Relevance of Proteinuria in Kidney Transplant Recipients and Allograft Outcomes.

BACKGROUND: The onset of proteinuria in renal allograft recipients is frequently associated with an increased risk for both graft failure and mortality. We investigated the risk associated with post-transplant proteinuria and its time-dynamics in a select group treated for biopsy proven antibody-mediated rejection (ABMR). METHODS: Eighty-five patients who underwent transplantation were enrolled in our study and followed up from transplantation until October 31, 2020, death, or the date of the return to dialysis. We created two main groups: the ABMR group (n = 19) and an ABMR-negative control group with stable kidney function (n = 52) without donor-specific antibodies (DSA) and a subgroup with DSAs but stable graft function (n = 14) without ABMR. Differences in patient, donor, and transplant graft characteristics between the groups were assessed by Fisher's exact test for categorical variables. Death-censored graft loss was evaluated with the help of Kaplan-Meier analysis using log risk statistics. RESULTS: Proteinuria decreased after treatment in the ABMR group (P < .0009). Pre-treatment every 10 mg/mmol increase in proteinuria was associated with a 7% increase in the risk for graft failure in the ABMR group. The estimated 3-year graft survival was 87.5% in the ABMR group, compared to 93% in the group without ABMR but with pre-formed DSA, and 100% in the DSA negative subgroup (log-rank probe P < .0666). CONCLUSION: Proteinuria is an independent predictor for graft failure, can be lowered by treatment for ABMR but ABMR is associated with lower graft survival in our study population.

Hemorrhagic Pneumonia in a Kidney Transplant Recipient Caused by Stenotrophomonas Maltophilia Infection: A Case Report.

Pneumonia is a common nosocomial complication in transplant patients. Stenotrophomonas maltophilia is recognized as a common cause and is typically seen in immunocompromised and critically ill patients. S. maltophilia, a nonfermenting gram-negative rod, ranks as the third most common nosocomial pathogen, following Pseudomonas aeruginosa and Acinetobacter. The bacteria are frequently found in environmental sources and are prevalent in healthcare facilities, including in tap water faucets, shower outlets, air-cooling systems, intravenous fluids, catheters, dialysis machines, and oxygen humidifiers. This bacterium possesses the ability to rapidly form biofilms, enabling it to colonize new surfaces in less than 24 hours. While S. maltophilia generally exhibits low virulence, there remains uncertainty among many clinicians regarding whether it is merely a colonizer or the primary cause of infection. Although S. maltophilia infections are rare in immunocompetent individuals, the species is increasingly recognized as an opportunistic pathogen in vulnerable populations such as those with cystic fibrosis, cancer, and other conditions leading to immunosuppression. S. maltophilia now recognized as a causative agent in various clinical syndromes, primarily affecting the lungs and bloodstream. We present a case of S. maltophilia-associated lung infection in a kidney transplant recipient, emphasizing the significance of underlying diseases and associated signs and symptoms.

Effect of education on sun-safe behaviour in kidney transplant recipients.

BACKGROUND: Organ transplant recipients (OTR) are more likely to develop skin cancer than the general population. One of the main components of the exposome that triggers the development of skin tumours is solar ultraviolet (UV) radiation. To reduce the incidence of harmful consequences of sun exposure, sun protection education is needed for patients taking long-term immunosuppressive drugs. METHODS: In a previous study, we assessed the sun-safe behaviour of 221 OTR using a questionnaire before and after transplantation and personally educated the patients about proper sun protection. After the education, there were no further reminder presentations. Presently, the sun protection and sun seeking habits of the available 176 of these patients were questioned to assess the long-term effect of the previous sun protection education. RESULTS: Two-four years after the education, more patients wore hats and protected their skin with long-sleeved clothing than before the education. In terms of sun seeking habits, both occupational and recreational sun exposure decreased significantly. Significantly fewer people went on holiday after transplantation, but those who went on holiday spent significantly less time in the sun. CONCLUSION: The long-term positive effects of education can be seen both in the patients' sun protection and in their sun seeking habits. However, the long-term goal is to maintain these results and thereby reduce the likelihood of skin tumours and consequently the associated tumour death.

Rescue Allocation Modes in Eurotransplant Kidney Transplantation: Recipient Oriented Extended Allocation Versus Competitive Rescue Allocation-A Retrospective Multicenter Outcome Analysis.

BACKGROUND: Whenever the kidney standard allocation (SA) algorithms according to the Eurotransplant (ET) Kidney Allocation System or the Eurotransplant Senior Program fail, rescue allocation (RA) is initiated. There are 2 procedurally different modes of RA: recipient oriented extended allocation (REAL) and competitive rescue allocation (CRA). The objective of this study was to evaluate the association of patient survival and graft failure with RA mode and whether or not it varied across the different ET countries. METHODS: The ET database was retrospectively analyzed for donor and recipient clinical and demographic characteristics in association with graft outcomes of deceased donor renal transplantation (DDRT) across all ET countries and centers from 2014 to 2021 using Cox proportional hazards methods. RESULTS: Seventeen thousand six hundred seventy-nine renal transplantations were included (SA 15 658 [89%], REAL 860 [4.9%], and CRA 1161 [6.6%]). In CRA, donors were older, cold ischemia times were longer, and HLA matches were worse in comparison with REAL and especially SA. Multivariable analyses showed comparable graft and recipient survival between SA and REAL; however, CRA was associated with shorter graft survival. Germany performed 76% of all DDRTs after REAL and CRA and the latter mode reduced waiting times by up to 2.9 y. CONCLUSIONS: REAL and CRA are used differently in the ET countries according to national donor rates. Both RA schemes optimize graft utilization, lead to acceptable outcomes, and help to stabilize national DDRT programs, especially in Germany.

Dynamic Perfusion Computed Tomography for the Assessment of Concomitant Coronary Artery Disease in Patients with a History of Percutaneous Transluminal Angioplasty for Chronic Limb-Threatening Ischemia-A Pilot Study.

BACKGROUND: Chronic limb-threatening ischemia (CLTI) is associated with high rates of long-term cardiovascular mortality. Exercise stress testing to detect obstructive coronary artery disease (CAD) can be difficult in this subset of patients due to inability to undergo exercise testing, presence of balanced ischemia and severe coronary artery calcification (CAC). AIM: To test the feasibility of regadenoson stress dynamic perfusion computed tomography (DPCT) in CLTI patients. METHODS: Between 2018 and 2023, coronary computed tomography angiography (CTA) and, in the case of a calcium score higher than 400, DPCT, were performed in 25 CLTI patients with a history of endovascular revascularization. RESULTS: Of the 25 patients, 19 had a calcium score higher than 400, requiring DPCT image acquisition. Obstructive CAD could be ruled out in 10 of the 25 patients. Of the 15 CTA/DPCT+ patients, 13 proceeded to coronary angiography (CAG). Revascularization was necessary in all 13 patients. In these 13 patients, vessel-based sensitivity and specificity of coronary CTA/DPCT as compared to invasive evaluation was 75%, respectively. At follow-up (27 ± 21 months) there was no statistically significant difference in all-cause mortality between CTA/DPCT- positive and -negative patients (p = 0.065). CONCLUSIONS: Despite a high prevalence of severe CAC, coronary CTA complemented by DPCT may be a feasible method to detect obstructive and functionally significant CAD in CLTI patients.

Assessment of amino-terminal C-type natriuretic peptide serum level and its correlation with high-density lipoprotein structure and function in patients with end stage renal disease before and after kidney transplantation.

We aimed to investigate serum amino-terminal C-type natriuretic peptide (NT-proCNP) and its relationship with quantitative and qualitative HDL-parameters in patients with end-stage renal disease (ESRD) before, then 1 and 6 months after kidney transplantation (TX). Seventy patients (47 males, 23 females, mean age 51.7 ± 12.4 years) were enrolled in a prospective follow-up study. We examined serum creatinine, C-reactive protein, procalcitonin, fasting glucose and lipid parameters before, then 1 and 6 months after TX. High-density lipoprotein- (HDL)-associated paraoxonase-1 (PON1) paraoxonase and arylesterase activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. NT-proCNP and oxidized low-density lipoprotein (oxLDL) levels were measured by ELISA. Mean NT-proCNP was 45.8 ± 21.9 pmol/L before renal transplantation and decreased markedly 1 month and 6 months after transplantation (5.3 ± 2.5 and 7.7 ± 4.9 pmol/L, respectively, P = 1 × 10-4). During the 6 months' follow-up, PON1 arylesterase, paraoxonase and salt-stimulated paraoxonase activities improved. NT-proCNP positively correlated with procalcitonin and creatinine and negatively with GFR, LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C). There was a negative correlation between serum NT-proCNP and PON1 arylesterase activity. According to the multiple regression analysis, the best predicting variables of NT-proCNP were serum procalcitonin, creatinine and PON1 arylesterase activity. NT-proCNP might be a novel link between HDL dysfunction and impaired vascular function in ESRD, but not after kidney transplantation. Further studies in larger populations are needed to clarify the exact role of NT-proCNP in the risk prediction for cardiovascular comorbidities and complications in ESRD.

Elucidation of the binding mode of organic polysulfides on the human TRPA1 receptor.

Introduction: Previous studies have established that endogenous inorganic polysulfides have significant biological actions activating the Transient Receptor Potential Ankyrin 1 (TRPA1) receptor. Organic polysulfides exert similar effects, but they are much more stable molecules, therefore these compounds are more suitable as drugs. In this study, we aimed to better understand the mechanism of action of organic polysulfides by identification of their binding site on the TRPA1 receptor. Methods: Polysulfides can readily interact with the thiol side chain of the cysteine residues of the protein. To investigate their role in the TRPA1 activation, we replaced several cysteine residues by alanine via site-directed mutagenesis. We searched for TRPA1 mutant variants with decreased or lost activating effect of the polysulfides, but with other functions remaining intact (such as the effects of non-electrophilic agonists and antagonists). The binding properties of the mutant receptors were analyzed by in silico molecular docking. Functional changes were tested by in vitro methods: calcium sensitive fluorescent flow cytometry, whole-cell patch-clamp and radioactive calcium-45 liquid scintillation counting. Results: The cysteines forming the conventional binding site of electrophilic agonists, namely C621, C641 and C665 also bind the organic polysulfides, with the key role of C621. However, only their combined mutation abolished completely the organic polysulfide-induced activation of the receptor. Discussion: Since previous papers provided evidence that organic polysulfides exert analgesic and anti-inflammatory actions in different in vivo animal models, we anticipate that the development of TRPA1-targeted, organic polysulfide-based drugs will be promoted by this identification of the binding site.

Radiation Exposure Reduction by Digital Variance Angiography in Lower Limb Angiography: A Randomized Controlled Trial.

BACKGROUND: digital variance angiography (DVA) provides higher image quality than digital subtraction angiography (DSA). This study investigates whether the quality reserve of DVA allows for radiation dose reduction during lower limb angiography (LLA), and compares the performance of two DVA algorithms. METHODS: this prospective block-randomized controlled study enrolled 114 peripheral arterial disease patients undergoing LLA into normal dose (ND, 1.2 µGy/frame, n = 57) or low-dose (LD, 0.36 µGy/frame, n = 57) groups. DSA images were generated in both groups, DVA1 and DVA2 images were generated in the LD group. Total and DSA-related radiation dose area product (DAP) were analyzed. Image quality was assessed on a 5-grade Likert scale by six readers. RESULTS: the total and DSA-related DAP were reduced by 38% and 61% in the LD group. The overall visual evaluation scores (median (IQR)) of LD-DSA (3.50 (1.17)) were significantly lower than the ND-DSA scores (3.83 (1.00), p < 0.001). There was no difference between ND-DSA and LD-DVA1 (3.83 (1.17)), but the LD-DVA2 scores were significantly higher (4.00 (0.83), p < 0.01). The difference between LD-DVA2 and LD-DVA1 was also significant (p < 0.001). CONCLUSIONS: DVA significantly reduced the total and DSA-related radiation dose in LLA, without affecting the image quality. LD-DVA2 images outperformed LD-DVA1, therefore DVA2 might be especially beneficial in lower limb interventions.

The Prognostic Role of CYP Enzyme in Kidney Transplantation: A Single Centre Experience.

BACKGROUND: The main goal of immunosuppressive agents is to reach a balance of preserving allograft function while minimizing adverse effects. The purpose of our research is to corroborate the role of CYP3A enzyme in developing individual medication therapy via measuring medicine levels in patients' blood samples. METHODS: This retrospective analysis studies 15 kidney transplant recipients. We carried out genotyping (CYP3A5, CYP3A4) after isolating DNA and RNA in patient and donor blood samples; we also determined CYP3A4 messenger RNA expression in case of recipients. Tacrolimus blood levels, dosage, and tacrolimus concentration normalized by dose and the body weight (C0/D ratio) were evaluated. RESULTS: In this research, recipients were divided into 2 groups based on their CYP3A5 genotype. Those who carry CYP3A5*1 allele (*1/*1 or *1/*3) are CYP3A5 expressors, whereas those who are homozygous for the nonfunctional CYP3A5*3 allele are CYP3A5 nonexpressors. There were 3 patients with functioning CYP3A5 enzyme (patients with CYP3A5*1/*3 genotype) where increased tacrolimus metabolism was expected. Our data show that C0/D ratio of CYP3A5 nonexpressors was around 3 times higher than of CYP3A5 expressors. Looking at CYP3A4 enzyme, we found 1 patient carried CYP3A4*22/*22 genotype where we expected decreased CYP3A4 expression. It is clear that this patient had adequate therapy medication levels (9.50 µg/L) despite having received very low dosage of tacrolimus (0.03 mg/weight/d). CONCLUSIONS: Our results confirmed the importance of determining CYP status of recipients after a transplant because individual differences were observed in tacrolimus treatment that were partly influenced by CYP status of recipients.

Ureteral Complications Requiring Intervention After Kidney Transplant: A Single-Center Experience.

The surgical aspect of kidney transplant can be the surgical technique itself or the use of reconstruction techniques in the case of a complication requiring reoperation. In our study, we examined particularly surgical techniques and reconstruction options for ureteral anastomoses. Data from patients who underwent kidney transplant from 2010 to 2020 (N = 433) were examined retrospectively at follow-up of at least 1 year. We sought an association between the type of ureteral anastomoses and parameters considered to be risk factors based on literature data. We did not note the complicated cases that solved spontaneously and only selected cases where the ureteral anastomosis complication (UAcomp) needed urologic, radiological, or surgical intervention. In a smaller group, we examined the correlation between BK polyomavirus and ureteral stenosis. A total of 9.2% (n = 40) of patients developed UAcomp, 67.5% (n = 27) of whom required reoperation. In complicated cases, the rate of primary ureteral anastomosis type was 60.0% (n = 24) ureteroneocystostomy (UNS) and 40.0% (n = 16) ureteroureterostomy (UU) (P = .184). After UNS, 7.7% (n = 17) of cases required reoperation, and this rate was 4.7% (n = 10) after UU (P = .164). After treatment of the UAcomp, 95.0% (n = 38) of the patients were discharged with a functioning graft, and 5.0% (n = 2) required graftectomy. Complications of ureteral anastomosis with appropriate interventions results in good graft function. The type of ureteral anastomosis is not significantly associated with UAcomp. It is important that the operating surgeon is well versed in UNS and UU techniques to be able to adapt to any situation, be it primary surgery or reoperation.

Investigation of Circulating MicroRNA Levels in Antibody-Mediated Rejection After Kidney Transplantation.

BACKGROUND: One of the most important possible complications determining long-term graft survival after kidney transplant is antibody-mediated rejection (ABMR). The criterion standard approach to recognize ABMR is currently the kidney biopsy with histopathologic analysis. However, this test has limitations because of difficulties in timing of sampling, the evaluability of histology because of the questionable representativeness of specimens, and the limited number of this intervention. Hence, new reliable, noninvasive biomarkers are required to detect the development of ABMR in time. METHODS: In this study, we analyzed the clinical data of 45 kidney transplant patients (mean age of 44.51 years, 20 male and 25 female subjects). These participants were recruited into 5 subcohorts based on their clinical status, histologic findings, and level of donor-specific anti-HLA antibodies. Circulating microRNAs (miR-21, miR-181b, miR-146a, miR-223, miR-155, miR-150) in plasma samples were quantified by quantitative polymerase chain reaction and their levels were correlated with the clinical characteristics in different subgroups. RESULTS: The relative expression of plasma miR-155 (P = .0003), miR-223 (P = .0316), and miR-21 (P = .0147) were significantly higher in patients who had subsequent histology-approved ABMR with donor-specific anti-HLA antibody positivity (n = 10) than in the "triple negative" group (n = 21), and miR-155 showed the highest sensitivity (90%) and specificity (81%) to indicate ABMR development based on receiver operating characteristic analysis. CONCLUSIONS: According to our preliminary data, plasma miR-155, miR-21, and miR-223 can indicate the development of ABMR after kidney transplant in correlation with classic clinical parameters. However, future studies with larger number of participants are necessary to further evaluate the diagnostic properties of blood miRNAs in prediction of this life-threatening condition.

Changes in serum pigment epithelium-derived factor levels after kidney transplantation in patients with end-stage renal disease.

BACKGROUND: Pigment epithelium-derived factor (PEDF) is a serin protease inhibitor and a potent inhibitor of angiogenesis. Its serum level has significant associations with metabolic parameters. However, little is known about the association between PEDF levels and lipid parameters in renal transplanted (TX) patients. Therefore, our aim was to investigate the relationship between PEDF level and lipid parameters in TX patients. METHODS: Seventy TX patients (47 males, 23 females, mean age 51.7 ± 12.4 years) and 34 healthy controls were enrolled. We examined the serum creatinine, C-reactive protein, fasting glucose and lipid parameters right before, then 1 and 6 months after TX. High-density lipoprotein (HDL)-associated paraoxonase-1 (PON1) activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. PEDF and oxidized low-density liporotein (oxLDL) levels were measured by ELISA. RESULTS: Before transplantation, patients had had a significantly higher PEDF level compared to control subjects (p < 0.001). One month after transplantation, their PEDF level decreased significantly reaching the healthy controls' level, and this lower level was maintained during the 6 months follow-up period as well. The initial oxLDL level was significantly higher, while PON1 activities were significantly lower in the patient group compared to the control group. We found a significant positive correlation between PEDF and total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, oxLDL and small HDL subfraction; while negative correlations were found between PEDF and mean LDL size and large HDL subfraction during the entire follow-up period. CONCLUSION: PEDF may play an important role in the increased oxidative stress and enhanced atherogenesis in renal transplant patients.

Impact of Diabetes Mellitus on Early Clinical Outcome and Stent Restenosis after Carotid Artery Stenting.

Background: Diabetes mellitus is closely related to both the severity of carotid disease and its outcome after revascularization. Carotid artery stenting (CAS) has emerged as a viable alternative to surgical endarterectomy but little is known about the impact of diabetes after CAS. Methods: A consecutive cohort of 1940 patients undergoing CAS in two institutions was divided into two groups, diabetics and nondiabetics, and major cerebrovascular events (MACCEs) were analyzed at 30 days post-CAS and at 1 year follow-up. Results: There were 730 patients with diabetes, with significantly higher BMI, hypertension, chronic dialysis, and dyslipidemia frequency (p < 0.05). There was no significant difference between the two groups in terms of early and late MACCEs (composite of transient ischemic attack, major stroke, myocardial infarction, and death), with an early rate of 3.5% nondiabetics vs. 5.3%, p = 0.08 and 2.4 nondiabetics vs. 2.3% diabetics, p = 0.1 at 12 months. Overall stroke/death rate in the asymptomatic patients was 2.4%, and the restenosis rate was higher in the diabetes population (2.3% vs. 1%, p = 0.04). Conclusion: The presence of diabetes was associated with an acceptable increased periprocedural risk for CAS, but no further additional risk emerged during longer term follow-up. Diabetes may precipitate the rate of early in-stent restenosis.

High Level of Unwarranted Clinical Variation in the Use of Lower Extremity Revascularisation Procedures in Hungary (2013-2017).

OBJECTIVE: Assessment of variations in the use of lower extremity open vascular surgical procedures (LEOPEN) and lower extremity endovascular procedures (LEENDO) across small geographic areas in Hungary from 2013 to 2017. Introduction of a new metric giving a rough estimate of unwarranted clinical variation in revascularisation practice. METHODS: Spatial variation (at local administrative unit level) of referral for LEOPEN and LEENDO was evaluated through a retrospective analysis using healthcare administrative data of all beneficiaries in Hungary. The same assessment was performed for percutaneous coronary intervention in acute myocardial infarction (PCIAMI). The latter was considered a reasonable comparator (similar at risk population, well organised, guideline driven patient pathways, small room for referral discretion). Consequently, the ratio of spatial variations of LEOPEN and LEENDO to PCIAMI (as a reference) are thought to reflect unwarranted clinical variation. RESULTS: A total of 109 882 procedures were identified in the database (LEOPEN, LEENDO, PCIAMI) affecting 85 083 patients. While estimates of spatial variations for LEOPEN and LEENDO turned out to be high (systematic component of variation [SCV] 0.09 and 0.21, respectively), PCIAMI showed a low SCV value of 0.02. Consequently, the ratios of SCVs were SCV/SCVref = 4.67 (LEOPEN) and SCV/SCVref = 10.3 (LEENDO), indicating high levels of unwarranted clinical variation. CONCLUSION: The analysis showed that patients living in different locations of Hungary face very different odds of having lower extremity revascularisation procedures (open or endovascular). This spatial variation is thought to be related mainly to the failure in vascular service organisation. The newly introduced numerical estimate of unwarranted clinical variation may support within, and also between, system comparisons.

Functional Voltage-Gated Sodium Channels Are Present in the Human B Cell Membrane.

B cells express various ion channels, but the presence of voltage-gated sodium (NaV) channels has not been confirmed in the plasma membrane yet. In this study, we have identified several NaV channels, which are expressed in the human B cell membrane, by electrophysiological and molecular biology methods. The sensitivity of the detected sodium current to tetrodotoxin was between the values published for TTX-sensitive and TTX-insensitive channels, which suggests the co-existence of multiple NaV1 subtypes in the B cell membrane. This was confirmed by RT-qPCR results, which showed high expression of TTX-sensitive channels along with the lower expression of TTX-insensitive NaV1 channels. The biophysical characteristics of the currents also supported the expression of multiple NaV channels. In addition, we investigated the potential functional role of NaV channels by membrane potential measurements. Removal of Na+ from the extracellular solution caused a reversible hyperpolarization, supporting the role of NaV channels in shaping and maintaining the resting membrane potential. As this study was mainly limited to electrophysiological properties, we cannot exclude the possible non-canonical functions of these channels. This work concludes that the presence of voltage-gated sodium channels in the plasma membrane of human B cells should be recognized and accounted for in the future.

TRIACCESS Study: Randomized Comparison Between Radial, Femoral, and Pedal Access for Percutaneous Femoro-popliteal Artery Angioplasty.

BACKGROUND: The aim of this randomized study was to compare the success and complication rates of different access sites for the treatment of superficial artery stenosis. METHODS AND RESULTS: A total of 180 consecutive patients were randomized in a prospective study to treat symptomatic superficial femoral artery stenosis via radial (RA), femoral (FA), or pedal artery (PA) access. Technical success was achieved in 96.7%, 100%, and 100% of the patients in the RA, FA, and PA groups, respectively (p=0.33). Secondary access sites were used in 30%, 3.3%, and 30% of the patients in the RA, FA, and PA access groups, respectively (p=0.0002). Recanalization for chronic total occlusion was performed in 34/36 (94.4%), 30/30 (100%), and 46/46 (100%) patients in the RA, FA, and PA groups, respectively (p=0.17). The X-ray dose was significantly lower in the PA group than that in the RA and FA access groups (63.1 vs 162 vs 153 Dyn, p=0.0004). The cumulative rates of access site complications in the RA, FA, and PA groups were 3.3% (0% major and 3.3% minor), 16.7% (3.3% major and 13.3% minor), and 3.3% (3.3% major and 0% minor) (p=0.0085), respectively. The cumulative incidence of MACEs at 6 months in the RA, FA, and PA groups was 5%, 6.7%, and 1.7%, respectively. The cumulative incidence of MALEs at 6 months in the RA, FA, and PA groups was 20%, 16.7%, and 9.2%, respectively (p=0.54). CONCLUSION: Femoral artery intervention can be safely and effectively performed using radial, femoral, and pedal access, but radial and pedal access is associated with a lower access site complication rate and hospitalization. Pedal access is associated with a lower X-ray dose than that with radial and femoral access.

Stent-Graft Treatment of a Giant Asymptomatic Extracranial Vertebral Artery Aneurysm: Case Report and Literature Review.

With the widespread appliance of endovascular techniques, a plethora of options is available in the treatment of extracranial vertebral artery aneurysms. If the vertebral artery can be sacrificed, embolization with coiling, liquid injection, or parent artery exclusion can be done. We hereby present a case of a 74-year-old male patient presenting with an asymptomatic atherosclerotic giant extracranial vertebral artery aneurysm in the V1 segment of the vertebral artery, successfully treated with balloon expandable stent-graft deployment. No neurologic symptoms occurred, and the stent-graft was patent with no signs of endoleak at 24 months follow-up with computed tomography angiography.

Digital variance angiography allows about 70% decrease of DSA-related radiation exposure in lower limb X-ray angiography.

Our aim was to investigate whether the previously observed higher contrast-to-noise ratio (CNR) and better image quality of Digital Variance Angiography (DVA) - compared to Digital Subtraction Angiography (DSA) - can be used to reduce radiation exposure in lower limb X-ray angiography. This prospective study enrolled 30 peripheral artery disease patients (mean ± SD age 70 ± 8 years) undergoing diagnostic angiography. In all patients, both normal (1.2 µGy/frame; 100%) and low-dose (0.36 µGy/frame; 30%) protocols were used for the acquisition of images in three anatomical regions (abdominal, femoral, crural). The CNR of DSA and DVA images were calculated, and the visual quality was evaluated by seven specialists using a 5-grade Likert scale. For investigating non-inferiority, the difference of low-dose DVA and normal dose DSA scores (DVA30-DSA100) was analyzed. DVA produced two- to three-fold CNR and significantly higher visual score than DSA. DVA30 proved to be superior to DSA100 in the crural region (difference 0.25 ± 0.07, p < 0.001), and there was no significant difference in the femoral (- 0.08 ± 0.06, p = 0.435) and abdominal (- 0.10 ± 0.09, p = 0.350) regions. Our data show that DVA allows about 70% reduction of DSA-related radiation exposure in lower limb X-ray angiography, providing a potential new radiation protection tool for the patients and the medical staff.