Technical-skills training in the 21st century.
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Clinical Competence↗
Biomedical subjects
Rajesh Aggarwal
Publications and source records attributed to Rajesh Aggarwal.
Cellular and molecular determinants of altered Ca2+ handling in the failing rabbit heart: primary defects in SR Ca2+ uptake and release mechanisms.
Myocytes from the failing myocardium exhibit depressed and prolonged intracellular Ca(2+) concentration ([Ca(2+)](i)) transients that are, in part, responsible for contractile dysfunction and unstable repolarization. To better understand the molecular basis of the aberrant Ca(2+) handling in heart failure (HF), we studied the rabbit pacing tachycardia HF model. Induction of HF was associated with action potential (AP) duration prolongation that was especially pronounced at low stimulation frequencies. L-type calcium channel current (I(Ca,L)) density (-0.964 +/- 0.172 vs. -0.745 +/- 0.128 pA/pF at +10 mV) and Na(+)/Ca(2+) exchanger (NCX) currents (2.1 +/- 0.8 vs. 2.3 +/- 0.8 pA/pF at +30 mV) were not different in myocytes from control and failing hearts. The amplitude of peak [Ca(2+)](i) was depressed (at +10 mV, 0.72 +/- 0.07 and 0.56 +/- 0.04 microM in normal and failing hearts, respectively; P < 0.05), with slowed rates of decay and reduced Ca(2+) spark amplitudes (P < 0.0001) in myocytes isolated from failing vs. control hearts. Inhibition of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA)2a revealed a greater reliance on NCX to remove cytosolic Ca(2+) in myocytes isolated from failing vs. control hearts (P < 0.05). mRNA levels of the alpha(1C)-subunit, ryanodine receptor (RyR), and NCX were unchanged from controls, while SERCA2a and phospholamban (PLB) were significantly downregulated in failing vs. control hearts (P < 0.05). alpha(1C) protein levels were unchanged, RyR, SERCA2a, and PLB were significantly downregulated (P < 0.05), while NCX protein was significantly upregulated (P < 0.05). These results support a prominent role for the sarcoplasmic reticulum (SR) in the pathogenesis of HF, in which abnormal SR Ca(2+) uptake and release synergistically contribute to the depressed [Ca(2+)](i) and the altered AP profile phenotype.
Abdomen↗
A competency-based virtual reality training curriculum for the acquisition of laparoscopic psychomotor skill.
BACKGROUND: Studies have demonstrated the beneficial effect of training novice laparoscopic surgeons using virtual reality (VR) simulators, although there is still no consensus regarding an optimal VR training curriculum. This study aims to establish and validate a structured VR curriculum to provide an evidence-based approach for laparoscopic training programmes. METHODS: The minimally invasive VR simulator (MIST-VR) has 12 abstract laparoscopic tasks, each at 3 graduated levels of difficulty (easy, medium, and hard). Twenty medical students completed 2 sessions of all tasks at the easy level, 10 sessions at the medium level, and finally 5 sessions of the 2 most complex tasks at the hard level. At the medium level, subjects were randomized into 2 equal groups performing either all 12 tasks (group A) or the 2 most complex tasks (group B). Performance was measured by time taken, path length, and errors for each hand. The results were compared between groups, and to those of 10 experienced laparoscopic surgeons. RESULTS: Baseline performance of both groups was similar at the easy level. At the medium level, learning curves for all 3 parameters reached plateau at the second (group A, P < .05) and sixth (group B, P < .05) repetitions. Performance at the hard level was similar between the 2 groups, and all achieved the pre-set expert criteria. CONCLUSION: A graduated laparoscopic training curriculum enables trainees to familiarise, train and be assessed on laparoscopic VR simulators. This study can aid the incorporation of VR simulation into established surgical training programmes.
Adolescent↗
Training junior operative residents in laparoscopic suturing skills is feasible and efficacious.
BACKGROUND: Laparoscopic suturing has been regarded as an advanced operative task, and courses to develop this skill are aimed at senior trainees and consultants. This study evaluates the role of laparoscopic suturing courses in the modern operative training curriculum. METHODS: The performance of 9 senior operative trainees (course A) was compared to that of 14 junior operative trainees (course B) at identical, 2-day laparoscopic suturing courses. Pre- and post-course assessments measured time taken, dexterity, and quality for the placement of 1 intracorporeal suture on synthetic bowel. Post-course data was compared to the performance of a group of 6 experts. RESULTS: The median number of laparoscopic procedures carried out unassisted was 130 for surgeons on course A, and 0 for those on course B. At the pre-course assessment, senior trainees (course A) were significantly faster, more dexterous, and had higher checklist scores then those on course B. Both groups had improved significantly by the end of each the course. Post-course comparison between the 2 groups showed equivalent path length and checklist scores, although group A remained faster (P = .003) and made fewer movements (P = .033). Senior trainees had similar performance data to the group of expert surgeons, although this was not the case for junior trainees. CONCLUSIONS: Endoscopic suturing is a task that can be learned by operative trainees during short skills courses, regardless of baseline laparoscopic experience. Skills training in laparoscopic suturing should thus not be reserved only for those contemplating advanced laparoscopic operation.
General Surgery↗
An evidence-based virtual reality training program for novice laparoscopic surgeons.
OBJECTIVE: To develop an evidence-based virtual reality laparoscopic training curriculum for novice laparoscopic surgeons to achieve a proficient level of skill prior to participating in live cases. SUMMARY BACKGROUND DATA: Technical skills for laparoscopic surgery must be acquired within a competency-based curriculum that begins in the surgical skills laboratory. Implementation of this program necessitates the definition of the validity, learning curves and proficiency criteria on the training tool. METHODS: The study recruited 40 surgeons, classified into experienced (performed >100 laparoscopic cholecystectomies) or novice groups (<10 laparoscopic cholecystectomies). Ten novices and 10 experienced surgeons were tested on basic tasks, and 11 novices and 9 experienced surgeons on a procedural module for dissection of Calot triangle. Performance of the 2 groups was assessed using time, error, and economy of movement parameters. RESULTS: All basic tasks demonstrated construct validity (Mann-Whitney U test, P < 0.05), and learning curves for novices plateaued at a median of 7 repetitions (Friedman's test, P < 0.05). Expert surgeons demonstrated a learning rate at a median of 2 repetitions (P < 0.05). Performance on the dissection module demonstrated significant differences between experts and novices (P < 0.002); learning curves for novice subjects plateaued at the fourth repetition (P < 0.05). Expert benchmark criteria were defined for validated parameters on each task. CONCLUSION: A competency-based training curriculum for novice laparoscopic surgeons has been defined. This can serve to ensure that junior trainees have acquired prerequisite levels of skill prior to entering the operating room, and put them directly into practice.
Benchmarking↗
Is collagen a good banding material for outlet control of vertical gastroplasty? Preliminary study in pigs.
BACKGROUND: To maintain the long-term effects of a gastric bariatric operation, bands are often placed to control the restriction. Erosion into the gastric wall by these devices remains a problem. A soft resiliant prosthesis of animal origin, constituted by a network of non-absorbable collagen fibres, may be a solution to this problem. This study assessed, in a porcine model, the histological reaction of the gastric wall following apposition of a band of porcine collagen (Pelvicol, Bard). METHODS: 15 female pigs weighing on average 21 kg underwent vertical banded gastroplasty (VBG). Stoma control was achieved with a band of porcine collagen (2 cm wide, 7 cm long and 2 mm thick). The pigs were sacrificed 1 month after VBG, and histological analysis was performed at a macroscopic and microscopic level. RESULTS: There was no peri-operative death, although 2 pigs died in the postoperative period (the first case developed a bowel fistula and sepsis, and the second pig died of unrelated causes). There were 2 additional morbidities (gastric fistula on the linear staple-line away from the Pelvicol band) that led to an early euthanasia of 2 pigs. Post-mortem macroscopic analyses in the remaining 11 pigs did not reveal migration of the device, and there was no tissue reaction on postoperative microscopic analyses. 10 of the pigs had lost weight at 1 month, averaging 3.42 kg. CONCLUSION: Porcine collagen appears to be an effective and safe alternative to the current methods of control of pouch outlet. The flexibility and homogeneity of this prosthesis may be useful to limit the risk of erosion of the gastric wall. Although these properties have been assessed in pelvic operations in humans, this work needs to be studied in a prospective long-term study in humans.
Animals↗
Compression anastomoses revisited.
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Alloys↗
Objective assessment of technical skills in cardiac surgery.
OBJECTIVE: Reduced training time combined with no rigorous assessment for technical skills makes it difficult for trainees to monitor their competence. We have developed an objective bench-top assessment of technical skills at a level commensurate with a junior registrar in cardiac surgery. METHODS: Forty cardiothoracic surgeons were recruited for the study, consisting of 12 junior trainees (year 1-3), 15 senior trainees (year 4-6) and 13 consultants. The assessment consisted of four key tasks on standardised bench-top models: aortic root cannulation, vein-graft to aorta anastomosis, vein-graft to Left Anterior Descending (LAD) anastomosis and femoral triangle dissection. An expert surgeon was present at each station to provide passive assistance and rate performance on a validated global rating scale giving rise to a total possible score of 40. Three expert surgeons repeated the ratings retrospectively, using blinded video recordings. Data analysis employed non-parametric tests. RESULTS: Both live and video scores differentiated significantly between performances of all groups of surgeons for all four stations (P < 0.01) (median live and video score for LAD; Junior 19,17; Senior 29,22; Consultant 36,28). Correlations between live and blinded rating were high (r = 0.67-0.84; P < 0.001) as was inter-rater reliability between the three expert video raters (alpha = 0.81). CONCLUSIONS: The use of bench-top tasks to differentiate between cardiac surgeons of differing technical abilities has been validated for the first time. Furthermore, it is unnecessary to perform post-hoc video rating to obtain objective data. These measures can provide formative feedback for surgeons-in-training and lead to the development of a competency-based technical skills curriculum.
Cardiac Surgical Procedures↗
Synchronized video and motion analysis for the assessment of procedures in the operating theater.
HYPOTHESIS: Objective assessment of surgical skill has recently been shown to be possible through the use of dexterity-based and video analysis systems. The aim of this study was to synchronize these 2 modalities to produce a comprehensive surgical assessment tool. DESIGN: The Imperial College Surgical Assessment Device is a dexterity-based motion analysis device that has been developed in the Department of Surgical Oncology and Technology by the Surgical Computing and Imaging Research Group. Further advances to this system have been made to enable synchronized acquisition of hand kinematics and video from real procedures, and their concurrent analysis. To test the feasibility of the system, 10 laparoscopic cholecystectomies performed by 5 different surgeons on consenting patients were recorded. Analysis focused on the entire procedure and also on specific parts of the operation such as the clipping and cutting of the cystic duct and artery. RESULTS: Dexterity analysis was performed using the objective measures of time, path length, number of movements, velocities, and trajectories. Comparative analysis of a surgeon's dexterity was carried out on the whole procedure and by using the synchronized zoom facility in the software. Kinematic signals revealed rapid changes in velocity caused by alternating between different instruments or occurring after complications such as bleeding. CONCLUSION: This new motion analysis system has been shown to be an effective tool for the comprehensive assessment of operative procedures.
Cholecystectomy, Laparoscopic↗
Assessment of psychomotor skills acquisition during laparoscopic cholecystectomy courses.
BACKGROUND: Standardized short courses in laparoscopic cholecystectomy aim to teach laparoscopic skills to surgical trainees, although end-of-course assessments of performance remain subjective. The current study aims to objectively assess psychomotor skills acquisition of trainees attending laparoscopic cholecystectomy courses. METHODS: Thirty-seven junior surgical trainees had their laparoscopic skills assessed before and after attending 1 of 3 separate 2-day courses (A, B, and C), all with identical format. Assessments were comprised of a standardized simulated laparoscopic task, with performance measured using a valid electromagnetic hand-motion tracking device. RESULTS: Overall, trainees made significant improvements in path length (P=.006), number of movements (P<.001), and time taken (P<.001). Analyzing the 3 courses separately, only trainees attending courses A and C made significant improvements. DISCUSSION: Objective validated methods can be used to assess learning of psychomotor skills on courses. In addition to providing participants with an insight into their skills, these data can be used to demonstrate course efficacy.
Cholecystectomy, Laparoscopic↗
[The development of a surgical education program].
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Curriculum↗
Organising a surgical skills centre.
The aim of this paper is to define a strategy for the development and organisation of a surgical skills centre. The areas of interest can be divided into decisions about who, what and where to teach, the importance of an approach which is competency-based, definition of staff to run the centre, and also the use of the centre for the purposes of assessment, as well as training. The efficient delivery of this service will be augmented by adopting a multi-disciplinary and multi-professional approach, and must also be malleable enough to adopt future developments, such as web-based learning. Simulation is now the preferred mode of practice for commencement of surgical training. Surgical skills centres must be able to supply users with tools in a suitably designed environment, which enables them to move along a curriculum which is delivered in a competency-based manner.
Journal Article↗
Laparoscopic task recognition using Hidden Markov Models.
Surgical skills assessment has been paid increased attention over the last few years. Stochastic models such as Hidden Markov Models have recently been adapted to surgery to discriminate levels of expertise. Based on our previous work combining synchronized video and motion analysis we present preliminary results of a HMM laparoscopic task recognizer which aims to model hand manipulations and to identify and recognize simple surgical tasks.
Clinical Competence↗
Conceptual framework for laparoscopic VR simulators.
Availability of YR laparoscopic simulation for surgical training has increased significantly. Nevertheless, few studies have explored such simulators' requirements and the degree of fidelity necessary to provide effective educational tools. The authors aim to identify which didactic resources available in YR simulation technologies are most important for laparoscopic training.
Computer Graphics↗
Training in laparoscopy--which model to use?
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Animals↗