Search Results (76)

Endoscopic resection (ER) has become the preferred curative-intent treatment for early upper gastrointestinal cancer, given its superior safety profile compared to surgery. Over the past decade, technological and procedural innovation has substantially expanded the scope, safety, and precision of endoscopic submucosal dissection (ESD) and related techniques. This review synthesises current evidence on key advances relevant to upper gastrointestinal ESD practice. Enhanced imaging modalities have improved lesion detection and characterisation, as well as recognition of intraoperative anatomical structures during third-space endoscopy. A new generation of therapeutic endoscopes combines high-definition optics with substantially improved tip-down angulation and channel size, addressing a longstanding gap between diagnostic-class image quality and procedural capability. Resection strategies—including mechanical traction systems, saline immersion therapeutic endoscopy (SITE), and luminal drainage techniques—have reduced procedural complexity and improved dissection conditions. Dedicated closure technologies have improved management of large resection defects, potentially reducing resection-related morbidity. Deep resection techniques, including submucosal tunnelling endoscopic resection (STER), device-assisted endoscopic full-thickness resection (FTRD), knife-assisted full-thickness resection (kFTR), and endoscopic intermuscular dissection (EID), are extending organ-preserving resection to deeply invasive cancers and subepithelial lesions. Management of non-curative ESD resections is being refined through multicentre risk stratification studies. Advances in simulation, competency-based training, and artificial intelligence hold promise for standardising technique acquisition and real-time procedural support. Together, these innovations are reshaping upper gastrointestinal oncology by positioning minimally invasive, organ-preserving digestive endoscopy as a central therapeutic strategy. Full article

Chronic atrophic gastritis (CAG) is the principal precursor lesion for gastric adenocarcinoma and represents a key target for endoscopic surveillance and early intervention. Although the global age-standardised incidence of gastric cancer has declined over recent decades, the absolute number of cases continues to rise because of population ageing and increasing incidence in younger individuals. The prognosis remains poor in advanced disease, whereas early gastric cancer (EGC) detected at a mucosal stage is associated with excellent long-term survival and may be curable with endoscopic resection. Consequently, high-quality endoscopic detection of premalignant gastric lesions is essential to reduce gastric cancer mortality. This review summarises current concepts in the endoscopic diagnosis of CAG, gastric intestinal metaplasia (GIM), and EGC, from conventional white-light endoscopy through to advanced imaging and artificial intelligence (AI)-assisted systems. Fundamental principles of high-quality oesophagogastroduodenoscopy are discussed, including adequate inspection time, systematic mucosal assessment, mucosal cleansing, and standardised photo-documentation. Characteristic endoscopic appearances of normal gastric mucosa, atrophy, and intestinal metaplasia are reviewed, alongside established staging systems including the Kimura–Takemoto and EGGIM classifications. The role of image-enhanced endoscopy is examined in detail, including narrow-band imaging, linked colour imaging, texture and colour enhancement imaging, and magnification optical enhancement. These modalities improve visualisation of pit patterns, microvascular architecture, and hallmark features of intestinal metaplasia such as the light blue crest sign, substantially increasing diagnostic sensitivity and specificity compared with conventional white light imaging alone. Advanced imaging combined with magnification also enhances the detection and characterisation of EGC. Emerging evidence regarding AI-assisted endoscopy demonstrates promising diagnostic accuracy for CAG, GIM, and early neoplasia, with improved lesion detection and reduced miss rates in several studies. However, limitations relating to external validation, generalisability, and integration into routine practice remain. Continued advances in optical imaging, structured training, and AI-supported diagnostics are likely to play an increasingly important role in improving early gastric cancer detection and surveillance outcomes worldwide. Full article

Freeform optics belong to the increasingly important elements in optical research and industry, which pose several challenges regarding design and highly precise manufacturing. First being used in cameras and for focusing, nowadays freeform optics are used in a broad range of applications, from lighting to LiDAR, from endoscopy to photovoltaics, and from astronomical instruments to quantum cryptography. Designing freeform optics can be based on different theories and methods. Fabrication is possible by mechanical methods, such as diamond turning or high-precision milling, often followed by different polishing techniques, as well as laser-based techniques, mainly applying different lithographic techniques. Here, we give an overview of recent design and optimization methods, production methods used during the last years, and applications of freeform optics, including the possibility to combine freeform optics with tunability for different applications. We describe the opportunities of new applications as well as common problems and give an outlook towards future directions of research and development. Full article

This review summarizes the base materials, joining methods, filler materials, and principal technical challenges in endoscope joining fabrication, and proposes practical strategies to improve joint reliability under clinical constraints. We conducted a comprehensive search in multiple databases, including Web of Science, Google Scholar, patent databases, Scopus databases, and Medline (via PubMed), for articles on the joining for precision endoscope fabrication, covering the period from 1950 to 2026. We employed the combinations of keywords, “endoscopy”, “minimally invasive surgery”, “welding”, “joining”, “sealing”, “soldering”, “bonding”, and “brazing”. Approximately 500 references were retrieved. After excluding duplicates and irrelevant studies, 158 publications met the inclusion criteria. Data on base materials, joining, processes, filler materials, and technical issues related to sterilization, corrosion, and microstructural evolution were extracted and analyzed. Endoscopes are multi-material systems, involving metallic biomaterials (stainless steels (SSs), titanium alloys, nickel-based alloys, etc.), optical functional materials (glass, sapphire, quartz, etc.), engineering plastics, ceramics, composite materials, and coatings. Joining, sealing, and functional integration have been achieved via adhesive bonding, laser soldering, laser brazing, wave soldering, reflow soldering, fusion welding, and other joining techniques. The main challenges include how to reliably join highly mismatched dissimilar materials, how to fabricate low-residual-stress joints, and how to increase the long-term resistance to sterilization-induced degradation and thermal aging over repeated 100–200 °C thermal cycles. Conventional joining techniques struggle to balance mechanical integrity, joint hermeticity, and long-term stability under such harsh cyclic conditions. The resulting joints may suffer surface yellowing, interfacial debonding, microcracking, delamination, or progressive property degradation during service. We propose the following three strategies to achieve reliable, low-residual-stress, and sterilization-resistant joining of dissimilar materials for endoscopes: (1) A synergistic design that combines thin-film engineering (including evaporation, sputtering, and electroplating) with silver anti-oxidation layers is proposed to reduce residual stresses and to enhance the joint hermeticity. (2) To develop principles for the selection of multi-joining processes to achieve the multi-material integration and functional assembly of dissimilar material components. (3) To develop the laser-based joining methods (fusion, brazing, or braze-welding) for precision control of heat input, bonding quality, and the least damage to the heat-sensitive components. Full article

Background: The endoscopic approach to the spine has a steep learning curve, primarily due to challenges in learning how to access Kambin’s triangle, leading to significant radiation exposure. Real-time live instrument tracking using two-dimensional fluoroscopic navigation has been shown to significantly reduce the time and radiation exposure needed to perform a trans-Kambin approach; however, the impact on the learning curve for those in training has not been studied. Methods: Physicians in training (PITs) in a single program were evaluated while accessing Kambin’s triangle using a gel sawbone model. The PITs were randomized in terms of spinal level, the technology used first, and the approach side. Time to access Kambin’s triangle and radiation were recorded for each cohort. A linear regression model was used to assess associations between procedure time and radiation exposure and endoscopic experience and PGY level. Results: Seven PITs were studied with a range of prior experience, consisting of three PITs with high exposure (HE) (≥30 cases) and four with low exposure (LE) (0–20 cases, averaging 7.5). Unassisted by instrument tracking, the SE group was 63% faster and was exposed to 63% less radiation. Further, there was a moderate correlation with experience and time (R = −0.52) and radiation (R = −0.60). Using instrument tracking allowed all the PITs to be 40% faster, taking 6.6 min (range 2.9–12.4) without instrument tracking and 4.0 min (1.9–6.3) with it. Radiation also decreased by 91% (2.52 vs. 0.23 mGy with instrument tracking). Conclusions: Experience significantly enhanced the accessibility of Kambin’s triangle, reducing time and radiation exposure by about two-thirds. Regardless of experience, instrument tracking reduced radiation exposure by 90%. Additionally, familiarizing PITs with instrument location can eliminate 70% of the learning curve for those inexperienced with accessing Kambin’s triangle. Full article

Background: Endoscopic assessment is central to the management of inflammatory bowel disease (IBD), particularly within treat-to-target strategies. However, conventional high-definition white-light endoscopy (HD-WLE) is limited by interobserver variability and its inability to reliably reflect microscopic inflammation or predict long-term outcomes. Over the last decade, multiple technological innovations have reshaped the role of endoscopy in both disease activity monitoring and dysplasia surveillance. Methods: This narrative review provides a comprehensive and clinically oriented overview of emerging endoscopic technologies in IBD, including image-enhanced endoscopy, ultra-high-magnification techniques, artificial intelligence (AI), and molecular imaging. We discuss their diagnostic performance, prognostic implications, and potential integration into clinical practice. Results: Image-enhanced endoscopy improves visualization of subtle mucosal and vascular alterations and demonstrates stronger correlation with histological activity compared with HD-WLE alone. Confocal laser endomicroscopy and endocytoscopy enable in vivo microscopic assessment of epithelial architecture and barrier integrity, redefining remission beyond macroscopic healing. AI systems have shown expert-level performance in grading inflammatory severity in ulcerative colitis and high sensitivity in capsule endoscopy for Crohn’s disease, supporting objective and reproducible assessment. In surveillance, targeted high-definition inspection has replaced random biopsies, while adjunctive optical and AI-based tools enhance lesion detection and characterization. Molecular imaging introduces a predictive dimension by enabling visualization of drug–target engagement and dysplasia-specific pathways. Conclusions: Endoscopy in IBD is evolving from a descriptive modality toward a multimodal precision tool integrating enhanced imaging, AI-driven standardization, and molecular profiling. Although further validation and cost-effectiveness studies are required, these innovations have the potential to improve therapeutic stratification, surveillance strategies, and long-term patient outcomes. Full article

Endoscopy refers to the minimally invasive optical visualization and examination of internal structures within the body. Its significance lies in diagnosing intraluminal tissue abnormalities and assisting therapeutics, especially in the gastrointestinal tract. However, conventional optical endoscopes are limited by their insufficient penetration depth. Although endoscopic ultrasound achieves deeper penetration of up to 10 cm, it suffers from compromised spatial resolution. Recent advances have expanded the role of endoscopy from basic mucosal visualization to precision diagnostics, therapeutic assistance, and even intelligent, remote-assisted procedures. An emerging modality, second near-infrared window (NIR-II, 1000–1700 nm) endoscopy, offers deep tissue penetration, reduced scattering, and a high signal-to-noise ratio. This review discusses the clinical requirements of endoscopy across screening, diagnostics and therapeutics. It provides a comparative assessment of current methodologies, and a particular focus is placed on discussing the promising developments in NIR-II endoscopy. Furthermore, we investigate the transformative potential of integrating artificial intelligence and fifth-generation wireless networks into endoscopic practice. The continued evolution and clinical translation of these technologies, particularly NIR-II endoscopy, hold the promise to fundamentally enhance precision medicine in gastroenterology. Full article

Background: UBE has gained popularity as a minimally invasive alternative to open spinal procedures. However, it raises concerns about potential ocular complications. Despite these concerns, there is a lack of studies evaluating UBE’s impact on retinal microvasculature using objective imaging tools such as OCTA. This study aims to evaluate the effects of UBE on the microvascular structures of the retina and optic nerve using OCTA, and to determine whether UBE poses a risk for perioperative vision loss. Methods: This study included 32 patients who underwent UBE for lumbar stenosis and received ophthalmologic examinations preoperatively, and at postoperative weeks 1 and 4. Patients with systemic or ocular vascular comorbidities were excluded. OCTA parameters including vascular density (VD), foveal avascular zone (FAZ), retinal nerve fiber layer (RNFL), central macular thickness (CMT), and subfoveal choroidal thickness (SFCT) were evaluated using swept-source OCT. Results: No patients experienced clinical vision loss. A statistically significant change was observed over time in FAZ (p = 0.043), VDd superior (p = 0.018), VDd temporal (p = 0.032), and RNFLts (p = 0.032). However, only VDd superior showed a statistically significant decrease at postoperative week 4 compared to baseline (p = 0.050). All other parameters either returned to baseline or showed no significant change. No clinically relevant visual changes were detected. Conclusions: In this study, UBE spinal surgery was not associated with clinically evident visual loss or sustained OCTA-detected microvascular alterations during short-term follow-up. These findings should be interpreted as reflecting the absence of detectable short-term changes rather than definitive evidence of ocular safety. Full article

Confocal laser endomicroscopy (CLE) is an innovative diagnostic modality that facilitates real-time in vivo optical biopsies of various tissues within luminal and ductal structures. Since its introduction in 2004, the application of this tool has broadened from diagnostic purposes to encompass management and prognostic evaluation in fields such as gastroenterology, neurosurgery, urology, and dermatology. This comprehensive review examines the current applications of endomicroscopy in Barrett’s esophagus (BE), inflammatory bowel disease (IBD), and colorectal lesions. Evidence from the literature suggests that CLE offers a potential solution to the diagnostic limitations associated with white-light endoscopy and histology. With a diagnostic accuracy nearly equivalent to that of histology, CLE is emerging as a promising tool to mitigate the delays related to awaiting histology results for clinical and therapeutic decision-making. However, its use is mainly as a complementary diagnostic method rather than an alternative to histopathology or other ancillary studies. Nevertheless, its widespread adoption remains limited, and further research is necessary to ascertain its overall benefits and cost implications of integrating it into patient care. Full article

Multiphoton endomicroscopy (MPEM) has recently become a key development in optical biomedical diagnostics, providing histologically relevant in vivo images that are eliminating both the need for tissue damage during biopsy sampling and the need for dye injections. Due to its ability to visualize structures at the epithelial, extracellular matrix, and subcellular levels, MPEM offers a promising diagnostic method for precancerous conditions and early forms of gastrointestinal (GI) cancer. The high specificity of multiphoton signals—the two-photon fluorescence response of endogenous fluorophores (NADH, FAD), the second-harmonic generation signal from collagen, and others—makes this method a promising alternative to both traditional histology and confocal endoscopy, enabling real-time assessment of metabolic status, intestinal epithelial cell status, and stromal remodeling. Despite the promising prospects of multiphoton microscopy, its practical implementation is progressing extremely slowly. The main factors here include the difficulty of delivering ultrashort pulses with high peak power, which is necessary for multiphoton excitation (MPE), and obtaining these pulses at the required wavelengths to activate the autofluorescence mechanism. One of the most promising solutions is the use of specialized multimode optical fibers that can both induce beam self-cleaning (BSC), which allows for the formation of a stable beam profile close to the fundamental mode, and significantly broaden the optical spectrum, which can ultimately cover the entire region of interest. This review presents the biophysical foundations of multiphoton microscopy of GI tissue, existing endoscopic architectures for MPE, and an analysis of the potential for using novel nonlinear effects in multimode optical fibers, such as the BSC effect and supercontinuum generation. It is concluded that the use of optical fibers in which the listed effects are realized in the tracts of multiphoton endomicroscopes can become a key step in the creation of a new generation of high-resolution instruments for the early detection of malignant neoplasms of the GI tract. Full article

Colonoscopy is central to colorectal cancer (CRC) prevention, and its effectiveness is determined by the quality of mucosal inspection and lesion detection. The adenoma detection rate (ADR) remains the most widely validated quality benchmark due to its strong inverse association with interval CRC. However, reliance on ADR alone is increasingly recognized as insufficient, particularly given the growing understanding of the serrated neoplasia pathway, which contributes up to one-third of sporadic CRCs. This has driven the emergence of complementary metrics, such as the sessile polyp detection rate (SPDR) and adenomas per colonoscopy (APC). Although SPDR offers important advantages for capturing serrated pathology, challenges persist, including interobserver variability, inconsistent pathology thresholds, limited endoscopist training, and the absence of standardized benchmarks. Alongside these evolving metrics, technological advancements such as image-enhanced endoscopy, computer-aided detection, high-definition optics, and distal attachment devices have demonstrated measurable improvements in detecting subtle lesions and reducing operator-dependent variability. Large real-world registries, including GIQuIC, now support the development and validation of composite models that integrate ADR, SPDR, and APC to better reflect the full spectrum of neoplasia detection. As the field advances, redefining colonoscopy quality will require reconciling established metrics with newer indicators that more comprehensively address both conventional adenomas and serrated lesions. Full article

Optical imaging technologies expand gastrointestinal endoscopy beyond white-light endoscopy (WLE), improving visualization of mucosal, vascular, and subsurface features. They are applied to the detection of neoplastic and premalignant lesions, inflammatory diseases, and small bowel and pancreatic disorders, though their validation and readiness for routine practice vary. This review critically evaluates both guideline-endorsed and investigational optical imaging techniques across major gastrointestinal indications, highlighting diagnostic performance, level of validation, current guideline recommendations, and practical challenges to adoption. In Barrett’s esophagus, narrow-band imaging (NBI) is guideline-endorsed, while acetic acid chromoendoscopy is validated in expert centers. For gastric intestinal metaplasia and early gastric cancer, magnifying NBI achieves diagnostic accuracies exceeding 90% and is guideline-recommended, with acetic acid chromoendoscopy aiding in margin delineation. In inflammatory bowel disease, dye-spray chromoendoscopy is the reference standard for dysplasia surveillance, with virtual methods such as NBI, FICE, and i-SCAN serving as practical alternatives when dye application is not feasible. In the colorectum, NBI supports validated optical diagnosis strategies (resect-and-discard, diagnose-and-leave), while dye-based chromoendoscopy improves detection of flat and serrated lesions. Capsule endoscopy remains the standard for small bowel evaluation of bleeding, Crohn’s disease, and tumors, with virtual enhancement, intelligent chromo capsule endoscopy, and AI-assisted interpretation emerging as promising adjuncts. Pancreaticobiliary applications of optical imaging are also advancing, though current evidence is still preliminary. Investigational modalities including confocal laser endomicroscopy, optical coherence tomography, autofluorescence, Raman spectroscopy, and fluorescence molecular imaging show potential but remain largely restricted to research or expert settings. Guideline-backed modalities such as NBI and dye-based chromoendoscopy are established for clinical practice and supported by robust evidence, whereas advanced techniques remain investigational. Future directions will rely on broader validation, integration of artificial intelligence, and adoption of molecularly targeted probes and next-generation capsule technologies, which together may enhance accuracy, efficiency, and standardization in gastrointestinal endoscopy. Full article

Liquid microlenses and their arrays (LMLAs) have emerged as a transformative platform in adaptive optics, offering superior reconfigurability, compactness, and fast response compared to conventional solid-state lenses. This review summarizes recent progress from an application-oriented perspective, focusing on actuation mechanisms, fabrication strategies, and functional performance. Among actuation mechanisms, electric-field-driven approaches are highlighted, including electrowetting for shape tuning and liquid crystal-based refractive-index tuning techniques. The former excels in tuning range and response speed, whereas the latter enables programmable wavefront control with lower optical aberrations but limited efficiency. Notably, double-emulsion configurations, with fast interfacial actuation and inherent structural stability, demonstrate great potential for highly integrated optical components. Fabrication methodologies—including semiconductor-derived processes, additive manufacturing, and dynamic molding—are evaluated, revealing trade-offs among scalability, structural complexity, and cost. Functionally, advances in focal length tuning, field-of-view expansion, depth-of-field extension, and aberration correction have been achieved, though strong coupling among these parameters still constrains system-level performance. Looking forward, innovations in functional materials, hybrid fabrication, and computational imaging are expected to mitigate these constraints. These developments will accelerate applications in microscopy, endoscopy, AR/VR displays, industrial inspection, and machine vision, while paving the way for intelligent photonic systems that integrate adaptive optics with machine learning for real-time control. Full article

Pose estimation and localization within the gastrointestinal tract, particularly the small bowel, are crucial for invasive medical procedures. However, the task is challenging due to the complex anatomy, homogeneous textures, and limited distinguishable features. This study proposes a hybrid deep learning (DL) method combining Convolutional Neural Network (CNN)-based pose estimation and optical flow to address these challenges in a simulated small bowel environment. Initial pose estimation was used to assess the performance of simultaneous localization and mapping (SLAM) in such complex settings, using a custom endoscope prototype with a laser, micromotor, and miniaturized camera. The results showed limited feature detection and unreliable matches due to repetitive textures. To improve this issue, a hybrid CNN-based approach enhanced with Farneback optical flow was applied. Using consecutive images, three models were compared: Hybrid ResNet-50 with Farneback optical flow, ResNet-50, and NASNetLarge pretrained on ImageNet. The analysis showed that the hybrid model outperformed both ResNet-50 (0.39 cm) and NASNetLarge (1.46 cm), achieving the lowest RMSE of 0.03 cm, with feature-based SLAM failing to provide reliable results. The hybrid model also gained a competitive inference speed of 241.84 ms per frame, outperforming ResNet-50 (316.57 ms) and NASNetLarge (529.66 ms). To assess the impact of the optical flow choice, Lucas–Kanade was also implemented within the same framework and compared with the Farneback-based results. These results demonstrate that combining optical flow with ResNet-50 enhances pose estimation accuracy and stability, especially in textureless environments where traditional methods struggle. The proposed method offers a robust, real-time alternative to SLAM, with potential applications in clinical capsule endoscopy. The results are positioned as a proof-of-concept that highlights the feasibility and clinical potential of the proposed framework. Future work will extend the framework to real patient data and optimize for real-time hardware. Full article

Polyp retrieval following colorectal polypectomy remains a critical step for histopathological analysis and determining appropriate surveillance intervals. Despite reported retrieval rates exceeding 90% in the literature, significant heterogeneity persists in clinical practice, particularly for polyps < 10 mm, due to the lack of standardized retrieval methods. This review synthesizes current evidence on polyp retrieval techniques, the impact of lesion size, and device-specific considerations, including suction-based methods, retrieval nets, and other approaches such as the water-bolus and water-slider techniques. We also examine the clinical utility and limitations of the “resect and discard” and “diagnose and leave in situ” strategies, highlighting barriers to widespread implementation such as medico-legal risks, variability in optical diagnosis, and discrepancies across international guidelines. The integration of advanced imaging technologies, including high-definition endoscopy, virtual chromoendoscopy, and artificial intelligence-driven computer-aided diagnosis (CADx), represent promising tools to help in increasing the diagnostic accuracy of diminutive polyps. As post-polypectomy surveillance recommendations remain tethered to histological findings, this review underlines the need for updated, evidence-based frameworks that take into account technological advancements while ensuring diagnostic precision, cost-effectiveness, and patient safety in colorectal cancer prevention. Full article