Conventional Catheter Research Articles

Magnetically-driven robotic microscrew for the oviduct recanalization

Blocked fallopian tubes, leading to tubal factor infertility, seriously affect fertility and pregnancy. The current mainstream surgical approach for tubal recanalization is based on conventional catheters and guidewires to clear the blockage. However, it is challenging to treat the distal tubal obstruction due to the large size of the tubal catheter and the poor steerability of the guidewire. Here, we present a magnetically driven robotic microscrew to clear blocked fallopian tubes based on a helical rotating mode. The microscale screw-shaped microrobot is fabricated by 3D microfabrication technology. The motion direction and speed of the microrobot are modulated by customizing the pattern and parameters of the control magnetic field. The microscrew structure generates mechanical force to drill the blockage, and then the destroyed fragments are transported to the tail of the robots via the vortex flow surrounding the microscrew. Finally, we demonstrate the recanalization effect of the proposed microrobot in the fallopian tube-mimicking phantom. The recanalizing microscrew represents a potential strategy for developing autonomous tools to treat the blockage of small lumens.

Short and long-term clinical results of a minimally invasive syringe adapter for catheter free instillation of intravesical treatments

Introduction:Intravesical treatment is currently dependent on catheterization which can cause urethral discomfort and risk of urinary tract infections in selected patient groups such as interstitial cystitis/bladder pain syndrome (IC/BPS), overactive bladder syndrome (OAB) and recurrent urinary tract infections (rUTI). This study describes real-life clinical experience of a minimally invasive syringe adapter (Ialudapter®) for catheter-free instillation of intravesical treatment. Methods:A retrospective study from a single center was performed. Quantitative and qualitative data was obtained on the use of the syringe adapter (IALUADAPTER®) in 61 patients with IC/BPS (n=48), rUTI (n=6) and mixed /other diagnoses (including OAB; n= 7) who were receiving intravesical therapy. The evaluation period was 6 months during 2018–2019. Reasons for trying the syringe adapter, reasons for continuing with it and occurrence of UTIs before and during the evaluation period were recorded. In addition, 3 year follow-up data were obtained to assess long-term usage of the syringe adapter. Results:Mean follow-up was 4 months. The use of the syringe adapter was successful in 75% and a positive experience in 74% with the latter continuing to use the syringe adapter. Long-term (>3 yrs) adherence of 40% was observed. The patients reported less pain (41%) while 23% reported that it was easier to use compared to conventional catheters. Only 6 UTIs were observed in the follow-up period. Discussion and conclusions:This retrospective study shows that the Ialudapter® is a good, safe alternative to conventional catheterization for intravesical treatment.

Comparison of conventional vs. fluoroless catheter ablation of supraventricular tachycardias

Comparison of conventional vs. fluoroless catheter ablation of supraventricular tachycardias

Efficacy and safety of pulmonary artery catheterization with combined transesophageal echocardiography and pressure waveform: A prospective observational study

ObjectiveThis study investigated whether pulmonary artery catheter placement method with combined transesophageal echocardiography and pressure waveform measurement improve the placement success rate within 5 min and reduce the incidence of arrhythmia during pulmonary artery catheter placement compared to conventional pulmonary artery catheter placement with pressure waveform measurement only. MethodsThis single center prospective observational study included 129 patients scheduled for cardiac surgery. Patients were divided into two groups. In the conventional group, the pulmonary artery catheter was placed by monitoring the pressure waveform and the length of placement; in the combination group, not only were the pressure waveform and the length monitored but also the following transesophageal echocardiography images: “mid esophageal bicaval view,” " mid esophageal modified bicaval view,” a mirror image of “mid esophageal 4 chamber view,” “mid esophageal right ventricular inflow-outflow view,” and “mid esophageal ascending aortic short axis view." ResultsA 1:1 propensity score matching was used to adjust for confounding factors. The success rates of pulmonary artery catheter placement within 5 min in the conventional and combination groups were 85.5 % vs. 97.8 % (p = 0.032) before matching, and 73.7 % vs. 100 % (p = 0.001) after matching. The incidences of arrhythmias in the conventional and combination groups were 28.9 % vs. 17.4 % (p = 0.20) before matching, and 28.9 % vs. 18.4 % (p = 0.42) after matching. ConclusionPulmonary artery catheter placement with transesophageal echocardiography had a significantly higher rate of successful placement within 5 min, but no significant differences were observed in the incidences of arrhythmias.

Efficacy of antimicrobial-impregnated catheters in preventing sepsis post epicutaneo-caval catheter (ECC) removal in neonates: A retrospective study.

Epicutaneo-caval catheters (ECC) are vital in neonatal intensive care units (NICU) in enabling prolonged venous access. Despite their benefits, central line-associated bloodstream infections (CLABSI) pose a potential risk. The ECC removal procedure may contribute to an increased risk of post removal sepsis through biofilm release. Antimicrobial-impregnated ECCs have been proposed as a potential solution to prevent this complication, but research on their effectiveness in neonates is limited. To compare post-ECC or neonatal peripherally inserted central catheter (n-PICCs) removal sepsis rates when using conventional or antimicrobial-impregnated catheters in neonates. A retrospective, single center cohort analysis using 2019 data from 421 neonates after successful ECC insertion at the Women's Wellness and Research Center, a large tertiary level NICU in Qatar. The study systematically collected data on demographics, insertion, and removal as well as microbiology, and infection data. Statistical analyses compared conventional and antimicrobial ECCs, with a focus on the incidence of sepsis within 72 hr post-removal. After excluding non-eligible, 349 cases were included in the analysis (138 conventional, 211 antimicrobial-impregnated). There were no significant demographic differences between the two groups. The CLABSI incidence was higher amongst the antimicrobial ECC group (4% vs 0.6%, p = 0.031). Among the included neonates, the confirmed post-removal sepsis incidence was 4.3% (6 cases) for the conventional and 10% (21 cases) for the antimicrobial ECC groups, which was not statistically significant (p = 0.055). The study noted a higher, but statistically insignificant, incidence of post removal sepsis when using antimicrobial-impregnated ECCs. This finding raises questions about the effectiveness of antimicrobial ECCs in preventing post-removal sepsis in this patient population. Further randomized trials are needed to assess the role of antimicrobial ECCs amongst neonates and to refine neonatal ECC care strategies.

New compact micro-hole zone catheter enables women to achieve effective bladder emptying without flow-stops.

Clean intermittent self-catheterisation (CISC) with conventional eyelet catheters (CECs) is associated with urine flow-stops, which require the catheter to be repositioned so flow can resume. Flow-stops often occur because bladder mucosa is sucked into the eyelets. This investigation aimed to compare the bladder-emptying performance of the micro-hole zone catheter (MHZC) with the CEC. This was a multi-centre, randomised, open-label, controlled cross-over study with 82 women comparing the MHZC to the CEC. The endpoints relating to bladder-emptying performance included the residual volume at first flow-stop, the number of flow-stops and the proportion of successful treatment responses. The women's perception of the catheters was assessed as well as device discomfort. Catheterisations with MHZC significantly reduced the risk of flow-stops, with relative risk results showing a 2.74 times lower risk of flow-stops with a health professional-led catheterisation and a 2.52 times lower risk during self-catheterisation. There was no statistical difference in residual urine volume at first flow-stop between the two catheters. Catheterisations with the MHZC were significantly more likely to achieve zero flow-stops and a residual urine volume of <10 ml at first flow-stop. The women had a significantly more positive perception of the MHZC than the CEC in areas including handling, confidence, sensation and satisfaction. The MHZC enabled effective bladder emptying without catheters needing to be repositioned, supporting the women by simplifying the procedure and making them feel confident that their bladders were empty.

Lesion delivery and scar formation in catheter ablation for atrial fibrillation: The DECAAF II trial

BackgroundThe Efficacy of Delayed Enhancement MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation of Atrial Fibrillation randomized trial showed no difference in atrial fibrillation (AF) recurrence with additional delayed enhancement magnetic resonance imaging (DE-MRI) fibrosis-targeted ablation to pulmonary vein isolation (PVI) in persistent AF. ObjectiveWe evaluated the effect of lesion delivery on ablation-induced scarring and AF recurrence. MethodsLesions delivered, targeting fibrotic and nonfibrotic areas identified from preablation DE-MRI, were studied in relation to ablation-induced scarring on 3-month DE-MRI, including their association with arrhythmia recurrence. ResultsA total of 593 patients treated with radiofrequency were analyzed: 293 (49.4%) underwent PVI and 300 (50.6%) underwent additional fibrosis-guided ablation. Lesion analysis showed that 80.9% in the MRI fibrosis-guided group vs 16.5% in the PVI group (P < .001) had ≥40% of baseline fibrosis targeted. MRI assessment of ablation-induced scar showed that 44.8% of fibrosis-guided ablation and 15.5% of PVI had ≥40% of their fibrosis covered by scar (P < .001), demonstrating significant attenuation from lesions delivered to scar formed. In the overall population, fibrosis coverage with scar was not associated with recurrence (hazard ratio [HR] 0.90; 95% confidence interval [CI] 0.80–1.01; P = .08 per 20% increase). In patients with baseline fibrosis < 20%, fibrosis coverage with scar was associated with lower recurrence than PVI (HR 0.85; 95% CI 0.73–0.97; P = .03), whereas the association was not significant when baseline fibrosis ≥ 20% (HR 0.97; 95% CI 0.80–1.17; P = .77). Significant center variation was observed in fibrosis targeting and coverage with scarring. ConclusionRadiofrequency ablation lesions do not uniformly result in scar formation. A post hoc analysis suggests reduced arrhythmia recurrence when ablation-induced scarring covers fibrotic regions in patients with low baseline fibrosis.

Mucus Mimic Hydrogel Coating for Lubricous, Antibiofouling, and Anti-Inflammatory Urinary Catheters.

Silicone is a common elastomer used in indwelling urinary catheters, and catheters are widely used in various medical applications due to their exceptional biocompatibility, hypoallergenic properties, and flexibility. However, silicones exhibit hydrophobic characteristics, lack inherent biolubrication, and are susceptible to nonspecific biosubstance adsorption, resulting in complications including but not limited to tissue trauma, postoperative pain, and urinary tract infections (UTIs). The development of effective surface designs for biomedical catheters to mitigate invasive damage and UITs has been a longstanding challenge. Herein, we present a novel approach to prepare a mucus mimic hydrogel coating. A thin layer of hydrogel containing xylitol is fabricated via photopolymerization. The surface modification technique and the interface-initiated hydrogel polymerization method ensure robust interfacial coherence. The resultant coating exhibits a low friction coefficient (CoF ≈ 0.1) for urinary catheter applications. Benefiting from the hydration layer and the antifouling of the xylitol unit, the xylitol hydrogel-coated surfaces (pAAAMXA) demonstrate outstanding antibiofouling properties against proteins (98.9% reduction relative to pristine polydimethylsiloxane (PDMS)). Furthermore, the pAAAMXA shows general adhesion resistance against bacteria primarily responsible for UITs (Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Methicillin-resistant strains of Staphylococcus aureus (MRSA), and Staphylococcus epidermidis (S. epidermidis)) without compromising biotoxicity (cell viability 98%). In vivo, catheters coated with the mucus mimic hydrogel displayed excellent biocompatibility, resistance to adhesion of bio substance, and anti-inflammatory characteristics. This work describes a promising alternative to conventional silicone catheters, offering potential for clinical interventional procedures with minimized complications.

Convergent ablation for persistent atrial fibrillation: A UK multicentre perspective.

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and remains a major cause of morbidity and mortality. Unfortunately, a significant proportion of patients have persistent AF, for which conventional catheter ablation is less effective. However, convergent ablation has emerged in recent years as a hybrid treatment targeting both the epicardium and endocardium in a multidisciplinary joint cardiothoracic and electrophysiology procedure, with promising efficacy outcomes in recent studies. This treatment is increasingly being performed in the United Kingdom. This review article discusses the rationale and evidence behind convergent ablation, along with factors that need to be considered when setting up a successful ablation service.

Novel ultralow positioning of the umbilical artery catheter: A prospective pilot study.

Thrombosis is a common complication of umbilical artery catheterization. The purpose of this study was to compare the novel ultralow umbilical artery catheter position (catheter tip at the junction of the umbilical and internal iliac arteries) versus the conventional high umbilical artery catheter position (tip in the aorta, above the diaphragm) for the incidence of thrombosis. This study was conducted in a nonacademic, tertiary-referral neonatal center. The insertion and placement of the umbilical artery catheter was performed under continuous ultrasound guidance. Serial ultrasound examinations were performed to identify thrombosis in 38 consecutive newborns with an umbilical artery catheter placed in the novel ultralow position. The control group consisted of 50 infants with an umbilical artery catheter placed in the standard position. The incidence of thrombosis requiring anticoagulant treatment was 22% in neonates with an umbilical artery catheter in the standard position. No thrombosis was detected in those with an umbilical artery catheter placed in the ultralow position. The study and control groups had similar catheter indwelling times (mean, 8.2 ± 4.1 vs. 8.5 ± 4.0 days, p = 0.687). This is the first report to present a novel position for the placement of umbilical artery catheters. The preliminary findings for the novel ultralow umbilical artery catheter position indicate that it may provide a safety benefit over the conventional umbilical artery catheter position.

History of stroke as a predictor of high left atrial fibrosis in patients with persistent atrial fibrillation-insight from the DECAAF II randomized trial.

There is a strong relationship between left atrial (LA) remodeling and ischemic stroke (IS) risk in atrial fibrillation (AF) patients. The Efficacy of Delayed Enhancement MRI-Guided Ablation vs. Conventional Catheter Ablation of Atrial Fibrillation (DECAAF-II) is the biggest MRI-based, randomized, multicenter clinical trial performed on persistent AF patients. The aim of this study is to evaluate the relationship between history of stroke and atrial fibrosis in the DECAAF II population. Persistent AF patients who underwent Late Gadolinium Enhancement Magnetic Resonance Imaging (LGE-MRI) were included in the study and divided into two different groups: those with a history of stroke and those without. Propensity score matching was performed to adjust for covariates. Atrial fibrosis was compared in both groups. Then, patients were divided into different fibrosis groups, using three different cut-offs of baseline atrial fibrosis: ≥ 15%, ≥ 20%, and ≥ 25%. Univariate logistic regression and adjusted multivariate analysis were performed to assess the effect of clinical characteristics and risk factors on baseline fibrosis. Eight-hundred forty-three patients were recruited in DECAAF II, of whom 70 (8.3%) had a history of stroke. Patients with history of stroke had a higher prevalence of hypertension (p = 0.043), diabetes (p = 0.014), and hyperlipidemia (p = 0.001). Seventy patients with no history of strokes were matched with patients with history of stroke to adjust for covariates using propensity score analysis. Patients in the stroke group had a significantly higher level of fibrosis than those without (20.2% vs. 8.1%, p = 0.017). Increased age was a significant predictor of all three baseline fibrosis classes (≥ 15%, ≥ 20%, and ≥ 25%). Additionally, history of stroke was found to be a predictor of baseline fibrosis ≥ 25% even after adjusting for other clinical characteristics and risk factors (OR = 1.98 [1.14-3.43], p = 0.01). Left atrial fibrosis level greater than 25% correlates with the history of previous stroke episodes in patients with persistent atrial fibrillation.

Advances in Multifunctional Electronic Catheters for Precise and Intelligent Diagnosis and Therapy in Minimally Invasive Surgery.

The advent of catheter-based minimally invasive surgical instruments has provided an effective means of diagnosing and treating human disease. However, conventional medical catheter devices are limited in functionalities, hindering their ability to gather tissue information or perform precise treatment during surgery. Recently, electronic catheters have integrated various sensing and therapeutic technologies through micro/nanoelectronics, expanding their capabilities. As micro/nanoelectronic devices become more miniaturized, flexible, and stable, electronic surgical catheters are evolving from simple tools to multiplexed sensing and theranostics for surgical applications. The review on multifunctional electronic surgical catheters is lacking and thus is not conducive to the reader's comprehensive understanding of the development trend in this field. This review covers the advances in multifunctional electronic catheters for precise and intelligent diagnosis and therapy in minimally invasive surgery. It starts with the summary of clinical minimally invasive surgical instruments, followed by the background of current clinical catheter devices for sensing and therapeutic applications. Next, intelligent electronic catheters with integrated electronic components are reviewed in terms of electronic catheters for diagnosis, therapy, and multifunctional applications. It highlights the present status and development potential of catheter-based minimally invasive surgical devices, while also illustrating several significant challenges that remain to be overcome.

Reduction in lower urinary tract mucosal microtrauma as an effect of reducing eyelet sizes of intermittent urinary catheters

Intermittent catheterization (IC) utilizing conventional eyelets catheters (CECs) for bladder drainage has long been the standard of care. However, when the tissue of the lower urinary tract comes in close proximity to the eyelets, mucosal suction often occurs, resulting in microtrauma. This study investigates the impact of replacing conventional eyelets with a drainage zone featuring multiple micro-holes, distributing pressure over a larger area. Lower pressures limit the suction of surrounding tissue into these micro-holes, significantly reducing tissue microtrauma. Using an ex vivo model replicating the intra-abdominal pressure conditions of the bladder, the intra-catheter pressure was measured during drainage. When mucosal suction occurred, intra-catheter images were recorded. Subsequently affected tissue samples were investigated histologically. The negative pressure peaks caused by mucosal suction were found to be very high for the CECs, leading to exfoliation of the bladder urothelium and breakage of the urothelial barrier. However, a micro-hole zone catheter (MHZC) with a multi-eyelet drainage zone showed significantly lower pressure peaks, with over 4 times lower peak intensity, thus inducing far less extensive microtraumas. Limiting or even eliminating mucosal suction and resulting tissue microtrauma may contribute to safer catheterizations in vivo and increased patient comfort and compliance.

Mussel-Inspired Sonochemical Nanocomposite Coating on Catheters for Prevention of Urinary Infections.

Catheter-associated urinary tract infections are the most common hospital-acquired infections and cause patient discomfort, increased morbidity, and prolonged stays, altogether posing a huge burden on healthcare services. Colonization occurs upon insertion, or later by ascending microbes from the rich periurethral flora, and is therefore virtually unavoidable by medical procedures. Importantly, the dwell time is a significant risk factor for bacteriuria because it gives biofilms time to develop and mature. This is why we engineer antibacterial and antibiofilm coating through ultrasound- and nanoparticle-assisted self-assembly on silicone surfaces and validate it thoroughly in vitro and in vivo. To this end, we combine bimetallic silver/gold nanoparticles, which exercise both biocidal and structural roles, with dopamine-modified gelatin in a facile and substrate-independent sonochemical coating process. The latter mussel-inspired bioadhesive potentiates the activity and durability of the coating while attenuating the intrinsic toxicity of silver. As a result, our approach effectively reduces biofilm formation in a hydrodynamic model of the human bladder and prevents bacteriuria in catheterized rabbits during a week of placement, outperforming conventional silicone catheters. These results substantiate the practical use of nanoparticle-biopolymer composites in combination with ultrasound for the antimicrobial functionalization of indwelling medical devices.

Comparing an Integrated Amphiphilic Surfactant to Traditional Hydrophilic Coatings for the Reduction of Catheter-Associated Urethral Microtrauma.

Hydrophilic-coated intermittent catheters have improved the experience of intermittent urinary catheterization for patients compared to conventional gel-lubricated uncoated catheters. However, the incorporation of polyvinylpyrrolidone (PVP) within hydrophilic coatings can lead to significant issues with coating dry-out. Consequently, increased force on catheter withdrawal may cause complications, including urethral microtrauma and pain. Standard methods of evaluating catheter lubricity lack physiological relevance and an understanding of the surface interaction with the urethra. The tribological performance and urethral interaction of commercially available hydrophilic PVP-coated catheters and a coating-free integrated amphiphilic surfactant (IAS) catheter were evaluated by using a biomimetic urethral model designed from a modified coefficient of friction (CoF) assay. T24 human urothelial cells were cultured on customized silicone sheets as an alternate countersurface for CoF testing. Hydrophilic PVP-coated and coating-free IAS catheters were hydrated and the CoF obtained immediately following hydration, or after 2 min, mimicking in vivo indwell time for urine drainage. The model was observed for urethral epithelial cell damage postcatheterization. The majority of hydrophilic PVP-coated catheters caused significantly greater removal of cells from the monolayer after 2 min indwell time, compared to the IAS catheter. Hydrophilic PVP-coated catheters were shown to cause more cell damage than the coating-free IAS catheter. A biomimetic urethral model provides a more physiologically relevant model for understanding the factors that govern the frictional interface between a catheter surface and urethral tissue. From these findings, the use of coating-free IAS catheters instead of hydrophilic PVP-coated catheters may help reduce urethral microtrauma experienced during catheter withdrawal from the bladder, which may lead to a lower risk of infection.

Impact of Contact Force on Pulsed Field Ablation Outcomes Using Focal Point Catheter.

Conventional focal radiofrequency catheters may be modified to enable multiple energy modalities (radiofrequency or pulsed field [PF]) with the benefit of contact force (CF) feedback, providing greater flexibility in the treatment of arrhythmias. Information on the impact of CF on lesion formation in PF ablations remains limited. An in vivo study was performed with 8 swine using an investigational dual-energy CF focal catheter with local impedance. Experiment I: To evaluate atrial lesion formation, contiguity, and width, a point-by-point approach was used to create an intercaval line. The distance between the points was prespecified at 4±1 mm. Half of the line was created with radiofrequency energy, whereas the other half utilized PF (single 2.0 kV application with a proprietary waveform). Experiment II: To evaluate single application lesion dimensions with a proprietary waveform, discrete ventricular lesions were performed with PFA (single 2.0 kV application) with targeted levels of CF: low, 5 to 15 g; medium, 20 to 30 g; and high, 35 to 45 g. Following 1 week of survival, animals underwent endocardial/epicardial remapping, and euthanasia to enable histopathologic examination. Experiment I: Both energy modalities resulted in a complete intercaval line of transmural ablation. PF resulted in significantly wider lines than radiofrequency: minimum width, 14.9±2.3 versus 5.0±1.6 mm; maximum width, 21.8±3.4 versus 7.3±2.1 mm, respectively; P<0.01 for each. Histology confirmed transmural lesions with both modalities. Experiment II: With PF, lesion depth, width, and volume were larger with higher degrees of CF (depth: r=0.82, P<0.001; width: r=0.26, P=0.052; and volume: r=0.55, P<0.001), with depth increasing at a faster rate than width. The mean depths were as follows: low (n=17), 4.3±1.0 mm; medium (n=26), 6.4±1.2 mm; and high (n=14), 9.1±1.4 mm. Using the same focal point CF-sensing catheter, a novel PF ablation waveform with a single application resulted in transmural atrial lesions that were significantly wider than radiofrequency. Lesion depth showed a significant positive correlation with CF with depths of 6.4 mm at moderate CF.

La identificación subjetiva y ablación de impulsores auriculares mejora el control del ritmo en la fibrilación auricular persistente. Estudio CHAOS-AF

Introduction and objectivesThe optimal approach for persistent atrial fibrillation (AF) ablation remains unknown. In patients with persistent AF, we compared an ablation strategy based on pulmonary vein isolation (PVI) plus ablation of drivers (PVI+D), with a conventional PVI-only approach performed in a 1:1 propensity score-matched cohort. MethodsDrivers were subjectively identified using conventional high-density mapping catheters (IntellaMap ORION, PentaRay NAV or Advisor HD Grid), without dedicated software, as fractionated continuous or quasicontinuous electrograms on 1 to 2 adjacent bipoles, which were ablated first; and as sites with spatiotemporal dispersion (the entire cycle length comprised within the mapping catheter) plus noncontinuous fractionation, which were only targeted in patients without fractionated continuous electrograms, or without AF conversion after ablation of fractionated continuous electrograms. Ablation included PVI plus focal or linear ablation targeting drivers. ResultsA total of 50 patients were included in each group (61±10 years, 25% women). Fractionated continuous electrograms were found and ablated in 21 patients from the PVI+D group (42%), leading to AF conversion in 7 patients. In the remaining 43 patients, 143 sites with spatiotemporal dispersion plus noncontinuous fractionation were targeted. Globally, AF conversion was achieved in 21 patients (42%). The PVI+D group showed lower atrial arrhythmia recurrences at 1 year of follow-up (30.6% vs 48%; P=.048) and at the last follow-up (46% vs 72%; P=.013), and less progression to permanent AF (10% vs 40%; P=.001). ConclusionsSubjective identification and ablation of drivers, added to PVI, increased 1-year freedom from atrial arrhythmia and decreased long-term recurrences and progression to permanent AF.

Efficacy of a Novel Tapered Contrast Catheter for Endoscopic Ultrasound-Guided Hepaticogastrostomy: A Multicenter Study.

Background: Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is an alternative for failed endoscopic retrograde cholangiopancreatography (ERCP), with current success rates of 65-84% considered suboptimal. A novel ERCP catheter (SHOREN, Kaneka Corporation, Osaka, Japan) with a tapered 3.3-French tip may facilitate smoother insertion, potentially improving outcomes. Methods: This retrospective analysis encompassed EUS-HGS procedures conducted from January 2021 to August 2023 at four institutions. The aim of this study was to compare the performance of conventional and novel ERCP contrast catheters regarding the success rate of single-attempt catheter insertion, failure rates, technical success rates, and incidence of adverse events. Results: The study included 48 patients; 26 underwent EUS-HGS using conventional catheters and 22 with the novel catheter. The novel catheter achieved higher success rates in single-attempt insertions (96.5% vs. 80.8%) and lower failure rates (4.6% vs. 7.7%). The occurrence of bile peritonitis was comparable between the two groups. Conclusions: The novel ERCP contrast catheter with a tapered tip appears to contribute to successful catheter insertion and is useful for EUS-HGS.

Balloon dacryoplasty: A boon for dacryologists in managing persistent congenital nasolacrimal duct obstructions.

To study the outcomes of balloon dacryoplasty (BD) or (BDCP) in children with persistent congenital nasolacrimal duct obstruction (pCNLDO) by using new and reused balloon catheters. Our retrospective analysis focused on managing pCNLDO by using the BD or BDCP technique. The study included children aged >1 year to <12 years who underwent single or multiple probings before. Our specific lacrimal workup included a detailed history and examination, as published earlier. We used conventional, straight, 2 mm × 13 mm/3 mm × 15 mm lacrimal balloons (FCI, Ophthacath). We have described a technique to use the same catheter for three BD procedures (1 new + 2 reuse). The outcomes were categorized as complete success, partial success, and failure. The minimum follow-up of each child was 6 months. We analyzed 64 children (89 eyes) with a mean age of 58 months (15-132 months). All children (100%) had epiphora with discharge and positive FDDT. All children underwent BD under general anesthesia - new balloons in 59 eyes and reused balloons in 30 eyes. The balloons were plasma sterilized akin to vitrectomy cutters and tubings of phaco machines. We noted three leaks from reused balloons (2 from the balloon tip and 1 from the plastic hub). At a mean follow-up of 14.5 months, complete success was noted in 77 eyes (86.5%) (52 new and 25 reuse), while 8 eyes had partial success (8.9%) (4 new and 4 reuse). Failure of BD was noted in four eyes (4.5%) (3 new and 1 reuse). None had significant complications with new or reused balloons. BD or BDCP is a quick, safe, easy, and effective procedure that resolves pCNLDO symptoms satisfactorily. Carefully reusing a conventional balloon catheter is possible with comparable efficacy and no additional complications in pCNLDO.

29. SOFT ROBOTICS APPLIED TO MEDICINE: STEERABLE TIP CATHETER GUIDED BY COMPUTER VISION

Abstract Introduction A soft, biocompatible, and deformation-controlled robotic catheter, guided by computer vision and propelled by the pressurized injection of a saline solution, has been developed. The catheter incorporates a camera at its end to navigate through the human circulatory system to the point where the problem is located and it can release the appropriate surgical instruments for the situation, for example, microscalpel, laser or even a microrobot. This work contributes to the reduction of the risks associated with conventional catheterization, such as unwanted punctures, and eliminates the need to use radiation on the patient for guidance. Methods Finite element simulation models are created in COMSOL to evaluate the performance of hydraulically actuated deformable catheter designs. The catheter is manufactured using flexible materials through additive manufacturing and curing of a biocompatible silicone, PDMS, on molds. Experimental measurements include the pressure reached by the saline solution, the curvature achieved by the catheter, the distance traveled within the conduit system, and the acquisition and processing of images of the traversed conduits. Results Simulation results identify the optimal design among the considered alternatives. A prototype of the catheter is fabricated, and its movement is precisely controlled to navigate safely within a conduit. Conclusion The feasibility of a soft and autonomous catheter with the desired characteristics and behavior to contribute to the reduction of risks associated with catheterization practices is demonstrated.