**5.8 AVG thrombolysis**

Graft thrombosis occurs in one-third of all AVG per year, and of those that thrombose, 60% have more than two episodes per year. Ninety percent of all AVG thrombosis are associated with a stenotic lesion, most commonly in the venous anastomosis, but can occur in any location, in 36% of the cases in more than one site.

In our VAC, AVG thrombosis is primarily referred to interventional nephrology for endovascular thrombectomy, combining pharmaco-mechanical thrombolysis with a multiperforated catheter occluded at its tip, allowing high-pressure lateral injection of heparinized saline to dislodge wall adherent clots, followed by angioplasty with a 8 mm balloon of all stenotic lesions and finally embolectomy of the arterial anastomosis with a 4 French Fogarty catheter, to remove a more adherent, residual, fibrin "white" clot. Alternatively, some of us may use a mechanical device, the Arrow-Trerotola©, that combines clot fragmentation and aspiration, adding quite a substantial extra cost, without improving outcomes.

**195**

surgery.

**Figure 4.**

*angiogram result.*

**6. Endovascular intervention outcomes**

to the VAC <0.8/patient years.

*Early Detection and Endovascular Intervention to Correct Dialysis Vascular Access Malfunction*

The procedure should not be performed if the AVG is suspected to be infected or a graft rupture is detected. At the end of the procedure, we must check AVG flow, the presence of residual clot inside the VA, and the most dreadful complication, symptomatic hand ischemia due to distal arterial embolization, which must be resolved with embolectomy in the angiographic suite or urgently referred to

*(a) Stop flow at right BCT. (b) Placement of a stent. (c) Angiogram after 12 mm PTA balloon. (d) Final* 

The quality indicators achieved in our VAC include: (a) creation of a nAVF as first access in 80% of all patients and in 60% of subsequent accesses, (b) less than 40% primary failure of nAVF at 3 months, (c) less than 55% secondary failure of nAVF at 12 months, (d) less than 30% primary failure of AVGs at 3 months, (e) percent of functioning AVG post-thrombolysis >75% at 7 days and >50% at 3 months, and (f) no VA infections 15 days post-intervention. Regarding VA, the dialysis unit quality indicators are (a) percent of prevalent patients with nAVF >65%, (b) percent of patients with long-term tunneled catheters <20%, and (c) referral's rate

*DOI: http://dx.doi.org/10.5772/intechopen.92631*

*Early Detection and Endovascular Intervention to Correct Dialysis Vascular Access Malfunction DOI: http://dx.doi.org/10.5772/intechopen.92631*

**Figure 4.**

*Cardiac Diseases - Novel Aspects of Cardiac Risk, Cardiorenal Pathology and Cardiac Interventions*

recurrences. More trials are needed to find out if this more expensive material can

Several challenges must be faced by resistant or recurrent stenosis throughout the access circuit in terms of providing optimal hemodialysis treatment. Those stenoses can be successfully treated by endovascular stent placement, although it

Indeed, bare metal stents and covered stents have emerged as a potential additional therapeutic intervention in vascular access dysfunction. However, results are not encouraging. For example, bare stents are seldom used due to a high incidence

There are three mostly accepted indications for stent deployment: (i) a stenotic lesion that recurs within a 3-month period after initially successful balloon angioplasty in a patient with *exhausted VA sites*, (ii) a stenotic lesion with high elastic recoil (usually in central veins), and (iii) rupture of an outflow vein after balloon angioplasty that cannot be handled using more conventional actions (balloon tamponade). Other special conditions where a stent implantation should be considered include (i) venous

really increase the patency of venous lesions.

usually requires multiple procedures to maintain patency.

of in-stent stenosis, and covered stents also have problems.

stents (struts) can result from repetitive cannulation.

quite a substantial extra cost, without improving outcomes.

outflow stenosis, (ii) pseudo-aneurysms, and (iii) cephalic arch stenosis.

We must take special care not to occlude important collateral veins with implanted stent, namely, the homolateral internal jugular vein, always required for

There are several reported complications associated with stent placement, such as stent migration, or stent fracture, which is usually seen on control angiograms. Infection is also a significant complication with potentially tragic outcomes. It should be noted that the combination of the immune-compromised status of patients with ESRD and repetitive cannulations for dialysis treatments is likely factors leading to infection. One unique complication is stent struts protrusion, which results from placing stents in cannulation sites [62]. Damage of the metal part of the

The high cost of stents has to be taken into account, raising the question whether the benefits obtained by placing stents at stenotic lesions outweigh the costs associated with such treatment [9]. One should reflect if the option of creating a secondary AVF should be considered as an alternative treatment for placing a stent (**Figure 4**).

Graft thrombosis occurs in one-third of all AVG per year, and of those that thrombose, 60% have more than two episodes per year. Ninety percent of all AVG thrombosis are associated with a stenotic lesion, most commonly in the venous anastomosis, but can occur in any location, in 36% of the cases in more

In our VAC, AVG thrombosis is primarily referred to interventional nephrology for endovascular thrombectomy, combining pharmaco-mechanical thrombolysis with a multiperforated catheter occluded at its tip, allowing high-pressure lateral injection of heparinized saline to dislodge wall adherent clots, followed by angioplasty with a 8 mm balloon of all stenotic lesions and finally embolectomy of the arterial anastomosis with a 4 French Fogarty catheter, to remove a more adherent, residual, fibrin "white" clot. Alternatively, some of us may use a mechanical device, the Arrow-Trerotola©, that combines clot fragmentation and aspiration, adding

**5.7 Stent placement**

future central vein catheters.

**5.8 AVG thrombolysis**

than one site.

**194**

*(a) Stop flow at right BCT. (b) Placement of a stent. (c) Angiogram after 12 mm PTA balloon. (d) Final angiogram result.*

The procedure should not be performed if the AVG is suspected to be infected or a graft rupture is detected. At the end of the procedure, we must check AVG flow, the presence of residual clot inside the VA, and the most dreadful complication, symptomatic hand ischemia due to distal arterial embolization, which must be resolved with embolectomy in the angiographic suite or urgently referred to surgery.
