Impact of simulated three-dimensional perception on precision of depth judgements, technical performance and perceived workload in laparoscopy

Low-Cost, High-Fidelity Skin and Intestine Surrogates for Surgical Training

INTRODUCTION

Organ surrogates play a pivotal role in training surgical residents, offering a safe and cost-effective alternative to live human patients or animals. However, existing surrogates often fall short, either due to their high cost or inability to accurately replicate the mechanical behavior and anatomical complexity of human tissue. This study aims to address these limitations by developing affordable, realistic, and biomechanically accurate organ surrogates tailored for surgical training.

MATERIALS AND METHODS

Our methods involve 3D printing customized molds for pour casting, injection molding, and rotational molding, employing off-the-shelf platinum-cure silicone rubbers and specially formulated silicone-based blends as base materials. This approach ensures cost-effectiveness and allows utilizing commercially available materials and accessible laboratory equipment, enabling low-cost in-house fabrication of multi-layered skin and intestine surrogates for surgical training.

RESULTS

Feedback received from surgical residents and surgeons at the University of Missouri School of Medicine indicates that our surrogates consistently outperform industry-standard models in terms of biomechanical accuracy. Moreover, our cost analysis revealed that our fabrication methods yield surrogates that are over 90% less expensive than commercial alternatives.

CONCLUSIONS

The skin and intestine surrogates developed in this study demonstrate the feasibility of creating affordable, high-fidelity surgical training models using accessible materials and established fabrication techniques. By addressing the limitations of existing surrogates, this work lays the foundation for developing a broader range of anatomical models. These advances have the potential to improve the effectiveness and accessibility of surgical training.

Transferability of laparoscopic skills acquired from three-dimensional high-definition and ultra-high definition endovision system to two-dimensional high-definition endovision system: an ex-vivo randomized study

Three-dimensional high-definition (3D HD) and ultra-high-definition (4 K HD) endovision systems are rapidly adopted in academic setting. However, transferability of laparoscopic skills acquired from these systems to two-dimensional high-definition (2D HD) endovision system is not known. Forty stereo-enabled surgical residents were randomized into two groups. They performed three standardized surgical tasks, Task 1(Peg transfer), Task 2(Precision touch on uneven surface) and Task 3(Surgical knotting on rubber tube) for 15 repetitions using either 3D HD or 4 K HD. Both groups then performed the same tasks using 2D HD for 5 repetitions. Their performances were evaluated for execution time (speed) and error scores (safety). The residents in 3D HD group performed all three tasks significantly faster than residents in 4 K HD group with comparable error scores. The time taken to complete the tasks on 2D HD were comparable between residents trained in 3D HD and 4 K HD in two out of three tasks (p = 0.027, P = 0.115, p = 0.368 in task 1, 2 and 3 respectively). However, in two out of three tasks, residents trained on 3D HD committed significantly more errors than residents trained on 4 K HD (p < 0.0001, p < 0.001 in task 1 and task 2 respectively). Skill acquired on 4 K HD seems transferable to 2D HD environment. Participants trained in 3D HD made more errors while performing the tasks in 2D HD. It may be prudent to offer additional training on 2D HD to residents trained on 3D HD for safer laparoscopic surgical practice.

Navigating the Future of 3D Laparoscopic Liver Surgeries: Visualization of Internal Anatomy on Laparoscopic Images With Augmented Reality

INTRODUCTION

Liver tumor resection requires precise localization of tumors and blood vessels. Despite advancements in 3-dimensional (3D) visualization for laparoscopic surgeries, challenges persist. We developed and evaluated an augmented reality (AR) system that overlays preoperative 3D models onto laparoscopic images, offering crucial support for 3D visualization during laparoscopic liver surgeries.

METHODS

Anatomic liver structures from preoperative computed tomography scans were segmented using open-source software including 3D Slicer and Maya 2022 for 3D model editing. A registration system was created with 3D visualization software utilizing a stereo registration input system to overlay the virtual liver onto laparoscopic images during surgical procedures. A controller was customized using a modified keyboard to facilitate manual alignment of the virtual liver with the laparoscopic image. The AR system was evaluated by 3 experienced surgeons who performed manual registration for a total of 27 images from 7 clinical cases. The evaluation criteria included registration time; measured in minutes, and accuracy; measured using the Dice similarity coefficient.

RESULTS

The overall mean registration time was 2.4±1.7 minutes (range: 0.3 to 9.5 min), and the overall mean registration accuracy was 93.8%±4.9% (range: 80.9% to 99.7%).

CONCLUSION

Our validated AR system has the potential to effectively enable the prediction of internal hepatic anatomic structures during 3D laparoscopic liver resection, and may enhance 3D visualization for select laparoscopic liver surgeries.

Association between stereoacuity and simulated clinical performance among dental students: an exploratory investigation

INTRODUCTION

Dentistry is a profession that requires a high level of the hand-eye coordination. Although considerable attention has been put on dental students' manual dexterity, little emphasis was made on students' visual competency as a variable influencing their competency. In this study, we aimed to assess the association between dental students' stereopsis and their pre-clinical performance.

METHODS

Dental students (n = 49) were required to perform the porcelain-fused-to-crown preparation for a lower first molar and an upper central incisor plastic teeth mounted on phantom heads. Performance was assessed by two faculty members based on two rubrics, which collectively included 11 assessment criteria. Afterward, students undertook a stereoacuity test using Randot stereotest. Stereopsis values greater than 40 arc/s were considered abnormal.

RESULTS

A significant negative correlation was seen between stereopsis scores and students' grades for the upper incisor (p < 0.01), but not for the lower molar. An association was also seen between abnormal stereopsis and students' poor performance in preparing the finish line of the incisor tooth (p = 0.024).

CONCLUSION

Abnormal stereopsis can impact dental students' performance, particularly when preparing teeth indirectly using a dental mirror. Dental educators should give attention to students' stereoacuity, in a manner similar to that given to students' manual dexterity.

Usefulness of three-dimensional imaging in a flexible endoscopic surgery platform with multi-degrees-of-freedom articulating devices

BACKGROUND AND AIMS

Recent studies on endoscopic submucosal dissection have aimed to reduce the difficulty of the procedure by using multi-degrees-of-freedom articulating devices. In this study, we evaluated the usefulness of adding three-dimensional (3D) video imaging into simulated endoscopic submucosal dissection tasks using multi-degrees-of-freedom devices.

METHODS

We designed an endoscopic platform with a 3D camera and two multi-degrees-of-freedom devices. Four ex vivo bench tasks were created, and a crossover study comparing 2D and 3D conditions was conducted on 15 volunteers. In each task, performance such as procedure time and accuracy were objectively evaluated. Additionally, a comprehensive visual analogue scale questionnaire was conducted.

RESULTS

In the tasks simulating submucosal flap grasping, marking, and full-area incision, the use of 3D imaging significantly improved the speed and accuracy of the multi-degrees-of-freedom device manipulation (p < .01). No significant differences were observed in the task that simulated the dissection procedure. Furthermore, it appears that the accuracy of recognizing curved surfaces may be reduced in the 3D environment. Operators reported subjective increases in recognizability and operability with the 3D camera, along with an increase in asthenopia (p < .01).

CONCLUSIONS

3D vision improves the technical accuracy of certain simulated multi-degrees-of-freedom endoscopic submucosal dissection tasks and subjectively improved operating conditions, at the cost of increased eye strain.

A Digital Alternative to the TNO Stereo Test to Qualify Military Aircrew

INTRODUCTION: Stereopsis is usually required in military aviators and may become increasingly important with reliance on newer technologies such as binocular Helmet-Mounted Displays (HMDs) and stereo displays. The current stereo test used to qualify UK military aircrew (TNO test) has many limitations. To address these limitations, two computer-based digital versions of a random dot stereogram (RDS) were developed: a static version (dRDS-S), and a version in which the dots appear to move dynamically within the depth plane (dRDS-D), both capable of measuring stereo acuity to threshold.METHODS: There were 41 participants who performed all 3 stereo tests, TNO and both digital dRDS tests, on two separate occasions.RESULTS: The best (lowest) mean stereo acuity threshold was measured with dRDS-S (33.79 arcseconds, range 12.64-173) and the worst mean stereo acuity thresholds were measured with the TNO test (91 arcseconds, range 60-240). Both dRDS tests were strongly correlated, but neither correlated with the TNO test. Both dRDS tests were more reliable, as indicated with tighter limits of agreement.DISCUSSION: With a large floor effect at 60 arcseconds, the TNO test was unable to characterize any finer degree of stereo acuity. Both dRDS tests demonstrated better test-retest reliability and addressed many of the limitations seen with the TNO test. The dRDS tests were not correlated with the TNO test, which suggests that the TNO test does not provide the accuracy or reliability for use as a meaningful aeromedical screening test. The dRDS tests will enable research to investigate the relationship between stereo acuity and operational performance.Posselt BN, Seemiller E, Winterbottom M, Baber C, Hadley S. A digital alternative to the TNO stereo test to qualify military aircrew. Aerosp Med Hum Perform. 2022; 93(12):846-854.

Video Learning of Surgical Procedures: A Randomized Comparison of Microscopic, 2- and 3-Dimensional Endoscopic Ear Surgery Techniques

BACKGROUND

Video learning of surgical procedures helps trainees gain an initial understanding of the complex anatomy and the surgical procedure. Because no comparative studies have yet examined which microsurgical approach to the middle ear is most suitable for video learning, the authors investigated objective and subjective outcomes for medical trainees observing microscopic, 2-dimensional (2D) endoscopic, and 3- dimensional (3D) endoscopic ear surgeries.

METHODS

Sixty-two medical students (min. 3rd year) from the University Hospital of Bern watched three standardized videos of a type I tympanoplasty surgery recording, conducted with a microscope, a 2D endoscope, and a 3D endoscope, respectively. The authors measured participants' learning outcome, eye movements, cognitive load, and subjective preferences.

RESULTS

Of the 62 participants included in the study, 14 were male (22.58%), and mean age was 24.44 years (range: 21-29). Learning outcome was highest after watching the 3D endoscopic video (mean [SD], 59.48% [20.57%]). Differences in score were statistically significant: 2D endoscopic video (mean difference: -6.56%, 95% CI: -13.02 to -0.10%), microscopic video (mean difference: -13.82%, 95% CI: -20.27 to -7.36%). Participants showed lowest average eye fixation duration when watching the 3D endoscopic video (mean [SD], 307 ms [109 ms]), with statistically significant differences to the 2D endoscopic video (mean difference: -139 ms, 95% CI: -185 to -93 ms), and the microscopic video (mean difference: -264 ms, 95% CI: -310 to -218 ms). Participants reported lowest cognitive load for the 2D and 3D endoscopic videos. Ratings on discomfort, usability, naturalness, depth perception, and image quality were in favor of the 3D endoscopic video.

CONCLUSION

The 3D endoscopic technique offers many advantages for video learning in terms of knowledge gain, visual field exploration, and subjective evaluation. To optimize learning effects in trainees, the authors recommend the use of endoscopes in middle ear surgery and, if available, using 3D technology.

The safety and feasibility of endoscopic submucosal dissection using a flexible three-dimensional endoscope for early gastric cancer and superficial esophageal cancer: A prospective observational study

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is performed as one of standard treatments for patients with early gastric cancer (EGC) and superficial esophageal squamous cancer (SESCC). A prototype of a flexible endoscope with a 3-D system has been recently developed. This study aimed to investigate the safety and feasibility of ESD using a 3-D flexible endoscope (3-D ESD) for EGC and SESCC.

METHODS

This single-center, prospective, observational study enrolled patients who underwent planned 3-D ESD. The clinical outcomes, including the incidence of adverse events and treatment results, were analyzed. Visibility and manipulation during 3-D ESD were evaluated using a visual analog scale (VAS). We also evaluated the effect of the 3-D system on the endoscopist using VAS and the critical flicker fusion frequency (CFFF).

RESULTS

We analyzed 47 EGC and 20 SESCC cases. There are no bleeding cases that required transfusion and perforation during 3-D ESD in both EGC and SESCC patients. However, the incidence of delayed bleeding and delayed perforation was 1.5% (one case) each. The mean VAS scores for recognizing the submucosal layer during the submucosal dissection, visual perception of blood vessel, and depth perception were 72.7 ± 22.2, 74.7 ± 21.8, and 78.2 ± 19.9, respectively. In contrast, the mean VAS score for manipulation was 25.4 ± 19.7. Among endoscopists, there was no significant difference in the VAS of eyestrain and headache before and after ESD, and there was no significant difference in the CFFF.

CONCLUSION

The safety and feasibility of 3-D ESD for EGC and SESCC are acceptable in both patients and endoscopists.

Associations Between Binocular Depth Perception and Performance Gains in Laparoscopic Skill Acquisition

The ability to perceive differences in depth is important in many daily life situations. It is also of relevance in laparoscopic surgical procedures that require the extrapolation of three-dimensional visual information from two-dimensional planar images. Besides visual-motor coordination, laparoscopic skills and binocular depth perception are demanding visual tasks for which learning is important. This study explored potential relations between binocular depth perception and individual variations in performance gains during laparoscopic skill acquisition in medical students naïve of such procedures. Individual differences in perceptual learning of binocular depth discrimination when performing a random dot stereogram (RDS) task were measured as variations in the slope changes of the logistic disparity psychometric curves from the first to the last blocks of the experiment. The results showed that not only did the individuals differ in their depth discrimination; the extent with which this performance changed across blocks also differed substantially between individuals. Of note, individual differences in perceptual learning of depth discrimination are associated with performance gains from laparoscopic skill training, both with respect to movement speed and an efficiency score that considered both speed and precision. These results indicate that learning-related benefits for enhancing demanding visual processes are, in part, shared between these two tasks. Future studies that include a broader selection of task-varying monocular and binocular cues as well as visual-motor coordination are needed to further investigate potential mechanistic relations between depth perceptual learning and laparoscopic skill acquisition. A deeper understanding of these mechanisms would be important for applied research that aims at designing behavioral interventions for enhancing technology-assisted laparoscopic skills.

Years of experience is more effective in defining experts in the gaze analysis of laparoscopic suturing task than task duration

In this study, the relationship between gaze patterns, task duration, and years of experience, which are commonly used to define and evaluate expert surgeons in laparoscopic surgery, was identified. Ten surgeons with 1-28 years of experience and six inexperienced students were included. Subjects used forceps to repeat the task of suturing a suture pad. Each subject wore an eye-marking recorder, and gaze points were recorded and analyzed. No significant relationship between task duration and gaze pattern was observed. However, there was a significant relationship between a surgeon's years of experience and the percentage of time spent gazing at the forceps. Subjects with more years of experience operated without looking at the forceps and fixed their gaze on the operational target. Therefore, when analyzing laparoscopic gazing patterns, it may be more appropriate to define an "expert" based on the years of experience rather than task duration.

Aptitude and attitude: predictors of performance during and after basic laparoscopic skills training

Background

Manual dexterity and visual-spatial ability are considered key to the development of superior laparoscopic skills. Nevertheless, these abilities do not reliably explain all the variance found in the technical performance of surgical trainees. Consequently, we must look beyond these abilities to improve our understanding of laparoscopic skills and to better identify/develop surgical potential earlier on.

Purpose

To assess the individual and collective impact of physical, cognitive, visual, and psychological variables on performance during and after basic simulation-based laparoscopic skills training.

Method

Thirty-four medical students (laparoscopic novices) completed a proficiency-based laparoscopic skills training program (using either a 2D or 3D viewing mode). This was followed by one testing session, a follow-up testing session with new (yet similar) tasks, and a series of physical, cognitive, visual, and psychological measures.

Results

The statistical models that best predicted variance in training performance metrics included four variables: viewingmode (2D vs 3D), psychologicalflexibility, perceivedtaskdemands, and manualdexterity (bimanual). In subsequent testing, a model that included viewingmode and manualdexterity (assembly) best predicted performance on the pre-practiced tasks. However, for a highly novel, spatially complex laparoscopic task, performance was best predicted by a model that comprised viewingmode, visual-spatialability, and perceivedtaskdemands. At follow-up, manualdexterity (assembly) alone was the best predictor of performance on new (yet similar) tasks.

Conclusion

By focussing exclusively on physical/cognitive abilities, we may overlook other important predictors of surgical performance (e.g. psychological variables). The present findings suggest that laparoscopic performance may be more accurately explained through the combined effects of physical, cognitive, visual, and psychological variables. Further, the results suggest that the predictors may change with both task demands and the development of the trainee. This study highlights the key role of psychological skills in overcoming initial training challenges, with far-reaching implications for practice.

Laparoscopic skills training: the effects of viewing mode (2D vs. 3D) on skill acquisition and transfer

BACKGROUND

Three-dimensional (3D) visual displays have been suggested to aid laparoscopic skills training by providing the depth cues not present in traditional two-dimensional (2D) displays. However, few studies have robustly investigated the impact of viewing mode (2D vs. 3D) on learning outcomes.

PURPOSE

To examine how viewing mode (2D vs. 3D) impacts the acquisition and transferability of basic laparoscopic skills by comparing performance between transfer and control groups on a complete proficiency-based training program.

METHOD

A counterbalanced between-subjects design was employed. Each participant was randomly allocated to one of four groups, comprising two transfer groups (trained in one viewing mode and tested in the alternate mode: the 2D → 3D and 3D → 2D groups) and two control groups (trained and tested in one viewing mode: the 2D → 2D and 3D → 3D groups). Participants completed proficiency-based training in six laparoscopic training tasks. Testing included two further repetitions of all tasks under test conditions. Objective performance measures included the total number of repetitions to reach proficiency, and total performance scores (i.e. time + error penalties across all repetitions) in training and testing.

RESULTS

The groups trained in 3D demonstrated superior training performance (i.e. less time + errors) and took fewer repetitions to reach proficiency than the groups trained in 2D. The groups tested in 3D also demonstrated superior test performance compared to those tested in 2D. However, training mode did not yield significant test differences between the groups tested in 2D (i.e. 2D → 2D vs. 3D → 2D), or between the groups tested in 3D (i.e. 3D → 3D vs. 2D → 3D).

CONCLUSION

Novices demonstrate superior performance in laparoscopic skills training using a 3D viewing mode compared to 2D. However, this does not necessarily translate to superior performance in subsequent testing or enhanced learning overall. Rather, test performance appears to be dictated by the viewing mode used during testing, not that of prior training.

Laparoscopic Appendectomy Performed by junior SUrgeonS: impact of 3D visualization on surgical outcome. Randomized multicentre clinical trial. (LAPSUS TRIAL)

BACKGROUND

The purpose of this study was to evaluate the effect of 3D visualization applied to laparoscopic appendectomy (LA) performed by young surgeons (YS). We considered both operative features and clinical outcomes, aiming to highlight the benefits that this technology could bring to novice surgeons and their laparoscopic training.

METHODS

All the surgical procedures were performed by residents who had performed less than 20 appendectomies prior to the beginning of the study under the supervision of an expert surgeon. At the time of enrolment patients were randomized into two arms: Experimental arm (EA): laparoscopic appendectomy performed with laparoscopic 3D vision technology. Control arm (CA): laparoscopic appendectomy performed with the "standard" 2D technology. The primary endpoint was to find any statistically significant difference in operative time between the two arms. Differences in conversion rate, intra-operative complications, post-operative complications and surgeons' operative comfort were considered as secondary endpoints.

RESULTS

We randomized 135 patients into the two study arms. The two groups were homogeneous for demographic characteristics, BMI and ASA scores. The characteristics of clinical presentation and anatomical position showed no significant difference. The operative time was longer in the CA (57.5 vs. 49.6 min, p = 0.048, 95% CI). In the subgroup of complicated appendicitis, this trend toward inferior operative time was confirmed without reaching statistical significance (2D = 60 min, 3D = 49.5 min, p = 0.082 95% CI). No intra-operative complications were observed in either group. The conversion rate was 5.6% (4 patients) in the 2D group and 4.6% (3 patients) in 3D group.

CONCLUSION

The utilization of 3D laparoscopy was associated with reduction in operative time without influencing other parameters, in particular without altering the safety profile of the procedure.

Impact of accommodation, convergence and stereoacuity on perceived symptoms and surgical performance among surgeons

BACKGROUND

Minimally invasive surgery (MIS) is not without impact on surgeons' neck/shoulder/head and eyes. However, the mechanisms for concurrent symptoms are not clear. This study aims to examine the effect of visual impairments on physical symptoms and surgical performance among surgeons performing simulated surgical tasks using two-dimensional (2D) and three-dimensional (3D) viewing modes.

METHODS

Gynaecologists with experience in laparoscopy performed four simulated surgical tasks in the 2D and 3D viewing modes. Visual parameters (accommodation, convergence and stereoacuity) were measured prior to commencement. Objective performance measures were derived from the laparoscopic tasks, and surgeons also self-reported their mental and physical workload using the NASA-TLX. In addition, perceived symptoms were measured using Visual Analogue Scales, the Simulator Sickness Questionnaire and the Computer Vision Syndrome Questionnaire.

RESULTS

Seventeen healthy gynaecologists participated in this study. There were significant relationships between visual impairments and both the perceived symptoms and surgical performance scores of MIS surgeons. Surgeons with a higher number of accommodation/convergence dysfunctions and/or poorer stereoacuity tended to have poorer objective performance scores on simulated surgical tasks in both viewing modes. NASA-TLX scores indicated that surgeons with poorer stereoacuity also perceived themselves to have been less successful at accomplishing tasks. However, these surgeons also reported less intense physical symptoms and simulator sickness.

CONCLUSIONS

Surgeons' performance for the simulated surgical tasks correlated with visual functions, and it also impacted on the symptoms experienced. Regular screening of surgeons' vision and vision therapy may be required to decrease physical symptoms and improve surgical performance.

Clinical Application of Virtual Reality for Upper Limb Motor Rehabilitation in Stroke: Review of Technologies and Clinical Evidence

Neurorehabilitation for stroke is important for upper limb motor recovery. Conventional rehabilitation such as occupational therapy has been used, but novel technologies are expected to open new opportunities for better recovery. Virtual reality (VR) is a technology with a set of informatics that provides interactive environments to patients. VR can enhance neuroplasticity and recovery after a stroke by providing more intensive, repetitive, and engaging training due to several advantages, including: (1) tasks with various difficulty levels for rehabilitation, (2) augmented real-time feedback, (3) more immersive and engaging experiences, (4) more standardized rehabilitation, and (5) safe simulation of real-world activities of daily living. In this comprehensive narrative review of the application of VR in motor rehabilitation after stroke, mainly for the upper limbs, we cover: (1) the technologies used in VR rehabilitation, including sensors; (2) the clinical application of and evidence for VR in stroke rehabilitation; and (3) considerations for VR application in stroke rehabilitation. Meta-analyses for upper limb VR rehabilitation after stroke were identified by an online search of Ovid-MEDLINE, Ovid-EMBASE, the Cochrane Library, and KoreaMed. We expect that this review will provide insights into successful clinical applications or trials of VR for motor rehabilitation after stroke.

Efficiency, Accuracy and Clinical Applicability of a New Image-Guided Surgery System in 3D Laparoscopic Liver Surgery

BACKGROUND

To investigate efficiency, accuracy and clinical benefit of a new augmented reality system for 3D laparoscopic liver surgery.

METHODS

All patients who received laparoscopic liver resection by a new image-guided surgery system with augmented 3D-imaging in a university hospital were included for analysis. Digitally processed preoperative cross-sectional imaging was merged with the laparoscopic image. Intraoperative efficiency of the procedure was measured as time needed to achieve sufficient registration accuracy. Technical accuracy was reported as fiducial registration error (FRE). Clinical benefit was assessed trough a questionnaire, reporting measures in a 5-point Likert scale format ranging from 1 (high) to 5 (low).

RESULTS

From January to March 2018, ten laparoscopic liver resections of a total of 18 lesions were performed using the novel augmented reality system. Median time for registration was 8:50 min (range 1:31-23:56). The mean FRE was reduced from 14.0 mm (SD 5.0) in the first registration attempt to 9.2 mm (SD 2.8) in the last attempt. The questionnaire revealed the ease of use of the system (1.2, SD 0.4) and the benefit for resection of vanishing lesions (1.0, SD 0.0) as convincing positive aspects, whereas image registration accuracy for resection guidance was consistently judged as too inaccurate.

CONCLUSIONS

Augmented reality in 3D laparoscopic liver surgery with landmark-based registration technique is feasible with only little impact on the intraoperative workflow. The benefit for detecting particularly vanishing lesions is high. For an additional benefit during the resection process, registration accuracy has to be improved and non-rigid registration algorithms will be required to address intraoperative anatomical deformation.

Comparison of two-dimensional high-definition, ultra high-definition and three-dimensional endovision systems: an ex-vivo randomised study

BACKGROUND

Two-dimensional high-definition (2D HD) endovision system is preferred for laparoscopic surgery. Recently, new generation three-dimensional (3D) HD and ultra-HD (4K) endovision systems are introduced to improve the safety and efficacy of laparoscopic surgery. There is limited evidence on superiority of one technology over the others. This experimental trial was designed to evaluate 2D HD, 3D HD and 4K HD endovision systems in performance of standardized tasks.

METHODS

This was a randomized, cross-over experimental study. Twenty-one surgical residents who were exposed to laparoscopic surgery were enrolled. Participants were randomly assigned into three groups. Each group performed standardised tasks i.e. peg transfer, precision cutting, navigating in space and intra-corporeal suturing using 2D HD, 4K HD and 3D HD endovision systems on a box trainer. Procedures were recorded as 2D HD videos and analysed later. Participant's perceived workload was assessed using Surg-TLX questionnaire. Primary endpoints were execution time in seconds and error score. Secondary endpoint was workload assessment.

RESULTS

The 3D HD had shorter execution time compared to 2D HD and 4K HD in all tasks except precision cutting (p = 0.004, 0.03, 0.001, 0.001 and p = 0.002, 0.191, 0.006, 0.005 in peg transfer, precision cutting, navigating in space and intra-corporeal suturing respectively). The 4K HD was significantly faster than 2D HD only in navigating in space task (p = 0.002). The error score between 3D HD and 4K HD were comparable in all tasks. The 2D HD had significantly more error scores compared to 4K HD, 3D HD in peg transfer task (p = 0.005, 0.014, respectively). 3D HD had significantly less workload than 2D HD and 4K HD in most of the dimensions of Surg-TLX CONCLUSIONS: 3D HD endovision system in comparison to 2D HD and 4K HD, may lead to faster execution without compromising safety of a task and is associated with less workload.

Three-Dimensional Flexible Endoscopy Can Facilitate Efficient and Reliable Endoscopic Hand Suturing: An ex-vivo Study

BACKGROUND/AIMS

Three-dimensional (3D) flexible endoscopy, a new imaging modality that provides a stereoscopic view, can facilitate endoscopic hand suturing (EHS), a novel intraluminal suturing technique. This ex-vivo pilot study evaluated the usefulness of 3D endoscopy in EHS.

METHODS

Four endoscopists (two certified, two non-certified) performed EHS in six sessions on a soft resin pad. Each session involved five stitches, under alternating 3D and two-dimensional (2D) conditions. Suturing time (sec/session), changes in suturing time, and accuracy of suturing were compared between 2D and 3D conditions.

RESULTS

The mean suturing time was shorter in 3D than in 2D (9.8±3.4 min/session vs. 11.2±5.1 min/session) conditions and EHS was completed faster in 3D conditions, particularly by non-certified endoscopists. The suturing speed increased as the 3D sessions progressed. Error rates (failure to grasp the needle, failure to thread the needle, and puncture retrial) in the 3D condition were lower than those in the 2D condition, whereas there was no apparent difference in deviation distance.

CONCLUSION

3D endoscopy may contribute to increasing the speed and accuracy of EHS in a short time period. Stereoscopic viewing during 3D endoscopy may help in efficient skill acquisition for EHS, particularly among novice endoscopists.

Three-dimensional versus two-dimensional high-definition laparoscopy in transabdominal preperitoneal inguinal hernia repair: a prospective randomized controlled study

BACKGROUND

Three-dimensional (3D) laparoscopy improves technical efficacy in laboratory environment, but evidence for clinical benefit is lacking. The aim of this study was to determine whether the 3D laparoscopy is beneficial in transabdominal preperitoneal laparoscopic inguinal hernia repair (TAPP).

METHOD

In this prospective, single-blinded, single-center, superior randomized trial, patients scheduled for TAPP were randomly allocated to either 3D or two-dimensional (2D) TAPP laparoscopic approaches. Patients were excluded if secondary operation was planned, the risk of conversion was high, or the surgeon had less than five previous 3D laparoscopic procedures. Patients were operated on by 13 residents and 3 attendings. The primary endpoint was operation time. The study was registered in ClinicalTrials.gov (NCT02367573).

RESULTS

Total 278 patients were randomized between 5th February 2015 and 23rd October 2017. Median operation time was shorter in the 3D group (56.0 min vs. 68.0 min, p < 0.001). 10 (8%) patients in 3D group and 6 (5%) patients in 2D group had clinically significant complications (Clavien-Dindo 2 or higher) (p = 0.440). Rate of hernia recurrence was similar between groups at 1-year follow-up. In the subgroup analyses, operation time was shorter in 3D laparoscopy among attendings, residents, female surgeons, surgeons with perfect stereovision, surgeons with > 50 3D laparoscopic procedures, surgeons with any experience in TAPP, patients with body mass indices < 30, and bilateral inguinal hernia repairs.

CONCLUSION

3D laparoscopy is beneficial and shortens operation time but does not affect safety or long-term outcomes of TAPP.

Comparison of Short-term Outcomes of Laparoscopic-Assisted Colon Cancer Surgery Using a Joystick-Guided Endoscope Holder (Soloassist II) or a Human Assistant

Purpose

This study aimed to compare the short-term outcomes of laparoscopic-assisted colon cancer surgery in the Soloassist II-assisted (SA) group and in the human-assisted (HA) group.

Methods

A total of 76 patients with colon cancer who underwent laparoscopic-assisted right hemicolectomy and anterior resection performed by a single surgeon between January 2017 and May 2018 were recruited from the consecutively enrolled registry and retrospectively analyzed.

Results

Of 76 patients, 43 underwent surgery with human assistance and 33 underwent surgery using the Soloassist II system. The clinicopathologic characteristics were not statistically different between the 2 groups. In both HA and SA groups, no statistical difference was observed between operation time (220.23 ± 47.83 minutes vs. 218.03 ± 38.22 minutes, P = 0.829), total number of harvested lymph nodes (20.42 ± 10.86 vs. 20.24 ± 8.21, P = 0.938), and other parameters of short-term outcomes (length of hospital stay, blood loss, open conversion, time to flatus, time to soft diet, and complication events). Subgroup analyses did not show statistical differences.

Conclusion

Soloassist II can reduce the participation of a human assistant during surgery and is not inferior to human assistance in laparoscopic-assisted colon cancer surgery. Thus, it is a feasible instrument in laparoscopic-assisted colon cancer surgery that can provide positive short-term outcomes.

Added value of 3D-vision during laparoscopic biotissue pancreatico- and hepaticojejunostomy (LAELAPS 3D2D): an international randomized cross-over trial

BACKGROUND

It is currently unclear what the added value is of 3D-laparoscopy during pancreatic and biliary surgery. 3D-laparoscopy could improve procedure time and/or surgical performance, for instance in demanding anastomoses such as pancreatico- and hepaticojejunostomy. The impact of 3D-laparoscopy could be negligible in more experienced surgeons.

METHODS

We conducted a randomized controlled cross-over trial including 20 expert laparoscopic surgeons and 20 surgical residents from 9 countries (Argentina, Estonia, Israel, Italy, the Netherlands, South Africa, Spain, UK, USA). All participants performed a pancreaticojejunostomy (PJ) and a hepaticojejunostomy (HJ) using 3D- and 2D-laparoscopy on biotissue organ models according to the Pittsburgh method. Primary endpoint was the time required to complete both anastomoses. Secondary endpoint was the objective structured assessment of technical skill (OSATS; range 12-60) rating. Observers were blinded for 3D/2D and expertise.

RESULTS

A total of 40 participants completed 144 PJs and HJs. 3D-laparoscopy reduced the operative time with 15.5 min (95%CI 10.2-24.5 min), from 81.0 to 64.4 min, p = 0.001. This reduction was observed for both experts and residents (13.0 vs 22.2 min, intergroup significance p = 0.354). The OSATS improved with 5.1 points, SD ± 6.3, with 3D-laparoscopy, p = 0.001. This improvement was observed for both experts and residents (4.6 vs 5.6 points, p = 0.519). Of all participants, 37/39 participants stated to prefer 3D laparoscopy whereas 14/39 reported side effects. Minor side effects were reported by 10/39 participants whereas 2/39 participants reported severe side effects (both severe eye strain).

CONCLUSION

3D-laparoscopy, as compared to 2D-laparoscopy, reduced the operative time and improved surgical performance for PJ and HJ anastomoses in both experts and residents with mostly minor side effects.

Endoscopic vitreoretinal surgery: principles, applications and new directions

Purpose

To analyze endoscopic vitreoretinal surgery principles, applications, challenges and potential technological advances.

Background

Microendoscopic imaging permits vitreoretinal surgery for tissues that are not visible using operating microscopy ophthalmoscopy. Evolving instrumentation may overcome some limitations of current endoscopic technology.

Analysis

Transfer of the fine detail in endoscopic vitreoretinal images to extraocular video cameras is constrained currently by the caliber limitations of intraocular probes in ophthalmic surgery. Gradient index and Hopkins rod lenses provide high resolution ophthalmoscopy but restrict surgical manipulation. Fiberoptic coherent image guides offer surgical maneuverability but reduce imaging resolution. Coaxial endoscopic illumination can highlight delicate vitreoretinal structures difficult to image in chandelier or endoilluminator diffuse, side-scattered lighting. Microendoscopy’s ultra-high magnification video monitor images can reveal microscopic tissue details blurred partly by ocular media aberrations in contemporary surgical microscope ophthalmoscopy, thereby providing a lower resolution, invasive alternative to confocal fundus imaging. Endoscopic surgery is particularly useful when ocular media opacities or small pupils restrict or prevent transpupillary ophthalmoscopy. It has a growing spectrum of surgical uses that include the management of proliferative vitreoretinopathy and epiretinal membranes as well as the implantation of posterior chamber intraocular lenses and electrode arrays for intraretinal stimulation in retinitis pigmentosa. Microendoscopy’s range of applications will continue to grow with technological developments that include video microchip sensors, stereoscopic visualization, chromovitrectomy, digital image enhancement and operating room heads-up displays.

Conclusion

Microendoscopy is a robust platform for vitreoretinal surgery. Continuing clinical and technological innovation will help integrate it into the modern ophthalmic operating room of interconnected surgical microscopy, microendoscopy, vitrectomy machine and heads-up display instrumentation.

Three-dimensional Stereoscopic Visualization Shortens Operative Time in Laparoscopic Gastrectomy for Gastric Cancer

Laparoscopic gastrectomy for gastric cancer is now widely accepted and has become a standard surgery. This study investigated the advantages of three-dimensional (3D) stereoscopic visualization for laparoscopic gastrectomy over a conventional two-dimensional (2D) planar screen. The primary outcome of this study was operative time. Ninety-four consecutive cases of gastric cancer patients who underwent laparoscopic total gastrectomy (LTG) (25 cases) or laparoscopic distal gastrectomy (LDG) (69 cases) were enrolled in this study before and after the introduction of the 3D system. Operative time was significantly shorter in the 3D groups for both LTG (351 vs. 406 min, P = 0.026) and LDG (269 vs. 344 min, P < 0.01). During intracorporeal procedures, dissection time was significantly shorter in the 3D groups for both LTG (183 vs. 232 min, P = 0.011) and LDG (161 vs. 213 min, P < 0.01), although the time needed for anastomosis was similar between the groups. However, operators preferred intracorporeal knot-tying as a ligature for anastomosis under 3D (LTG, P = 0.012; LDG, P < 0.01). These data suggest that 3D stereoscopic visualization shortens the operative time of laparoscopic gastrectomy by reducing the intracorporeal dissection time.

The use of 3D laparoscopic imaging systems in surgery: EAES consensus development conference 2018

BACKGROUND

The use of 3D laparoscopic systems is expanding. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

Systematic reviews of the PubMed and Embase libraries were performed to identify evidence on potential benefits of 3D on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by an international surgical and engineering expert panel which were presented and voted at the EAES annual congress, London, May 2018.

RESULTS

9967 abstracts were screened with 138 articles included. 18 statements and two recommendations were generated and approved. 3D significantly shortened operative time (mean difference 11 min (8% [95% CI 20.29-1.72], I² 96%)). A significant reduction in complications was observed when 3D systems were used (RR 0.75, [95 CI% 0.60-0.94], I² 0%) particularly for cases involving laparoscopic suturing (RR 0.57 [95% CI 0.35-0.90], I² 0%). In 69 box trainer or simulator studies, 64% concluded trainees were significant faster and 62% performed fewer errors when using 3D.

CONCLUSION

We recommend the use of 3D vision in laparoscopy to reduce the operative time (grade of recommendation: low). Future robust clinical research is required to specifically investigate the potential benefit of 3D laparoscopy system on complication rates (grade of recommendation: high).

The use of 3D laparoscopic imaging systems in surgery: EAES consensus development conference 2018

BACKGROUND

The use of 3D laparoscopic systems is expanding. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

Systematic reviews of the PubMed and Embase libraries were performed to identify evidence on potential benefits of 3D on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by an international surgical and engineering expert panel which were presented and voted at the EAES annual congress, London, May 2018.

RESULTS

9967 abstracts were screened with 138 articles included. 18 statements and two recommendations were generated and approved. 3D significantly shortened operative time (mean difference 11 min (8% [95% CI 20.29-1.72], I² 96%)). A significant reduction in complications was observed when 3D systems were used (RR 0.75, [95 CI% 0.60-0.94], I² 0%) particularly for cases involving laparoscopic suturing (RR 0.57 [95% CI 0.35-0.90], I² 0%). In 69 box trainer or simulator studies, 64% concluded trainees were significant faster and 62% performed fewer errors when using 3D.

CONCLUSION

We recommend the use of 3D vision in laparoscopy to reduce the operative time (grade of recommendation: low). Future robust clinical research is required to specifically investigate the potential benefit of 3D laparoscopy system on complication rates (grade of recommendation: high).

[3 D laparoscopy versus 2 D laparoscopy : An up to date evaluation]

BACKGROUND

The 3D laparoscopy is currently under intensive discussion. At the moment the majority of newly acquired laparoscopy systems include the 3D technique. New 4K systems, which will be offered in combination with 3D, are complicating the decision-making when buying new laparoscopic systems. The aim of the article is to show the advantages and possible limitations of 3D laparoscopy. Furthermore, the position of 3D laparoscopy in the current video market is evaluated.

MATERIAL AND METHODS

This study was based on an up to date literature search in PubMed. Concerning the question whether the 3D is replacing the 2D laparoscopy, observations from the industry and a personal evaluation were included in the analysis.

RESULTS

The current studies show clear advantages of 3D laparoscopy concerning operation time, efficiency and workload. A major proportion of the studies were conducted on simulation trainers; however, some clinical trials also confirmed these results. The learning curve in laparoscopic surgery is clearly improved with the 3D technique and 3D also seems be useful for operations by experts. The limitation is that not every surgeon can see three dimensionally. Furthermore, the set-up in the operation room needs to be optimized so that a 3D system can be successfully implemented with the nursing staff and side effects, such as exhaustion, dizziness or headache can be prevented.

CONCLUSION

The choice of video system will depend on the personal interest of the surgeon and the ability to see 3D. It can be assumed that the majority of the systems will include 3D laparoscopy but 2D laparoscopy will not be completely replaced. A dynamic development of 3D in association with 4K and robotics can be expected.

Colorectal surgeons should be open to modern surgical technologies for challenging cases

Today, colorectal surgeons globally are practicing in an exciting era where surgical technologies are constantly emerging. Most of these cutting-edge technologies are readily available in Australia and New Zealand at present. Thus the 'modern surgeon' should always be defined by this open-minded attitude towards these new and emerging surgical technologies. This review article highlights current modalities that we have been using in our north-Brisbane public and private hospitals for cases predicted to be technically challenging using minimally invasive approaches for most of them. We examined the current evidence regarding the following modalities and critiqued their use in clinical practice: lighted ureteric stents, minimally invasive surgery approaches of laparoscopy and robotic surgery, pressure barrier insufflation devices, 3D camera systems, hand-assist device ports and indocyanine green dye fluorescence angiography. The objective of this review paper is to alert colorectal surgeons to new surgical technologies available to them, to encourage colorectal surgeons' familiarization with these many technologies, and to support evidence-based consideration for the clinical use of such. These technologies should be supplemental aides to the safe, oncologically adequate and efficient operation that they already routinely perform.

Feasibility and Usefulness of a Joystick-Guided Robotic Scope Holder (Soloassist) in Laparoscopic Surgery

Introduction

The Soloassist® system is a joystick-guided robotic scope holder. We evaluated the efficacy of Soloassist in laparoscopic surgery.

Methods

We investigated operative time, blood loss, set-up time, length of hospital stay, and the number of participating surgeons in laparoscopic cholecystectomy cases before and after the introduction of Soloassist. Furthermore, we evaluated these factors in each group of 20 elective and emergency cholecystectomy cases by single surgeon after matching their background. To evaluate the performance level of operating Soloassist, we divided the operative field into three areas. Then we counted the frequency of energy device activation in initially 10 cases by a single surgical resident and observed its change.

Results

The number of participating surgeons was significantly less and postoperative hospital days were fewer in the Soloassist group. There was no significant difference between set-up time and blood loss both in elective and emergency cases. The total number of energy device activations and that in the dangerous area decreased in accordance with the experience.

Conclusion

Considering our results and previous reports, the combination use of an ideal active scope holder and a commercially available 3D scope is currently considered the best approach in laparoscopic surgery. In the near future, development of active scope holders might play an important role in laparoscopic surgery.

Seeing virtual while acting real: Visual display and strategy effects on the time and precision of eye-hand coordination

Effects of different visual displays on the time and precision of bare-handed or tool-mediated eye-hand coordination were investigated in a pick-and-place-task with complete novices. All of them scored well above average in spatial perspective taking ability and performed the task with their dominant hand. Two groups of novices, four men and four women in each group, had to place a small object in a precise order on the centre of five targets on a Real-world Action Field (RAF), as swiftly as possible and as precisely as possible, using a tool or not (control). Each individual session consisted of four visual display conditions. The order of conditions was counterbalanced between individuals and sessions. Subjects looked at what their hands were doing 1) directly in front of them (“natural” top-down view) 2) in top-down 2D fisheye view 3) in top-down undistorted 2D view or 4) in 3D stereoscopic top-down view (head-mounted OCULUS DK 2). It was made sure that object movements in all image conditions matched the real-world movements in time and space. One group was looking at the 2D images with the monitor positioned sideways (sub-optimal); the other group was looking at the monitor placed straight ahead of them (near-optimal). All image viewing conditions had significantly detrimental effects on time (seconds) and precision (pixels) of task execution when compared with “natural” direct viewing. More importantly, we find significant trade-offs between time and precision between and within groups, and significant interactions between viewing conditions and manipulation conditions. The results shed new light on controversial findings relative to visual display effects on eye-hand coordination, and lead to conclude that differences in camera systems and adaptive strategies of novices are likely to explain these.