Iyad Hassan

Negative stress-coping strategies among novices in surgery correlate with poor virtual laparoscopic performance†‡

This study explored the impact of habitual stress‐coping strategies on the laparoscopic performance of novices in surgery using a virtual reality simulator.

Spatial perception predicts laparoscopic skills on virtual reality laparoscopy simulator

ObjectsThis study evaluates the influence of visual-spatial perception on laparoscopic performance of novices with a virtual reality simulator (LapSim®).Materials and methodsTwenty-four novices completed standardized tests of visual-spatial perception (Lameris Toegepaste Natuurwetenschappelijk Onderzoek [TNO] Test® and Stumpf–Fay Cube Perspectives Test®) and laparoscopic skills were assessed objectively, while performing 1-h practice sessions on the LapSim®, comprising of coordination, cutting, and clip application tasks. Outcome variables included time to complete the tasks, economy of motion as well as total error scores, respectively.ResultsThe degree of visual-spatial perception correlated significantly with laparoscopic performance on the LapSim® scores. Participants with a high degree of spatial perception (Group A) performed the tasks faster than those (Group B) who had a low degree of spatial perception (p = 0.001). Individuals with a high degree of spatial perception also scored better for economy of motion (p = 0.021), tissue damage (p = 0.009), and total error (p = 0.007).ConclusionAmong novices, visual-spatial perception is associated with manual skills performed on a virtual reality simulator. This result may be important for educators to develop adequate training programs that can be individually adapted.

Successful Treatment of Solid-Pseudopapillary Tumor of the Pancreas with Multiple Liver Metastases

The solid-pseudopapillary tumor (SPT) is a very rare pancreatic neoplasm that predominantly affects young females. About 450 cases have been described in the world literature and approximately 20% of the reported patients were children. The occurrence of SPT with distant metastases in children is extremely rare with only two previously reported cases. We now report a 16-year-old Asian girl with a large SPT and synchronous multiple liver metastases who was successfully treated in a 2-step strategy, including initial pylorus-preserving partial duodenopancreatectomy, right hemicolectomy, resection and allografting of the portal vein and secondary resection of 12 liver metastases. The patient is disease free after a follow-up of 18 months after resection of the primary tumor, suggesting that an aggressive surgical treatment might also be justified for metastasized SPT.

The Impact of Self-Belief on Laparoscopic Performance of Novices and Experienced Surgeons

BackgroundIn many professions, nontechnical aspects such as motivation or coping with stress are known to influence performance, success, and outcome. These qualities are assessed and trained in novices for quality and safety reasons. This study explored the impact of self-belief of surgeons on laparoscopic performance using a virtual reality simulator (LapSim®).MethodsEighteen inexperienced surgical residents (with less than ten laparoscopic procedures performed) and 22 advanced residents (with more than 50 laparoscopic procedures performed) filled out a ten-item questionnaire used for the assessment of the individual sense of general self-efficacy (GSE). Afterward the participants were asked to perform three defined tasks on the LapSim, each at two different levels of difficulty. The tasks consisted of coordination, dissection, and application of clips. To assess laparoscopic performance, the total time to complete the tasks, economy of motion, and damage parameters were analyzed and correlated with the GSE score by means of Bravis-Pearson correlation analysis.ResultsIn novices, high GSE scores correlated with more errors and poor economy of motion, while in advanced residents, laparoscopic performance was independent of the level of assessed self-efficacy.ConclusionIn a small sample, high self-belief does not predict success. In novices it negatively correlates with laparoscopic skills, while in advanced residents it is independent of laparoscopic performance. Thus, training aspects seem to be of greater importance for laparoscopic skills. Nevertheless, nontechnical aspects like self-belief, motivation, stress-coping strategies, judgment, decision-making, and leadership should be included in the surgical curriculum.

DIAGNOSTIC SCORE IN APPENDICITIS. VALIDATION OF A DIAGNOSTIC SCORE (ESKELINEN SCORE) IN PATIENTS IN WHOM ACUTE APPENDICITIS IS SUSPECTED

Background and aimAt times, the diagnosis of acute appendicitis may be difficult. However, for minimum morbidity to be obtained, early and accurate diagnosis is essential. This study aimed to validate a scoring system proposed by Eskelinen et al. as an aid in making the diagnosis of appendicitis.Patients and methodsThe prospectively documented data of a consecutive series of 2,359 patients admitted for suspicion of appendicitis were used for validation. Accuracy and positive predictive value were defined as the main overall performance parameters, as was the rate of unnecessary operations to assess changes of patient management. Overall performance was assessed by receiver–operator characteristics (ROC) analysis.ResultsOf 2,359 patients, 662 were proven to have acute appendicitis (prevalence of 28%). The overall sensitivity, specificity, positive and negative predictive value, and accuracy of the score were 0.79, 0.85, 0.68, 0.91 and 0.835 at a cut-off value of 55. Calibration of the score’s cut-off value to 57 yielded more favourable results (0.72, 0.91, 0.76, 0.9 and 0.86), and the rate of unnecessary operations declined from 26.6% to 15.4% (P<0.05, χ2). ROC analysis revealed an area index of 0.91.ConclusionThe Eskelinen score delivered acceptable clinical results only after calibration to a cut-off value of 57. The data from this study suggest the investigation of whether a calibrated score might be particularly instrumental in the pre-admission evaluation of the patient in whom appendicitis is suspected.

Novices in surgery are the target group of a virtual reality training laboratory.

Background: This study aims to establish which physicians represent the suitable target group of a virtual training laboratory. Methods: Novices (48 physicians with fewer than 10 laparoscopic operations) and intermediate trainees (19 physicians who performed 30–50 laparoscopic operations) participated in this study. Each participant performed the basic module ‘clip application’ at the beginning and after a 1-hour short training course on the LapSim®. The course consisted of the tasks coordination, lift and grasp, clip application, cutting with diathermy and fine dissection at increasing difficulty levels. The time taken to complete the tasks, number of errors, and economy of motion parameters (path length and angular path) were analyzed. Results: Following training with the simulator, novices completed the task significantly faster (p = 0.001), demonstrated a greater economy of motion [path length (p = 0.04) and angular path (p = 0.01)]. In contrast, the intermediate trainees showed a reduction of their errors, but without reaching statistical significance. They showed no improvement in economy of motion and completed the task significantly slower (p = 0.03). Conclusion: Novices, in comparison to intermediate trainees, tend to benefit most during their first exposure to a laparoscopy simulator.

Paneling human thyroid cancer cell lines for candidate proteins for targeted anti‐angiogenic therapy

Tumor angiogenesis is believed to result from an imbalance of pro‐ and anti‐angiogenic factors, some of which are candidates for targeted therapy. Such therapy has raised hopes for patients with undifferentiated thyroid carcinomas, who are facing a grave prognosis with a survival of only months. In this study, in vivo growth of xenografted human thyroid carcinomas unexpectedly responded quite differently to neutralizing anti‐vascular endothelial growth factor (VEGF) antibody. In particular, lasting inhibition as well as accelerated growth occurred after treatment. Consequently, a panel of anti‐angiogenic factors was addressed in a representative sample of thyroid carcinoma lines. VEGF, fibroblast growth factor (FGF‐2), and endostatin were demonstrated by Western blotting and EIA, whereas PDGF‐A, PDGF‐B, and IL‐6 were negative. Quantification of VEGF, FGF‐2, and endostatin revealed a wide range of concentrations from 500 to 4,200 pg/ml VEGF, 5 to 60 pg/ml FGF‐2, and 50 to 300 pg/ml endostatin, not related to a particular histologic thyroid carcinoma background. Angiostatin (kringles 1–3) was detected in all, but one of the cell lines. Finally, aaATIII was confirmed in FTC133 cells. These data highlight the complex regulation of angiogenesis in thyroid carcinoma cell lines and suggest that the array of angiogenic factors differs markedly between individual cell lines. For the first time, angiostatin, endostatin, and possibly also aaATIII are identified as novel candidate regulators of angiogenesis in thyroid carcinoma cells. J. Cell. Biochem. 98: 954–965, 2006.

Functional thyrotropin receptor attenuates malignant phenotype of follicular thyroid cancer cells

Thyrotropin (TSH) is a thyroid-specific growth factor inducing differentiated function and growth of thyrocytes in vitro. In thyroid cancer, loss of TSH-receptor (TSHR) expression is a sign of de-differentiation and is believed to contribute to the malignant phenotype. The present studies aimed to determine the in vitro and in vivo effects of functioning tSHR in the follicular thyroid cancer cell line HTC, a subclone of FTC133 cells, lacking endogenous expression of TSHR, and HTCtshr+cells transfected with human TSHR-cDNA. HTCtshr+cells grew faster in vitro (doubling time 1.15 vs 1.56 d, p<0.05) and TSH caused a dose-dependent growth response. Adhesion to and invasion through reconstituted basement membrane were reduced in HTCtshr+cells, but when stimulated with TSH increased to levels comparable to naïve HTC cells. In vivo, tumor latency was 11 d for naïve HTC as compared to 21 d for HTCtshr+xenografts. Smaller tumor volumes were registered for HTCtshr+cells (250±217 vs 869±427 mm3, p<0.05). Angiogenesis, as determined by vascular surface density density (VSD) of experimental tumors, was enhanced in naïve HTC tumors (VSD 0.87±0.1 μm−1 vs 0.55±0.2μm−1 in HTCtshr+, p<0.05). VEGF secretion was more pronounced in naïve HTC cells stimulated with EGF, than in HTCtshr+cells stimulated with either TSH or EGF. In conclusion, regained expression of functional TSHR in the follicular thyroid cancer cell line HTC alters in vitro features commonly associated with the malignant phenotype. Smaller tumors and reduced angiogenesis of xenotransplanted HTC cells with functioning TSHR suggest a less aggressive in vivo phenotype. The present data highlight the pivotal role of TSHR to affect transformed thyrocytes in vitro and in vivo. They also suggest a role for EGF as a modulator of angiogenesis in thyrocytes devoid of TSHR.

Clinical background is required for optimum performance with a VR laparoscopy simulator.

Objective: To determine the role of clinical background when assessing the learning effect using a virtual-reality (VR) laparoscopy simulator (LapSim®). Materials and methods: Test subjects were 12 final-year medical students (Group A) and 12 inexperienced residents (Group B) with no previous experience of VR simulators. First, to establish a baseline, both groups performed the “clip application” task twice. They then completed a training program of increasing difficulty (coordination, cutting and clip application), after which both groups were re-tested using a difficult level of the “cutting” task as an endpoint measurement. Time to complete the tasks, as well as trauma and precision parameters, were scored. Results: Before training, times to complete the baseline task, as well as parameters of trauma and precision, were similar for both groups. After training, Group B (residents) completed the cutting task significantly faster than Group A (students). However, the former group also showed significant improvement in trauma and precision parameter scores in the endpoint measurement. Conclusion: These results suggest that clinical background and understanding of the clinical value of a training program lead to faster acquisition and improvement of laparoscopic skills as performed on the laparoscopy simulator. Thus, medical students or other personnel not involved in practical surgery may be unsuitable as candidates for assessing the value of a VR training program.

Chirurgisches Training am Simulator

Learning of laparoscopic operative skills is often complex and time consuming resulting in a learning curve especially for novices in surgery. Virtual reality (VR) simulation was developed as an alternative to conventional training, such as active assistance and conventional laparoscopic training with artificially perfused organs (Pop-Trainer). VR simulation enables a wide range of repeatable laparoscopic techniques in variable virtual scenarios. For abdominal surgery four different simulation systems (MIST-VR(R), LapSim, Simsurgery, Lap-Mentor) are currently available and the modules allow simulation of abstract exercises to more advanced laparoscopic procedures, such as laparoscopic sigmoid resection. The effect of VR training on laparoscopic performance and its impact on non-technical skills was evaluated using the simulator LapSim after a constructive validity study. Novices benefited most from VR training and performance in the operating room improved significantly after VR training. Good spatial perception and positive stress coping strategies also enhanced laparoscopic performance. VR simulation provides a tool to shift the laparoscopic learning curve outside the operating room and thus contributes to patient safety. It would be worthwhile to include VR training in the surgical curriculum. For economic reasons regional training centers seem to be an effective way to realize a broad implementation of VR simulation in surgical training. Application and development of VR simulators should be professionally promoted just as flight simulators in aviation.