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S Bann

Publications and source records attributed to S Bann.

16 recordsLinked to original sources
PubMed2006

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↗
PubMed2006

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↗
PubMed2004

The benefits of stereoscopic vision in robotic-assisted performance on bench models.

BACKGROUND: Previous studies have failed to establish clear advantages for the use of stereoscopic visualization systems in minimal-access surgery. The aim of this study was to objectively assess whether stereoscopic visualization improves performance on bench models using the da Vinci robotic system. METHODS: Eleven surgeons carried out a series of four tasks. Positional data streamed from the da Vinci system was analyzed by means of a previously validated custom-designed software-package. An independent blinded observer scored errors. Statistical analysis included the Wilcoxon signed rank test. A p < 0.05 was deemed significant. RESULTS: We found significant improvements in all tasks and for all parameters (p < 0.05). In addition, a significantly lower number of errors was scored using the stereoscopic mode as compared to the standard two-dimensional image (p < 0.001). CONCLUSION: Robotic-assisted performance on bench models is more efficient and accurate using stereoscopic visualization.

Data Display↗
PubMed2004

Laparoscopic virtual reality and box trainers: is one superior to the other?

BACKGROUND: Virtual reality (VR) simulators now have the potential to replace traditional methods of laparoscopic training. The aim of this study was to compare the VR simulator with the classical box trainer and determine whether one has advantages over the other. METHODS: Twenty four novices were tested to determine their baseline laparoscopic skills and then randomized into the following three group: LapSim, box trainer, and no training (control). After 3 weekly training sessions lasting 30-min each, all subjects were reassessed. Assessment included motion analysis and error scores. Nonparametric tests were applied, and p < 0.05 was deemed significant. RESULTS: Both trained groups made significant improvements in all parameters measured ( p < 0.05). Compared to the controls, the box trainer group performed significantly better on most of the parameters, whereas the LapSim group performed significantly better on some parameters. There were no significant differences between the LapSim and box trainer groups. CONCLUSIONS: LapSim is effective in teaching skills that are transferable to a real laparoscopic task. However, there appear to be no substantial advantages of one system over the other.

Adult↗
PubMed2003

Validity and reliability of a virtual reality upper gastrointestinal simulator and cross validation using structured assessment of individual performance with video playback.

BACKGROUND: This study aims to evaluate the ability of an upper gastrointestinal virtual reality simulator to assess skills in endoscopy, and to validate its metrics using a video-endoscopic (VES) technique. METHODS: The 32 participants in this study were requested to undertake two cases on the simulator (Simbionix, Israel). Each module was repeated twice. The simulator's metrics of performance were used for analysis. two blinded observers rated performance watching the simulator's playback feature. RESULTS: There were 11 novices (group 1), 11 trainees with intermediate experience (10-50 procedures, group 2), and 10 experienced endoscopists (>200 procedures, group 3). There was a significant difference in the total time required to perform the procedure (p < 0.001), percentage of mucosa visualized (p < 0.001), percentage of pathologies visualized (p < 0.001), and number of inappropriate retroflexions (p = 0.015) across the three groups. The reliability of assessment on the simulator was greater than 0.80 for all parameters. The VES assessment also was able to discriminate performance across the groups (p < 0.001). There was a significant correlation between the VES score and the percentage of mucosa visualized (rho = 0.60; p < 0.001). CONCLUSIONS: The upper gastrointestinal simulator may be a useful tool for determining whether a trainee has achieved a desired level of competence in endoscopy. The next step will be to validate the VES score in real procedures.

Endoscopy, Gastrointestinal↗
PubMed2003

The effect of stress-inducing conditions on the performance of a laparoscopic task.

BACKGROUND: The availability of objective means for assessment of surgical skills has made it possible to evaluate the effect of adverse environmental conditions on surgical performance. METHODS: Participants performed a laparoscopic transfer task under five conditions: a simple verbal mathematical task (M), operating theatre background noise at 80 to 85 dB (N), performance as quickly as possible (T), all three stressors combined (A), and quiet conditions (Q). The effect of these conditions on performance was evaluated by using a motion analysis system and an error score. RESULTS: The study included 13 right-handed surgeons with varying levels of laparoscopic experience. There was a significant increase in the path length per movement of the right hand (p = 0.001) under T and a significant increase in the path length per movement of the left hand under M (p = 0.002), T (p = 0.01), and A (p = 0.02). A significantly higher number of errors occurred under all four stress-inducing conditions. The effect was more pronounced when all the stressors were applied in combination ( p = 0.001) followed by performance under M (p = 0.005), then T (p = 0.01) and N (p = 0.03). CONCLUSIONS: All three stressors led to impaired dexterity and an increase in the incidence of errors.

Adult↗
PubMed2003

Objective assessment of technical skills of surgical trainees in Hong Kong.

BACKGROUND: The need for assessment of technical skills is well recognized and objective methods of assessment are currently under investigation in the UK. The applicability of these assessment tools to trainees with a different training background in another country was examined. METHODS: Six bench-top models for basic surgical trainees (BSTs) and eight for higher surgical trainees (HSTs) (five in common) were assessed for construct validity in 70 subjects. Objective assessment methods included motion analysis using the Imperial College Surgical Assessment Device, Objective Structured Assessment of Technical Skills and Minimally Invasive Surgical Trainer in Virtual Reality. RESULTS: All models shared between BSTs and HSTs exhibited construct validity (range P = 0.050 to P < 0.001). Of the three modules for HSTs alone, only one gave significant results (small bowel anastomosis; P = 0.005). Reasons for this were sought. CONCLUSION: The methods of objective technical skills assessment of trainees in the UK are applicable to those in Hong Kong. Their use should be promoted and the tracking of skills development encouraged.

Adult↗
PubMed2003

Learning the skills of flexible sigmoidoscopy - the wider perspective.

BACKGROUND: Nurse-led gastrointestinal endoscopy is a priority clinical area in the UK. Endoscopic procedures are challenging to learn, requiring a combination of technical competence (manipulating a flexible endoscope and interpreting the findings) and interpersonal skills (engaging effectively with a conscious patient who is frequently apprehensive). This paper explores the potential of an innovative, scenario-based approach which links a simulated patient with a computer-driven virtual reality (VR) training device for flexible sigmoidoscopy. Within this safe yet realistic quasi-clinical environment, learners carry out the procedure while interacting with the 'patient'. Communication skills are assessed by simulated patients, while quantitative performance data relating to the procedure is generated automatically by the VR simulator. METHODS: This pilot study took place within a nurse practitioner endoscopy course. A mixed methodology combined qualitative and quantitative data (observation and interview studies, communication rating scales and a range of computer-generated output measures from the VR simulator) in a multifaceted evaluation. RESULTS: Seven nurses took part in the study. Participants found the scenarios to be a convincing and powerful learning experience. All experienced high levels of anxiety. Simulated patients identified strengths in participants' communication skills, together with areas for development. Simulator-based practice led to an improvement in objective performance measures. DISCUSSION: Scenario-based training provides a powerful learning experience, allowing participants to build their technical expertise and apply it within a holistic clinical context without the risk of causing harm. We used this pilot study as a springboard for discussions over wider implications of procedure-based skills training, locating it within the literature on expertise and situated learning.

Clinical Competence↗
PubMed2002

The Surgical Risk Scale as an improved tool for risk-adjusted analysis in comparative surgical audit.

BACKGROUND: Comparative surgical audit is becoming increasingly important although it is fraught with difficulties due to risk-adjusted analysis. Methods have been proposed to solve this problem and allow meaningful comparison of patient outcome. None has been described without faults, making such comparison flawed or overtly complicated. An alternative risk scoring system incorporating the Confidential Enquiry into Perioperative Deaths (CEPOD) grade, the American Society of Anesthesiologists (ASA) grade and the British United Provident Association (BUPA) operative grade was formulated and assessed. METHODS: This was a prospective audit of 4308 patients admitted under the care of three surgeons between May 1997 and October 1999, creating an initial data set of 3144 procedures with 134 deaths. Each procedure was allocated a score on the basis of the CEPOD, BUPA and ASA grade. The Surgical Risk Scale (SRS) was devised by adding together the values of the three variables, which generated a scale ranging from 3 to 14. Multivariate logistic regression analysis involving the three variables and univariate analysis of the SRS score were undertaken. Receiver-operator characteristic and calibration curves were formulated. This process was validated on another data set (2780 patients) derived from all admissions to the same surgeons between November 1999 and December 2000. RESULTS: Univariate logistic analysis of the SRS score revealed it to be significantly predictive of death (beta = 0.84, P < 0.001); it did not overpredict mortality for low-risk procedures. CONCLUSION: The SRS is easy to use, formulate and interpret, and provides an accurate prediction of death in general surgical patients across the entire risk spectrum.

England↗
PubMed1992

Extensive malignant schwannoma of the mandibular nerve. Case report.

An extensive malignant schwannoma of the mandibular nerve in an 8-year-old boy is presented. The clinical presentation, light microscopic findings, and radiographic features are described. The patient was successfully treated with surgery in combination with chemotherapy. He is still well, without evidence of metastasis or local recurrence, 5 years postoperatively.

Child↗
PubMed1985

[DNA-RNA cytofluorometric analysis of a case of osteosarcoma in relation to histological characteristics].

We applied DNA-RNA cytofluorometry with AO stain to cell kinetic analysis of osteosarcoma in a 12-year-old girl in relation to its histological characteristics. Histological findings obtained for 9 macroscopically different lesions were grouped into 4 main structural characteristics, but their cytofluorometric results were classified into 2 main patterns of DNA-RNA distribution. One showed remarkable polyploidization with many DNA synthetic cells in the invasive lesions, which were composed of pleomorphic cells forming osteoid or occasionally cartilaginous matrix. The other showed marked accumulation of tetraploid cells almost without DNA synthetic cells, being composed of relatively uniform fibroblastic or stellate-like cells in the cartilaginous matrix. These results indicated a close relationship between cell proliferative activity and the tissue environment.

Bone Neoplasms↗
PubMed1984

[DNA cytofluorometry of soft tissue tumors].

We carried out DNA cytofluorometry with propidium iodide stain on the 17 cases of soft tissue tumors including giant cell tumor of the tendon sheath, pigmented villonodular synovitis, 2 hemangiomas, 3 lipomas, 5 schwannomas, 3 neurofibromas, liposarcoma and synovial sarcoma. The benign tumors were characterized by regular polyploidization with very few S-phase cells, indicating slow tumor growth. Most of the malignant soft tissue tumors were associated with remarkable polyploidization with an increase in S-phase cells. However, some malignant tumors did not show polyploidization. We concluded, therefore, that an increase in S-phase cells is an important, cytofluorometric criterion for malignancy of soft tissue tumors.

Adult↗
PubMedDate not supplied

Evaluation of virtual reality bronchoscopy as a learning and assessment tool.

BACKGROUND: Conventional training in bronchoscopy involves a trainee performing on a real patient under supervision. This method of training is not only expensive, but there is also potential for increased patient discomfort. Simulators permit the acquisition of necessary technical skills required for the procedure. Virtual reality (VR) has been an integral part of training in aviation, and the application of this technology in medical training needs to be evaluated. OBJECTIVE: This study was conducted to evaluate the efficacy of a VR bronchoscopy simulator as a learning and assessment tool. METHODS: The bronchoscopic simulator (HT Medical Systems, Maryland, USA) is a VR computer programme. The simulator has the ability to assess competence by a set of parameters, which formed the data for the study. Nine novices without previous bronchoscopic experience formed the study group (group 1). Nine experienced bronchoscopists having performed between 200 and 1000 bronchoscopies formed the other group (group 2). We assessed the efficacy of the system as a learning tool by studying whether there was a significant difference between the first and subsequent sessions of the subjects from group 1 and by comparing the performance of the two groups. Statistical analysis was done using the Mann-Whitney U test and the Wilcoxon signed ranks test. RESULTS: There was a significant difference in performance between the first attempt of group 1 and the performance of the experts in terms of percentage of segments visualised and number of wall collisions and the economy of performance. Among the subjects from group 1, there was a significant improvement in percentage of segments visualised by the third attempt (p = 0.04), in the economy of performance by the sixth attempt (0.008) and in the number of wall collisions by the sixth attempt (0.024). When each attempt of the novices was compared with the performance of group 2, the significance in the difference of the percentage of segments studied (p = 0.09) and the economy of performance disappeared by the third attempt (0.06), while the difference in the number of wall collisions disappeared by the fifth attempt (p = 0.06). CONCLUSIONS: This study has been able to establish the face, construct and content validity of the simulator and the potential for it to be an effective training tool.

Bronchoscopy↗