G. B. Hanna

E.A.E.S. multicenter prospective randomized trial comparing two-stage vs single-stage management of patients with gallstone disease and ductal calculi.

AbstractBackground: 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.

Randomised study of influence of two-dimensional versus three-dimensional imaging on performance of laparoscopic cholecystectomy

BACKGROUND Several three-dimensional video-endoscopic systems have been introduced to enhance depth perception during minimum-access surgery. However, there is no conclusive evidence of benefit, and these systems are more expensive than conventional two-dimensional systems. We undertook a prospective randomised comparison of two-dimensional and three-dimensional imaging in elective laparoscopic cholecystectomy for symptomatic gallstone disease. METHODS The operations were done by four specialist registrars as part of their higher surgical training. 60 operations were randomised for execution by either two-dimensional or three-dimensional imaging display (30 by each method). The degree of difficulty of the operation was graded by a consultant surgeon on a standard grading system. The primary endpoints were execution time and the errors made during the procedure. The secondary endpoints were subjective assessment of the image quality and adverse effects on the surgeon. FINDINGS There was no difference between the two-dimensional and three-dimensional display groups in median execution time (3160 [IQR 2735-4335 vs 3100 [2379-3710] s; p = 0.2) or error rate (six vs six). Surgeons reported adverse symptoms immediately after the operations with both systems. The scores for visual strain, headache, and facial discomfort were higher with the three-dimensional system. INTERPRETATION With the current technology, three-dimensional systems based on sequential imaging show no advantage over two-dimensional systems in the conduct of laparoscopic cholecystectomy.

Mechanical properties of the human abdominal wall measured in vivo during insufflation for laparoscopic surgery

BackgroundCarbon dioxide insufflation of the peritoneal cavity for laparoscopic surgery offers a unique opportunity to measure some mechanical properties of the human abdominal wall that hitherto have been difficult to obtain.MethodsThe movement and change of the abdominal wall during insufflation to a pressure of 12 mmHg was studied in 18 patients undergoing laparoscopic surgery using a remote motion analysis system that does not compromise the sterility of the operative filed. These data together with the known abdominal wall thickness of each patient (measured by preoperative ultrasound scanning) enabled estimates of mechanical stiffness.ResultsThe findings showed that the abdominal wall changes from a cylinder to a dome during inflation, and that its area is increased by 15%. A volume, averaging 1.27 × 10−3m3, results from expansion, reshaping of the abdominal wall, and displacement of the diaphragm. The abdominal wall is stiffer in the transverse plane than in the sagittal plane (Young’s modulus, 42.5 ± 9.0 kPa vs 22.5 ± 2.6 kPa; p = 0.03; paired t-test).ConclusionsMeasurements of mechanical properties of the abdominal wall in patients undergoing laparoscopic surgery were obtained using a remote motion analysis system.

Influence of the optical axis-to-target view angle on endoscopic task performance

AbstractBackground: 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.

Influence of handle design on the surgeon's upper limb movements, muscle recruitment, and fatigue during endoscopic suturing

Background: Thus far, little has been done to investigate the kinematics (motion analysis) and kinetics (muscle work, muscle fatigue, comfort) of surgeons during laparoscopic surgery. Therefore, we set out to study these ergonomic aspects of task performance in the dominant upper limb of surgeons during endoscopic suturing. Methods: Three different handles-conventional finger loop, rocker, and ball handle prototype-were compared in a study involving 10 surgeons suturing porcine enterotomies with each of the three instruments. The endpoints were performance parameters, motion analysis and muscle work, and fatigue of the surgeons dominant upper limb; subjective scores for comfort level and maneuverability were also elicited from the subjects. Results: Task quality and efficiency during endoscopic suturing, were significantly better with the ball and rocker handle needle drivers than with the finger loop instrument, with lower angular velocity at the elbow and shoulder joints, more pronation, and less supination. The integrated muscle work was much lower for both the rocker and the ball handles. Significant muscle fatigue, especially of the arm flexors and deltoid, was observed only with finger loop instruments. Comfort and maneuverability rating scores were higher with both handles than with the conventional finger loop. The ball handle was easier to maneuver, but it was somewhat less comfortable than the rocker system. Conclusion: A different pattern of joint movements, a reduction in muscle power exerted during endoscopic suturing, and hence an absence of muscle fatigue were documented with ergonomic needle drivers (rocker and ball) when compared to the conventional finger loop instruments. These differences translate to better and more efficient task performance with enhanced comfort.

Computer-controlled endoscopic performance assessment system

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.

Optimal port locations for endoscopic intracorporeal knotting

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 surgeons 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.

Ergonomic principles of task alignment, visual display, and direction of execution of laparoscopic bowel suturing

Background: Laparoscopic suturing is technically a demanding skill in laparoscopic surgery. Ergonomic experimental studies provide objective information on the important factors and variables that govern optimal endoscopic suturing. Our objective was to determine the optimum physical alignment, visual display, and direction of intracorporeal laparoscopic bowel suturing using infrared motion analysis and telemetric electromyography (EMG) systems. Methods: Ten surgeons participated in the study; each sutured 50-mm porcine small bowel enterotomies toward and away from the surgeon in the vertical and horizontal bowel plane with either isoplanar (image display corresponds with actual lie of the bowel) or nonisoplanar (bowel displayed horizontally but mounted vertically in the trainer and vice versa) display. The end points were the placement error score, execution time, leakage pressure, motion analysis, and telemetric EMG parameters of the surgeons dominant upper limb. Results: Suturing was demonstrably easier in the vertical than in the horizontal plane, resulting in a better task quality (placement error score, p < 0.0001; leakage pressure, p < 0.005) and shorter execution time (p < 0.05). Nonisoplanar display of the surgical anatomy degrades performance in terms of both task efficiency and task quality. On motion analysis, a wider angle of excursion and lower angular velocity were observed during the vertical suturing with isoplaner display. Compared to horizontal suturing, supination at the wrist was significantly greater during vertical than horizontal suturing (p < 0.05). Within each category (vertical vs horizontal suturing), the direction of suturing (toward/away from the surgeon) did not influence the extent of pronation/ supination at the wrist. In line with the degraded performance, significantly more muscle work was expended during horizontal suturing. This affected the forearm flexors (p < 0.05), arm flexors and extensors (p < 0.005 and p < 0.05, respectively), and deltoid muscles (p < 0.005) and was accompanied by significantly more fatigue in the related muscles. Small bowel enterotomies sutured toward the surgeon in both the vertical and the horizontal planes exhibited less placement error score than when sutured away from the surgeon, with no significant difference in the motion analysis and EMG parameters. Conclusions: Optimal laparoscopic suturing (better task quality and reduced execution time) is achieved with vertical suturing toward the surgeon with isoplanar monitor display of the operative field. The poorer task performance observed during horizontal suturing is accompanied by more muscle work and fatigue, and it is not improved by monitor display of the enterotomy in the vertical plane.

Influence of Two-dimensional and Three-dimensional Imaging on Endoscopic Bowel Suturing

Abstract. Several three-dimensional (3-D) video-endoscopic systems have been introduced in surgical practice to enhance depth perception during minimal access surgery (MAS), but the facilitation of endoscopic manipulations by the current 3-D systems remains unproved. The aim of the study was to investigate the influence of 2-D and 3-D imaging modalities on intracorporeal suturing. The standard task consisted of suture closure of 60 mm enterotomies made in porcine small bowel with continuous seromuscular 3/0 Polysorb. Ten experienced surgeons participated in the study. The imaging systems were Storz (2-D), Welch Allyn (3-D), and Zeiss (as both 2-D and 3-D). Each surgeon performed two tasks with each modality in a random sequence. The outcome measures were execution time, suture line leakage pressure, and suture placement score. In addition, the participating surgeons assigned subjective scores on the image quality and the adverse effects of the imaging systems. There was no significant difference in the execution time, leakage pressure, and suture placement score among the various imaging modalities. Depth perception was rated as similar with 2-D and 3-D imaging. Surgeons experienced visual strain with the three systems, but it was rated higher with 3-D imaging. With the current technology, we have not documented any significant difference in task efficiency and quality of endoscopic bowel suturing by trained surgeons between 2-D and 3-D imaging systems.

Image display technology and image processing.

Significant developments in video imaging have taken place but further progress is needed to provide images with the right characteristics for optimal interpretation by the operator. The nature and location of the image display in relation to the surgeon and operating field are also important in facilitating image-guided surgery/interventions, and several new technologies are being explored. In the diagnostic field, virtual reality surface anatomical and internal luminal rendering has opened a new chapter in diagnosis, screening, and treatment planning, the potential of which is only just being realized.