Outcomes of operative intervention for ulcers over hemodialysis arteriovenous access.

INTRODUCTION: The native arteriovenous fistula (AVF) is the gold standard for long-term hemodialysis access. When native vein options are exhausted, arteriovenous graft (AVG) becomes the next choice. An ulcer over an AVF or AVG is a serious condition with the potential for life-threatening hemorrhage. OBJECTIVES: This study aims to present our experience with surgical management of ulcers over AVFs or AVGs. MATERIALS AND METHODS: Electronic records of 26 patients who underwent 27 consecutive surgical procedures for ulcers over AVFs or AVGs from December 31, 2016 to December 31, 2021 at the Royal Liverpool University Hospital were retrospectively analyzed. RESULTS: The majority were males (14/26, 53.8%) and the median age was 64.5 years. Operative repair was required for 25 ulcers over 24 AVFs and 2 ulcers over 2 AVGs. Ten patients (37%) presented with bleeding. Seventeen (63%) had impending bleeding suggested by a thin soft tissue covering or a false aneurysm at the site of the ulcer. Previous endovascular intervention for fistula outflow stenosis was a significant predictor for presenting with bleeding (p = 0.031). All ulcers (27/27, 100%) underwent excision and primary skin closure. Fistula wall defects were directly repaired in 18/27 (66.7%). Four/26 (14.8%) fistulas had to be ligated and 2 (7.4%) had end-to-end re-anastomosis after excision of damaged segments. Three/26 (11.53%) fistulas thrombosed immediately after the intervention. The overall fistula salvage rate was 73.08% (19/26). There was 1 (3.7%) patient mortality due to bleeding from wound breakdown after surgery. CONCLUSIONS: An acceptable fistula salvage rate can be expected following surgical repair of ulcers over AVFs and AVGs. A history of previous endovascular interventions for fistula outflow stenosis was a predictor of bleeding from these ulcers.

[DDQM][HSO4]/TBHP as a Multifunctional Catalyst for the Metal Free Tandem Oxidative Synthesis of 2-Phenylquinazolin-4(3H)-ones.

A bifunctional ionic liquid (IL) [DDQM][HSO4] has been designed and explored as a three-way catalyst for the synthesis of 2-phenylquinazolin-4(3H)-ones from anthranilamide and benzyl alcohol in 3.5 min incorporating microwave irradiation. Photochemically the reaction proceeds for 4 h at room temperature and thermally for 8 h at 120 °C. Further IL-assisted metal, solvent, and base free in situ oxidation of benzyl alcohols to aldehydes shows its task specificity. The multifunctionality of the IL was reestablished with the synthesis of two Wnt pathway antagonists.

Outcomes of Nonstandard Donor Kidney Transplants in Recipients Aged 70 Years or More: A Single-Center Experience.

OBJECTIVES: There is a global increase in the prevalence of end-stage kidney disease among the elderly. As a result, more elderly recipients are being considered for kidney transplants. Because of the scarcity of donor organs, such patients are more likely to receive transplants from nonstandard donor kidneys.Here, we examined the outcomes of kidney transplants with a nonstandard donor allograftin recipients ≥70 years of age. MATERIALS AND METHODS: Records of patients who received transplants at a single UK centerfrom April 1, 2015, through March 31, 2021, were retrospectively analyzed to identify those who were ≥70 years old at the time of surgery. Outcomes ofthose who received a kidney transplantfrom a nonstandard donor (group 1) were compared to those who received a kidney transplant from a standard criteria donor or living donor (group 2). RESULTS: During the study period, of 670 kidney transplant procedures, 67 recipients (10%) were ≥70 years of age at the time of surgery, with 54 (80.6%) identified in group 1 and 13 (19.4%) identified in group 2. Cold ischemia time (P = .001) and incidence of delayed graft function (P = .044) were significantly higherin group 1. Duration of graft survival atthe end of follow-up was not different between the groups (log rank = 0.218), butthe mean serum creatinine values at 2 years (P = .016) and 3 years (P = .048) years were significantly higherin group 1. Patients in group 1 had shorter survival time (log rank = 0.037). CONCLUSIONS: Nonstandard donor kidneys should be used cautiously in elderly recipients as patient survival was shown to be comparatively poor compared with elderly recipients who received a kidney transplant from a standard criteria donor or a living donor.

Kidney Transplantation From Deceased Donors With Vaccine-induced Immune Thrombocytopenia and Thrombosis: An Updated Analysis of the UK Experience.

BACKGROUND: The emergence and attendant mortality of vaccine-induced immune thrombocytopenia and thrombosis (VITT) as a consequence of vaccination against severe acute respiratory syndrome coronavirus 2 have resulted in some patients with VITT being considered as deceased organ donors. Outcomes after kidney transplantation in this context are poorly described. Because the disease seems to be mediated by antiplatelet factor 4 antibodies, there is a theoretical risk of transmission via passenger leukocytes within the allograft. METHODS: We analyzed the experience of kidney transplantation from donors with VITT in the United Kingdom between January and June 2021. We followed-up all recipients of kidney-only transplants from donors with VITT to detect major postoperative complications or features of disease transmission and assess graft survival and function. RESULTS: There were 16 kidney donors and 30 single kidney transplant recipients in our study period. Of 11 preimplantation biopsies, 4 showed widespread glomerular microthrombi. After a median of 5 mo, patient and graft survival were 97% and 90%, respectively. The median 3-mo estimated glomerular filtration rate was 51 mL/min/1.73 m 2 . Two recipients had detectable antiplatelet factor 4 antibodies but no evidence of clinical disease after transplantation. Major hemorrhagic complications occurred in 3 recipients, all of whom had independent risk factors for bleeding, resulting in the loss of 2 grafts. The involvement of VITT could not be completely excluded in one of these cases. CONCLUSIONS: The UK experience to date shows that favorable outcomes are possible after kidney transplantation from donors with VITT but highlights the need for ongoing vigilance for donor-related complications in these patients.

Endovascular Treatment for Transplant Renal Artery Stenosis Improves the Short- and Long-Term Graft and Patient Outcomes.

OBJECTIVES: Transplant renal artery stenosis is the commonest vascular complication after kidney transplant. This study aimed to evaluate the efficacy of endovascular treatment for patients with clinically significant transplant renal artery stenosis. MATERIALS AND METHODS: Electronic patient records of kidney transplant recipients who received transplants from October 1, 2010, to July 31, 2021, at the Royal Liverpool University Hospital were retrospectively reviewedtoidentify thosewhounderwent endovascular treatment for transplant renal artery stenosis. Analysis of variance and paired sample t tests were respectively used to compare serum creatinine and the mean number of antihypertensive medications before and aftertreatment. RESULTS: During the period of analysis, there were 1211 kidney transplant recipients, with 33 (2.72%) who received endovascular treatment for transplant renal artery stenosis. Mostofthesepatientsweremen(25/33), and the median age was 59 years (range, 27-83 y). The mean follow-up duration was 69.82 months. As primary treatment, 19/33 patients (57.6%) were treated with percutaneous balloon angioplasty and 14/33 (42.4%) received stents. Procedure-related complications occurred in 3 patients (9.1%; 2 had false aneurysms, 1 had renal artery dissection). Significant improvements in mean serum creatinine levels were shown up to 4 years after the procedure (P = .019). A significant difference in the mean number of antihypertensive drugs before and after treatment was noted in those who had resistant hypertension as a presentation for transplantrenal artery stenosis (P = .016). At the end of follow-up, 7 patients (21.1%) had graft failure, with 1 patient (3.0%) having graft failure as a direct consequence of transplant renal artery stenosis. There was no reported incidence of patient mortality. CONCLUSIONS: Endovascular treatment for transplant renal artery stenosis provides a sustained improvement in graft function and a significant reduction in antihypertensive drug requirement.

Ionic Liquid-Based Colloidal Formulations for the Synthesis of Nano-MOFs: Applications in Gas Adsorption and Water Desalination.

Microemulsions (MEs) comprising choline dioctylsulfosuccinate [Cho][AOT], a biobased ionic liquid (IL) surfactant as an emulsifier, (R)-(+)-limonene (RL) as a nonpolar phase, and ethylene glycol (EG)/ethanolammonium formate (EOAF) as an organic solvent/low-viscosity IL polar component were constructed. Spontaneous aggregation of [Cho][AOT] was observed with a negative ΔH form using isothermal titration calorimetry. The aggregates of [Cho][AOT] in RL showed a critical micellar concentration (cmc) of ∼5.49 mM, EG (cmc ∼3.99 mM), and EOAF (cmc ∼1.56 mM), and these are further characterized by various techniques. These novel IL-based MEs have been used as nanoreactors for the sustainable synthesis of uniform nanosized metal-organic frameworks (N-MOFs), such as MIL-53(Al), HKUST-1, UIO-66-NH2, and ZIF-8, with a precise control over size and morphology at room temperature. Characterization of N-MOFs has been performed using scanning electron microscopy, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The synthesized N-MOFs have been used to prepare stable and uniform thin film nanocomposite nanofiltration membranes, suitable for desalination of brackish water with excellent flux (31.8 LMH/bar) and rejection (99.0%) of divalent salts.

Investigating the relationship between class I HLA-specific immunoglobulin-G subclasses, Pan-IgG single antigen bead assays and complement mediated interference in sera from renal transplant recipients.

INTRODUCTION: Antibody mediated rejection is the leading cause of kidney transplant failure. Not all antibodies are harmful and some may be protective. Immunoglulin Gs, of which there are four subtypes, are detected by single antigen bead testing. The aims of this study were to characterise the IgG subclass profiles for class I HLA-specific antibodies in an uncensored post-transplant population and to determine the underlying relationship between reactivity patterns and MFI cut-offs with the pan-IgG assay. METHODS: Patients were recruited to the study who were transplanted in our centre between 2009 and 2014. Prospectively stored post-transplant serum initially underwent a Labscreen Mixed assay and those positive for class I HLA-specific antibody underwent standard SAB testing, EDTA, 1 in 10 dilution and IgG subclass modifications using the Luminex platform. A total of 4947 bead reactions from 51 patients were analysed. RESULTS: A 1 in 10 dilution was used as a comparator pan-IgG assay for summed subclass and individual subclass linear regression analyses. Using a dilution to standard assay ratio we characterised all reactions for prozone potential i.e. how likely there is to be inhibition related to complement complex formation. We stratified samples into degrees of association and were able to determine suggested MFI thresholds of Log 5.35 for the dilution assay and Log 5.05 for the summed subclass assay when considering a Log MFI of 6.9 (1000) in the standard assay. Using individual subclass dominant reactions (>70%) we were able to determine linear relationships between the 1 in 10 dilution pan-IgG assay and the individual subclass assays (excluding prozone potential reactions for IgG1/3) enabling us to suggest Log MFI thresholds of 5.03, 3.58, 4.3 and 4.05 respectively for IgG1-4. DISCUSSION: We recommend a 1 in 10 dilution as the optimum pan-IgG comparator assay for a subclass analysis. We advocate the utilisation of the summed subclass assay to determine overall relationships and potential subclass failures. Following others, we recommend serum pre-treatment of the subclass assays to mitigate prozone. We suggest cut-offs for each IgG subclass which should be used with caution given the many inhibitory influences which may include competitive inhibition for bead binding, IgM and IgA interference and under-representation of specific subclasses on the bead panel.

Investigating complement mediated interference in class I HLA-specific antibodies following renal transplantation.

INTRODUCTION: Single antigen bead testing (SAB) for HLA-specific antibody enables efficient organ allocation and aids in the diagnosis of antibody mediated rejection. In this retrospective cohort study, a population of kidney transplant recipients possessing HLA Class I antibodies was used to evaluate the best method for resolving complement interference, the so called "prozone" effect. The aim was to compare the use of EDTA versus a Biotin-Streptavidin Complex as methodological approaches for abating the prozone effect using a fixed 1 in 10 dilution as validation. METHODS: One hundred and seventeen patients transplanted in our centre between 2009 and 2014 were identified as having class I HLA-specific antibody(-ies) using a Labscreen® Mixed assay. Positive sera underwent class I HLA-specific SAB testing; for comparison a standard SAB with and without EDTA, BSC and dilution (1 in 10) modifications were utilised. Samples were processed on the Luminex platform generating 11,349 bead reactions for analysis. RESULTS: We identified sera from 23 patients giving rise to 170 bead reactions showing complement interference. Using linear modelling, we observed slightly higher MFIs on average in both EDTA and BSC modifications when compared to the standard assay, allowing the nominal threshold MFI of 2000 in the standard assay to be adjusted to 2097 and 2033 in the EDTA and BSC assays respectively. We calculated 99% prediction intervals to establish outlier bead reactions for each assay. The 1 in 10 dilution was used as a crosscheck for determining which prozone reactions were overcome by EDTA and BSC. Using ROC curve analysis, EDTA was found to be ~90% sensitive and 100% specific compared to BSC which was ~60% sensitive and 100% specific in ameliorating prozone positive reactions at the thresholds defined by linear models. DISCUSSION: Our data indicates that both EDTA and BSC are suitable assays in overcoming CMI. We recommend that all clinical laboratories adopt a validated assay designed specifically to abrogate CMI for all potential renal transplant recipients, as the standard assay is inhibited in nearly 20% of a post-transplant cohort.

Versatile surface-active ionic liquid: construction of microemulsions and their applications in light harvesting.

This article outlines a sustainable method towards the synthesis of advanced materials such as core/shell Quantum Dots (QDs) and their in situ stabilization using microemulsions (MEs). QDs are versatile materials which show unusual optical properties. We have constructed MEs consisting of an Ionic Liquid (IL) based surfactant i.e. choline dioctylsulfosuccinate, [Cho][AOT] as an emulsifier, toluene as a nonpolar phase and water as a polar phase. The system forms a large single-phase region in the phase diagram without any co-surfactant. Spontaneous formation of micelles has been observed and studied through tensiometry and fluorescence and isothermal titration calorimetry (ITC). The exceptional swelling behaviour of the MEs was studied using Dynamic Light Scattering (DLS) and small angle neutron scattering (SANS). In ME droplets, i.e. Reverse Micelles (RMs), we successfully synthesized spherical core/shell QDs (size ∼3 to ∼6 nm) with precise control over the size and morphology. The QDs have been characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Powder X-ray Diffraction (PXRD). QDs stabilized in MEs exhibited excellent optical properties and can be suitably used as light harvesting materials for diverse applications.

Vascular Complications of Percutaneous Transradial Cardiac Catheterization.

The percutaneous transradial approach for coronary angiography and percutaneous coronary intervention is increasing in the United States. Although its vascular safety profile is better than the traditional femoral approach, it is important to learn about potential complications. In this article, we present two cases of vascular complications, namely, pseudoaneurysm and radial artery occlusion, after transradial cardiac catheterization, along with a review of the relevant literature.

Doble problema: fibrilación auricular y taquicardia ventricular simultánea / Double trouble: Concurrent atrial fibrillation and ventricular tachycardia

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Implantable Cardioverter-Defibrillator Shock after Stenting Across the Device Leads.

A 45-year-old man with nonischemic cardiomyopathy and end-stage renal disease had lived uneventfully with a cardiac resynchronization therapy defibrillator (CRT-D) for 5 years. Less than a month before presenting at our institution, he had undergone stenting of his partially occluded subclavian vein, to relieve stenosis of the ipsilateral arteriovenous fistula that was used for his hemodialysis. The CRT-D subsequently discharged. Device interrogation revealed that electrical noise originating from leads damaged by the stent had caused the inappropriate shock and intermittent electrical discharges thereafter. The patient was highly traumatized by these events and insisted upon device removal, which deprived him of a potentially life-saving intervention. He later had a cardiac arrest that resulted in sustained profound hypoxic ischemic encephalopathy with minimal neurologic recovery: his family placed him in a long-term care facility on ventilator support, with a tracheostomy and feeding tube. This situation might have been avoided through collaboration between the interventional radiologist and the electrophysiologist. To our knowledge, this is the first report of a patient with nonischemic cardiomyopathy and end-stage renal disease who presented with inappropriate defibrillator discharge caused by lead damage secondary to stenting across the leads.

Horseshoe thrombus in a patient with mechanical prosthetic mitral valve: A case report and review of literature.

Patients with prosthetic cardiac valves are at high risk for thromboembolic complications and need life long anticoagulation with warfarin, which can be associated with variable dose requirements and fluctuating level of systemic anticoagulation and may predispose to thromboembolic and or hemorrhagic complications. Prosthetic cardiac valve thrombosis is associated with high morbidity and mortality. A high index of suspicion is essential for prompt diagnosis. Transthoracic echocardiography, and if required transesophageal echocardiography are the main diagnostic imaging modalities. Medically stable patients can be managed with thrombolytic therapy and anticoagulation, while some patients may require surgical thrombectomy or valve replacement. We present a case report of a patient with prosthetic mitral valve and an unusually large left atrial thrombus with both thromboembolic and hemorrhagic complications.

Left ventricular pseudoaneurysm: A case report and review of the literature.

Left ventricular (LV) pseudoaneurysm is a rare complication that is reported in less than 0.1% of all patients with myocardial infarction. It is the result of cardiac rupture contained by the pericardium and is characterized by the absence of myocardial tissue in its wall unlike true aneurysm which involves full thickness of the cardiac wall. The clinical presentation of these patients is nonspecific, making the diagnosis challenging. Transthoracic echocardiogram and cardiac magnetic resonance imaging are the noninvasive modalities whereas coronary arteriography and left ventriculography are invasive modalities used for the diagnosis. As this condition is lethal, prompt diagnosis and timely management is vital.

Potential for improved glycemic control with dietary Momordica charantia in patients with insulin resistance and pre-diabetes.

Bitter Melon (Momordica charantia) is a widely used traditional remedy for hyperglycemia. While the medicinal properties of this plant have been studied extensively using in vitro and animal models, the clinical efficacy and safety in humans is largely unknown. This review discusses the benefits and limitations of bitter melon supplementation in the context of epidemic levels of insulin resistance and pre-diabetes throughout the world.