Simplified Measurement of Intra-Access Pressure

Besarab, Anatole; Al-Saghir, F.; Alnabhan, Nabhan; Lubkowski, T.; Frinak, Stanley

doi:10.1097/00002480-199609000-00074

Cited by 55 publications

(59 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The model predicts that at 50% stenosis, the mean VP/MAP is 0.49 ( Figure 6). This result closely agrees with the observation that 0.50 is the optimum threshold for detecting 50% stenosis in patients with grafts (33).…”

Section: Discussionsupporting

confidence: 92%

See 1 more Smart Citation

Mathematical Model Demonstrates Influence of Luminal Diameters on Venous Pressure Surveillance

White

Jones

Ram

et al. 2007

Clinical Journal of the American Society of Nephrology

View full text Add to dashboard Cite

Background: The reliability of dialysis venous pressure (VP) in detecting stenosis is controversial. A mathematical model may help to resolve the controversy by providing insight into the factors that influence static VP.Design, setting, participants, and measurements: This study used inflow artery and outflow vein luminal diameters from duplex ultrasound studies of 94 patients. These diameters were applied to a mathematical model, and how they affect the relation among VP, mean arterial pressure (MAP), blood flow, and stenosis was determined. Whether VP/MAP is a valid adjustment for the influence of MAP on VP, and whether the standard VP/MAP referral threshold of 0.50 is valid, were also determined.Results: It was found that there is an approximate one-to-one relation between MAP and VP, so VP/MAP is a valid adjustment. Also, the 0.50 threshold successfully identifies most grafts with stenosis of 65% or more. However, the ratio of artery/vein diameters varied widely between patients, and the ratio independently influences VP/MAP. When the inflow artery is relatively narrow, the VP/MAP increase is delayed followed by a more rapid increase as critical stenosis is reached.Conclusions: VP/MAP is a valid adjustment for the influence of MAP on VP, and the standard VP/MAP threshold of 0.50 warns of the transition to critical stenosis. However, relatively narrow arteries cause a delay followed by a rapid increase in VP/MAP that may not be detected before thrombosis unless measurements are very frequent. Clinical trials that emphasize trend analysis with frequent measurements are needed to evaluate the efficacy of VP surveillance.

show abstract

Section: Discussionsupporting

confidence: 92%

“…Besarab et al (20,33) found that a high VP/MAP is associated with low Q, whereas Spergel et al (22) found no correlation between VP/MAP and Q (Figure 9). Thus, we used the model to examine the relation between these variables.…”

Section: Discussionmentioning

confidence: 97%

Mathematical Model Demonstrates Influence of Luminal Diameters on Venous Pressure Surveillance

White

Jones

Ram

et al. 2007

Clinical Journal of the American Society of Nephrology

View full text Add to dashboard Cite

show abstract

“…The concept of prospective monitoring with elective intervention to maintain patency of AV access has been carried out in multiple clinical studies (Schwab, 1999;Kanterman, 1995;Vaiji, 1991;Safa, 1995;Sands, 1995;Turmel-Rodrigues, 1993;Besarab, 1998). This study confirms previous data that preemptive angioplasty of the AV access has benefits on decreasing the incidence of thrombectomies, access failure and missed dialysis sessions (Schwab, 1995;Safa, 1995).…”

Section: Discussionsupporting

confidence: 72%

Decreased Incidence of Clotted AV Access in Hemodialysis Patients after the Implementation of Follow up Program

Magbri¹,

McCartney²,

El-Magbri³

et al. 2016

GJHS

View full text Add to dashboard Cite

Background and 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...

show abstract

“…In general, one would expect to see an impact of fistula flow on cardiac output and left ventricular dimensions. In fact, this would probably apply to a population with more heterogeneous flow characteristics, as found by others (5,7,9,12,20). Another explanation could be the difficulty of achieving adequate measurements of the flow, since flow measurements can only be made in locations with laminar flow and free from disturbance.…”

Section: Discussionmentioning

confidence: 93%

Fistula Diameter Correlates with Echocardiographic Characteristics in Stable Hemodialysis Patients

Hadimeri

Smedby

Fransson

et al. 2015

Nephrology @ Point of Care

View full text Add to dashboard Cite

Aims and background Left ventricular hypertrophy (LVH) is a common finding in hemodialysis patients. The aim of the present study was to investigate if the diameter of the distal radiocephalic fistula could influence left ventricular variables in stable hemodialysis patients. Methods Nineteen patients were investigated. Measurements of the diameter of the arteriovenous (AV) fistula were performed in 4 different locations. The patients were investigated using M-mode recordings and measurements in the 2D image. Doppler ultrasound was also performed. Transonic measurements were performed after ultrasound investigation. Results Fistula mean and maximal diameter correlated with left ventricular characteristics. Fistula flow correlated neither with the left ventricular characteristics nor with fistula diameters. Conclusions The maximal diameter of the distal AV fistula seems to be a sensitive marker of LVH in stable hemodialysis patients.

show abstract

Simplified Measurement of Intra-Access Pressure

Cited by 55 publications

References 0 publications

Mathematical Model Demonstrates Influence of Luminal Diameters on Venous Pressure Surveillance

Mathematical Model Demonstrates Influence of Luminal Diameters on Venous Pressure Surveillance

Decreased Incidence of Clotted AV Access in Hemodialysis Patients after the Implementation of Follow up Program

Fistula Diameter Correlates with Echocardiographic Characteristics in Stable Hemodialysis Patients

Contact Info

Product

Resources

About