Severe Endothelial Damage in Chronic Kidney Disease Patients Prior to Haemodialysis Vascular Access Surgery

Abstract

Background: Hemodialysis as an efficient therapy for advanced CKD is the most used treatment modality all over the world. Even though primary AVF is widely accepted as a best permanent vascular access in hemodialysis patients, up to 60% of all fistulas fail to mature. The pathogenesis of early fistula failure is not very well understood. Many general and local factors are involved: patient's age, sex, primary renal disease, small vessel's diameter, presence of accessory veins, prior venipunctures, surgical skill, genetics, etc. Histological investigations have confirmed the neointimal venous hyperplasia as a major pathological finding in stenotic lesions of AVF failure, due to local inflammation, oxidative stress and migration and proliferation of myofibroblasts, fibroblasts and endothelial cells. Materials and methods: A total of 89 patients with stadium 4-5 of CKD are involved in the study. A typical radio-cephalic AVF is created in all patients. Part of the fistula vein was taken for histological, immunohistochemical (Vimentin, TGF  and KI67) and morphometric analysis. Appriopriate statistical method was applied. Results: Up to 80% of the patients showed some degree of endothelial changes at the time of creation of AVF, among them 19 pts with substantial intimal hyperplasia, 51 with medial hypertrophy and 19 pts with normal histology. Almost two thirds of the patients did not have expression of TGF. More than 95% had some expression of Vimentin. None of the patients had expression of the marker KI 67. Conclusion: Medial hypertrophy is predominant preexisting pathohistological lesion prior the AVF creation, despite the presence of neointimal hyperplasia. The absence of TGF expression in majority of our patients could suggest that inflammation and oxidative stress are developing later, after vascular access surgery. The dominant cells within the stenosis in the veins are myofibroblasts. Their increased presence maybe a reason why some patients are prone to developing venous endothelial changes as a results of exaggerated vascular endothelial response to the effect of uremia, hypertension and other insults.

Primary Failure of the Arteriovenous Fistula in Patients with Chronic Kidney Disease Stage 4/5

“…The process of AVF maturation is complex and remains poorly understood, despite numerous studies describing the pathophysiology of the process and biomechanical factors associated with maturation. The intimal hyperplasia (IH) has been identified as the main pathohistological change, which occurs in the blood vessels and was associated with the primary failure of AVF [13]. However, the creation of AVF is the first step for the patients who need a functional permanent VA for HD.…”

Occurrence of adverse events in public hemodialysis units

“…Los problemas asociados a la disfunción del AV son la causa más común de aumento de la morbilidad, mortalidad e ingresos hospitalarios de los pacientes en HD, resultando en grandes cargas clínicas, sociales y financieras, incluso para los países desarrollados. (21) Los pacientes con más de cinco años de HD poseen mejores marcadores de calidad de vida cuando comparados a los pacientes con menor tiempo de tratamiento. (22) El buen nivel de comprensión de la enfermedad y de los aspectos del tratamiento también influyen positivamente en la adaptación del paciente y su adhesión al tratamiento.…”