Prospective, randomized, multicenter clinical study comparing a self-expanding covered stent to percutaneous transluminal angioplasty for treatment of upper extremity hemodialysis arteriovenous fistula stenosis

Use of a covered stent after percutaneous transluminal angioplasty (PTA) was compared to PTA alone for treatment of upper extremity hemodialysis patients with arteriovenous fistula (AVF) stenoses. Patients with AVF stenosis of 50% or more and evidence of AVF dysfunction underwent treatment with PTA followed by randomization of 142 patients to include a covered stent or 138 patients with PTA alone. Primary outcomes were 30-day safety, powered for noninferiority, and six-month target lesion primary patency (TLPP), powered to test whether TLPP after covered-stent placement was superior to PTA alone. Twelve-month TLPP and six-month access circuit primary patency (ACPP) were also hypothesis tested while additional clinical outcomes were observed through two years. Safety was significantly non-inferior while six- and 12-month TLPP were each superior for the covered stent group compared to PTA alone (six months: 78.7% versus 55.8%; 12 months: 47.9% versus 21.2%, respectively). ACPP was not statistically different between groups at six-months. Observed differences at 24 months favored the covered-stent group: 28.4% better TLPP, fewer target-lesion reinterventions (1.6 ± 1.6 versus 2.8 ± 2.0), and a longer mean time between target-lesion reinterventions (380.4 ± 249.5 versus 217.6 ± 158.4 days). Thus, our multicenter, prospective, randomized study of a covered stent used to treat AVF stenosis demonstrated noninferior safety with better TLPP and fewer target-lesion reinterventions than PTA alone through 24 months

Disseminated Cryptococcus Neoformans Infection in a Renal Transplant Patient

Background: Cryptoccocus Neoformans is a fungus mainly found in the environment that infects humans via inhalation and usually affects the lungs and central nervous system. Most people remain asymptomatic; however, immunocompromised patients are most susceptible to this pathogen, particularly HIV/AIDs patients. We present a case of a renal transplant patient with disseminated Cryptococcus Neoformans infection. Case Presentation: A 71 y/o female presents to the emergency department for further evaluation of a fever of unknown origin that has been going on for 6 days. Outpatient workup was initiated by the transplant service; however, due to persistently high fevers she was admitted for further workup and management. Patient reports that her fevers mainly occur at night and reach a maximum of 104-105 F. In the morning the fever decreases to 102 F with Tylenol. Denies any other significant symptoms, recent travel, sick contacts, alcohol, tobacco, or drug use. Past history is significant for CKD due to IgA nephropathy with renal transplant 2.5 years ago. Patient is currently on a chronic immunosuppressive regimen of Mycophenolate and Tacrolimus and infection prophylaxis with TMP-SMX and Valganciclovir. Upon admission, vitals were within normal limits and physical exam was unremarkable. Labs showed negative urinalysis, influenza, COVID-19, and rapid strep antigen test. Lactic acid, magnesium, coagulation studies, TSH, and troponin were all within normal limits. BUN was elevated at 32 and Creatinine at 1.8. White blood cell count was decreased at 2.8k, hemoglobin decreased at 10.9, and hematocrit decreased at 34.2. Chest X-ray showed nodular opacifications involving the right mid to upper lung, possibly masses or mass like infiltrates. Malignancy at this point was high on the differential. CT of the chest was then obtained, which revealed a right upper lobe mass and bilateral pulmonary lymph node involvement that was concerning for metastatic disease. On admission day 2, a CT guided lung biopsy was done. Preliminary reads were suggestive of fungal etiology and no malignancy with the final report of histoplasmosis, but clinical correlation was recommended. On day 5, Cryptococcus Antigen (Ag) titer was obtained and was elevated. On day 6, bronchoscopy with cultures using MALDI-TOF revealed Cryptococcus neoformans and no malignant cells. Given concomitant cytopenia, patient was started on treatment for disseminated Cryptococcal disease with ambisome and flucytosine. However, patient developed an AKI likely from ambisone, and the regimen was switched to PO Voriconazole BID. On day 10, patient was switched to high dose fluconazole. On day 12, repeat Cryptococcal Ag titers showed an increase from 1:40 to 1:320, which was concerning for a high fungal burden. Ambisone was added back on with the fluconazole; however, due to worsening renal function ambisome was held again. Ultimately, the patient wanted to go home and she was discharged on high dose fluconazole per infectious disease recommendation with PCP and transplant service outpatient follow up. Discussion: This case demonstrates that although lobar masses in the elderly can be highly suspicious for malignancy, rarer causes such as Cryptococcus Neoformans should be considered on the differential

Renal sympathetic nervous system and the effects of denervation on renal arteries

UA Open Access Publishing FundResistant hypertension is associated with chronic activation of the sympathetic nervous system resulting in various comorbidities. The prevalence of resistant hypertension is often under estimated due to various reasons. Activation of sympathetic nervous system at the renal- as well as systemic- level contributes to the increased level of catecholamines and resulting increase in the blood pressure. This increased activity was demonstrated by increased muscle sympathetic nerve activity and renal and total body noradrenaline spillover. Apart from the hypertension, it is hypothesized to be associated with insulin resistance, congestive heart failure and obstructive sleep apnea. Renal denervation is a novel procedure where the sympathetic afferent and efferent activity is reduced by various techniques and has been used successfully to treat drug-resistant hypertension improvement of various metabolic derangements. Renal denervation has the unique advantage of offering the denervation at the renal level, thus mitigating the systemic side effects. Renal denervation can be done by various techniques including radiofrequency ablation, ultrasound guided ablation and chemical ablation. Various trials evaluated the role of renal denervation in the management of resistant hypertension and have found promising results. More studies are underway to evaluate the role of renal denervation in patients presenting with resistant hypertension in different scenarios. Appropriate patient selection might be the key in determining the effectiveness of the procedure.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]