Development of Surgical Error Reduction System (SERS) for Laparoscopic Appendectomy by using Observational Human Reliability Analysis (OCHRA) model and to analyse its impact on patient outcomes.

This project is to develop a surgical error reduction system (SERS) for laparoscopic appendectomy by using observational Human Reliability Analysis (OCHRA) model and to analyse it impact on patient's outcome.

Real-Time 3D Tracking of Laparoscopy Training Instruments for Assessment and Feedback.

Assessment of minimally invasive surgical skills is a non-trivial task, usually requiring the presence and time of expert observers, including subjectivity and requiring special and expensive equipment and software. Although there are virtual simulators that provide self-assessment features, they are limited as the trainee loses the immediate feedback from realistic physical interaction. The physical training boxes, on the other hand, preserve the immediate physical feedback, but lack the automated self-assessment facilities. This study develops an algorithm for real-time tracking of laparoscopy instruments in the video cues of a standard physical laparoscopy training box with a single fisheye camera. The developed visual tracking algorithm recovers the 3D positions of the laparoscopic instrument tips, to which simple colored tapes (markers) are attached. With such system, the extracted instrument trajectories can be digitally processed, and automated self-assessment feedback can be provided. In this way, both the physical interaction feedback would be preserved and the need for the observance of an expert would be overcome. Real-time instrument tracking with a suitable assessment criterion would constitute a significant step towards provision of real-time (immediate) feedback to correct trainee actions and show them how the action should be performed. This study is a step towards achieving this with a low cost, automated, and widely applicable laparoscopy training and assessment system using a standard physical training box equipped with a fisheye camera.

Evidence to support the early introduction of laparoscopic suturing skills into the surgical training curriculum.

BACKGROUND: The objectives of this study were to investigate the relationship between the acquisition of laparoscopic suturing skills and other operative laparoscopic skills and to provide evidence to determine ideal time and duration to introduce laparoscopic suturing training. METHODS: The first part of the study explored the relationship between the acquisition of laparoscopic suturing skills and proficiency of other operative laparoscopic skills. The second part of the study consisted of an opinion survey from senior and junior trainees on aspects of training in laparoscopic suturing. RESULTS: One hundred twenty-eight surgical trainees participated in this study. The total scores of task performance of 57 senior surgical trainees in laparoscopic suturing skills consisting of needle manipulation and intracoporeal knot tying were improved significantly after the training course (46.9 ± 5.3 vs 29.5 ± 9.4, P < .001), the improvement rate was 59%. No statistically significant correlations were observed between intracorporeal laparoscopic suturing skills and proficiency in the basic laparoscopic manipulative skills assessed before (r = 0.193; P = 0.149) and after (r = 0.024; P = 0.857) the training course. 91% of senior trainees and 94% junior trainees expressed that intracorporeal suturing should be introduced at an early stage of the training curriculum. CONCLUSIONS: There was no statistically significant correlation between the performance on basic operative laparoscopic skills (non-suturing skills) and laparoscopic suturing skills observed in this study. The acquisition of basic laparoscopic skills is not a prerequisite for training in intracorporeal suturing and it may be beneficial for the surgical trainees to learn this skill early in the surgical training curriculum. Surgical trainees want to learn and practice laparoscopic suturing earlier than later in their training.

Objective assessment of surgical operative performance by observational clinical human reliability analysis (OCHRA): a systematic review.

BACKGROUND: Both morbidity and mortality data (MMD) and learning curves (LCs) do not provide information on the nature of intraoperative errors and their mechanisms when these adversely impact on patient outcome. OCHRA was developed specifically to address the unmet surgical need for an objective assessment technique of the quality of technical execution of operations at individual operator level. The aim of this systematic review was to review of OCHRA as a method of objective assessment of surgical operative performance. METHODS: Systematic review based on searching 4 databases for articles published from January 1998 to January 2019. The review complies with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and includes original publications on surgical task performance based on technical errors during operations across several surgical specialties. RESULTS: Only 26 published studies met the search criteria, indicating that the uptake of OCHRA during the study period has been low. In 31% of reported studies, the operations were performed by fully qualified consultant/attending surgeons and by surgical trainees in 69% in approved training programs. OCHRA identified 7869 consequential errors (CE) during the conduct of 719 clinical operations (mean = 11 CEs). It also identified 'hazard zones' of operations and proficiency-gain curves (P-GCs) that confirm attainment of persistent competent execution of specific operations by individual trainee surgeons. P-GCs are both surgeon and operation specific. CONCLUSIONS: Increased OCHRA use has the potential to improve patient outcome after surgery, but this is a contingent progress towards automatic assessment of unedited videos of operations. The low uptake of OCHRA is attributed to its labor-intensive nature involving human factors (cognitive engineering) expertise. Aside from faster and more objective peer-based assessment, this development should accelerate increased clinical uptake and use of the technique in both routine surgical practice and surgical training.

A Comparative Study of Generic Visual Components of Two-Dimensional Versus Three-Dimensional Laparoscopic Images.

AIMS: There is a strong evidence to suggest that 3D imaging improves the laparoscopic task performance when compared against 2D. However, to date, no study has explained why that might be. We identified six generic visual components during laparoscopic imaging and aimed to study each component in both 2D and 3D environments for comparison. METHODS: Twenty-four consented laparoscopic novices performed specific isolated tasks in a laparoscopic Endo Trainer in 2D and 3D separately. The six endpoints were the accuracy in detecting changes in the laparoscopic images in the following components: distance, area, angle, curvature, volume and spatial coordinates. All the components except the spatial coordinates were assessed by creation, measurement and comparison. Each component was analysed between 2D and 3D groups and within each group at different values. Tests of spatial coordinates were video-recorded and analysed for error number and error types by human reliability analysis technique. Errors types included past-pointing, not reaching the object and touching the wrong object. The results were statistically analysed with independent T test. RESULTS: There was no statistically significant difference between 2D and 3D accuracy in the angle, area, distance and curvature. 3D performed more accurately in comparing volumes (p = 0.05). In spatial coordinates, there were a statistically significant higher number of errors in 2D as compared to 3D (p < 0.001). Past-pointing and touching the wrong objects were significantly higher in 2D (p < 0.05). CONCLUSION: Between all the visual components, detecting change in volume and the spatial coordinates showed significant improvement in 3D environment when compared to 2D.

A training tool to assess laparoscopic image navigation task performance in novice camera assistants.

BACKGROUND: A number of tools for assessing task performance of the laparoscopic camera assistant have been described, but few focus on the acquisition and assessment of the attainment of proficiency in novice laparoscopic camera assistants. Our aim was to develop a simulated objective assessment tool for a novice camera assistant. MATERIALS AND METHODS: A 10-cycle image navigation task tool was developed. This involved a series of 360° clockwise and anticlockwise rotation maneuvers of a 30° laparoscope along its shaft, focusing on a predefined geometric target on a 45° fixed slope in a laparoscopic box trainer. The tasks were to simultaneously maintain neutral horizon, optimum distance, and centering. Task accuracy and time to completion were assessed objectively at 3-s intervals on an unedited video recording. RESULTS: Twenty-nine novice medical students were assessed. Novices improved mean total error and task completion time (first versus fifth cycle, mean errors 15.4 versus 8.4, P = 0.048; mean task time 158.1 versus 92.9 s, P = 0.04). This improvement continued until the task cycle was completed (sixth versus 10th cycles, 7.9 versus 6.2, P = 0.01; 91.9 versus 76.6 s, P < 0.0001). There was a significant decrease in centering errors (5.2 versus 2.4, P = 0.001) and horizon (4.8 versus 2.3, P = 0.004), when comparing the first versus fifth task cycle. It took six cycles for optimum distance to achieve significance (5.4 versus 3.3, P = 0.023). CONCLUSIONS: Using our assessment tool, novices achieved an objective proficiency-gain curve for laparoscopic camera navigation tasks. There was improvement in errors related to maintaining horizon, optimum distance, and centering. Mean task completion time also decreased. This tool could be used as an additional mean of assessment and training in novice surgical trainees.

Ureterorenoscopy training on cadavers embalmed by Thiel's method: simulation or a further step towards reality? Initial report.

INTRODUCTION: The technique of ureterorenoscopy has a significant learning curve. Cadavers embalmed by the Thiel method have been successfully used for simulation training in a number of surgical specialties. Here we present our experience of the first use of Thiel cadavers in a formal ureteroscopy training course. MATERIAL AND METHODS: The inaugural 'Masterclass in Flexible Ureterorenoscopy' was run with participants performing ureterorenoscopy on three Thiel cadavers under expert supervision. A qualitative questionnaire was delivered to the participants and faculty. Assessed domains were tissue characteristics of the cadaveric urinary tract, anatomical features and procedural aspects. A five-point Likert score was used to assess responses. Data regarding participant experience in endourology were also collected. RESULTS: 8 questionnaires were collected. All participants completed cadaveric ureterorenoscopy. Three-quarters reported the overall quality of tissue in the cadaveric bladder, ureters and pelvicalyceal system as high or excellent. Half reported the cadaveric bladder as being softer than in a live patient, whilst five out of eight thought that the cadaveric ureter was softer and more prone to trauma. Seven out of eight were satisfied with the overall quality of the cadaveric model. The quality of vision and irrigation in the upper urinary tracts was reported as high. CONCLUSIONS: Thiel cadavers have been shown to have excellent tissue characteristics, as well as being durable and reusable. We have described the first use of Thiel cadavers in a designated ureterorenoscopy course, with high levels of delegate satisfaction. Further work is required to develop the role of Thiel cadavers as part of an integrated, modular urology training.

Development and Validation of a Novel and Cost-Effective Animal Tissue Model for Training Transurethral Resection of the Prostate.

OBJECTIVES: To develop and validate a new and cost-effective animal tissue training model for practicing resection skills of transurethral resection of the prostate (TURP). METHODS AND MATERIALS: A porcine kidney was prepared and restructured to simulate the relevant anatomy of the human prostate. The restructured prostate was connected to an artificial urethra and bladder. Face, content, and construct validity of the model was carried out using a 5-point Likert scale questionnaire, and comparison in task performance between participants and experts was made using observational clinical human reliability analysis. RESULTS: A total of 24 participants and 11 experts who practiced TURP skills on this model from October 2014 to December 2015 were recruited. The mean score on specific feature of the anatomy and color, sensation of texture and feeling of resection, conductibility of current, and efficacy and safety of the model were 4.34 ± 0.37, 4.51 ± 0.63, 4.13 ± 0.53, and 4.35 ± 0.71, respectively, by participants whereas they were 4.22 ± 0.23, 4.30 ± 0.48, 4.11 ± 0.62, and 4.56 ± 0.77, respectively, by the experts on a scale of 1 (unrealistic) to 5 (very realistic). Participants committed more technical errors than the experts (11 vs 7, p < 0.001), produced more movements of the instruments (51 vs 33, p < 0.001), and required longer operating time (11.4 vs 6.2min, p < 0.001). CONCLUSIONS: A newly developed restructured animal tissue model for training TURP was reported. Validation study on the model demonstrates that this is a very realistic and effective model for skills training of TURP. Trainees committed more technical errors, more unproductive movements, and required longer operating time.

The effect of a performance-based intra-procedural checklist on a simulated emergency laparoscopic task in novice surgeons.

Surgical checklists are in use as means to reduce errors. Checklists are infrequently applied during emergency situations in surgery. We aimed to study the effect of a simple self-administered performance-based checklist on the laparoscopic task when applied during an emergency-simulated scenario. The aviation checklist for unexpected situations is commonly used for simulated training of pilots to handle emergency during flights. This checklist was adopted for use as a standardised-performance-based checklist during emergency surgical tasks. Thirty consented laparoscopic novices were exposed unexpectedly to a bleeding vessel in a laparoscopic virtual reality simulator as an emergency scenario. The task consisted of using laparoscopic clips to achieve haemostasis. Subjects were randomly allocated into two equal groups; those using the checklist that was applied once every 20 s (checklist group) and those without (control group). The checklist group performed significantly better in 5 out of 7 technical factors when compared to the control group: right instrument path length (m), median (IQR) 1.44 [1.22] versus 2.06 [1.70] (p = 0.029), right instrument angular path (degree) 312.10 (269.44 versus 541.80 [455.16] (p = 0.014), left instrument path length (m) 1.20 [0.60] versus 2.08 [2.02] (p = 0.004), and left instrument angular path (degree) 277.62 [132.11] versus 385.88 [428.42] (p = 0.017). The checklist group committed significantly fewer number of errors in the application of haemostatic clips, 3 versus 28 (p = 0.006). Although statistically not significant, total blood loss (lit) decreased in the checklist group from 0.83 [1.23] to 0.78 [0.28] (p = 0.724) and total time (sec) from 186.51 [145.69] to 125.14 [101.46] (p = 0.165). The performance-based intra-procedural checklist significantly enhanced the surgical task performance of novices in an emergency-simulated scenario.

The effect of a simple intraprocedural checklist on the task performance of laparoscopic novices.

BACKGROUND: Surgical checklists are used for error reduction. Checklists are infrequently applied during procedures and have been limited to lists of procedural steps as aid memoires. We aimed to study the effect of a self-administered checklist on the laparoscopic task performance of novices during a standardized task. METHODS: Twenty novices were randomized into 2 equal groups, those receiving paper feedback (control group) and those receiving paper feedback and the checklist (checklist group). Subjects performed laparoscopic double knots, repeated over 5 separate stages. Human reliability assessment technique was used for error analysis. RESULTS: 2,341 errors were detected during the 5 stages. During the first stage, the errors were not significantly different between the 2 groups. The checklist group committed significantly fewer errors as compared with the control group during all the later 4 stages (P < .01). CONCLUSIONS: The simple intraprocedural checklist significantly improved the laparoscopic task performance and the learning curve of laparoscopic novices.

Videotaping of surgical procedures and outcomes following extraperitoneal laparoscopic radical prostatectomy for clinically localized prostate cancer.

BACKGROUND: Video-recording of emerging minimally invasive surgical procedures is likely to become an integral component of patient record-keeping in the future for prostate cancer treatment. No prior work has shown the impact of videotaping of laparoscopic prostatectomy on patient outcomes. Our aim was to determine correlation between independent peer review of videotaping quality scores of extraperitoneal laparoscopic prostatectomy (ELRP) with complications, re-admissions, functional, and early oncological outcomes. STUDY DESIGN, SETTING, AND PARTICIPANTS: We conducted a single-institution prospective cohort study comparing videotaping quality scores with the outcomes of ELRP in men with localized prostate cancer. Videotaping of surgical procedures were scored by two experienced laparoscopic surgeons using a validated scoring method. Validated record-linkage methodology and self-reported questionnaires were used to assess surgical complications, re-admissions, functional, and oncological outcomes based on a common identifier called as community health index (CHI) number. Pearson correlation coefficients were calculated between the different covariates with statistical significance considered at P < 0.05. Multivariate analyses assessed oncological outcomes (positive surgical margins/biochemical recurrence), post-operative complications, and re-admission into hospital following initial hospital discharge with quality of surgical procedure. RESULTS: 200 men were recruited into the study. 51 (25.5%) participants had post-operative complications. Record-linkage methodology identified 18 (9%) participants had re-admissions within 90 days of the procedure. 13 (6.5%) of these men required percutaneous drainage with hospital stay following re-admissions ranged between 3 and 12 days. 10 (5.0%) participants had intra/peri-operative complications. 23 (11.5%) men reported to primary care physicians for various indications. Higher quality surgical technique videotaped scores (assessed by independent peer review) had a significant correlation with early continence recovery at 3 months post-procedure, (P = 0.013), but lost statistical significance with overall continence at 1 year. No statistical correlation was observed between videotaped scores and oncological outcomes (positive surgical margins/biochemical recurrence), post-operative complications, and readmission into hospital. CONCLUSIONS: Quality of surgical procedure assessed by independent third party videotaping score predicted early resumption of continence following extraperitoenal laparoscopic radical prostatectomy, however, it did not predict complications, oncological or functional outcome as assessed using patient reported outcomes at 12 months. J. Surg. Oncol. 2016;114:1016-1023. © 2016 Wiley Periodicals, Inc.

A hydraulically driven colonoscope.

BACKGROUND: Conventional colonoscopy requires a high degree of operator skill and is often painful for the patient. We present a preliminary feasibility study of an alternative approach where a self-propelled colonoscope is hydraulically driven through the colon. METHODS: A hydraulic colonoscope which could be controlled manually or automatically was developed and assessed in a test bed modelled on the anatomy of the human colon. A conventional colonoscope was used by an experienced colonoscopist in the same test bed for comparison. Pressures and forces on the colon were measured during the test. RESULTS: The hydraulic colonoscope was able to successfully advance through the test bed in a comparable time to the conventional colonoscope. The hydraulic colonoscope reduces measured loads on artificial mesenteries, but increases intraluminal pressure compared to the colonoscope. Both manual and automatically controlled modes were able to successfully advance the hydraulic colonoscope through the colon. However, the automatic controller mode required lower pressures than manual control, but took longer to reach the caecum. CONCLUSIONS: The hydraulic colonoscope appears to be a viable device for further development as forces and pressures observed during use are comparable to those used in current clinical practice.

Liver retraction system by C3-muco-adhesive polymer films for laparoscopic surgery.

BACKGROUND: Conventional laparoscopic instruments used for retraction may cause trauma at the retraction site. Alternative retraction/lifting especially of heavy solid organs such as the liver may be obtained by other means. The present study was designed to explore the use of C3-muco-adhesive polymers (C3-MAPs), which exhibit strong binding to the liver shortly after application to the organ and which retain strong adhesion for sufficient time, to enable sustained retraction during laparoscopic operations. METHODS AND MATERIALS: C3-muco-adhesive polymers were produced specifically for the study. In an ex vivo experimental set-up, discs of C3-MAPs were placed on the surface of porcine livers for adhesion and retraction studies involving objective measurements by tensiometry. RESULTS: Experiments were carried out on 14 porcine livers. The force required to detach the C3-MAPs from the liver exceeded 2.0 N 30 s after application. The adhesion force by C3-MAPs files was sufficient to enable sustained retraction force necessary for exposure of the gall bladder, which was achieved by a mean retraction force of 4.85 N (SD = 0.63). This was sustained for a mean of 130 min (range 17.0-240.0). In the adhesion studies, the forces at 30 s required to detach the polymer discs from the liver exceeded 20 N (upper limit of the load cells of the Instron). The duration of the adhesion enabled sustained optimal gall bladder exposure for periods ranging from 17 to 240 min, with a mean of 130 ± 91 min. CONCLUSIONS: The results of the present study demonstrate that the adhesion and retraction properties of the engineered C3-MAP films are sufficient to enable complete exposure of the gall bladder for a period exceeding 1 h, confirming their potential for atraumatic retraction in laparoscopic and other minimal-access surgical approaches.

Preliminary validation of Thiel embalmed cadavers for laparoscopic radical nephrectomy.

PURPOSE: This study evaluated face, content, construct validity, and reliability of Thiel embalmed cadavers (TEC) as a training tool for transperitoneal laparoscopic nephrectomy (TLN). MATERIALS AND METHODS: The study participants were prospectively recruited through an advanced laparoscopic renal resection teaching skill course. The participants were grouped into: nonexperts (performed fewer than 50 TLNs) and experts (performed more than 50 TLNs). All the participants performed TLN on TEC, which was video recorded. All participants rated their overall experience of performing TLN on TEC with emphasis on realism (face validity). The participants were asked to rate the appropriateness of TEC for training in TLN (content training). Two experienced laparoscopic surgeons, using validated modified Objective Structured Assessment of Technical Skills, assessed the individual videos. The parameters studied were: Respect for tissues, time and motion, and instrument handling for each step of laparoscopic nephrectomy (LN) (construct validity). Test-retest and interrater reliability was also evaluated. RESULTS: Twenty-four participants (4 experts and 20 nonexperts) took part in this study. The mean overall rating for the experience of TLN on TEC was 4.5 (Face Validity). The mean score for the appropriateness of TEC as a training tool for TLN was 4.6 (content validity) when evaluated by the four experts. The mean scores for the nonexperts and experts using video recordings for various variables were: Respect for tissue-1.74 (standard deviation [SD]-0.62) vs 3.63 (SD-1.06), (P<0.01), time and motion-1.74 (SD-0.58) vs 4 (SD-0.76), (P<0.01), and instrument handling-1.84 (SD-0.61) vs 4.25 (SD-0.71), (P<0.01) (construct validity). The study also suggested test-retest and interrater reliability. CONCLUSIONS: This study suggests face, content, and constructs validity and reliability of the TEC as a training tool for TLN.

The effect of divided attention on novices and experts in laparoscopic task performance.

BACKGROUND: Attention is important for the skilful execution of surgery. The surgeon's attention during surgery is divided between surgery and outside distractions. The effect of this divided attention has not been well studied previously. We aimed to compare the effect of dividing attention of novices and experts on a laparoscopic task performance. METHODS: Following ethical approval, 25 novices and 9 expert surgeons performed a standardised peg transfer task in a laboratory setup under three randomly assigned conditions: silent as control condition and two standardised auditory distracting tasks requiring response (easy and difficult) as study conditions. Human reliability assessment was used for surgical task analysis. Primary outcome measures were correct auditory responses, task time, number of surgical errors and instrument movements. Secondary outcome measures included error rate, error probability and hand specific differences. Non-parametric statistics were used for data analysis. RESULTS: 21109 movements and 9036 total errors were analysed. Novices had increased mean task completion time (seconds) (171 ± 44SD vs. 149 ± 34, p < 0.05), number of total movements (227 ± 27 vs. 213 ± 26, p < 0.05) and number of errors (127 ± 51 vs. 96 ± 28, p < 0.05) during difficult study conditions compared to control. The correct responses to auditory stimuli were less frequent in experts (68 %) compared to novices (80 %). There was a positive correlation between error rate and error probability in novices (r (2) = 0.533, p < 0.05) but not in experts (r (2) = 0.346, p > 0.05). CONCLUSION: Divided attention conditions in theatre environment require careful consideration during surgical training as the junior surgeons are less able to focus their attention during these conditions.

Comparison of endoscopic task performance with crossed versus uncrossed straight and curved instruments through a single port.

BACKGROUND: Despite advancing technology for single-incision minimal access surgery, there have been no reports on the optimal operating setup and the instruments for use through a single port. This study therefore aimed to compare task performance in single-port surgery between crossed and uncrossed instruments (straight and distally coaxially curved). METHODS: A dedicated trainer box was used to investigate the performance of two tasks (pick-transfer-place and dissection) by 18 surgical residents using two randomly allocated manipulating systems: (1) a conventional, uncrossed manipulation system (UCMS), with surgery through a cone-shaped 40-mm port using coaxially curved or straight instruments subtending a 30° manipulation angle, and (2) a crossed manipulation system (CMS), with surgery through a cylindrical miniport (25 mm) using coaxially curved instruments. RESULTS: The pick-transfer-place task performed with the UCMS enabled comparison between straight and curved coaxial instruments and showed that although the participants moved the same number of objects with either type (p = 0.464), they dropped a significantly more objects with straight instruments (1.5 ± 1.33 vs. 0.61 ± 0.85; p = 0.013). The execution of this task with the CMS (curved instruments only) provided a performance (dropped objects and error rates) equal to that obtained by the UCMS with curved instruments (p = 0.521, p = 0.989). The dissection task with the UCMS showed no difference between straight and curved coaxial instruments in dissection accuracy (75.6 vs. 75.5%; p = 0.950) or execution times (258 vs. 302 s; p = 0.367). The performance of this task by the CMS and the UCMS (with curved coaxial instruments) was equivalent with regard to dissection accuracy (p = 0.849) and execution time (p = 0.402). CONCLUSIONS: Using the UCMS, task performance is better with distally curved coaxial instruments. The CMS (with curved instruments) gives a task performance equivalent to that obtained with UCMS.

A qualitative assessment of human cadavers embalmed by Thiel's method used in laparoscopic training for renal resection.

Human cadaveric tissue is the fundamental substrate for basic anatomic and surgical skills training. A qualitative assessment of the use of human cadavers preserved by Thiel's method for a British Association of Urological Surgeons-approved, advanced laparoscopic renal resection skills training course is described in the present study. Four trainees and four experienced laparoscopic surgeons participated in the course. All participants completed a five-point Likert scale satisfaction questionnaire after their training sessions. The quality of cadaveric tissue and the training session were assessed with particular emphasis placed on the ease of patient positioning, the ease of trocar placement, the preservation of tissue planes, the ease of renal pedicle dissection, and the quality of tissue preservation. All of the participants highly rated the quality of the cadaveric tissue embalmed by Thiel's method (mean scores for quality on the five-point Likert scale were 4.5 and 4.3 by the trainees and experienced laparoscopic surgeons, respectively). All of the steps of laparoscopic renal resection were rated 4.0 or more on the Likert scale by both trainees and faculty members. The initial response rates for using a human cadaver embalmed by Thiel's method as a training tool for laparoscopic nephrectomy showed encouraging results. The performance of a laparoscopic nephrectomy on a human cadaver embalmed by Thiel's method bears close resemblance to real laparoscopic nephrectomy procedures, and thus demonstrates added advantages to the previously reported models.

Ergonomics of and technologies for single-port lapaxroscopic surgery.

BACKGROUND: There are a number of major constraints in ergonomics of and technologies for single port laparoscopic surgery. MATERIAL AND METHODS: The review is based on a complete literature search through PubMed, Medline. Single port laparoscopic surgery (SPLS), single incision laparoscopic surgery (SILS), laparoscopic single-site surgery (LESS), ergonomics, technologies, robotic SPLS, SPLS or SILS operations were the keywords used for the literature search. RESULTS AND DISCUSSION: The SPLS approach imposes several restrictions: Maintenance of sufficient exposure, sustained pneumoperitoneum, adequate retraction, collision between instruments (internal and external), collision between instruments and optics, and limited instrument manipulation and triangulation. Compensatory techniques such as using percutaneous sutures for retraction and employing coaxial, flexible, and articulating instruments have been used to improve triangulation. CONCLUSIONS: The ergonomics imposed by this approach are different from those of multi-port laparoscopic surgery. Considerable progress in port and instruments for SPLS has been achieved in the last five years in order to overcome the constraints and problems facing the operating surgeon when using the SPLS approach. Further more advanced instrumentation such as hand-held manipulators with seven degrees of freedom (DOF) and robotic devices for SPLS is needed to realize the full potential of the SPLS approach.