Distal Tip Research Articles

DISTAL CEMENT MANTLE THICKNESS AND POSITION OF STEM TIP ARE PREDICTORS OF PERIPROSTHETIC FRACTURES IN CEMENTED TAPERED FEMORAL STEMS

Periprosthetic femoral fractures are increasingly seen in recent years, adding considerable burden to the National Health Service. These require complex revision or fixation and prolonged post-operative care, with significant morbidity with associated costs. The purpose of this study was to assess whether the size of femoral cement mantle is associated with periprosthetic femoral fractures (PPF).This retrospective study was carried out on a cohort of 49 patients (Fracture Group - FG) who previously had a revision procedure following a proximal PPF between 2010 and 2021. Inclusion criteria – all primary cemented total hip replacements (THR). Exclusion criteria – complex primary THR, any implant malposition that required early revision surgery or any pre-fracture stem loosening. The antero-posterior (AP) radiographs from this cohort of patients were assessed and compared to an age, sex, time since THR-matched control group of 49 patients without PPF (Control Group - CG). Distal cement mantle area (DCMA) was calculated on an AP radiograph of hip; the position of the femoral stem tip prior to fracture was also recorded: valgus, varus or central. Limitations: AP radiographs only. Statistical analyses were performed using Microsoft® Excel.Chi-square test demonstrated statistically significant difference in DCMA between FG and CG. DCMA of 700 to 900 mm² appeared to be protective when compared to DCMA of 0 to 300 mm². Also, a valgus position observed in 23% in FG Vs 4 % in CG increased the risk, with a smaller area of DCMA.This study demonstrates and recommends that a size of 700 – 900 mm² of the DCMA is protective against periprosthetic fractures, which are further influenced by the positioning of the distal stem tip. This could be due to the gradual decrease in the stiffness gradient from proximal to distal around the stem tip than steep changes, thereby decreasing possibility of a stress riser just distal to the cement mantle or restrictor. Further biomechanical research specific to this finding may be helpful to validate the observation, progressing to suggest a safe standardised surgical technique.

Detecting lesion-specific ischemia in patients with coronary artery disease with computed tomography fractional flow reserve measured at different sites

ObjectivesWhether a stenosis can cause hemodynamic lesion-specific ischemia is critical for the treatment decision in patients with coronary artery disease (CAD). Based on coronary computed tomography angiography (CCTA), CT fractional flow reserve (FFRCT) can be used to assess lesion-specific ischemia. The selection of an appropriate site along the coronary artery tree is vital for measuring FFRCT. However the optimal site to measure FFRCT for a target stenosis remains to be adequately determined. The purpose of this study was to determine the optimal site to measure FFRCT for a target lesion in detecting lesion-specific ischemia in CAD patients by evaluating the performance of FFRCT measured at different sites distal to the target lesion in detecting lesion-specific ischemia with FFR measured with invasive coronary angiography (ICA) as reference standard.MethodsIn this single-center retrospective cohort study, a total of 401 patients suspected of having CAD underwent invasive ICA and FFR between March 2017 and December 2021 were identified. 52 patients having both CCTA and invasive FFR within 90 days were enrolled. Patients with vessels 30%-90% diameter stenosis as determined by ICA were referred to invasive FFR evaluation, which was performed 2–3 cm distal to the stenosis under the condition of hyperemia. For each vessel with 30%–90% diameter stenosis, if only one stenosis was present, this stenosis was selected as the target lesion; if serial stenoses were present, the stenosis most distal to the vessel end was chosen as the target lesion. FFRCT was measured at four sites: 1 cm, 2 cm, and 3 cm distal to the lower border of the target lesion (FFRCT-1 cm, FFRCT-2 cm, FFRCT-3 cm), and the lowest FFRCT at the distal vessel tip (FFRCT-lowest). The normality of quantitative data was assessed using the Shapiro–Wilk test. Pearson's correlation analysis and Bland–Altman plots were used for assessing the correlation and difference between invasive FFR and FFRCT. Correlation coefficients derived from Chi-suqare test were used to assess the correlation between invasive FFR and the cominbaiton of FFRCT measred at four sites. The performances of significant obstruction stenosis (diameter stenosis ≥ 50%) at CCTA and FFRCT measured at the four sites and their combinations in diagnosing lesion-specific ischemia were evaluated by receiver-operating characteristic (ROC) curves using invasive FFR as the reference standard. The areas under ROC curves (AUCs) of CCTA and FFRCT were compared by the DeLong test.ResultsA total of 72 coronary arteries in 52 patients were included for analysis. Twenty-five vessels (34.7%) had lesion-specific ischemia detected by invasive FFR and 47 vesseles (65.3%) had no lesion-spefifice ischemia. Good correlation was found between invasive FFR and FFRCT-2 cm and FFRCT-3 cm (r = 0.80, 95% CI, 0.70 to 0.87, p < 0.001; r = 0.82, 95% CI, 0.72 to 0.88, p < 0.001). Moderate correlation was found between invasive FFR and FFRCT-1 cm and FFRCT-lowest (r = 0.77, 95% CI, 0.65 to 0.85, p < 0.001; r = 0.78, 95% CI, 0.67 to 0.86, p < 0.001). FFRCT-1 cm + FFRCT-2 cm, FFRCT-2 cm + FFRCT-3 cm, FFRCT-3 cm + FFRCT-lowest, FFRCT-1 cm + FFRCT-2 cm + FFRCT-3 cm, and FFRCT-2 cm + FFRCT-3 cm + FFRCT-lowest were correatled with invasive FFR (r = 0.722; 0.722; 0.701; 0.722; and 0.722, respectively; p < 0.001 for all). Bland–Altman plots revealed a mild difference between invasive FFR and the four FFRCT (invasive FFR vs. FFRCT-1 cm, mean difference -0.0158, 95% limits of agreement: -0.1475 to 0.1159; invasive FFR vs. FFRCT-2 cm, mean difference 0.0001, 95% limits of agreement: -0.1222 to 0.1220; invasive FFR vs. FFRCT-3 cm, mean difference 0.0117, 95% limits of agreement: -0.1085 to 0.1318; and invasive FFR vs. FFRCT-lowest, mean difference 0.0343, 95% limits of agreement: -0.1033 to 0.1720). AUCs of CCTA, FFRCT-1 cm, FFRCT-2 cm, FFRCT-3 cm, and FFRCT-lowest in detecting lesion-specific ischemia were 0.578, 0.768, 0.857, 0.856 and 0.770, respectively. All FFRCT had a higher AUC than CCTA (all p < 0.05), FFRCT-2 cm achieved the highest AUC at 0.857. The AUCs of FFRCT-2 cm and FFRCT-3 cm were comparable (p > 0.05). The AUCs were similar between FFRCT-1 cm + FFRCT-2 cm, FFRCT-3 cm + FFRCT-lowest and FFRCT-2 cm alone (AUC = 0.857, 0.857, 0.857, respectively; p > 0.05 for all). The AUCs of FFRCT-2 cm + FFRCT-3 cm, FFRCT-1 cm + FFRCT-2 cm + FFRCT-3 cm, FFRCT-and 2 cm + FFRCT-3 cm + FFRCT-lowest (0.871, 0.871, 0.872, respectively) were slightly higher than that of FFRCT-2 cm alone (0.857), but without significnacne differences (p > 0.05 for all).ConclusionsFFRCT measured at 2 cm distal to the lower border of the target lesion is the optimal measurement site for identifying lesion-specific ischemia in patients with CAD.

Toeing the line between regeneration and fibrosis.

Understanding the remarkable capacity of vertebrates to naturally regenerate injured body parts has great importance for potential translation into human therapeutic applications. As compared to other vertebrates, mammals have low regenerative capacity for composite tissues like the limb. However, some primates and rodents can regenerate the distal tips of their digits following amputation, indicating that at least very distal mammalian limb tissues are competent for innate regeneration. It follows that successful digit tip regenerative outcome is highly dependent on the location of the amputation; those proximal to the position of the nail organ do not regenerate and result in fibrosis. This distal regeneration versus proximal fibrosis duality of the mouse digit tip serves as a powerful model to investigate the driving factors in determining each process. In this review, we present the current understanding of distal digit tip regeneration in the context of cellular heterogeneity and the potential for different cell types to function as progenitor cells, in pro-regenerative signaling, or in moderating fibrosis. We then go on to discuss these themes in the context of what is known about proximal digit fibrosis, towards generating hypotheses for these distinct healing processes in the distal and proximal mouse digit.

The Voltage-Gated Sodium Channel in Drosophila, Para, Localizes to Dendrites As Well As Axons in Mechanosensitive Chordotonal Neurons.

The fruit fly Drosophila melanogaster has provided important insights into how sensory information is transduced by transient receptor potential (TRP) channels in the peripheral nervous system (PNS). However, TRP channels alone have not been able to completely model mechanosensitive transduction in mechanoreceptive chordotonal neurons (CNs). Here, we show that, in addition to TRP channels, the sole voltage-gated sodium channel (NaV) in Drosophila, Para, is localized to the dendrites of CNs. Para is localized to the distal tip of the dendrites in all CNs, from embryos to adults, and is colocalized with the mechanosensitive TRP channels No mechanoreceptor potential C (NompC) and Inactive/Nanchung (Iav/Nan). Para localization also demarcates spike initiation zones (SIZs) in axons and the dendritic localization of Para is indicative of a likely dendritic SIZ in fly CNs. Para is not present in the dendrites of other peripheral sensory neurons. In both multipolar and bipolar neurons in the PNS, Para is present in a proximal region of the axon, comparable to the axonal initial segment (AIS) in vertebrates, 40-60 μm from the soma in multipolar neurons and 20-40 μm in bipolar neurons. Whole-cell reduction of para expression using RNAi in CNs of the adult Johnston's organ (JO) severely affects sound-evoked potentials (SEPs). However, the duality of Para localization in the CN dendrites and axons identifies a need to develop resources to study compartment-specific roles of proteins that will enable us to better understand Para's role in mechanosensitive transduction.

Supraclavicular Artery Island Flap for Head and Neck Oncologic Reconstruction: 15-year Experience, Past, Present, Future

Background: Head and neck reconstruction poses unique challenges due to the complex structure of the region. Primary goals include soft-tissue coverage, adequate color and texture match, and minimal donor-site morbidity. Local and musculocutaneous regional flaps have largely been replaced with fasciocutaneous free flaps (FFF) over recent years. The supraclavicular artery island flap (SCAIF), a locoregional, fasciocutaneous, axially-based flap, has been shown to produce similar outcomes to FFF. We present our 15-year experience using the SCAIF for head and neck reconstruction, discuss its evolution, and provide case examples for its range of indications. Methods: Retrospective chart review identified 128 patients who underwent reconstruction of the head and neck with the SCAIF between the years 2006-2021 at Tulane University Medical Center. Patient demographics, lengths of stay, operative times, surgical indications, and complications were recorded. Results: The cohort mean age was 66.9 years. Mean lengths of stay and follow-up times were 6.9 days and 9.1 months, respectively. The most common indications for SCAIF reconstruction were recurrent radiated neck disease (n=27, 21.1%), pharyngeal wall defects (n=23, 18.0%), and parotidectomy defects (n=21, 16.4%). Overall complication rate was 17.2%. Partial thickness flap loss (5.5%), contained pharyngeal leak (3.2%), and distal tip necrosis (2.4%) were the most common complications. No functional donor site morbidity was encountered. Conclusions: The SCAIF is a versatile, fasciocutaneous, axially-based flap able to produce similar outcomes to FFF in the reconstruction of the head and neck region while reducing costs, lengths of stay, operative times, and donor site morbidity.

The reverse LICAP flap: A laterally based submammary perforator flap for breast reconstruction

The traditional donor sites for autologous breast reconstruction include the abdomen, thigh, buttock, and posterior thorax. Herein, we describe the use of the reverse lateral intercostal perforator (LICAP) flap originating from the submammary region as an option for breast reconstruction. Fifteen patients (30 breasts) were included in this retrospective review. The procedure was performed for immediate reconstruction following a nipple sparing mastectomy utilizing an inframammary incision or an inverted T pattern with preservation of the fifth anterior intercostal perforator (n=8), volume replacement after implant explantation (n=5), and partial lower pole resurfacing with exteriorization of a portion of the LICAP skin paddle (n=2). Flap survival was achieved in all patients. Three flaps (10%) had 1-2cm of intraoperative distal tip ischemia, which was managed by excision prior to inset and closure. At the 12-month postoperative follow-up, stable results with good nipple position, breast shape, and projection were achieved in all patients. The reverse LICAP flap is a safe, effective, and reliable option for breast reconstruction following mastectomy.

(516) Maximizing Penile Prosthesis Length: Our Technique and Outcomes

Abstract Introduction The most common cause of patient regret after penile prosthesis surgery is penile shortening, which has been reported in up to 70% of patients postoperatively. Objective We sought to query a national database on average prosthesis length and describe our techniques to maximize cylinder sizes. Methods We performed a retrospective review of the Coloplast database of 3-piece penile prosthesis cases performed over the span of 1 year nationally and by a single high volume surgeon and compared average cylinder lengths. Results Between July 1, 2021 and June 27, 2022, 145 three piece penile prosthesis surgeries were performed at our institution. All were performed via a scrotal incision. Nationally, 32.8% were performed infrapubic while 58.1% were performed scrotal. The most prevalent cylinder length in our series was 22cm, compared to the most prevalent nationally of 20cm. (Table 1). Our technique to maximize cylinder length involves circumferential mobilization of the corporal bodies and corporal tissue sparing. After initial scrotal incision and dissection to the level of the penile compartment, circumferential mobilization of the corporal bodies is carried out. In addition, the ventral corporal dartos layer is meticulously peeled away. Corporal tissue sparing is carried out by employing 9” Metzenbaum scissors rather than sequential dilators for corporal tunneling. (Image 1). The benefit of this approach is the ability to create a dorsal compartment to the level of the triangular ligament of the glans, thereby extending the space to the level of the midglans. This maneuver minimizes placement of the prosthesis anteriorly at the level of the fossa navicularis and prevents floppy glans that would otherwise compromise maximum cylinder length. Conclusions Three piece penile prosthesis cylinder size can be maximized by circumferential mobilization of the corporal bodies, corporal sparing maneuvers, and the utilization of long Metzenbaum scissors for precise corporal tunneling, ensuring the distal cylinder tips are seated within the tip of the glans rather than at the coronal sulcus. This can help mitigate patient regret after prosthesis surgery. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast

P190 TWIDDLER’S SYNDROME IN A 96–YEAR–OLD PATIENT TREATED BY REPOSITIONING THE VENTRICULAR LEAD

Abstract A 96–years–old woman was admitted to our cardiological intensive care unit in December 2022 with atrioventricular dissociation, with a junctional ventricular escape rhythm at a rate of 38 beats per minute, and an atrial rhythm dissociated from the ventricular rhythm, at a rate of 80 beats per minute (Figure 1). The patient had a history of third–degree atrioventricular block, effectively treated with single–chamber pacemaker implantation (Assurity MRI SR, Abbott), operation performed approximately 10 months before access, in February 2022. The patient underwent a chest X–ray, which showed "coiling" of the ventricular catheter in the pacemaker pocket area (left subclavicular), with macroscopic dislocation of the ventricular electrode, which had its distal tip in the right atrium (Figure 2). Therefore, the clinical case was typical of Twiddler‘s syndrome. The patient would therefore have undergone revision surgery. An attempt was made to reposition the original lead, with passive fixation (Isoflex 1948/58, Abbott), by inserting a "straight" stylet, a procedure which was done effectively. The ventricular lead was repositioned in the right ventricular apex. The detected parameters were optimal (sensing 7 mV, ventricular barrier threshold 0.5 mV/0.4 ms, impedance 797 Ohm). The result was considered acceptable. The remainder of the hospital stay was without complications. The patient was discharged on the fifth day in good general condition. Twiddler syndrome is defined as a dislocation of one or more catheters, resulting in the catheters "coiling" in the pocket of the device. It is usually related to the manipulation of the generator by the patient itself. It usually occurs within a year of implantation and is usually more common in females, the elderly, the obese, pediatric patients, or patients with psychiatric disorders. The identification of patients at risk for this pathology, the adequate education of the patient and family regarding the management of the device, the use of catheters with active fixation, as well as the fixation of the generator device to the pectoral muscle, through non–absorbable sutures. In the case described, the patient denied manipulation of the device, which however could not be excluded, given the age of the patient.

Accuracy of radiographic techniques in detection of the calcaneofibular ligament calcaneal insertion for lateral ankle ligament complex surgery.

Grade III ankle sprains that fail conservative treatment can require surgical management. Anatomic procedures have been shown to properly restore joint mechanics, and precise localization of insertion sites of the lateral ankle complex ligaments can be determined through radiographic techniques. Ideally, radiographic techniques that are easily reproducible intraoperatively will lead to a consistently well-placed CFL reconstruction in lateral ankle ligament surgery. To determine the most accurate method to locate the calcaneofibular ligament (CFL) insertion radiographically. MRIs of 25 ankles were utilized to identify the "true" insertion of the CFL. Distances between the true insertion and three bony landmarks were measured. Three proposed methods (Best, Lopes, and Taser) for determining the CFL insertion were applied to lateral ankle radiographs. X and Y coordinate distances were measured from the insertion found on each proposed method to the three bony landmarks: the most superior point of the postero-superior surface of the calcaneus, the posterior most aspect of the sinus tarsi, and the distal tip of the fibula. X and Y distances were compared to the true insertion found on MRI. All measurements were made using a picture archiving and communication system. The average, standard deviation, minimum, and maximum were obtained. Statistical analysis was performed using repeated measures ANOVA, and a post hoc analysis was performed with the Bonferroni test. The Best and Taser techniques were found to be closest to the true CFL insertion when combining X and Y distances. For distance in the X direction, there was no significant difference between techniques (P = 0.264). For distance in the Y direction, there was a significant difference between techniques (P = 0.015). For distance in the combined XY direction, there was a significant difference between techniques (P = 0.001). The CFL insertion as determined by the Best method was significantly closer to the true insertion compared to the Lopes method in the Y (P = 0.042) and XY (P = 0.004) directions. The CFL insertion as determined by the Taser method was significantly closer to the true insertion compared to the Lopes method in the XY direction (P = 0.017). There was no significant difference between the Best and Taser methods. If the Best and Taser techniques can be readily used in the operating room, they would likely prove the most reliable for finding the true CFL insertion.

Aristaless1 has a dual role in appendage formation and wing color specification during butterfly development

BackgroundHighly diverse butterfly wing patterns have emerged as a powerful system for understanding the genetic basis of phenotypic variation. While the genetic basis of this pattern variation is being clarified, the precise developmental pathways linking genotype to phenotype are not well understood. The gene aristaless, which plays a role in appendage patterning and extension, has been duplicated in Lepidoptera. One copy, aristaless1, has been shown to control a white/yellow color switch in the butterfly Heliconius cydno, suggesting a novel function associated with color patterning and pigmentation. Here we investigate the developmental basis of al1 in embryos, larvae, and pupae using new antibodies, CRISPR/Cas9, RNAi, qPCR assays of downstream targets, and pharmacological manipulation of an upstream activator.ResultsWe find that Al1 is expressed at the distal tips of developing embryonic appendages consistent with its ancestral role. In developing wings, we observe Al1 accumulation within developing scale cells of white H. cydno during early pupation while yellow scale cells exhibit little Al1 at this time point. Reduced Al1 expression is also associated with yellow scale development in al1 knockouts and knockdowns. We propose that Al1 expression in future white scales might be related to an observed downregulation of the enzyme Cinnabar and other genes that synthesize and transport the yellow pigment, 3–hydroxykynurenine (3-OHK). Finally, we provide evidence that Al1 activation is under the control of Wnt signaling.ConclusionsWe propose a model in which high levels of Al1 during early pupation, which are mediated by Wnt, are important for melanic pigmentation and specifying white portions of the wing while reduced levels of Al1 during early pupation promote upregulation of proteins needed to move and synthesize 3-OHK, promoting yellow pigmentation. In addition, we discuss how the ancestral role of aristaless in appendage extension may be relevant in understanding the cellular mechanism behind color patterning in the context of the heterochrony hypothesis.

Separable Tendon-Driven Robotic Manipulator with a Long, Flexible, Passive Proximal Section.

This work tackles practical issues which arise when using a tendon-driven robotic manipulator (TDRM) with a long, flexible, passive proximal section in medical applications. Tendon-driven devices are preferred in medicine for their improved outcomes via minimally invasive procedures, but TDRMs come with unique challenges such as sterilization and reuse, simultaneous control of tendons, hysteresis in the tendon-sheath mechanism, and unmodeled effects of the proximal section shape. A separable TDRM which overcomes difficulties in actuation and sterilization is introduced, in which the body containing the electronics is reusable and the remainder is disposable. An open-loop redundant controller which resolves the redundancy in the kinematics is developed. Simple linear hysteresis compensation and re-tension compensation based on the physical properties of the device are proposed. The controller and compensation methods are evaluated on a testbed for a straight proximal section, a curved proximal section at various static angles, and a proximal section which dynamically changes angles; and overall, distal tip error was reduced.

ALS Causative Mutations in KIF5A Disrupt Autoinhibition Leading to Toxic Gain of Function (P8-8.002)

<h3>Objective:</h3> The objective of this study was to elucidate the pathogenic mechanisms of ALS causative mutations in motor protein KIF5A. <h3>Background:</h3> KIF5A is a neuronal specific subunit of Kinesin-1, which is a microtubule motor protein that plays roles in axonal transport and cytoskeletal regulation. Mutations in distinct regions of Kinesin-1 lead to a broad range of neurologic diseases. KIF5A enables Kinesin-1 to walk along microtubules and transport various cargos such as mitochondria and RNA granules into the distal axon. ALS-causative mutations in KIF5A affect the structure of the domain of the protein that functions in cargo binding and autoregulation. However, the consequences of ALS-causative mutations on disease pathogenesis are not fully understood. Our central hypothesis was that KIF5A ALS mutations disrupt cargo binding and/or autoregulation leading to neurodegeneration. <h3>Design/Methods:</h3> We generated <i>in vitro</i> models of KIF5A ALS using transient transfection of disease causative variants into neuroblastoma cell lines. We performed immunofluorescence staining and confocal imaging to visualize the distribution of motor proteins KIF5A, KIF5B, and Dynein. We utilized Drosophila S2 cell lines to study mitochondrial motility using live-imaging. <h3>Results:</h3> Whereas wild type (WT) KIF5A displayed relatively homogeneous distribution, ALS mutant KIF5A developed dramatic accumulation within distal neurites. Co-expression of the ALS mutant protein with the WT caused it to accumulate as well. Mitochondria displayed similar mislocalization to distal neurites. No change was seen in the distribution of KIF5B or Dynein. <h3>Conclusions:</h3> We found that ALS mutant KIF5A caused dramatic accumulation of mutant and WT protein as well as mitochondrial within distal neurite tips. These findings suggest that ALS mutation disrupts its autoinhibition causing mislocalization of its cargos through gain of function. These changes in distribution are specific to KIF5A containing motors. Our findings establish dysregulation of KIF5A activity as the underlying pathogenic mechanism for KIF5A ALS. <b>Disclosure:</b> Dr. Brent has received research support from The American Academy of Neurology. Mr. Sterling-Angus has nothing to disclose. Dr. Deng has nothing to disclose.

MP35-13 INITIAL EXPERIENCE AND CLINICAL ASSESSMENT OF A NOVEL SINGLE-USE FLEXIBLE URETEROSCOPE

You have accessJournal of UrologyCME1 Apr 2023MP35-13 INITIAL EXPERIENCE AND CLINICAL ASSESSMENT OF A NOVEL SINGLE-USE FLEXIBLE URETEROSCOPE Kevin Koo, Jamal Alamiri, Kevin Hanna, Lindsay White, Garrett Ungerer, Jayson Kemble, Carly Thompson, and Aaron Potretzke Kevin KooKevin Koo More articles by this author , Jamal AlamiriJamal Alamiri More articles by this author , Kevin HannaKevin Hanna More articles by this author , Lindsay WhiteLindsay White More articles by this author , Garrett UngererGarrett Ungerer More articles by this author , Jayson KembleJayson Kemble More articles by this author , Carly ThompsonCarly Thompson More articles by this author , and Aaron PotretzkeAaron Potretzke More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003269.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Single-use (SU) ureteroscopes offer cost-effective advantages over traditional reusable devices in clinical settings with increased risk of device damage. One technical drawback of SU scopes is decreased brightness and clarity of the visual field, which may impair case completion. The Karl Storz FLEX-XC1 is a novel single-use flexible ureteroscope that uses the same video graphics platform as its reusable digital counterpart. We aimed to evaluate the technical performance of the XC1 in initial clinical use. METHODS: We reviewed a series of consecutive ureteroscopy procedures performed by 2 endourologists. We used the XC1 for indications in which we typically use a single-use device: stone burden >15 mm overall or >10 mm in the lower pole; expected case duration >60 min; bilateral procedure; distorted anatomy. For each case, we assessed pre-case tip deflection, intraoperative mechanical failure, and clinical outcomes. Surgeons rated visual clarity, image quality, and mechanical handling on a 1 to 5 Likert scale. RESULTS: A total of 21 procedures were attempted using XC1, and 20 (95%) were completed successfully. Pre-case incomplete deflection was noted in 7 (33%) cases: pre-case upward deflection was <270° in 4 (19%) cases (range 200-250°), and downward deflection was <270° in 5 (24%) cases (range 180-250°). Pre-case incomplete deflection did not preclude completion of any case. Three intraoperative malfunctions occurred: rotational twisting of the deflectable distal tip (2 cases, 10%) and inability to pass a 365-micron laser fiber fully through the working channel (1 case, 5%), requiring conversion to another device. Visual clarity, image quality, and mechanical handling were rated as 4 (very good) or 5 (excellent) in 100%, 100%, and 76% of cases. Figure 1 shows representative image quality between the reusable digital Storz FLEX-XC, SU Storz FLEX-XC1, and SU Dornier AXIS. No device-specific or general 30-day complications were observed. CONCLUSIONS: In this pilot trial of the FLEX-XC1, visual clarity and image quality were subjectively similar to reusable digital devices and rated highly by operators. We observed incomplete deflection in 33% of cases and mechanical failure in 1 case. XC1 may be advantageous in prolonged cases where maintaining visual clarity is paramount. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e474 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kevin Koo More articles by this author Jamal Alamiri More articles by this author Kevin Hanna More articles by this author Lindsay White More articles by this author Garrett Ungerer More articles by this author Jayson Kemble More articles by this author Carly Thompson More articles by this author Aaron Potretzke More articles by this author Expand All Advertisement PDF downloadLoading ...

Investigation of the efficacy of an innovative endoscope drying and storage method in a simulated ERCP setting.

Background and study aims Drying after cleaning and disinfection is essential in the reprocessing of endoscopes since microorganisms can grow and form biofilms on wet surfaces. In this experimental non-clinical study, we investigated the efficacy of a novel, fast-drying method when reprocessing duodenoscopes. Methods During a series of 40 tests, three duodenoscopes were exposed to an artificial test soil containing supraphysiological loads of four types of gut microorganisms in a non-clinical ERCP simulation, followed by reprocessing and drying with the PlasmaTYPHOON. Cultures of the distal tip and working channel were acquired immediately after automated decontamination and after drying with the PlasmaTYPHOON. Cobalt chloride paper tests and borescope inspections were used to evaluate drying efficacy. Results Contamination of the working channels dropped from 86.4 % post-decontamination to 33.6 % post-drying, with 94 % of the positive post-drying samples belonging to one duodenoscope. This duodenoscope showed persistent contamination with P. aeruginosa in the working channel. The other two duodenoscopes only showed low levels of P. aeruginosa in post-decontamination channel samples, but not after drying. Cobalt chloride paper tests and borescope inspections revealed good drying efficacy. Conclusions Positive cultures for gut microorganisms were often found in wet endoscopes post-decontamination. The PlasmaTYPHOON is an effective fast-drying method capable of abolishing nearly all remaining microorganisms after decontamination provided no biofilm has developed, even when using a supraphysiological concentration of bacterial load. The clinical use of the PlasmaTYPHOON has the potential to reduce endoscope contamination, the use of wet contaminated endoscopes and therefore the risk of patient infection.

Senescence-induced alteration of circadian phagocytic activity of retinal pigment epithelium cell line ARPE-19

Renewal of retinal photoreceptor outer segments is conducted through daily shedding of distal photoreceptor outer segment tips and subsequent their phagocytosis by the adjacent retinal pigment epithelium (RPE) monolayer. Dysregulation of the diurnal clearance of photoreceptor outer segment tips has been implicated in age-related retinal degeneration, but it remains to be clarified how the circadian phagocytic activity of RPE cells is modulated by senescence. In this study, we used the human RPE cell line ARPE-19 to investigate whether hydrogen peroxide (H2O2)-induced senescence in ARPE-19 cells alters the circadian rhythm of their phagocytic activity. After synchronization of the cellular circadian clock by dexamethasone treatment, the phagocytic activity of normal ARPE-19 cells exhibited significant 24-h oscillation, but this oscillation was modulated by senescence. The phagocytic activity of senescent ARPE-19 cells increased constantly throughout the 24-h period, which still exhibited blunted circadian oscillation, accompanied by an alteration in the rhythmic expression of circadian clock genes and clock-controlled phagocytosis-related genes. The expression levels of REV-ERBα, a molecular component of the circadian clock, were constitutively increased in senescent ARPE-19 cells. Furthermore, pharmacological activation of REV-ERBα by its agonist SR9009 enhanced the phagocytic activity of normal ARPE-19 cells and increased the expression of clock-controlled phagocytosis-related genes. Our present findings extend to understand the role of circadian clock in the alteration of phagocytic activity in RPE during aging. Constitutive enhancement of phagocytic activity of senescent RPE may contribute to age-related retinal degeneration.

Utility of a multipurpose catheter for transvenous extraction of old broken leads: A novel technique for fragile leads

Transvenous lead extraction has been possible since the 1980s. However, complications during lead extraction, such as the distal end fragment of the lead remaining in the myocardium or venous system and injury to the veins or heart, have been reported. The purpose of this study was to examine our method for complete removal of a separated lead, as extraction of long-term implanted devices is difficult using standard methods and may require additional procedures. The removal of leads with inner conductor coil and lead tip separated from outer insulation, conductor coil, and proximal ring electrode using a multipurpose catheter is reported. In total, 345 consecutive patients who underwent transvenous lead extraction (TLE) from April 2014 to March 2021 were retrospectively analyzed. Lead characteristics, device type, and indications for extraction were further analyzed in 20 patients who developed separation of the proximal ring electrode and outer conductor coil from the inner conductor and distal tip at the time of extraction. Extractions were performed using an excimer laser sheath laser and a Byrd polypropylene telescoping sheath (n = 15); laser, Byrd polypropylene telescoping sheath, and Evolution RL (n = 2); laser and Evolution RL (n = 3); Byrd polypropylene telescoping sheath and Evolution RL (n = 1); Byrd polypropylene telescoping sheath only (n = 4); and Evolution RL only (n = 2). Twenty-seven leads implanted for more than 10 years had lead separation. A multipurpose catheter was used to protect the fragile leads from further damage. All leads were completely extracted. All distal tip-to-proximal ring electrode separated leads were successfully removed using laser and other sheaths with the assistance of a multipurpose catheter, without any part of the leads remaining in the heart.

Cardiovascular computed tomography in the evaluation of post-TAVI prosthesis dysfunction: the thin line between hypo attenuated leaflet thickening and clinical valve thrombosis.

It is accepted that hypo attenuated leaflet thickening (HALT) can be detected in 12% and 32% of transcatheter aortic valve implantation (TAVI) patients on oral anticoagulation or dual antiplatelet therapy at 3 months, respectively.1 Clinically relevant TAVI thrombosis is rare, with up to 1% incidence.2 We present the case of an 86-year-old male with a history of ischemic cardiomyopathy, atrial fibrillation (on apixaban 5 mg BID), and 4 months post-TAVI (Sapien 3–29 mm) who presented to the Emergency Department with worsening dyspnea and elevated cardiac biomarkers: HS-Tn (1689 ng/L) and NT-proBNP (>5000 pg/mL). Echocardiogram showed new severe systolic dysfunction (left ventricular EF = 30%) and elevated gradients (compared to the basal post-TAVI study) with limited visualization of the valve (central figure, Panels A and B). He underwent invasive coronary angiography, which showed no coronary artery disease progression as to explain the clinical changes. Given the rapidly worsening clinical status, a cardiovascular computed tomography (CCT) was ordered over transesophageal echocardiogram for better evaluation. The CCT was acquired using retrospective gating without ECG dose modulation (IQon, Philips) for high-quality full-cycle images (Panels C–F). There was severe symmetrical tri-leaflet thickening with sparing of the distal tips (meniscal shape), classically described in HALT.3 The Hounsfield units were more consistent with thrombus (<100 HU) (Panel C), and significantly reduced tri-leaflet motion was also noted on functional images (see Supplementary data online, Video S1). Despite being treated with i.v. heparin and guideline-directed medical therapy for HFrEF, the patient developed refractory cardiogenic shock and expired. The best antithrombotic regimen for patients undergoing TAVI remains controversial.4 Bioprosthetic valve thrombosis involves a spectrum with different grades of clinical manifestation. The CCT is paramount for establishing the etiology of the dysfunction and providing prognostic information for patient management.5

Pulsed thulium laser blood vessel haemostasis as an alternative to bipolar forceps during neurosurgical tumour resection

Due to wavelength-specific water absorption, infrared lasers like the thulium laser emitting at 1940 nm wavelength proved to be suitable for coagulation in neurosurgery. Commonly bipolar forceps used for intraoperative haemostasis can cause mechanical and thermal tissue damage, whilst thulium laser can provide a tissue-gentle haemostasis through non-contact coagulation. The aim of this work is a less-damaging blood vessel coagulation by pulsed thulium laser radiation in comparison to standard bipolar forceps haemostasis. Ex vivo porcine blood vessels in brain tissue (0.34 ± 0.20 mm diameter) were irradiated in non-contact with a thulium laser in pulsed mode (1940 nm wavelength, 15 W power, 100–500 ms pulse duration), with a CO2 gas flow provided simultaneously at the distal fibre tip (5 L/min). In comparison, a bipolar forceps was used at various power levels (20–60 W). Tissue coagulation and ablation were evaluated by white light images and vessel occlusion was visualised by optical coherence tomography (OCT) B-scans at a wavelength of 1060 nm. Coagulation efficiency was calculated by means of the quotient of the difference between the coagulation and ablation radius to the coagulation radius. Pulsed laser application achieved blood vessel occlusion rate of 92% at low pulse duration of 200 ms with no occurrence of ablation (coagulation efficiency 100%). Bipolar forceps showed an occlusion rate of 100%, however resulted in tissue ablation. Tissue ablation depth with laser application is limited to 40 μm and by a factor of 10 less traumatising than with bipolar forceps. Pulsed thulium laser radiation achieved blood vessel haemostasis up to 0.3 mm in diameter without tissue ablation and has proven to be a tissue-gentle method compared to bipolar forceps.

Reconstructing the dietary habits and trophic positions of the Longipterygidae (Aves: Enantiornithes) using neontological and comparative morphological methods.

The Longipterygidae are a unique clade among the enantiornithines in that they exhibit elongate rostra (≥60% total skull length) with dentition restricted to the distal tip of the rostrum, and pedal morphologies suited for an arboreal lifestyle (as in other enantiornithines). This suite of features has made interpretations of this group's diet and ecology difficult to determine due to the lack of analogous taxa that exhibit similar morphologies together. Many extant bird groups exhibit rostral elongation, which is associated with several disparate ecologies and diets (e.g., aerial insectivory, piscivory, terrestrial carnivory). Thus, the presence of rostral elongation in the Longipterygidae only somewhat refines trophic predictions of this clade. Anatomical morphologies do not function singularly but as part of a whole and thus, any dietary or ecological hypothesis regarding this clade must also consider other features such as their unique dentition. The only extant group of dentulous volant tetrapods are the chiropterans, in which tooth morphology and enamel thickness vary depending upon food preference. Drawing inferences from both avian bill proportions and variations in the dental morphology of extinct and extant taxa, we provide quantitative data to support the hypothesis that the Longipterygidae were animalivorous, with greater support for insectivory.

LncRNA HOTTIP impacts the proliferation and differentiation of fibroblast-like synoviocytes in ankylosing spondylitis through the microRNA-30b-3p/PGK1 axis

ObjectiveLong non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been reported to exert regulatory effects on biological processes. This study intended to assess the role of the lncRNA HOXA transcript at the distal tip (HOTTIP)/miR-30b-3p/phosphoglycerate kinase 1 (PGK1) axis in ankylosing spondylitis (AS).MethodsLevels of HOTTIP, miR-30b-3p and PGK1 in AS synovial tissues and cultured AS fibroblast-like synoviocytes (ASFLSs) were assessed. The ASFLSs were identified and, respectively, treated with altered expression of HOTTIP and miR-30b-3p, and then, the proliferation and differentiation of the ASFLSs were assessed. The AS mouse models were established by injection of proteoglycan and Freund’s complete adjuvant and then were treated with altered expression of HOTTIP and miR-30b-3p, and the pathological changes and apoptosis of synoviocytes in mice’ synovial tissues were measured. The relationship of HOTTIP, miR-30b-3p and PGK1 was verified.ResultsHOTTIP and PGK1 were elevated, while miR-30b-3p was reduced in AS synovial tissues and ASFLSs. Elevated miR-30b-3p or inhibited HOTTIP restrained proliferation and differentiation of ASFLSs and also improved the pathological changes and promoted apoptosis of synoviocytes in mice’s synovial tissues. PGK1 was a target of miR-30b-3p, and miR-30b-3p could directly bind to HOTTIP. Silencing miR-30b-3p or overexpressing PGK1 reversed the improvement of AS by knocking down HOTTIP or up-regulating miR-30b-3p.ConclusionOur study suggests that reduced HOTTIP ameliorates AS progression by suppressing the proliferation and differentiation of ASFLSs through the interaction of miR-30b-3p and PGK1.