Background
Increased uptake of robotic surgery has led to interest in learning curves for robot‐assisted procedures. Learning curves, however, are often poorly defined. This systematic review was ...conducted to identify the available evidence investigating surgeon learning curves in robot‐assisted surgery.
Methods
MEDLINE, Embase and the Cochrane Library were searched in February 2018, in accordance with PRISMA guidelines, alongside hand searches of key congresses and existing reviews. Eligible articles were those assessing learning curves associated with robot‐assisted surgery in patients.
Results
Searches identified 2316 records, of which 68 met the eligibility criteria, reporting on 68 unique studies. Of these, 49 assessed learning curves based on patient data across ten surgical specialties. All 49 were observational, largely single‐arm (35 of 49, 71 per cent) and included few surgeons. Learning curves exhibited substantial heterogeneity, varying between procedures, studies and metrics. Standards of reporting were generally poor, with only 17 of 49 (35 per cent) quantifying previous experience. Methods used to assess the learning curve were heterogeneous, often lacking statistical validation and using ambiguous terminology.
Conclusion
Learning curve estimates were subject to considerable uncertainty. Robust evidence was lacking, owing to limitations in study design, frequent reporting gaps and substantial heterogeneity in the methods used to assess learning curves. The opportunity remains for the establishment of optimal quantitative methods for the assessment of learning curves, to inform surgical training programmes and improve patient outcomes.
Antecedentes
La aceptación creciente de la cirugía robótica ha generado interés en las curvas de aprendizaje para los procedimientos asistidos por robot. Sin embargo, las curvas de aprendizaje a menudo están mal definidas. Esta revisión sistemática se realizó para identificar la evidencia disponible en relación a las curvas de aprendizaje del cirujano en la cirugía asistida por robot.
Métodos
En Febrero de 2018, se realizaron búsquedas en MEDLINE, Embase y Cochrane Library, de acuerdo con las recomendaciones PRISMA, junto con búsquedas manuales de congresos clave y de revisiones ya existentes. Los artículos elegibles fueron aquellos que evaluaron las curvas de aprendizaje asociadas con la cirugía asistida por robot efectuada en pacientes.
Resultados
Las búsquedas bibliográficas identificaron 2.316 registros de los cuales 68 cumplían los criterios de elegibilidad y correspondían a 68 estudios primarios. De estos 68 estudios, 49 evaluaron las curvas de aprendizaje basadas en datos de pacientes de 10 especialidades quirúrgicas. Los 49 estudios eran todos estudios observacionales, en su mayoría de un solo brazo (35/49 (71%)) e incluían pocos cirujanos. Las curvas de aprendizaje mostraban una notable heterogeneidad, variando entre procedimientos, estudios y parámetros analizados. Los estándares de presentación de informes fueron generalmente deficientes, con solo 17/49 (35%) cuantificando la experiencia previa. Los métodos utilizados para evaluar la curva de aprendizaje fueron heterogéneos, a menudo carecían de validación estadística y usaban terminología ambigua.
Conclusión
Las estimaciones de la curva de aprendizaje estaban sujetas a una considerable incertidumbre, careciendo de evidencia robusta por las limitaciones en el diseño del estudio, lagunas de información en los artículos y heterogeneidad sustancial en los métodos utilizados para evaluar las curvas de aprendizaje. Queda pendiente establecer métodos cuantitativos óptimos para evaluar las curvas de aprendizaje, informar de los programas de formación quirúrgica y mejorar los resultados del paciente.
A broad systematic literature review was performed to characterize the current evidence base and appraise the methods used to measure and define learning curves for surgeons performing robot‐assisted surgery, taking a holistic, panspecialty view. The learning curve estimates identified are subject to considerable uncertainty, and robust evidence was often lacking due to limitations in study design and frequent reporting gaps. Thus, the opportunity remains for the establishment of optimal quantitative methods for the assessment of learning curves, which may inform surgical training programmes and improve patient outcomes.
Little consistency between studies
This paper presents lateral responses of an existing 2 × 2 pile group to advancement of side-by-side twin tunnels (with 1% volume loss) at various depths in dry sand using 3D centrifuge and numerical ...modelling. The tunnels were located near mid-depth of the pile shaft (test SS), next to (test TT) and below the toe (test BB) of the pile group. The largest and the smallest lateral movement of the pile cap was induced after first tunnelling in test TT and test SS, respectively. The shearing force was induced in piles as a reaction of pile deflection in tests TT and BB.
In densely built areas, the development of underground transportation systems often involves twin tunnels, which are sometimes unavoidably constructed adjacent to existing piled foundations. Because ...soil stiffness degrades with induced stress release and shear strain during tunnelling, it is vital to investigate the pile responses to subsequent tunnels after the first tunnel in a twin-tunnel transportation system. To gain new insights into single pile responses to side-by-side twin tunnelling in saturated stiff clay, a three-dimensional coupled-consolidation numerical parametric study is carried out. An advanced hypoplasticity (clay) constitutive model with small-strain stiffness is adopted. The effects of each tunnel depth relative to pile are investigated by simulating the twin tunnels either near the mid-depth of the pile shaft or adjacent to or below the pile toe. The model parameters are calibrated against centrifuge test results in stiff clay reported in literature. It is found the second tunnelling in each case resulted in larger settlement than that due to the first tunnelling with a maximum percentage difference of 175% in the case of twin tunnelling near the mid-depth of the shaft. This is because of the degradation of clay stiffness around the pile during the first tunnelling. Conversely, the first tunnelling-induced bending moment was reduced substantially during the second tunnelling. The most critical location of twin tunnels relative to the pile was found to be the tunnels below the pile toe. This is because the entire pile was located within the major influence zone of the twin tunnelling. Two distinct load transfer mechanisms can be identified in the pile, namely downward load transfer in case of tunnels near mid-depth of the pile shaft and next to the pile toe and upward load transfer in case of twin-tunnelling below the pile toe. These two transfer mechanisms can be useful for practitioner to assess the pile performance due to twin tunnelling.
In 1839 British East India Company captured the town of Karachi. After an effortless resistance from the locals the fort was conquered by the British commander sir Charles Napier. The village of ...Kolachi then was annexed to British India and the city was labeled as Karachi. With the British occupation a phase of new sophisticated architecture and development started. Before that the city was based upon the vernacular mud architecture. These developments resulted in an influx of economic migrants who helped in making Karachi as a multinational and a multicultural city. This paper investigates the architectural attributes that the historic core of the city offers. It also discusses the side by side development of the native and British towns. The paper also researches about the existing state of the architecture precedent of the British colonial past of the city and the urban blight occurred to them over time in various forms like vandalism, encroachments, illegal repairs, etc.
Purpose Open partial nephrectomy has emerged as the standard of care in the management of renal tumors smaller than 4 cm. While laparoscopic radical nephrectomy has been shown to be comparable to ...open radical nephrectomy with respect to long-term outcomes, important questions remain unanswered regarding the oncological efficacy of laparoscopic partial nephrectomy. We examined the practice patterns and pathological outcomes following laparoscopic partial nephrectomy. Materials and Methods A survey was sent to academic medical centers in the United States and in Europe performing laparoscopic partial nephrectomy. The total number of laparoscopic partial nephrectomies, positive margins, indications for intraoperative frozen biopsy as well as tumor size and position were queried. Results Surveys suitable for analysis were received from 17 centers with a total of 855 laparoscopic partial nephrectomy cases. Mean tumor size was 2.7 cm (±0.6). There were 21 cases with positive margins on final pathology, giving an overall positive margin rate of 2.4%. Intraoperative frozen sections were performed selectively at 10 centers based on clinical suspicion of positive margins on excised tumor. Random biopsies were routinely performed on the resection bed at 5 centers. Frozen sections were never performed at 2 centers. Of the 21 cases with positive margins 14 underwent immediate radical nephrectomy based on the frozen section and 7 were followed expectantly. Conclusions Early experience with laparoscopic partial nephrectomy in this multicenter study demonstrates oncological efficacy comparable to that of open partial nephrectomy with respect to the incidence of positive margins. The practice of intraoperative frozen sections varied among centers and is not definitive in guiding the optimal surgical treatment.
The contractor is the primary stakeholder in materializing a project concept. For the successful completion of any project, it is compulsory for the contractor to have relevant experience. The ...selection of the appropriate contractor depends on various criteria. This study aims to study these selection criteria. Based on 71 questionnaire forms received from representatives of contractor, consultant and client firms involved in execution works of construction activities it is found that quality, bid amount, technical capability, financial stability, and experience are five commonly adopted criteria for contractor selection in construction works in Pakistan. On the other hand, quality, technical capability, financial stability, equipment availability, and management capability are reported as the top five effective criteria for appropriate contractor selection for any construction project.
Laparoscopy for urological surgery is a relatively recent surgical innovation. Some centres have substantial experience of single operations, but very few have experience with a comprehensive range. ...Our programme began with nephrectomy and pyeloplasty, and has expanded to provide for a living related kidney donor programme and for other procedures usually conducted open. Recently, it has included prostate and bladder cancer surgery. The learning curve and implications for anaesthesia are described on the basis of the experience of one anaesthetist with 124 patients. Perioperative care issues, in common with other abdominal laparoscopic procedures, relate to operating positions, the consequences of carbon dioxide under pressure in the abdomen and postoperative analgesia. There is only a small requirement for regional anaesthesia supplementation and invasive analgesia. The corporate laparoscopic cholecystectomy experience was used as the foundation for anaesthesia and to delineate specific organ system issues and any interventions. Significant differences were found in the spectrum of the urological patient population and comorbidity, notably renal function or dysfunction, and complications.
The present study reports the synthesis of novel hedgehog-like NiO nanostructures via hydrothermal method using l-cysteine as a structure directing agent. The as-synthesized hedgehog-like NiO ...nanostructures were characterized by scanning electron microscopy (SEM), X-ray photoelectron microscopy (XPS) X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques for morphological, compositional and structural studies respectively. The prepared NiO nanostructures were applied for the design and engineering of non-enzymatic glucose sensor in the alkaline medium. The electrode material for glucose sensing based on the hedgehog-like NiO nanostructures demonstrated extremely high electrochemical response with high sensitivity (1052.8μAmM−1cm−2), low detection limit (LOD) (1.2μM), high selectivity, wide linear range (0.1–5.0μM) (R2=0.9982) and the outstanding reproducibility. A plausible growth mechanism has been proposed to explain the formation process of the hedgehog-like NiO nanostructures. The excellent sensing performance can be attributed to the unique surface architectures, which enhanced the electron transfer rate and the molecular approach during the electrochemical sensing of glucose. Furthermore, the sensor showed excellent performance for the quantification of glucose in real blood sera reflecting universal nature of the presented glucose sensor.
This study analyzes the response of various hydrological parameters and future water availability against anticipated climate variations in snow dominated alpine catchment in Austria. The parameters ...assessed are base flow, environmental flow, total flow, evapotranspiration, and snow cover duration. The distributed hydrological modeling system PREVAH is developed to assess the impacts through the combination of various climate change scenarios produced under the framework of the European project PRUDENCE. The model results clearly indicate an apparent shift from observed trends in monthly, seasonal and annual values. The mean annual changes observed by all model scenarios range between 45% to 60% decrease in snow cover duration, 15% to 20% increase in evapotranspiration, 5% to 15% decrease in base flow, and 15% to 25% decrease in total runoff values. However, mean annual changes observed in available water are marginal, just ranging from -3% to +2%. All regional model projections show more or less the same identical pattern of changes in analyzed parameters.
Purpose We assessed the efficacy of a prototype laparoscopic topical cooling device. The aim of regional renal hypothermia in laparoscopic surgery is to limit ischemic injury and extend safe ...operative time. A reliable model for assessing renal ischemic injury exists in the field of nonheart beating donor renal transplantation. Hypothermic machine perfusion allows calculation of the pressure flow index and measurement of glutathione S-transferase in the perfusate. These parameters allow accurate assessment of the extent of renal damage. Materials and Methods The device incorporates a 2-layer cooling bag and coolant circuit. The system achieves hypothermia by circulating coolant across the surface of the kidney. Using 10 pigs individual kidneys were subjected to periods of renal ischemia with or without device in situ cooling. Each kidney was then machine perfused and assessed using nonheart beating donor viability criteria. Results The best performance of the device achieved a renal parenchymal temperature of 15C in 11.2 minutes (mean ± SD 21.4 ± 8.42). In the warm ischemia groups significant deterioration of pressure flow index compared to controls occurred by 60 minutes (p = 0.0001). In cooled kidneys at 60 minutes the mean pressure flow index was not significantly different from that in controls. Greater mean glutathione S-transferase measurements were associated with the warm ischemia groups. Conclusions Our study reinforces the efficacy of topical renal cooling in the laparoscopic setting. We report the use of assessment techniques capable of accurate quantitative measurement of renal injury in an animal model. Our cooling device is currently undergoing further development to enhance its efficiency.
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