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Kidney & Blood Pressure Research Jun 2024The aim of the presented prospective observational study was to evaluate the effect of fistula flow on peripheral wave morphology and pulse wave velocity by means of the...
UNLABELLED
The aim of the presented prospective observational study was to evaluate the effect of fistula flow on peripheral wave morphology and pulse wave velocity by means of the oscillometric Vicorder®-device with the purpose of fistula surveillance.
METHODS
Digitized and normalized curves of 53 haemodialysis patients at the fistula and non-fistula arm were analyzed. Slope parameters and the areas under the curve of characteristic sections of pulse waves as well as the power spectrum of the pulse waves and their first and second derivatives were computed. Furthermore, the amplitude of volumetric change (AMP) was assessed. Duplex-sonography served as a reference method.
RESULTS
In the comprehensive set of novel pulse wave parameters significant inter-arm differences were demonstrated and a significant delay of the systolic maximum at the fistula arm in comparison to the non-fistula arm (204 ± 3.4 versus 162 ± 5.3 ms, p<0.001) was proven. Unexpectedly, pulse wave velocity apparently did not differ between both arms (7.85 versus 8.05 m/sec at the fistula/non-fistula side, p=0.942). The inter-arm differences of the slope parameters were more pronounced in forearm than in upper arm fistulas. Finally, we showed that the inter-arm difference of AMP correlated with volume-flow (r= 0.326 with p=0.017).
CONCLUSION
Pulse waves as assessed by oscillometric pulse wave analysis have distinct features at fistula and non-fistula arms. This is due to enhanced arteriovenous flow, i.e. in both the brachial artery and the fistula vein. The analysis of those alterations has the potential to assess fistula function.
PubMed: 38934146
DOI: 10.1159/000539885 -
Journal of Clinical Medicine Jun 2024: Arterio-venous fistulas (AVF) are used as first-line access for hemodialysis (HD) in the pediatric population. The aim of this investigation was to describe a...
: Arterio-venous fistulas (AVF) are used as first-line access for hemodialysis (HD) in the pediatric population. The aim of this investigation was to describe a single-center experience in the creation of AVF, together with its patency in children. : This single-center retrospective study included all patients aged ≤18 years with AVFs created between 1993 and 2023. The collected data included patients' demographics, hemodialysis history, intraoperative data, and required reinterventions in order to determine the impact of these variables on primary, primary-assisted, and secondary patency. : Fifty-seven patients were analyzed with a median age of 15 years (range, 7-18 years). Fifty-four forearm and four upper arm fistulas were performed. The median follow-up was 6.9 years (range, 0-23 years). The primary failure rate was 10.5%. The primary patency rate was 67.6%, 53.6%, 51.4%, and 38.1% after 1, 3, 5, and 10 years; primary-assisted patency was 72.9%, 62.8%, 60.6%, and 41.5%; and secondary patency was 87.3%, 81.3%, 76.8%, and 66.6% after 1, 3, 5, and 10 years in the studied population. : AVFs showed an acceptable rate of primary failure and excellent long-term patency. In this context, AVFs are an appropriate option for HD access, especially in pediatric patients.
PubMed: 38930106
DOI: 10.3390/jcm13123577 -
Journal of Clinical Medicine Jun 2024Congenital cervicofacial vascular anomalies are extremely rare and present many difficulties in diagnosis and treatment requiring a multidisciplinary approach. Firstly,... (Review)
Review
Congenital cervicofacial vascular anomalies are extremely rare and present many difficulties in diagnosis and treatment requiring a multidisciplinary approach. Firstly, there is little consensus on this subject among head and neck specialists. There are two main types of vascular anomalies: vascular tumors and vascular malformations. Vascular malformations are also divided into malformations with slow blood flow (veins, lymphatics, capillaries or combined) and malformations with a fast blood flow (arteriovenous malformations and fistula). Vascular tumors like hemangiomas are known for their spontaneous involution with aging, while vascular malformations grow in dimensions with age. It is very important to choose the correct differential diagnosis between cervicofacial hemangiomas and vascular malformations for proper therapy management. Anamnesis and clinical exams help in raising suspicions about the real nature of a cervico-vascular anomaly. Furthermore, imaging brings in-depth details of the anomaly, ranging from ultrasound and contrast CT to MRI scanning and minimally invasive angiography. Angiography with selective embolization is rarely a curative procedure for arteriovenous malformations, being more suitable as a preliminary step before attempted surgical removal. Surgery is clearly necessary when there are aesthetic and functional deficits. Slow-flow vascular malformations present a reduced morbidity, and in cases without involution, the surgical ablation is reserved for the cases with aesthetic dysfunctions or psychological trauma. Lymphatic malformations must undergo surgical ablation when they are associated with mass effects and compression of great vessels or aerial viscera. The prognosis after surgical removal is good, with a low rate of recurrence or morbidity. Fast-flow vascular malformations require a combined approach, with embolization and excision in the next 48 h for safety reasons. Removal may be followed by reconstructive surgery depending on the location and dimensions of the malformation, with a possible secondary recovery of the normal microscopic vessels. Some of the masses may hinder the normal airflow and swallowing. Pathology is the gold standard for confirming the clinical and imaging diagnosis.
PubMed: 38930043
DOI: 10.3390/jcm13123515 -
Journal of Personalized Medicine Jun 2024Intermittent hemodialysis (HD) in high-bleeding-risk patients presents a challenge as circuit anticoagulation using heparin is contraindicated in such cases. Recently,...
Intermittent hemodialysis (HD) in high-bleeding-risk patients presents a challenge as circuit anticoagulation using heparin is contraindicated in such cases. Recently, the use of calcium-free citrate-containing dialysate with calcium supplementation emerged as a viable alternative to heparin-circuit anticoagulation. This is a retrospective, monocentric study to evaluate dialysis efficacy using calcium-free citrate-containing dialysate with calcium reinjection into the venous line in hemodialysis patients at risk of bleeding. A total of 53 patients were analyzed: 52 had a temporary contraindication to systemic anticoagulation (active bleeding or surgical intervention), and 1 chronic HD patient had prolonged bleeding time due to inoperable arteriovenous fistula stenosis. Only 7 out of 79 dialysis sessions performed were prematurely terminated (vascular access dysfunction). The median dialysis time was 240 min (range: 150-300). The chronic dialysis patient had 108 sessions with no premature termination. Frequent monitoring of ionized calcium was performed throughout the dialysis sessions: levels remained stable at T0 and T + 60 min (1.08 ± 0.08 mmol/L) and slightly increased at the end of the dialysis session (1.19 ± 0.13 mmol/L), remaining within normal limits. Target postfilter ionized calcium <0.4 mmol/L was achieved in all sessions (0.31 ± 0.07 mmol/L). There were no cases of symptomatic hypo-/hypercalcemia and no need for calcium infusion rate adjustment throughout the sessions. Hemodialysis with calcium-free citrate-containing dialysate and calcium reinjection into the venous line is efficient and safe in HD patients with contraindications to systemic anticoagulation.
PubMed: 38929882
DOI: 10.3390/jpm14060660 -
Diagnostics (Basel, Switzerland) Jun 2024: The ability of hemoglobin to bind and dissociate oxygen is crucial in delivering oxygen to tissues and is influenced by a range of physiological states, compensatory...
: The ability of hemoglobin to bind and dissociate oxygen is crucial in delivering oxygen to tissues and is influenced by a range of physiological states, compensatory mechanisms, and pathological conditions. This may be illustrated by the oxyhemoglobin dissociation curve (ODC). The key parameter for evaluating the oxygen affinity to hemoglobin is p50. The aim of this study was to evaluate the impact of hemodialysis on p50 in a group of patients with chronic kidney disease (CKD). An additional goal was to assess the correlation between p50 and the parameters of erythropoiesis, point-of-care testing (POCT), and other laboratory parameters. : One hundred and eighty patients (106 male, 74 female), mean age 62.5 ± 17 years, with CKD stage G4 and G5 were enrolled in this cross-sectional study. Patients were divided into two groups, including 65 hemodialysis (HD) patients and 115 patients not receiving dialysis (non-HD). During the standard procedure of arteriovenous fistula creation, blood samples from the artery (A) and the vein (V) were taken for POCT. The causes of CKD, as well as demographic and comorbidity data, were obtained from medical records and direct interviews. : The weekly dose of erythropoietin was higher in HD patients than in non-HD patients (4914 ± 2253 UI vs. 403 ± 798 UI, < 0.01), but hemoglobin levels did not differ between these groups. In the group of non-HD patients, more advanced metabolic acidosis (MA) was found, compared to the group with HD. In arterial and venosus blood samples, the non-HD group had significantly lower pH, pCO and HCO. This group had a higher proportion of individuals with MA with HCO < 22 mmol/L (42% vs. 24%, < 0.01). The absolute difference of p50 in arterial and venous blood was determined using the formula Δp50 = (p50-A) - (p50-V). Δp50 was significantly higher in the HD group in comparison to non-HD (0.08 ± 2.05 mmHg vs. -0.66 ± 1.93 mmHg, = 0,02). There was a negative correlation between pH and the p50 value in arterial (pH-A vs. p50-A, r = -0.56, < 0.01) and venous blood (pH-V vs. p50-V, r = -0.45, < 0.01). In non-HD patients, hemoglobin levels correlated negatively with p50 (r = -0.29, < 0.01), whereas no significant relation was found in HD patients. : The ODC in pre-dialysis CKD (non-HD) patients is shifted to the right due to MA, and this is an additional factor influencing erythropoiesis. Hemodialysis restores the natural differences in hemoglobin's dissociation characteristics in the arterial and venous circulation.
PubMed: 38928635
DOI: 10.3390/diagnostics14121219 -
Revista Latino-americana de Enfermagem 2024to evaluate the effect of an educational video on the knowledge, attitude, and practice of self-care with arteriovenous fistula in patients undergoing hemodialysis... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
to evaluate the effect of an educational video on the knowledge, attitude, and practice of self-care with arteriovenous fistula in patients undergoing hemodialysis treatment.
METHOD
randomized controlled clinical trial, with two arms and single-blind. The intervention used an educational video on arteriovenous fistula self-care. The Fistula Self-Care Knowledge, Attitude, and Practice Scale was applied to 27 renal patients on hemodialysis in the control group and 28 in the intervention group at baseline, after seven and fourteen days. The data was analyzed using the Statistical Package for the Social Sciences software, using the chi-square test, Student's t-test, Mann-Whitney test, and Friedman's test with post-hoc analysis for multiple comparisons.
RESULTS
there were statistically significant differences in the knowledge and practice of self-care with the fistula at 0, 7 and, 14 days in the intervention (p= 0.004 and p<0.001, respectively) and control groups (p<0.001 for knowledge and practice). Attitude showed a significant difference at follow-up (p<0.001), but the post-hoc analysis did not confirm the significance obtained.
CONCLUSION
patients' knowledge and practice showed significant increases at follow-up in the control and intervention groups, while the increase in attitude was not significant in either group. Clinical trial, registration number: U1111-1241-6730.
Topics: Humans; Self Care; Female; Male; Patient Education as Topic; Single-Blind Method; Middle Aged; Renal Dialysis; Arteriovenous Shunt, Surgical; Video Recording; Health Knowledge, Attitudes, Practice; Adult; Aged
PubMed: 38922264
DOI: 10.1590/1518-8345.6949.4185 -
Annals of Vascular Diseases Jun 2024Ruptured abdominal aortic aneurysms and common iliac artery aneurysms (CIAAs) are rarely associated with an arteriovenous fistula (AVF). In such cases, surgery is...
Ruptured abdominal aortic aneurysms and common iliac artery aneurysms (CIAAs) are rarely associated with an arteriovenous fistula (AVF). In such cases, surgery is frequently extremely difficult and the prognosis is usually poor. We report a case of a ruptured CIAA with a common iliac AVF in a 58-year-old male patient who presented with symptoms of severe edema in his left lower extremity. We used an aneurysm wall patch to repair the fistula and successfully reconstruct the common iliac vein, and a bifurcated prosthetic graft for abdominal aortic and iliac artery replacement.
PubMed: 38919327
DOI: 10.3400/avd.cr.23-00122 -
Journal of Neuroendovascular Therapy 2024Neurofibromatosis type 1 (NF1) is associated with vascular fragility, which results in aneurysms, arteriovenous fistulas, and dissections. Here, we describe a case of...
OBJECTIVE
Neurofibromatosis type 1 (NF1) is associated with vascular fragility, which results in aneurysms, arteriovenous fistulas, and dissections. Here, we describe a case of endovascular treatment of a ruptured occipital artery aneurysm that occurred after a craniotomy in a patient with NF1.
CASE PRESENTATION
A 46-year-old man with a history of NF1 underwent a right lateral suboccipital craniotomy to remove a cavernous hemangioma in the right middle cerebellar peduncle. Severe bleeding occurred in the occipital artery during the craniotomy. Due to vessel fragility, coagulation and ligation were not possible, and pressure hemostasis was achieved using cellulose oxide and fibrin glue. On postoperative day 12, the patient developed a sudden swelling on the right side of the neck as well as tracheal compression. Contrast-enhanced CT revealed a ruptured aneurysm in the right occipital artery. Transarterial embolization was performed under general anesthesia the same day. Right external carotid angiography showed an 18-mm-diameter fusiform aneurysm in the occipital artery. The aneurysm ruptured inferiorly to form a large pseudoaneurysm with significant jet flow. An arteriovenous fistula was also observed in a nearby vein. A microcatheter was inserted into the fusiform aneurysm under proximal blood flow control, and embolization was performed using coils and -butyl-2-cyanoacrylate.
CONCLUSION
Compared to surgical repair of ruptured occipital artery aneurysms, endovascular treatment appears to be safe, effective, minimally invasive, and rapid. Ruptured occipital artery aneurysms in NF1 patients can cause neck swelling and airway compression and should be recognized as a potentially lethal condition.
PubMed: 38911485
DOI: 10.5797/jnet.cr.2023-0098 -
Journal of Zhejiang University.... Jun 2024Artificial vascular graft (AVG) fistula is widely used for hemodialysis treatment in patients with renal failure. However, it has poor elasticity and compliance, leading...
Artificial vascular graft (AVG) fistula is widely used for hemodialysis treatment in patients with renal failure. However, it has poor elasticity and compliance, leading to stenosis and thrombosis. The ideal artificial blood vessel for dialysis should replicate the structure and components of a real artery, which is primarily maintained by collagen in the extracellular matrix (ECM) of arterial cells. Studies have revealed that in hepatitis B virus (HBV)-induced liver fibrosis, hepatic stellate cells (HSCs) become hyperactive and produce excessive ECM fibers. Furthermore, mechanical stimulation can encourage ECM secretion and remodeling of a fiber structure. Based on the above factors, we transfected HSCs with the hepatitis B viral X () gene for simulating the process of HBV infection. Subsequently, these -HSCs were implanted into a polycaprolactone-polyurethane (PCL-PU) bilayer scaffold in which the inner layer is dense and the outer layer consists of pores, which was mechanically stimulated to promote the secretion of collagen nanofiber from the -HSCs and to facilitate crosslinking with the scaffold. We obtained an ECM-PCL-PU composite bionic blood vessel that could act as access for dialysis after decellularization. Then, the vessel scaffold was implanted into a rabbit's neck arteriovenous fistula model. It exhibited strong tensile strength and smooth blood flow and formed autologous blood vessels in the rabbit's body. Our study demonstrates the use of human cells to create biomimetic dialysis blood vessels, providing a novel approach for creating clinical vascular access for dialysis.
Topics: Rabbits; Animals; Hepatic Stellate Cells; Renal Dialysis; Polyesters; Viral Regulatory and Accessory Proteins; Tissue Scaffolds; Transfection; Bionics; Polyurethanes; Blood Vessel Prosthesis; Extracellular Matrix; Humans; Hepatitis B virus; Collagen; Tissue Engineering; Trans-Activators
PubMed: 38910495
DOI: 10.1631/jzus.B2300479 -
Journal of Biomechanics Jun 2024Arteriovenous fistula (AVF) is the optimal form of vascular access for most haemodialysis dependant patients; however, it is prone to the formation of stenoses that...
Arteriovenous fistula (AVF) is the optimal form of vascular access for most haemodialysis dependant patients; however, it is prone to the formation of stenoses that compromise utility and longevity. Whilst there are many factors influencing the development of these stenoses, pathological flow-related phenomena may also incite the formation of intimal hyperplasia, and hence a stenosis. Repeated CFD-derived resistance was calculated for six patient who had a radiocephalic AVF, treated with an interwoven nitinol stent around the juxta-anastomotic region to address access dysfunction. A three-dimensional freehand ultrasound system was used to obtain patient-specific flow profiles and geometries, before performing CFD simulations to replicate the flow phenomena in the AVF, which enabled the calculation of CFD-derived resistance. We presented six patient cases who were examined before and after treatment and our results showed a 77% decrease in resistance, recorded after a surgical intervention to address access dysfunction. Problematic AVFs were found to have high resistance, particularly in the venous segment. AVFs with no reported clinical problems, and clinical patency, had low resistance in the venous segment. There did not appear to be any relationship with clinical problems/patency and resistance values in the arterial segment. Identifying changes in resistance along the circuit allowed stenoses to be identified, independent to that determined using standard sonographic criteria. Our exploratory study reveals thatCFD-derived resistance is a promising metric that allows for non-invasive identification of diseased AVFs. The pipeline analysis enabled regular surveillance of AVF to be studied to aid with surgical planning and outcome, further exhibiting its clinical utility.
PubMed: 38908106
DOI: 10.1016/j.jbiomech.2024.112203