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.

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.

Acute problems of hemodialysis access: Thrombosis, aneurysms, symptomatic high-flow fistulas, and complications related to central lines.

Hemodynamic complications frequently affect vascular access and are important causes of morbidity and mortality. We present a review of acute complications affecting vascular accesses, focusing on classical and new treatments. Acute complications in hemodialysis vascular access are often underestimated and undertreated, and can present a challenge for both vascular surgeons and anesthesiologists. Accordingly, we considered different anesthesiologic approaches to both hemorrhagic and nonhemorrhagic patients. A strict collaboration among nephrologists, surgeons, and anesthesiologists can potentially improve prevention and management of acute complications and quality of life.

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.

Outcomes Analysis of Surgical Conversion for Kissing-Stent Occlusion.

BACKGROUND: We aimed to describe the operative outcomes following open aortoiliac/femoral graft reconstruction for bilateral kissing-stent (KS) occlusion. METHODS: This is a bicentric, retrospective, observational cohort study. Between September 2007 and December 2019, 205 patients were treated with KS for aortoiliac reconstruction. Only those who had bilateral KS occlusion with subsequent aortoiliac/femoral graft replacement were included in this analysis. Primary outcomes were early (<30 days) and late survival, postoperative (<30 days) complications, and patency rates. RESULTS: Nine patients (male, n = 7) were analyzed. The patient's mean age was 60 ± 5 years (range 55-62). Median delay from initial KS procedure was 36 months (interquartile range [IQR] 19-252). On admission, all patients presented with a worse Rutherford class compared to their initial pre-KS clinical presentation. Aortobifemoral bypass was performed in 5 patients, and aortobi-iliac reconstruction in 4 patients. There were no perioperative deaths and only 1 new case of erectile dysfunction occurred. At a median follow-up time of 24 months (IQR 12-54), primary patency rate was 88.9%. CONCLUSIONS: Open aortic reconstruction after KS occlusion was feasible and effective. Endovascular repair for aortoiliac obstructive disease may be pursued as first-line treatment even in complex lesions.

Plasmablastic lymphoma presenting as a brachial artery aneurysm associated with haemodialysis arteriovenous access ligation in a renal transplant patient.

INTRODUCTION: Plasmablastic lymphoma is a rare and aggressive neoplasm, generally associated with immunodeficiencies and related to latent Epstein-Barr virus infection. This case is the first reported case of plasmablastic lymphoma relapse in aneurysmatic brachial artery wall. CASE DESCRIPTION: We describe the case of male patient who underwent cadaveric donor kidney transplant when he was 61 years old and radio-cephalic distal arteriovenous fistula ligation 8 months later. After 8 years, he developed gingival plasmablastic lymphoma treated with cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone regimen with subsequent remission. During follow-up, a mid-forearm vascular access was created because of the worsening of renal function. Twenty-two months later, the patient showed a symptomatic 20 mm brachial artery aneurysm with radiological signs of imminent rupture, for which he was surgically treated. The histological evaluation of the brachial artery specimen revealed a relapse of plasmablastic lymphoma in the arterial wall and in an adjacent lymph node. CONCLUSION: Brachial artery aneurysms are a rare complication in kidney transplant recipients after ligation of arteriovenous access for haemodialysis. Here, we report a case in which this condition is associated with an even rarer plasmablastic lymphoma. A common aetiology, due to immunosuppressive therapy, is postulated for the two coexisting diseases.

Drug-coated balloon angioplasty in failing haemodialysis arteriovenous shunts: 12-month outcomes in 200 patients from the Aperto Italian registry.

BACKGROUND: We evaluated the safety and technical and clinical outcomes of angioplasty with a drug-coated balloon for the management of venous stenosis in arteriovenous grafts and arteriovenous fistulas in patients undergoing haemodialysis. METHODS: Data were obtained from an ongoing prospective, non-randomised registry conducted at three Italian centres. Patients were treated with a drug-coated balloon according to standard procedures in each participating centre. Evaluation was by colour Doppler imaging every 3 months. The primary end-point was primary assisted patency. The secondary end-point was the rate of assisted patency of the vascular access. RESULTS: A total of 311 angioplasty procedures in 200 patients, (60.4% male), were analysed. The procedural success rate was 100%. A total of 192 treatments of restenosis were necessary in 81 patients during average 21 ± 8 months follow-up. Kaplan-Meier estimates indicated that 88.0%, 64.2% and 40.6% of treated lesions were free from restenosis at 6, 12 and 24 months, respectively. Including multiple angioplasty, circuit patency rates were 99.2%, 92.5% and 84.8% at 6, 12 and 24 months, respectively. Primary patency rates were highest in shunts treated de novo with drug-coated balloons. Risk of restenosis was associated with circuit age (p = 0.017), history of treatment with conventional angioplasty (p < 0.001) and the kind of balloon used during pre-dilation (p = 0.001). CONCLUSION: The results suggest that favourable long-term patency rates can be achieved with the drug-coated balloon in a varied population of patients with failing haemodialysis arteriovenous shunts treated under conditions of actual care.

Outcomes Following Non-operative Management of Thoracic and Thoracoabdominal Aneurysms.

BACKGROUND: Surgical decision making remains difficult in several patients with aneurysmal disease of the descending thoracic (DT) or thoracoabdominal (TA) aorta. Despite previous studies that have investigated aneurysms treated non-operatively using a prospective growth analysis, completeness and accuracy of follow-up were inconsistent. We aim to describe the survival and freedom from adverse aortic events in patients with DT and TA who did not undergo operative repair. METHODS: This is a single-center retrospective analysis of all patients with either a descending degenerative atherosclerotic or dissection-related DT or TA aortic lesion who were treated non-operatively from April 2002 to December 2016. We studied patients who did not undergo operative repair of descending degenerative atherosclerotic or dissection-related DT or TA aortic lesion. Primary end points were overall survival and freedom from aortic-related mortality (ARM). RESULTS: Of the 315 patients diagnosed with DT or TA disease, 56 (18%) did not undergo surgical repair. Mean aneurysm diameter was 65 mm ± 15 (range 50-120; IQR 5.4-7.15). Extent of the aortic aneurysms was DT in 36 (11%) patients and TA in 20 (6%). Median duration of follow-up was 12 months (range 1-108; IQR 3-36). Over the course of the study, 41 (73%) patients died for an overall survival rate of 53% ± 7 at 1 year (95% CI 40-65) and 23% ± 7 at 3 year (95% CI 17-42.5). Aortic-related mortality was 27% (n = 15), significantly higher in patients with aneurysms ≥ 60 mm [n = 13, (39%) vs. n = 2, (9%); P = 0.025; OR = 5.04]. Overall, estimated freedom from ARM was 81% ± 5.5 at 1 year (95% CI 68-89) and 66.5% ± 9 at 3 year (95% CI 48-81). Only TA extent was independently associated with freedom from ARM during the follow-up (P = 0.005; HR: 5.74; 95% CI 1.711-19.729). CONCLUSIONS: Thoracoabdominal extent of the aneurysmal aortic disease is the most important predictor of ARM in unrepaired DT or TA aortic diseases. Mortality from aortic-related events was significantly more premature than mortality from non-aortic-related mortality.