Elizabeth C. Hamilton

Comparison of video trainer and virtual reality training systems on acquisition of laparoscopic skills

Training on a video trainer or computer-based minimally invasive surgery trainer leads to improved benchtop laparoscopic skill. Recently, improved operative performance from practice on a video trainer was reported. The purpose of this study was three fold: (a) to compare psychomotor skill improvement after training on a virtual reality (VR) system with that after training on a video-trainer, (VT) (b) to evaluate whether skills learned on the one training system are transferable to the other, and (c) to evaluate whether VR or VT training improves operative performance. For the study, 50 junior surgery residents completed baseline skill testing on both the VR and VT systems. These subjects then were randomized to either a VR or VT structured training group. After practice, the subjects were tested again on their VR and VT skills. To assess the effect of practice on operative performance, all second-year residents (n = 19) were evaluated on their operative performance during a laparoscopic cholecystectomy before and after skill training. Data are expressed as percentage of improvement in mean score/time. Analysis was performed by Students paired t-test. The VR training group showed improvement of 54% on the VR posttest, as compared with 55% improvement by the VT group. The VR training group improved more on the VT posttest tasks (36%) than the VT training group improved on the VR posttest tasks (17%) (p <0.05). Operative performance improved only in the VR training group (p <0.05). Psychomotor skillsimprove after training on both VR and VT, and skills may be transferable. Furthermore, training on a minimally invasive surgery trainer, virtual reality system may improve operative performance during laparoscopic cholecystectomy.

Clinical predictors of leak after laparoscopic Roux-en-Y gastric bypass for morbid obesity

Background: Gastrointestinal leak is a complication of laparoscopic Roux-en-Y gastric bypass (LRYGB). Contrast studies may underdiagnose leaks, forcing surgeons to rely solely on clinical data. This study was designed to evaluate various clinical signs for detecting leakage after LRYGB. Methods: We retrospectively reviewed 210 consecutive patients who underwent LRYGB between April 1999 and September 2001. There were nine documented leaks (4.3%). Clinical signs between patients with leaks (group 1) and those without leaks (group 2) were compared using univariate and multivariate logistic regression analysis. Results: Evidence of respiratory distress and a heart rate exceeding 120 beats per min were the two most sensitive indicators of gastrointestinal leak. Routine upper gastrointestinal contrast imaging detected only two of nine leaks (22%). Conclusion: Leak after LRYGB may be difficult to detect. Evidence of respiratory distress and tachycardia exceeding 120 beats per min may be the most useful clinical indicators of leak after laparoscopic Roux-en-Y gastric bypass.

Routine Upper gastrointestinal gastrografin® swallow after laparoscopic Roux-en-Y gastric bypass

Background: Upper gastrointestinal (UGI) swallow radiographs following laparoscopic Roux-en-Y gastric bypass (LRYGBP) may detect an obstruction or an anastomotic leak. The aim of our study was to determine the efficacy of routine imaging following LRYGBP. Methods: Radiograph reports were reviewed for 201 consecutive LRYGBP operations between April 1999 and June 2001. UGI swallow used Gastrografin®, static films, fluoroscopic video, and a delayed image at 10 minutes. Mean values with one standard deviation were tested for significance (P<0.05) using the Mann-Whitney U test statistic. Results: Of 198 available reports, UGI detected jejunal efferent (Roux) limb narrowing (n=17), partial obstruction (n=12), anastomotic leak (n=3), complete bowel obstruction (n=3), diverticulum (n=1), hiatal hernia (n=1), and proximal Roux limb narrowing (n=1). A normal study was reported in 160 cases (81%). Partial obstruction resolved without intervention. Complete obstruction required re-operation. Compared to 6 patients who developed delayed leaks, early identification of a leak by routine UGI swallow resulted in a shorter hospital stay (mean 7.7±1.5 days vs 40.2±12.3 days, P<0.03). Conclusions: Early intervention after UGI swallow may lessen morbidity. Routine UGI swallow following LRYGBP does not obviate the importance of close clinical follow-up.

Intraoperative ultrasound and prophylactic ursodiol for gallstone prevention following laparoscopic gastric bypass

Background: Previous studies have shown that ursodiol decreases gallstone formation from 32% to 2% following open gastric bypass, but no data exist on laparoscopic Roux-en-Y gastric bypass (LRYGB) using intraoperative ultrasound (IOUS) screening. Methods: LRYGB with IOUS were performed on 195 consecutive patients. Patients with gallstones underwent simultaneous cholecystectomy, and patients without gallstones were prescribed ursodiol, 300 mg twice daily, for 6 month. Follow-up survey and ultrasound. Results: Of 195 patients, 44 (23%) had had a prior cholecystectomy, 21 (11%) underwent a simultaneous cholecystectomy, 129 (66%) had gallbladders left intact, and one (0.5%) false negative IOUS was excluded. Of 69 patients with ultrasound and survey follow-up (mean, 10 months), 19 (28%) developed gallstones seven with symptoms), and 50 (72%) were gallstone free. Forty-one percent of patients were compliant with ursodiol. There was no difference in compliance between patients with and without gallstones. In patients with gallstones, all of the symptomatic patients were noncompliant, whereas none of the compliant patients developed symptoms. Medication side-effects occurred in 17 of 69 patients (25%). Conclusions: IOUS during LRYGB efficiently screens for gallstones, and selective cholecystectomy followed by prophylactic ursodiol results in low morbidity. Improvements in compliance may lower the incidence of postoperative gallstone formation.

Surgeon workload and motion efficiency with robot and human laparoscopic camera control

AbstractsBackground: Surgeons are now being assisted by robotic systems in a wide range of laparoscopic procedures. Some reports have suggested that robot-assisted camera control (RACC) may be superior to a human driver in terms of quality of view and directional precision, as well as long-term cost savings. Therefore, we setout to investigate the impact of RACC of surgeon motion efficiency. Methods: Twenty pigs were randomized to undergo a standardized laparoscopic Nissen fundoplication with either a human or RACC system, the AESOP 2000. All procedures were performed by the same surgical fellow. Time was recorded for dissection and suture phases. Inertial motion sensors were used to monitor both the surgeons hands and the camera. Digitized data were analyzed to produce summary measures related to overall motion. Results: The operative times were slightly longer with RACC (mean 80.2 ± 20.6 vs 73.1 ± 15.4 min, not significant). With regard to operative times and surgeon motion measures, the only statistically significant differences were for setup and breakdown times, which contributed <15% to the total time for the procedure. Conclusion: In terms of impact on surgeon motion efficiency and operative time under normal surgical conditions, RACC is essentially the same as an expert human driver. However, careful planning and structuring of the surgical suite may yield some small gains in operative time.

Metabolic syndrome phenotype in very obese women

Severe obesity is increasingly common in the United States. Very obese persons are at increased risk for the metabolic consequences of obesity. A common multidimensional risk condition associated with obesity is the metabolic syndrome. It is accompanied by increased risk for cardiovascular disease and type 2 diabetes. Clinical manifestations of the metabolic syndrome can vary among obese individuals depending on ethnicity and gender. This study was carried out to determine the pattern of metabolic risk factors in very obese women who were considered candidates for bariatric surgery. Twenty-eight women of this type were compared to 28 nonobese women. Among the former, 11 had categorical hyperglycemia (type 2 diabetes), and 26 had metabolic syndrome by current criteria. Both those with and without diabetes had higher triglycerides and lower high-density lipoprotein (HDL) cholesterol levels than nonobese, but their levels were not categorically abnormal. These changes may have been related to observed lower postheparin lipoprotein lipase activities and higher hepatic lipase activities. In spite of lipid changes, apolipoprotein B levels were only marginally higher in very obese women. In contrast to small changes in lipoprotein metabolism, the obese women were severely insulin resistant, as indicated by hyperglycemia and elevated insulin levels. In addition, they had very high C-reactive protein levels. Thus, the metabolic syndrome, which appears to be typical of very obese women, is characterized by insulin resistance, glucose intolerance and a proinflammatory state. Atherogenic dyslipidemia as a metabolic risk factor in contrast is relatively mild. This pattern is more likely to lead to type 2 diabetes prior to development of clinically evident cardiovascular disease.