Ultraljudsundersökning vid accessproblem

Transkript

1 Ultraljudsundersökning vid accessproblem Madeleine Lindqvist Klinisk Fysiologi Karolinska Universitetssjukhuset

2 AV-fistel arm Accesstyper 1 handledsnivå: a.radialis-v.cephalica 2 distalt överarm: a.brachialis-v.cephalica Graft a brachialis- v basilica 3 Underarm -- loopgraft eller rakt graft 4 Överarm -- loopgraft eller rakt graft 5 mm 6 AV-fistel ljumske 7 Temporär central kateter (undviks så länge som möjligt pga infektionsrisk och stenosrisk)

3 Övervakning av dialysaccesser Regelbunden flödesmätning vid dialys Mätning av ventryck Trender snarare än absolutvärden NKF-KDOQI Guidelines 2006 (National Kidney Foundation Kidney Disease Outcomes Quality Initiative)

4 Hemodialysis vascular access surveillance continues to be widely recommended despite ongoing controversy as to its benefit in prolonging access patency compared with clinical monitoring alone. The most common screening tests are access blood flow and dialysis venous pressure measurements. When surveillance test results cross a predetermined threshold, accesses are referred for intervention with correction of stenosis to reduce future thrombosis and prolong access survival. Current surveillance strategies have four components: (1) underlying condition; (2) screening test; (3) intervention; and (4) outcomes. However, limitations exist within each component that may prevent achieving the desired outcomes. This review discusses these limitations and their consequences. To date, randomized controlled trials have not consistently shown that surveillance improves outcomes in grafts, and there is limited evidence that surveillance reduces thrombosis without prolonging the life of native fistulae. In conclusion, current evidence does not support the concept that all accesses should undergo routine surveillance with intervention. Vascular access surveillance: an ongoing controversy William D Paulson 1, Louise Moist 2 and Charmaine E Lok 3 Kidney International (2012) 81, ; doi: /ki ; published online 5 October 2011

5 Vascular access dysfunction continues to be a major cause of morbidity and mortality in the end-stage renal patient. Thrombosis is the primary cause of prosthetic arteriovenous access (ie, graft) failure caused by the progressive development of neointimal hyperplasia, which eventually leads to a stenosis, usually at the venous anastomosis. More than 20 years ago, observational studies using a variety of surveillance techniques, coupled with preemptive angioplasty, convincingly demonstrated the ability to detect venous stenosis, and elective treatment of stenoses significantly decreased both thrombosis and access loss. Although multiple observational studies have shown a benefit from surveillance, these studies generally had no control population, used historical controls, or used incorrect statistical analysis. However, five randomized controlled trials that evaluated the effect of graft surveillance coupled with preemptive angioplasty have failed to demonstrate a benefit on graft outcomes, including prolongation of graft survival. This review will examine the role of access surveillance and preemptive angioplasty in achieving the goal of reducing vascular access thrombosis and prolonging access survival. Work, MD, Role of access surveillance and preemtive intervention. Semin Vasc Surg 24: Elsevier Inc. All rights reserved.

6 Duplex vid accessproblem Sjunkande flöden (Transonic, mäts regelbundet i samband med dialys) Lågt artärtryck ( artärsug ) Högt ventryck Lång blödningstid Armsvullnad Lokal svullnad

7 Accessproblem (forts) Fisteln utvecklas aldrig (20-30%) OBS! Diabetiker, Kvinnor Trombos Infektion Pseudoaneurysm Steal och digital ischemi Kardiell insufficiens

8 Undersökning av dialysaccess Follow the blood cell Artärsidan från a subclavia-fistel/graftvensidan tom v subclavia/brachiocephalica Volymsflöde i a brachialis B-mode för morfologi Spektraldoppler-hastighet och flödesprofil Färgdoppler-stenoser, pseudoaneurysm

9 Defining a Significant Stenosis in an Autologous Radio Cephalic Arteriovenous Fistula for Hemodialysis Fahrtash, F, et al. Seminars in Dialysis Volume 24, Issue 2, pages , 25 APR 2011

10 Fynd Volymsflöde- för högt eller för lågt artärstenos anastomoser venstenos tromber vengrenar aneurysm pseudoaneurysm

11 Volymsflöde Litet blodflöde i a brachialis- för fungerande dialys bör flödet vara minst ml/min för fistel, >800ml/min för graft. Stort blodflöde i a brachialis - kan vara förenat med stealfenomen- över 1500ml/min - kan leda till högerkammarbelastning och svikt

12 Högresistensprofil-normalt volymsflöde- men ej normalt för dialysaccess Lågresistensprofil-stort volymsflöde

13 Bay et al, Am J Nephrol 1998; 18:

14 Stenos Vanligaste orsaken till accessdysfunktion Typisk lokalisation-i venen nära anastomosen, flödesbetingad neointimal hyperplasi I fistelvenens stickområde Proximal stenos (inflödet i djup ven) V subclavia efter CDK Stenos på artärsidan-fr a hos diabetiker Graft/venanastomos

15 Vad är en stenos?

16 Defining a Significant Stenosis in an Autologous Radio Cephalic Arteriovenous Fistula for Hemodialysis Fahrtash, F, et al. Seminars in Dialysis Volume 24, Issue 2, pages , 25 APR 2011

17 Defining a Significant Stenosis in an Autologous Radio Cephalic Arteriovenous Fistula for Hemodialysis Seminars in Dialysis. Fahrtash, F, et al. Volume 24, Issue 2, pages , 25 APR 2011

18 Defining a Significant Stenosis in an Autologous Radio Cephalic Arteriovenous Fistula for Hemodialysis Seminars in Dialysis. Fahrtash, F et al Volume 24, Issue 2, pages , 25 APR 2011

19 Defining a Significant Stenosis in an Autologous Radio-Cephalic Arteriovenous Fistula for Hemodialysis Farzan Fahrtash,* Lukas Kairaitis, Simon Gruenewald, Tim Spicer, Hannah Sidrak, John Fletcher,* Richard Allen, and Jan Swinnen* *Vascular Surgery, Westmead Hospital, Department of Renal Medicine, Westmead Hospital, Departmentof Nuclear Medicine and Ultrasound, Westmead Hospital, Department of Renal Medicine, Liverpool Hospital, and Department of Transplant Medicine, University of Sydney, Sydney, Australia Seminars in dialysis march 2011

20 RC-fistel, underarmen 93 i studiegrupp, 77 i kontrollgrupp Vendiameter 2,7 mm (90%sens, 80% spec för att skilja en fungerande från en ickefungerande fistel)

21 Duplex classification of dialysis access stenosis. Scan Interpretation Recorded Velocity Spectra Color Doppler Imaging Normal <50% DR stenosis Arterial anastomosis >200 cm/s Mid-conduit PSV >150 cm/s PSV anastomosis cm/s PSV conduit lesion <400 cm/s Local PSV ratio <2 Mid-graft PSV cm/s No graft stenosis imaged Patent venous outflow Decrease in lumen diameter >50% DR stenosis PSV anastomosis >400 cm/s Focal lumen reduction PSV conduit lesion >400 cm/s Local PSV ratio >2.5 Mid-graft PSV <100 cm/s Diameter <2 3 mm Occlusion No Doppler signal in conduit Conduit occluded Bandyk, F. Interpretation of duplex ultrasound dialysis access testing. Seminars in vascular surgery 26(2013)

22 Stenosgradering Venstenos hastighetskvot >2-2,5 maxhastighet >4m/s Diameter <2,7 mm Anastomoser->4 m/s Nativ artär-hast.kvot>2-2,5 (>50%stenos) Bandyk, D. Interpretation of duplex ultrasound dialysis access testing. Seminars in vascular surgery 26(2013)

23 Proximal stenos Ofta svåråtkomlig för direkt bedömning Smalt lumen, hastighetsökning Dilaterade vener distalt Kollateraler Nedsatt andningsvariation Flebografi eller CT

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38 Subclaviastenos

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40 Stenoser Ultraljud-detekterar stenos men predikterar ej trombos När är det dags för intervention? PTA eller öppen revision? Efter PTA risk för restenos Öppen revision? Ange stenosens läge i relation till yttre anatomiskt landmärke, t ex ärr

41 Öppen revision Interposition Proximalisering Patch

42 Vengren

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45 Partiellt trombotiserad fistelven

46 Trombos, ocklusion

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50 Arteriellt aneurysm vid anastomos

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53 Pseudoaneurysm syntetgraft

54 Pseudoaneurysm syntetgraft

55 Infektion

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57 Steal Etiologi Ateroskleros proximalt/distalt om fisteln Flöden > ml/min Riskfaktorer Kvinnligt kön Ålder>60 Diabetes

58 Steal-fynd Kliniskt Digital ischemi Kardiell belastning Ultraljud Ev reverserat flöde distalt om fisteln (med normalisering vid graftkompression) Stora volymsflöden-små volymsflöden

59 Steal Figure 2. An upstream arterial stenosis leads to mean arterial pressures (MAP) that are lower (e.g. 60%) compared to values observed in its distal portions (80%) due to open collaterals. The presence of an arteriovenous anastomosis may add to loco-regional hypotension. Under these circumstances, steal (reversal of flow) may be observed in a run-off vessel. Numbers are percentages of MAP, 100 reflects left ventricular MAP. European Journal of Vascular and Endovascular Surgery Scheltinga, MR, Volume 43, Issue 2, February 2012, Pages

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68 Felkällor Felmätning-doppler och diametrar Felbedömning-vinkelkorrektionssvårigheter Förbiseende av stenoser -centrala stenoser svåråtkomliga -fistelområdet svårframställt om många kärl och stora flöden