Scoring Balloon and High Pressure Balloon in the Treatment of Arteriovenous Graft Stenosis

Target Lesion Primary Patency (TLPP) at 12 months post-procedure

TLPP is terminated by postoperative target lesion failure (TLF) (including the 5 mm range before and after the target lesion) or target lesion-related vascular access thrombosis. TLF is defined as the presence of at least one clinical indicator (defined according to the NKF-K/DOQI guidelines) caused by target lesion stenosis ( ≥50% stenosis of the target lesion assessed by contrast angiography or ultrasound), including physical examination abnormalities or dialysis abnormalities. Target lesion-related vascular access thrombosis is limited to: after the thrombus is removed during AVG thrombus treatment and before balloon dilatation, it is confirmed by ultrasound/DSA that the original target lesion has a stenosis ≥ 50%, or when the balloon is expanded with low pressure (\<6 atm) during intraluminal treatment, obvious balloon residual waisting can be seen at the target lesion; simple mural thrombus at the puncture point or other parts of the graft needs to be ruled out.

Time frame: 12 months

Access Circuit Primary Patency (ACPP) at 6 and 12 months post-procedure

ACPP is terminated when stenosis or thrombus causing abnormal clinical indicators occurs in any part of the AVG after surgery (inflow artery, entire graft, and outflow vein, including central vein). (Definition according to NKF- K/DOQI guidelines), including physical examination abnormalities or dialysis abnormalities. Physical examination abnormalities include: open collateral veins, ipsilateral limb edema, changes in pulse characteristics, abnormal tremors, abnormal murmurs, etc.; Dialysis abnormalities include: increased venous pressure, new puncture difficulties, aspiration of thrombi, inability to reach target dialysis blood flow, prolonged haemostasis time after needle removal for 3 consecutive times, unexplained decrease in dialysis dose Kt/V (\>0.2 units), decrease in brachial artery blood flow (brachial artery blood flow \<650ml/min or decreased by 20% compared with the previous follow-up visit), etc.

Time frame: 6, 12 months post-procedure

Access Circuit Secondary Patency (ACSP) 6 and 12 months after surgery

ACSP terminates when the AVG is abandoned due to various reasons after surgery, during which multiple interventions can be performed to maintain the patency of the entire pathway.

Time frame: 6, 12 months post-procedure

Acute Lumen Gain

Immediately after dilation, DSA uses two different angles (≥45°) for angiography (a unified x-ray ruler will be provided as the reference object to reduce measurement errors) Calculation formula: minimum lumen diameter of the target lesion immediately after dilation - minimum lumen diameter of the target lesion before procedure.

Time frame: During the procedure

Technical Success

Residual stenosis of the target lesion after surgery is ≤30%, and no serious adverse events related to the investigational device occurred during the perioperative period.

Time frame: 0-5 days post-procedure

Clinical Success

Complete at least one successful hemodialysis session after surgery

Time frame: 0-5 days post-procedure