Shyam Varadarajulu

10.1055/a-2800-4292 On the eve of the 16th International Symposium on Endoscopic Ultrasonography (EUS) in San Francisco in 2008, a working group of 20 international experts convened to chart a roadmap for interventional EUS, a discipline then in its infancy [1]. Among the group’s key recommendations was the development of dedicated devices to facilitate EUS-guided drainage of pancreatic fluid collections (PFCs). In response, Xlumena Inc. developed the cautery-enhanced AXIOS lumen-apposing metal stent (LAMS) and delivery system [2]. Following Xlumena’s acquisition by Boston Scientific Corporation in 2015, the clinical footprint of the AXIOS stent expanded beyond PFC drainage to include gallbladder drainage for symptomatic acute cholecystitis. Subsequently, and largely off-label, the stent has been adopted for an increasingly broad range of complex interventions, including palliation of malignant distal biliary obstruction, creation of a gastroenterostomy in gastric outlet obstruction, and EUS-directed transgastric endoscopic retrograde cholangiopancreatography (EDGE) in patients with Roux-en-Y gastric bypass [3]. As with many transformative medical devices, this expansion has been accompanied by a series of “red flag” signals, each prompting incremental clinical or technical adaptations. The first such signal was reported by our group in 2016, during a randomized trial comparing the AXIOS with double-pigtail plastic stents for PFC drainage [4]. Prolonged LAMS indwelling, beyond 3–4 weeks, was associated with bleeding due to mechanical friction against adjacent vasculature, which led to recommendations for early LAMS removal or exchange to plastic stents. Subsequent challenges emerged with biliary applications, where stent dysfunction prompted the adjunctive placement of double-pigtail plastic stents to optimize axis orientation [5]. Perforation has also been reported when the stent is deployed in nondilated bile ducts (<15 mm), reflecting limitations in deployment distance – an issue that remains unresolved. More recently, the FDA approved the AXIOS stent for gallbladder drainage; however, we previously raised concerns regarding subsequent cholecystectomy, where the presence of a transmural fistula may compromise minimally invasive surgical approaches [6]. Food impaction of the gallbladder has also been described, managed – often suboptimally – by the placement of plastic stents or by exchanging the LAMS altogether. The AXIOS stent has now entered the domain of EUS-guided gastroenterostomy for malignant gastric outlet obstruction [3], where reports of perforation, particularly in the setting of ascites, have driven the development of anchoring balloons to enhance safety. Similarly, spontaneous stent migration during EDGE procedures has necessitated anchoring strategies using sutures or clips. The persistence of transmural fistulas after stent removal, with the attendant risk of weight gain, is a concern that remains unaddressed. In this issue of the journal, Vanella and colleagues report 12 cases of intraprocedural failure of distal flange deployment [7]. To address this, they advocate rhythmic amplitude traction, rather than continuous retraction, at the deployment hub. The authors hypothesize that this oscillatory motion induces microretraction of the sheath at the catheter tip, facilitating distal flange release. This rescue maneuver is clinically important, particularly in critically ill patients undergoing high risk interventions, where procedural failure may have grave consequences. Recently, the failure of distal flange deployment has resulted in three deaths during EUS-guided gastrojejunostomy and EDGE procedures. These adverse events have led the manufacturer to suspend the use of its 6-, 8-, and 20-mm Hot AXIOS stents [8]. While the precise mechanism leading to this issue remains uncertain, potential explanations include excessive adherence between the stent and overlying sheath or incomplete transmission of hub movement to the distal catheter tip. In my own practice, technical failures have occurred when acute angulation of the echoendoscope prevented device deployment into the target lumen ([Fig. 1]). Even during routine PFC drainage, distal flange release has occasionally failed, with successful deployment achieved only after a catheter “zigzag” manipulation, as described by Vanella et al. Some indications are however much riskier than undertaking PFC drainage. What lessons emerge from this evolving experience? The AXIOS stent was designed specifically for drainage of inflammatory fluid collections. Its core design – aside from dimensional variations – is now being applied to a growing spectrum of technically demanding and biologically distinct indications. Predictably, each new application has revealed new limitations, addressed not by redesign but by successive “sticking plaster” solutions ([Fig. 2]). These off-label uses carry a liability for physicians and institutions and, more importantly, may expose patients to avoidable harm. The broader lesson is clear: no single device can – or should – be expected to meet the diverse and expanding needs of therapeutic EUS. When we attempt to stretch a device beyond its original purpose, problems surface, some of which are consequential. Progress in interventional endoscopy will require the thoughtful redesign of existing platforms and development of purpose-built devices, rather than continued reliance on improvisation. Doing the latter can result in irreparable harm. Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Background Although surgical gastrojejunostomy (SGJ) is the standard method for palliation of gastric outlet obstruction (GOO), an endoscopic method—endoscopic ultrasound-guided gastroenterostomy (EUS-GE)—has been proposed as a novel, less invasive approach. Objective We compared both methods to determine whether clinical outcomes for EUS-GE are superior to surgery. Design We conducted a multicentre, randomised superiority trial of patients with malignant GOO to receive either EUS-GE or SGJ. Primary endpoint was composite measure, consisting of Gastric Outlet Obstruction Scoring System (GOOSS) score of 0 or 1 at hospital discharge, need for reinterventions or supplemental nutrition, or procedure-related adverse events during 6-month follow-up or until death. Secondary endpoints were time to solid diet, length of hospitalisation, health-related quality of life (HRQoL) and treatment costs. Results 74 patients were randomly assigned to EUS-GE (38 patients) or SGJ (36 patients). Primary endpoint occurred in 7.9% of patients who received EUS-GE and 38.9% in SGJ (risk difference −31.0%, 95% CI −47.6% to −11.4%, p=0.002). EUS-GE was associated with more rapid advancement to solid diet (median 2 days (P25–P75, 2–3) vs 5 days (P25–P75, 3.5–9)), shorter hospitalisation (median 3 days (P25–P75, 3–6) vs 9 days (P25–P75, 6–12.5)), better HRQoL for physical (p=0.0016) and social functioning (p=0.011) and lower treatment costs (US$33 934 vs US$51 437, difference −US$17 503 (95% CI −US$27 807 to −US$7920)). Conclusion In this randomised trial, EUS-GE was superior to SGJ with regards to oral intake, need for reinterventions or supplemental nutrition, length of hospitalisation, quality of life and treatment costs. Trial registration number NCT05548114.

Endoscopic ultrasonography (EUS) is the most sensitive modality for accurately establishing a tissue diagnosis in patients with solid pancreatic masses. However, small lesions can be challenging to detect, particularly for less experienced endosonographers. Therefore, outcomes of EUS are operator dependent. We validated the performance of novel artificial intelligence (AI)-enhanced EUS for detection of solid pancreatic lesions. In this single-center, prospective, nonrandomized, comparative study, high-risk patients aged ≥18 years referred for pancreatic cancer screening or with suspected (solid and cystic) pancreatic lesions owing to symptoms, radiological, or laboratory findings were evaluated in real time using AI-EUS software. The model included 32 713 EUS frames (training/testing phases) of normal, solid, and >10-mm cystic pancreatic lesions from 202 patients. Clinical validation was conducted prospectively when EUS findings were evaluated concurrently in real time by two independent expert examiners, one using conventional EUS and another with AI-EUS, both blinded to the alternative assessments. The primary outcome was detection of solid pancreatic masses. 308 patients were evaluated (January–July 2024). AI-EUS performance was not significantly different to that of conventional EUS performed by experts (97.1% vs. 100%; risk difference 2.9%, 95%CI –1.2 to 6.8; P = 0.25). Final pathology of 105 pancreatic solid masses revealed neoplasia in 93 (88.6%) and benign lesions in 12 (11.4%). The performance of AI-EUS was not significantly different to that of experienced endosonographers for detection and segmentation of solid pancreatic masses. By standardizing performance, AI-EUS may have the potential to optimize clinical outcomes in pancreatic cancer.

Endoscopic ultrasound (EUS) has been suggested as the primary modality in lieu of endoscopic retrograde cholangiopancreatography (ERCP) for drainage of malignant distal biliary obstruction. However, the presence of a dilated bile duct (≥12 mm) is a prerequisite for the success of the EUS approach. In a retrospective study, we found that 44.9% of 439 ERCP patients over a 3-year period had insufficiently dilated bile duct that was not conducive for an EUS-based intervention. 29 patients were treated by a salvage EUS approach, with median bile duct diameter of 16 mm (IQR 13–18 mm). Although indispensable as a rescue technique, adopting current techniques and technology, this study does not suggest a universal primary role for EUS in this setting.

Lumen-apposing metal stents (LAMSs) are being increasingly used for the drainage of walled-off necrosis (WON). It was postulated that their placement, compared with plastic stents, is technically easier, decreases the need for necrosectomy, lowers adverse events, enables faster disease resolution, and is potentially more cost effective. However, with the exception of shorter procedural duration, other perceived advantages have not been borne out in randomized trials [1]. In this issue of Endoscopy, Moon et al. from South Korea compare the performance of a 16-mm novel electrocautery-enhanced LAMS (Niti-S HOT SPAXUS stent; Taewoong Medical, Goyang, South Korea) with that of 7-Fr plastic stents [2]. The study cohort comprised 46 patients with infected WON and the main outcome measure was number of necrosectomy procedures required to achieve clinical success. As observed in prior randomized trials, there was no difference in the primary outcome between study cohorts [3] [4] [5]. However, while there was no difference in clinical success, which was defined as partial or complete resolution of WON in conjunction with symptom resolution at 4 weeks, there was significant difference in favor of LAMS at 8 weeks. There are several aspects worth contemplating while reviewing the findings of the present study. First, while a 16-mm-diameter endoprosthesis was chosen for the LAMS cohort, in the plastic stent cohort, the transmural tract was accessed with a 6-Fr cystotome and dilated to only 4–6 mm before one or two 7-Fr endoprostheses were placed. The standard of care when treating pancreatic fluid collections using plastic stents is to perform 12–15-mm transmural tract dilation and place a minimum of 2–3 stents. In a recent report that compared outcomes between LAMS and plastic stents in 303 patients with pancreatic fluid collections, it was reported that placement of two 7-Fr plastic stents (after transmural tract dilation to 12–15 mm) was associated with a higher proportion of organ failure and systemic inflammatory response at 48 hours, particularly in patients with greater than 33% necrosis [6]. Second, while the median degree of necrosis in the present study was reported to be 70% or more in both groups, disconnected pancreatic duct syndrome (DPDS) was observed in less than 5% of the study cohort. In a prior randomized trial comparing endoscopy and minimally invasive surgery for treatment of necrotizing pancreatitis, it was observed that a median of 40% necrosis was associated with DPDS in more than 80% of patients [7]. Similarly, DPDS was observed in 41.9%–51.8% of patients who received LAMS or plastic stents in two recent randomized trials [3] [5]. It is important to note that the degree of necrosis was still significantly less in both those clinical trials compared with the present study. Third, in the present study, endoscopic necrosectomy was performed in 13.0% of plastic stent and 21.7% of LAMS cohorts compared with a pooled estimate mean of 38.5% for LAMS (95%CI 10.5–71.6) and 41.2% (95%CI 22.0–61.9) for plastic stent cohorts in the meta-analysis of three randomized trials [1]. Fourth, clinical success in two prior randomized trials was defined as complete resolution of WON in conjunction with symptom relief, whereas in the present study it was defined as reduction in size of the necrotic collection to more than 50% at 4 weeks accompanied by symptom relief. Finally, outcomes in WON can be ascertained reliably only when the follow-up duration is adequate – usually 6 months after index hospital discharge. In the present study, clinical success was ascertained at 4 weeks post-procedure and final follow-up was conducted at 3 months. Cross-sectional imaging to ascertain the complete resolution of the disease process was not performed. While it may be reasonable to assume that both stents performed equally well in the present study, the probability that LAMS yielded higher clinical success at 8 weeks cannot be justified due to the serious, significant, limitations outlined above and the very small sample size of 46 patients. While randomized trials may be difficult to execute, the study design should still be rigorous, sample size adequately powered, and follow-up duration reasonably long to capture all relevant clinical end points. Otherwise, the study findings become difficult to interpret and it is left to the wisdom of the readers to search for those hidden pearls that may or may not meaningfully impact their clinical practice. Article published online: 07 August 2024 © 2024. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany