Christian Rifbjerg Larsen

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.

The efficacy of virtual reality simulation training in laparoscopy: a systematic review of randomized trials

Background. Virtual reality (VR) simulators for surgical training might possess the properties needed for basic training in laparoscopy. Evidence for training efficacy of VR has been investigated by research of varying quality over the past decade. Objective. To review randomized controlled trials regarding VR training efficacy compared with traditional or no training, with outcome measured as surgical performance in humans or animals. Data sources. In June 2011 Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science and Google Scholar were searched using the following medical subject headings (MeSh) terms: Laparoscopy/standards, Computing methodologies, Programmed instruction, Surgical procedures, Operative, and the following free text terms: Virtual real* OR simulat* AND Laparoscop* OR train* Limits: Controlled trials. Study eligibility criteria. All randomized controlled trials investigating the effect of VR training in laparoscopy, with outcome measured as surgical performance. Methods. A total of 98 studies were screened, 26 selected and 12 included, with a total of 241 participants. Results. Operation time was reduced by 17–50% by VR training, depending on simulator type and training principles. Proficiency‐based training appeared superior to training based on fixed time or fixed numbers of repetition. Simulators offering training for complete operative procedures came out as more efficient than simulators offering only basic skills training. Conclusions. Skills in laparoscopic surgery can be increased by proficiency‐based procedural VR simulator training. There is substantial evidence (grade IA – IIB) to support the use of VR simulators in laparoscopic training.

Objective assessment of surgical competence in gynaecological laparoscopy: development and validation of a procedure‐specific rating scale

Objective  The purpose of this study was to develop a global‐ and a procedure‐specific rating scale based on a well‐validated generic model (objective structured assessment of technical skills) for assessment of technical skills in laparoscopic gynaecology. Furthermore, we aimed to investigate the construct validity and the interrater agreement (IRA) of the rating scale. We investigated both the gamma coefficient (Kendall’s rank correlation), which is a measure of the strength of dependence between observations, and the kappa value for each of the ten individual items included in the rating scale.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized trial.

Objective:To investigate the impact of instructor feedback versus no instructor feedback when training a complex operational task on a laparoscopic virtual reality simulator. Background:Simulators are now widely accepted as a training tool, but there is insufficient knowledge about how much feedback is necessary, which is useful for sustainable implementation. Methods:A randomized trial complying with CONSORT Statement. All participants had to reach a predefined proficiency level for a complex operational task on a virtual reality simulator. The intervention group received standardized instructor feedback a maximum of 3 times. The control group did not receive instructor feedback. Participants were senior medical students without prior laparoscopic experience (n = 99). Outcome measures were time, repetitions, and performance score to reach a predefined proficiency level. Furthermore, influence of sex and perception of own surgical skills were examined. Results:Time (in minutes) and repetitions were reduced in the intervention group (162 vs 342 minutes; P < 0.005) and (29 vs 65 repetitions; P < 0.005). The control group achieved a higher performance score than the intervention group (57% vs 49%; P = 0.004). Men used less time (in minutes) than women (P = 0.037), but no sex difference was observed for repetitions (P = 0.20). Participants in the intervention group had higher self-perception regarding surgical skills after the trial (P = 0.011). Conclusions:Instructor feedback increases the efficiency when training a complex operational task on a virtual reality simulator; time and repetitions used to achieve a predefined proficiency level were significantly reduced in the group that received instructor feedback compared with the control group. Trial registration number: NCT01497782.

Integration of laparoscopic virtual‐reality simulation into gynaecology training

Please cite this paper as: Burden C, Oestergaard J, Larsen C. Integration of laparoscopic virtual‐reality simulation into gynaecology training. BJOG 2011;118 (Suppl. 3): 5–10.

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.

A structured four‐step curriculum in basic laparoscopy: development and validation

The objective of this study was to develop a four‐step curriculum in basic laparoscopy consisting of validated modules integrating a cognitive component, a practical component and a procedural component.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized educational trial

BackgroundSeveral studies have found a positive effect on the learning curve as well as the improvement of basic psychomotor skills in the operating room after virtual reality training. Despite this, the majority of surgical and gynecological departments encounter hurdles when implementing this form of training. This is mainly due to lack of knowledge concerning the time and human resources needed to train novice surgeons to an adequate level. The purpose of this trial is to investigate the impact of instructor feedback regarding time, repetitions and self-perception when training complex operational tasks on a virtual reality simulator.Methods/DesignThe study population consists of medical students on their 4th to 6th year without prior laparoscopic experience. The study is conducted in a skills laboratory at a centralized university hospital. Based on a sample size estimation 98 participants will be randomized to an intervention group or a control group. Both groups have to achieve a predefined proficiency level when conducting a laparoscopic salpingectomy using a surgical virtual reality simulator. The intervention group receives standardized instructor feedback of 10 to 12 min a maximum of three times. The control group receives no instructor feedback. Both groups receive the automated feedback generated by the virtual reality simulator. The study follows the CONSORT Statement for randomized trials. Main outcome measures are time and repetitions to reach the predefined proficiency level on the simulator. We include focus on potential sex differences, computer gaming experience and self-perception.DiscussionThe findings will contribute to a better understanding of optimal training methods in surgical education.Trial RegistrationNCT01497782

Effect of Instructor Feedback on Skills Retention After Laparoscopic Simulator Training: Follow-Up of a Randomized Trial

BACKGROUND Instructor feedback reduces the number of repetitions and time to reach proficiency during laparoscopic simulator training. The objective of this study was to examine the effect of instructor feedback on long-term skill retention. METHODS A 6-month follow-up of a randomized trial. Participants were surgical novices (medical students). All participants (n = 99) initially practiced a laparoscopic salpingectomy on the LapSim virtual reality simulator to proficiency. The intervention group could request instructor feedback, whereas the control group could not. After 6 months, the participants (n = 65) practiced on the simulator until they reached proficiency again. The primary outcomes were the total time and the number of repetitions. RESULTS Initially, the intervention group used significantly fewer repetitions (29 vs 65, p < 0.0005) and less total training time (162 vs 342 min, p < 0.0005) than the control group to reach the proficiency level. At follow-up, both the groups used an equal number of repetitions (21 vs 20, p = 0.72) and time (83 vs 73 min, p = 0.37) to reach the same proficiency level. CONCLUSIONS Instructor feedback during proficiency-based laparoscopic simulator training does not affect the long-term retention of skills.