Experimental study of a physician-controlled electrocautery-enhanced delivery system incorporating a newly developed lumen-apposing metal stent for interventional endoscopic ultrasound (with videos).

BACKGROUND/PURPOSE: Although the lumen-apposing metal stent (LAMS) is useful for interventional endoscopic ultrasound (EUS) procedures, there has been some concern about the potential for stent-induced adverse events because of the high lumen-apposing force. A newly designed LAMS with less lumen-apposing force has been developed for use with a physician-controlled electrocautery-enhanced delivery system. The aim of this animal study was to evaluate the feasibility of performing interventional EUS using this newly designed LAMS system. METHODS: Endoscopic ultrasound-guided cystogastrostomy was performed using the novel LAMS three times in a wet simulation model. EUS-guided gastroenterostomy and EUS-guided gallbladder drainage were then performed using the system in four pigs. RESULTS: The LAMS was successfully placed in all three EUS-guided cystogastrostomy procedures using the wet simulation model and in all four EUS-guided gastroenterostomy and gallbladder drainage procedures in the animal model. In the 3 weeks following the procedure, eating behavior was normal in all animals and there were no adverse events. The stents remained patent during this time and were removed without difficulty. The fistula was mature in all cases and a standard upper gastrointestinal endoscope was easily advanced via the fistula to observe the afferent and efferent loops or the lumen of the gallbladder. Necropsy confirmed complete adhesion between the stomach and the wall of the jejunum or gallbladder. CONCLUSIONS: Our study findings demonstrate the feasibility of this new LAMS system and its potential clinical value for interventional EUS.

Colonoscopic Ultrasound-Guided Fine-Needle Aspiration Using a Curvilinear Array Transducer: A Single-Center Retrospective Cohort Study.

BACKGROUND: Curvilinear array ultrasound transducers enable tissue sampling and have therapeutic capabilities. Nevertheless, colonic intubation and maneuvering with these transducers is technically challenging and is therefore typically limited to the rectosigmoid area. This retrospective cohort study aimed to evaluate the safety, feasibility, and diagnostic yield of colonoscopic ultrasound-guided fine-needle aspiration in deep colonic intubation. IMPACT OF INNOVATION: The impact of this innovation is to enable tissue sampling of colonic and extracolonic lesions guided by endoscopic ultrasound. TECHNOLOGY, MATERIALS, AND METHODS: Curvilinear array ultrasound is used in the evaluation of luminal and extraluminal colonic diseases. Thirteen patients underwent colonoscopic ultrasound with a curvilinear array ultrasound endoscope in a single center for subepithelial lesions, cancer staging, and extracolonic lesions from July 2015 to February 2021. Endosonography was performed using an Olympus EU-ME1 and GF-UCT 180 with a 5-12MHz curvilinear array transducer. The primary outcome was the percentage of patients who were successfully scanned with the endoscopic ultrasound. The secondary outcomes included the success rate of fine-needle aspiration, the diagnostic yield of the tissue samples, and the adverse events related to the procedure. PRELIMINARY RESULTS: A total of 13 female patients underwent colonoscopic ultrasound. All patients (100%, 13/13) were successfully scanned. Fine-needle aspiration was deemed necessary and successfully performed in 100% (5/5) of the patients. Tissue samples collected by fine-needle aspiration resulted in a diagnostic yield of 60%, and no adverse events resulted from this intervention. CONCLUSIONS: This study demonstrates the feasibility of performing colonoscopic ultrasound with a curvilinear array transducer. Fine-needle aspiration for subepithelial, colonic, and extracolonic lesions is feasible and safe in this setting with no adverse events reported in our study. FUTURE DIRECTIONS: Future research should be directed toward validating colonoscopic ultrasound with a curvilinear array transducer technique in prospective randomized trials. Studies evaluating the feasibility and safety of endoscopic ultrasound-guided interventions in the colon, such as abscess drainage and enteral anastomosis, should be considered.

Utility of Radial Probe Endobronchial Ultrasound Guided Transbronchial Lung Biopsy in Bronchus Sign Negative Peripheral Pulmonary Lesions.

BACKGROUND: The presence of the bronchus sign on chest computed tomography is associated with an increased diagnostic yield of radial probe endobronchial ultrasound-guided transbronchial lung biopsy (RP-EBUS-TBLB). However, the utility of RP-EBUS-TBLB for bronchus sign negative peripheral pulmonary lesions (PPLs) remains unknown. We investigated the utility of RP-EBUS-TBLB in bronchus sign negative PPLs. METHODS: We retrospectively reviewed data from 109 patients who underwent RP-EBUS for bronchus sign negative PPLs from January 2019 to August 2020. TBLB was performed using RP-EBUS with a guide sheath and without fluoroscopy. The EBUS visualization and TBLB diagnostic yields were assessed. Multivariable logistic regression analyses were used to identify factors affecting the EBUS visualization and diagnostic yields. RESULTS: The EBUS visualization yield was 74.1% (68/109). Of the 109 lung lesions, 92 were definitively diagnosed. The overall diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 50.5% (55/109), 34.9% (29/83), 100% (26/26), 100% (29/29), and 32.5% (26/80), respectively. In multivariable analyses, the size of the lesion (≥ 20 mm; odds ratio [OR], 2.62; 95% confidence interval [CI], 1.16-5.93; P = 0.021) and the distance from the pleura (> 10 mm; OR, 2.37; 95% CI, 1.02-5.52; P = 0.045) were associated with EBUS visualization. Regarding diagnostic yield, having the probe within the lesion (OR, 28.50; 95% CI, 6.26-129.85; P < 0.001) and a solid lesion (OR, 14.58; 95% CI, 2.64-80.38; P = 0.002) were associated with diagnostic success. Pneumothorax and hemoptysis occurred in 3.7% (4/109) and 0.9% (1/109), respectively, of the patients. CONCLUSION: RP-EBUS-TBLB using a GS can be considered a diagnostic method in bronchus sign negative solid PPLs. Having the probe within the lesion and a solid lesion were important for diagnostic success. Complication rates were acceptable.

Treatment of Limb Ischemia with Conducted Effects of Catheter-Based Endovascular Ultrasound.

Ultrasound (US) is known to stimulate endogenous shear-dependent pathways, and can lower microvascular resistance through mediators that are conducted downstream from US exposure. We hypothesized that endovascular US, already in use for thrombolysis in humans, can improve tissue perfusion in the setting of acute limb ischemia through downstream-conducted effects. Models of severe peripheral arterial disease were developed in mice and in rhesus macaques. An endovascular US catheter (2.3 MHz, 0.5-1.1 MPa) was used to expose the limb adductor in mice for 10 min or the femoral artery distal to stenosis in macaques for 15 min. Quantitative contrast-enhanced ultrasound perfusion imaging was performed to assess flow augmentation in the adductor muscle of mice and the calf muscle of macaques. Microvascular blood flow in the ischemic limb relative to the contralateral control limb was reduced to 22 ± 8% in mice and 36 ± 20% in macaques. US produced immediate 2.3- and 3-fold increases (p < 0.05) in the murine and macaque ischemic limbs, respectively. In macaques, perfusion in the ischemic limb was increased to a normal level. We conclude that non-cavitating US produced by endovascular catheters that are used to enhance thrombolysis in humans can reduce vascular resistance and increase limb perfusion in the setting of acute ischemia.

Endoscopic drainage for management of infected necrosis following EUS-TA in a patient with pancreatic cancer: A case report.

RATIONALE: Endoscopic ultrasonography-guided tissue acquisition (EUS-TA) has become the norm for the diagnosis of pancreatic solid lesions. EUS-TA is relatively safe, but various complications can occur. Infected pancreatic necrosis (IPN) is a rare but serious complication. The latest guidelines suggest that all invasive interventions in patients with IPN should be delayed until walled-off necrosis appears. PATIENT CONCERNS: A 73-year-old man was referred to our hospital with double primary cancers including gallbladder and pancreas. We performed EUS-TA on metastatic pancreatic tail cancer to confirm histologic diagnosis. Six days after the procedure, he developed abdominal pain and fever. DIAGNOSES: The patient's laboratory findings showed leukocytosis and C-reactive protein elevation. Fluid collection around pancreas tail and stomach was detected in computed tomography (CT) scan, and the patient was diagnosed with IPN. INTERVENTIONS AND OUTCOMES: EUS-guided endoscopic transmural drainage (EUS-TD) was performed for the treatment of IPN. Two days after the procedure with antibiotics, his CRP level decreased abruptly, and he received chemotherapy for the treatment of pancreatic ductal adenocarcinoma (PDAC) 5 days after the procedure. He was discharged from our hospital without complications 15 days after chemotherapy. LESSONS: In selected patients with PDAC, early endoscopic drainage may be recommended as treatment for IPN resulting from complications of EUS-TA.

Double Guidewire Technique Using an Uneven Double Lumen Catheter for Endoscopic Ultrasound-Guided Interventions.

BACKGROUND: Endoscopic ultrasonography (EUS)-guided interventions are often performed using a single guidewire (SGW), but there are a few reports on the use of double guidewire (DGW) technique to facilitate multiple drainage placement during EUS-guided drainage of pancreatic fluid collections. This DGW technique may have advantages other than multiple drainage placement during EUS-guided interventions such as scope stabilization, support for stone extraction and device insertion. METHODS: Consecutive patients who underwent EUS-guided interventions between Feb 2012 and Apr 2019 were retrospectively reviewed. The rate and reasons of DGW technique, and clinical outcomes were evaluated. DGW technique was performed, using an uneven double lumen cannula (UDLC), which facilitates insertion of 0.025-in. and 0.035-in. guidewires. RESULTS: A total of 249 EUS-guided interventions were analyzed, and DGW technique was utilized primarily in 65 cases (25.7%) and as a salvage after failed SGW technique in 18 cases (7.1%). The reasons for DGW technique were 60 multiple drainage placement, 10 scope stabilization, 7 device insertion, 5 safety guidewire, and 4 antegrade stone removal. Insertion of UDLC and DGW was successful in 100%. Technical success rate of preplanned interventions was 92.7% (96.9% in primary DGW and 77.8% in salvage DGW technique). Adverse events were observed in 19.5% after DGW but were not related to DGW technique. CONCLUSIONS: DGW technique using UDLC during EUS-guided interventions was technically feasible and safe. In addition to multiple drainage insertion, it can potentially support complex EUS-guided interventions.

The role of endoscopic doppler probe in the management of bleeding peptic ulcers: a systematic review and meta-analysis.

OBJECTIVES: Forrest classification for ulceration has significant intra and inter-observer variability. The endoscopic doppler probe (DOP-US) identifies arterial blood flow at the base to direct therapy. We performed a systematic review and meta-analysis to evaluate the role of the DOP-US in bleeding peptic ulcers. METHODS: Three independent reviewers performed a comprehensive review of all original articles published from inception to December 2019, evaluating the use of DOP-US in peptic ulcer bleeding. Primary outcomes were the comparison of rebleeding rate, mortality, and surgical intervention in patients with DOP-US signal-guided therapy versus standard visual evaluation guided therapy. RESULTS: Eight studies were included after a thorough search was concluded using the key words. The use of DOP-US probe decreases rebleeding, mortality, and surgical intervention as compared to Forrest Classification. The risk of rebleeding is significantly higher if the signal persists despite endoscopic therapy (48.5% (95% CI 29.5-67.9%)). CONCLUSION: The first systematic review and meta-analysis showed that the DOP-US is a beneficial tool in the management of bleeding ulcers and adds valuable information to visual evaluation.

Endoscopic Ultrasound.

Endoscopic ultrasound provides high-resolution, real-time imaging of the gastrointestinal tract and surrounding extramural structures. In recent years, endoscopic ultrasound has played an increasing role as an adjunct or alternative method to conventional surgical therapies. The role of endoscopic ultrasound in diagnosis and management of gastrointestinal malignancy, pancreatic diseases, and biliary diseases continues to evolve. Therapeutic endoscopic ultrasound procedures for a variety of pancreatic and biliary indications shows a high technical and clinical success rate, with low rate of adverse events. Endoscopic ultrasound plays a key role in multidisciplinary management of complex surgical and oncology patients and those with pancreaticobiliary disorders.

Endoscopic Management of Pancreaticobiliary Disease.

The evolution of advanced pancreaticobiliary endoscopy in the past 50 years is remarkable. Endoscopic retrograde cholangiopancreatography (ERCP) has progressed from a diagnostic test to an almost entirely therapeutic procedure. The endoscopist must have a clear understanding of the indications for ERCP to avoid unnecessary complications, including post-ERCP pancreatitis. Endoscopic ultrasound initially was used as a diagnostic tool but now is equipped with accessary channels allowing endoscopic ultrasound-guided interventions in various pancreaticobiliary conditions. This review discusses the endoscopic management of common pancreatic and biliary diseases along with the techniques, indications, outcomes, and complications of pancreaticobiliary endoscopy.

Endoscopic Equipment-From Simple to Advanced.

Flexible endoscopic procedures, such as esophagogastroduodenoscopies and colonoscopies, allow for diagnosis and treatment of numerous gastrointestinal disorders. Advanced endoscopic procedures, such as endoscopic ultrasounds, endoscopic retrograde cholangiopancreatography, and balloon enteroscopies, offer therapeutic options that are minimally invasive and effective. As technology advances, the equipment and tools in an endoscopist's armamentarium continue to grow. This article highlights key endoscopic equipment and supplies, from simple to advanced.

Revisiting bronchoscopic intratumoral chemotherapy in malignant central airway obstruction via EUS-B approach and its review of literature.

Critical central airway obstruction has always been a dreaded complication to which interventional pulmonologist commonly encounters. There have been various modalities which are used for the management and palliation, which includes mechanical coring, laser, cryoextraction, electrocautery and airway stenting. Rigid bronchoscopy with or without jet ventilation has been corner stone of therapeutics and palliation of central airway obstruction. There are only a few conditions where it is not possible to use rigid bronchoscopy. Here we report a case of metastatic tracheal tumour which presented with critical airway obstruction in a patient who had atlantoaxial instability (AAI) due to rheumatoid arthritis. Here we used endobronchial ultrasound scope (EBUS) via esophageal route, i.e. EUS-B guided approach for sampling of the tracheal tumour, and intratumoral chemotherapy was instilled in multiple sessions, which resulted in shrinking of tumour, thus relieving the critical airway obstruction. This is the first report of using EUS-B approach for intratumoral chemotherapy for tracheal tumors. Bronchoscopic intratumoral chemotherapy therapy (BITC) in tracheal tumors is also one of the options but has not been explored much and there has been a dearth of literature for it.

Endorotor-Based Endoscopic Necrosectomy as a Rescue or Primary Treatment of Complicated Walled-off Pancreatic Necrosis. A Case Series.

Direct endoscopic necrosectomy (DEN) is a cumbersome, time-consuming procedure that can be necessary in cases of infected pancreatic walled-off necrosis (WON) not responding to endoscopic ultrasound (EUS)- guided drainage only. Until now, DEN has been performed with non-dedicated devices, thus requiring multiple, long-lasting sessions to achieve adequate clearance of necrotic content. These results in prolonged hospital stay, increased costs and have potential consequences for patients who must undergo multiple endoscopic interventions under sedation. We report four cases of DEN performed in patients with WON after EUS-guided drainage with the Endorotor system, a new morcellator device specifically designed to perform the procedure.

Las punciones esplénicas ecodirigidas por vía percutánea o guiadas por ecoendoscopia son procedimientos seguros y con un elevado rendimiento diagnóstico / No disponible

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Réplica: "Las punciones esplénicas ecodirigidas por vía percutánea o guiadas por ecoendoscopia son procedimientos seguros y con un elevado rendimiento diagnóstico" / No disponible

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Duodenoscope as a Vector for Transmission.

Elevator-based endoscope-related infections from patient cross-contamination is a multifactorial problem related to device design, maintenance, and function, with additional risk incurred from a high-level disinfection process that lacks quality controls. This article reviews the historical context for these outbreaks, technical aspects of scope design contributing to this risk, and innovations in endoscope technology that have the potential to overcome these shortcomings. Also reviewed are interim solutions and the data that support use of some of these interventions. Still needed are a validated manufacturer-recommended schedule for routine duodenoscope and echoendoscope maintenance with reprocessing protocols that can be implemented in endoscopy units.

Utility of endobronchial ultrasound guided trans-bronchial needle aspiration in diagnosis of melioidosis - case series and review of literature.

Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) is routinely performed for diagnostic evaluation of mediastinal lymphadenopathy due to various etiologies with excellent sensitivity and specificity. Melioidosis can have atypical features like isolated mediastinal lymphadenopathy mimicking as tuberculosis or lymphoma. Differentiation of such atypical melioidosis presentation become difficult due to similar clinical, radiological and even similar EBUS lymph node characteristics. Role of EBUS TBNA in diagnosing melioidosis is under investigated and sparsely reported. We describe two cases of melioidosis diagnosed by point of care rapid lateral flow immunoassay antigen testing and culture of EBUS-TBNA samples from necrotic mediastinal lymph nodes.

Convex probe endobronchial ultrasound guided transbronchial/transoesophageal fine needle aspiration (C-EBUS-TBNA/EUS-B FNA) of pleural lesions: A single center experience and review of literature.

The evaluation of pleural diseases has been well established. If pleurocentensis is non-diagnostic, the second investigation depending upon availability could be either closed pleural biopsy or image guided pleural biopsy or thoracoscopic pleural biopsy (medical or surgical). Pleural disease presenting as thickness/mass/nodule in the mediastinum is difficult to access through ultrasound or computed tomography and will need thoracoscopy. Thoracoscopy is an invasive procedure which can be difficult to perform in localized mediastinal pleural disease without effusion or poor health condition not suitable for general anesthesia. An alternative method that can be utilized is sampling of pleural lesion through convex probe endobronchial ultrasound (CEBUS) either through the central large airways or from esophagus if the lesions are in proximity. We present our center's experience in diagnosing pleural lesion using C-EBUS in 4 patients along with review of the literature.

Regional and Conducted Vascular Effects of Endovascular Ultrasound Catheters.

Intra-vascular ultrasound catheters are used clinically to facilitate clot lysis. We hypothesized that these devices could also directly lower microvascular resistance and increase tissue perfusion through established shear-dependent pathways. In mice, either the proximal hind-limb muscles or the upstream femoral artery alone was exposed to an endovascular ultrasound catheter (2.3 MHz, 0.5-1.1 MPa) for 10 min. Quantitative microvascular perfusion imaging in the hind limbs exposed to the endovascular ultrasound system exhibited a more-than-twofold increase in flow (p < 0.01) compared with the contralateral control limb after exposure of either the muscle or the femoral artery alone. Using an in vivo optical imaging reporting system, an eight- to ninefold increase in tissue adenosine triphosphate (ATP) was detected in the region of insonification (p = 0.006). Ultrasound was found to produce an immediate release of ATP from ex vivo erythrocytes (p = 0.03). In situ electrochemical sensing revealed an immediate increase in nitric oxide with initiation of ultrasound which returned to baseline within 5 min of termination, as well as ultrasound-triggered nitric oxide (NO) release from erythrocytes. These data indicate that non-cavitating ultrasound produced by endovascular catheters can reduce vascular resistance and increase flow through recognized shear-dependent vasodilator pathways involving purinergic signaling and NO.

Theranostic Gastrointestinal Endoscopy: Bringing Healing Light to the Lumen.

Current conventional endoscopes have restricted the accuracy of treatment delivery and monitoring. Over the past decade, there have been major developments in nanotechnology and light triggered therapy, potentially allowing a better detection of challenging lesions and targeted treatment of malignancies in the gastrointestinal tract. Theranostics is a developing form of personalized medicine because it combines diagnosis and targeted treatment delivered in one step using advances in nanotechnology. This review describes the light-triggered therapies (including photodynamic, photothermal, and photoimmunotherapies), nanotechnological advances with nanopowder, nanostent, nanogels, and nanoparticles, enhancements brought to endoscopic ultrasound, in addition to experimental endoscopic techniques, combining both enhanced diagnoses and therapies, including a developed prototype of a "smart" multifunctional endoscope for localized colorectal cancer, near-infrared laser endoscope targeting the gastrointestinal stromal tumors, the concept of endocapsule for obscure gastrointestinal bleed, and a proof-of-concept therapeutic capsule using ultrasound-mediated targeted drug delivery. Hence, the following term has been proposed encompassing these technologies: "Theranostic gastrointestinal endoscopy." Future efforts for integration of these technologies into clinical practice would be directed toward translational and clinical trials translating into a more personalized and interdisciplinary diagnosis and treatment, shorter procedural time, higher precision, higher cost-effectiveness, and less need for repetitive procedures.

Malignant gastric outlet obstruction: Which is the best therapeutic option?

Malignant gastric outlet obstruction (MGOO) is a clinical condition characterized by the mechanical obstruction of the pylorus or the duodenum due to tumor compression/infiltration, with consequent reduction or impossibility of an adequate oral intake. MGOO is mainly secondary to advanced pancreatic or gastric cancers, and significantly impacts on patients' survival and quality of life. Patients suffering from this condition often present with intractable vomiting and severe malnutrition, which further compromise therapeutic chances. Currently, palliative strategies are based primarily on surgical gastrojejunostomy and endoscopic enteral stenting with self-expanding metal stents. Several studies have shown that surgical approach has the advantage of a more durable relief of symptoms and the need of fewer re-interventions, at the cost of higher procedure-related risks and longer hospital stay. On the other hand, enteral stenting provides rapid clinical improvement, but have the limit of higher stent dysfunction rate due to tumor ingrowth and a subsequent need of frequent re-interventions. Recently, a third way has come from interventional endoscopic ultrasound, through the development of endoscopic ultrasound-guided gastroenterostomy technique with lumen-apposing metal stent. This new technique may ideally encompass the minimal invasiveness of an endoscopic procedure and the long-lasting effect of the surgical gastrojejunostomy, and brought encouraging results so far, even if prospective comparative trial are still lacking. In this Review, we described technical aspects and clinical outcomes of the above-cited therapeutic approaches, and discussed the open questions about the current management of MGOO.