Torur Dalsgaard

Effect of virtual reality training on laparoscopic surgery: randomised controlled trial

Objective To assess the effect of virtual reality training on an actual laparoscopic operation. Design Prospective randomised controlled and blinded trial. Setting Seven gynaecological departments in the Zeeland region of Denmark. Participants 24 first and second year registrars specialising in gynaecology and obstetrics. Interventions Proficiency based virtual reality simulator training in laparoscopic salpingectomy and standard clinical education (controls). Main outcome measure The main outcome measure was technical performance assessed by two independent observers blinded to trainee and training status using a previously validated general and task specific rating scale. The secondary outcome measure was operation time in minutes. Results The simulator trained group (n=11) reached a median total score of 33 points (interquartile range 32-36 points), equivalent to the experience gained after 20-50 laparoscopic procedures, whereas the control group (n=10) reached a median total score of 23 (22-27) points, equivalent to the experience gained from fewer than five procedures (P<0.001). The median total operation time in the simulator trained group was 12 minutes (interquartile range 10-14 minutes) and in the control group was 24 (20-29) minutes (P<0.001). The observers’ inter-rater agreement was 0.79. Conclusion Skills in laparoscopic surgery can be increased in a clinically relevant manner using proficiency based virtual reality simulator training. The performance level of novices was increased to that of intermediately experienced laparoscopists and operation time was halved. Simulator training should be considered before trainees carry out laparoscopic procedures. Trial registration ClinicalTrials.gov NCT00311792.

Objective assessment of gynecologic laparoscopic skills using the LapSimGyn virtual reality simulator

BackgroundSafe realistic training and unbiased quantitative assessment of technical skills are required for laparoscopy. Virtual reality (VR) simulators may be useful tools for training and assessing basic and advanced surgical skills and procedures. This study aimed to investigate the construct validity of the LapSimGyn VR simulator, and to determine the learning curves of gynecologists with different levels of experience.MethodsFor this study, 32 gynecologic trainees and consultants (juniors or seniors) were allocated into three groups: novices (0 advanced laparoscopic procedures), intermediate level (>20 and <60 procedures), and experts (>100 procedures). All performed 10 sets of simulations consisting of three basic skill tasks and an ectopic pregnancy program. The simulations were carried out on 3 days within a maximum period of 2 weeks. Assessment of skills was based on time, economy of movement, and error parameters measured by the simulator.ResultsThe data showed that expert gynecologists performed significantly and consistently better than intermediate and novice gynecologists. The learning curves differed significantly between the groups, showing that experts start at a higher level and more rapidly reach the plateau of their learning curve than do intermediate and novice groups of surgeons.ConclusionThe LapSimGyn VR simulator package demonstrates construct validity on both the basic skills module and the procedural gynecologic module for ectopic pregnancy. Learning curves can be obtained, but to reach the maximum performance for the more complex tasks, 10 repetitions do not seem sufficient at the given task level and settings. LapSimGyn also seems to be flexible and widely accepted by the users.

VIP and PACAP display different vasodilatory effects in rabbit coronary and cerebral arteries

Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) are closely related peptides with wide distribution in the nervous system. The aim of the present study was to investigate functional characteristics and the influence of sex steroids on the vasodilatory effects of these two peptides in cerebral and coronary vessels from female New Zealand White (NZW) rabbits. The localization and concentration of VIP and PACAP in cardiovascular tissue was evaluated using immunohistochemistry and radioimmunoassays. The vasodilatory effects of VIP and PACAP were investigated using myographs, allowing isometric tension recordings. In order to evaluate the influence of steroid hormones, the rabbits were ovariectomized and randomized to treatment for 4 weeks with 17beta-estradiol (E(2)), Norethindrone Acetate (NETA), E(2)+NETA or placebo. Ring segments of the posterior cerebral artery, the right proximal coronary artery and the distal left coronary artery were examined. The highest concentrations of VIP/PACAP were observed in cerebral and coronary arteries: 5.0/5.7 and 2.8/3.5 pmol/g, respectively. The peptides were localized in nerve fibres innervating the arteries. Both peptides produced dose-dependent vasodilatory responses in all vessels investigated. While the effects of PACAP were identical in cerebral and coronary arterial segments, the effects of VIP displayed significant differences (E(max), pI(2), Hill-slope). Treatment with sex steroids induced no changes in the vascular effects of the two peptides. These results indicate different mechanisms of action for the vasodilating effects of the two closely related peptides VIP and PACAP in different areas of the coronary and cerebrovascular tree. Treatment with female sex steroids does not seem to change these mechanisms.

Reproductive prognosis in endometriosis. A national cohort study

To assess the reproductive long‐term prognosis of women with and without endometriosis, to explore changes over time, and to quantify the contribution of artificial reproductive techniques.

Reproductive prognosis in daughters of women with and without endometriosis

STUDY QUESTION Do daughters of women with endometriosis exhibit an increased risk of endometriosis and impaired long-term reproductive prognosis when compared with daughters of women without endometriosis? SUMMARY ANSWER Daughters of women with endometriosis have over a 2-fold higher risk of endometriosis but no difference in long-term reproductive prognosis compared with controls. WHAT IS KNOWN ALREADY Several studies have found an increased prevalence of endometriosis in sisters and mothers of women with endometriosis, but none have examined the long-term reproductive prognosis in daughters of these patients. STUDY DESIGN, SIZE, DURATION A controlled historical cohort study with a 33-year follow-up. PARTICIPANTS/MATERIALS, SETTING, METHODS Among women 15-49 years old during the period 1977-1982, 24 691 were diagnosed with endometriosis during the study period. These women were age matched to 98 764 women without endometriosis. Daughters of these two groups were followed until 31 December 2009 for an endometriosis diagnosis and reproductive outcomes. Women were excluded from the study at death or if they emigrated. MAIN RESULTS AND THE ROLE OF CHANCE Except for 4-6% of emigrated women, the follow-up rate of the study was almost 100%. Daughters of women with endometriosis (n = 12 389) had a 2.12-fold (95% confidence interval 1.89-2.37, P < 0.0001) increased risk of being diagnosed with endometriosis, compared with daughters of women without endometriosis (n = 52 371). Delivery rate, risk of spontaneous abortions and ectopic pregnancies were similar for the two cohorts, whereas induced abortions were slightly more frequent in the exposed cohort. LIMITATIONS, REASONS FOR CAUTION The most important limitation of the study was the lack of data concerning the attempt to become pregnant. Also, some women with endometriosis might never be diagnosed with the condition. This applies to both the control mothers and the control daughters, but also the daughters of mothers with endometriosis. Other limitations are lack of accounting for potential confounders and the lack of data on preterm birth. However, the influence of most confounding factors was expected to be minimal because of the close matching by age of controls. WIDER IMPLICATIONS OF THE FINDINGS The external validity of the study is expected to be high owing to the unselected inclusion criteria. The encouraging finding was that despite the increased risk of being diagnosed with endometriosis, daughters of women with endometriosis have a reproductive prognosis comparable with that of daughters of women without endometriosis. STUDY FUNDING/COMPETING INTEREST(S) The Department of Gynaecology at Rigshospitalet University Hospital, Copenhagen, covered all expenses of the study. Ø.L. has, within the last 3 years, received honoraria for speeches in pharmacoepidemiological issues and has been expert witness in a legal US case in 2011-2012. None of the other authors have any conflicts of interest.

Robot-assisted surgery in gynecological oncology: Current status and controversies on patient benefits, cost and surgeon conditions- A systematic review.

Robot‐assisted surgery has become more widespread in gynecological oncology. The purpose of this systematic review is to present current knowledge on robot‐assisted surgery, and to clarify and discuss controversies that have arisen alongside the development and deployment.

Validity evidence for procedural competency in virtual reality robotic simulation, establishing a credible pass/fail standard for the vaginal cuff closure procedure

BackgroundThe use of robotic surgery for minimally invasive procedures has increased considerably over the last decade. Robotic surgery has potential advantages compared to laparoscopic surgery but also requires new skills. Using virtual reality (VR) simulation to facilitate the acquisition of these new skills could potentially benefit training of robotic surgical skills and also be a crucial step in developing a robotic surgical training curriculum. The studys objective was to establish validity evidence for a simulation-based test for procedural competency for the vaginal cuff closure procedure that can be used in a future simulation-based, mastery learning training curriculum.MethodsEleven novice gynaecological surgeons without prior robotic experience and 11 experienced gynaecological robotic surgeons (> 30 robotic procedures) were recruited. After familiarization with the VR simulator, participants completed the module ‘Guided Vaginal Cuff Closure’ six times. Validity evidence was investigated for 18 preselected simulator metrics. The internal consistency was assessed using Cronbach’s alpha and a composite score was calculated based on metrics with significant discriminative ability between the two groups. Finally, a pass/fail standard was established using the contrasting groups’ method.ResultsThe experienced surgeons significantly outperformed the novice surgeons on 6 of the 18 metrics. The internal consistency was 0.58 (Cronbach’s alpha). The experienced surgeons’ mean composite score for all six repetitions were significantly better than the novice surgeons’ (76.1 vs. 63.0, respectively, p < 0.001). A pass/fail standard of 75/100 was established. Four novice surgeons passed this standard (false positives) and three experienced surgeons failed (false negatives).ConclusionOur study has gathered validity evidence for a simulation-based test for procedural robotic surgical competency in the vaginal cuff closure procedure and established a credible pass/fail standard for future proficiency-based training.

Examining validity evidence for a simulation-based assessment tool for basic robotic surgical skills

Increasing focus on patient safety makes it important to ensure surgical competency among surgeons before operating on patients. The objective was to gather validity evidence for a virtual-reality simulator test for robotic surgical skills and evaluate its potential as a training tool. Surgeons with varying experience in robotic surgery were recruited: novices (zero procedures), intermediates (1–50), experienced (> 50). Five experienced surgeons rated five exercises on the da Vinci Skills Simulator. Participants were tested using the five exercises. Participants were invited back 3 times and completed a total of 10 attempts per exercise. The outcome was the average simulator performance score for the 5 exercises. 32 participants from 5 surgical specialties were included. 38 participants completed all 4 sessions. A moderate correlation between the average total score and robotic experience was identified for the first attempt (Spearman r = 0.58; p = 0.0004). A difference in average total score was observed between novices and intermediates [median score 61% (IQR 52–66) vs. 83% (IQR 75–91), adjusted p < 0.0001], as well as novices and experienced [median score 61% (IQR 52–66) vs. 80 (IQR 69–85), adjusted p = 0.002]. All three groups improved their performance between the 1st and 10th attempts (p < 0.00). This study describes validity evidence for a virtual-reality simulator for basic robotic surgical skills, which can be used for assessment of basic competency and as a training tool. However, more validity evidence is needed before it can be used for certification or high-stakes assessment.

Long-term estradiol treatment improves VIP-mediated vasodilation in atherosclerotic proximal coronary arteries

The aim of the present study was to evaluate the impact of long-term estrogen replacement therapy (ERT) on the vasodilatory effect of the two peptides vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) in atherosclerotic coronary and cerebral arteries. Female ovariectomized homozygous Watanabe heritable hyperlipidemic rabbits were randomized to 16 weeks treatment with 17beta-estradiol or placebo. The diet was semisynthetic, thereby avoiding the influence of phytoestrogens. Artery ring segments were mounted for isometric tension recordings in myographs. Following precontraction, the dose-response relationships for VIP and PACAP were evaluated.Treatment with 17beta-estradiol significantly improved the maximum VIP-mediated vasodilation (E(max), percentage of precontraction) in proximal coronary arteries (45.8+/-9.6% vs. 24.1+/-3.7%, p<0.05). In the same artery segment, 17beta-estradiol induced a significant decrease in the relative ratio between the repeated contractile response to potassium 30 and 120 mM (100+/-7% vs. 132+/-11%, p<0.05). For distal coronary arteries, there was a tendency to similar changes, but no statistical differences for the potassium or VIP responses in cerebral or distal coronary arteries were found between the two groups. 17beta-estradiol induced no changes in the PACAP-mediated vasodilation. These results suggest that long-term treatment with 17beta-estradiol improves the VIP-mediated but not the PACAP-mediated vasodilation in atherosclerotic proximal coronary arteries.