Comparison of 3D endoscopy and conventional 2D endoscopy in gastric endoscopic submucosal dissection: an ex vivo animal study

Pelvic asymmetry in children with neuromuscular scoliosis: a computed tomography-based 3D analysis

PURPOSE

Pelvic fixation in pediatric neuromuscular patients with scoliosis is performed when significant pelvic obliquity is present. Instrumentation to the pelvis can be technically demanding and challenging, often associated with a high complication rate, prolonged operative time, increased radiation exposure, and increased intraoperative bleeding. The high complexity of the pelvic instrumentation technique, particularly in severe cases, led us to develop computed tomography (CT)-based 3D in a series of 53 consecutive neuromuscular patients. This analysis aimed to improve the understanding of pelvic asymmetry and preoperatively simulate pelvic instrumentation.

METHODS

A CT-based 3D analysis of all pelvises was performed using Mimics software (version 21), segmenting them for analysis in all three planes. We proceeded with the simulation of pelvic instrumentation with iliac screws, obtaining the angle values and corresponding orientations in the three planes for each screw. A total of 53 CT scans were analyzed, corresponding to 36 patients with myelodysplasia and 17 with neuromuscular disorders.

RESULTS

Pelvic asymmetry was observed in 88.6% (47 CT scans) of the patients. This asymmetry indicated that the weight-bearing hemipelvis underwent anatomical changes compared to the contralateral hemipelvis, including opening or closing of the pelvis relative to the sacroiliac joint, pivoting of the hemipelvis in a cephalocaudal or caudocephalic direction, and shortening of the innominate line.

CONCLUSION

The shape of the weight-bearing hemipelvis is closely related to pelvic asymmetry. A distinct pattern was identified, characterized by cephalic or caudal pivoting, greater prominence of the iliac crest, increased distance from the sciatic spine to the coccyx, and shortening of the innominate line. This finding is relevant for surgical planning and pelvic fixation.

LEVEL OF EVIDENCE

IV.

Combined fluorescence lifetime and surface topographical imaging of biological tissue

In this work a combined fluorescence lifetime and surface topographical imaging system is demonstrated. Based around a 126 × 192 time resolved single photon avalanche diode (SPAD) array operating in time correlated single-photon counting (TCSPC) mode, both the fluorescence lifetime and time of flight (ToF) can be calculated on a pixel by pixel basis. Initial tests on fluorescent samples show it is able to provide 4 mm resolution in distance and 0.4 ns resolution in lifetime. This combined modality has potential biomedical applications such as surgical guidance, endoscopy, and diagnostic imaging. The system is demonstrated on both ovine and human pulmonary tissue samples, where it offers excellent fluorescence lifetime contrast whilst also giving a measure of the distance to the sample surface.

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.

Highly flexible and compact volumetric endoscope by integrating multiple micro-imaging devices

A light-field endoscope can simultaneously capture the three-dimensional information of in situ lesions and enables single-shot quantitative depth perception with minimal invasion for improving surgical and diagnostic accuracy. However, due to oversized rigid probes, clinical applications of current techniques are limited by their cumbersome devices. To minimize the size and enhance the flexibility, here we report a highly flexible and compact volumetric endoscope by employing precision-machined multiple micro-imaging devices (MIRDs). To further protect the flexibility, the designed MIRD with a diameter and height of 5 mm is packaged in pliable polyamide, using soft data cables for data transmission. It achieves the optimal lateral resolvability of 31 µm and axial resolvability of 255 µm, with an imaging volume over 2.3 × 2.3 × 10 mm3. Our technique allows easy access to the organism interior through the natural entrance, which has been verified through observational experiments of the stomach and rectum of a rabbit. Together, we expect this device can assist in the removal of tumors and polyps as well as the identification of certain early cancers of the digestive tract.

3D vs. 2D simulated fetoscopy for spina bifida repair: a quantitative motion analysis

3D imaging technology is becoming more prominent every day. However, more validation is needed to understand the actual benefit of 3D versus conventional 2D vision. This work quantitatively investigates whether experts benefit from 3D vision during minimally invasive fetoscopic spina bifida (fSB) repair. A superiority study was designed involving one expert team ([Formula: see text] procedures prior) who performed six 2D and six 3D fSB repair simulations in a high-fidelity animal training model, using 3-port access. The 6D motion of the instruments was recorded. Among the motion metrics are total path length, smoothness, maximum speed, the modified Spectral Arc Length (SPARC), and Log Dimensionless Jerk (LDLJ). The primary clinical outcome is operation time (power 90%, 5% significance) using Sealed Envelope Ltd. 2012. Secondary clinical outcomes are water tightness of the repair, CO[Formula: see text] insufflation volume, and OSATS score. Findings show that total path length and LDLJ are considerably different. Operation time during 3D vision was found to be significantly shorter compared to 2D vision ([Formula: see text] vs. [Formula: see text] min; p [Formula: see text] 0.026). These results suggest enhanced performance with 3D vision during interrupted suturing in fetoscopic SBA repair. To confirm these results, a larger-scale follow-up study involving multiple experts and novice surgeons is recommended.

Effect of 3-Dimensional Imaging Device on Polyp and Adenoma Detection During Colonoscopy: A Randomized Controlled Trial

INTRODUCTION

To evaluate the effect of 3-dimensional (3D) imaging device on polyp and adenoma detection during colonoscopy.

METHODS

In a single-blind, randomized controlled trial, participants aged 18-70 years who underwent diagnostic or screening colonoscopy were consecutively enrolled between August 2019 and May 2022. Each participant was randomized in a 1:1 ratio to undergo either 2-dimensional (2D-3D) colonoscopy or 3D-2D colonoscopy through computer-generated random numbers. Primary outcome included polyp detection rate (PDR) and adenoma detection rate (ADR), defined as the proportion of individuals with at least 1 polyp or adenoma detected during colonoscopy. The primary analysis was intention-to-treat.

RESULTS

Of 1,196 participants recruited, 571 in 2D-3D group and 583 in 3D-2D group were finally included after excluding those who met the exclusion criteria. The PDR between 2D and 3D groups was separately 39.6% and 40.5% during phase 1 (odds ratio [OR] = 0.96, 95% confidence interval [CI]: 0.76-1.22, P = 0.801), whereas PDR was significantly higher in 3D group (27.7%) than that of 2D group (19.9%) during phase 2, with a 1.54-fold increase (1.17-2.02, P = 0.002). Similarly, the ADR during phase 1 between 2D (24.7%) and 3D (23.8%) groups was not significant (OR = 1.05, 0.80-1.37, P = 0.788), while ADR was significantly higher in 3D group (13.8%) than that of 2D group (9.9%) during phase 2, with a 1.45-fold increase (1.01-2.08, P = 0.041). Further subgroup analysis confirmed significantly higher PDR and ADR of 3D group during phase 2, particularly in midlevel and junior endoscopists.

DISCUSSION

The 3D imaging device could improve overall PDR and ADR during colonoscopy, particularly in midlevel and junior endoscopists. Trial number: ChiCTR1900025000.

Comparison of 2D and autostereoscopic 3D visualization during mixed reality simulation

PURPOSE

In general minimally invasive surgical procedures, surgeons are tied to 2D visualization, leading to the loss of depth perception. This can lead to large mental load for the surgeons and may be responsible for the long learning curve. To restore the sense of depth, this study investigated the use and benefits of an autostereoscopic (3D) display during a simulated laparoscopic task.

METHODS

A mixed reality simulator was developed for comparing the performance of participants while using 2D and autostereoscopic 3D visualization. An electromagnetic sensor was mounted on a physical instrument, and its pose was mapped to the virtual instrument. The virtual scene was developed using Simulation Open Framework Architecture (SOFA). Finite element modeling was used to calculate interaction forces, which were then mapped to visual soft tissue deformation.

RESULTS

Ten non-expert participants completed a virtual laparoscopic task, where the subjects were asked to contact eighteen target areas distributed on the surface of the vagina, both in 2D and 3D. Results showed an improvement with 3D vision in task completion time (-16%), total traveled distance (-25%) and errors made (-14%). There was no difference in the average contact forces between the vagina and the instrument. Only the difference in time and forces were shown to be statistically significant.

CONCLUSION

Overall, autostereoscopic 3D showed superiority over conventional 2D visualization. The traveled trajectory increased in 2D as the instrument was retracted more between the targets to avoid contact. The 2D and 3D deformation upon contact seems not to contribute differently to force perception. However, the participants only had visual feedback, but no haptic feedback. Therefore, it could be interesting to include haptic feedback in a future study.

Computational microscopy for fast widefield deep-tissue fluorescence imaging using a commercial dual-cannula probe

A solid-glass cannula serves as a micro-endoscope that can deliver excitation light deep inside tissue while also collecting emitted fluorescence. Then, we utilize deep neural networks to reconstruct images from the collected intensity distributions. By using a commercially available dual-cannula probe, and training a separate deep neural network for each cannula, we effectively double the field of view compared to prior work. We demonstrated ex vivo imaging of fluorescent beads and brain slices and in vivo imaging from whole brains. We clearly resolved 4 μm beads, with FOV from each cannula of 0.2 mm (diameter), and produced images from a depth of ~1.2 mm in the whole brain, currently limited primarily by the labeling. Since no scanning is required, fast widefield fluorescence imaging limited primarily by the brightness of the fluorophores, collection efficiency of our system, and the frame rate of the camera becomes possible.

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.

Three-dimensional light-field microendoscopy with a GRIN lens array

Optical endoscopy has emerged as an indispensable clinical tool for modern minimally invasive surgery. Most systems primarily capture a 2D projection of the 3D surgical field. Currently available 3D endoscopes can restore stereoscopic vision directly by projecting laterally shifted views of the operating field to each eye through 3D glasses. These tools provide surgeons with informative 3D visualizations, but they do not enable quantitative volumetric rendering of tissue. Therefore, advanced tools are desired to quantify tissue tomography for high precision microsurgery or medical robotics. Light-field imaging suggests itself as a promising solution to the challenge. The approach can capture both the spatial and angular information of optical signals, permitting the computational synthesis of the 3D volume of an object. In this work, we present GRIN lens array microendoscopy (GLAM), a single-shot, full-color, and quantitative 3D microendoscopy system. GLAM contains integrated fiber optics for illumination and a GRIN lens array to capture the reflected light field. The system exhibits a 3D resolution of ∼100 µm over an imaging depth of ∼22 mm and field of view up to 1 cm². GLAM maintains a small form factor consistent with the clinically desirable design, making the system readily translatable to a clinical prototype.

Three-dimensional visualization improves the endoscopic diagnosis of superficial gastric neoplasia

BACKGROUND

Three-dimensional (3D) technology has been used in many fields, including flexible endoscopy. We evaluated the usefulness of 3D visualization for endoscopically diagnosing superficial gastric neoplasia.

METHODS

Twelve participants (4 novices, 4 trainees and 4 experts) evaluated two-dimensional (2D) and 3D endoscopic still images of 28 gastric neoplasias, obtained before ESD with white-light imaging (WLI) and narrow-band imaging (NBI). Assessments of the delineation accuracy of tumor extent and tumor morphology under 2D and 3D visualization were based on the histopathological diagnosis of ESD specimens. Participants answered visual analog scale (VAS) questionnaires (0-10, worst to best) concerning the (a) ease of recognition of lesion morphology, (b) lesion extent and (c) comprehensive endoscopic cognition under 2D and 3D visualization. The endpoints were the accuracy of tumor extent and morphology type and the degree of confidence in assessing (a)-(c).

RESULTS

The delineation accuracy of lesion extent [mean (95% confidence interval)] with WLI under 3D visualization [60.2% (56.1-64.3%)] was significantly higher than that under 2D visualization [52.3% (48.2-56.4%)] (P < 0.001). The accuracy with NBI under 3D visualization [70.3% (66.8-73.7%)] was also significantly higher than that under 2D visualization [64.2% (60.7-67.4%)] (P < 0.001). The accuracy of the morphology type with NBI under 3D visualization was significantly higher than that under 2D visualization (P = 0.004). The VAS for all aspects of endoscopic recognition under 3D visualization was significantly better than that under 2D visualization (P < 0.01).

CONCLUSIONS

Three-dimensional visualization can enhance the diagnostic quality for superficial gastric tumors.

Three-dimensional flexible endoscopy enables more accurate endoscopic recognition and endoscopic submucosal dissection marking for superficial gastric neoplasia: a pilot study to compare two- and three-dimensional imaging

BACKGROUND

Three-dimensional (3D) visualization offers better depth recognition than two-dimensional (2D) imaging, thus helping to provide more useful information. We compared 3D and 2D endoscopy with regard to endoscopic recognition and endoscopic submucosal dissection (ESD) marking for superficial gastric neoplasia.

METHODS

ESD marking was performed on half of a neoplasia margin under 2D observation and the on other half under 3D observation for 28 gastric lesions (26 early gastric cancers and 2 adenomas). The accuracy of ESD marking was evaluated based on the distance between the pathological and endoscopic neoplasia margins measured on histology sections of ESD specimens. The technical ease of ESD marking and endoscopic lesion recognition (lesion morphology, lesion extent, and comprehensive endoscopic cognition) were assessed using visual analog scale (VAS) questionnaires.

RESULTS

The mean distance between the pathological and endoscopic margins under 3D observation (1.03 ± 0.80 mm) was significantly (p = 0.002) shorter than that under 2D observation (1.94 ± 1.96 mm). The VAS for technical ease of ESD marking under 3D observation was significantly better (p < 0.01) than that under 2D observation. The VAS for all aspects of endoscopic recognition under 3D observation was significantly better (p < 0.01) than under 2D observation.

CONCLUSIONS

3D flexible endoscopy achieved more accurate endoscopic recognition and ESD marking for superficial gastric neoplasia than a 2D approach in a clinical setting of ESD.

Free flap head and neck microsurgery with VITOMⓇ 3D: Surgical outcomes and surgeon's perspective

OBJECTIVE

To report on the application of the 3D exoscopic system to microsurgery in a cohort of head and neck cancer patients; to analyse the performance of microvascular anastomoses, flap harvesting and insetting under exoscopic view and to evaluate the surgeon's feedback after procedures.

METHODS

An observational study was performed on 10 consecutive patients undergoing exoscopic microsurgical free flap reconstruction. The VITOM^Ⓡ 3D system was applied to all procedures for microsurgical anastomoses, flap harvesting and insetting. Data about the type of resection and reconstruction, intraoperative and post-operative complications were recorded. Surgeon's feedback on exoscopic experience was collected through a questionnaire.

RESULTS

Reconstruction after oncologic demolition was performed by radial forearm flap in 3 cases (30%), antero-lateral thigh flap in 4 cases (40%), composite fibula flap in 2 cases (20%) and chimeric scapula flap in 1 case (10%). The mean surgical time for the microsurgical anastomoses (1 vein and 1 artery) was 34 min (range: 32-38). No intraoperative complications occurred and only two patients experienced pharyngo-cutaneous fistula in the post-operative time. There were neither cases of loss of flap, nor need of surgical revision. None of the cases had to be converted to OM technique. The surgeon never experienced back/neck pain, headache and nausea/vertigo. Occasionally, he felt tired and stressed and he reported eyestrain after one procedure only.

CONCLUSIONS

VITOM^Ⓡ 3D is easy to apply in the field of head and neck microsurgery and provides optimal stereoscopic view and anatomical details. Further studies are needed to validate indications and advantages of 3D exoscope as compared to OM.

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.