Motion tracking systems for assessment of surgical skill.
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Clinical Competence↗
Biomedical subjects
A Darzi
Publications and source records attributed to A Darzi.
Objective assessment comparing hand-assisted and conventional laparoscopic surgery.
BACKGROUND: Although several reports have subjectively highlighted the benefits of hand-assisted as compared with conventional laparoscopic surgery, there has been little objective analysis comparing these two techniques. METHODS: For this study, 12 trained laparoscopic surgeons completed standardized knot-tying and dissection tasks in a laparoscopic trainer using both hand-assisted (HandPort) and traditional laparoscopic techniques. Motion analysis with the Imperial College Surgical Assessment Device was used to assess performance, measuring the number of movements made, the path length of hand travel, and the time taken. Mann-Whitney U tests were used to compare hand-assisted (HA) and conventional laparoscopic (L) performance. A p value less than 0.05 was deemed significant. Means and standard deviations are shown in the results. RESULTS: In knot tying, for both the dominant and nondominant hands, hand-assisted rather than conventional laparoscopic techniques resulted in reduced movements (dominant: HA [114 +/- 50] vs L [321 +/- 118, p < 0.001], nondominant: HA [89 +/- 36] vs L [296 +/- 96, p < 0.001]); path length (dominant: HA [1,083 +/- 680 mm] vs L [3,637 +/- 1,852 mm, p < 0.001], nondominant: HA [549 +/- 339 mm] vs L [2,556 +/- 1,042 mm, p < 0.001]); and time taken (HA [162 +/- 50 s] vs L [460 +/- 179 s, p < 0.001]). However, there was no statistical difference for any measured variable with respect to the dissection task. CONCLUSION: Hand-assisted surgery significantly improves the knot-tying ability among trained laparoscopic surgeons. However, there appears to be no improvement in performance for this specific dissection task.
Dissection↗
Early outcomes in the elderly: a meta-analysis of 4921 patients undergoing coronary artery bypass grafting--comparison between off-pump and on-pump techniques.
OBJECTIVE: To assess early outcomes in the elderly population undergoing coronary revascularisation with and without cardiopulmonary bypass (CPB). METHODS: Meta-analysis of all retrospective, non-randomised studies comparing off-pump coronary artery bypass (OPCAB) versus CPB techniques in the elderly (> 70 years) between 1999 and 2005. Age-related early outcomes of interest were death, stroke, atrial fibrillation (AF), renal failure and length of stay in hospital. The random effects model was used. Sensitivity and heterogeneity were analysed. RESULTS: Analysis of 14 non-randomised studies comprising 4921 patients (OPCAB, 1533 (31.1%) and CPB, 3388 (68.9%)) showed a significantly lower incidence of death in the OPCAB group (odds ratio (OR) 0.48, 95% CI 0.28 to 0.84). This effect was greater in OPCAB octogenarians (OR 0.26, 95% CI 0.12 to 0.57). The pattern of incidence of stroke among the OPCAB octogenarians (OR 0.19, 95% CI 0.07 to 0.56) was similar. The incidence of AF was lower in the OPCAB group (OR 0.77, 95% CI 0.61 to 0.97). The incidence of renal failure did not differ. Length of hospital stay was shorter in the OPCAB group, although with significant heterogeneity. CONCLUSIONS: OPCAB may be associated with lower incidence of death, stroke and AF in the elderly, which may result in shorter length of hospital stay. A large randomised trial would confirm whether the elderly would benefit more from OPCAB surgery.
Aged↗
Optimising preoperative diagnosis in phyllodes tumour of the breast.
The role of the pathologist in the preoperative diagnosis of phyllodes tumours of the breast is critical to appropriate surgical planning. However, reliable differentiation of phyllodes tumour from cellular fibroadenoma remains difficult. Preoperative diagnostic accuracy allows correct surgical treatment, avoiding the pitfalls of reoperation because of inadequate excision, or surgical overtreatment. Specific clinical indices may arouse diagnostic suspicion but are unreliable for confirmation, as with current imaging modes. Fine needle aspiration cytology has a high false negative rate. Few studies have evaluated the role of core needle biopsy, but it may prove a useful adjunct. Both diagnostic and prognostic information may in future be gained from application of immunohistochemical and other techniques assessing the expression of proliferative markers including p53, Ki-67, and others.
Adult↗
Virtual reality simulation training can improve inexperienced surgeons' endovascular skills.
PURPOSE: The aim of this study was to evaluate virtual reality (VR) simulation for endovascular training of surgeons inexperienced in this technique. METHODS: Twenty consultant vascular surgeons were divided into those who had performed >50 endovascular procedures (e.g. aortic and carotid stent) as primary operator (n=8), and those having performed <10 procedures (n=12). To test for endovascular skill rather than procedural knowledge, all subjects performed a renal artery balloon angioplasty and stent procedure. The simulator uses real tools with active force feedback, and provides a realistic image of the virtual patient. Surgeons with endovascular skills performed two repetitions and those without completed six repetitions of the same task. The simulator recorded time taken for the procedure, the amount of contrast fluid used and total fluoroscopy time. RESULTS: Initially, surgeons with endovascular skills were significantly faster (median 571.5 vs. 900.0 s, p=0.039) and used less contrast fluid (19.1 vs. 42.9 ml, p=0.047) than inexperienced operators, though differences for fluoroscopy time were not significant (273 vs. 441 s, p=0.305). Over the six sessions, the inexperienced group made significant improvements in performance for time taken (p=0.007) and contrast fluid usage (p=0.021), achieving similar scores at the end of the training program to the experienced group. CONCLUSIONS: Surgeons with minimal endovascular experience can improve their time taken and contrast usage during short-phase training on a VR endovascular task. VR simulation may be useful for the early part of the learning curve for surgeons who wish to expand their endovascular interests.
Angioplasty, Balloon↗
Meta-analysis of colonic reservoirs versus straight coloanal anastomosis after anterior resection.
BACKGROUND AND METHODS: The comparative benefits and drawbacks of straight coloanal anastomosis (CAA), colonic J-pouch and coloplasty anastomosis after anterior resection are uncertain. Studies published between 1986 and 2005 of colonic J-pouch versus transverse coloplasty or straight CAA were analysed. Endpoints included postoperative complications, and functional and physiological outcomes measured within 6 months, 1 year and 2 years or more after the procedure. A random-effect model was used to aggregate the study endpoints and assess heterogeneity. RESULTS: Thirty-five studies containing 2240 patients (1066 straight CAA, 1050 J-pouch and 124 coloplasty) were included. There was no significant difference in postoperative complications between the three groups. There was a significant reduction in the frequency of defaecation per day by 1.88, 1.35 and 0.74 motions at the three time intervals in the J-pouch group compared with the straight CAA group. Faecal urgency was less prevalent in patients with a J-pouch than those with a straight CAA (odds ratio 0.27 at 6 months or less and 0.21 at 1 year). There was no difference in functional outcome between J-pouch and coloplasty anastomosis. CONCLUSIONS: The colonic J-pouch provided functional benefits over straight anastomosis with no increase in postoperative complications. Coloplasty appeared to have similar benefits but further studies are required for validation.
Anal Canal↗
Technical skills examination for general surgical trainees.
BACKGROUND: The technical skills of surgical trainees are difficult to assess and compare objectively. This study involved a structured, multistation, technical skills examination that enables the stratification of surgical trainees. METHODS: Twenty-two surgeons (five basic surgical trainees, eight junior specialist trainees, four senior specialist trainees and five consultants) participated in the study. All undertook a five-station technical skills examination consisting of three synthetic simulations (bowel anastomosis, vascular anastomosis, saphenofemoral dissection) and two virtual reality-based (flexible sigmoidoscopy and laparoscopy) assessment stations. Video-based analyses and in-built computer scoring were used to measure each surgeon's performance. The mean rank was determined for each variable, and the sum of the mean ranks produced a total score. RESULTS: There was a significant improvement in overall performance with increasing seniority (P<0.001). Significant differences were observed between basic surgical trainees and junior specialist trainees (P=0.019), and between junior and senior specialist trainees (P=0.048), but not between senior trainees and consultants. CONCLUSION: This examination successfully differentiated surgical skill, both between surgeons with different grades of experience and within the target study group of specialist trainees. The examination is feasible in terms of the timeframe needed to complete tasks, cost, and efficiency in performing video-based assessments.
Clinical Competence↗
Innovative training for new surgical roles--the place of evaluation.
BACKGROUND: This paper describes the central role of 'external' evaluation, provided by an independent researcher, in developing an innovative curriculum for new professional roles with surgery. Workforce changes affecting the National Health Service provided an opportunity to develop 2 new roles and design training programmes to support them. The perioperative specialist practitioner (PSP) role was designed from scratch, while surgical care practitioner (SCP) training built on existing practice. Training programmes combined formal modules at Imperial College London (approximately 48 days over 10 months) with supervised clinical practice in each participant's base hospital. Programmes balanced factual knowledge, clinical and communication skills, professional issues and personal development and used a range of innovative techniques. EVALUATION METHODS: A qualitative approach based on a utilisation-focused model monitored the development and implementation of 4 pilot PSP and SCP training programmes. A total of 124 individual and 48 group interviews were conducted at intervals over 3 years, sampling course participants, the project team clinical supervisors and administrators. An independent researcher collected, analysed and presented data at key stages, feeding back findings to the project team as the programmes evolved. DISCUSSION: Effective training programmes for new roles can be developed, but the process is time-consuming and requires sensitivity. An independent evaluator offers great benefits, modulating the collaborative partnership between participants and project team. Positive responses (relating to content and teaching methods) from our study enabled us to refine a learner-centred programme. Negative responses often demanded immediate action to address important concerns, and evaluation provided early warning. External evaluation provides a vital perspective in the development of curricula supporting new roles.
Curriculum↗
Assessing procedural skills in context: Exploring the feasibility of an Integrated Procedural Performance Instrument (IPPI).
BACKGROUND: The assessment of clinical procedural skills has traditionally focused on technical elements alone. However, in real practice, clinicians are expected to be able to integrate technical with communication and other professional skills. We describe an integrated procedural performance instrument (IPPI), where clinicians are assessed on 12 clinical procedures in a simulated clinical setting which combines simulated patients (SPs) with inanimate models or items of medical equipment. Candidates are observed remotely by assessors whose data are fed back to the clinician within 24 hours of the assessment. This paper describes the feasibility of IPPI. RESULTS: A full-scale IPPI and 2 pilot studies with trainee and qualified health care professionals has yielded an extensive data set including 585 scenario evaluations from candidates, 60 from clinical assessors and 31 from simulated patients (SPs). Interview and questionnaire data showed that for the majority of candidates IPPI provided a powerful and valuable learning experience. Realism was rated highly. Remote and real-time assessment worked effectively, although for some procedures limited camera resolution affected observation of fine details. DISCUSSION: IPPI offers an innovative approach to assessing clinical procedural skills. Although resource-intensive, it has the potential to provide insight into individual's performance over a spectrum of clinical scenarios and at no risk to the safety of patients. Additional benefits of IPPI include assessment in real time from experts (allowing remote rating by external examiners) as well as provision of feedback from simulated patients.
Clinical Competence↗
Surgery for local recurrence of rectal cancer.
OBJECTIVE: Despite improvement in management of primary rectal cancer, 2.6-32% of patients develop local recurrence. A proportion of these patients can be amenable to salvage surgery. The present article reviews the evidence for and against the surgical management for local recurrence of rectal cancer, the role of adjuvant and intraoperative radiotherapy (IORT), and evaluates short and long-term outcomes. METHOD: A literature search was performed using Medline, Embase, Ovid and Cochrane database for studies between 1980 and 2005 assessing surgical management of local recurrence of rectal cancer and the evidence was critically evaluated. RESULTS: Nearly 50% of rectal cancer recurrences are local and are therefore potentially amenable to curative resection. Preoperative imaging is important for appropriate selection of patients for surgery and preoperative adjuvant therapy is essential. Five-year survival following resection ranges from 18% to 58% with 5-year survival following complete resection of over 35% though morbidity ranges from 21% to 82%. Neoadjuvant radiotherapy is beneficial and IORT may have a contributory role in treatment. Aggressive surgical treatment favourably affects quality of life and is cost effective. Surgery for local recurrence can result in significant long-term survival with acceptable morbidity and improved quality of life in appropriately selected patients. Assessment in a specialist centre familiar with these techniques is essential.
Combined Modality Therapy↗
Virtual reality simulation training can improve technical skills during laparoscopic salpingectomy for ectopic pregnancy.
OBJECTIVES: To assess the first commercially available virtual reality (VR) simulator to incorporate procedural modules for training of inexperienced gynaecological surgeons to perform laparoscopic salpingectomy for ectopic pregnancy. DESIGN: Prospective cohort study. SETTING: Departments of surgery and gynaecology in central London teaching hospitals. SAMPLE: Thirty gynaecological surgeons were recruited to the study, and were divided into novice (<10 laparoscopic procedures), intermediate (20-50) and experienced (>100) groups. METHODS: All subjects were orientated to the VR simulator with a basic skills task, followed by performing ten repetitions of the virtual ectopic pregnancy module, in a distributed manner. MAIN OUTCOME MEASURES: Operative performance was assessed by the time taken to perform surgery, blood loss and total instrument path length. RESULTS: There were significant differences between the groups at the second repetition of the ectopic module for time taken (median 551.1 versus 401.2 versus 249.2 seconds, P = 0.001), total blood loss (median 304.2 versus 187.4 versus 123.3 ml, P = 0.031) and total instrument path length (median 17.8 versus 8.3 versus 6.8 m, P = 0.023). The learning curves of the experienced operators plateaued at the second session, although greater numbers of sessions were necessary for intermediate (seven) and novice (nine) surgeons to achieve similar levels of skill. CONCLUSIONS: Gynaecological surgeons with minimal laparoscopic experience can improve their skills during short-phase training on a VR procedural module. In contrast, experienced operators showed nonsignificant improvements. Thus, VR simulation may be useful for the early part of the learning curve for surgeons who wish to learn to perform laparoscopic salpingectomy for ectopic pregnancy.
Clinical Competence↗
Does clopidogrel affect outcome after coronary artery bypass grafting? A meta-analysis.
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Blood Loss, Surgical↗
The perioperative specialist practitioner: developing and evaluating a new surgical role.
INTRODUCTION: This paper describes the design, implementation and evaluation of a new professional role in surgery. The role of the perioperative specialist practitioner (PSP), conceived as a response to the Working Time Directive, provides integrated preoperative and postoperative care to patients undergoing surgery in hospital. METHODS: A 1-year training programme was designed, dealing with a wide range of knowledge, skills and attitudes. Effective communication was a key component. Nine intensive 5-day modules at Imperial College London (London, UK) alternated with supervised experience of the surgical team at each participant's home trust. Detailed evaluation of the role and the training programme was provided by an independent research team, using an interview-based qualitative approach. Observational data were provided by the project team. Data were analysed using standard qualitative methods. RESULTS: 27 PSPs across 12 National Health Service trusts took part in two PSP training programmes. A total of 124 interviews (94 individual and 30 group) were carried out with PSPs and their colleagues. Overall, the role was seen as successful and positive, with great potential for dealing with reductions in junior medical cover. Each site encountered different opportunities and problems. Lack of mentorship was a key issue, and the role provoked considerable opposition in trusts. The training programme was viewed as highly successful. DISCUSSION: PSPs can provide high levels of expertise, but within clear limits. Our training programme has been effective and is perceived to be of high quality. However, introducing a new role requires time and sensitivity if opposition is to be minimised.
Adult↗
Training in the operating theatre: is it safe?
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Clinical Competence↗
Simulating tele-manipulator controlled tool-tissue interactions using a nonlinear FEM deformable model.
Enhanced visualization of an operating scene presented by a robotically assisted tele-manipulator system such as the da Vinci(TM) can be provided through the use of augmented reality facilities. Generating overlays from 3D models and the intra-operative video allows the surgeon to acquire greater information about the surgical scene. Tool-tissue interactions must be tracked to ensure the overlays are updated regularly and accurately. The work presented here describes how these interactions may be modelled by integrating a nonlinear finite element model with the 3D reconstruction and using the tool kinematic data as input to the deformation.
Connective Tissue↗
Variant Creutzfeldt-Jakob disease: a cause for concern. Review of the evidence for risk of transmission through abdominal lymphoreticular tissue surgery.
BACKGROUND: Concern has long existed regarding the possible iatrogenic spread of variant Creutzfeldt-Jakob disease (v-CJD) through surgery. This had been fueled by recent reports of bovine spongiform encephalopathy in U.S. cattle and the first probable case of blood transmission of v-CJD in the UK. METHODS: Systematic review of experimental and nonexperimental studies. Studies identified from searches of Medline, Embase, Cochrane Library, Science Citation Index medical databases, searching bibliographies of retrieved papers, and personal communication with international experts in the field. RESULTS: Six articles satisfied our search criteria. Evidence stems from case reports, case series, and cross-sectional studies. There are no published cases of surgically transmitted v-CJD. CONCLUSION: We found evidence of v-CJD prion agents in the spleen, appendix, rectum, and adrenal glands of affected patients and evidence of v-CJD prion in the appendix of patients in the preclinical stage of the disease. The risk of transmission of v-CJD prion during abdominal surgery is currently unquantifiable.
Abdomen↗
Simulation based training.
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Clinical Competence↗
Selection of individuals for training in surgery.
Surgical training in the United Kingdom and Europe is in transition given the pressure to decrease the number of workweek hours and the numbers of years in training. To achieve this shortened training in the United Kingdom, the primary component will be the foundational education, which will last for 2 years, with the second year perhaps counting toward specialist training. It would be a potential advantage for achieving rapid surgical training if we could preselect those students with the necessary attributes of a surgeon. During the foundation period there is exists the question of assessment, so this might be a natural point at which to preselect these students. This article considers psychometric assessment as a methodology of preselecting surgeons and considers objective assessment as a possibility during the foundational education period.
Career Choice↗