Initial experience with stereoscopic visualization of three-dimensional ultrasound data in surgery

Initial in vivo and in vitro experiments were performed to evaluate the feasibility of stereoscopically displaying three-dimensional (3D) ultrasound data from neurosurgery, laparoscopic surgery, and vascular surgery. Stereoscopic visualization was illustrated by four video sequences, which can be downloaded from http://www.us.unimed.sintef.no/. These sequences show a brain tumor, hepatic arteries in relation to the gallbladder, a model that mimics a neuroendoscope in a cyst, and a ``flight' into model of an artery with an intima flap. The experiments indicate that stereoscopic display of ultrasound data is feasible when there is sufficient contrast between the objects of interest and the surrounding tissue. True 3D vision improves perception, thus enhancing the ability to understand complex anatomic structures such as irregular lesions and tortuous vessels. Received: 5 August 1999/Accepted: 14 October 1999/Online publication: 22 May 2000     

The 3-D monitor and head-mounted display

Background: Stereoscopic (3-D) monitors and head-mounted displays have promised to facilitate laparoscopic surgery by increasing positional accuracy and decreasing operative time. To test this hypothesis, we evaluated the performance of subjects using these displays to perform standardized laparoscopic dexterity drills. Methods: Fifty laparoscopic novices worked within an abdominal cavity simulator using four videoscopic display configurations: (1) standard (2-D) monitor; (2) 3-D monitor; (3) 2-D head-mounted display; and (4) 3-D head-mounted display. Subjects repeated 3 standardized training exercises 2 times. We measured time to complete each drill and number of errors committed. Results: Mean total times to complete all 3 drills were 455, 459, 485, and 449 sec for configurations 1–4, respectively. Mean total errors committed numbered 11.3, 10.4, 12.3, and 10.8, respectively. Neither comparison reached statistical significance (p < 0.05). When 3-D configurations were compared to 2-D configurations overall, a small but statistically significant reduction in errors was noted for 1 drill only (4.3 vs 5.0, p= 0.018). Conclusions: Three-dimensional imaging slightly reduced the number of errors committed by laparoscopic novices during one test drill; this improvement, however, was not clinically significant. Neither the 3-D monitor nor the head-mounted display decreased task performance time. Widespread adoption of this technology awaits future improvement in display resolution and ease of use. Received: 14 October 1998/Accepted: 22 January 1999     

Clinical use of a front lifting hood rectoscope tube for transanal endoscopic microsurgery

Background: Transanal endoscopic microsurgery (TEM), a procedure developed by Buess et al. requires a specially designed surgical rectoscope system, and adequate training for its operation is mandatory. In order to simplify the performance of TEM, and to allow the use of additional surgical instruments and devices, we have developed a new rectoscope tube. Methods: The forward half of the tube can be opened longitudinally by hand. Our working insert platform is hollowed and includes a channel for an endoscope. The resection procedure can be performed under normal atmospheric pressure. This newly developed rectoscope system has already been employed clinically. TEM was performed using our original forward lifting hood rectoscope tube in 20 patients, including 12 cases of sessile adenoma and eight cases of early carcinoma. Results: The forward hood of the tube was opened to the maximum angle of 25° in eight patients and 15–20° in the other 12 patients. The visible field of the rectal interior was extended in direct proportion to the angle. Through our working insert platform, instruments and devices could be used for either laparoscopic or open surgery. Conclusions: These modifications have made TEM easier and will therefore make the procedure available to more surgeons. Received: 3 February 1997/Accepted: 1 July 1997     

Successfully establishing laparoscopic surgery programs in developing countries

Background: Laparoscopic surgery has not been widely established in developing countries due to the lack of access to training and lack of money. We describe our experience using on-site training programs to efficiently teach and propagate laparoscopic surgery in Leon, Nicaragua; La Paz, Bolivia; and Santa Cruz, Bolivia. Methods: A group of well-trained and motivated local surgeons was identified in each country as the initial target for teaching. Participants were taught basic and advanced laparoscopic surgery during on-site didactics, animal laboratories, and proctoring sessions. Follow-up courses were held until the target group of surgeons was capable of independently teaching and supervising laparoscopic surgery among other surgeons in each country. Results: Multiple technical and logistic difficulties were encountered. In Leon, Nicaragua, and La Paz, Bolivia, a total of eight surgeons were fully trained and proctored in laparoscopic cholecystectomy. In La Paz and Santa Cruz, Bolivia, a total of seven surgeons were instructed in advanced laparoscopic procedures. To date, over 180 patients have undergone laparoscopic cholecystectomy or advanced procedures with a morbidity similar to that reported in literature series in the United States. Conclusions: Our experience demonstrates that in spite of numerous limitations, basic and laparoscopic surgery can be efficiently and safely taught in developing countries. Many lessons were learned in how to safely and efficiently use laparoscopic equipment and instruments within strict financial constraints. Received: 20 March 1996/Accepted: 15 May 1996     

Telementoring

Background: Telemedicine offers significant advantages in bringing consulting support to distant colleagues. There is a shortage of surgeons trained in performing advanced laparoscopic operations. Aim: Our aim was to evaluate the role of telementoring in the training of advanced laparoscopic surgical procedures. Methods: Student surgeons received a uniform training format to enhance their laparoscopic skills and intracorporeal suturing techniques and specific procedural training in laparoscopic colonic resections and Nissen fundoplication. Subsequently, operating rooms were equipped with three cameras. Telestrator (teleguidance device), instant replay (to critique errors), and CD-ROM programs (to provide information of reference) were used as intraoperative educational assistance tools. In phase I, four colonic resections were performed with the mentor in the operating room (group A) and four colonic resections were performed with the mentor on the hospital grounds, but not in the operating room (group B). The voice and video signals were received at the mentor's location, using coaxial cable. In phase II, two Nissen fundoplications were performed with the mentors in the operating room (group C) and two Nissen fundoplications were performed with the mentors positioned five miles away from the operating room (group D), using currently existing land lines at the T-1 level. Results: There were no differences in the performances of the surgeons and outcome of the operations between groups A & B and C & D. It was possible to tackle the intraoperative problems effectively. Conclusions: The telementoring concept is potentially a safe and cost-effective option for advanced training in laparoscopic operations. Further investigation is necessary before routine transcontinental patient applications are attempted. Received: 17 May 1996/Accepted: 19 August 1996     

Technical advances toward interactive image-guided laparoscopic surgery

Background: Laparoscopic surgery uses real-time video to display the operative field. Interactive image-guided surgery (IIGS) is the real-time display of surgical instrument location on corresponding computed tomography (CT) scans or magnetic resonance images (MRI). We hypothesize that laparoscopic IIGS technologies can be combined to offer guidance for general surgery and, in particular, hepatic procedures. Tumor information determined from CT imaging can be overlayed onto laparoscopic video imaging to allow more precise resection or ablation. Methods: We mapped three-dimensional (3D) physical space to 2D laparoscopic video space using a common mathematical formula. Inherent distortions present in the video images were quantified and then corrected to determine their effect on this 3D to 2D mapping. Results: Errors in mapping 3D physical space to 2D video image space ranged from 0.65 to 2.75 mm. Conclusions: Laparoscopic IIGS allows accurate (<3.0 mm) confirmation of 3D physical space points on video images. This in combination with accurately tracked instruments and an appropriate display may facilitate enhanced image guidance during laparoscopy. Received: 30 April 1999/Accepted: 10 November 1999/Online publication: 8 May 2000     

A comparison of surgeons' posture during laparoscopic and open surgical procedures

Background: There is increasing recognition of surgeons' physical fatigue in the new ergonomic environment of laparoscopic surgery. The purpose of this study was to determine what the differences are in the movement of the surgeon's axial skeleton between laparoscopic and open operations. Methods: Surgeons' body positions were recorded on videotape during four laparoscopic (LAP) and six open (OP) operations. The percent of time the head and back were in a normal, bent, or twisted position as well as the number of changes in head and back position were tabulated using a computer program. A separate laboratory study was performed on four surgeons ``walking' a 0.5-inch polyethylene tubing forward and backward using laparoscopic and open techniques. The movements of the surgeons' head, trunk, and pelvis were measured using a three-camera kinematic system (Kin). The center of pressure was recorded using a floor-mounted forceplate (Fp). Results: In the operating room surgeons' head and back positions were more often straight in laparoscopic procedures and more often bent in open operations. The number of changes in back position per minute were significantly decreased when the laparoscopic-only part of surgery was analyzed. In the laboratory the subjects' head position was significantly (p= 0.02) more upright and the anteroposterior (AP) and rotational range of motion of the head was significantly reduced during laparoscopy. Subjects' CP was more anterior and there was a significant reduction in the AP range of motion of the CP during laparoscopy. Conclusions: Our study suggests that surgeons exhibit decreased mobility of the head and back and less anteroposterior weight shifting during laparoscopic manipulations despite a more upright posture. This more restricted posture during laparoscopic surgery may induce fatigue by limiting the natural changes in body posture that occur during open surgery. Received: 3 March 1996/Accepted: 2 July 1996     

Skills evaluation in minimally invasive surgery using force/torque signatures

Background: One of the more difficult tasks in surgical education is to teach the optimal application of instrument forces and torques necessary to facilitate the conduct of an operation. For laparoscopic surgery, this type of training has traditionally taken place in the operating room, reducing operating room efficiency and potentially affecting the safe conduct of the operation. The objective of the current study was to measure and compare forces and torques (F/T) applied at the tool/hand interface generated during laparoscopic surgery by novice (NS) and experienced (ES) surgeons using an instrumented laparoscopic grasper and to use this data for evaluating the skill level. Methods: Ten surgeons (five-NS, five-ES) performed a cholecystectomy and Nissen fundoplication in a porcine model. An instrumented laparoscopic grasper with interchangeable standard surgical tips equipped with a three-axis F/T sensor located at the proximal end of the grasper tube was used to measure the F/T at the hand/tool interface. In addition, one axis force sensor located at the grasper's handle was used to measure the grasping force. F/T data synchronized with visual view of the tool operative maneuvers were collected simultaneously via a novel graphic user interface incorporated picture-in-picture video technology. Subsequent frame-by-frame video analysis of the operation allowed a definition of states associated with different tool/tissue interactions within each step of the operation. F/T measured within each state were further analyzed using vector quantization (VQ). The VQ analysis defines characteristic sets of F/T in the database that were defined as F/T signature. Results: The magnitude of F/T applied by NS and ES were significantly different (p < 0.05) and varied based on the task being performed. Higher F/T magnitudes were applied by NS than by ES when performing tissue manipulation, whereas lower F/T magnitudes were applied by NS than by ES during tissue dissection. Furthermore, the time to complete the surgical procedure was longer for NS by a factor of 1.5–4.8 when compared to the time for ES. State analysis suggests that most of this time is consumed in an [idle] state, in which movements of the surgeon make no tissue contact. Conclusions: Preliminary data suggest that F/T magnitudes associated with the tool/tissue interactions provide an objective means of distinguishing novices from skilled surgeons. Clinical F/T analysis using the proposed technology and methodology may be helpful in training, developing surgical simulators, and measuring technical proficiency during laparoscopic surgery. Received: 4 May 1999/Accepted: 1 April 2000/Online publication: 4 August 2000     

Cost and benefit of the trained laparoscopic team

Background: In spite of the emergence of laparoscopic cholecystectomy as the gold standard for treatment of symptomatic gallstones, questions still remain regarding its overall cost effectiveness, especially at low-volume centers where operating room (OR) time and operative complications are higher. We hypothesize that the presence of a well-organized, dedicated laparoscopic OR team will improve surgical outcomes for this procedure. This study compares the operative results of an advanced and a basic laparoscopic surgeon using either a designated laparoscopic operating team or a nondesignated team. Methods: The hospital records for 71 elective laparoscopic cholecystectomies with cholangiograms were retrospectively reviewed and anesthesia times and conversion rates were analyzed. Procedures were performed either at a hospital with a dedicated laparoscopy team or a hospital with nondedicated OR personnel. All procedures were done by an advanced laparoscopic surgeon or a basic laparoscopic surgeon. Results: Case characteristics were evenly matched between sites and surgeons. The mean total anesthesia time at the dedicated site was 120.8 min, compared to 152.3 min at the nondedicated site with a mean difference of 31.5 min (p= 0.001). A 12% conversion rate was documented at the nondedicated site. There were no conversions at the site with a dedicated laparoscopy team. No major complications were encountered in this series. Conclusion: This study demonstrates that having a designated laparoscopic trained team provides a time savings to both advanced and basic laparoscopic surgeons. Although no major complications were encountered, there was a significant conversion rate for the less experienced surgeon operating without the support of a trained team. The end result from having a dedicated team in endoscopic surgery is decreased operative time, an improvement in patient care, and decreased costs to the patient and institution. Received: 5 July 1996/Accepted: 9 January 1997     

An experimental comparison of 3-dimensional and 2-dimensional endoscopic systems in a model

Purpose: This study compares the effect of new electronic display systems using endoscopic instruments on intrathoracal maneuvering and targeting under standardized conditions. A 2-dimensional (2-D) vision system is compared with 2 stereoscopic 3-dimensional (3-D) video technologies, called “shutter glasses,” and the head-mounted display (HMD) system. Methods: Fifteen participants with minor experience (<50 operations = beginners) and 15 participants with endoscopic experience (advanced) had to hit 12 electronically conducted wires in a thoracic spine model using 3 different systems (2-D video, 3-D shutter glasses, and 3-D HMD). The sequence was randomly alternated for each participant and repeated 3 times to eliminate the influence of training and concentration. Results: The execution time with the 2-D system (mean time, 95.5 seconds) was shorter than with the HMD (mean time, 107 seconds; P = .001) or the Shutter system (mean time, 101 seconds; P = .002). No significant difference was seen between the 3-D systems (P = .153). The overall look of the missed targets showed statistically no difference between the 3 systems (P = .191). None of the 3 systems showed a statistically significant correlation between execution time and number of missed targets. Regarding the total number of missed targets for advanced and beginner groups, the head-mounted display system in the advanced group showed higher but not statistically significantly higher accuracy. Conclusions: Although the 3-D systems tested for endoscopic surgery did not accelerate the execution speed, the HMD system seems to increase the accuracy for endoscopically experienced surgeons.     

Early international results of laparoscopic gastrectomies

Background: The first totally laparoscopic Billroth II gastrectomy was performed in 1992. To date, laparoscopic gastrectomy has been performed by a small number of surgeons around the world and the laparoscopic approach has been extended to Billroth I and total gastrectomy. The aim of this study is to review the state of laparoscopically performed gastrectomies in the international scene. Methods: Questionnaires were prepared and sent to every surgeon in the world known by the authors or their contacts to have performed a laparoscopic gastrectomy. A questionnaire survey was started in July 1994 and completed by November 1994. Data collected included age, sex, type of gastric resection, technique of reconstruction after resection, average duration of surgery, time to liquid and solid intake, postoperative hospital stay, complications, and opinions of the surgeons. Results: Sixteen surgeons contributed to this study. A total number of 118 cases of laparoscopic gastrectomies, comprising Billroth I (11), Billroth II (87), vagotomy and antrectomy (10), and total gastrectomy (10) had been performed. The indications were gastric and/or duodenal ulcers and benign and malignant gastric tumors. Conclusions: Laparoscopic gastrectomy was found to be superior to the open technique by 10 of 16 surgeons because of faster recovery, less pain, and better cosmesis. The procedure was an expensive and long operation according to four. Two surgeons were uncertain of any benefit because of limited experience. Received: 7 August 1996/Accepted: 28 October 1996     

Development of gallstone surgery in Germany

Background: The aim of this study was to evaluate the development and outcome of laparoscopic gallstone surgery in Germany in a nationwide representative survey. Methods: A written questionnaire, which included 111 structured items about diagnostic and therapeutic approaches, number of procedures, complications, and mortality, was sent to 449 randomly selected German surgeons (20% of the registered German general surgeons) annually from 1991 to 1994. Results: A total number of 72,455 operations for gallstone disease was reported. The frequency of laparoscopic cholecystectomies increased from 24.9% in 1991 to 65.3% in 1993. In 1994, 92% of the polled surgeons were using the laparoscopic approach as compared with 10% in 1991. The results demonstrated significantly lower morbidity (6% vs. 9%) and mortality figures (0.14–0.45%) than for the open procedure. The percentage of common bile duct (CBD) injuries was significantly higher for the laparoscopic group than for the open treatment group (0.7% vs. 0.4%). In 1993 the data shows a significant decrease in surgical complications such as bleeding, CBD injuries, and relaparotomy rate for the laparoscopic procedures. No changes were seen in the mortality rate. Conclusions: These results show learning curves that project a positive trend in the overall risk incurred by laparoscopic cholecystectomy in Germany during the past few years. This can be seen as an effect of better training and experience. Obviously, CBD injuries and technical problems especially have passed their peak of incidence. Received: 24 October 1997/Accepted: 28 August 1998     

Evaluation of two- and three-dimensional visualization for endoscopic endonasal surgery using a novel stereoendoscopic system in a novice: a comparison on a dry laboratory model

Background

Three-dimensional (3-D) stereoscopic vision is theoretically superior to two-dimensional (2-D) vision in endoscopic endonasal surgery. However, only few reports have quantitatively compared endoscopic performance under the two visual conditions. We introduced a newly designed stereoendoscopic system with a “dual-lens and single camera” for endoscopic endonasal surgery and objectively compared the performances under 3-D and high-definition 2-D visualizations on a dry laboratory model.

Methods

Thirty subjects without experience performing endoscopic surgery, computer-simulated training or any 3-D video system were recruited and divided into two groups (Group A and Group B) for performing two different tasks. The novel 4.7-mm-diameter stereoendoscope provided high-definition (HD) images. In Task 1, Group A started the task under the 3-D condition followed by the 2-D condition, and Group B vice versa. In Task 2, Group A started the task under the 2-D condition followed by the 3-D condition, and Group B vice versa. The performance accuracy and speed under the two visual conditions were analyzed.

Results

Significant improvement in performance accuracy and speed was seen under 3-D conditions in the both “3-D first” and “2-D first” subgroups during both tasks (P?<?.001). Regardless of order, the inaccuracy rate and performance time under 3-D conditions was significantly lower than that under 2-D conditions in each subject.

Conclusions

We demonstrated the advantage of 3-D visualization over 2-D visualization for inexperienced subjects. Further quantitative clinical studies are required to confirm whether stereoendoscopy actually provides benefits in clinical settings.     

Duration of postlaparoscopic pneumoperitoneum

Background: Patients who present with abdominal pain after recent laparoscopic surgery present a diagnostic dilemma when pneumoperitoneum is present. Previous studies do not define the duration of postlaparoscopic pneumoperitoneum. In this study, we attempted to define the duration of laparoscopic pneumoperitoneum and to identify factors which affect resolution time. Methods: We followed 57 patients who underwent laparoscopic cholecystectomy (34), inguinal herniorraphy (20), or appendectomy (three). Serial abdominal films were taken until all residual gas was resolved. Results: Thirty patients resolved their pneumoperitoneum within 24 h; 16 patients resolved between 24 h and 3 days; nine patients resolved between 3 and 7 days; two patients resolved between 7 and 9 days. Mean resolution time for all patients was 2.6 ± 2.1 days. There was no apparent difference in resolution time between the three types of procedures; however, the sample size may be insufficient. Duration of the pneumoperitoneum did not correlate with gender, age, weight, initial volume of CO₂ used, length of time for the procedure, or postoperative complications. Sixteen patients had bile spillage during cholecystectomy which significantly reduced the duration of postoperative pneumoperitoneum (p < 0.008), resulting in a mean resolution time of 1.3 ± 0.9 days. While 14 patients reported postoperative shoulder pain, no correlation was found between the presence or duration of shoulder pain and the extent or duration of pneumoperitoneum. Conclusions: We conclude that the residual pneumoperitoneum following laparoscopic surgery resolves within 3 days in 81% of patients and within 7 days in 96% of patients. The resolution time was significantly less in patients sustaining intraoperative bile spillage during cholecystectomy. There was no correlation found between postoperative shoulder pain and the presence or duration of the pneumoperitoneum. Received: 22 March 1996/Accepted: 12 July 1996     

Ergonomic problems associated with laparoscopic surgery

Background: The Society of American Gastrointestinal Endoscopic Surgeons (SAGES) Task Force on Ergonomics conducted a subjective and objective assessment of ergonomic problems associated with laparoscopic instrument use. The goal was to assess the prevalence, causes, and consequences of operational difficulties associated with the use of laparoscopic instruments. Methods: A questionnaire was distributed asking respondents to rate the frequency with which they experienced pain, stiffness, or numbness in several body areas after laparoscopic operations. An ergonomics station was assembled to quantify forearm and thumb muscle workload. Processed electromyogram (EMG) signals were acquired from 27 volunteer surgeon subjects while they completed simulated surgical tasks using a hemostat and an Ethicon® laparoscopic grasper, with the aid of an endoscopic trainer and video monitoring system. Results: Of 149 surgeons responding to the questionnaire, 8% to 12% reported frequent pain in the neck and upper extremities associated with laparoscopic surgery. The ergonomics station demonstrated that the peak and total muscle effort of forearm and thumb muscles were significantly greater (p < 0.01) when the grasping task was performed using the laparoscopic instrument rather than the hemostat. Conclusion: These findings indicate that laparoscopic surgical technique is more taxing on the surgeon.     

Laparoscopic cholecystectomy performed by a single surgeon using a visual field tracking camera

Background: This report describes a visual field tracking camera for laparoscopic surgery that allows the visual field to be changed without moving the laparoscope. We also report on our early experience with this camera for single-surgeon laparoscopic cholecystectomy. Methods: The visual field tracking camera has a tracking mechanism (composed of a zoom lens and a charge-coupled device [CCD] slide mechanism) built into the camera head. The 80° visual field observed with the laparoscope can be expanded using the zoom lens, and the field can be shifted by changing the size of the area being viewed by the CCD. This is accomplished by pushing a switch on the forceps or by verbal command. Cholecystectomy was carried out on 12 patients with gallstones using this camera. The operations were performed by either a single surgeon or two surgeons. Forceps held with a forceps holder were inserted through the right port to lift the fundus of the gallbladder. The single surgeon used the other two ports to resect the gallbladder by the two-handed technique. Results: In all cases, cholecystectomy was completed without any need to move the laparoscope at any point during the operation. Seven operations were performed by a single surgeon. Mainly for education purposes, five other operations were performed by a pair of surgeons. The mean time required for surgery was 76 ± 17 min. This time did not differ from that of laparoscopic cholecystectomy performed during the same period on 22 patients by teams of three surgeons using conventional cameras. Conclusions: Using the visual field tracking camera, laparoscopic cholecystectomy can be performed without any need to touch the laparoscope. This camera allowed laparoscopic cholecystectomy to be performed by a single surgeon. Received: 30 April 1999/Accepted: 10 January 2000/Online publication: 4 August 2000     

Laparoscopic Duhamel procedure

Background: Between February 1995 and June 1998, 30 laparoscopic Duhamel pull-through procedures were performed in our department. Methods: Our main aim was to prove the feasibility of the laparoscopic abdominal Duhamel procedure for different localizations of Hirschsprung disease. We used one camera port and three working ports. The sigmoid colon and posterior rectum were mobilized laparoscopically. A standard posterior colo-anal anastomosis was fashioned and a stapler was used for the anterior anastomosis. The top of the rectum was then closed by endo stapler under laparoscopic vision. Results: Thirty patients underwent laparoscopic surgery for this procedure. Three laparoscopic procedures were converted because of technical difficulties. The operative time was 100–330 mn. Oral feeding was started at a mean postoperative time of 2.5 days. Mean postoperative hospitalization was 9 days. Early postoperative complications included 1 anastomotic leak, 1 retrorectal abscess, 2 urinary infections, and 1 evisceration (after conversion). No enterocolitis or enterocolitis-like symptoms were noted. All patients now have daily spontaneous bowel movements. Conclusion: The laparoscopic Duhamel procedure can be performed safely, giving good results. Received: 6 November 1998/Accepted: 12 February 1999     

Computer-based desktop system for surgical videotape editing

Background: The educational role of surgical video presentations should be optimized by linking surgical images to graphic evaluation of indications, techniques, and results. We describe a PC-based video production system for personal editing of surgical tapes, according to the objectives of each presentation. Methods: The hardware requirement is a personal computer (100 MHz processor, 1-Gb hard disk, 16 Mb RAM) with a PC-to-TV/video transfer card plugged into a slot. Computer-generated numerical data, texts, and graphics are transformed into analog signals displayed on TV/video. A Genlock interface (a special interface card) synchronizes digital and analog signals, to overlay surgical images to electronic illustrations. The presentation is stored as digital information or recorded on a tape. Results: The proliferation of multimedia tools is leading us to adapt presentations to the objectives of lectures and to integrate conceptual analyses with dynamic image-based information. We describe a system that handles both digital and analog signals, production being recorded on a tape. Movies may be managed in a digital environment, with either an ``on-line' or ``off-line' approach. System requirements are high, but handling a single device optimizes editing without incurring such complexity that management becomes impractical to surgeons. Conclusions: Our experience suggests that computerized editing allows linking surgical scientific and didactic messages on a single communication medium, either a videotape or a CD-ROM. Received: 20 August 1996/Accepted: 30 September 1996     

Multicentric experience of the Belgian Group for Endoscopic Surgery (BGES) with endoscopic adrenalectomy

Background: Adrenalectomy is not a frequent operation. Therefore the newly developed laparoscopic approach is sporadically performed by surgeons dealing with endocrine disorders. Methods: Some 54 videoendoscopic adrenalectomies performed on 52 patients by five surgical teams between October 1993 and December 1996 were prospectively evaluated. Results: Indications for endoscopic adrenalectomy were pheochromocytoma (n= 17), primary hyperaldosteronism (n= 15), Cushing's adenoma or disease (n= 7), nonsecreting adenoma (n= 7), single metastasis from adenocarcinoma (n= 2), adenoma with dehydroepiandrostenedione (DHEAS) hypersecretion (n= 3), and ACTH-secreting metastases from a thymoma (n= 1). Of the 54 adrenalectomies performed, 31 were of the left gland, 19 of the right and two bilateral. Laparoscopic adrenalectomy was successful in 50 patients (96%). Median tumor size was 4 cm (range 1.5–12), median operation duration was 80 min (range 59–360), and median postoperative stay was 4 days (range 2–13). One patient required blood transfusion. Conclusions: Endoscopic adrenalectomy can safely be performed—even sporadically—by surgeons well versed in adrenalectomy techniques for endocrine disorders and trained in endoscopic surgery. Received: 25 March 1997/Accepted: 16 May 1997     

Laparoscopic cholecystectomy, Calot's triangle, and variations in cystic arterial supply

Background: The extrahepatic biliary tree with the exact anatomic features of the arterial supply observed by laparoscopic means has not been described heretofore. Iatrogenic injuries of the extrahepatic biliary tree and neighboring blood vessels are not rare. Accidents involving vessels or the common bile duct during laparoscopic cholecystectomy, with or without choledocotomy, can be avoided by careful dissection of Calot's triangle and the hepatoduodenal ligament. Methods: We performed 244 laparoscopic cholecystectomies over a 2-year period between January 1, 1995 and January 1, 1997. Results: In 187 of 244 consecutive cases (76.6%), we found a typical arterial supply anteromedial to the cystic duct, near the sentinel cystic lymph node. In the other cases, there was an atypical arterial supply, and 27 of these cases (11.1%) had no cystic artery in Calot's triangle. A typical blood supply and accessory arteries were observed in 18 cases (7.4%). Conclusion: Young surgeons who are not yet familiar with the handling of an anatomically abnormal cystic blood supply need to be more aware of the precise anatomy of the extrahepatic biliary tree. Received: 1 November 1998/Accepted: 22 March 1999