Large Caliber Research Articles

A generalized multinomial probabilistic model for SARS-COV-2 infection prediction and public health intervention assessment in an indoor environment.

SARS-CoV-2 Omicron and its sub-lineages have become the predominant variants globally since early 2022. As of January 2023, over 664 million confirmed cases and over 6.7 million deaths had been reported globally. Current infection models are limited by the need for large datasets or calibration to specific contexts, making them difficult to apply to different settings. This study aims to develop a generalized multinomial probabilistic model of airborne infection to assist public health decision-makers in evaluating the effectiveness of public health interventions (PHIs) across a broad spectrum of scenarios. The proposed model systematically incorporates group characteristics, epidemiology, viral loads, social activities, environmental conditions, and PHIs. Assumptions about social distance and contact duration that estimate infectivity during short-term group gatherings have been made. The study is differentiated from earlier works on probabilistic infection modeling in the following ways: (1) predicting new cases arising from more than one infectious person in a gathering, (2) incorporating additional key infection factors, and (3) evaluating the effectiveness of multiple PHIs on SARS-CoV-2 infection simultaneously. Although the results show that limiting group size has an impact on infection, improving ventilation has a much greater positive health impact. The proposed model is versatile and can flexibly accommodate other scenarios or airborne diseases by modifying the parameters allowing new factors to be added.

Development of a Large-Aperture Coordinate Precision Measurement Instrument Using Differential Geometric Error Weighting

The accuracy of traditional measuring machines is affected by the measuring range and sensitive geometric errors, and it is not possible to combine large caliber and high-precision measurements. This study proposes a differential geometric error-weighting method for designing a high-precision, large-diameter measuring machine. The machine utilized a zero-Abbe arm structure and applied the rigid body theory and small-angle hypothesis to model geometric errors. Weights were calculated for 23 geometric errors, identifying eight sensitive ones. A picometer-precision laser interferometer (quDIS) with a theoretical positioning accuracy of 0.2 nm/mm and standard flat rulers are used to ensure highly accurate positioning of the Y-axis/Z-axis of the measuring platform and reduce the straightness of both axes by approximately 75%, with radial and axial runout of the rotary table under 100 nm. The development and design method of the high-precision measuring machine proposed in this study is applicable to large-diameter high-precision flexible measurement, and the accurate control of measuring machine movement accuracy is realized by calculating the geometric error weights.

Characterization of a large caliber explosively driven shock tube.

Research on evaluating weapon systems, building structures, and personnel protection has attracted considerable attention due to the high incidence of blast accidents. The explosively driven shock tube is an affordable and replicable method for investigating high pressure blast waves and extreme shock environments. A newly constructed large caliber explosively driven shock tube with an inner diameter of 2.5m and a length of 18m has been documented and characterized in this paper. It is capable of providing a peak pressure of at least 5.49 MPa in the test section with 160kg of TNT charges. The tube can produce an overpressure that is significantly higher than conventional shock tubes, which expands the capability to simulate a high overpressure blast load. A two-dimensional axisymmetric simulation model has been developed, validated, and calibrated for the characterization of the flow field inside the shock tube. The influence of the charge mass on the overpressure, arrival time, and positive impulse was discussed, and the planarity of the shock wave was also quantitatively characterized. To aid in designing further shock experiments and applications, a physics-based prediction model was developed using the dimensional analysis.

Fruit quality of 'Stanley' plums based on soil composition across diverse agro-ecological zones of Morocco

The national production of plums, especially prunes, is strongly increasing, attracting attention in the local market. This study aims to assess the impact of soil chemical composition on the nutritional and physicochemical quality of plums of the variety ''STANLEY'' (Prunus Domestica L.) across diverse agro-ecological zones of Morocco. Through a preliminary survey of 21 growers in three distinct regions: Sais, Atlas and Oriental. Supplemented by sampling at eight locations in eastern and western Morocco, three categories of parameters were considered in this study: (1) parameters related to cultivation conditions, including climate, geographical structuring, plot size and planting age; (2) those providing information on physico-chemical properties, nutritional value and sugar content; (3) parameters related to soil quality. The surveyed farmers are proprietors of cultivated plots ranging from 6 to 70 hectares, with an average yield of 12T/ h. Notably, 28% of producers with recently established plantations (less than 10 years) have achieved yields exceeding 15T/h, indicating the fertility of trees at this stage of maturity. The findings affirm that soil fertility and soil amendment are the major factors contributing to high-quality fruit (large caliber, high Brix rate, intact product…). Additionally, this study highlights the significance of climate and irrigation in achieving the desired quality of plums.

Prediction of sound around shooting ranges

The assessment of sound around shooting ranges can be challenging. On one hand, methods to predict the sound levels around shooting ranges are described in the standard ISO 17201 "Acoustics - Noise from shooting ranges". It consists of measurement and calculation methods to determine the source strength from muzzle blasts or explosives and supersonic projectiles, as well as a method for the sound propagation. The methods to calculate the muzzle and projectile sound are being updated this year. On the other hand, challenges remain to measure the source strength from weapons with a large caliber and the sound emitted from shooting facilities with a complex geometry. These issues and its approach are illustrated. Also, a noise management method is described, as a pilot study, that allows for a flexible use of different weapons for a given period of time, typically a year.

An update on soil gas harvesting technique as a non-depleting source of 222Rn for a large volume calibration chamber for long-term exposure experiments

ObjectiveTo demonstrate the versatility of the natural soil gas harvesting technique, coupled with a semi-dynamic injection algorithm, as an efficient and reliable source for continuous 222Rn delivery to a large-volume calibration chamber across different soil conditions and climatic conditions. MethodsLong-term experiments were performed during three seasons of a year in a tropical monsoonal climatic region with high rainfall on the Southwest Coast of India. Soil gas extraction was performed using soil-gas probes, inserted to ∼ 1 m deep into the ground. Soil gas was harvested at a flow rate of 60 lpm, passed through a moisture trap, a 222Rn progeny filter, and a delay volume and pumped into a 222Rn calibration chamber of volume 22.7 m3. Continuous monitoring of 222Rn concentration in the chamber was performed using ionization chamber-based reference monitors. To achieve and maintain the desired 222Rn concentration values in the calibration chamber, the semi-dynamic injection method was adopted, in which the 222Rn concentration in the soil gas was monitored periodically, and injection into the chamber was controlled using a well-defined pumping algorithm. Three ranges of 222Rn concentration values were chosen as the target values to be maintained in the calibration chamber for long-term experiments (15 d): (i) low concentration (500 - 1,000 Bq/m3), (ii) medium concentration (1,000 - 10,000 Bq/m3), and (iii) high concentration (10,000 – 25,000 Bq/m3). ResultsThe achieved 222Rn concentration values were in good agreement with the target values, with deviations of 12%, 8% and 5% for the low, medium and high concentration exposures, respectively, during the summer season. During the monsoon season, the deviations between the target and the achieved concentration values were 12%, 10% and 5% for low, medium and high concentration exposures, respectively, and the corresponding deviations were 12%, 4%, and 5% for the winter season. These deviations are well within the cumulative uncertainty associated with the measurements. ConclusionsThe results of this study conclusively demonstrate that the soil gas harvesting method, when coupled with the semi-dynamic injection approach, is a reliable method for generating and maintaining the desired 222Rn concentration in the large volume calibration chamber during different seasons and environmental conditions.

Self-supervised learning of Vision Transformers for digital soil mapping using visual data

In arid environments, prospecting cultivable land is challenging due to harsh climatic conditions and vast, hard-to-access areas. However, the soil is often bare, with little vegetation cover, making it easy to observe from above. Hence, remote sensing can drastically reduce costs to explore these areas. For the past few years, deep learning has extended remote sensing analysis, first with Convolutional Neural Networks (CNNs), then with Vision Transformers (ViTs). The main drawback of deep learning methods is their reliance on large calibration datasets, as data collection is a cumbersome and costly task, particularly in drylands. However, recent studies demonstrate that ViTs can be trained in a self-supervised manner to take advantage of large amounts of unlabelled data to pre-train models. These backbone models can then be finetuned to learn a supervised regression model with few labelled data.In our study, we trained ViTs in a self-supervised way with a 9500 km2 satellite image of dry-lands in Saudi Arabia with a spatial resolution of 1.5 m per pixel. The resulting models were used to extract features describing the bare soil and predict soil attributes (pH H2O, pH KCl, Si composition). Using only RGB data, we can accurately predict these soil properties and achieve, for instance, an RMSE of 0.40 ± 0.03 when predicting alkaline soil pH. We also assess the effectiveness of adding additional covariates, such as elevation. The pretrained models can as well be used as visual features extractors. These features can be used to automatically generate a clustered map of an area or as input of random forests models, providing a versatile way to generate maps with limited labelled data and input variables.

Guidance for Circumflex Scapular Artery Flap Utilization in Pediatric Reconstruction.

The circumflex scapular artery (CSA) flap system, consisting of scapular, parascapular, and chimeric flaps, is useful for pediatric reconstruction in many anatomical locations. The objectives of this case series are to offer insights into our decision-making process for selecting the CSA flap in particular pediatric reconstructive cases and to establish a framework for choosing a scapular or parascapular skin paddle. We also aim to emphasize important technical considerations of CSA flap utilization in pediatric patients. Pediatric reconstruction with CSA flaps performed at our institution between 2006-2022 was retrospectively reviewed. Patient demographics, indications, flap characteristics, complications, and operative data were abstracted. Functional donor site morbidity was assessed through postoperative physical examinations. Unpaired t test analyzed scapular versus parascapular flap size. Eleven CSA flaps were successfully performed in 10 patients (6 scapular and 5 parascapular flaps). Patient ages ranged from 2 to 17 years. Scapular fasciocutaneous free flaps (n = 4) were performed in patients' ages 2-5 years for hand and forearm scar contractures. Two pedicled scapular flaps were performed for a single patient for bilateral axillary hidradenitis suppurativa. The 5 parascapular flaps were performed in patients' ages 2-14 years for calcaneus and forearm avulsion wounds and reconstruction after resection of hidradenitis suppurativa, nevus sebaceous, and Ewing sarcoma. In the sarcoma resection case, a chimeric flap with latissimus dorsi was employed. Average flap size was 101.6 ± 87.3 cm2 (range: 18-300 cm2). Parascapular flaps were significantly larger than scapular flaps (156.60 ± 105.84 cm2 vs 55.83 ± 26.97 cm2, P = 0.0495). Overall, 3 complications occurred (27.3% of cases) including venous congestion (n = 2) and wound dehiscence (n = 1). There were no reported cases of compromised shoulder function at 1.9 ± 2.5-year follow-up. The successful reconstruction rate for scapular, parascapular, and chimeric flaps was 100%. The CSA flap treated a wide variety of indications demonstrating the flap's attributes: large vessel caliber, wide arc of rotation, reliable vascular anatomy, minimal donor site morbidity, and ability to incorporate bone and muscle. Our cases also highlight important pediatric considerations such as vascular mismatch and limited scapular bone stock. We recommend selection of the parascapular over the scapular flap with reconstruction of larger, complex defects given its ability to be harvested with a large skin paddle.

Long-term outcomes of Allium ureteral stent as a treatment for ureteral obstruction

Ureteral obstruction is a prevalent urological condition associated with significant complications. The purpose of our study was to assess the safety and efficacy of a novel self-expanding, large caliber, biocompatible polymer-coated ureteral stent (Allium) for the treatment of ureteral obstructions. We conducted a retrospective analysis of data from patients who underwent Allium ureteral stent placement at our institute between November 2018 and May 2023. Demographic, clinical, and perioperative parameters were collected and analyzed. Logistic regression analyses were performed to identify preoperative factors predicting Allium stent migration. The study cohort comprised 30 patients who received a total of 40 successfully implanted Allium stents. No significant adverse events related to the insertion procedure were observed. During a median follow-up period of 29 months (range: 1–60 months), migration occurred in 11 (27.5%) stents while encrustation was noted in 8 (20%) stents. The median functional duration of the Allium stents was found to be 22 months (range:1–60 months), with an overall functioning rate at last follow-up being recorded as 59.5%. Multivariate analysis revealed that the glomerular filtration rate of the ipsilateral kidney was the sole risk factor predictive of Allium stent migration. With its minimal invasiveness and good tolerability, the Allium stent represents a safe and viable management option for treating ureteric obstructions; however, it should not be considered as definitive treatment but rather as an alternative option for patients unwilling or unsuitable for definitive treatment, particularly high-risk individuals or elderly patients exhibiting decreased ipsilateral glomerular filtration rates.

FREQUÊNCIA DA HOSPITALIZAÇÃO DOS CASOS DE EMBOLIA E TROMBOSE ARTERIAL EM MONTES CLAROS

Arterial thrombosis occurs when the formation of a blood clot completely blocks or impairs the flow of blood from an artery, which are the medium and large caliber vessels in our body responsible for transporting oxygen- and nutrient-rich blood to the tissues. This is a quantitative descriptive study whose data were collected in the Ministry of Health's online program TABNET-DATASUS, related to the municipality of Montes Claros, Minas Gerais. The selected variables were hospitalization by year of processing, age group, sex, color/race, and deaths during the period from 2017 to 2021. It is noted that with the analysis of the results obtained and the literature, that with advancing age, changes occur in normal aging, making individuals more prone to develop diseases, added to unhealthy habits and/or decompensated chronic diseases throughout life becomes even more predisposed.

Rapid-calibration optical tunable delay line on 3-µm-thick SOI photonic platforms

Optical tunable delay lines (OTDLs) which can capture temporal optical signals, and overcome the challenge of halting light are crucial for optical communications and microwave photonics. Here, a rapid-calibration 8-bit OTDL on the 3-µm-thick silicon-on-insulator (SOI) platform consisting of waveguide spirals and integrated optical switches is proposed, achieving a maximum delay time of 3570 ps with a resolution of 14 ps/stage. The large delay is attributed to the spirals of a 3-µm-thick SOI platform featuring a delay efficiency of approximately 11.49 ps/mm, with wavelength-insensitivity transmission loss of 0.32 dB/cm, and the polarization-dependent loss is only 0.075 dB/cm within 140 nm bandwidth. In addition, the optical switches with extinction ratios up to 50 dB. Integrated variable optical attenuators can suppress crosstalk and facilitate rapid calibration for OTDLs. The advantages of OTDLs’ large delay time, high signal-to-noise, and rapid calibration make them suitable for optical programmers and microwave photonics radars.

The Circulasome: A Unifying Theory of Flap Vascularity.

Despite the critical roles of nondominant perforators, choke vessels, and direct and indirect linking vessels in flap vascularity, current models of flap perfusion focus on a primary large caliber perforators. The delay phenomenon, microvascularization, neovascularization, and vascular evolution, which depend on smaller caliber vessels, remain unaccounted for. We propose that the "circulasome" consists of the sum of the entire vascular components of a given region, such that the region is supplied by a primary supplying vessel. The circulasome represents one of the indices of flap supply and is proportional to the angiogenic potential of the region and the vascular substrate capable of promoting growth of vascular networks. By accounting for both the primary flap supplying vessel and secondary vascular structures, the circulasome provides a unifying explanation for neovascularization, delay phenomenon, angiosome and perforasome theories, and vascular evolution in flaps.

Outcomes of endoscopic ultrasound-guided gallbladder drainage: A multicenter study from India (with video).

Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) offers a safe and minimally invasive alternative for percutaneous cholecystostomy (PCC) in acute cholecystitis patients with high-surgical risk. Additionally, EUS-GBD serves as a rescue biliary drainage in malignant distal biliary obstruction. Despite its widespread application, data within the Indian context remains sparse. This study aims to report the outcomes of EUS-GBD through the first multi-center study from India. We retrospectively analyzed patients undergoing EUS-GBD at six tertiary care centers of India from March 2022 to November 2023. EUS-GBD was performed by free hand or over-the-guidewire technique with lumen-apposing metal stent (LAMS) or large caliber metal stent (LCMS). The primary outcome was technical success (defined as successful deployment of stent between gallbladder and stomach/duodenal lumen). The secondary outcomes were clinical success (defined as resolution of symptoms of acute cholecystitis and more than > 50% reduction in bilirubin level within two weeks in distal biliary obstruction), adverse event rate, 30-day mortality rate and 90-day reintervention rate. Total29 patients (mean age 65.86 ± 12.91, 11 female) underwent EUS-GBD. The indication for EUS-GBD were acute cholecystitis (79.31%) and rescue biliary drainage for malignant distal biliary obstruction (20.69%). LAMS was deployed in 92.86%, predominantly by free-hand technique (78.57%). Technical and clinical success rates were 96.55% and 82.75%, respectively. Adverse events occurred in 27.59% patients, with severe adverse events (bile leak and bleeding) being uncommon (10%). Both 30-day mortality rate and 90-day reintervention rate were 13.79% in patients. Cholecysto-duodenal fistula facilitated cholecystoscopic intervention and stone removal in one patient and transgastric EUS-GBD did not hamper bilio-enteric anastomosis during Whipple surgery in two patients. EUS-GBD is a safe and effective technique for managing acute cholecystitis in high-risk patients and for biliary drainage in cases with malignant distal biliary obstruction.

Robust generalised predictive position control for chain‐type rotary shell magazine with disturbance observer

AbstractThe realisation of fast position tracking control and strong robust control of the chain‐type rotary shell magazine in the complex systems such as the large calibre howitzer has been the focus and challenge of research. The predictive control strategies can achieve a fast dynamic response, but it relies on the system model. By integrating the generalised predictive control method with sliding mode theory, a novel robust generalised predictive position control method is proposed. Firstly, a non‐cascade position tracking controller is designed based on the continuous‐time model of the systems; then, a sliding mode compensation structure is introduced to address the degradation of control performance due to load variations and external disturbances. The scheme utilises the sliding mode switching term to overcome the effects caused by the disturbances while preserving the fast dynamic response characteristics of the original predictive control. Moreover, the disturbance observer is designed to further enhance the robustness by producing corresponding compensation according to the perturbation quantity. The proposed controller has been validated in a shell magazine test bench, indicating its superior position control performance of the shell magazine under different load conditions.

Comparative analysis of morphological changes in the mucosa of the small and large bronchi in non-small cell lung cancer

Background. Despite advances in surgical and therapy techniques, non-small cell lung cancer (NSCLC) is one of the most common cancers and the leading cause of cancer-related death. Therefore, it is increasingly important to search for markers that predict the risk of tumor progression. The study of the morphology of the epithelium of the bronchi of different calibers has great potential for solving this problem. The aim of the study was to comparatively evaluate the characteristics and frequency of occurrence of various combinations of morphological changes in the epithelium of the bronchi of large and small calibers in patients with lung squamous cell carcinoma and lung adenocarcinoma. Material and methods. lung samples were collected from 151 NSCLC patients (stage T1–4N0–3M0), who underwent surgery at the cancer Research institute, TNRMC. Various morphological changes in the bronchial epithelium were analyzed. Results. The study of the frequency of occurrence of various morphological changes in small-caliber bronchi showed that basal cell hyperplasia occurred in 90.8 % of cases. Diffuse isolated basal cell hyperplasia was observed in 33.8 % of cases. Focal basal cell hyperplasia was diagnosed in 38.4 % of cases. A combination of basal cell hyperplasia with squamous metaplasia was observed in 18.5 % of cases. The study of the frequency of occurrence in large-caliber bronchi demonstrated that basal cell hyperplasia was the most common morphological variant (93.4 %, including diffuse isolated basal cell hyperplasia in 33.8 % and focal basal cell hyperplasia in 38.4 %). The combination of basal cell hyperplasia and squamous metaplasia was found in 19.8 %. The combination of basal cell hyperplasia with squamous metaplasia and dysplasia was found in 1.3 % compared to the epithelium of small-caliber bronchi. Conclusion. The obtained results on the frequency of occurrence of morphological changes in large-caliber bronchi are of theoretical interest for further research to identify groups at high risk of progression of non-small cell lung cancer.

Analyzing barrel surface damage in failed large caliber cannons

To elucidate the surface damage characteristics of artillery barrel bores, a dissected 155 mm failed barrel was analyzed. Utilizing macroscopic imaging, SEM and EBSD for characterization, distinct damage patterns were identified. The rifling and forcing cone regions predominantly exhibited fatigue crack patterns, while the mid-bore region also showed signs of fatigue cracks. Notably, the groove region demonstrated frictional wear features. Both the grooves and the lands region at the muzzle end were characterized by frictional wear. A significant finding was the presence of a heat-affected layer along the bore surface, extending from the breech end to the muzzle, with its thickness gradually decreasing. The radial hardness of the bore surface demonstrated a decreasing trend, with the hardness of the heat-affected layer being about double that of the matrix material. The formation of this layer was attributed to the high-energy impact loads the bore surface endures, involving a cycle of high temperature and rapid cooling. This process induces recrystallization, sub-grain structure formation, and continuous grain refinement alongside dislocation annihilation.

Use of Phase-Angle Model for Full-Field 3D Reconstruction under Efficient Local Calibration.

Currently, 3D reconstruction methods in structured light are generally implemented in a pre-calibrated area. To realize a full-field reconstruction, the calibration plate can be moved to multiple positions in a time-consuming manner, or the whole field can be calibrated with the help of a large calibration plate, which is more costly. In this paper, we address this problem by proposing a method for obtaining a global phase-angle model under a locally calibrated region, and based on this relationship, we investigate and analyze the reconstruction inside and outside of the calibrated zone. The results show that the method can reconstruct the object outside of the calibration zone completely, and can keep the planarity error around 0.1 mm and the sphericity error below 0.06 mm. The method only requires local calibration of the projected fringes at the two calibration positions to realize the 3D reconstruction of the full-field, which makes the method more advantageous.

Recent Patents for Optical Alignment

Background: The installation of optical devices is a necessary operation before their use. Therefore, the configuration of the optical system affects the performance of the whole optical system. However, in the process of optical system installation, there are still some technical breakthroughs to be made in order to better carry out optical system installation in the future. Objective: Through the introduction and discussion of the devices, methods and patent features of optical alignment testing in recent years, some valuable conclusions are summarized, and future research and development are prospected. Methods: The patents of optical system assembly were studied, and the patents and research progress of optical alignment were summarized. Results: With the development of optical technology, optical alignment has become more and more important, so optical alignment is needed to realize the design of optical systems. Conclusion: It is concluded that there is still a large space for the development of optical alignment, and the main development trend is towards high precision and large caliber

High-precision binocular camera calibration method based on a 3D calibration object.

A high-precision binocular camera calibration method is proposed to address the issues of poor calibration accuracy and large calibration errors in current practical applications. This method uses a triangular stereo sphere as the calibration object and employs steps, such as ellipse fitting, Cholesky decomposition, homography matrix solution, and nonlinear optimization, to compute the intrinsic and extrinsic parameters, distortion parameters, and relative pose of the binocular camera. Moreover, this method simplifies the correspondences between primitives, enabling simultaneous calibration of multiple viewpoint cameras. This method is also suitable for both binocular cameras consisting of two different structured monocular cameras and those composed of two image sensors within the same structure. Experimental results showed that this method outperforms traditional algorithms in terms of binocular camera calibration accuracy, calibration errors between left and right cameras, and robustness, resulting in a significant improvement in overall algorithm performance.

A novel method of bilateral biliary decompression by EUS-guided hepaticogastrostomy with bridging stenting using the partial stent-in-stent method for reintervention of multiple metal stent failure

Video 1A novel method of bilateral biliary decompression by EUS-guided hepaticogastrostomy with bridging stenting using the partial stent-in-stent method for reintervention of multiple metal stent failure.We report a case in which anterior and posterior drainage was performed using the partial stent-in-stent method via the transpapillary approach. The patient had a bismuth type IV biliary obstruction, but only the right hepatic lobe was drained due to obstruction of the left portal vein. For the recurrent stent dysfunction, the patient underwent placement of a plastic stent within an uncovered self-expanding metal stent to correct stent dysfunction. A 7F plastic stent inside a metal stent is shown.The patient later experienced stent failure and jaundice due to tumor progression and was admitted for plastic stent replacement. Neither imaging results nor symptoms suggested duodenal stenosis. The transpapillary approach was attempted first but was unsuccessful. Duodenoscopy was challenging to perform because of duodenal stenosis. Fluoroscopy confirmed the duodenal stenosis. The plastic stent was extracted using an upper endoscope. Multiple uncovered metal stents are shown (1 stent in the anterior bile duct and 2 stents in the posterior bile duct). Jaundice did not resolve despite plastic stent removal.The patient refused to undergo percutaneous biliary drainage, so a decision was made to perform an EUS-guided hepaticogastrostomy (HGS) instead. The left bile duct was observed in the stomach. The left bile duct was punctured with a 19-gauge FNA needle. A 0.025-inch hydrophilic guidewire was directed into the left bile duct. Enhancement of the bile duct showing malignant hilar biliary obstruction (bismuth IV) is seen. Insertion of the guide wire into the posterior bile duct is shown.The stent mesh was then dilated using a balloon dilator. However, there was difficulty inserting the catheter. Additional dilation was performed using a spiral dilator. This instrument is a tapered tip dilator that fits into 0.025-inch guidewires and is expandable to 7F. Insertion of a second guidewire with a larger caliber was done to straighten the bile duct and help stabilize stent insertion. A 0.035-inch hydrophilic guidewire into the posterior bile duct using a double-lumen cannula and insertion of a 0.025-inch hydrophilic guidewire into the anterior bile duct are shown.The stent mesh was then dilated using a spiral dilator. A metal stent was placed through the anterior bile duct at a steep angle. Insertion and deployment of the first uncovered self-expanding metal stent (8× 60mm) from the anterior bile duct into the left bile duct is shown. Multiple metal stents were implanted into the hilar area, and the new stent was placed using the partial stent-in-stent method to prevent overexpansion. Guidewire seeking the posterior bile duct from inside the deployed stent through the stent mesh is shown.The stent mesh was then dilated using a balloon dilator. Insertion and deployment of an uncovered self-expanding metal stent (8× 60mm) from the posterior bile duct to the left bile duct using the partial stent-in-stent method is shown. Enhancement of the bile duct shows drainage from the right bile duct. The fistula of the HGS was only dilated with the spiral dilator. The risk of bile leakage was low, so we decided to implant a plastic stent. A 7F× 15-cm plastic stent was placed from the posterior bile duct into the stomach. Anterior and posterior segment drainage by EUS-HGS with bridging stenting using the partial stent-in-stent method is shown, with left segment drainage by EUS-HGS with the plastic stent.We performed EUS-HGS on a patient with multiple metal stents in place. There were no adverse events, and total bilirubin levels were reduced by more than half within 2 weeks. Six months have passed without stent dysfunction.