Presentation on theme: "LA PATOLOGIA VASCOLARE DEGLI ARTI SUPERIORI:"— Presentation transcript:
1LA PATOLOGIA VASCOLARE DEGLI ARTI SUPERIORI: CORSO DI ECO COLOR DOPPLER VASCOLARE SIDV – GIUV - BERTINORO, 3 – 5 APRILE 2008LA PATOLOGIA VASCOLARE DEGLI ARTI SUPERIORI:FAV nei soggetti dializzati: valutazione della pervietà e parametri Doppler.D. Righi (Firenze)Carlo Ludovico Bompiani - Bertinoro
3GUIDELINE 3Selection of Permanent Vascular Access and Order of Preference for Placement of AV FistulaeA. The order of preference for placement of AV fistulae in patients with kidney failure who will become hemodialysis dependent is:1. A wrist (radial-cephalic) primary AV fistula (Evidence)2. An elbow (brachial-cephalic) primary AV fistula (Evidence/Opinion)B. If it is not possible to establish either of these types of fistula, access may be established using:1. An arteriovenous graft of synthetic material (eg, PTFE) (Evidence) or2. A transposed brachial basilic vein fistula (Evidence)C. Cuffed tunneled central venous catheters should be discouraged as permanent vascular access.
10Assessment of fistula maturation: In spite of the use of preoperative sonographic data to select vessels suitable for fistula construction, some fistulas still fail to mature adequately for dialysis use.There may be additional measurements obtained by preoperative Doppler ultrasound that predict clinically successful fistulas. These type of evaluations have not been addressed systematically, but may include a change in Doppler flow signal after fist clenching or a preoperative subclavian venous flow rate>400 mL/min.
11Radial-cephalic fistula with juxta-anastomotic stenosis Radial-cephalic fistula with juxta-anastomotic stenosis. (A) The affected segment of vein. (B) Postangioplasty treatment.Kidney International (2003) 64, 1487–1494
12Radial-cephalic fistula with large accessory vein Radial-cephalic fistula with large accessory vein. (A) Initial angiogram. A is cannulation site just above anastomosis. B is cephalic vein comprising fistula, and C is accessory vein arising from lateral aspect of fistula. (B) Angiogram performed postcoil obliteration. Arrow indicates location of coil.Kidney International (2003) 64, 1487–1494
17RadioGraphics, Vol 13, , 1993Duplex and color Doppler sonography of hemodialysis arteriovenous fistulas and graftsDE Finlay, DG Longley, MC Foshager and JG Letourneau. Although angiography has been the traditional method of imaging these vascular systems, duplex and color Doppler sonography offer a noninvasive method of evaluating dysfunctional hemodialysis access. In normally functioning fistulas, waveforms of flow in the supply arteries and throughout the graft are monophasic, with peak systolic velocities of cm/sec and end-diastolic velocities of cm/sec. The draining veins have arterial pulsations with peak velocities of cm/sec. Arterial and venous stenoses, graft thrombosis (occlusive and nonocclusive), infection, aneurysm and pseudoaneurysm formation, and arterial steal are relatively common abnormalities that can threaten or destroy graft function and can be diagnosed sonographically. Although abnormal hemodynamics in access fistulas are usually detected during hemodialysis, sonographic evaluation at the time of initial dysfunction may reveal an underlying correctable abnormality, and specific therapy may be instituted before the condition progresses. In addition, use of sonography may obviate an invasive angiographic examination if no significant hemodynamic problem is present.
18Radiology 2002;222:Management of Suspected Hemodialysis Graft Dysfunction: Usefulness of Diagnostic US.MC. Dumars, WE. Thompson, EI. Bluth, JS. Lindberg, M Yoselevitz, and Christopher R. B. Merritt, MDMATERIALS AND METHODS:. Patients were referred by the nephrology department when clinical findings were suggestive, but not obviously, of graft malfunction. Study results were deemed normal if flow volume exceeded 1,300 mL/min without significant visualized stenosis of 50% of the diameter or greater or if flow approached 1,300 mL/min without peak systolic velocity greater than 400 cm/sec.RESULTS: Of the 147 examinations, 49 (33%) had normal results, seven (5%) showed thrombosis at examination, and 91 (62%) had evidence of at least one significant visualized stenosis or diffuse notable degree of thrombus. Three patients with normal results required fistulography within 90 days, one for thrombosis. In the 91 studies with abnormal results, 69 patients underwent fistulography; results in 63 showed agreement, and three showed false-positive results. More central venous stenoses were found at fistulography than at US.CONCLUSION: US is a useful and reliable first step in managing clinically suspected hemodialysis graft stenosis. One-third of the studies showed no significant stenosis and did not require angiographic evaluation. US should be the initial study in patients suspected of having hemodialysis access dysfunction without exceptional evidence of stenosis
21DIGITAL SUBTRACTION ANGIOGRAPHY DEMONSTRATES A COMPLETE OCCLUSION OF THE FISTULA DRAINING VEIN AT THE ARTERIOVENOUS ANASTOMOSIS (ARROW)Kidney International (2000) 57, 1169–1175ANGIOGRAM AFTER MECHANICAL THROMBECTOMY WITH THE AMPLATZ DEVICE AND PTA. RECANALIZED FISTULA WITH EXCELLENT POSTPROCEDURAL FLOW (ARROWS) IS SHOWN.
22B-mode image of a thrombosis in the venous outflow tract, showing both fresh (low echogenicity) and older (high echogenicity) thrombotic materialCopyright restrictions may apply. Wiese, P. et al. Nephrol. Dial. Transplant :
23Joseph F. Polak, MD, MPH Director of Cardiovbascular Imaging, New England Medical Center, Boston MA with the assistance of: Jean M. Alessi-Chinetti, RVT, RDMS Technical Director Vascular Diagnostoic laboratory, Brigham and Women's Hospital, Boston MA
24Figure 1. The Tissue-Engineered Blood Vessel Preoperatively (Panel A), at 3 Months after Implantation (Panel B, Computed Tomographic Angiography), and at 12 Months after Implantation (Panel C, Doppler Ultrasonography). VA denotes venous anastomosis, and AA arterial anastomosis.Nov. 2007