Accessory lacrimal gland secretion mimicking seidel positivity following complex cataract surgery: Case report.

Purpose: To describe the presentation of lacrimal gland secretions mimicking a positive Seidel test following combined complex cataract surgery and endocyclophotocoagulation (ECP). Observation: The patient presented with a posterior subcapsular cataract (PSC) most likely secondary to chronic steroid use for a history of chemical burns from a firework injury in 2019. This injury resulted in symblepharon formation and limbal stem cell deficiency. He also developed glaucoma secondary to steroid response and angle structure damage. On postoperative day 1 (POD 1) after combined cataract surgery and ECP, the patient's paracentesis was Seidel positive and aqueous suppression was started. On postoperative week 1 (POW 1), the paracentesis was Seidel negative; however, it was noted at this visit that there were 3 pinpoint areas in the superotemporal conjunctiva that were Seidel positive. Digital pressure did not worsen the leak. Ultrasound biomicroscopy (UBM) was performed at POW 2.5 and showed lacrimal gland ducts in the superotemporal conjunctiva. Given this, it is likely that the "Seidel positive" finding was not due to aqueous humor leakage, but secretions from lacrimal gland tissue that may have been dragged more anteriorly due to conjunctiva scarring, thus producing a false positive Seidel sign. Conclusion & importance: This case highlights a false positive Seidel sign in the context of an eye with a complex ocular history and recent surgery. Clinicians should recognize that a false positive Seidel sign is possible if normal lacrimal gland anatomy has been disturbed.

Rapid pacing and high-frequency jet ventilation additively improve catheter stability during atrial fibrillation ablation.

INTRODUCTION: Catheter stability during atrial fibrillation ablation is associated with higher ablation success rates. Rapid cardiac pacing and high-frequency jet ventilation (HFJV) independently improve catheter stability. Simultaneous modulation of cardiac and respiratory motion has not been previously studied. The objective of this study was to determine the effect of simultaneous heart rate and respiratory rate modulation on catheter stability. METHODS: Forty patients undergoing paroxysmal atrial fibrillation ablation received ablation lesions at 15 prespecified locations (12 left atria, 3 right atria). Patients were randomly assigned to undergo rapid atrial pacing for either the first or the second half of each lesion. Within each group, half of the patients received HFJV and the other half standard ventilation. Contact force and ablation data for all lesions were compared among the study groups. Standard deviation of contact force was the primary endpoint defined to examine contact force variability. RESULTS: Lesions with no pacing and standard ventilation had the greatest contact force standard deviation (5.86 ± 3.08 g), compared to lesions with pacing and standard ventilation (5.45 ± 3.28 g; P < .01) or to lesions with no pacing and HFJV (4.92 ± 3.00 g; P < .01). Lesions with both pacing and HFJV had the greatest reduction in contact force standard deviation (4.35 ± 2.81 g; P < .01), confirming an additive benefit of each maneuver. Pacing and HFJV together was also associated with a reduction in the proportion of lesions with excessive maximum contact force (P < .001). DISCUSSION: Rapid pacing and HFJV additively improve catheter stability. Simultaneous pacing with HFJV further improves catheter stability over pacing or HFJV alone to optimize ablation lesions.

Acute kidney injury in patients undergoing endovascular therapy for critical limb ischemia.

BACKGROUND: Similar to coronary angiography and interventions, patients undergoing percutaneous treatment of lower extremity peripheral arterial disease are also at risk of acute kidney injury (AKI). The incidence, risk factors associations, need for dialysis and inhospital mortality related to AKI in patients with critical limb ischemia (CLI) following endovascular therapy is poorly defined. OBJECTIVES: The purpose of this study was to analyze data from the National Inpatient Sample (NIS) to determine the aforementioned outcomes in patients with CLI. METHODS: Using the full NIS admission dataset from 2003 through 2012, ICD-9 codes relevant to comorbid conditions, procedure codes, composite codes for AKI, and inhospital mortality were analyzed using multivariate models. RESULTS: A total of 273,624 patients were included with a mean age of 70.0 ± 27.4 years, 46.0% were female, 57.2% had diabetes, 43.4% had coronary artery disease (CAD), and 29.2% had chronic kidney disease (CKD). The overall rate of AKI was 10.4%, and there was a temporal rise over the analysis period in AKI incidence (p < .001). Age, diabetes, CKD, and heart failure were all associated with AKI (p < .0001). The inhospital mortality rate in the patients with AKI declined over time but was higher than in patients without AKI (6.0% vs. 1.4%), p < .0001. The mortality rate was substantially higher in patients with AKI requiring dialysis as compared to AKI not requiring dialysis (13.4% vs. 5.6%), p < .0001. CONCLUSIONS: AKI is associated with age, CKD, and heart failure. The incidence of AKI following endovascular therapy for CLI is rising and independently associated with inhospital mortality.

Chondrogenic, hypertrophic, and osteochondral differentiation of human mesenchymal stem cells on three-dimensionally woven scaffolds.

The development of mechanically functional cartilage and bone tissue constructs of clinically relevant size, as well as their integration with native tissues, remains an important challenge for regenerative medicine. The objective of this study was to assess adult human mesenchymal stem cells (MSCs) in large, three-dimensionally woven poly(ε-caprolactone; PCL) scaffolds in proximity to viable bone, both in a nude rat subcutaneous pouch model and under simulated conditions in vitro. In Study I, various scaffold permutations-PCL alone, PCL-bone, "point-of-care" seeded MSC-PCL-bone, and chondrogenically precultured Ch-MSC-PCL-bone constructs-were implanted in a dorsal, ectopic pouch in a nude rat. After 8 weeks, only cells in the Ch-MSC-PCL constructs exhibited both chondrogenic and osteogenic gene expression profiles. Notably, although both tissue profiles were present, constructs that had been chondrogenically precultured prior to implantation showed a loss of glycosaminoglycan (GAG) as well as the presence of mineralization along with the formation of trabecula-like structures. In Study II of the study, the GAG loss and mineralization observed in Study I in vivo were recapitulated in vitro by the presence of either nearby bone or osteogenic culture medium additives but were prevented by a continued presence of chondrogenic medium additives. These data suggest conditions under which adult human stem cells in combination with polymer scaffolds synthesize functional and phenotypically distinct tissues based on the environmental conditions and highlight the potential influence that paracrine factors from adjacent bone may have on MSC fate, once implanted in vivo for chondral or osteochondral repair.

Utilization of a Radiation Safety Time-Out Reduces Radiation Exposure During Electrophysiology Procedures.

OBJECTIVES: This study sought to determine whether a radiation safety time-out reduces radiation exposure in electrophysiology procedures. BACKGROUND: Time-outs are integral to improving quality and safety. The authors hypothesized that a radiation safety time-out would reduce radiation exposure levels for patients and the health care team members. METHODS: The study was performed at the New York University Langone Health Electrophysiology Lab. Baseline data were collected for 6 months prior to the time-out. On implementation of the time-out, data were collected prospectively with analyses to be performed every 3 months. The primary endpoint was dose area product. The secondary endpoints included reference point dose, fluoroscopy time, use of additional shielding, and use of alternative imaging such as intracardiac and intravascular ultrasound. RESULTS: A total of 1,040 patient cases were included. The median dose area product prior to time-out was 18.7 Gy∙cm2, and the median during the time-out was 14.7 Gy∙cm2, representing a 21% reduction (p = 0.007). The median reference point dose prior to time-out was 163 mGy, and during the time-out was 122 mGy (p = 0.011). The use of sterile disposable protective shields and ultrasound imaging for access increased significantly during the time-out. CONCLUSIONS: A radiation safety time-out significantly reduces radiation exposure in electrophysiology procedures. Electrophysiology laboratories, as well as other areas of cardiovascular medicine using fluoroscopy, should strongly consider the use of radiation safety time-outs to reduce radiation exposure and improve safety.

Pacing Mediated Heart Rate Acceleration Improves Catheter Stability and Enhances Markers for Lesion Delivery in Human Atria During Atrial Fibrillation Ablation.

OBJECTIVES: This study sought to investigate the effect of pacing mediated heart rate modulation on catheter-tissue contact and impedance reduction during radiofrequency ablation in human atria during atrial fibrillation (AF) ablation. BACKGROUND: In AF ablation, improved catheter-tissue contact enhances lesion quality and acute pulmonary vein isolation rates. Previous studies demonstrate that catheter-tissue contact varies with ventricular contraction. The authors investigated the impact of modulating heart rate on the consistency of catheter-tissue contact and its effect on lesion quality. METHODS: Twenty patients undergoing paroxysmal AF ablation received ablation lesions at 15 pre-specified locations (12 left atria, 3 right atria). Patients were assigned randomly to undergo rapid atrial pacing for either the first half or the second half of each lesion. Contact force and ablation data with and without pacing were compared for each of the 300 ablation lesions. RESULTS: Compared with lesion delivery without pacing, pacing resulted in reduced contact force variability, as measured by contact force SD, range, maximum, minimum, and time within the pre-specified goal contact force range (p < 0.05). There was no difference in the mean contact force or force-time integral. Reduced contact force variability was associated with a 30% greater decrease in tissue impedance during ablation (p < 0.001). CONCLUSIONS: Pacing induced heart rate acceleration reduces catheter-tissue contact variability, increases the probability of achieving pre-specified catheter-tissue contact endpoints, and enhances impedance reduction during ablation. Modulating heart rate to improve catheter-tissue contact offers a new approach to optimize lesion quality in AF ablation. (The Physiological Effects of Pacing on Catheter Ablation Procedures to Treat Atrial Fibrillation [PEP AF]; NCT02766712).

Three-dimensional elastomeric scaffolds designed with cardiac-mimetic structural and mechanical features.

Tissue-engineered constructs, at the interface of material science, biology, engineering, and medicine, have the capacity to improve outcomes for cardiac patients by providing living cells and degradable biomaterials that can regenerate the native myocardium. With an ultimate goal of both delivering cells and providing mechanical support to the healing heart, we designed three-dimensional (3D) elastomeric scaffolds with (1) stiffnesses and anisotropy mimicking explanted myocardial specimens as predicted by finite-element (FE) modeling, (2) systematically varied combinations of rectangular pore pattern, pore aspect ratio, and strut width, and (3) structural features approaching tissue scale. Based on predicted mechanical properties, three scaffold designs were selected from eight candidates for fabrication from poly(glycerol sebacate) by micromolding from silicon wafers. Large 20×20 mm scaffolds with high aspect ratio features (5:1 strut height:strut width) were reproducibly cast, cured, and demolded at a relatively high throughput. Empirically measured mechanical properties demonstrated that scaffolds were cardiac mimetic and validated FE model predictions. Two-layered scaffolds providing fully interconnected pore networks were fabricated by layer-by-layer assembly. C2C12 myoblasts cultured on one-layered scaffolds exhibited specific patterns of cell elongation and interconnectivity that appeared to be guided by the scaffold pore pattern. Neonatal rat heart cells cultured on two-layered scaffolds for 1 week were contractile, both spontaneously and in response to electrical stimulation, and expressed sarcomeric α-actinin, a cardiac biomarker. This work not only demonstrated several scaffold designs that promoted functional assembly of rat heart cells, but also provided the foundation for further computational and empirical investigations of 3D elastomeric scaffolds for cardiac tissue engineering.

Chondrogenic priming adipose-mesenchymal stem cells for cartilage tissue regeneration.

PURPOSE: Chondrocytes lose their ability to produce cartilaginous matrix during multiplication in culture through repeated passages, resulting in inferior tissue phenotype. To overcome the limited amount of primary chondrocytes, we aimed to determine the optimal culture condition for in vitro/in vivo cartilage regeneration using human adipose-derived mesenchymal stem cells (AMSCs). METHODS: To evaluate the effects exerted by the chondrocytic culture condition on AMSC, we utilized chondrocyte conditioned medium (CM) and/or co-culture methods to prime and differentiate AMSCs. We evaluated ultimate in vivo engineered cartilage with primed AMSCs with that of chondrocytes. To examine the link between conditioned factors and proliferation/differentiation, cell cycle progression of AMSCs were examined using 5-ethynyl-2'-deoxyuridine (EdU), and gene expression was monitored. RESULTS: We report that AMSCs can be stimulated to become chondrogenic cells when expanded with chondrocyte CM. Polymeric scaffolds co-seeded with CM- expanded AMSCs and primary chondrocytes resulted in in vivo cartilaginous tissues with similar biochemical content to constructs seeded with chondrocytes alone. CONCLUSION: These results indicate that chondrocyte CM consists of suitable morphogenetic factors that induce the chondrogenic priming of AMSCs for cartilage tissue engineering.

Computer-guided implant rehabilitation of an edentulous patient.

Computer-guided implant treatment is one of the popular options in the rehabilitation of dentitions in the edentulous situation. Patients should benefit not only from the advent of precise implant installation, but also the possibility of restoration of function and aesthetics immediately after the treatment. This poster presentation illustrated, from the view of the prosthodontist, the procedures and precautions involved using a clinical case as an example.