**6. Endovascular intervention outcomes**

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 to the VAC <0.8/patient years.

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


**Table 1.**

*Primary patency in our VAC at 30, 90, and 180 days, in line with most literature in the field.*


#### **Table 2.**

*Clinical pearls to take home.*

The technical details of all procedures we perform in our VAC are thoroughly described in a recent textbook [63, 64].

The National Kidney Foundation (KDOQI) guidelines [65] define a successful angioplasty a residual stenosis <30%, with return to acceptable levels of the parameters used to place the indication for angioplasty. Initial success rates using anatomical criteria ranged from 80 to 98%, but in some reports, 20–30% of these patients with anatomical success fail to increase blood flow (residual stenosis, a missed lesion, or elasticity). Primary patency rates are 41–76% at 6 months and 31–45% at 1 year.

Long-term primary patency rates for thrombectomy are not as good as for angioplasty; therefore every effort should be made to prevent thrombosis by the prospective diagnosis and treatment of venous stenosis.

In a thrombosed access, the treatment must be timely to avoid catheters, done as an outpatient, venous stenosis must be detected and corrected, hemodynamic parameters should return to baseline, and patient should be evaluated for a secondary arteriovenous native fistula, created using upper arm veins that have become dilated because of the functioning graft.

In 2019, 139 surgical thrombectomies were performed in 127 patients (69 in nAVF and 70 in AVG). In 49.6%, no new intervention was required, and the average time until a new intervention was 46.7 days. Primary patency at 1 month was 66%, at 3 months 54.4%, and at 6 months 17.5%. In that same period, the angiography suite received 134 patients for 179 procedures (171 in AVGs, 8 with a nAVF), there was immediate success in 159 patients, the average time until a new intervention was 58.1-day, and primary patency at 1 month was 71.6% and at 6 months 42.5%. In our case, Qa average improvement is >50%, and we expect a Kt/V above 1.4.

**197**

**Author details**

Pedro Ponce1,2\* and Ana Mateus2

1 Nephrologist, General ICU of Hospital Cuf, Lisbon, Portugal

\*Address all correspondence to: pedro.ponce@fmc-ag.com

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

2 Vascular Access Centers, NephroCare, Portugal

provided the original work is properly cited.

more a question of know-how, but of know-when.

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

The immediate success rate of thrombolysis should be 85% or greater according to the NKF/KDOQI guidelines and the primary (unassisted) patency goals at

In conclusion, we are still dealing with quite a number of known unknowns. There has been no RCT to elucidate which percentage of lumen compromise should dictate the indication for angioplasty, and most operators choose 50%. Not all stenotic plaques were created equal, and some will never progress, but we cannot guess which ones. We also have no proof that a successful PTA in a graft improves longterm patency rate [14], angiographic criteria to assess the success of angioplasty are not predictive of changes in blood flow, and there is no correlation between changes in blood flow and changes in the percent of stenosis post-PTA [66]. In an era characterized by less is more, under the imperative of being useful for our patients, creating long-term solutions at sustainable costs, we feel a desperate need for robust scientific evidence to support our decision process and the procedures we perform. Just because it can be done, does not mean it should be done, our intervention is no

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

3 months at least 40% (**Tables 1** and **2**).

**7. Conclusion**

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

The immediate success rate of thrombolysis should be 85% or greater according to the NKF/KDOQI guidelines and the primary (unassisted) patency goals at 3 months at least 40% (**Tables 1** and **2**).
