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The cardiovascular system
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
Mary N Sheppard, C. Simon Herrington
The finding post mortem of an aneurysmal dilatation of a long segment of one or more coronary arteries needs careful consideration of a number of causes. Localized aneurysms are mainly atherosclerotic in elderly individuals, but may also be congenital, or occur as a result of Kawasaki's disease (see Special Study Topic 7.1) or trauma. Traumatic penetration may cause a false aneurysm, which is the fibrous wall of an organized haematoma communicating with the arterial lumen. Trauma to adjacent arteries and veins may lead to an arteriovenous fistula. A carotid–cavernous sinus fistula may follow a skull fracture. Proptosis is due to venous engorgement and orbital oedema. A cirsoid or racemose aneurysm is an arteriovenous fistula that forms a pulsatile swelling, comprising tortuous and dilated arteries and veins with multiple intercommunications. It is most common in the scalp after birth injury or other trauma.
Urinary system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Some patients with end-stage renal failure require haemodialysis. Ideally this is achieved by the surgical creation of an arteriovenous fistula, typically in the patient’s non-dominant arm. Common sites of fistulae include connection of the radial artery with the cephalic vein at the wrist, or the brachial artery with the cephalic vein or basilic vein at the elbow. As the vein receives high pressure blood directly from the artery, it arterialises (‘matures’), enlarging and becoming thicker walled. Flow though the fistula may be clinically noticeable as a palpable ‘thrill’ (a buzz). This large vein provides easier long term access for the large gauge dialysis needles and allows continuous high volumes of blood flow necessary for efficient dialysis. However, over time stenoses may develop, often around the site of the anastomosis or the needling sites; this can cause reduced blood flow, and if untreated can lead to suboptimal dialysis and/or thrombosis of the fistula. Stenoses may be treated by angioplasty, while thrombosis, if diagnosed early enough, may be treated with thrombolysis, mechanical or aspiration thrombectomy or ‘trawling’ the thrombus with an angioplasty balloon. Alternative access for haemodialysis may be provided via a tunnelled central venous catheter. In difficult cases this can be inserted under radiographic control.
Vascular Access
Published in James L. MacPherson, Duke O. Kasprisin, Therapeutic Hemapheresis, 2019
Due to the emergency nature of most therapeutic apheresis procedures, arteriovenous fistulas are not widely used; however, they are the procedure of choice for long-term vascular access. Internal fistulas require a six- to eight-week postoperative period to allow for maturation of the anastomosed artery and vein.
Contemporary review of management techniques for cephalic arch stenosis in hemodialysis
Published in Renal Failure, 2023
Gift Echefu, Shivangi Shivangi, Ramanath Dukkipati, Jon Schellack, Damodar Kumbala
According to the Kidney Disease Outcomes Quality Initiative statement, primary patency refers to the absence of vascular access dysfunction, patent lesion or residual stenosis <30% with no indication for further reintervention of the lesion [35]. Assisted primary patency is the interval from the time of access placement to the time of access thrombosis requiring surgical or endovascular interventions to maintain access patency. Secondary patency, therefore, refers to patency occurring between the time of primary intervention and the time when the AV access is revised or abandoned [35,36]. The long-term patency of arteriovenous fistulas is influenced by several factors such as timely referral for placement of fistula, collaborative approach of team to secure the access, continuous quality assessment and practicing routine pre-operative mapping of arteries and veins.
Prognosis and risk factors for cardiac valve calcification in Chinese end-stage kidney disease patients on combination therapy with hemodialysis and hemodiafiltration
Published in Renal Failure, 2022
Jian-qiong Xiong, Xue-mei Chen, Chun-ting Liang, Wen Guo, Bai-li Wu, Xiao-gang Du
In total, 293 patients underwent regular hemodialysis for 4 h twice a week and online hemodiafiltration for 4 h once a week using a Helixone Haemodlafilter FX 800 (Surface Are: 1.8 m2) or NIPRO Hollow fiber dialyzer FB-150U (Surface Area: 1.5 m2) combined with intermittent hemoperfusion once every month using the Jafron HA130 disposable hemoperfusion system. Blood purification was conducted on a Fresenius Medical Care 4008s or GAMBRO AK96 hemodialysis machine. Autogenous arteriovenous fistulas were the preferred route for vascular access followed by arteriovenous grafts or venous catheters. The patient’s blood was extracted at a blood flow rate of 230–280 mL/min. All dialysate calcium concentrations were not greater than 1.25–1.50 mmol/L. All patients received conventional drug therapy, such as antihypertensive treatment with calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), calcium and phosphorus-regulating treatment with a calcium-containing phosphorous binder or alfacalcidol tablets, anti-anemia treatment with iron preparations or recombinant human erythropoietin (EPO).
Surgical and non-surgical approaches in the management of lower limb post-thrombotic syndrome
Published in Expert Review of Cardiovascular Therapy, 2021
M Machin, S Salim, M Tan, S Onida, AH Davies, J Shalhoub
Surgical thrombectomy has fallen out of practice with the advancement in catheter-directed therapies, with numbers at rock-bottom in the UK since the early 2000s with as few as 26–45 procedures performed annually [15]; it is likely that even these few open thrombectomy procedures are not exclusively related to primary DVT and include cases for restoring flow within venous bypass grafts. Although no longer routinely practiced, some centers in Europe still undertake surgical thrombectomy; hence, it will be briefly mentioned here. The usual technique is to perform a surgical cut down to the common femoral vein as a minimum, with addition of access to the crural veins such as the posterior tibial vein if required [24]. If there is involvement of the inferior vena cava, a proximal filter is usually placed to avoid pulmonary embolization during thrombectomy. Intra-operative venography is used to visualize the obstruction and aid passage of the Fogarty catheter. The catheter is passed to a cephalad point prior to balloon inflation and thrombectomy undertaken. Intra-operative injection thrombolysis and stenting procedures can also be undertaken as an adjunct to open surgical thrombectomy. A surgical arteriovenous fistula can be created at the femoral vessels to improve venous patency.