Implanted blood vessel external support device for the treatment of distal hypoperfusion ischemic syndrome in arteriovenous fistulas and high-frame-rate Vector Flow quality assessment.

INTRODUCTION: Distal hypoperfusion ischemic syndrome (DHIS) is a complication occurring after arteriovenous fistula (AVF) creation. Different surgical alternatives haves been proposed in case of severe DHIS. Aim of the present paper is to present a new technique for DHIS treatment. MATERIAL AND METHODS: Between the 1st of January 2021 and the 31st December 2021 all the patients referred to our center for DHIS grade 2-4 were treated with a new surgical technique. It consists of AVF remodeling using an external nitinol support (VasQ®) to reduce the risk of outflow vein enlargement and DHIS recurrence. To better appreciate the hemodynamic effects of the surgery, a new ultrasound technique called high-frame-rate Vector Flow (HiFR-VF) was used. RESULTS: Seven patients (M:F 1:3; mean age 43 ± 12 years, range 29-65) were included in this study. Central line was never necessary, and technical success was 100% at 12 months. The comparison with historical data demonstrated lower recurrence of symptoms in comparison to simple artery-to-vein redo (p 0.50). The HiFR-VF showed flow with limited turbulent characteristics at the anastomosis site. DISCUSSION AND CONCLUSION: The new technique proposed demonstrated to be safe and effective for treatment of DHIS, preventing symptoms recurrence. Ultrasound examination and HiFR-VF can be considered a valuable method to evaluate complex flows at the levels of vascular anastomosis.

Proposal of a classification of cannulation damage in vascular access grafts based on clinical, ultrasound, and microscopic observations.

INTRODUCTION: Arteriovenous grafts (AVGs) serve as an alternative to native arteriovenous fistulas (AVFs) in the context of hemodialysis patient life planning. AVGs are more susceptible to developing outflow stenosis (due to intimal hyperplasia), thrombosis, and infections. However, an often overlooked contributor to AVG failure is cannulation damage. The objective of this paper is to assess the impact of cannulations on AVGs. We aim to establish a classification of AVG damage by comparing clinical data and ultrasound images with microscopic morphological findings obtained from explanted grafts. MATERIALS AND METHODS: This study is conducted at a single center. We included all patients who underwent AVG creation between 2011 and 2019. Comprehensive data on clinical history, follow-up, and complications were collected and reviewed. Duplex ultrasound (DUS) characteristics were documented, and all grafts explanted during the analysis period underwent optical microscopy evaluation. Finally, clinical data, along with DUS and microscopic findings, were integrated to derive a damage classification. RESULTS: During the study period, 247 patients underwent 334 early cannulation AVGs. The median follow-up duration was 714 days (IQR 392, 1195). One hundred eleven (33%) grafts were explanted. Clinical data and DUS findings were utilized to formulate a four-grade classification system indicating increasing damage. CONCLUSION: Cannulation damage alone does not solely account for AVG failure. It results from a biological host-mediated process that promotes the growth of intimal hyperplasia at the cannulation sites. This process is not clinically significant within the initial 2 years after AVG creation.

Systemic inflammation index as useful tool to predict arteriovenous graft stenosis: Our experience and literature review.

OBJECTIVE: Many studies show that settings of severe inflammatory stress might be responsible for changes in circulating blood cells count. Effective inflammation indices are created calculating the quantitative relationship between these cells. No previous studies have been proposed on hemodialysis patients exploring the association between arteriovenous graft (AVG) stenosis and systemic inflammation markers, such as Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and systemic-immune-inflammation index (SII). METHODS: Patients undergone surgery for AVG creation in a 2-year period are examined. Examining their full blood count, we have established the value of inflammatory indices (NLR, PLR, SII) and we have compared their mean values in patients who have developed significant stenosis or not. Finally, we have considered the connection between those values and stenosis onset and recurrence in AVG. RESULTS: Fifty-two patients are included in the study [male: 40%, mean age 70 ± 15 years (range 55-86)]. We have found out there is not statistical significance in preoperative values of inflammatory index (NLR p 0.33, PLR p 0.15, SII p 0.98) Otherwise NLR and SII indices were statistically significant 3 months after surgery (NLR 2.04 ± 0.98 vs 3.91 ± 2.10, p < 0.001; SII 415.32 ± 255.15 vs 636.91 ± 349.01, p 0.014). CONCLUSIONS: Increased post-operative values of NLR and SII have proved a strong association with AVG outflow stenosis onset and recurrence.

Carbon dioxide automated digital subtraction angiography for endovascular arteriovenous fistulas creation.

Recent literature shows how residual renal function (RKF), defined as the urinary clearance of urea and creatinine, is associated with a lower mortality risk in HD patients. The use of non-nephrotoxic contrast media during radiological procedure, may be useful for preservation of RKF in patients with chronic kidney disease not yet in haemodialysis. We describe the case of a 51-year-old male suffering from chronic kidney disease from 2018, due to a right nephrectomy for an adenocarcinoma, who was considered for an endovascular arteriovenous fistula (endoAVF) creation (WavelinQ endoAVF System, Becton Dickinson, Franklin Lakes, New Jersey, US), using Carbon Dioxide as contrast media instead of conventional iodinated ones, with optimal results. CO2 DSA permits to well recognize the patency of target vein, its connection to the perforator vein and finally the endoAVF creation without requiring supplemental iodate contrast medium. We propose, CO2 automated digital subtraction angiography (DSA) as a safer technique that could be substitutive of the standard iodinated ones, in the creation of endo AVF.

Stent migration as complication of endovascular treatment of vascular access stenosis: A systemic review.

Outflow vein stenosis is one of the commonest complications of both native and prosthetic vascular access. Together with angioplasty, first-line treatment is stenting. Although it has been described as a uncommon complication, the risk of stent migration should be always considered. We aimed to conduct a systematic review of literature concerning stents migration in vascular access, the possible outcomes and treatments. This study was performed applying Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches were conducted in PubMed/Medline, Scopus, and Google scholar databases. Studies selection, data abstraction was done by two different reviewers. We identified 17 studies, comprising 18 cases (M:F 1:1, mean age 56 ± 18 (range 33-88)). All the patients underwent stenting for vascular access outflow stenosis. The commonest type of device reported was self expandible bare-metal stent. Intraoperative evidence of stent migration occurred in six cases at the final quality control, or for intraprocedure dyspnea onset. In two patients it was a incidental diagnosis. In the remaining cases, chest pain or dyspnea were the common delayed presentation symptoms. Even if stent migration is an uncommon event, it is burdened with low mortality and morbidity. Literature provide only few and frequently inadequate data. Stent removal is the treatment of choice when severe symptoms or cardiopulmonary complication are present. Endovascular procedures demonstrated to be an effective and safe alternative, while open surgical treatment is preferred whenever endovascular therapy failed or in selected cases.

Reaction and movement times in individuals with chronic traumatic brain injury with good motor recovery.

Reaction times and movement times were studied in 18 individuals with severe traumatic brain injury (TBI) and 36 matched normal controls. Reaction times depended on the type of task: in the case of simple visual stimuli (Alertness condition) they were similar in individuals with TBI and normal controls. In contrast, individuals with TBI were slower in a Go-no-go test. Regardless of task, movement times depended on movement length and were slower in individuals with TBI. These findings indicate the presence of a residual motor programming deficit in individuals with TBI even in the chronic stage and in the presence of good motor recovery, as assessed clinically.