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Sharathkumar A, Hirschl R, Pipe S, Crandell C, Adams B, Lin J. Primary Thromboprophylaxis with Heparins for Arteriovenous Fistula Failure in Pediatric Patients. J Vasc Access 2018. [DOI: 10.1177/112972980700800404] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background To reduce the incidence of early arteriovenous fistula failure (AVF) due to thrombosis in pediatric hemodialysis (HD) patients, a primary thromboprophylaxis (PTP) protocol was initiated at author's institution in June 2005. The goal of this study is to report author's experience with this protocol one year later. Methods and Results 19 AVFs (14 patients, Historical group) and 8 AVFs (7 patients, PTP group) were created prior to and after initiation of PTP respectively. PTP consisted of unfractionated heparin (5–10 units/kg/hr) infusion postoperatively, followed by subcutaneous low molecular weigh heparin (LMWH) until AVF was matured. LMWH dosing was “Prophylactic” (0.5 mg/kg/d, anti-factor Xa levels: peak 0.25–0.5 and trough < 0.3 units/mL) and “Therapeutic” (1 mg/kg/d, anti-factor Xa level: peak 0.5-1 and trough < 0.5 units/mL) based on thrombosis predisposition. In Historical group, 12 AVFs did not receive thromboprophylaxis (No-treatment group), 5 received 81 mg aspirin/day (Aspirin group), and 2 received LMWH. In No-treatment group 10/12 AVFs failed: 9 thromboses and 1 stenosis. In Aspirin group 1/5 AVFs failed due to thrombosis. In PTP group 1/8 AVFs failed due to stenosis; the first 2 AVFs developed hematoma prompting a reduction in LMWH dose and monitoring trough anti-factor Xa levels, one AVF required thrombectomy after LMWH was transiently held. The incidence of thrombosis was less in PTP group (12.5%) when comparing to No-treatment group (83%) (p < 0.05). Conclusion PTP is a feasible option to prevent early thrombosis at AVF. Close clinical and laboratory monitoring including trough anti-factor Xa levels is required to adjust optimum anticoagulation. Larger studies are needed to clarify safety and efficacy of our PTP protocol.
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Affiliation(s)
- A. Sharathkumar
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI - USA
| | - R. Hirschl
- Department of Pediatric Surgery, University of Michigan, Ann Arbor, MI - USA
| | - S. Pipe
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI - USA
| | - C. Crandell
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI - USA
| | - B. Adams
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI - USA
| | - J.J. Lin
- Department of Pediatrics, East Carolina University, Greenville, NC - USA
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Lok CE, Allon M, Donnelly S, Dorval M, Hemmelgarn B, Moist L, Oliver MJ, Tonelli M, Stanley K. Design of the fish oil inhibition of stenosis in hemodialysis grafts (FISH) study. Clin Trials 2016; 4:357-67. [PMID: 17848497 DOI: 10.1177/1740774507081218] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Arteriovenous grafts (AVG) are the predominant form of permanent vascular access used among hemodialysis (HD) patients in North America but suffer from high intervention and complication rates associated with vascular stenosis. The fish oil inhibition of stenosis in hemodialysis grafts (FISH) study evaluates the efficacy of fish oil in improving HD graft patency.Methods This study is a multi-center, randomized, double blind placebo-controlled clinical trial of 232 chronic HD patients who require a new graft access. Participants are randomized to fish oil versus placebo post-operatively. The primary endpoint is the proportion of AVG with loss of native patency within 12 months of creation. Secondary endpoints are aimed to determine the effect of fish oil on factors that may promote stenosis and thrombosis. Cumulative patency rates, survival analysis, and analysis of inflammatory markers and adverse events will provide a better understanding of the potential effect of fish oil on a patient's vascular access and cardiovascular system. The FISH study is registered at current controlled trials (www.controlled-trials.com) ISRCTN: 15838383.Results Details of the study protocol are described including mechanisms of reducing bias through randomization and double blinding, sample size determination, evaluation of patient adherence, access monitoring, and the safety of using fish oil. The main challenges of designing and implementing this study, including using a natural supplement as an intervention in modern medical practice and recruitment of graft recipients in the `fistula first' environment are discussed. Conclusion This is the first large, multicenter, randomized controlled trial of a natural supplement in preventing HD graft stenosis and thrombosis. Clinical Trials 2007; 4: 357—367. http://ctj.sagepub.com
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Affiliation(s)
- Charmaine E Lok
- Nephrology, University Health Network-Toronto General Hospital, Toronto, Ontario, Canada.
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3
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Birch N, Fillaus J, Florescu MC. The effect of statin therapy on the formation of arteriovenous fistula stenoses and the rate of reoccurrence of previously treated stenoses. Hemodial Int 2012; 17:586-93. [PMID: 23078106 DOI: 10.1111/j.1542-4758.2012.00762.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 08/29/2012] [Indexed: 11/29/2022]
Abstract
Statins reduce inflammation in end-stage renal disease patients and improve endothelial function beyond cholesterol lowering. Despite this, statins do not improve the maturation rate, primary patency rate, and the cumulative survival of arteriovenous fistulas (AVFs). It is unknown if statins decrease the number of stenoses developing in AVFs or prolong the intervals between angioplasties needed to treat recurring stenoses. We conducted a retrospective chart review of our 265 active dialysis patients. The statin group was significantly more likely to be diabetic (64% vs. 43.6%) and treated with aspirin (64% vs. 40%) when compared to those not treated with statins (P=0.04 and 0.01). The mean time to first intervention (primary patency) was 16.5 months in statin users and 15.8 months in the nonstatin group (P=0.49) with standard deviations of ± 18.5 and 16.6 months, respectively. Statin use was not associated with a significant decrease in the number of stenoses diagnosed (P=0.28). The mean time between recurrent stenoses' angioplasties was 8.9 months in statin users and 7.3 months in the nonstatin patients (P=0.25). Aspirin users were more likely to have a decreased primary patency (rate ratio=1.65, P=0.03) compared with nonaspirin users. Patients who were prescribed aspirin developed 1.6 (P 0.01) times more stenoses than those not treated with aspirin. We report for the first time that statin therapy does not decrease the number of stenotic lesions developing in the AVF or prolong the interval between procedures required to treat recurrent stenoses.
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Affiliation(s)
- Nathan Birch
- Internal Medicine Department, Nebraska-Western Iowa V. A. Medical Center, Omaha, Nebraska, USA
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4
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Polkinghorne K. Pharmacological approaches to preventing vascular access failure. Nephrology (Carlton) 2008; 13 Suppl 2:S12-6. [DOI: 10.1111/j.1440-1797.2008.00993.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Yevzlin AS, Conley EL, Sanchez RJ, Young HN, Becker BN. Vascular Access Outcomes and Medication Use: A USRDS Study. Semin Dial 2006; 19:535-9. [PMID: 17150056 DOI: 10.1111/j.1525-139x.2006.00218.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several medications have been proposed to improve hemodialysis (HD) vascular access outcomes based on potentially favorable anticoagulant, antiplatelet, or pleiotropic properties. The purpose of this study was to evaluate the relationship between medication use and vascular access patency in a group of HD patients. We conducted a historical cohort study of the US Renal Data System Dialysis Mortality and Morbidity Wave II study to identify patients with an arteriovenous fistula (AVF), polytetrafluoroethylene (PTFE) graft, or a permanent catheter for vascular access. Cox regression analysis, adjusted for age, gender, race, history of coronary artery disease, peripheral vascular disease, or coronary artery bypass graft, was used to model the hazard ratio (HR) of permanent vascular access failure. Of the 2001 HD patients in the Wave II study, 901 (45%) were included in the analysis. PTFE graft patency was greater for males (HR, 0.73; 95% CI 0.53-1.00, p = 0.05) and for older individuals (HR, 0.99; 95% CI 0.98-1.00, p = 0.02). Treatment with antiplatelet medications, ticlopidine and dipyridamole (HR, 3.54; 95% CI 1.07-11.76; p = 0.04), or aspirin (HR, 2.49; 95% CI 1.31-4.73; p = 0.005) was associated with significantly worse AVF patency. Antiplatelet agents had a significant negative association with access patency in this cohort. In contrast to other published data, it was difficult to identify any beneficial effect of specific medications on access patency.
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MESH Headings
- Adult
- Age Factors
- Aged
- Aged, 80 and over
- Anticoagulants/therapeutic use
- Arteriovenous Shunt, Surgical/adverse effects
- Arteriovenous Shunt, Surgical/instrumentation
- Catheters, Indwelling/adverse effects
- Databases, Factual
- Female
- Graft Occlusion, Vascular/epidemiology
- Graft Occlusion, Vascular/etiology
- Humans
- Kidney Failure, Chronic/epidemiology
- Kidney Failure, Chronic/mortality
- Kidney Failure, Chronic/therapy
- Male
- Middle Aged
- Platelet Aggregation Inhibitors/therapeutic use
- Polytetrafluoroethylene
- Proportional Hazards Models
- Renal Dialysis/adverse effects
- Renal Dialysis/instrumentation
- Retrospective Studies
- Sex Factors
- Survival Analysis
- Treatment Outcome
- United States/epidemiology
- Vascular Patency/drug effects
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Affiliation(s)
- Alexander S Yevzlin
- School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53713, USA.
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Kuji T, Masaki T, Goteti K, Li L, Zhuplatov S, Terry CM, Zhu W, Leypoldt JK, Rathi R, Blumenthal DK, Kern SE, Cheung AK. Efficacy of local dipyridamole therapy in a porcine model of arteriovenous graft stenosis. Kidney Int 2006; 69:2179-85. [PMID: 16672912 DOI: 10.1038/sj.ki.5000383] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Perivascular delivery of antiproliferative drugs has been proposed as an approach to prevent neointimal hyperplasia associated with hemodialysis polytetrafluoroethylene (PTFE) grafts. We examined this approach to deliver dipyridamole in a porcine graft model. PTFE grafts were implanted between the carotid artery and external jugular vein bilaterally in pigs. During the surgery or 1 week post-graft placement, dipyridamole (0.26-52 mg) alone or incorporated in microspheres was mixed with an injectable polymeric gel and applied to the graft-arterial and graft-venous anastomoses on one side, whereas the contralateral control graft received no treatment. Three or four weeks after operation, the grafts and adjacent vessels were explanted en bloc and cross-sections of the anastomoses were examined histologically. The degree of neointimal hyperplasia was quantified by planimetry. In separate experiments, dipyridamole was extracted from the explanted tissues and assayed by spectrofluorometry. The normalized median hyperplasia areas of the treated and control graft-venous anastomoses were 0.45 (25th-75th percentile, 0.30-0.86) and 0.24 (0.21-0.30), respectively (N=7; P=0.08). The median hyperplasia areas of the treated and control graft-arterial anastomoses were 0.12 (0.07-0.39) and 0.11 (0.09-0.13), respectively (N=7; P=0.31). The dipyridamole levels in the vascular walls around the anastomoses were at or above the in vitro inhibitory concentrations for approximately 3 weeks. These results suggest that the local perivascular sustained delivery of dipyridamole, even at high dosages, was ineffective in inhibiting neointimal hyperplasia associated with PTFE grafts in a porcine model.
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Affiliation(s)
- T Kuji
- Department of Medicine, University of Utah, Salt Lake City, Utah 84112, USA
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7
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Dixon BS, Beck GJ, Dember LM, Depner TA, Gassman JJ, Greene T, Himmelfarb J, Hunsicker LG, Kaufman JS, Lawson JH, Meyers CM, Middleton JP, Radeva M, Schwab SJ, Whiting JF, Feldman HI. Design of the Dialysis Access Consortium (DAC) Aggrenox Prevention Of Access Stenosis Trial. Clin Trials 2006; 2:400-12. [PMID: 16317809 DOI: 10.1191/1740774505cn110oa] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Surgically created arteriovenous (AV) grafts are the most common type of hemodialysis vascular access in the United States, but fail frequently due to the development of venous stenosis. The Dialysis Access Consortium (DAC) Aggrenox Prevention of Access Stenosis Trial tests the hypothesis that Aggrenox (containing dipyridamole and aspirin) can prevent stenosis and prolong survival of arteriovenous grafts. METHODS This is a multicenter, randomized, double-blind, placebo-controlled trial that will enroll 1056 subjects over four years with one-half year follow-up. Subjects undergoing placement of a new AV graft for hemodialysis are randomized to treatment with Aggrenox or placebo immediately following access surgery. The primary outcome is primary unassisted patency defined as the time from access placement until thrombosis or an access procedure carried out to maintain or restore patency. The major secondary outcome is cumulative access patency. Monthly access flow monitoring is incorporated in the study design to enhance detection of a hemodynamically significant access stenosis before it leads to thrombosis. RESULTS This paper describes the key issues in trial design, broadly including: 1) ethical issues surrounding the study of a clinical procedure that, although common, is no longer the clinical intervention of choice; 2) acceptable risk (bleeding) from the primary intervention; 3) inclusion of subjects already receiving a portion of the study intervention; 4) inclusion of subjects with incident rather than prevalent qualifying clinical conditions; 5) timing of the study intervention to balance safety and efficacy concerns; and 6) the selection of primary and secondary study endpoints. CONCLUSIONS This is the first, large, multicenter trial evaluating a pharmacologic approach to prevent AV graft stenosis and failure, an important and costly problem in this patient population. Numerous design issues were addressed in implementing the trial and these will form a roadmap for future trials in this area.
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Affiliation(s)
- Bradley S Dixon
- Nephrology Division, Veterans Affairs Medical Center and University of Iowa School of Medicine, Iowa City 52242-1081, USA.
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8
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Obialo CI, Conner AC, Lebon LF. Maintaining patency of tunneled hemodialysis catheters--efficacy of aspirin compared to warfarin. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 2004; 37:172-6. [PMID: 12745728 DOI: 10.1080/00365590310008938] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Tunneled hemodialysis catheters (caths) often fail as a result of luminal obstructive thrombus or formation of a fibrin sheath at the tip. Anecdotal and non-randomized studies have indicated that aspirin (A) and/or warfarin (W) can prolong cath patency. We examined the effect of chronic usage of either A or W on primary cath patency. MATERIAL AND METHODS A prospective cross-sectional monitoring of cath patency was conducted over a 3-year period. Patients were grouped according to their long-term usage of either A (325 mg daily) or W. Patients on neither medication served as a control (C). The end point of the study occurred at cannulation of the patients' arteriovenous fistulae, when there was development of cath-related bacteremia or when there was inability to maintain a blood flow of 250 ml/min. RESULTS Sixty-three patients with a mean age of 57 +/- 15 years completed the study. There were 21 patients in the A group, 11 in the W group and 31 in the C group. Cath survival was 91%, 73% and 29% at 120 days for the A, W and C groups, respectively (A vs C, p < 0.0001; W vs C, p < 0.0001; A vs W, p = NS). The mean durations of cath patency were 114 +/- 18, 111 +/- 17 and 68 +/- 37 days for the A, W and C groups, respectively (A vs C, p < 0.0001; W vs C, p < 0.0001; A vs W, p = NS). Gastrointestinal (GI) bleeding complication rates were 24%, 18% and 0% for the A, W and C groups, respectively (A vs C, p = 0.02; W vs C, p = 0.02; A vs W, p = NS). The relative risk of GI bleeding associated with aspirin was 0.71 [95% confidence interval (CI) 0.11-4.4, p = 0.7] but among elderly aspirin users it was 1.14 (CI 1.0-1.3, p = 0.008). CONCLUSION Both aspirin and warfarin are equally effective at prolonging cath patency but their routine use for failing caths cannot be unequivocally recommended because of the increased risk of GI bleeding. Further prospective and randomized studies are called for.
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Affiliation(s)
- Chamberlain I Obialo
- Department of Medicine, Morehouse School of Medicine, 729 Westview Drive SW, Atlanta, GA 30310, USA.
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9
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Kaufman JS, O'Connor TZ, Zhang JH, Cronin RE, Fiore LD, Ganz MB, Goldfarb DS, Peduzzi PN. Randomized controlled trial of clopidogrel plus aspirin to prevent hemodialysis access graft thrombosis. J Am Soc Nephrol 2003; 14:2313-21. [PMID: 12937308 DOI: 10.1097/01.asn.0000081661.10246.33] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Thrombosis of hemodialysis vascular access grafts represents a major medical and economic burden. Experimental and clinical models suggest a role for antiplatelet agents in the prevention of thrombosis. The study was designed to determine the efficacy of the combination of aspirin and clopidogrel in the prevention of graft thrombosis. The study was a randomized, double-blind trial conducted at 30 hemodialysis units at Veterans Affairs medical centers. Participants undergoing hemodialysis with a polytetrafluoroethylene graft in the arm were randomized to receive either double placebos or aspirin (325 mg) and clopidogrel (75 mg) daily. Participants were to be monitored while receiving study medications for a minimum of 2 yr. The study was stopped after randomization of 200 participants, as recommended by the Data Safety and Monitoring Board because of a significantly increased risk of bleeding among the participants receiving aspirin and clopidogrel therapy. The cumulative incidence of bleeding events was significantly greater for those participants, compared with participants receiving placebos [hazard ratio, 1.98; 95% confidence interval (CI), 1.19 to 3.28; P = 0.007]. Twenty-three participants in the placebo group and 44 participants in the active treatment group experienced a bleeding event (P = 0.006). There was no significant benefit of active treatment in the prevention of thrombosis (hazard ratio, 0.81; 95% CI, 0.47 to 1.40; P = 0.45), although there was a trend toward a benefit among participants who had not experienced previous graft thrombosis (hazard ratio, 0.52; 95% CI, 0.22 to 1.26; P = 0.14). In the hemodialysis population, therapy with aspirin and clopidogrel was associated with a significantly increased risk of bleeding and probably would not result in a reduced frequency of graft thrombosis.
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Affiliation(s)
- James S Kaufman
- Department of Veterans Affairs Boston Healthcare System and Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02130, USA.
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10
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Kelly BS, Heffelfinger SC, Whiting JF, Miller MA, Reaves A, Armstrong J, Narayana A, Roy-Chaudhury P. Aggressive venous neointimal hyperplasia in a pig model of arteriovenous graft stenosis. Kidney Int 2002; 62:2272-80. [PMID: 12427156 DOI: 10.1046/j.1523-1755.2002.00684.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Vascular access dysfunction is the most important cause of morbidity and hospitalization in the hemodialysis population in the United States at a cost of well over one billion dollars per annum. Venous neointimal hyperplasia characterized by stenosis and subsequent thrombosis, is the major cause of polytetrafluoroethylene (PTFE) dialysis graft failure. Despite the magnitude of the problem, there are currently no effective therapies for the prevention or treatment of venous neointimal hyperplasia in PTFE dialysis grafts. We believe that this is partly due to the lack of a validated large animal model of arteriovenous stenosis that could be used to test out novel interventions. METHODS Seven-centimeter PTFE loop grafts were placed between the femoral artery and vein of domestic pigs. The grafts were removed at 2, 4, 7, 14 and 28 days after surgery and subjected to a detailed histological and immunohistochemical examination. RESULTS Significant neointimal hyperplasia and venous stenosis developed by 28 days at the graft-vein anastomosis. There was minimal neointimal hyperplasia at the graft-artery anastomosis. Venous neointimal hyperplasia (VNH) was characterized by (a) the presence of smooth muscle cells/myofibroblasts; (b) angiogenesis within both the neointima and adventitia; and (c) the presence of an active macrophage cell layer lining the PTFE graft material. These results are very similar to the human lesion previously described by us in dialysis patients. CONCLUSIONS We have developed and validated a pig model of venous neointimal hyperplasia that is very similar to the human lesion. We believe that this is an ideal model in which to test out novel interventions for the prevention and treatment of clinical hemodialysis vascular access dysfunction.
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Affiliation(s)
- Burnett S Kelly
- Department of Surgery, University of Cincinnati, Cincinnati, Ohio 45267, USA
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11
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Saran R, Dykstra DM, Wolfe RA, Gillespie B, Held PJ, Young EW. Association between vascular access failure and the use of specific drugs: the Dialysis Outcomes and Practice Patterns Study (DOPPS). Am J Kidney Dis 2002; 40:1255-63. [PMID: 12460045 DOI: 10.1053/ajkd.2002.36895] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Several drugs have been proposed to improve vascular access patency based on favorable anticoagulant, antiplatelet, or vascular-remodeling properties. However, there is little evidence to guide drug strategies. METHODS The association between vascular access patency and the use of specific drugs was studied in a large sample of US hemodialysis patients enrolled in the Dialysis Outcomes and Practice Patterns Study, an international, prospective, observational study. In general, it was assumed that the drugs were prescribed for indications unrelated to vascular access preservation. Primary (unassisted survival) and secondary vascular access patency (assisted survival) were modeled using Cox regression (time to failure) adjusted for age, sex, race, body mass index, incidence to end-stage renal disease, diabetes mellitus, hypertension, valvular disease, chronic obstructive pulmonary disease, aortic aneurysm, deep-vein thrombosis, number of previous permanent accesses, and facility-clustering effects. Fistulae (n = 900) and grafts (n = 1,944) were evaluated separately. Technical failures within the first 30 days of surgical placement were excluded from the analysis. RESULTS Treatment with calcium channel blockers was associated with improved primary graft patency (relative risk [RR] for failure, 0.86; P = 0.034). Aspirin therapy was associated with better secondary graft patency (RR, 0.70; P < 0.001). Treatment with angiotensin-converting enzyme inhibitors was associated with significantly better secondary fistula patency (RR, 0.56; P = 0.010). Patients administered warfarin showed worse primary graft patency (RR, 1.33; P = 0.037). CONCLUSION These findings should help guide clinical trial priorities toward vascular access preservation using one or more of the agents that show significant risk reduction for access failure in this study.
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Affiliation(s)
- Rajiv Saran
- University Renal Research and Education Association, University of Michigan, Ann Arbor, MI, USA.
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12
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Affiliation(s)
- R Vanholder
- Department of Internal Medicine, University Hospital, Gent, Belgium.
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13
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Gajdos M, Mongiellová V, Huttová D, Cibulová L, Krivosíková Z, Spustová V, Dzúrik R. Ciprofibrate increases plasma concentration of platelet-derived growth factor AB in patients with advanced atherosclerosis and hyperlipidemia independently of its hypolipidemic effects. J Cardiovasc Pharmacol 2001; 38:651-6. [PMID: 11602811 DOI: 10.1097/00005344-200111000-00001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Fibrates, besides their hypolipidemic action, share alternative effects, such as decreased plasma fibrinogen and uric acid levels. Because of their complex action, additional effects have been investigated. A group of 23 patients with clinical signs of atherosclerosis and hyperlipoproteinemia was randomly allocated after a 1-month washout period and treated with either 100 mg/d of ciprofibrate or 100 mg/d of aspirin for 2 months. Patients were then treated with a combination of these two agents for the next 2 months. Ciprofibrate decreased plasma concentrations of triglycerides (-29%) and very-low-density lipoprotein cholesterol (-27%) in monotherapy and a larger reduction was observed if ciprofibrate was added to the aspirin therapy: triglycerides (-39%), very-low-density lipoprotein cholesterol (-33%), total cholesterol (-18%), low-density lipoprotein cholesterol (-17%), and increased high-density lipoprotein cholesterol (+36%). Ciprofibrate increased plasma levels of platelet-derived growth factor (PDGF) AB in both monotherapy patients (+162.9 pg/ml, +297%) and in aspirin-pretreated patients (+129.8 pg/ml, +134%); the increase of PDGF AB platelet store was significant only in aspirin-pretreated patients (+11.1 ng/ml, +51%). Aspirin in monotherapy did not modulate either plasma or platelet store of PDGF AB. Ciprofibrate did not inhibit thromboxane B 2 synthesis in platelets. Aspirin did not influence plasma thromboxane B 2 concentration at all, whereas it decreased thromboxane B 2 platelet production markedly in monotherapy (-85%) and in combination with ciprofibrate (-91%). Ciprofibrate increases PDGF AB content, which is amplified by aspirin pretreatment without correlation with its hypolipidemic action. The increase of PDGF production is suggested to participate in plaque stabilization.
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Affiliation(s)
- M Gajdos
- Institute of Preventive and Clinical Medicine, Department of Pharmacotherapy, Bratislava, Slovak Republic.
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15
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Joseph S, Adler S. Vascular access problems in dialysis patients: pathogenesis and strategies for management. HEART DISEASE (HAGERSTOWN, MD.) 2001; 3:242-7. [PMID: 11975801 DOI: 10.1097/00132580-200107000-00007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Repetitive hemodialysis was made possible through the development of a chronic means of accessing the circulation. This was accomplished through the use of arteriovenous fistulae or grafts, using autologous veins or synthetic materials. Although the arteriovenous fistula remains the access of choice, synthetic arteriovenous grafts are used in most patients because of problems with late referral to a nephrologist and poor vasculature. This article describes the means of accessing the circulation for hemodialysis, the pathogenesis of access failure through progressive stenosis followed by thrombosis, methods of detecting access dysfunction before thrombosis, and therapeutic options. Although angiographic or surgical intervention remain the mainstays of management, medical treatments to decrease stenosis and delay thrombosis are currently under investigation.
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Affiliation(s)
- S Joseph
- Division of Nephrology, Department of Medicine, New York Medical College Valhalla, New York 10595, USA
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17
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Smits JH, van der Linden J, Blankestijn PJ, Rabelink TJ. Coagulation and haemodialysis access thrombosis. Nephrol Dial Transplant 2000; 15:1755-60. [PMID: 11071961 DOI: 10.1093/ndt/15.11.1755] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- J H Smits
- Department of Nephrology, University Medical Center, Utrecht, Utrecht, The Netherlands
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18
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Affiliation(s)
- J S Kaufman
- Department of Medicine, VA Boston Healthcare System, MA 02130, USA.
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Fujita H, Saito F, Sawada T, Kushiro T, Yagi H, Kanmatsuse K. Lipoxygenase inhibition decreases neointimal formation following vascular injury. Atherosclerosis 1999; 147:69-75. [PMID: 10525127 DOI: 10.1016/s0021-9150(99)00165-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Our aim was to assess the potential role of lipoxygenase (LO) products in neointimal formation following vascular injury. We investigated the effect of LO pathway inhibition, by phenidone, on the concentration of 12- and 5-hydroxyeicosatetraenoic acid (12- and 5-HETE) in rat whole blood and in aortic tissue. We also examined the effect of phenidone on myoneointimal formation in balloon-injured rat carotid arteries. Phenidone significantly decreases the concentration of HETEs in aortic tissue, and decreases neointimal size even though there is no difference in the BrdU index. These data indicate that the LO product participates in developing neointima following balloon-induced vascular injury, and that the LO blocker phenidone decreases neointimal size possibly by suppressing migration of smooth muscle cells.
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Affiliation(s)
- H Fujita
- Department of Cardiology, Surugadai Nihon University Hospital, 1-8-13, Kandasurugadai, Chiyoda-ku, Tokyo, Japan
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Abstract
Vascular access dysfunction continues to result in substantial morbidity for chronic hemodialysis patients. Pharmacologic and molecular biologic approaches to prevention of vascular access dysfunction, if clinically successful, will be cost effective and improve quality of life for chronic dialysis patients. This review summarizes currently available information and future prospects in pharmacologic and molecular biologic approaches to preventing vascular access stenosis.
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Affiliation(s)
- J Himmelfarb
- Division of Nephrology, Maine Medical Center, Portland 04102, USA.
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Abstract
Recent evidence suggests that the cost as well as the morbidity associated with the maintenance of hemodialysis access is increasing rapidly; currently, the cost exceeds 1 billion dollars and access related hospitalization accounts for 25% of all hospital admissions in the U.S.A. This increase in cost and morbidity has been associated with several epidemiological trends that may contribute to access failure. These include late patient referral to nephrologists and surgeons, late planning of vascular access as well as a shift from A-V fistulaes to PTFE grafts and temporary catheters, which have a higher failure rate. The reasons for this shift in the types of access is multifactorial and is not explained by changes in the co-morbidities of patients presenting to dialysis. Surgical preference and training also appear to play an important role in the large regional variation and patency rate of these PTFE grafts. We propose a program for early placement of A-V fistulae, a continuous quality improvement, multidisciplinary program to monitor access outcome, the development of new biomaterials, and a research plan to investigate pharmacological intervention to reduce development of stenosis and clinical interventions to treat those that do develop, prior to thrombosis.
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Affiliation(s)
- R Hakim
- Vanderbilt University Medical Center, Department of Medicine, Nashville, Tennessee, USA
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