Editorial American
Journal of
Nephrology
Am J Nephrol 2015;41:418–419 DOI: 10.1159/000437153
Published online: July 10, 2015
Can We Improve Dialysis Arteriovenous Graft Survival? Dimitrios Karnabatidis University of Patras Medical School, Department of Radiology, Patras, Greece
© 2015 S. Karger AG, Basel 0250–8095/15/0415–0418$39.50/0 E-Mail [email protected] www.karger.com/ajn
should be taken into consideration prior to applying this strategy in every day clinical practice, as the study presents significant limitations. First of all, although the authors included a substantial number of AVGs (340 cases) and all procedures were performed in an experienced center, this was a retrospective, single-center study. Furthermore, the authors performed pre-emptive angioplasty in patients in whom DUS-defined significant stenosis was detected, driven by their previous publication of a randomized controlled trial (RCT) indicating that pre-emptive angioplasty improved AVG patency [4]. This posed an important bias, as it was not possible to know whether preemptive angioplasty positively or negatively affected survival, by inducing a more aggressive hyperplastic process. The discussion about surveillance and preemptive angioplasty has interested investigators for many years, but until today, although DUS surveillance has been proven to be effective in detecting stenosis within AVGs, the benefit from pre-emptive angioplasty in prolonging access survival has been disputed by 5 RCTs [5]. As a result, currently available evidence indicates that surveillance-guided pre-emptive angioplasty may decrease thrombosis rate, but does not increase the rate of overall AVG survival [6]. Failure of pre-emptive angioplasty to improve access survival could be attributed, among other factors, to its poor mid-term benefit, as Prof. Dimitrios Karnabatidis University of Patras Medical School Department of Radiology, Markora 15 GR–26442 Patras (Greece) E-Mail karnaby @ upatras.gr
Downloaded by: Emory University 198.143.47.65 - 1/26/2016 7:28:02 PM
Failing dialysis access accounts for approximately 20% of end-stage renal disease patient admission in the US and remains a major source of morbidity and mortality [1]. Although native arteriovenous fistula is the vascular access of choice (fistula first), the use of synthetic arteriovenous grafts (AVGs) remain a valid and frequent solution for dialysis worldwide. AVG failure is mainly caused by thrombosis which most of the time is attributed to significant stenosis within the arteriovenous circuit. Stenosis is also the main cause of AVG dysfunction leading to inadequate dialysis [2]. In their article ‘Arteriovenous grafts: early ultrasonography tells their fortune’, Kudlicka et al. [3] investigated the efficacy of early surveillance using Doppler ultrasonography (DUS), following AVG creation, to aid in identifying predictors related to decreased vascular access survival. Interestingly, the authors correlated early significant stenosis detected by DUS with a substantial higher risk of access loss (hazards ratio 14.73; 95% CI 5.10– 42.58). Moreover, the combination of DUS risk factors, such as initial AVG flow volume
Journal of
Nephrology
Am J Nephrol 2015;41:418–419 DOI: 10.1159/000437153
Published online: July 10, 2015
Can We Improve Dialysis Arteriovenous Graft Survival? Dimitrios Karnabatidis University of Patras Medical School, Department of Radiology, Patras, Greece
© 2015 S. Karger AG, Basel 0250–8095/15/0415–0418$39.50/0 E-Mail [email protected] www.karger.com/ajn
should be taken into consideration prior to applying this strategy in every day clinical practice, as the study presents significant limitations. First of all, although the authors included a substantial number of AVGs (340 cases) and all procedures were performed in an experienced center, this was a retrospective, single-center study. Furthermore, the authors performed pre-emptive angioplasty in patients in whom DUS-defined significant stenosis was detected, driven by their previous publication of a randomized controlled trial (RCT) indicating that pre-emptive angioplasty improved AVG patency [4]. This posed an important bias, as it was not possible to know whether preemptive angioplasty positively or negatively affected survival, by inducing a more aggressive hyperplastic process. The discussion about surveillance and preemptive angioplasty has interested investigators for many years, but until today, although DUS surveillance has been proven to be effective in detecting stenosis within AVGs, the benefit from pre-emptive angioplasty in prolonging access survival has been disputed by 5 RCTs [5]. As a result, currently available evidence indicates that surveillance-guided pre-emptive angioplasty may decrease thrombosis rate, but does not increase the rate of overall AVG survival [6]. Failure of pre-emptive angioplasty to improve access survival could be attributed, among other factors, to its poor mid-term benefit, as Prof. Dimitrios Karnabatidis University of Patras Medical School Department of Radiology, Markora 15 GR–26442 Patras (Greece) E-Mail karnaby @ upatras.gr
Downloaded by: Emory University 198.143.47.65 - 1/26/2016 7:28:02 PM
Failing dialysis access accounts for approximately 20% of end-stage renal disease patient admission in the US and remains a major source of morbidity and mortality [1]. Although native arteriovenous fistula is the vascular access of choice (fistula first), the use of synthetic arteriovenous grafts (AVGs) remain a valid and frequent solution for dialysis worldwide. AVG failure is mainly caused by thrombosis which most of the time is attributed to significant stenosis within the arteriovenous circuit. Stenosis is also the main cause of AVG dysfunction leading to inadequate dialysis [2]. In their article ‘Arteriovenous grafts: early ultrasonography tells their fortune’, Kudlicka et al. [3] investigated the efficacy of early surveillance using Doppler ultrasonography (DUS), following AVG creation, to aid in identifying predictors related to decreased vascular access survival. Interestingly, the authors correlated early significant stenosis detected by DUS with a substantial higher risk of access loss (hazards ratio 14.73; 95% CI 5.10– 42.58). Moreover, the combination of DUS risk factors, such as initial AVG flow volume
