Arteriovenous Fistula Formation Research Articles

Outcomes of Surgical and Endovascular Treatment for Cephalic Arch Stenosis in Proximal Arteriovenous Fistula.

The cephalic arch is a significant site of stenosis in proximal arteriovenous fistulas (AVFs) that contributes to access dysfunction and thrombosis. This study aimed to evaluate the outcomes of surgical treatment (ST) and endovascular treatment (ET) for cephalic arch stenosis (CAS). A total of 62 patients with proximal AVF who underwent CAS revision using either ST or ET were enrolled between January 2018 and March 2023. In the ET group, only the initial ET following AVF formation was considered, to mitigate bias. In the ST group, central transposition of the native AVF (transposition group) or interposition of the prosthetic graft into the proximal basilic or axillary vein (interposition group) was performed. We evaluated primary and functional patency based on these groups and calculated the number of patency loss events after CAS treatment. Of the 62 patients, 38 (61%) were male, with a mean age of 66.4 years. ST was performed in 26 (42%) patients, including transposition in 16 and interposition in 10, whereas ET was administered to 36 patients during the study period. Among the ST recipients, 42% had a history of ET for CAS. The incidence of AVF thrombosis was marginally higher in the ST group than in the ET group (39% vs. 19%, P=0.098). The primary patency rates at 6 months, 1 year, and 3 years were 87%, 87%, and 66% in the transposition group; 45%, 23%, and 11% in the interposition group; and 66%, 49%, and 17% in the ET group, respectively. Notably, the primary patency of the transposition group was significantly higher than that of the interposition (P=0.001) and ET groups (P=0.016). The frequency of patency loss events per person-year after the initial revision was 0.40, 0.52, and 1.42 in the transposition, interposition, and ET groups, respectively. Transposition exhibited the most favorable primary patency rate and the lowest number of subsequent patency loss events during follow-up despite the higher rates of AVF thrombosis and previous ET at presentation. Consequently, transposition should be actively considered in eligible patients with CAS.

Evaluation of the Safety and Efficacy of Coronary Intervention through the Brachial Artery Compared to the Radial Artery in Elderly Patients with Different Extubation Times

Introduction: Percutaneous coronary intervention (PCI) is an important treatment for acute coronary syndrome. The main puncture paths of PCI include radial artery, brachial artery, and femoral artery. The aim of this study was to investigate the safety and efficacy of transbrachial intervention in elderly patients. Methods: According to intraoperative and postoperative nursing records, a retrospective analysis was performed for 70 elderly patients who underwent coronary intervention were divided into brachial artery A group (33 cases) and brachial artery B group (37 cases) according to immediate postoperative extubation compression dressing and 6 hours postoperative extubation compression dressing, and matched elderly patients who had successful transradial artery puncture in the same period as radial artery group (35 cases). The success rate of puncture and catheterization, arterial puncture time, total operation time, length of hospital stay, patient comfort score, incidence of arterial spasm and occlusion, subcutaneous ecchymosis and hematoma, epidermal blister occurrence, vagal reflex, pseudoaneurysm development, arteriovenous fistula formation, nerve damage risk assessment and osteofascial compartment syndrome were compared. Results: Compared with the radial artery group, the brachial artery group (group A and group B) had a higher success rate of puncture and catheterization (97.0% vs. 97.3% vs. 80.0%, p = 0.013), shorter arterial puncture time (2.45 ± 0.38 vs. 2.40 ± 0.35 vs. 3.40 ± 0.37, p = 0.000), and lower incidence of arterial spasm (0.0% vs. 0.0% vs. 34.3%, p = 0.000), arterial occlusion (0.0% vs. 0.0% vs. 14.3%, p = 0.005) and puncture site bleeding (12.1% vs. 5.6% vs. 40.0%, p = 0.001). The incidence of epidermal blister was higher in brachial artery A group than in brachial artery B group (24.2% vs. 2.7%, p = 0.003) or radial artery group (24.2% vs. 0%, p = 0.001), and the incidence of epidermal blister in brachial artery B group and radial artery group was not much different. There was no difference between the three groups in total operation time, length of hospital stay, comfort score, subcutaneous ecchymosis and hematoma, vagal reflex, pseudoaneurysm, arteriovenous fistula, nerve damage and osteofascial compartment syndrome. Conclusion: In elderly patients, coronary intervention through brachial artery is not inferior to radial artery.

Accuracy of physical examination versus Doppler ultrasonography for determining maturity in postoperative arteriovenous fistula formation

Differentiating between arteriovenous fistula (AVF) maturation and failure can help determine which AVF will undergo successful canulation and which ones will require immediate rescue. A prospective observational study was conducted at Vajira Hospital in Bangkok, Thailand, between October 2020-November 2022. A single vascular surgeon performed a physical examination on patients with chronic kidney disease undergoing AVF placement, and a radiologist conducted Doppler ultrasonography during the second and sixth postoperative weeks. Dialysis nurses determined AVF maturity by performing cannulation. The study compared the accuracy of physical examination and Doppler ultrasonography. A model was developed to predict the success of AVF use. Out Of the 125 recruited patients, 81% demonstrate unassisted maturation of their AVF. The male sex and brachiocephalic type are associated with AVF maturation. The physical examination findings of palpable thrill and the absence of a strong pulse at the 6th week show an area under the receiver operating curve (AUC) value of 0.79. Similarly, arterial end-diastolic velocity on ultrasonography at the 6th week also demonstrates a comparable predictive value with an AUC of 0.82 (p=0.697). Meanwhile, the model that combined end-diastolic velocity and venous volume flow yields the best results for predicting AVF maturation, with an AUC of 0.92. These models provide more accurate predictions compared to physical examination alone (AUC: 0.92 vs. 0.79; p<0.01). Although a prudent physician predicts AVF maturation through a thorough physical examination, Doppler ultrasonography is preferred in anticipating the success of postoperative AVF placement.

Results of Primary Arteriovenous Fistulas Formation with Different Types of Anastomoses in the Early Postoperative Period in Patients on Programmed Hemodialysis

The study includes the analysis of the results of using the different types of arteriovenous anastomoses in the formation of arteriovenous fistulas and their impact on fistula maturation in the early postoperative period. One of the main aspects of the work is to determine the optimal type of anastomosis to ensure the proper functioning of arteriovenous fistula that is an important element of vascular access in patients on renal replacement therapy. It is important to consider such factors as the diameter of formed arteriovenous fistula, the blood flow velocity through it, the incidence of complications and the duration of its functioning. The study also takes into account the impact of patients’ characteristics, such as age, condition of arteries and veins, as well as general health indicators on the results of surgery. Taking these factors into account allows to identify the groups of patients who can benefit most from a particular type of anastomosis.&#x0D; During the sample period, 384 patients with terminal stage of renal failure aged 20 to 84 years undergoing programmed hemodialysis, the native arteriovenous fistula was formed. It was found that 94.01 % of arteriovenous fistulas were successful in the early postoperative period. The average age of these patients was 44.2 years, while unsuccessful cases developed in people with an average age of 66.8 years. It was also found that within an hour after surgery for the formation of an arteriovenous fistula with the type end-to-side anastomosis, its diameter increases from 2.08±0.42 mm to 2.96±1.68 mm, and the blood flow velocity increases from 21.4±7.6 ml/min to 212.4±74.6 ml/min. The risk factor for effective fistula formation, in addition to age, is the diameter of vessels, anatomical features of the venous system, the presence of concomitant pathology (primarily diabetes mellitus).&#x0D; The obtained results can serve as a basis for the developing of recommendations for the optimal choice of anastomosis type for certain categories of patients who will undergo renal replacement therapy. The study is aimed at improving the results of surgical treatment and increasing the quality of life of patients with chronic renal failure.

De novo formation of remote dural arteriovenous fistula following treated cavernous sinus dural arteriovenous fistula

BackgroundThe development of new dural arteriovenous fistulas (DAVFs) at another location following endovascular treatment of cavernous sinus DAVFs (CSDAVFs) are extremely rare. Our aim is to review cases of de Novo DAVFs that occurred after treatment of CSDAVFs at our institution and those reported in the literature. MethodsWe reviewed all cases of CSDAVFs evaluated by 2 experienced neuroradiologists. A literature search was performed using the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines focusing on De Novo DAVFs following the endovascular treatment of cerebrovascular malformations. Addition articles were searched through the reference lists of the included articles. ResultsFrom June 2004 and September 2019., we identified 3 (2.5%) cases of De Novo DAVFs occurred after endovascular treatment or spontaneous obliteration of CSDAVFs from 119 treated CSDAVFs at our institute. Our review yielded 9 articles involving 12 patients with 15 de novo DAVFs, including our 3 patients. The mean age was 55.08 ± 12.9 years (range 43–69), 83.3% were females (n = 10). The new remote DAVFs occurred after endovascular treatment of CSDAVFs in 10 (83.3%) patients. The de novo DAVFs occurred following spontaneous complete regression in 2 (16.7%) patients. All de novo DAVFs developed after complete obliteration of treated CSDAVFs. ConclusionSinus thrombosis and elevated venous pressure may play an important role in the pathogenesis of a de novo DAVF formation. In addition, thrombophilic abnormalities and the use of contraceptives may contribute to sinus thrombosis, leading to the development of the second remote DAVF after treatment of CSDAVFs.

AUDIT OF COVID-19 WARD PERFORMANCE AND PRACTICE IN THE COVID-19 PANDEMIC: FUTURE DIRECTIONS FOR UNDERSTANDING: A RETROSPECTIVE STUDY

A retrospective study was conducted to assess the trend of the COVID-19 pandemic in the COVID Ward emergency and COVID Ward treatment departments of the Department of COVID Ward at POF Hospital Wah Cantt from January 2021 to January 2022. Data on every patient admitted to the COVID Ward department over a year was gathered retroactively. The following demographic factors were recorded: diagnosis, COVID-19 work-up, admission specialization, and COVID-19 ward vs. conservative therapy. In total, there were 156 patients, with 108 being primarily men (70.4%). Of these patients, 90 (72%) were admitted via the clinic, and 124 (46%) were admitted in May. One hundred five patients (62.8%) had a COVID-19 PCR, 135 had a chest x-ray (90.2%), and 56 patients (31.4%) had a chest HRCT.  The orthopedic COVID Ward was the most common department for operational interventions, with 88.4% of patients undergoing operative care, despite the general COVID Ward being the busiest service line with 89 total patient admissions (43.1%).  The study found that the existing local protocols for patient flow and COVID-19 crisis management are effective and practical. Hospitals should be prepared to redirect their resources to high-volume specialties like orthopaedics and general COVID Wards after the later COVID-19 waves. Arteriovenous fistula formation is a simple yet crucial technique that should only be discontinued in the event of a labor shortage.

Single-access, non-contrast transcatheter aortic valve implantation, the ultimate minimalist approach: a case report

Abstract Background Transcatheter aortic valve implantation (TAVI) is an established treatment for patients with symptomatic severe aortic stenosis. Patients with previous renal transplant are considered as a high-risk cohort who may develop procedural complications related to vascular access and renal impairment post-TAVI. Case summary Herein, we report a case of an 88-year-old male who presented with progressive dyspnoea. His transthoracic echocardiogram revealed severe aortic stenosis with a peak gradient of 75 mmHg and impaired left ventricle systolic function (an estimated ejection fraction of 40%). He had a background of kidney transplant with progressive decline in renal function, requiring the formation of left arm arteriovenous fistula in preparation for future dialysis. He was successfully treated with TAVI using a single vascular access site without administering contrast media. Discussion Single-access, non-contrast TAVI is feasible when treating renal transplant patients with severe aortic stenosis and limited vascular access. The current minimalistic approach should be used only in highly selective patient cases.

Effect of Different Methods of Anesthesia on Surgically Created Arteriovenous Fistula

Aim of the study was to determine the advantages of peripheral nerve blocks (PNB) versus local infiltration anesthesia (LIA) in the formation of arteriovenous fistula (AVF) surgically created for hemodialysis treatmentType of study: prospective non-randomized study. Approved by the ethics committee of JLF UK in Martin.Type of workplace: clinical workplace of a university hospital.Material and method. The cohort of patients (N=40) who required arteriovenous fistula (AVF) creation was divided into 2 groups, 20 patients each: patients operated under peripheral nerve blockade and patients operated under local infiltration anesthesia. The preserved function of the fistula was monitored 24 hours, 6 weeks and one year after the operation, without revision. Patient inclusion criteria included: age 19–75 years, ASA 3–4, weight 40–120 kg, BMI up to 40. Statistical treatment of data included Mann-Whitney exact test, Fisher's test, t-test, Shapiro–Wilk normality test.Results. After 24 hours, all fistulas created with peripheral nerve blockade were functional whereas only 90% developed under local infiltration anesthesia remained functional (P&gt;0.05 between groups). However, after 6 weeks, 80% of fistulas created under peripheral nerve block were functional, compared to 50% of functional fistulas created in patients under local infiltration anesthesia (P=0.048). One year after surgery, the difference remained as a trend since 55% of fistulas created under peripheral nerve block remained functional while only 35% of fistulas created in patients receiving local infiltration anesthesia were functional without complications (P=0.097).Conclusion. In our study, the peripheral nerve block anestesia seem superior in term of improved survival of created fistula compared to local infiltration anesthesia.

A rare case report: compartment syndrome after brachiocephalic arteriovenous fistula formation in a hemodialysis patient

Introduction: Acute compartment syndrome is a condition in which increased pressure in the tight fascia space reduces capillary perfusion below the level required for tissue viability. Very few cases of acute compartment syndrome associated with dialysis have been reported. It can lead to severe damage to the tissues of the arm. Case Illustration: A 47-year-old woman with end-stage renal failure presented to the emergency room with swelling and pain in the right upper extremity and has lasted for a day. Three days before admission, the patient underwent right brachiocephalic arteriovenous (AV) fistula surgery. Physical Examination showed a blackish bruise at the fossa cubiti, radial and ulnar artery were not palpable, but there is trill at AV fistula. Decreased motoric strength, reduced hand sensation and decreased capillary return in fingers. Oxygen blood saturation of the right fingers could not be read. Diagnosis of acute compartment syndrome was made. The patient was immediately taken to the operating room for decompression surgery. Emergency compartment fasciotomy was performed. After fasciotomy, necrotomy was performed. Furthermore, brachiocephalic AV fistula was ligated. Postoperative evaluation obtained good radial and ulnar artery. Six months after the surgery, the wound was fully healed and no sign of neuromuscular or vascular deficit. Conclusion: Compartment syndrome is a possible complication after AV fistula formation that can have disastrous consequences. However, it can be effectively treated if detected and treated early. Prognosis of compartment syndrome after fasciotomy depends on how quickly the condition is diagnosed and treated.

Successful Endovascular Treatment of Postbiopsy AVF in Transplanted Kidneys: Lessons Learned from Two Cases in Multiorgan Transplant Recipients

AbstractAllograft biopsy is a cornerstone in the management of transplanted kidneys. It is a safe procedure, often performed in the outpatient setting. A rare complication is formation of a postbiopsy arteriovenous fistula (AVF). We present here a report of two cases of postbiopsy AVFs treated endovascularly. Selective embolization is a safe and effective method of treatment of postbiopsy AVFs in renal allografts.

Management of Traumatic Arteriovenous Fistula as a Complication of Minimally Invasive Endoscopic Maxillofacial Surgery: A Case Report

A traumatic arteriovenous fistula (AVF) is a type of acquired vascular malformation, caused by blunt or penetrating trauma. Traumatic AVFs result in a pathologic connection between arterial and venous vasculature, bypassing the corresponding capillaries. When an intra-operative insult to vasculature within a surgical site is implicated in the subsequent formation of a traumatic AVF, the suspected etiology is iatrogenic. Although the most common etiology of traumatic AVFs of the entire body is iatrogenic trauma, intraoperative vascular insults (ie, ligation and cauterization) are routinely delivered within maxillofacial surgical sites, without formation of an acquired vascular malformation. A traumatic AVF in the pre-auricular region is exceedingly rare and has infrequently been described as a complication following minimally invasive temporomandibular joint (TMJ) surgery, managed with endovascular surgery. We describe a rare case of bilateral TMJ arthroscopies complicated by the formation of a pulsatile, traumatic AVF between the right superficial temporal artery and right retromandibular vein, treated with minimally invasive endovascular embolization by the interventional radiology team. This case report highlights the diagnosis of a traumatic AVF in the pre-auricular region and multi-specialty management of an early complication of minimally invasive maxillofacial surgery.

Same day discharge after large bore vascular access in percutaneous coronary intervention of chronic total coronary occlusions

Abstract Background Same day discharge (SDD) in patients undergoing percutaneous coronary intervention (PCI) of a chronic total coronary occlusion (CTO) appears feasible, safe, and carries economic advantage. However, SDD may be hampered by the application of large bore dual arterial access, due to its association with vascular complications. Nevertheless, increasing French size augments therapeutic options and is therefore considered fundamental in complex CTO PCI. Purpose The present study investigated the feasibility of SDD in patients undergoing CTO PCI with large bore dual arterial access. Methods Between 2013 and 2018, a total of 683 patients were prospectively enrolled in a single-center CTO registry and underwent single-vessel CTO PCI. Large bore arterial access was defined as the application of 7 and/or 8 French sheaths in at least one access site. Technical success was defined as Thrombolysis in Myocardial Infarction flow grade 3 and residual stenosis &amp;lt;30%. Vascular access complications were defined as a composite of clinically significant bleeding and/or hematoma, urgent transfusion, dissection, pseudoaneurysm, arteriovenous fistula formation, and thrombosis. Results Mean age was 66 ± 11 years; 83% were male. Large bore arterial access was applied in 87%; the most common set-up was radial-femoral (68%) and bifemoral (23%) access. In 432 (62%) patients, SDD was achieved. Patients within the SDD group were younger and had lower rates of prior MI, prior CABG, renal insufficiency, and peripheral artery disease. A high Japanese CTO score (≥2) was less common in patients with versus without SDD (58% vs. 72%, p&amp;lt;0.001). In addition, technical success rate was higher in the SDD group (96% vs. 89%, p&amp;lt;0.001). Vascular access complications were found in 22 (3,2%) cases, with 17 (77,2%) occurring in the non-SDD group. Local access site bleeding was found to be the most common complication (82,4% of total vascular access complications). Finally, multivariable analysis showed that female gender (OR 2.22, 95% CI: 1.30 – 3.78) and local access site bleeding (OR 12.0, 95% CI: 4.37 – 33.21) were significantly associated with a lower probability of SDD. Conclusions Our study demonstrates the feasibility of SDD in the majority of patients undergoing CTO PCI with large bore dual arterial access, with high rates of technical CTO PCI success and acceptable vascular access complication rates. Care should be taken to avoid local access site bleeding since this hinders SDD.

Lumbo-renal arteriovenous fistula: An unusual complication of percutaneous kidney biopsy

Arteriovenous fistula formation after percutaneous kidney biopsy is not uncommon. Most of these fistulas are intrarenal and close spontaneously. Formation of a fistula between an intercostal branch of the lumbar artery and the renal vein is a very rare complication. Our case has lumbo-renal arteriovenous fistula (AVF) following a percutaneous kidney biopsy. The AVF was successfully treated with embolization. Post-biopsy observations should include Doppler surveillance in order to detect such rare but potentially catastrophic complications.

Renal Arteriovenous (AV) Fistula after High-Grade Blunt Renal Trauma Caused by Traffic Accidents.

To report a series of three patients with traumatic renal AV fistulas after blunt renal laceration. We retrospectively analyzed the renal trauma cases treated in the Department of Urology of Salzburg University Clinic during a time period of 10 years concerning traumatic AV fistula formation and other clinical parameters. In total, 3 cases of traumatic AV fistula formation were identified in 106 blunt renal trauma patients (2.8%), with a mean age of 39 (17-56) years. All renal traumas were classified as American Association for the Surgery of Trauma (AAST) grade IV. Two patients were primarily treated with ureteral stent; one was managed conservatively. All AV fistulas were diagnosed after a mean time of 7 (1-13) days. Two patients were symptomatic with gross hematuria, and the mean time between trauma and onset of symptoms was 11 (9-13) days. All cases were managed via coil embolization after a mean of 10 (8-13) days. Two patients received a second intervention after a mean of 18 (11-25) days. The mean AV fistula size was 18.7 (12-24) mm. Mean hemoglobin loss was 3.6 g/dL. One patient received one erythrocyte concentrate. Discharge was after a mean time of 13.3 (7-12) days, with the mean time of intensive care treatment being 2.3 (1-3) days. Traumatic renal AV fistula is a rare but severe complication associated with higher-grade renal trauma. It can become evident through hematuria or blood loss several days after the initial trauma. The availability of coil embolization in a trauma center can help kidney preservation management.

Osteopontin is a key regulator of vascular smooth muscle cell proliferation in the outflow vein of arteriovenous fistulas.

Despite advances in the maintenance of arteriovenous fistulas (AVFs), the patency rates remain suboptimal. Most AVFs fail due to outflow vein stenosis; however, the underlying mechanism of AVF stenosis remains unclear. The present study aimed to identify key factors associated with AVF outflow stenosis. We obtained gene expression profiling data for the outflow vein of AVF from three Gene Expression Omnibus database datasets (GSE39488, GSE97377, and GSE116268) and analyzed the common differentially expressed genes (DEGs). We evaluated a common DEG in an aortocaval mouse model and the stenotic outflow veins of AVFs collected from patients. Furthermore, we isolated vascular smooth muscle cells (VSMCs) from the inferior vena cava (IVC) of wild-type (WT) and osteopontin (Opn)-knockout (KO) mice and assessed the proliferation of VSMCs following stimulation with platelet-derived growth factors (PDGFs). OPN was the only common upregulated DEG among all datasets. OPN was expressed in the medial layer of the outflow vein of AVF in aortocaval mouse models and co-stained with the VSMC marker (α-smooth muscle actin). OPN expression was markedly increased in the VSMCs of stenotic outflow veins of AVF collected from patients undergoing hemodialysis compared to presurgical veins acquired during AVF formation surgery. PDGF-induced VSMC proliferation was significantly increased in the VSMCs isolated from the IVC of WT mice but not in those isolated from the IVC of Opn-KO mice. OPN may be a key gene involved in VSMC proliferation in the AVF outflow veins and a therapeutic target to improve the AVF patency rate.

Identification of Renal Transplantation Rejection Biomarkers in Blood Using the Systems Biology Approach.

Renal transplantation plays an essential role in the quality of life of patients with end-stage renal disease. At least 12% of the renal patients receiving transplantations show graft rejection. One of the methods used to diagnose renal transplantation rejection is renal allograft biopsy. This procedure is associated with some risks such as bleeding and arteriovenous fistula formation. In this study, we applied a bioinformatics approach to identify serum markers for graft rejection in patients receiving a renal transplantation. Transcriptomic data were first retrieved from the blood of renal transplantation rejection patients using the GEO database. The data were then used to construct the protein-protein interaction and gene regulatory networks using Cytoscape software. Next, network analysis was performed to identify hub-bottlenecks, and key blood markers involved in renal graft rejection. Lastly, the gene ontology and functional pathways related to hub-bottlenecks were detected using PANTHER and DAVID servers. In PPIN and GRN, SYNCRIP, SQSTM1, GRAMD1A, FAM104A, ND2, TPGS2, ZNF652, RORA, and MALAT1 were the identified critical genes. In GRN, miR-155, miR17, miR146b, miR-200 family, and GATA2 were the factors that regulated critical genes. The MAPK, neurotrophin, and TNF signaling pathways, IL-17, and human cytomegalovirus infection, human papillomavirus infection, and shigellosis were identified as significant pathways involved in graft rejection. The above-mentioned genes can be used as diagnostic and therapeutic serum markers of transplantation rejection in renal patients. The newly predicted biomarkers and pathways require further studies.

The Role of Ultrasound Examination in the Assessment of Suitability of Calcified Arteries for Vascular Access Creation-Mini Review.

Arterial calcifications are present in 20-40% of patients with end-stage kidney disease and are more frequent among the elderly and diabetics. They reduce the possibility of arterio-venous fistula (AVF) formation and maturation and increase the likelihood of complications, especially distal ischemia. This review focuses on methods for detecting arterial calcifications and assessing the suitability of calcified arteries for providing inflow before the construction of an AVF. The importance of a clinical examination is stressed. A grading system is proposed for quantifying the severity of calcifications in the arteries of the arm with B-mode and Doppler ultrasound exams. Functional tests to assess the suitability of the artery to provide adequate inflow to the AVF are discussed, including Doppler indices (peak systolic velocity and resistive index during reactive hyperemia). Possible predictors of the development of distal ischemia are discussed (finger pressure, digital brachial index, acceleration and acceleration time), as well as the outcomes of AVFs placed on calcified arteries. It is concluded that a noninvasive ultrasound examination is probably the best tool for a morphologic and functional assessment of the arteries. An arterial assessment is of utmost importance if we are to create distal radiocephalic AVFs in our elderly patients whenever possible without burdening them with futile surgical attempts.

Long-term patency of arteriovenous fistulas for hemodialysis: A decade's experience in a transplant unit.

The heterogeneous quality of studies on arteriovenous fistulas outcome, with variable clinical settings and large variations in definitions of patency and failure rates, leads to frequent misinterpretations and overestimation of arteriovenous fistula patency. Hence, this study aimed to provide realistic and clinically relevant long-term arteriovenous fistula outcomes. We retrospectively analyzed all autologous arteriovenous fistulas at our center over a 10-year period (2012-2022). Primary and secondary patency analysis was conducted using the Kaplan-Meier method; multivariate analysis of variance was used to detect outcome predictors. Vascular access-specific endpoints were defined according to the European guidelines on vascular access formation. Of 312 arteriovenous fistulas, 57.5% (n = 181) were radio-cephalic (RC_AVF), 35.2% (n = 111) brachio-cephalic (BC_AVF), and 6.3% (n = 20) brachio-basilic (BB_AVF). 6, 12, and 24 months follow-up was available in 290 (92.1%), 282 (89.5%), and 259 (82.2%) patients, respectively. Primary patency rates at 6, 12, and 24 months were 39.5%, 34.8%, and 27.2% for RC_AVF, 58.3%, 44.4%, and 27.8% for BC_AVF, and 40.0%, 42.1%, and 22.2% for BB_AVF (p = 0.15). Secondary patency rates at 6, 12, and 24 months were 65.7%, 63.8%, and 59.0% for RC_AVF, 77.7%, 72.0%, and 59.6% for BC_AVF, and 65.0%, 68.4%, and 61.1% for BB_AVF (p = 0.29). Factors associated with lower primary and secondary patency were hemodialysis at time of arteriovenous fistula formation (p = 0.037 and p = 0.024, respectively) and higher Charlson Comorbidity Index (p = 0.036 and p < 0.001, respectively). Previous kidney transplant showed inferior primary patency (p = 0.005); higher age inferior secondary patency (p < 0.001). Vascular access care remains challenging and salvage interventions are often needed to achieve maturation or maintain patency. Strict adherence to standardized outcome reporting in vascular access surgery paints a more realistic picture of arteriovenous fistula patency and enables reliable intercenter comparison.

How Does Surgeons' Autonomic Physiology Vary Intraoperatively?: A Real-time Study of Cardiac Reactivity.

To measure the physiological responses of surgical team members under varying levels of intraoperative risk. Measurement of intraoperative physiological responses provides insight into how operation complexity, phase of surgery, and surgeon seniority impact stress. Autonomic nervous system responses (interbeat intervals, IBIs) were measured continuously during different surgical operations of various complexity. The study investigated whether professional role (eg attending surgeon), operative risk (high vs. low), and type of primary operator (attending surgeon vs. resident) impacted IBI reactivity. Physiological synchrony captured the degree of correspondence between individuals' physiological responses at any given time point. A total of 10,005 observations of IBI reactivity were recorded in 26 participants during 16 high-risk (renal transplant and laparoscopic donor nephrectomy) and low-risk (arteriovenous fistula formation) operations. Attending surgeons showed greater IBI reactivity (faster heart rate) than residents and nurses during high-risk operations and while actively operating (Ps<0.001). Residents showed lower reactivity during high-risk (relative to low-risk) operations (P<0.001) and similar reactivity regardless of whether they or the attending surgeon was operating (P=0.10). Nurses responded similarly during low-risk and high-risk operations (P=0.102) but were more reactive when the resident was operating compared to when the attending surgeon was the primary operator (P<0.001). In high-risk operations, attending surgeons had negative physiological covariation with residents and nurses (P<0.001). In low-risk operations, only attending surgeons and nurses were synchronized (P<0.001). Attending surgeons' physiological responses were well-calibrated to operative demands. Residents' and nurses' responses were not callibrated to the same extent. This suggests that risk sensitivity is an adaptive response to stress that surgeons acquire.

Bioresorbable Mesenchymal Stem Cell-Loaded Electrospun Polymeric Scaffold Inhibits Neointimal Hyperplasia Following Arteriovenous Fistula Formation in a Rat Model of Chronic Kidney Disease.

Bioresorbable perivascular scaffolds loaded with antiproliferative agents have been shown to enhance arteriovenous fistula (AVF) maturation by inhibiting neointimal hyperplasia (NIH). These scaffolds, which can mimic the three-dimensional architecture of the vascular extracellular matrix, also have an untapped potential for the local delivery of cell therapies against NIH. Hence, an electrospun perivascular scaffold from polycaprolactone (PCL) to support mesenchymal stem cell (MSC) attachment and gradual elution at the AVF's outflow vein is fabricated. Chronic kidney disease (CKD) in Sprague-Dawley rats is induced by performing 5/6th nephrectomy, then AVFs for scaffold application are created. The following groups of CKD rats are compared: no perivascular scaffold (i.e., control), PCL alone, and PCL+MSC scaffold. PCL and PCL+MSC significantly improve ultrasonographic (i.e., luminal diameter, wall-to-lumen ratio, and flow rate) and histologic (i.e., neointima-to-lumen ratio, neointima-to-media ratio) parameters compared to control, with PCL+MSC demonstrating further improvement in these parameters compared to PCL alone. Moreover, only PCL+MSC significantly reduces 18 F-fluorodeoxyglucose uptake on positron emission tomography. These findings suggest that adding MSCs promotes greater luminal expansion and potentially reduces the inflammatory process underlying NIH. The results demonstrate the utility of mechanical support loaded with MSCs at the outflow vein immediately after AVF formation to support maturation by minimizing NIH.