obtaining an R0 resection is not an absolute mandate.

As bariatric surgery increases, there is a growing population of patients with biliary obstruction and anatomy which precludes transoral access through endoscopic retrograde cholangiopancreatography (ERCP). Minimally invasive transgastric ERCP (TG-ERCP) offers a feasible alternative for the treatment. A retrospective review was performed of all patients who underwent laparoscopic or robotic-assisted TG-ERCP between 2010 and 2017. Chart abstraction collected demographics, procedural details, success rate, and postoperative outcomes. Forty patients were identified, of which 38 cases were performed laparoscopically and two robotically. Median operative time was 163 minutes, with an estimated blood loss of 50 cc. TG-ERCP was performed successfully in 36 cases (90%); sphincterotomy was completed in 35 patients (97%). Sixty per cent already had a cholecystectomy; in the remaining patients, it was performed concurrently. Major complications included stomach perforation (n = 1), pancreatitis (n = 3), and anemia requiring transfusion (n = 2). In patients with biliary obstruction and anatomy not suitable for ERCP, TG-ERCP can be performed in a minimally invasive fashion, with a high rate of technical success and low morbidity. We describe a stepwise, reproducible technique because it is an essential tool for the shared armamentarium of endoscopists and surgeons.

Clinical outcomes for the overall severe aortic stenosis (AS) patient population are not well described because those medically managed are not included in procedural registries, and AS severity is not identifiable from administrative data. We aim to assess whether transcatheter aortic valve implantation (TAVI) availability has been associated with overall changes in survival for the whole AS patient population. This is important because patients with AS in real-world practice may differ from those included in randomized controlled trials, potentially attenuating the purported treatment efficacy estimated in trials. Classic severe AS patients (mean gradient ≥40 mmHg) were identified from an echocardiography database. Survival was defined as time since severe AS diagnosis until death. We first compared survival among all patients before and after TAVI availability in 2008. To further understand mechanism, we then assessed whether any survival changes were attributable to TAVI with extended Cox regression models comparing survival among TAVI, surgical aortic valve replacement, and medically managed patients. 3663 classic severe AS patients were included in the study. Median survival years for all patients were greater during the TAVI-era than Pre-TAVI-era (>11.5 vs 6.8, 5-year-HR = 0.8, time-varying effect p <0.0001), and increased median survival was greatest for patients age 65 to74 (>11.5 vs 9.5, 5-year-HR = 0.7, time-varying effect p = 0.045). TAVI patients age 65 to 74 had the lowest risk of death compared to medically managed patients (HR = 0.2, 95% CI = [0.1, 0.3], p <0.0001). In conclusion, in the TAVI-era, overall survival for patients with severe AS has doubled. This improvement is most marked for patients 65 to 74 years of age.

An ecological threshold is the point at which a comparatively small environmental change triggers an abrupt and disproportionately large ecological response. In the face of accelerating climate change, there is concern that abrupt ecosystem transformations will become more widespread as critical ecological thresholds are crossed. There has been ongoing debate, however, regarding the prevalence of ecological thresholds across the natural world. While ecological thresholds are ubiquitous in some ecosystems, thresholds have been difficult to detect in others. Some studies have even concluded that threshold responses are uncommon in the natural world and overly emphasized in the ecological literature. As ecologists who work in ecosystems chronically exposed to high abiotic stress, we consider ecological thresholds and ecosystem transformations to be critical concepts that can greatly advance understanding of ecological responses to climate change and inform ecosystem management. But quantifying ecological thresholds can be challenging, if not impossible, without data that are strategically collected for that purpose. Here, we present a conceptual framework built upon linkages between abiotic stress, climate‐driven ecological threshold responses, and the risk of ecosystem transformation. We also present a simple approach for quantifying ecological thresholds across abiotic stress gradients. We hypothesize that climate‐driven threshold responses are especially influential in ecosystems chronically exposed to high abiotic stress, where autotroph diversity is low and foundation species play a prominent ecological role. Abiotic conditions in these environments are often near physiological tolerance limits of foundation species, which means that small abiotic changes can trigger landscape‐level ecological transformations. Conversely, the alleviation of stress near thresholds can allow foundation species to thrive and spread into previously inhospitable locations. We provide examples of this climate‐driven threshold behavior from four high‐stress environments: coastal wetlands, coral reefs, drylands, and alpine ecosystems. Our overarching aim in this review is to clarify the strong relationships between abiotic stress, climate‐driven ecological thresholds, and the risk of ecosystem transformation under climate change.

•Millennial learners often find traditional didactic-based learning challenging.•Flipped classroom models (FCM) reverse the traditional teaching structure.•FCM was associated with higher ABSITE scores in surgery residents.

Sea-level rise rates are predicted to surpass rates of wetland vertical adjustment in the coming decades in many areas, increasing the potential for wetland submergence. Information on where wetland migration is possible can help natural resource managers for planning land acquisition or enhancing habitat connectivity to bolster adaptation of coastal wetlands to rising seas. Elevation-based models of wetland migration are often hampered with uncertainty associated with ground surface elevation, current water levels (i.e., tides and extreme water levels), and future water levels from sea-level rise. Here, we developed an approach that involved digital elevation model error reduction and the use of Monte Carlo simulations that utilize uncertainty assumptions regarding elevation error, contemporary water levels, and future sea levels to identify potential wetland migration areas. Our analyses were developed for Duvall and Nassau Counties in northeastern Florida (USA). We focus on the migration of regularly oceanic-flooded wetlands (i.e., flooded by oceanic water daily) and irregularly oceanic-flooded wetlands (i.e., flooded by oceanic water less frequently than daily). For two relative sea-level rise scenarios based on the 0.5 m and the 1.5 m global mean sea-level rise scenarios, we quantified migration by wetland flooding frequency class and identified land cover and land use types that are vulnerable to future exposure to oceanic waters. The variability in total coverage and relative coverage of wetland migration from our results highlights how topography and accelerated sea-level rise interact. Our wetland migration results communicate uncertainty by showing flooding frequency class as probabilistic outputs.

Calcific aortic stenosis (AS) is one of the most common acquired valvular heart diseases in industrialized nations. It is a slowly progressive disease and with the aging population, the prevalence of AS is expected to increase. Doppler echocardiography is used to classify patients based on severity of stenosis. Research efforts on how to better identify and risk-assess these patients are currently underway using advanced imaging modalities and serum biomarkers. Thus far, medications for AS prevention have been unsuccessful. As technology progresses, the assessment of AS will transition from one heavily weighed on echocardiographic gradients to one of active surveillances with multimodality imaging, serum biomarkers and genetic assessment.

The essential multidisciplinary guide for the prevention and management of vascular injury from master skull base surgeons Vascular injury is the most significant source of morbidity or mortality during skull base surgery, regardless of the surgical approach. While skull base approaches always placed arteries and veins at risk, newer endoscopic endonasal approaches have introduced new challenges for the prevention and management of vascular injury. Greater anatomic knowledge, additional surgical options, improved instrumentation, advances in interventional neuroradiology, and enhanced training all contribute to successful outcomes. Vascular Challenges in Skull Base Surgery by renowned skull base experts Paul Gardner, Carl Snyderman, Brian Jankowitz, and distinguished contributors, fills a gap in the literature, with invaluable guidance on managing rare but potentially catastrophic surgical complications. The full range of surgical approaches to the anterior, middle, and posterior cranial fossae are covered in 22 chapters. Diverse topics encompass open and endoscopic endonasal surgical approaches, endovascular techniques including balloon test occlusion and embolization, and standard and alternative bypass procedures. The last three chapters discuss venous considerations, neurophysiologic monitoring, and the role of training and simulation in vascular injury prevention. Key learning points, illustrated discussion of relevant anatomy, and tips and tricks are targeted at helping skull base surgeons leverage practical strategies to improve patient outcomes. Key Highlights * An impressive group of expert, highly-experienced surgeons share firsthand knowledge * Insightful analyses of root causes and clinical pearls provide indispensable prevention tactics * High-quality images and videos enhance visual understanding of surgical anatomy and techniques Trainees and practicing skull base surgeons will greatly benefit from the collective knowledge and evidence-based injury avoidance strategies shared by authors who have learned to master the art of skull base surgery.