Validation of a Novel Virtual Reality Simulator for Robotic Surgery

Objective. With the increase in robotic-assisted laparoscopic surgery there is a concomitant rising demand for training methods. The objective was to establish face and construct validity of a novel virtual reality simulator (dV-Trainer, Mimic Technologies, Seattle, WA) for the use in training of robot-assisted surgery. Methods. A comparative cohort study was performed. Participants (n=42) were divided into three groups according to their robotic experience. To determine construct validity, participants performed three different exercises twice. Performance parameters were measured. To determine face validity, participants filled in a questionnaire after completion of the exercises. Results. Experts outperformed novices in most of the measured parameters. The most discriminative parameters were “time to complete” and “economy of motion” (P<0.001). The training capacity of the simulator was rated 4.6 ± 0.5 SD on a 5-point Likert scale. The realism of the simulator in general, visual graphics, movements of instruments, interaction with objects, and the depth perception were all rated as being realistic. The simulator is considered to be a very useful training tool for residents and medical specialist starting with robotic surgery. Conclusions. Face and construct validity for the dV-Trainer could be established. The virtual reality simulator is a useful tool for training robotic surgery

Increasing experience in laparoscopic staging of early ovarian cancer

We assessed the effect of increasing experience of a single surgeon (learning curve) in the laparoscopic staging procedure for women with early ovarian cancer and compared the results with the literature. We retrospectively analysed a total of 25 women with apparent early-stage ovarian cancer who underwent a laparoscopic staging procedure by the same surgeon. Three time periods, based on date of surgery, were compared with respect to operating time, amount of lymph nodes harvested and surgical outcome. There was no significant difference in operation time, estimated blood loss and hospital stay between the three periods. There was, however, a significant increase in the median number of pelvic and para-aortal lymph nodes harvested (group1 = 6.5, group 2 = 8.0 and group 3 = 21.0; P < 0.005). For the total period, median operation time was 235 min and median estimated blood loss was 100 ml. The median length of hospital stay was 4.0 days. Two intraoperative and two postoperative complications occurred. The upstaging rate was 32%. The mean interval between initial surgery and laparoscopic staging was 51.2 days. Mean duration of follow-up was 43 months, range (1–116 months). Five (20%) patients had recurrences, and two (8%) patients died of the disease. In conclusion, there is a significant learning curve for the laparoscopic full staging procedure in ovarian cancer. In our study this is mainly reflected in the amount of lymph nodes harvested and not in the total operating time

Apixaban versus no anticoagulation after anticoagulation-associated intracerebral haemorrhage in patients with atrial fibrillation in the Netherlands (APACHE-AF):a randomised, open-label, phase 2 trial

Background In patients with atrial fibrillation who survive an anticoagulation-associated intracerebral haemorrhage, a decision must be made as to whether restarting or permanently avoiding anticoagulation is the best long-term strategy to prevent recurrent stroke and other vascular events. In APACHE-AF, we aimed to estimate the rates of non-fatal stroke or vascular death in such patients when treated with apixaban compared with when anticoagulation was avoided, to inform the design of a larger trial. Methods APACHE-AF was a prospective, randomised, open-label, phase 2 trial with masked endpoint assessment, done at 16 hospitals in the Netherlands. Patients who survived intracerebral haemorrhage while treated with anticoagulation for atrial fibrillation were eligible for inclusion 7-90 days after the haemorrhage. Participants also had a CHA2DS2-VASc score of at least 2 and a score on the modified Rankin scale (mRS) of 4 or less. Participants were randomly assigned (1:1) to receive oral apixaban (5 mg twice daily or a reduced dose of 2.5 mg twice daily) or to avoid anticoagulation (oral antiplatelet agents could be prescribed at the discretion of the treating physician) by a central computerised randomisation system, stratified by the intention to start or withhold antiplatelet therapy in participants randomised to avoiding anticoagulation, and minimised for age and intracerebral haemorrhage location. The primary outcome was a composite of non-fatal stroke or vascular death, whichever came first, during a minimum follow-up of 6 months, analysed using Cox proportional hazards modelling in the intention-to-treat population. APACHE-AF is registered with ClinicalTrials.gov (NCT02565693) and the Netherlands Trial Register (NL4395), and the trial is closed to enrolment at all participating sites. Findings Between Jan 15, 2015, and July 6, 2020, we recruited 101 patients (median age 78 years [IQR 73-83]; 55 [54%] were men and 46 [46%] were women; 100 [99%] were White and one [1%] was Black) a median of 46 days (IQR 21-74) after intracerebral haemorrhage. 50 were assigned to apixaban and 51 to avoid anticoagulation (of whom 26 [51%] started antiplatelet therapy). None were lost to follow-up. Over a median follow-up of 1.9 years (IQR 1.0-3.1; 222 person-years), non-fatal stroke or vascular death occurred in 13 (26%) participants allocated to apixaban (annual event rate 12.6% [95% CI 6.7-21.5]) and in 12 (24%) allocated to avoid anticoagulation (11.9% [95% CI 6.2-20.8]; adjusted hazard ratio 1.05 [95% CI 0.48-2.31]; p=0.90). Serious adverse events that were not outcome events occurred in 29 (58%) of 50 participants assigned to apixaban and 29 (57%) of 51 assigned to avoid anticoagulation. Interpretation Patients with atrial fibrillation who had an intracerebral haemorrhage while taking anticoagulants have a high subsequent annual risk of non-fatal stroke or vascular death, whether allocated to apixaban or to avoid anticoagulation. Our data underline the need for randomised controlled trials large enough to allow identification of subgroups in whom restarting anticoagulation might be either beneficial or hazardous. Copyright (C) 2021 Elsevier Ltd. All rights reserved

Two-year clinical follow-up of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN): Design and statistical analysis plan of the extended follow-up study

Background: MR CLEAN was the first randomized trial to demonstrate the short-term clinical effectiveness of endovascular treatment in patients with acute ischemic stroke caused by large vessel occlusion in the anterior circulation. Several other trials confirmed that endovascular treatment improves clinical outcome at three months. However, limited data are available on long-term clinical outcome. We aimed to estimate the effect of endovascular treatment on functional outcome at two-year follow-up in patients with acute ischemic stroke. Secondly, we aimed to assess the effect of endovascular treatment on major vascular events and mortality during two years of follow-up. Methods: MR CLEAN is a multicenter clinical trial with randomized treatment allocation, open-label treatment, and blinded endpoint evaluation. Patients included were 18 years or older with acute ischemic stroke caused by a proven anterior proximal artery occlusion who could be treated within six hours after stroke onset. The intervention contrast was endovascular treatment and usual care versus no endovascular treatment and usual care. The current study extended the follow-up duration from three months to two years. The primary outcome is the score on the modified Rankin scale at two years. Secondary outcomes include all-cause mortality and the occurrence of major vascular events within two years of follow-up. Discussion: The results of our study provide information on the long-term clinical effectiveness of endovascular treatment, which may have implications for individual treatment decisions and estimates of cost-effectiveness. Trial registration:NTR1804. Registered on 7 May 2009; ISRCTN10888758. Registered on 24 July 2012 (main MR CLEAN trial); NTR5073. Registered on 26 February 2015 (extended follow-up study)

A multicenter prospective cohort study on camera navigation training for key user groups in minimally invasive surgery

Untrained laparoscopic camera assistants in minimally invasive surgery (MIS) may cause suboptimal view of the operating field, thereby increasing risk for errors. Camera navigation is often performed by the least experienced member of the operating team, such as inexperienced surgical residents, operating room nurses, and medical students. The operating room nurses and medical students are currently not included as key user groups in structured laparoscopic training programs. A new virtual reality laparoscopic camera navigation (LCN) module was specifically developed for these key user groups. This multicenter prospective cohort study assesses face validity and construct validity of the LCN module on the Simendo virtual reality simulator. Face validity was assessed through a questionnaire on resemblance to reality and perceived usability of the instrument among experts and trainees. Construct validity was assessed by comparing scores of groups with different levels of experience on outcome parameters of speed and movement proficiency. The results obtained show uniform and positive evaluation of the LCN module among expert users and trainees, signifying face validity. Experts and intermediate experience groups performed significantly better in task time and camera stability during three repetitions, compared to the less experienced user groups (P < .007). Comparison of learning curves showed significant improvement of proficiency in time and camera stability for all groups during three repetitions (P < .007). The results of this study show face validity and construct validity of the LCN module. The module is suitable for use in training curricula for operating room nurses and novice surgical trainees, aimed at improving team performance in minimally invasive surger

Twelve-year retrospective review of unintended pregnancies after Essure sterilization in the Netherlands

Objective To identify factors contributing to the occurrence of unintended pregnancies after Essure sterilization in the Netherlands. Even though Essure is a permanent method of contraception, unintended pregnancies have been reported.  Design  Retrospective case series analysis. Setting Not applicable. Patient(s) Thirty-five pregnancies were reported in the Netherlands after Essure sterilization from 2002 through 2014 out of 27,346 placements. Intervention(s) Data regarding Essure placement procedure, confirmation tests, and pregnancy outcome of the reported cases were obtained and analyzed to identify a possible cause of failure. Main Outcome Measure(s) Four causes of failure were identified: perforation (n = 10), expulsion (n = 7), unilateral placement (n = 7), and luteal pregnancy (n = 2).  Result(s) The occurrence of most pregnancies was related to physician noncompliance (n = 14). The other cases were associated with patient noncompliance (n = 5) or misinterpretation of the confirmation test (n = 9). Most pregnancies occurred within the first 24 months after the 3-month confirmation test (n = 23). Conclusion(s) The results of this study show that the incidence of pregnancies after Essure sterilization is low. Most pregnancies were related to incorrect positioning of a device or unilateral placement, and seem therefore preventable. Unilateral placement without prior history of salpingectomy should always be considered as unsuccessful sterilization. Furthermore, interpretation of the confirmation tests should be done by trained physicians, and with caution. We want to emphasize the importance of strictly adhering to placement and follow-up protocols

Haptic Feedback, Force Feedback, and Force-Sensing in Simulation Training for Laparoscopy : A Systematic Overview

OBJECTIVES: To provide a systematic overview of the literature assessing the value of haptic and force feedback in current simulators teaching laparoscopic surgical skills. DATA SOURCES: The databases of Pubmed, Cochrane, Embase, Web of Science, and Google Scholar were searched to retrieve relevant studies published until January 31st, 2017. The search included laparoscopic surgery, simulation, and haptic or force feedback and all relevant synonyms. METHODS: Duplicates were removed, and titles and abstracts screened. The remaining articles were subsequently screened full text and included in this review if they followed the inclusion criteria. A total of 2 types of feedback have been analyzed and will be discussed separately: haptic- and force feedback. RESULTS: A total of 4023 articles were found, of which 87 could be used in this review. A descriptive analysis of the data is provided. Results of the added value of haptic interface devices in virtual reality are variable. Haptic feedback is most important for more complex tasks. The interface devices do not require the highest level of fidelity. Haptic feedback leads to a shorter learning curve with a steadier upward trend. Concerning force feedback, force parameters are measured through force sensing systems in the instrument and/or the environment. These parameters, especially in combination with motion parameters, provide box trainers with an objective evaluation of laparoscopic skills. Feedback of force-use both real time and postpractice has been shown to improve training. CONCLUSIONS: Haptic feedback is added to virtual reality simulators to increase the fidelity and thereby improve training effect. Variable results have been found from adding haptic feedback. It is most important for more complex tasks, but results in only minor improvements for novice surgeons. Force parameters and force feedback in box trainers have been shown to improve training results

Implementation of simulation in surgical practice: Minimally invasive surgery has taken the lead: The Dutch experience

Minimal invasive techniques are rapidly becoming standard surgical techniques for many surgical procedures. To develop the skills necessary to apply these techniques, box trainers and/or inanimate models may be used, but these trainers lack the possibility of inherent objective classification of results. In the past decade, virtual reality (VR) trainers were introduced for training minimal invasive techniques. Minimally invasive surgery (MIS) is, by nature, very suitable for this type of training. The specific psychomotor skills and eye--hand coordination needed for MIS can be mastered largely using VR simulation techniques. It is also possible to transfer skills learned on a simulator to real operations, resulting in error reduction and shortening of procedural operating time. The authors aim to enlighten the process of gaining acceptance in the Netherlands for novel training techniques. The Dutch Societies of Surgery, Obstetrics and Gynecology, and Urology each developed individual training curricula for MIS using simulation techniques, to be implemented in daily practice. The ultimate goal is to improve patient safety. The authors outline the opinions of actors involved, such as different simulators, surgical trainees, surgeons, surgical societies, hospital boards, government, and the public. The actual implementation of nationwide training curricula for MIS is, however, a challenging step

Face and construct validity of virtual reality simulation of laparoscopic gynecologic surgery

OBJECTIVE: The objective of the study was to validate virtual reality simulation in assessing laparoscopic skills in gynecology by establishing the extent of realism of the simulation to the actual task (face validity) and the degree to which the results of the test one uses reflects the subject tested (construct validity). STUDY DESIGN: Subjects (n = 56) were divided into 3 groups: novices (n = 15), intermediates (n = 20), and experts (n = 21). Participants completed 3 repetitions of a training program consisting of 4 basic skills and 3 gynecologic procedural simulations. The performance was compared between groups using a post hoc Student t test with the Bonferroni technique. Face validity was determined by using a questionnaire of 27 statements. RESULTS: Resulting from the questionnaire, the opinion about the realism and training capacities of the tasks was favorable among all groups. The degree of prior laparoscopic experience was reflected in the outcome performance parameters of the tasks. Experts achieved significant better scores on specific parameters. CONCLUSION: The results of this study indicate acceptance and thus face validity of the system among both reference (novice, intermediate) and expert group. There is a significant difference between subjects with different laparoscopic experience and thereby construct validity for the laparoscopic simulator could be establishe