3D Endoscopy Research Articles

Totally 3D endoscopic aortic valve replacement: initial results and experience from a single center.

This study aimed to evaluate the feasibility and initial outcomes of totally endoscopic aortic valve replacement (TEAVR) performed via a single working port at the fourth intercostal space (ICS) utilizing a 3D endoscopic system. A retrospective observational study was conducted on 35 consecutive patients who underwent TEAVR over a six-month period from December 2023 to June 2024. Patient selection was based on the presence of isolated aortic valve disease without the need for ascending aorta replacement or aortic root enlargement. A 4 cm single working port was created at the 4th ICS, extending from the right mid-axillary to the anterior axillary line. A 10-mm trocar for a 3D endoscope was placed at the right anterior-axillary line. Peripheral cardiopulmonary bypass (CPB) was established. The primary outcomes investigated included the success rate of the procedure, in-hospital mortality, and perioperative complications. The mean age of the patients was 58.7 ± 12.8 years, with 22.9% being female. The majority of patients (77.1%) presented with aortic stenosis, often accompanied by severe calcification. The medianCPB time was 210 ± 43 min, and the median aortic cross-clamp time was 132 ± 41 min. The procedure was successfully completed in all patients using the endoscopic approach, with no conversions to full sternotomy. Two mortalities were recorded, attributed to postoperative complications including bleeding and cerebral infarctions. The early (30-day) mortality rate was 5.7%. Prolonged mechanical ventilation (>48 h) was required in 17.1% of patients, and reoperation for bleeding was necessary in 2.9% of patients. TEAVR is a feasible procedure with the potential to replace the traditional sternotomy approach for aortic valve replacement.

3D 4K Exo-Endoscopic Temporal Bone Dissection: A Novel Approach for Sharing the Anatomy.

Temporal bone dissection is overwide recognized as an ideal training method for otologic surgeons. The knowledge of temporal bone anatomy and especially of the course of infratemporal facial nerve is pivotal in practice. The 3D exoscope is an innovative and promising tool, that was recently introduced in ear surgery. A high-definition 3D exoscope (3D VITOM®) mounted on the VERSACRANETM holding system (Karl Storz) was used to perform two temporal bone dissection, with the aim to study the anatomy of infratemporal facial nerve. The 3D endoscope (TIPCAM®1 S 3D ORL, Karl Storz) was used in combination to provide a close-up high-quality view and to provide a different angle of view on fine anatomical relationships. The high-definition 3D exoscope allowed to conduct the dissection with high quality visualization and to share the same surgical field with trainees. Moreover, it showed a high interchangeability with the 3D endoscope. 3D 4K Exo-endoscopic temporal bone dissection seems to have benefits in terms of educational purpose, especially concerning anatomy understanding. The superiority in teaching value of this tool should be further investigated in cohort studies.

A Super-Resolution and 3D Reconstruction Method Based on OmDF Endoscopic Images.

In the field of endoscopic imaging, challenges such as low resolution, complex textures, and blurred edges often degrade the quality of 3D reconstructed models. To address these issues, this study introduces an innovative endoscopic image super-resolution and 3D reconstruction technique named Omni-Directional Focus and Scale Resolution (OmDF-SR). This method integrates an Omnidirectional Self-Attention (OSA) mechanism, an Omnidirectional Scale Aggregation Group (OSAG), a Dual-stream Adaptive Focus Mechanism (DAFM), and a Dynamic Edge Adjustment Framework (DEAF) to enhance the accuracy and efficiency of super-resolution processing. Additionally, it employs Structure from Motion (SfM) and Multi-View Stereo (MVS) technologies to achieve high-precision medical 3D models. Experimental results indicate significant improvements in image processing with a PSNR of 38.2902 dB and an SSIM of 0.9746 at a magnification factor of ×2, and a PSNR of 32.1723 dB and an SSIM of 0.9489 at ×4. Furthermore, the method excels in reconstructing detailed 3D models, enhancing point cloud density, mesh quality, and texture mapping richness, thus providing substantial support for clinical diagnosis and surgical planning.

Оцінка показників стереоендоскопічних систем в ринології

This research examines the advantages and disadvantages of 3D endoscopy compared to traditional 2D endoscopy for sinus surgery. It has been found that 3D endoscopy significantly improves depth perception, the brightness of the surgical field, and intraoperative visualization, making it particularly useful for training and understanding anatomy. Despite these benefits, 3D endoscopy can cause discomfort in surgeons, including dizziness, eye strain, and headaches. The development of automated visualization systems based on stereo cameras can enhance procedural accuracy. The use of personalized physical models created through rapid prototyping increases the effectiveness of training systems. However, the need to wear 3D glasses and the difficulty in cleaning the lenses remain issues. Future prospects include the application of such systems in telemedicine services for remote consultations.

Calibration for endoscopic 3D shape measurement with cone beam projection

We demonstrate a calibration method for endoscopic three-dimensional shape measurement with cone beam projection. In this method, changes in the shape of the optical sectioning profiles are quantified and fitted while scanning a calibration board in the depth direction, using a cubic function. In accuracy tests using a flat plate and a ring reference gauge, the proposed method obtains an accuracy of 0.02 mm in the depth dimension and 0.09 mm in the radial dimension. These results represent 88% and 55% improvements compared to previous analysis. For medical applications, an ear examination simulator was employed, and our measurement results were compared to ground truth data obtained by microfocus X-ray computed tomography. The surface deviation of our method relative to the ground truth data was ±0.36mm during manual operation. A comparison of the measurement results before and after calibration revealed an improvement in the peak agreement with the ground truth data, with the deviation shifting from 0.2 mm to −0.05mm. Our strategy achieves a digital transformation of 3D endoscopy, which would benefit a number of medical fields.

Observation of Clinical Effects of 3D Endoscopy in Total Thyroidectomy and Central Lymph Node Dissection

Objective: The main focus of this study is to explore the clinical effects of 3D endoscopy in total thyroidectomy and central lymph node dissection. Methods: Eighty patients undergoing thyroid cancer total thyroidectomy at Shengjing Hospital, China Medical University, from February 2017 to March 2018, were divided into two groups. The experimental group, consisting of 40 patients, underwent treatment using 3D endoscopy, while the control group, also comprising 40 patients, underwent treatment using 2D endoscopy. A comparison was made between the two groups in terms of the incidence of adverse reactions and relevant clinical indicators. Results: Whether in terms of surgical time, blood loss, or postoperative drainage, the experimental group performed better than the control group. Additionally, there were no significant differences between the two groups in postoperative hospital stay, lymph node dissection frequency, lymph node metastasis quantity, and cost. Regarding the incidence of adverse reactions, the experimental group and the control group were 7.50% and 30.00%, respectively, with the former significantly lower than the latter, and the difference between the two groups was statistically significant. Conclusion: 3D endoscopy exhibits good clinical effects in total thyroidectomy and central lymph node dissection, effectively improving patient outcomes, and is worthy of promotion.

Surgical Navigation in the Anterior Skull Base Using 3-Dimensional Endoscopy and Surface Reconstruction

Image guidance is an important adjunct for endoscopic sinus and skull base surgery. However, current systems require bulky external tracking equipment, and their use can interrupt efficient surgical workflow. To evaluate a trackerless surgical navigation system using 3-dimensional (3D) endoscopy and simultaneous localization and mapping (SLAM) algorithms in the anterior skull base. This interventional deceased donor cohort study and retrospective clinical case study was conducted at a tertiary academic medical center with human deceased donor specimens and a patient with anterior skull base pathology. Participants underwent endoscopic endonasal transsphenoidal dissection and surface model reconstruction from stereoscopic video with registration to volumetric models segmented from computed tomography (CT) and magnetic resonance imaging. To assess the fidelity of surface model reconstruction and accuracy of surgical navigation and surface-CT model coregistration, 3 metrics were calculated: reconstruction error, registration error, and localization error. In deceased donor models (n = 9), high-fidelity surface models of the posterior wall of the sphenoid sinus were reconstructed from stereoscopic video and coregistered to corresponding volumetric CT models. The mean (SD; range) reconstruction, registration, and localization errors were 0.60 (0.24; 0.36-0.93), 1.11 (0.49; 0.71-1.56) and 1.01 (0.17; 0.78-1.25) mm, respectively. In a clinical case study of a patient who underwent a 3D endoscopic endonasal transsphenoidal resection of a tubercular meningioma, a high-fidelity surface model of the posterior wall of the sphenoid was reconstructed from intraoperative stereoscopic video and coregistered to a volumetric preoperative fused CT magnetic resonance imaging model with a root-mean-square error of 1.38 mm. The results of this study suggest that SLAM algorithm-based endoscopic endonasal surgery navigation is a novel, accurate, and trackerless approach to surgical navigation that uses 3D endoscopy and SLAM-based algorithms in lieu of conventional optical or electromagnetic tracking. While multiple challenges remain before clinical readiness, a SLAM algorithm-based endoscopic endonasal surgery navigation system has the potential to improve surgical efficiency, economy of motion, and safety.

High-resolution rectoscopy using MHz optical coherence tomography: a step towards real time 3D endoscopy

Colonoscopy and endoscopic ultrasound play pivotal roles in the assessment of rectal diseases, especially rectal cancer and inflammatory bowel diseases. Optical coherence tomography (OCT) offers a superior depth resolution, which is a critical factor for individualizing the therapeutic concept and evaluating the therapy response. We developed two distinct rectoscope prototypes, which were integrated into a 1300 nm MHz-OCT system constructed at our facility. The rapid rotation of the distal scanning probe at 40,000 revolutions per minute facilitates a 667 Hz OCT frame rate, enabling real-time endoscopic imaging of large areas. The performance of these OCT-rectoscopes was assessed in an ex vivo porcine colon and a post mortem human in-situ colon. The OCT-rectoscope consistently distinguished various layers of the intestinal wall, identified gut-associated lymphatic tissue, and visualized a rectal polyp during the imaging procedure with 3D-reconstruction in real time. Subsequent histological examination confirmed these findings. The body donor was preserved using an ethanol-glycerol-lysoformin-based technique for true-to-life tissue consistency. We could demonstrate that the novel MHZ-OCT-rectoscope effectively discriminates rectal wall layers and crucial tissue characteristics in a post mortem human colon in-situ. This real-time-3D-OCT holds promise as a valuable future diagnostic tool for assessing disease state and therapy response on-site in rectal diseases.

Virtual Hall sensor triggered multi-MHz endoscopic OCT imaging for stable real-time visualization.

Circumferential scanning in endoscopic imaging is crucial across various disciplines, and optical coherence tomography (OCT) is often the preferred choice due to its high-speed, high-resolution, and micron-scale imaging capabilities. Moreover, real-time and high-speed 3D endoscopy is a pivotal technology for medical screening and precise surgical guidance, among other applications. However, challenges such as image jitter and non-uniform rotational distortion (NURD) are persistent obstacles that hinder real-time visualization during high-speed OCT procedures. To address this issue, we developed an innovative, low-cost endoscope that employs a brushless DC motor for scanning, and a sensorless technique for triggering and synchronizing OCT imaging with the scanning motor. This sensorless approach uses the motor's electrical feedback (back electromotive force, BEMF) as a virtual Hall sensor to initiate OCT image acquisition and synchronize it with a Fourier Domain Mode-Locked (FDML)-based Megahertz OCT system. Notably, the implementation of BEMF-triggered OCT has led to a substantial reduction in image jitter and NURD (<4 mrad), thereby opening up a new window for real-time visualization capabilities. This approach suggests potential benefits across various applications, aiming to provide a more accurate, deployable, and cost-effective solution. Subsequent studies can explore the adaptability of this system to specific clinical scenarios and its performance under practical endoscopic conditions.

Safety and outcome of three-dimensional transoral videolaryngoscopic surgery.

Transoral videolaryngoscopic surgery (TOVS) is widely used in Japan, and conventional two-dimensional (2D) endoscopic methods have been established. Three-dimensional (3D) endoscopic surgery offers superior distance perception because it provides stereoscopic views. Recently, we have developed 3D endoscopy for TOVS (3D TOVS). This study included 46 patients with pharyngeal cancer who underwent 3D TOVS. The perioperative complications and survival curves were retrospectively analyzed. One patient with oropharyngeal cancer who underwent neck dissection and transoral resection simultaneously experienced postoperative hemorrhage of the neck. Another patient with oropharyngeal cancer underwent hemostasis for postoperative pharyngeal hemorrhage. There was one case of aspiration pneumonia. One patient developed cervical lymph node recurrence; however, there was no local recurrence or primary mortality. The 2-year overall survival, disease-specific survival, local control rates, locoregional control rate, and invasive disease-free survival were 90.9%, 100%, 100%, 97.4%, and 79.9%, respectively. Three-dimensional endoscopy can be safely applied to TOVS.

Surface Reconstruction of the Pediatric Larynx via Structure from Motion Photogrammetry: A Pilot Study.

Endoscopy is the gold standard for characterizing pediatric airway disorders, however, it is limited for quantitative analysis due to lack of three-dimensional (3D) vision and poor stereotactic depth perception. We utilize structure from motion (SfM) photogrammetry, to reconstruct 3D surfaces of pathologic and healthy pediatric larynges from monocular two-dimensional (2D) endoscopy. Models of pediatric subglottic stenosis were 3D printed and airway endoscopies were simulated. 3D surfaces were successfully reconstructed from endoscopic videos of all models using an SfM analysis toolkit. Average subglottic surface error between SfM reconstructed surfaces and 3D printed models was 0.65 mm as measured by Modified Hausdorff Distance. Average volumetric similarity between SfM surfaces and printed models was 0.82 as measured by Jaccard Index. SfM can be used to accurately reconstruct 3D surface renderings of the larynx from 2D endoscopy video. This technique has immense potential for use in quantitative analysis of airway geometry and virtual surgical planning.

Fine tuning for totally endoscopic mitral valve surgery: ERAS applications.

One of the philosophies of minimally invasive mitral surgery is to enhance recovery after surgery (ERAS). Beyond surgical applications, ERAS applications provide a complementary approach to optimize postoperative course and discharge. In this report, we aim to present institutional protocol for ERAS and its results in patients who underwent totally endoscopic mitral valve surgery (TEMVS). Between 2021 and 2023, totally 113 patients who underwent TEMVS were included in this study. TEMVS was performed by peripheral cannulation and 3D endoscopic technique. As a dedicated team, institutional ERAS protocols which are used are listed above: (1) Education; operative course, cessation of smoking and alcohol. (2) Anemia; diagnostic evaluation and its treatment by iv iron. (3) Optimization of blood glucose; checking of HbA1c and control of hyperglycemia. (4) Rehabilitation; Physical and pulmonary rehabilitation. (5) Anxiety and Analgesia treatment. (6) Blood Conservation techniques; Antifibrinolytic, acute normovolemic hemodilution, less priming volume, mini-incision, meticulous surgery by 3D endoscope. (7) Postoperative; early extubation, prevention of nausea, aggressive analgesia, early mobilization, early removal of tubes. (8) Restrictive transfusion strategy. (9) Early discharge. The mean age was 54.7 years, and 56% was female. The rate of iv iron therapy for anemia was 26.5%. Mitral repair was performed in 58.4% of the cases. The repair rate of degenerative mitral valve was 96.9%. Of all, 68.1% did not have any red packed cells and 15.9% had only one unit. Ninety-five patients (90.2%) did not have any unit of fresh frozen plasma. The median extubation time was 7 h. On the postoperative first day, 96% of foley catheters, 87% of all central venous catheter and 93% of all drainage tubes are removed. The rates of respiratory, infectious, and renal complications were 9%, 3.5%, 3.4% respectively. The median ICU, and hospital stays were 1 and 5 days respectively. There was only one mortality in the early postoperative period. Totally endoscopic mitral valve surgery provides minimal surgical trauma. By the addition of well-established and nurse-based ERAS protocols, complication and transfusion rates can be decreased, early recovery and discharge can be provided.

Self-supervised neural network-based endoscopic monocular 3D reconstruction method

Self-supervised neural network-based endoscopic monocular 3D reconstruction method

Clinical comparison of unilateral biportal endoscopic transforaminal lumbar interbody fusion verse 3D microscope-assisted transforaminal lumbar interbody fusion in the treatment of single-segment lumbar spondylolisthesis with lumbar spinal stenosis: a retrospective study with 24-month follow-up

ObjectiveTo explore the safety and the mid-term efficacy of unilateral biportal endoscopic transforaminal lumbar interbody fusion (UBE-TLIF) and 3D microscope-assisted transforaminal lumbar interbody fusion (MMIS-TLIF) for treating single-segment lumbar spondylolisthesis with lumbar spinal stenosis (DLS-LSS).MethodsThe clinical data of 49 patients who underwent UBE-TLIF or MMIS-TLIF in our hospital were retrospectively analyzed, including 26 patients who underwent the UBE-TLIF and 23 patients who underwent the MMIS-TLIF. The demographic and perioperative outcomes of patients before and after surgery were reviewed. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate the clinical outcomes of patients before surgery and at 1, 3, 6, 12 and 24 months after surgery. The lumbar lordosis angle (LL), disc height (DH) and lumbar intervertebral fusion rate were assessed before surgery and at the last follow-up.ResultsThe VAS and ODI scores of the two groups were improved compared with those before surgery. The ODI of UBE-TLIF group was lower than that of MMIS-TLIF group at 1, 3, 6, and 12 months after surgery, and there were no significant differences between the two groups at other time points (P > 0.05). There were no significant differences in VAS between the two groups at each time point (P > 0.05). However, the UBE-TLIF group had more advantages in blood loss and hospital stay. The complications between the UBE-TLIF group (11.54%) and the MMIS-TLIF group (17.39%) were comparable (P > 0.05). Radiographic outcomes showed that the LL and DH of the two groups were improved compared with those before surgery, and the difference before and after surgery was not significant (P > 0.05). The fusion rate was 96.2% in the UBE-TLIF group and 95.7% in the MMIS-TLIF group. There was no significant difference in the fusion rate between the two groups (P > 0.05).ConclusionsBoth UBE-TLIF and MMIS-TLIF have favorable outcomes for treating single-segment DLS-LSS. Both groups have the advantages of clear surgical vision, high surgical efficiency, and favorable mid-term efficacy. In addition, compared with MMIS-TLIF, UBE-TLIF causes less intraoperative bleeding and faster postoperative recovery.

Endoscope 3D reconstruction based on ORB-SLAM

Minimal invasive surgery (MIS) is the mainstream trend in developing surgical technology. As the endoscope is a significant tool in the surgical process, whether it can track the inner cavity and realize accurate real-time 3D reconstruction has a vital impact on the smooth progress of MIS. However, there are still problems in the endoscopic environment, such as severe image distortion, the effect of lighting conditions, and the inability to extract lumen textures. Orinted fast and rotated brief simultaneous localization and mapping (ORB-SLAM) is currently a relatively advanced simultaneous localization and mapping (SLAM) method with better performance. The ORB-SLAM-based endoscope 3D reconstruction method can improve performance and overcome the challenge of endoscope 3D reconstruction. This paper will first introduce several existing endoscope 3D reconstruction methods based on ORB-SLAM and analyze the limitations and issues of these methods through their experimental results. Then the paper will explore the solutions to the defects in this method from other methods and compare the characteristics and the result of experiments. Secondly, through the summary of the above methods and the introduction of the integration of the ORB-SLAM-based methods and other current advanced technologies, the future development trend and huge development potential of ORB-SLAM-based endoscopic 3D reconstruction are introduced. This paper will be of profound affection to further improve the optimization and application of the ORB-SLAM-based endoscope 3D reconstruction method.

3D Heterogeneous Database for Structural Analysis of Historic Buildings. A Discussion on Process Pipelines

This paper presents a methodology for creating a comprehensive heterogeneous 3D database for the structural evaluation of a historic building by using both non-destructive and destructive surveys combined with historical information. The availability of adequate data on the actual conditions is crucial when assessing the seismic vulnerability and structural behavior of a historic building and validating the results. A reliable 3D database must accept different kinds of data, e.g., the results of destructive/non-destructive surveys, historical information, etc. It must also be interrogated and enriched at any time. Therefore, creating such a 3D database may present several challenges in terms of data-gathering pipeline, comprehensiveness/redundancy, interpretation, organization, and integration with other heterogeneous data. The methodology we present in this paper includes 3D laser scanning, thermal imaging, and endoscopy combined with information regarding the state of conservation, construction history, materials, and techniques. We tested such methodology to create a database that was later used for Finite Element Modeling (FEM) to assess the seismic vulnerability of Diotti Palace, a neoclassical building that has been the seat of the Prefect of Milan since 1859. The results are analytically presented here. In conclusion, we highlight the pros and cons of the proposed methodology by means of a comparative discussion with the state of the art about 3D documentation pipelines for historic buildings and sites.

Evaluation of The Three-Dimensional Endoscopy in Basic and Extended Nasal Procedures: A Clinical and Cadaveric Study.

Introduction The three-dimensional (3D) endoscope is considered a new surgical tool used in different approaches in intranasal and anterior skull base surgical procedures. There are many advantages of 3D over two-dimensional (2D) endoscopy that have been demonstrated in clinical applications, surgical training, and different experimental studies. Objective To show the difference between using the 3D and 2D endoscopes during endonasal and anterior skull base surgery and its importance. Methods Our study is divided into two phases (clinical and cadaveric phases). In the clinical study we, have performed 52 endonasal and anterior skull base surgical procedures (26 study cases and 26 control cases). We recorded accuracy, duration, and intraoperative complication for each case. The cadaveric study was performed on three cadavers. Differences in accuracy and dissection time were recorded using 3D and 2D endoscopy for each side chosen by randomization. Results In the clinical study, the cases done by 3D endoscope were significantly faster and more accurate with less intraoperative complications compared with cases done using 2D endoscope. In cadaveric dissection, while using 3D endoscope, there was better depth of perception regarding the anatomical landmarks compared with 2D endoscope. Conclusion Three-dimensional endoscopy is an advanced instrument that allows better training for the coming generation of ear, nose, and throat surgeons. Both clinical and cadaveric studies offer a promising outcome in both endonasal and anterior skull base surgery.

Femoral or Axillary Cannulation for Extracorporeal Circulation during Minimally Invasive Heart Valve Surgery (FAMI): Protocol for a Multi-Center Prospective Randomized Trial.

Minimally invasive heart valve surgery via anterolateral mini-thoracotomy with full endoscopic 3D visualization (MIS) has become the standard treatment of patients with valvular heart disease and low operative risk over the past two decades. It requires extracorporeal circulation and cardioplegic arrest. The most established form of arterial cannulation for MIS is through the femoral artery and is used by most surgeons, but it is suspected to increase the risk of stroke through retrograde blood flow. An alternative route of cannulation is the axillary artery, producing antegrade blood flow during extracorporeal circulation. Femoral or axillary cannulation for extracorporeal circulation during minimally invasive heart valve surgery (FAMI) is a multicenter randomized controlled trial designed to determine whether axillary cannulation is superior to femoral cannulation for the outcome of a manifest stroke within 7 days postoperatively. The target sample size was 848 participants. Patients ≥ 18 years of age, with valvular regurgitation or stenosis scheduled for minimally invasive surgery via anterolateral mini-thoracotomy, were randomized to axillary cannulation (treatment group) or to femoral cannulation (standard care). Patients were followed up for seven days postoperatively. A CT scan was performed pre-operatively to screen patients for vascular calcifications and to assess the safety of femoral cannulation. The standard of care is femoral artery cannulation, but is performed only in patients without significant vascular calcifications or severe kinking of the iliac arteries and in patients with sufficient vessel diameter. The cannulation is performed via Seldinger's technique, and the vessel closed percutaneously using a plug-based vascular closure device. Only patients without significant vascular calcifications are considered for femoral cannulation, as an increased risk of stroke is assumed. In patients with vascular calcifications, axillary cannulation is the standard of care to avoid these risks. Retrospective studies have hinted that, even in patients without vascular calcifications, there may be a lower stroke risk with axillary cannulation compared to femoral cannulation. We present a protocol for a multi-center randomized trial to investigate this hypothesis. To date, evidence on the best access for peripheral artery cannulation during minimally invasive heart valve surgery has been scarce. Patients may benefit from axillary cannulation for extracorporeal circulation in terms of stroke risk and other neurological and vascular complications, though femoral cannulation is the gold standard. The aim of this study is to determine the risks of peri-operative stroke in a prospective randomized comparison of femoral vs. axillary cannulation.

Single and multi-frame auto-calibration for 3D endoscopy with differential rendering.

The use of 3D measurement in endoscopic images offers practicality in cancer diagnosis, computer-assisted interventions, and making annotations for machine learning training data. An effective approach is the implementation of an active stereo system, using a micro-sized pattern projector and an endoscope camera, which has been intensively developed. One open problem for such a system is the necessity of strict and complex calibration of the projector-camera system to precisely recover the shapes. Moreover, since the head of an endoscope should have enough elasticity to avoid harming target objects, the positions of the pattern projector cannot be tightly fixed to the head, resulting in limited accuracy. A straightforward approach to the problem is applying auto-calibration. However, it requires special markers in the pattern or a highly accurate initial position for stable calibration, which is impractical for real operation. In the paper, we propose a novel auto-calibration method based on differential rendering techniques, which are recently proposed and drawing wide attention. To apply the method to an endoscopic system, where a diffractive optical element (DOE) is used, we propose a technique to simultaneously estimate the focal length of the DOE as well as the extrinsic parameters between a projector and a camera. We also propose a multi-frame optimization algorithm to jointly optimize the intrinsic and extrinsic parameters, relative pose between frames, and the entire shape.Clinical relevance- One-shot endoscopic measurement of depth information is a practical solution for cancer diagnosis, computer-assisted interventions, and making annotations for machine learning training data.

Two- and three-dimensional endoscopic endonasal surgery of large and giant pituitary adenomas-outcome analysis of a series of 62 patients from a single pituitary center.

To analyze the perioperative course and clinical outcome of patients with large (lPA) and giant (gPA) pituitary adenoma who underwent endoscopic endonasal transsphenoidal surgery (EETS) using either two-dimensional (2D-E) or three-dimensional (3D-E) endoscopic systems. Single-center retrospective study of consecutive patients with lPA and gPA who underwent EETS between November 2008 and January 2023. LPA were defined as ≥ 3cm and < 4cm in diameter in at least one dimension and a volume of ≥ 10ccm; gPA were defined as larger than 4cm in diameter and with a greater volume than 10ccm. Patient data (age, sex, endocrinological and ophthalmological status) and tumor data (histology, tumor volume, size, shape, cavernous sinus invasion according to the Knosp classification) were analyzed. 62 patients underwent EETS. 43 patients were treated for lPA (69.4%) and 19 patients for gPA (30.6%). 46 patients (74.2%) underwent surgical resection using 3D-E and 16 patients 2D endoscopy (25.8%). Statistical results are referred to the comparison between 3D-E and 2D-E. Patients' age ranged from 23-88years (median 57), 16 patients were female (25.8%), 46 male (74.2%). Complete tumor resection was possible in 43.5% (27/62), partial resection in 56.5% (35/62). Resection rates did not differ between 3D-E (27 patients [43.5%]) and 2D-E (7 patients [43.8%], (p = 0.985). Visual acuity improved in 30 of 46 patients with preoperative deficit (65.2%). In the 3D-E group 21 of 32 patients (65.7%) improved, compared to 9 of 14 patients in the 2D-E group (64.3%). Improvement of visual field was achieved in 31 of 50 patients (62.0%; 22 of 37 patients in the 3D-E group [59.4%] and 9 of 13 patients in the 2D-E group [69.2%]). CSF leak was the most frequent complication and occurred in 9 patients (14.5%, [8 patients 17.4% 3D-E]) without statistical significance. Other surgical complications like postoperative bleeding, infection (meningitis) and deterioration of visual acuity and field were detected without statistical difference. New pituitary anterior lobe dysfunction was observed in 30 of 62 patients (48.4%, 8 patients [50.0%] in the 2D-E group and 22 patients [47.8%] in the 3D-E group). A transient deficit of posterior lobe was detected in 22.6% (14/62). No patient died within 30days of surgery. Although 3D-E may improve surgical dexterity, in this series of lPA and gPA it was not associated with higher resection rates compared to 2D-E. However, 3D-E visualization during resection of large and giant PA is safe and feasible and patient's clinical outcome is not different compared to 2D-E.