Background:Third-space endoscopy is standard practice for neoplastic and motility disorders; however, it carries a high risk of intraprocedural bleeding. Such risk may be reduced by prophylactic coagulation of submucosal vessels, but this requires instrument exchange. A new approach involves pre-sealing submucosal vessels under saline immersion using standard electrocautery settings and the same knife. Methods:Patients undergoing third-space procedures (endoscopic submucosal dissection or peroral endoscopic myotomy) were randomized to receive either targeted saline-immersion pre-sealing (intervention group) or conventional coagulation (carbon dioxide insufflation, control group) for prophylactic management of vessels ≥1.2 mm. Dissection settings were identical. Rate of per-patient intraprocedural bleeding requiring re-treatment for vessels ≥1.2 mm was the main outcome. Per-vessel analyses were also performed. The use of an adjunctive device and coagulation time were also assessed. Results:70 patients (37 immersion, 33 control) with 864 ≥1.2-mm vessels were included. Saline-immersion pre-sealing significantly reduced bleeding rates: per patient (32.4% vs. 75.8%; relative risk [RR] 0.43, 95%CI 0.26-0.71; number needed to treat [NNT] 2.3; P < 0.01); per vessel (6.3% vs. 29.9%; RR 0.21, 95%CI 0.14-0.31; NNT 4.2; P < 0.01). Use of coagulation forceps for bleeding treatment also decreased (0% vs. 24.2% and 0% vs. 8.3%; P < 0.01). A significant reduction in mean (SD) coagulation time was reported in the saline-immersion group (22.7 [26.4] vs. 29.6 [49.8] seconds; P < 0.01). Conclusions:A substantial reduction in the risk of intraprocedural bleeding was achieved by saline-immersion pre-sealing in per-patient and per-vessel analyses, prompting its implementation in clinical practice.

Saline-immersion therapeutic endoscopy (SITE) enhances visualization and haemostasis, but it alters electrosurgical behavior due to the high conductivity of saline which reduces tissue impedance and peak voltage. These effects may vary depending on the knife size, as electrode diameter influences current density. An ex vivo porcine gastric mucosa model was used to compare three electrosurgical knives with different sizes, namely one with a thick electrode (HybridKnife® T-Type, 1.5 mm) and two with thin electrodes (HYBRIDKnife® flex I-Type, 0.5 mm; DualKnife J-Type, 0.4 mm) - in air and under saline across seven electrosurgical modes (2 cutting, 3 coagulation and 2 dissection modes). Electrical parameters (impedance, peak voltage, power output), cutting success, and lateral thermal spread were measured during 252 standardized incisions. Statistical analysis was performed using both univariate and multivariate methods. The average decrease in impedance when passing from air to saline immersion was higher for thick as compared with thin knives (92% vs. 55%, p < 0.001) across multiple modes. Corresponding increase in power was also higher for thick (up to 19-fold) than for thin (up to 5-fold, p < 0.001) knives, while peak voltage decreased by 30% for thick knives and increased by approximately 2% for thin knives (p < 0.001). Across cutting and dissection modes, both thin knives sustained 100% cutting success in air and under saline, whereas the thick knife declined from 100% to 75% under saline. Lateral thermal spread increased from < 1 mm in CO2 to 1.35 mm (256%) in saline for the thick knife, while it was ≤ 0.8 mm (71%) for thin knives (p < 0.001, between thin and thick knives), irrespective of the setting. Electrode diameter and saline immersion were the strongest independent predictors of lateral spread. The effect of saline immersion on impedance and voltage is dramatically higher when using thicker than thinner knives This may contribute to the differing tissue effects observed with varying electrode sizes in third-space endoscopy.

Background:The rise of antibiotic-resistant bacteria is a major public health concern. Physical plasma can generate reactive oxygen and nitrogen species (RONS) with antimicrobial activity. Plasma-activated liquid (PAL) can be used as a carrier for RONS. This study investigated the antibacterial effects of PAL against clinically relevant Gram-negative (Escherichia coli, multidrug-resistant (MDR) Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Klebsiella pneumoniae, and Helicobacter pylori) and Gram-positive (Staphylococcus aureus and Enterococcus faecium) bacteria. Methods and results:A commercial argon plasma electrosurgical source was used to produce PAL from 0.9% NaCl solution. PAL-NaCl showed strong bactericidal effects: MDR E. coli was completely eradicated (>6 log10 reduction) within 60 min. H. pylori was reduced by ~4.5 log10 within 15 min and completely eradicated (>5 log10) within 60 min of exposure. Gram-negative bacteria were highly susceptible with a mean reduction of ~6.3 log10, whereas Gram-positive bacteria showed lower susceptibility with a mean reduction of ~2.6 log10. Antibacterial activity was associated with acidic pH and influenced by carrier solution chemistry, consistent with a contribution of short-lived secondary reactive nitrogen species. The scavenger 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinato iron(III) chloride (FeTPPS), targeting peroxynitrite (ONOO-), partially inhibited the antibacterial effect, supporting its mechanistic importance. Buffered solutions (higher pH) showed minimal antibacterial activity despite higher absolute RONS concentrations which underlines the importance of the acidic environment. Conclusion:PAL generated with an argon plasma electrosurgical source exhibits potent antibacterial activity, driven by low pH and RONS dynamics. PAL effectively inactivates MDR pathogens and other clinically relevant pathogens, including H. pylori. The stomach's acidic environment may enhance PAL activity by maintaining the low-pH conditions required for pH-dependent reactive nitrogen chemistry associated with antibacterial efficacy.

Intraoperative frozen section diagnostics remains the standard for surgical margin assessment in oncologic surgery but is limited by interobserver variability, restricted availability, and time constraints. Optical emission spectroscopy (OES), a label-free analytical technique, offers a potential alternative by utilizing emission spectra generated during radiofrequency (RF) ablation to distinguish normal from malignant tissues. In this ambispective, multicenter feasibility study, OES spectra were recorded from 137 liver specimens (fresh and cryopreserved) obtained from patients with cholangiocellular carcinoma (CCC) or colorectal liver metastases. Measurements were performed using two spectrometers (Maya 2000Pro and ESA 4000), and machine-learning models, including support vector machines (SVMs) and neural networks (NNs), were trained to classify spectra as normal or tumorous. Spectral analysis revealed consistent differences between normal and malignant liver tissue in emission lines corresponding to corresponding to Mg (279.6-285.2 nm), Na (330.2 nm), Ca (393.4 and 396.9 nm), and Zn (213.5 nm). Using these data, NNs outperformed SVMs across all subgroups, increasing accuracy from 76.9% to 87.8% for metastases and from 76.0% to 88.4% for CCC. Classification performance was consistent between participating cancer centers and unaffected by sample type (fresh vs. cryopreserved). Prediction accuracy remained independent of tumor cell proportion, suggesting that NNs captured information from both tumor cells and the surrounding microenvironment. OES enables rapid, accurate, and reproducible ex vivo differentiation between normal and malignant liver tissue. With further refinement and clinical validation, this approach could complement or, in selected cases, replace intraoperative frozen sections, particularly in time-critical or resource-limited surgical settings.

Cold atmospheric plasma (CAP) has emerged as a promising tool in biomedical applications, including the treatment of precancerous neoplasias. The clinical application of low-thermal argon plasma devitalization (ltAPD) using electrosurgical argon plasma coagulation (APC) probes demonstrated significant clinical efficacy in the treatment of cervical intraepithelial neoplasia (CIN) across several prospective clinical trials. Building on the previously demonstrated antineoplastic efficacy of ltAPD treatment, we investigated a prototype dielectric barrier discharge (DBD) plasma source as an alternative plasma generation principle for the treatment of larger areas under preclinical conditions. Both devices were characterized regarding their electrical properties, reactive oxygen and nitrogen species (RONS) generation, biological efficacy, and penetration depth. Electrical measurements revealed a significantly lower current and reduced energy output for the DBD compared to the clinically approved APC probe. Reactive species analysis demonstrated comparable hydrogen peroxide generation between both devices in argon atmospheres, while the APC probe generated higher levels of ·OH and NO2- in argon atmosphere. As the gas composition is defined entirely by the externally supplied mixture, the DBD allowed the working gas to be tuned systematically by adding small fractions of air (87.5% argon/12.5% air) which strongly enhanced nitrogen-species formation and biological efficacy. Implementation of nitrogen or air to the APC could likewise lead to an increase in nitrogen species. Ex vivo treatment of human cervical tissue displayed staining for the DNA damage marker γ-H2AX throughout the epithelial layer for both devices, without detectable structural tissue damage. Agarose gel experiments under controlled laboratory atmospheres revealed greater reactive species penetration depth for the APC probe, whereas the DBD prototype provided a larger treatment area. While DBD efficacy was demonstrated under defined laboratory gas conditions in a controlled chamber setup, these findings establish a first preclinical rationale for DBD as a complementary plasma geometry.

Background:Tissue diagnosis of biliary strictures is challenging and often requires multiple methods. Cryobiopsy, which is well established in bronchoscopy with high tissue yield, is presented here for the first time as a proof-of-principle feasibility study performed via the percutaneous route for biliary strictures. Methods:Patients undergoing percutaneous cholangioscopy for intraductal diagnosis of biliary strictures underwent six forceps biopsies and three cryobiopsies in a randomized order. The main objective was to assess feasibility, defined as the retrieval of at least one adequate sample per method per patient. Results:Among 15 patients (53% women; mean age 60.2 years), all had at least one adequate sample obtained by each method. Cryobiopsy yielded significantly larger (8.54 vs. 1.87 mm2; P < 0.001) and more representative specimens (97.6% vs. 74.7%; P = 0.001). It also scored higher on overall histologic quality on a Likert scale of 0–6 (5 vs. 4; P < 0.001) and had more artifact-free areas (93.5% vs. 85.5%; P = 0.01). No bleeding or perforations occurred; only minor adverse events were reported and these resolved with standard treatment. Conclusions:This feasibility study showed that intraductal cryobiopsy via percutaneous cholangioscopy yielded larger samples and may enable more detailed histologic assessment than forceps biopsies. Further studies will evaluate its accuracy, safety, and potential for use with peroral cholangioscopy during endoscopic retrograde cholangiopancreatography.

Impedance and voltage of monopolar currents are directly related. By replacing air with saline solution, a change in behavior of these currents are achieved in endoscopy, resulting in a desired coagulation effect. However, the underlying electrophysical mechanisms of this effect remain poorly explained. This investigation assessed the relationship between the electrical parameters and the surrounding environment for three high-voltage monopolar coagulation currents commonly used for therapeutic endoscopy. Six consecutive applications per setting and per environment were performed with dissection knife on porcine kidney. When transitioning from air to saline immersion, a 99% decrease in impedance was observed for all current settings tested (AirRange: 4400–8150 Ω, SalineRange: 64–71 Ω; p < 0.01 for all settings). This resulted in a 52-78% reduction in peak voltage (AirRange: 920–1165 V, SalineRange: 257–499 V; p < 0.01 for all settings), and a 237-2030% increase in power delivered (AirRange: 3–19 W, SalineRange: 50–117 W; p < 0.01 for all settings). The dramatic decrease in impedance results in a sharp reduction of voltage, explaining the coagulation effect observed when passing from air to saline-immersion therapeutic endoscopy.

Introduction:High-grade squamous intraepithelial lesions (HSIL), such as cervical intraepithelial neoplasia grade 3 (CIN3), are precursors to invasive cancer. Although cancer develops in only 1-2 out of 10 patients with CIN3, all patients typically undergo invasive procedures. This overtreatment affects approximately 90% of CIN3 patients, especially young women, posing risks to fertility and pregnancy outcomes. Non-invasive physical plasma (NIPP) treatment via low thermal argon plasma devitalization (APD) technology offers a novel, outpatient alternative with potential tissue-preserving and antineoplastic properties. Methods:This prospective, monocentric, randomized, controlled phase IIb trial (NCT04753073) evaluated the efficacy of APD in achieving histological remission of CIN3, compared to the natural course in an untreated control group. Forty premenopausal women aged 18 years or older with confirmed CIN3 were enrolled and randomized into two groups: 20 underwent a single APD treatment session followed by large loop excision of the transformation zone (LLETZ) 6-8 weeks later, and 20 served as untreated controls undergoing LLETZ only. Pain perception and patient satisfaction were assessed via visual analog scale and the Freiburg Index of Patient Satisfaction (FIPS), respectively. Statistical analyses included Fisher's exact tests and odds ratio (OR) calculations and were conducted using SPSS. Results:Complete histological remission of CIN3 was observed in 33.3% of APD-treated patients compared to 5.0% in the control group (p = 0.025, OR = 9.43). Partial remission occurred in 27.8% of APD patients and 15.0% of controls, while persistent CIN3 was more common in controls (80.0% vs. 38.9% in APD-treated patients). APD treatment also facilitated R0 resection during consecutive LLETZ in 94.4% of cases versus 65.0% in the control group (p = 0.082). No severe adverse events were reported, and patient satisfaction was comparable between groups. Conclusion:APD treatment demonstrates significant efficacy in inducing histological remission of CIN3, reducing lesion severity, and preserving tissue. This innovative approach offers a promising, minimally invasive alternative to conventional surgical methods, particularly for women of childbearing age. Given the current issue of overtreatment with invasive procedures, APD could significantly reduce unnecessary interventions. Larger, multicenter trials are warranted to confirm these findings and establish APD as a standard treatment for HSIL. Clinical trial registration:https://www.clinicaltrials.gov/study/NCT04753073, identifier NCT04753073.

Video 1Case description and video in cholangioscopic view demonstrating bile duct tissue acquisition by cholangioscopy-guided cryobiopsy technique.

Immunological consequences of endoscopic ultrasound (EUS)-local thermal ablation (LTA) for pancreatic ductal adenocarcinoma (PDAC) have not been extensively assessed. We aimed to explore EUS-LTA effects on the systemic immune response in PDAC. Peripheral blood was collected from 10 treatment-naïve patients with borderline resectable and locally advanced PDAC, randomly allocated to Nab-paclitaxel plus Gemcitabine chemotherapy (CT-arm, n = 5) or EUS-LTA with HybridTherm Probe plus CT (HTP + CT-arm, n = 5). Twenty healthy donors were included as controls. Flow-cytometry and multiplex assays were used to profile immune cell subsets and measure serum cytokines/chemokines, respectively. At baseline, PDAC patients showed increased circulating monocytes and lower circulating lymphocytes and CD19+ B cells counts compared to healthy controls. After 4 months, CT induced decrease of B regulatory cells, CD4+ cytotoxic T cells and IL-1β. The addition of EUS-HTP to CT selectively decreased the serum levels of APRIL/TNFSF13 as well as T regulatory cells, total, classic and inflammatory monocytes. Serum levels of APRIL/TNFSF13 and total, classic and inflammatory monocytes counts at baseline were associated with worse overall survival. EUS-HTP has the potential to selectively impact on immune cells and cytokines associated with poor outcomes in PDAC.

Background and Objectives: Data on the clinical efficacy of EUS-guided ablation using the HybridTherm-Probe (EUS-HTP) in locally advanced pancreatic ductal adenocarcinoma (LA-PDAC) are lacking. The aim of the study was to assess the impact of EUS-HTP added to chemotherapy (CT) on overall survival (OS) and progression-free survival (PFS) of LA-PDAC patients with local disease progression (DP) after first-line therapy, compared to CT alone in controls. Methods: LA-PDAC cases, prospectively treated by EUS-HTP, were retrospectively compared to matched controls (1:2) receiving standard treatment. Study endpoints were the OS and PFS from local DP after first-line therapy, compared through log-rank test calculating hazard ratios and differences in restricted mean OS/PFS time (RMOST/RMPFST) within prespecified time points (4, 6, and 12 months). Results: Thirteen cases and 26 controls were included. Clinical, tumor, and therapy features before and after first-line therapy were case–control balanced. The median OS and PFS were not significantly improved in cases over controls (months: 7 vs. 5 and 5 vs. 3, respectively). At 4 and 6 months, the RMPFST difference was in favor of cases (P = 0.0001 and P = 0.003, respectively). In cases and controls not candidate to further CT (N = 5 and N = 9), the median OS and PFS were not significantly improved in cases over controls (months: 6 vs. 3 and 4 vs. 2, respectively), but the RMPFST difference was in favor of cases at 4 months (P = 0.002). Conclusions: In locally progressive PDAC patients experiencing failure of first-line therapy, EUS-HTP achieves a significantly better RMPFST up to 6 months compared to standard treatment, although without a significant impact on OS.

Background and study aims  Indeterminate biliary strictures represent a major challenge in clinical diagnostics. Diagnostic yield of radiological, endoscopic imaging and histopathological diagnosis is insufficient. The cryobiopsy technique is a new method for tissue extraction already used in different clinical settings. The aim of this ex vivo clinical study was to investigate feasibility and tissue quality of cryobiopsy in the bile duct. Patients and methods  We included 14 patients who underwent pancreaticoduodenectomy. Bile duct samples were taken with either a new prototype cryoprobe or one of two forceps types. Results were analyzed for general feasibility, specimen size, histological assessability as well as representativity of retrieved tissue. Results  Feasibility of cholangioscopic forceps was poor compared to gastric biopsy forceps or cryobiopsy. Significantly larger tissue samples were obtained with cryobiopsy (5.6 ± 4.5 mm 2 ) compared to gastric biopsy forceps (3.3 ± 5.1 mm 2 , P  = 0.006). Furthermore, cryobiopsy was superior in histological assessment quality ( P  = 0.02) and concerning representativity ( P  = 0.03). Conclusions  Cryobiopsy in the bile duct is feasible and the quality of the obtained tissue is high. Further investigation of bile duct cryobiopsy in vivo is warranted.

(1) Background: Cervical intraepithelial neoplasia (CIN) of long-term persistence or associated with individual treatment indications often requires highly invasive treatments. These are associated with risks of bleeding, infertility, and pregnancy complications. For low- and middle-income countries (LMICs), standard treatment procedures are difficult to implement and manage. We characterized the application of the highly energized gas "noninvasive physical plasma" (NIPP) for tissue devitalization and the treatment of CIN. (2) Methods: We report the establishment of a promising tissue devitalization procedure by NIPP application. The procedure was characterized at the in vitro, ex vivo and in vivo levels. We performed the first prospective, single-armed phase-IIb trial in 20 CIN1/2 patients (NCT03218436). (3) Results: NIPP-treated cervical cancer cells used as dysplastic in vitro model exhibited significant cell growth retardation due to DNA damage, cell cycle arrest and apoptosis. Ex vivo and in vivo tissue assessments showed a highly noninvasive and tissue-preserving treatment procedure which induces transmucosal tissue devitalization. Twenty participants were treated with NIPP and attended a 24-week follow-up. Treatment success was achieved in 19 (95%) participants without postinterventional complications other than mild to moderate discomfort during application. (4) Conclusions: The results from this study preliminarily suggest that NIPP could be used for an effective and tissue-preserving treatment for CIN without the disadvantages of standard treatments. However, randomized controlled trials must confirm the efficacy and noninferiority of NIPP compared to standard treatments.