The Art of Angioplasty

Transcription

1 The Art of Angioplasty Achieving and Defining Success Thomas M. Vesely, MD Saint Louis, Missouri

2 Dr. Vesely is a consultant for: W.L. Gore & Associates Lutonix

3 Imaging the Vascular Access Circuit

4 A well performed fistulogram is the foundation for all percutaneous interventions Scott Trerotola, M.D. Thorough evaluation of the entire vascular access circuit including fistula/graft, peripheral veins, central veins and arterial anastomosis

5 Patient s upper torso positioned on fluoroscopy table T but the lower patient body on remains the angiography on stretcher table

6 Image intensifier can easily track from chest to hand

7 Drape is positioned along angio table and over patient s chest

8 Provides easy movement of guidewires and catheters

9 Fluoroscopic Imaging Techniques

10 Fluoroscopic spot film of left upper arm

11 Soft filter Hard filter Hard filter Soft filter

12 Hard filters aligned with soft filters

13 Positioning tip of angiographic catheter axillary vein unopacified vein tip of catheter Poor positioning of catheter tip will increase radiation dose and amount of x-ray contrast given to patient

14 catheter tip left elbow catheter tip Catheter tip should be at edge of image in order to opacify long length of vein (or artery)

15 Contrast Density You can t see what you can t see Tom Vesely, MD

16 Full strength x-ray contrast Diluted contrast (50% contrast / 50% saline)

17 What would you do to get a better look at this stenosis?

18 II II Rotation of the image intensifier (II) to obtain orthogonal views of the lesion

19 With arm rotated there is clear visualization of stenosis

20 Forearm in A-P position Forearm rotated 90-degrees under drape Note change in position of angiographic catheter Manual rotation of the patient s arm to obtain orthogonal views of the lesion

21 Forearm supination Forearm pronation

22 Forearm supination Forearm pronation

23 Delayed Imaging

24 direction of blood flow upper right basilic vein PTFE hemodialysis graft in right upper arm venous anastomosis Notice dilute concentration of x-ray contrast

25 Delayed image shows persistent opacification of pseudoaneurysms

26 Occlusion of right central veins

27 Delayed images show that left brachiocephalic vein and SVC are patent

28 Angioplasty 7mm graft basilic vein Venous anastomotic stenosis of a right upper arm PTFE graft

29 Angioplasty-induced venous rupture Delayed image verifies acute pseudoaneurysm

30 pre-thrombectomy post-thrombectomy Vein size is dependent upon blood flow

31 Pre-thrombectomy Post-thrombectomy No angioplasty

32 Pre-thrombectomy No angioplasty Post-thrombectomy

33 The Art of Angioplasty Achieving and Defining Success

34 Standards & Guidelines for Hemodialysis Access Procedures Surgery Radiology Nephrology

35 Definitions of Success Anatomic Success: Less than 30% residual stenosis Hemodynamic : Success Restoration of hemodynamic parameter No criteria defined Clinical Success: Ability to undergo one hemodialysis treatment

36 graft basilic vein What is the degree of stenosis?

37 Problems: measurement techniques selection of reference vessel selection of best view eccentric lesions

38 Anatomic Success vs. Long-term Patency Clark T et al. JVIR 2002; 13: patients with fistulas underwent endovascular interventions 17 anatomic failures with >30% residual stenosis No difference in the long-term patency compared to patients with all lesions <30% residual stenosis

39 Mathematical model: forearm loop graft diameter: 6 mm, length 40 cm, stenosis length 2.0 cm, Blood flow ml/min Percent Stenosis

40 The use of < 30% residual stenosis as a derminant of success is not supported by hemodynamic or physiologic studies. Quantitative measurement of hemodynamic parameters should provide a better assessment of vascular access performance and outcomes. Tom Vesely, M.D.

41 Hemodynamic Success Pullback Pressure Measurements 9mmHg - reduce gradient to < 5 mmhg - no consensus on criteria 22mmHg 22 mmhg - 9 mmhg = 13 mmhg Funaki B AJR 2002; 178:

42 Intraprocedural Measurement of Blood Flow

43 J Vasc Intervent Radiol 2004; 15:

44 Pre-PTA degree of stenosis Post-PTA degree of stenosis Δ Degree of stenosis Length of stenosis Access blood flow Δ Access blood flow

45 Conclusions Attention to imaging techniques improve one s ability to identify and characterize stenoses Angiography is a poor method to evaluate the effectiveness of an angioplasty procedure Current definitions of angioplasty success are based upon outdated concepts and should be rewritten

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