Notes: Abstract Background: The design of the handle on instruments for endoscopic surgery determines comfort and efficiency of use by the surgeon. This applies particularly to needle drivers. Methods: A novel rocker handle was designed to provide holding comfort and intuitive function. This rocker handle was compared with a finger-loop handle in a study involving 10 surgeons who tied a total of 360 intracorporeal surgeons' knots in a random sequence. The end points in this study were the execution time, knot quality, and motion analysis parameters of the surgeon's elbow and shoulder joints. Results: Intracorporeal surgeon's knots tied with the rocker-handle driver exhibited a better knot quality, although this was not significant (p= 0.097). A significant improvement in the knot quality score (KQS) was observed between the first and the second sessions (p= 0.045) with the rocker handle, whereas no significant learning effect was observed for the finger-loop handle. During intracorporeal knot tying, the angular velocity at the elbow and shoulder joints was consistently lower with the rocker handle, suggesting that more controlled movements are enacted by the surgeon with this handle. Discomfort from finger-loop pressure on the thumb was reported by 3 of 10 surgeons with the finger-loop handle, whereas no discomfort was reported for the rocker handle. Conclusions: The new rocker handle improves the quality of task performance by eliminating discomfort and reducing angular velocities at the shoulder and elbow joints during use.

Notes: Abstract Background: There is little reported information on psychomotor performance in relation to minimal access surgery (MAS). Methods: A microprocessor-controlled endoscopic psychomotor tester (the Dundee Endoscopic Psychomotor Tester—DEPT) has been developed to evaluate psychomotor aspects of MAS. Experiments were conducted on 20 medical undergraduates to evaluate accuracy and reliability of the tester. Results: The study demonstrated a significant difference between subjects (p 〈 0.01). It also identified three individuals who enacted 16, 22, and 40 errors while the majority (85%) sustained less errors with a median of 4.5. Conclusions: DEPT provides a standard, reproducible, objective real-time scoring system. It identifies individuals who cannot adjust to endoscopic viewing and therefore manipulate from endoscopic images.

Notes: Abstract Background: Skin burns and ignition of drapes have been reported with the use of cold light sources. The aim of the study was to document the temperature generated by cold light sources and to correlate this with the total radiated power and infrared output. Methods: The temperature, total radiated power, and infrared output were measured as a function of time at the end of the endoscope (which is inserted into the operative field) and the end of the fiber optic bundle of the light cable (which connects the cable to the light port of the endoscope) using halogen and xenon light sources. Results: The highest temperature recorded at the end of the endoscope was 95°C. The temperature measured at the optical fiber location of the endoscope was higher than at its lens surface (p 〈 0.0001). At the end of the fiber optic bundle of light cables, the temperature reached 225°C within 15 s. The temperature recorded at the optical fiber location of all endoscopes and light cables studied rose significantly over a period of 10 min to reach its maximum (p 〈 0.0001) and then leveled off for the duration of the study (30 min). The infrared output accounted only for 10% of the total radiated power. Conclusions: High temperatures are reached by 10 min at the end of fiber optic bundle of light cables and endoscopes with both halogen and xenon light sources. This heat generation is largely due to the radiated power in the visible light spectrum.

Notes: Abstract. Port location is crucial for endoscopic manipulations. The aim of the study was to investigate the influence of manipulation, azimuth, and elevation angles of instruments on endoscopic intracorporeal knotting. The standard task was tying a surgeon's knot. Manipulation angles of 30°, 45°, 60°, 75°, and 90° with equal and unequal azimuth angles and elevation angles of 0°, 30°, and 60° were investigated. The endpoints were the execution time and parameters of knot analysis. The execution time was shorter with 60° than with either 90° or 30° manipulation angles (p 〈 0.0001 and p 〈 0.01). Equal azimuth angles resulted in a shorter execution time than wide unequal angles (p 〈 0.001). A combination of 60° manipulation angle with 60° elevation angle had the shortest execution time (p 〈 0.001) and highest performance quality score (p 〈 0.02). A range of 45°–75° manipulation angles with equal azimuth angles is recommended. As the manipulation angle increases, the elevation angle has to increase accordingly.

Notes: Abstract. We have devised an advanced computer-controlled system (ADEPT) for the objective evaluation of endoscopic task performance. The system's hardware consists of a dual gimbal mechanism that accepts a variety of 5.0-mm standard endoscopic instruments for manipulation in a precisely mapped and enclosed work space. The target object consists of a sprung base plate incorporating various tasks. It is covered by a sprung perforated transparent top plate that has to be moved and held in the correct position by the operator to gain access to the various tasks. Standard video endoscope equipment provides the visual interface between the operator and the target-instrument field. Different target modules can be used, and the level of task difficulty can be adjusted by varying the manipulation, elevation, and azimuth angles. The system's software is designed to (a) prompt the surgeon with the information necessary to perform the task, (b) collect and collate data on performance during execution of specified tasks, and (c) save the data for future analysis. The system was alpha and beta tested to ensure that all functions operated correctly.

Notes: Abstract Background: The location of the optical port and the choice of endoscope determine the angle subtended between the optical axis of the endoscope and the plane of the operation target: the optical axis-to-target view (OATV) angle. The aim of the study was to investigate the influence OATV angle on endoscopic task performance. Methods: The Dundee Endoscopic Psychomotor Tester was used for objective assessment of endoscopic task performance. Ten surgeons carried out a standard task with the optical axis of the endoscope subtending 90°, 75°, 60° and 45° to the target surface. Each subject underwent three test sessions. Each session consisted of one run with each of the OATV angles in a random order. The outcome measures were the errors rate, the execution time, and the force applied on the target. Results: The 90° OATV angle had the best accuracy, the shortest execution time, and the lowest force applied on the back plate. The errors rate increased from 17% with the 90° OATV angle to 79% with the 45° angle. There was a significant increase in execution time and force with the decrease in the OATV angle (p 〈 0.0001). Conclusions: The best task performance is obtained when the optical axis of the endoscope is perpendicular to the target plane.

Notes: Abstract Background: There are times during endoscopic procedures when the surgeon has to operate ahead of the camera/telescope assembly. As a result, the image displayed on the monitor will be an inverted mirror image of the operative field (reverse alignment). The present study addresses the extent of these difficulties and suggests some techniques that may be used to overcome the problem. Methods: Eight specialist registrars participated in experiments involving the execution of a simulated dissection task under 12 different imaging conditions. These conditions included normal alignment, reverse alignment, total or partial digital correction of reverse alignment (about the horizontal and vertical axes independently and together), and a simple rotation of the camera through 180°. Normal, reverse, and corrected reverse alignment were also tested with optical axes of 45° and 60°. The endpoints were the task execution and the errors rate. Results: A marked deterioration in execution time was observed when the surgeons worked under reverse alignment rather than under normal viewing (p= 0.036). Significant improvement in execution-time errors rate was found when both the horizontal and vertical axes were digitally corrected simultaneously (p= 0.27) and when the camera was rotated 180° with respect to the telescope during reverse alignment (p= 0.28). Conclusions: The effect on performance produced by reverse alignment of the endoscope and instruments can be overcome by means of digital electronic processing, or simply by turning the camera through 180°.

Notes: Abstract Background: The current management of patients with gallstone disease and ductal calculi consists of endoscopic stone extraction (ESE) followed by laparoscopic cholecystectomy (LC). Following the advent of techniques of laparoscopic ductal stone clearance, an alternative single-stage laparoscopic treatment was introduced for these patients. The European Association of Endoscopic Surgery (E.A.E.S.) set up a ductal stone trial to compare the relative efficacy and outcome of these two management options. Methods: A prospective randomized controlled clinical trial compared two management options. Group A (n= 150) received preoperative endoscopic retrograde cholangiography (ERC) with ESE followed by LC during the same hospital admission, and group B (n= 150) received single-stage laparoscopic management. Results: There were no significant differences between the two groups in the clinical demographic details and the pretreatment biochemical findings. In group A, 14 of 150 patients received single-stage treatment; in group B, 17 of 150 were managed by the two-stage approach (protocol violation = 31/300, 10%). In group A patients managed in accordance with randomization, ERC was successful in 129/136 (95%) and preoperative ESE succeeded in 82/98 (84%) with ductal calculi detected by the ERC. Two patients had malignancies and one refused surgery. Thus, 133 patients underwent surgery. Of this group, 116 had LC only and 17 had LC and attempted laparoscopic duct exploration. There were eight conversions to open surgery (6%), 17 complications for both stages (12.8%), and two postoperative deaths (1.5%). In group B patients managed in accordance with randomization, intraoperative cholangiography was successful in 132/133 (99%). Twenty-one (16%) had normal findings, ductal calculi were found in 109, and other pathology was noted in two (periampullary cancer, severe pancreatitis). These two patients and one other (who had gross adhesion in the triangle of Calot) were converted at the start of the procedure. Transcystic ductal stone clearance was successful in 45 of 56 patients (80%), and laparoscopic direct common duct (CBD) exploration was successful in 47 of 55 patients (85%). This group includes 53 patients who underwent primary direct exploration and two failed attempts at transcystic extraction. The conversion rate was 13%. Postoperative complications were encountered in 21 patients (15.8%), and one patient died of a major myocardial infarction (0.75%). The one postoperative death and the 10/11 biliary complications occurred in the laparoscopic supraduodenal CBD exploration subgroup. The conversion rate was higher in group B (17 vs eight; p= 0.08). Laparotomy in the postoperative period was required in three patients in group A and four patients in group B. The group B patients were in hospital for 3 days less than patients who had two-stage management (median, 6.0, IQR = 4.25–12 vs median, 9.0, IQR = 5.5–14; p 〈 0.05). Conclusions: The results demonstrate equivalent success rates and patient morbidity for the two management options but a significantly shorter hospital stay with the single-stage laparoscopic treatment. The findings indicate that in fit patients (ASA I and II), single-stage laparoscopic treatment is the better option, and preoperative ESE should be confined to poor-risk patients—i.e., those with cholangitis or severe pancreatitis.