Transbronchial Cryobiopsy Using the Ultrathin 1.1-mm Cryoprobe with Ultrathin Bronchoscopy under Radial Endobronchial Ultrasound Guidance for Diagnosis of Peripheral Pulmonary Lesions.

INTRODUCTION: Today, the increasing number of incidentally detected peripheral pulmonary lesions (PPLs) within and outside lung cancer screening trials is a diagnostic challenge. This fact encourages further improvement of diagnostic procedures to increase the diagnostic yield of transbronchial biopsy, which has been shown to have a low complication rate. The purpose of this study was to evaluate the safety and feasibility of a new ultrathin 1.1 cryoprobe that can be placed through an ultrathin bronchoscope (UTB) using fluoroscopy and radial endobronchial ultrasonography (rEBUS) navigation for assessing PPLs. METHODS: Thirty-five patients with PPL less than 4 cm in diameter were prospectively enrolled to receive transbronchial cryobiopsies (TBCBs) using the ultrathin 1.1-mm cryoprobe. Navigation to the PPL was accomplished with the UTB. Under rEBUS and fluoroscopy guidance up to 4 cryobiopsies were obtained. The sample sizes of the biopsies were compared to a historic collective derived from a 1.9-mm cryoprobe and standard forceps. The feasibility and safety of the procedure, the cumulative and overall diagnostic yield, and the cryobiopsy sizes were evaluated. RESULTS: After detection with the rEBUS, TBCB was collected from 35 PPLs, establishing a diagnosis in 25 cases, corresponding to an overall diagnostic yield of 71.4%. There was no difference in diagnostic yield for PPL <20 mm or ≥20 mm. All cryobiopsies were representative with a mean tissue area of 11.9 ± 4.3 mm2, which was significantly larger compared to the historic collective (p = 0.003). Six mild and four moderate bleeding events and 1 case of pneumothorax were observed. CONCLUSIONS: Using the ultrathin 1.1-mm cryoprobe combined with an UTB for rEBUS-guided TBCB of PPL is feasible and safe. This diagnostic approach improves bronchoscopic techniques for diagnosing peripheral lung lesions and may contribute to improve diagnosis of lung cancer even in small PPL.

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.

Bent peripheral venous catheter inserted using ultrasound-guided dynamic needle tip positioning.

Herein, we report the case of a 2-year-old boy in whom a bent peripheral venous catheter was inserted using ultrasound-guided dynamic needle tip positioning via a short-axis out-of-plane approach. The peripheral venous catheter appeared to be successfully inserted into the cephalic vein in the forearm using dynamic needle tip positioning via a short-axis out-of-plane approach. However, after removing the inner needle, no blood return was confirmed. The removed catheter was noted to be bent at approximately one-third of the catheter length from the tip. A large change in the puncture angle during dynamic needle tip positioning for a deeply located vein might have caused this bend. Deeply located veins are not targeted when a blind puncture technique is used, as they are not visible and palpable. They can be visualized by ultrasonography and can be targeted using DNTP; however, the catheter may bend. Clinicians should be aware of this issue and, therefore, they are suggested to ensure that the puncture angle is not too steep and use a long length catheter; in addition, very deep veins should not be targeted.

Real-Time Ultrasound-Guided Versus Ultrasound-Assisted Spinal Anesthesia in Elderly Patients With Hip Fractures: A Randomized Controlled Trial.

BACKGROUND: Traditional landmark-guided spinal anesthesia can be challenging in elderly patients with hip fractures. Ultrasound assistance (USAS) and real-time ultrasound guidance (USRTG) techniques can facilitate lumbar neuraxial blocks. However, it remains undetermined which method is optimal for use in elderly patients. This study aimed to evaluate which technique was associated with a higher success rate of spinal anesthesia in elderly patients with hip fractures: USAS or USRTG technique. METHODS: A total of 114 elderly patients (≥70 years of age) with hip fractures were randomly assigned to receive spinal anesthesia using either the USAS or USRTG technique. The primary outcome was the first-attempt success rate, analyzed using the χ2 test. Secondary outcomes included first-pass success rate, the number of needle attempts and passes, locating time, procedure time, total time, adverse reactions and complications, patient satisfaction, and procedural difficulty score. RESULTS: The first-attempt success rate (80.7% vs 52.6%; 95% confidence interval [CI], for the difference, 11.6-44.6) and first-pass success rate (63.2% vs 31.6%; 95% CI for the difference, 14.2-49) were both significantly higher in the USAS compared with the USRTG group (both P = .001). The number of attempts (1 [1-1] vs 1 [1-3]; P = .001) and median passes (1 vs 3; P < .001) were both significantly lower in the USAS group than in the USRTG group. The USRTG group had a shorter locating time (175 seconds [129-234 seconds] vs 315 seconds [250-390 seconds]; P < .001) but a longer procedure time (488 seconds [260-972 seconds] vs 200 seconds [127-328 seconds]; P < .001) and total time (694 seconds [421-1133 seconds] vs 540 seconds [432-641 seconds]; P = .036). There were no significant differences between the 2 groups with regard to the adverse reactions and complications. More patients in the USAS group had a high satisfaction score of 3 to 5 (P = .008). Overall, anesthesiologists rated the USRTG group procedure as "more difficult" (P = .008). CONCLUSIONS: In elderly patients with hip fractures, spinal anesthesia with the USRTG technique is not superior to the USAS technique since it has a lower success rate, longer procedure time, lower satisfaction score, and is more difficult to perform. So USAS technique may be more suitable for elderly patients.

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.

Ultrasound-directed reduction of distal radius fractures in adults: a systematic review.

OBJECTIVE: To conduct a systematic review of the clinical literature to determine whether ultrasound can be used to improve the reduction of distal radius fractures in adults in the ED. METHODOLOGY: A study protocol was registered on PROSPERO. EMBASE, PubMed/MEDLINE, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov of the US National Library of Medicine were searched for studies evaluating ultrasound-assisted distal radial fracture reductions in comparison with standard care. The primary outcome of interest was manipulation success rates, defined as the proportion of fracture manipulations resulting in acceptable anatomical alignment, with secondary outcome being subsequent surgical intervention rates in ultrasound and standard care group of patients. RESULTS: 248 were screened at title and abstract, and 10 studies were included for a narrative synthesis. The quality of this evidence is limited but suggests ultrasound is accurate in determining distal radius fracture reduction and may improve the quality of reduction compared with standard care. However, there is insufficient evidence to determine whether this affects the rate of subsequent surgical intervention or functional outcome. CONCLUSION: There is a lack of evidence that using ultrasound in the closed reduction of distal radius fractures benefits patients. Properly conducted randomised controlled trials with patient-orientated outcomes are crucial to investigate this technology.

Ultrasonic actuation of a fine-needle improves biopsy yield.

Despite the ubiquitous use over the past 150 years, the functions of the current medical needle are facilitated only by mechanical shear and cutting by the needle tip, i.e. the lancet. In this study, we demonstrate how nonlinear ultrasonics (NLU) extends the functionality of the medical needle far beyond its present capability. The NLU actions were found to be localized to the proximity of the needle tip, the SonoLancet, but the effects extend to several millimeters from the physical needle boundary. The observed nonlinear phenomena, transient cavitation, fluid streams, translation of micro- and nanoparticles and atomization, were quantitatively characterized. In the fine-needle biopsy application, the SonoLancet contributed to obtaining tissue cores with an increase in tissue yield by 3-6× in different tissue types compared to conventional needle biopsy technique using the same 21G needle. In conclusion, the SonoLancet could be of interest to several other medical applications, including drug or gene delivery, cell modulation, and minimally invasive surgical procedures.

Diagnostic and procedural intraoperative ultrasound: technique, tips and tricks for optimizing results.

Intraoperative ultrasound (IOUS) is a valuable adjunctive tool that can provide real-time diagnostic information in surgery that has the potential to alter patient management and decrease complications. Lesion localization, characterization and staging can be performed, as well as surveying for additional lesions and metastatic disease. IOUS is commonly used in the liver for hepatic metastatic disease and hepatocellular carcinoma, in the pancreas for neuroendocrine tumors, and in the kidney for renal cell carcinoma. IOUS allows real-time evaluation of vascular patency and perfusion in organ transplantation and allows for early intervention for anastomotic complications. It can also be used to guide intraoperative procedures such as biopsy, fiducial placement, radiation, or ablation. A variety of adjuncts including microbubble contrast and elastography may provide additional information at IOUS. It is important for the radiologist to be familiar with the available equipment, common clinical indications, technique, relevant anatomy and intraoperative imaging appearance to optimize performance of this valuable imaging modality.

Ultrasonographically guided percutaneous transhepatic liver biopsy after pediatric liver transplantation.

BACKGROUND: Complications associated with ultrasonographically guided percutaneous transhepatic liver biopsy (PTLB) after liver transplantation (LT) have been rarely reported, and there is no consensus about its safety. We retrospectively reviewed the safety and outcomes of PTLB after pediatric LT. METHODS: Between January 2008 and December 2019, 8/1122 (0.71%) pediatric patients who underwent ultrasonographically guided PTLB after LT developed complications. The median age at PTLB was 7.8 years (range 0.1-17.9). Grafts included left lobe/left lateral segment in 1050 patients and others in 72. PTLB was performed using local anesthesia±sedation in 1028 patients and general anesthesia in 94. RESULTS: Complications after PTLB included acute cholangitis in 3 patients, sepsis in 2, respiratory failure due to over-sedation in 1, subcapsular hematoma in 1, and intrahepatic arterioportal fistula in 1. The incidence of complications of PTLB in patients with biopsy alone and those with simultaneous interventions was 0.49% and 3.19%, respectively (p = .023). Patients who developed acute cholangitis, respiratory failure, subcapsular hematoma, and arterioportal fistula improved with non-operative management. Of two patients with sepsis, one underwent PTLB and percutaneous transhepatic portal vein balloon dilatation and developed fever and seizures the following day. Sepsis was treated with antibiotic therapy. Another patient who underwent PTLB and exchange of percutaneous transhepatic biliary drainage catheter developed fever and impaired consciousness immediately. Sepsis was treated with antibiotic therapy, mechanical ventilation, and continuous hemofiltration. CONCLUSIONS: Percutaneous transhepatic liver biopsy after pediatric LT is safe. However, combining liver biopsy with simultaneous procedures for vascular and biliary complications is associated with an increased risk of complications.

Safety and efficacy outcomes of the Pioneer Plus catheter in endovascular revascularization of lower extremity chronic total occlusions.

OBJECTIVE: Our aim was to evaluate the efficacy and safety outcomes of the Pioneer Plus catheter (Philips, San Diego, Calif) and report the in-hospital and 30-day outcomes of lower extremity chronic total occlusion (CTO) interventions assisted by the Pioneer Plus catheter. In addition, we explored the factors associated with procedural success. METHODS: We conducted a retrospective review of 135 consecutive procedures in 116 patients from July 2011 to September 2018 performed by eight operators with various levels of experience at a high-volume center where the Pioneer Plus catheter was used for lower extremity CTO. The patient demographics, preprocedural symptoms, preprocedural testing results, procedural setting, and angiography findings were abstracted. The outcomes were divided into device-related and procedure-related outcomes. Device-related efficacy outcome included procedural success. Device-related safety outcomes included device-related complications. Procedure-related outcomes included procedure-related complications, 30-day major adverse cardiovascular events, and 30-day major adverse limb events. We conducted univariate comparisons of the provider, patient, and procedural characteristics stratified by procedural success. RESULTS: Procedural success was observed in 118 procedures overall (87.4%), and success rates ≤95.8% were observed for operators with an experience level of >25 devices deployed. No device-related complications, such as pseudoaneurysm formation, vessel perforation, or arteriovenous fistula formation, were observed. The Pioneer Plus catheter was mostly often used for CTO in the superficial femoral and popliteal arteries. Overall, the procedure-related complications included access site hematoma (5.2%), major bleeding (0.7%), pseudoaneurysm formation (0.7%), distal embolization (1.5%), and acute arterial thrombosis (1.5%). The 30-day major adverse limb events included index limb unplanned amputation (0.7%), index limb reintervention (4.4%), and index limb acute limb ischemia (0.7%) and occurred in 5.9% of the procedures. The only factor associated with procedural success was operator experience (P < .0001). CONCLUSIONS: The results from the present study have shown that Pioneer Plus catheter use is safe and effective when used to cross lower extremity CTO. However, further investigation is needed to identify patient- and provider-level factors to optimize patient outcomes.

Increased Needle Visibility in Ultrasound-Guided Percutaneous Liver Biopsy by an Echogenic Sheath: A Proof of Concept Study in a Human Cadaver.

PURPOSE: For the safety and success of an ultrasound-guided percutaneous liver biopsy, needle visibility and needle tip identification are critical. The aim of this pilot study was to evaluate the influence of an innovative echogenic sheath placed over a standard biopsy needle on needle visibility in ultrasound imaging. MATERIALS AND METHODS: Ultrasound videos of three sheaths with different coating characteristics (echogenicity) and one conventional liver biopsy needle were recorded at two angles (30° and 60°) and two depths (5 and 10 cm) in a human cadaver. The videos were blinded for needle type and presented to five independent radiologists who used Likert-scale scoring to rank each video for six characteristics on needle visibility. In addition, a phantom model was used to acquire standardized images for quantitative evaluation of the ultrasound visibility. Comparative statistical analysis consisted of a one-way ANOVA. RESULTS: The three prototype sheaths were ranked higher than the control needle at 60° with 5 cm depth, with an equal performance for the other conditions. The radiologists expressed more confidence in taking a biopsy with the echogenic sheaths than with the control needle, with 1 Likert score difference at 30°. Contrast analysis in the phantom model showed a statistically significant effect of a sheath (p = 0.004) on echogenic intensity. CONCLUSION: This pilot study suggests that the use of an echogenic sheath may increase needle visibility, particularly for trajectories requiring steeper insertion angles. To investigate the superiority of the echogenic sheath over conventional needles, a clinical study is necessary.

Ultrasound-guided needle insertion robotic system for percutaneous puncture.

PURPOSE: Ultrasound (US)-guided percutaneous puncture technology can realize real-time, minimally invasive interventional therapy without radiation. The location accuracy of the puncture needle directly determines the precision and safety of the operation. It is a challenge for novices and young surgeons to perform a free-hand puncture guided by the ultrasound images to achieve the desired accuracy. This work aims to develop a robotic system to assist surgeons to perform percutaneous punctures with high precision. METHODS: An US-guided puncture robot was designed to allow the mounting and control of the needle to achieve localization and insertion. The US probe fitted within the puncture robot was held by a passive arm. Moreover, the puncture robot was calibrated with a novel calibration method to achieve coordinate transformation between the robot and the US image. The system allowed the operators to plan the puncture target and puncture path on US images, and the robot performed needle insertion automatically. Five groups of puncture experiments were performed to verify the validity and accuracy of the proposed robotic system. RESULTS: Assisted by the robotic system, the positioning and orientation accuracies of the needle insertion were 0.9 ± 0.29 mm and 0.76 ± 0.34°, respectively. These are improved compared with the results obtained with the free-hand puncture (1.82 ± 0.51 mm and 2.79 ± 1.32°, respectively). Moreover, the proposed robotic system can reduce the operation time and number of needle insertions (14.28 ± 3.21 s and one needle insertion, respectively), compared with the free-hand puncture (25.14 ± 6.09 s and 1.96 ± 0.68 needle insertions, respectively). CONCLUSION: A robotic system for percutaneous puncture guided by US images was developed and demonstrated. The experimental results indicate that the proposed system is accurate and feasible. It can assist novices and young surgeons to perform the puncture operation with increased accuracy.

A novel electromagnetic guidance ultrasound system on radial artery cannulation: a prospective randomized controlled trial.

BACKGROUND: Radial artery cannulation can cause complications such as haematoma formation or thrombosis due to its small diameter. Recently, a novel ultrasound device equipped with an electromagnetic guidance system was introduced, showing the path and alignment of the needle during the procedure. The aim of this study was to investigate the effects of this novel system on both success and complication rates during radial artery cannulation under ultrasound guidance. METHODS: In this randomized controlled trial, 76 adults scheduled for neurosurgery requiring radial artery cannulation were recruited. In group E (n = 38), radial artery cannulation was performed using the electromagnetic guidance ultrasound system, whereas in group C (n = 38), the procedure was performed using conventional ultrasound guidance. The success rates of cannulation on the first attempt, cannulation times, number of attempts, and incidence of complications were compared between the two groups. RESULTS: There was a significant difference in the success rates on the first attempt between the two groups (group C = 78.9% vs. group E = 94.7%, P = 0.042). Incidences of posterior wall puncture and haematoma formation (group C = 8 vs. group E = 1; P = 0.028) were significantly lower in group E than in group C. The median cannulation time for successful attempts was comparable between groups. CONCLUSIONS: Use of the novel electromagnetic guidance system resulted in a better success rate on the first attempt and a lower incidence of complications during radial artery cannulation. TRIAL REGISTRATION: This study was registered at http://cris.nih.go.kr (registration number: KCT0002476 ).

Ultrasound-Guided Regional Anesthesia Using a Head-Mounted Video Display: A Randomized Clinical Study.

BACKGROUND: Ultrasonography is increasingly being used in every field of medicine, especially regional anesthesia. To successfully perform the procedure, a knowledge of anatomy and ultrasonoanatomy as well as technical 3D hand-eye coordination skills are required. Medical practitioners who use ultrasound devices to perform regional blocks have to correlate the position of the ultrasound probe on the patient, needle position, and ultrasound picture. To achieve that, the practitioner has to intermittently look between the patient and the ultrasonography screen. This requires extra head rotations, increasing the time and complexity of the procedure. Newer technologies are available that can alleviate the need for these extra head movements, such as head-mounted displays (HMDs), which are connected to the ultrasonography machine and project the ultrasonography picture onto the HMD goggles so that the provider can see the monitor without unnecessary head rotations. OBJECTIVE: Our theory was that the use of the HMD goggles would decrease the overall procedure duration as well as provider head rotations. STUDY DESIGN: This was a randomized clinical study. SETTING: The research was conducted at an academic medical center at the University of Texas Medical Branch, Galveston, TX. METHODS: We secured Institutional Review Board (IRB) approval to perform the study. We chose an HMD, which can be mounted on the head like regular goggles. By connecting the HMD with the ultrasonography machine, the ultrasound picture can be projected directly in front of the physician's eyes. Twenty-four patients were randomized to receive a regional anesthetic performed by anesthesiology residents using a conventional ultrasound-guided approach or using the HMD in addition. We measured the number of attempts, head rotations, and time needed to obtain a satisfactory nerve stimulation in addition to outcomes and adverse effects. Our data were interpreted by our statistician with P < .05 indicating statistical significance. RESULTS: Regional anesthetics performed with the HMD were significantly faster (59.08 vs 175.08 seconds) with significantly fewer head movements (0.83 vs 4.75) and attempts (1 vs 1.42). There were no significant differences in patient demographics, type of regional anesthetic, level of resident training, or outcomes. No complications were noted. LIMITATIONS: A limitation of our research is that neither observers nor providers were blinded to the way blocks were performed. This would have been practically impossible because participants had to wear an HMD. CONCLUSIONS: The HMD could provide advantages in regional anesthesia by decreasing the time and attempts and improving ergonomics. These findings can be easily translated into other ultrasound- or optic/camera-guided procedures outside of regional anesthesia, such as vascular access or laparoscopic surgery.IRB: UTMB IRB #12-143.

The Ability to Look: Management of Breast Disease in the Democratic Republic of the Congo Using Smart Ultrasound Technology.

BACKGROUND: The vast majority of women with breast cancer in sub-Saharan Africa present with advanced stage disease, due primarily to the lack of opportunities for early detection and treatment. As part of a larger effort to increase access to diagnostic and therapeutic services for women's cancers in the Democratic Republic of Congo (DRC), we implemented a curriculum to train the local workforce and a program to build the supportive infrastructure for the diagnosis and treatment of breast cancer at a private sector health facility (Biamba Marie Mutombo Hospital) in Kinshasa. STUDY DESIGN: After onsite trainings in the DRC by a US breast surgeon (RT), Congolese surgeons, general physicians, physician assistants, and nurses used the Phillips Lumify smart-phone ultrasound device to perform and interpret the results of whole breast ultrasound on symptomatic women. Surgeons were trained to perform ultrasound-guided core needle biopsy on those who met the criteria for tissue diagnosis, after which they trained nurses to do the same. RESULTS: Over 3 years, 5,211 patients were identified as having a breast abnormality on clinical breast examination. Ultrasound abnormalities were noted in 1,493 (27%) patients, of which 632 (42%) met the criteria for ultrasound-guided core needle biopsy or fine needle aspiration. Pathology reports were available on 368 (58%) patients who underwent biopsy, of which 164 were malignant and 204 benign. CONCLUSIONS: We demonstrated how the "ability to look" using smart technology can be successfully used to augment clinical breast exam and triage patients for biopsy in a resource-constrained African setting.

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.

Alternative vascular device for high-flow computed tomography angiography: ultrasound-guided long peripheral catheter (4 Fr × 10 cm).

INTRODUCTION: Radiological studies that require contrast media are common and useful in the emergency department. Alternatives have been proposed for the administration of contrast agent in patients with difficulty in the insertion of vascular access. Since 2017, our institution has used a 4-Fr × 10-cm-long peripheral catheter (Leadercath; Vygon) for venous insertion. Its ultrasound-guided insertion is carried out by emergency physicians. So far, there are no reports in the literature about the use of this long peripheral catheter for computed tomography angiography. OBJECTIVE: To describe the experience with the said device, to point out the complications associated with it, and to evaluate it as an alternative way to gain vascular access for patients with limited venous access. METHODS: An observational, analytical, and retrospective study was conducted. The study included patients who received an ultrasound-guided 4-Fr × 10-cm-long peripheral catheter (Leadercath; Vygon). Transparent, radiopaque, polyethylene, 18-gauge Leadercath from Vygon, sold as peripheral arterial catheter and sometimes used "off-label" as venous catheter with a flow capacity of up to 24 mL/min, was used. The flow capacity for gravity flow is 24 mL/s; with pump-driven flow, we achieved a flow infusion of 5-6 mL/s. Univariate analyses were performed. Normality was determined through the Shapiro-Wilk test. RESULTS: In total, 172 patients met the inclusion criteria. Of them, 115 (67%) were female and the average age was 59 years. The main indication for performing the computed tomography angiography was the suspicion of pulmonary embolism (38.6%). The most frequent type of computed tomography angiography study was pulmonary tomography (88 patients, 51.5%). The contrast medium infusion rate was 6 mL/s in 51.5% (n = 88) of cases, 4.5 mL/s in 36.3%, and 5 mL/s in 12.3%. One adverse event occurred. CONCLUSION: An 18-gauge-long peripheral catheter (4 Fr × 10 cm, Leadercath; Vygon) following specific protocols appears to be safe for conducting high-flow computed tomography studies in patients with limited venous access.