Decreased Incidence of Clotted AV Access in Hemodialysis Patients after the Implementation of Follow up Program.
BACKGROUND & OBJECTIVES
Access monitoring and pre-emptive angioplasty is known to decrease the incidence of AVF/AVG thrombosis. The effect on increase the longevity and functionality of Arterial-Venous access (AV access) in end-stage renal disease (ESRD) patients is not settled. Thrombosis is the leading cause of vascular access complications and is almost always associated with the presence of stenosis. Percutaneous transluminal angioplasty (PTA) is an accepted treatment of stenotic lesions in AV access (NKF 2001). The purpose of this study is to assess the effect of follow up of ESRD patients in the dialysis access center with preemptive angioplasty on access thrombosis.


DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
This is a single center observational interventional study extended over 9 years (Jan 1, 2006 to Dec 31, 2014) at the Dialysis Access Center of Pittsburgh, PA. The study is divided into 2 periods, period A (from Jan 2006 to December 2009), where follow up program was not in place. Period B extends from (January 1, 2011 to December 31, 2014). In this period, a follow up of patients with preemptive angioplasty of AV access has been implemented. We decided not to include 2010 as the program is implemented at the end of that year and including this year might skewed the data. All patients with ESRD on HD are seen in the Dialysis access center of Pittsburgh for access monitoring and interventional PTA if deemed necessary. Patients' data were abstracted from the electronic medical records. The study is approved by the IRB of Lifeline corp.


RESULTS
During period A; a total of 4139 encounters with a mean of 1034, (1653 angioplasties with mean of 413/year, 375 angiogram, mean 94/year, and 303 thrombectomies of AVF/AVG with a mean 76/year) were carried out. Thrombectomies constituted (7.3%) of the total procedures performed.Table 1 showed the mean distributions of AVG, AVF, and tunneled dialysis catheters (TDC) frequencies compared to national average in periods A & B.In period B, a total of 6229 encounters with mean of 1557 encounter/year were performed, (3202 angioplasties, mean 801/year, 950 angiograms, mean 238/year, and 196 thrombectomies, mean 42/year) were done. Thrombectomies were decreased almost 2 folds in this period (7.3% to 3.15%).The percentage of patients being dialyzed via TDC decreased in period B from 31.895% to 17.38%. The numbers of thrombectomies have also been decreased from average 76 to 42 /year (7.3% to 3.15%).After implementing the program, as illustrated in period B, compared to the national average, the frequency of thrombectomies (3.15% vs. 9.6%) and TDC use (17.38% vs. 18%), have showed significant improvement. Meanwhile, the number of PTA has doubled from an average of (413 to 801/year) between the 2 periods. Our fistula rate has gone up from 48.7% to 66.2% between the 2 periods. Mild increase of the AVG use (12.07% to 18.07%) has also been observed. However, the use of TDC has decreased from (31.42% to 17.38%). These results are consistent with the motto of (fistula first and catheter last). The growth of PTA may explain the positive impact of this program on the number of thrombectomies as well as maintenance of access functionality in ESRD patients. The rate of PTA has gone up from (39.85% to 51.25%). This trade off may be acceptable if access patency and functionality have to be maintained. It is not clear whether the follow up program with preemptive angioplasty would have a positive effect on the access expenditure and access longevity in this group of patients.


CONCLUSION
Follow up of ESRD patients in the dialysis access center and preemptive angioplasty if need be is an acceptable means to decrease the number of failed accesses, thrombectomies, as well as the use of TDC in ESRD patients.