Embolization for fistulas and arteriovenous malformations
Debabrata Mukherjee, Eric R. Bates, Marco Roffi, Richard A. Lange, David J. Moliterno, Nadia M. Whitehead in Cardiovascular Catheterization and Intervention, 2017
An arteriovenous fistula is an abnormal connection between an artery and a vein. As a consequence, the blood bypasses the capillary bed. The majority of arteriovenous malformations (AVMs) are congenital, but some can be acquired due to trauma, infection, or malignancy. An arte- riovenous fistula (AVF) may be the result of a vascular cath- eter insertion or may be created surgically to provide access for hemodialysis in patients with end-stage kidney failure. AVMs can occur anywhere in the body, including the cen- tral nervous system. Congenital AVMs are present at birth, and although they may be asymptomatic, they always per- sist and do not involute,1, 2 unlike true hemangiomas. AVMs may become symptomatic with age, sometimes at puberty in female patients, during pregnancy, or after trauma. Of special interest are pulmonary AVMs, mostly related to hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome), a condition that is discussed later in the chapter.
Practice Paper 7: Answers
Anthony B. Starr, Hiruni Jayasena, David Capewell, Saran Shantikumar in Get ahead! Medicine, 2016
An arteriovenous fistula is formed when a surgical anastomosis is formed between a vein and a neighbouring artery. The fistula provides easy access to high flow rates amenable to haemodialysis. During haemodialysis, two needles are inserted into the fistula. One needle removes blood from the circulation and delivers it to the dialysis machine, while the other returns the dialysed blood to the patient. Steal syndrome occurs when too much blood enters the fistula at the expense of distal tissues, i.e. the hand and fingers in radiocephalic fistulas. The diminished arterial blood supply to the hand causes discoloration, pain, cramps and paraesthesiae, with tissue ischaemia and necrosis in severe cases. In addition, the patient will have a weak radial pulse and a low brachial–wrist pulse index. Other complications involving arteriovenous fistulas include thrombosis and aneurysm formation.
Surgical and endovenous treatment of superior vena cava syndrome
Peter Gloviczki, Michael C. Dalsing, Bo Eklöf, Fedor Lurie, Thomas W. Wakefield, Monika L. Gloviczki in Handbook of Venous and Lymphatic Disorders, 2017
The technique of endovenous repair involves ultrasound-guided percutaneous venous access of the common femoral vein and placement of 6–10-Fr sheaths followed by crossing the stenotic/occlusive lesion with hydrophilic guidewires and catheters. The right internal jugular/arm vein can be an alternative or additional venous access site in patients with short focal lesions or if the lesion cannot be crossed from the femoral approach, respectively. Access of a hemodialysis arteriovenous fistula, if present, is a viable option. Long sheaths extending to the site of a long occlusion can be helpful in providing the necessary support to cross the lesion. Once wire access across the lesion is obtained, primary PTA using standard 10–16-mm angioplasty balloons is performed, followed by stenting. Choice of stent is tailored to the etiology, degree, length, and tortuosity of the SVC stenosis. Venous stenoses can be very resistant, often requiring angioplasty with high-pressure balloons (e.g., Mustang [Boston Scientific Inc., USA] or ATLAS [Bard Peripheral Vasc Inc., AZ, USA]). Perforation can occur during this process, and if minor—manifesting as a mild perivenous blush without hemodynamic changes—can be managed successfully with prolonged balloon inflation. Placement of a covered stent is required to control larger, more significant perforations, especially if associated with hemodynamic instability.36 Rarely, SVC rupture can result in pericardial tamponade. Rapid diagnosis and immediate ultrasound-guided pericardial drainage is necessary.37
Degree of Soft Tissue Injury is a Major Determinant of Successful Arterial Repair in the Extremity: A New Classification of Extremity Arterial Injury?
Published in Journal of Investigative Surgery, 2022
Peijun Deng, Jiantao Yang, Jacques Henri Hacquebord, Bengang Qin, Honggang Wang, Ping Li, Liqiang Gu, Jian Qi, Qingtang Zhu
Vascular injury is classified into 5 types: 1) intimal injury, 2) complete wall defect, 3) complete transection, 4) arteriovenous fistula, 5) spasm [1]. Although not specific to extremity arterial injury, this classification system is effective in guiding vascular repair methods when the surrounding soft tissue is stable and healthy [10–12]. However, when extremity arterial injury is associated with soft tissue injury, vascular repair techniques are complex [1, 6]. A variety of vascular repair methods can be used to treat extremity arterial injury, including direct vessel suture, autogenous or artificial vessel graft, and endovascular repair [13]. Uncommon but previously described techniques include flow-through flap transplantation and temporary ectopic implantation [14, 15]. There are several classifications of soft tissue injury, including the Tscherne Classification of Soft Tissue [16], AO Soft Tissue Grading System, and Ganga Hospital Open Injury Score [17]. However, these do not specifically apply to extremity arterial injury or guide treatment.
Effects of intradialytic resistance training on physical activity in daily life, muscle strength, physical capacity and quality of life in hemodialysis patients: a randomized clinical trial
Published in Disability and Rehabilitation, 2020
Felipe Martins do Valle, Bruno Valle Pinheiro, Ariane Aparecida Almeida Barros, William Ferreira Mendonça, Ana Carla de Oliveira, Gustavo de Oliveira Werneck, Rogério Baumgratz de Paula, Maycon Moura Reboredo
The study sample included adult ESRD patients who were under chronic hemodialysis treatment, three times per week totaling 12 h weekly, for at least three months in the Nephrology Unit of the University Hospital at the Federal University of Juiz de Fora, Brazil. The dialysis vascular access was arteriovenous fistula for all the patients. No patient had been involved in exercise training in the preceding six months, and none was classified as physically active according to the “International Physical Activity Questionnaire” [19]. Exclusion criteria were the presence of any limitation that prevents the physical tests, presence of severe and unstable comorbidities or hospitalization in the three months prior to inclusion in the study. The following clinical conditions were considered severe or unstable comorbidities: unstable angina; decompensated heart failure; myocardial infarction in the last six months; uncontrolled arrhythmia; uncontrolled hypertension with systolic blood pressure ≥ 200 mmHg and/or diastolic blood pressure ≥ 120 mmHg; uncontrolled diabetes; severe pneumopathies; acute systemic infection; neurological, musculoskeletal and disabling osteoarticular disturbances; or other conditions according to clinical judgment. The study protocol followed the ethical principles of the Declaration of Helsinki, and was approved by the Federal University of Juiz de Fora Research Ethics Committee (protocol number 1.233.083), and registered in Clinical Trials (NCT02651025). All patients signed an informed consent term.
Radial augmentation index may be an effective predictor of vascular calcification in patients on peritoneal dialysis
Published in Renal Failure, 2020
Ning Yang, Wei Yang, Wenting Cui, Dan Zhou, Xiangning Du, Longkai Li
Nishiura and coworkers showed that RAI was significantly higher in patients undergoing HD than in HCs (p < 0.001). Multiple regression analysis showed that RAI was significantly associated with AACI [15], but carotid artery IMT was not measured in their study. Therefore, the findings of Nishiura and colleagues, and the findings of our study suggest that RAI was closely associated with VC, not only in patients undergoing HD, but also in patients undergoing PD. RAI could be applied to screen for VC in patients undergoing PD. However, arteriovenous fistula of the arms is used frequently for vascular access in hemodialysis dialysis. RAI might not be measured in the same arm when RAI is compared, and some patients undergoing HD may have no measurement results because of arteriovenous fistulas in both arms. It may be better to measure RAI to evaluate VC in patients undergoing PD (without arteriovenous fistula in the arms).
Related Knowledge Centers
- Aneurysm
- Birth Defect
- Hemodialysis
- Hereditary Hemorrhagic Telangiectasia
- Vein
- Artery
- Pathology
- Injury
- Intracranial Aneurysm
- Cerebral Arteriovenous Malformation