Utility of Static Pressure Ratio Recording during Angioplasty of Arteriovenous Graft Stenosis

Abstract

Intra-access static pressure ratio (SPR) (intra-access pressure/mean arterial pressure) can be measured during angioplasty (PTA) to assess the functional importance of an arteriovenous graft (AVG) stenosis. We used SPR in 70 patients with AVGs who underwent 98 angioplasty procedures. SPR was measured during angioplasty by placing a catheter tip at mid-access. Inflow stenosis (IF) = stenosis proximal to the tip of the catheter. Outflow stenosis (OF) = stenosis distal to the tip of the catheter up to the superior vena cava-atrial junction. Post PTA, access flow (Qa) was assessed within 2 weeks. Complete data sets for both SPR and Qa were available in 83 procedures. Using a normal SPR ratio of 0.3-0.4 at mid-graft, three patterns of SPR were noted. In 63 of 83 (76%) cases SPR was elevated prior to PTA (0.71 +/- 0.13 SD). PTA reduced SPR toward normal range (0.44 +/- 0.12) in 53 cases (84%). In the remaining 10 (16%), SPR decreased to a low value (0.22 +/- 0.03) and normalized (0.40 +/- .0.11) only after PTA of a coexisting inflow stenosis. In 12 of 83 (14%) procedures, the initial SPR was low (0.18 +/- 0.04) and increased toward normal (0.3 +/- 0.08) following IF stenosis PTA in seven (58%) cases. For the remaining five (42%) cases SPR increased to a high value (0.70 +/- 0.21) and decreased toward normal range (0.33 +/- 0.07) only after OF stenosis angioplasty. In 8 of 83 (10%) procedures, initial SPR was normal (0.33 +/- 0.02). Angiography revealed coexisting IF and OF stenoses. SPR remained within the normal range after PTA of these lesions (0.33 +/- 0.02). Qa increased significantly in 74 of 83 (89%) procedures (before = 572 +/- 201, after = 1109 +/- 368 ml/min; p < 0.001). SPR measurements can assist in hemodynamic assessment of an AVG during angioplasty procedure.

Cardiovascular Implantable Electronic Device Leads in CKD and ESRD Patients: Review and Recommendations for Practice

“…These patients are prone to developing clinically significant venous hypertension due to the high rate of venous blood return. The mean blood flow in mature fistulae ranges from 780 to 1204 ml/min (25,26) and in grafts 1109 ml/min (27). In some cases, vascular access flow rates exceed 2000 ml/minute (28).…”

Mathematical Model Demonstrates Influence of Luminal Diameters on Venous Pressure Surveillance

“…Finally, angioplasty treatment of outflow stenosis causes an increase in Q combined with a decrease in VP (35). This important observation also suggests that VP measurements during angioplasty procedures may help to confirm successful treatment of hemodynamically significant stenosis.…”

Carbon dioxide CT angiography during endovascular treatment of bilateral common iliac disease with angio‐CT utilisation

“…Finally, the uses of pressure measurement to determine if a gradient was present in the setting of vascular stenosis has been a technique used within the field of Interventional radiology for a long time. It has been demonstrated that catheter directed pressure measurements and determination of a pressure gradient can determine the significance of a stenosis with relative ease and at minimal cost . This provides instantaneous diagnostic information about the stenosis in question allowing prompt treatment to occur .…”

“…It has been demonstrated that catheter directed pressure measurements and determination of a pressure gradient can determine the significance of a stenosis with relative ease and at minimal cost. 9 This provides instantaneous diagnostic information about the stenosis in question allowing prompt treatment to occur. 9 The case presented unfortunately, the ability to perform such measurements could not occur due to technical issues with measurement equipment however it is recognised that catheter based pressure measurements is a valid alternative in procedures as previously described.…”