ASAIO Journal 2014
Arteriovenous Fistula Survival with Buttonhole (Constant Site) Cannulation for Hemodialysis Access Hala Kandil,* Sophie Collier,* Enat Yewetu,* Jennifer Cross,† and Andrew Davenport†
Buttonhole needling for arteriovenous fistulae (AVF) has increased in popularity among dialysis centers. Concerns have been raised about the risks of infection, so we reviewed our experience of buttonhole needling in 227 adult patients on hemodialysis. The mean buttonhole AVF survival was 27.0 months, in 227 patients, 61.1% male, mean age 63.8 ± 15.5 years, 45.8% with diabetes mellitus, median dialysis vintage 19 months (6.5–42.8). Ninety-six patients transferred to rope ladder AVF cannulation, because of cannulation failure in 25%, persistent bleeding at the needling site in 24%, fistula thrombosis in 14%, and infections in 15%. Because of persistent methicillin-sensitive Staphylococcus aureus (MSSA) or methicillin-resistant S. aureus (MRSA) colonization, 18.8% discontinued buttonhole needling. Transfer from buttonhole needling was more common for people with diabetes (X2 = 6.57; p = 0.035), older patients (odds ratio, 0.985; p = 0.007), and persistent MSSA/MRSA colonization (odds ratio, 0.88; p = 0.037). Eleven episodes of suspected buttonhole S. aureus bacteremia occurred giving a bacteremia rate of 2.94 per 100 patient years, and 15 local infections giving an infection rate of 4.01 per 100 patient years. In this large series of buttonhole AVF access, although infection rates were increased, more patients discontinued buttonhole needling because of technical cannulation problems and persistent bleeding from needle tracks. ASAIO Journal 2014; 60:95–98.
illness. Some patients, particularly children, may be needle phobic. The recent introduction of less sharp or “blunt” needles led to a resurgence in constant site or buttonhole needling4,5 compared with the standard rope ladder technique, in which the fistula is needled at different sites along the superficial course of the draining vein from the fistula, with reports of less pain and shorter times for needle puncture sites to stop bleeding at the end of the dialysis session.6 After an initial series of studies advocating the advantages of buttonhole technique,7,8 there have been subsequent reports not only failing to show an advantage for buttonhole access9,10 but also reporting an increased infection risk10 with the technique, because each time the fistula is needled, a scab from the previous venipuncture must be removed. Despite the recent enthusiasm for the buttonhole or constant needling-site technique, there are very little data in the literature on fistula survival using this technique, as such we audited our buttonhole needling experience to determine whether the increased use of this technique was associated with an increased complication rate. Methods Technique and Patients After the introduction of the buttonhole needling technique into one of our satellite dialysis centers, the procedure was extended to all satellite dialysis units under the care of the Royal Free Hospital, between November 2007 and March 2012 with buttonhole fistulae access created in 227 adult patients, out of a prevalent hemodialysis population of approximately 650 patients with a 60% fistula access rate. As this technique was rolled out to centers, buttonhole cannulation was developed in both incident and prevalent hemodialysis patients. However, buttonhole cannulation was not attempted in patients being worked up for living donor transplantation. Data on buttonhole access were recorded prospectively, with all dialysis sessions and technical problems with access recorded. All patients underwent dialysis thrice weekly using bolus lowmolecular-weight heparin, tinzaparin median dose 2,500 IU, range 0–5,000 IU (Leo Laboratories, Copenhagen, Denmark) for anticoagulation,11 using high-flux dialyzers (Nipro Corporation, Osaka, Japan).12 To create the buttonhole track, one experienced dialysis nurse, the named tracker, needled the fistula, with sharp 25 or 20 mm steel alloy needles (Nipro Corporation). A tourniquet was used to locate and stabilize the vein as necessary. The needling angle and depth were determined and recorded pictorially for reference by the principal tracker. During track development, a maximum of two trackers were used. If the tracker was unavailable, or there was any difficulty accessing
Key Words: hemodialysis, arteriovenous fistula, cannulation, buttonhole, bacteremia
A
rteriovenous fistulae are recommended by several clinical guidelines committees as the vascular access of choice for routine outpatient hemodialysis.1,2 However, arteriovenous fistulae are not without their own complications, ranging from infection, aneurysm formation, anastomotic or more proximal stenoses, thrombosis, vascular steal and increased risk of carpal tunnel syndrome, and even high-output cardiac failure.3 Patients are sometimes reluctant to consider fistulae, as from a psychological view they are a visible sign of their
From the *Department of Microbiology, Royal Free Hospital, London, United Kingdom; and †UCL Centre for Nephrology, Royal Free Hospital, London, United Kingdom. Submitted for consideration August 2013; accepted for publication in revised form September 2013. Disclosure: The authors have no conflicts of interest to report. Supported by Royal Free Hospital, London, United Kingdom. Reprint Requests: Andrew Davenport, UCL Centre for Nephrology, Royal Free Hospital, Rowland Hill Street, London NW3 2PF, United Kingdom. Email: [email protected]. Copyright © 2013 by the American Society for Artificial Internal Organs DOI: 10.1097/MAT.0000000000000018
95
96 KANDIL et al. the track, an alternative sharp needle site was used at least 3 cm from the site. Before any cannulation, the arm and cannulation area were washed using soap and water and then 2% chlorhexidine in 70% alcohol wipes (Clinell wipes; Gamma Healthcare Ltd., London, United Kingdom). Scabs were routinely removed from the previous dialysis session cannulation site, and if not removed by simple cleaning were removed using an 18 gauge blunt red fill needle (1.2 mm × 40 mm). Once the scab had been removed, the area was again cleaned with chlorhexidine and alcohol wipes. Topical antibiotics were not prescribed. The buttonhole site was cannulated with a blunt needle (Kimal, Uxbridge, Middlesex, United Kingdom). If there was resistance to the blunt needle, then it was withdrawn and a sharp needle used instead at an alternative site. Blunt needles would then be tried again at the following hemodialysis session. Once blunt needle cannulation could easily be achieved by the tracker, other members of the dialysis nursing team performed cannulation by using blunt needles. Typically eight to 10 cannulations were required to create the blunt needle tracts. As all methicillin-sensitive Staphyloccus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) bacteremias are reportable to the UK Department of Health as a mandatory requirement, patients were regularly screened thrice monthly for nasal carriage of MSSA and MRSA. Our decolonization policy combined 5 days of skin and hair washing with chlorhexidine with nasal mupirocin, or hibitane if mupirocin resistant. Approval was granted under the UK National Health Service (NHS) audit and clinical service development program for this retrospective audit of clinical practice. Statistical Analysis Results are expressed as mean ± standard error, or median and interquartile range, or percentages. Statistical analysis was performed by Student’s paired t-test for parametric and the Wilcoxon rank sum pair test for nonparametric data, with Bonferroni correction where appropriate, and backward Cox covariate regression model performed after log transformation of nonparametric data, using the original center which created the buttonhole fistula, final dialysis center, age, sex, racial origin, diabetic status, dialysis vintage in months, cardiovascular comorbidity, MSSA and MRSA carriage and number of positive nasal swabs, and episodes of bacteremia. In addition, the chi-square test, with Yate’s correction, was also used. Statistical analysis used Prism (GraphPad version 5; GraphPad Software, San Diego, CA) and SPSS (version 14.0; University of Chicago, Chicago, IL), statistical significance was taken at or below the 5% level.
Figure 1. Buttonhole arteriovenous fistula survival curve.
with a working fistula, the mean buttonhole fistula survival time was 27.0 months (Figure 1). The commonest cause of patients switching back to sharp needles and rope ladder needling technique was the inability to cannulate the buttonhole tract, followed by persistent bleeding at one of the buttonhole needling sites (Figure 2). On at least one occasion, 53.1% of patients were carriers of MSSA or MRSA, range one to 25 positive results. Buttonhole fistula survival was not affected by sex, ethnicity, or dialysis vintage, but was lower for patients on diabetes (X2 = 6.57; p = 0.035) and those with fistula failure were older 67.0 ± 13.7 years versus 60.6 ± 16.2 years; p < 0.05. A single episode of MSSA and MRSA carriage was not associated with fistula failure (X2 = 0.67; p = 0.25). Most buttonhole fistulae were created in three centers, 29%, 30.8%, and 30.4%, respectively, and although some patients did move centers, there was no effect in terms of fistula failure and either center where the buttonhole was created, or center in which failure occurred. Cox regression analysis was performed to identify
Results Buttonhole access was developed in 227 adult patients, 61.1% male, mean age 63.8 ± 15.5 years, 45.8% with diabetes, and according to the self-reported UK NHS medical ethnicity records, 44.9% Caucasoid, 22.5% African or Afro-Caribbean, 26.4% South Asian, 4.4% Far Asian, and 1.8% other races who attended for thrice weekly outpatient dialysis, median dialysis vintage 19 months (6.5–42.8). Patients were followed up for a median of 16.8 months (9.8–29.4). After censoring for 10 patients who were transplanted and one patient who died
Figure 2. Causes of buttonhole arteriovenous fistula failure. SA, Staphylococcus aureus.
SURVIVAL OF BUTTONHOLE FISTULAE Table 1. Results of Cox Covariate Regression Analysis to Determine Causes of Buttonhole Fistula Survival
Variable Age Staphylococcus aureus swabs
Odds Ratio
95% Confidence Limits
p
0.826 0.968
0.736–0.928 0.944–0.988
0.001 0.002
Number of positive swabs for Staphylococcus aureus (both methicillin sensitive and resistant swabs).
causes of buttonhole fistula failure, adjusting for age, sex, dialysis vintage, diabetes, number of positive MSSA or MRSA swabs, and dialysis center (Table 1). Eleven episodes of S. aureus bacteremia (SAB) that could not be accounted for by a primary infection elsewhere occurred during 4487 buttonhole months, giving a bacteremia rate of 2.94 bacteremias per 100 patient treatment years. The source attributable to each episode of SAB was made after regular clinical assessment of the patient and a multidisciplinary team meeting discussion. In addition, there were an additional 15 local infections treated, giving an infection rate of 4.01 infections per 100 patient treatment years. Discussion These data confirm a number of other reports of increased infection associated with buttonhole fistulae.3,10 Other studies have shown that infection rates associated with buttonhole fistulae can be reduced by additional staff and patient education and training.13,14 Compared with other studies, our observed buttonhole technique–associated infection rates are lower. This may reflect different cleaning practices during fistula preparation and scab removal. Despite this, the observed infection rates remain significantly lower than those reported for central venous access catheters15 and central venous dialysis catheters with antibiotic catheter locks.16 Previous reports have suggested a bacteremia rate of 3.0 per 100 patient treatment years for children using a rope ladder needling technique,17 and varying rates in adults from 1.92 to 6.0 for in-center patients on dialysis ,18 with reports of up to 11.0/100 patient years for home hemodialysis patients.14 In addition to bacteremias, local soft-tissue infection rates around the buttonhole fistula site have been reported to range between 0.6 and 6.72 per 100 patient treatment years. Although the potential risk of infection is of course of great concern, we could not demonstrate any association between MSSA or MRSA nasal carriage and subsequent local fistula infections or bacteremic episodes, as approximately 50% of patients had a single positive nasal swab at some time during follow-up. However, for patients who were persistently MSSA or MRSA swab positive despite repeated decolonization, buttonhole access was switched to rope ladder with sharp needles to prevent possible infections. Other groups have suggested the use of topical antibiotics to the buttonhole sites such as mupirocin to reduce the risk of bacteremias, down from 11.0 to 1.1 per 100 patient years.14 In addition to the increased risk of infection with buttonhole access, we also noted a relatively high rate of technical failures and excessive bleeding from one of the needling sites. Factor reported to be important in developing and maintaining
97
buttonhole fistulae includes the number of trackers used to establish the initial tract, with lesser success associated with the greater number of trackers used.10 We relied on two experienced dialysis nurses in each dialysis center, with one of these nurses acting as the “tracker” for an individual patient, and only once the track had been fully developed, so that the “blunt” needle would readily pass through the track without difficulty and cannulate the fistula vein, were other dialysis trained nurses then allowed to cannulate the fistula using “blunt” needles. In cases of difficulties using a “blunt” needle, an alternative site was cannulated using a sharp needle. Although successful buttonhole access has been reported in studies of frequent dialysis and nocturnal dialysis,14 there have been concerns about tissue healing with the use of a constant needling site. We found that technical complications with buttonholing were more likely to occur with older patients and also patients with diabetes, and this may reflect differences in underlying dermal collagen matrix and wound healing.19,20 The major technical problems encountered were on the one hand the inability to needle the buttonhole track, most commonly because of intimal hyperplasia as a consequence over overzealous intimal repair and on other hand because of excessive bleeding, which typically results from high pressure developing secondary to an area of stenosis just downstream to the buttonhole site (personal communication, C. Forman, August 29, 2013), developing secondary to repeated trauma, presumably secondary to poor needling technique by different nurses despite development of the buttonhole track. In addition, excessive bleeding can also arise because of some buttonholes being made larger than necessary. Vaux et al.21 have recently reported improved buttonhole cannulation success using a preformed polycarbonate peg, and as such this may limit the size of the cannulation track and potentially reduce the risk of excessive bleeding. Despite the technical failures, our fistula survival was more than 50% after 2 years, which compares favorably with reports of native arteriovenous fistulae patency in similar age groups using standard needling techniques, with 2 year patency rates of 25–45%,22,23 and others with a median fistula patency rate of 10 months.24 A recent controlled trial reported 100% 12 month success for buttonhole cannulation developed with a preformed peg technique compared with 83%, compared with standard needling techniques.21 However, the standard needling group had suffered more technical access failures before trial entry. Reliable vascular access remains the Achilles’ heel of hemodialysis, and repeated needling of fistulae can lead to the development of stenoses, aneurysm formation, and thrombosis.3 The risk of developing these complications has been reported to be greater with the standard rope ladder technique rather than buttonhole,7,8 and although buttonholing is not without its own technical problems, our study suggests that buttonhole fistulae in our center have a longer survival than reported for standard rope ladder needling in other centers.18–20 The question of why buttonholing has not become more popular arises,25 as patient reported experiences are favorable, particularly in terms of less cannulation pain with needles.6 This probably relates to the time it takes a single experienced tracker to develop a reliable site in a busy dialysis unit. Although the buttonhole technique has been successfully used for many years for home hemodialysis patients,26 centers
98 KANDIL et al. that have used multiple trackers, or sharp needles when it has been difficult to place blunt needles, typically report inferior outcomes compared with rope ladder needling.10,27 Intuitively, a buttonhole track created by a patient inserting their own needles is less likely to suffer traumatic damage when tracks are made by a limited number of skilled nurses, and then needled by general dialysis staff. This has led to the development of different techniques designed to improve the initial development of the track with recent reports of using plastic inserts placed into the needle track after needle removal, or polyurethane catheters left in situ after one dialysis session until the start of the subsequent dialysis to speed up development of the needle track.21,28,29 The question arises as to whether these developments will improve not only the increased risk of infection but also the technical problems we encountered of inability to cannulate the buttonhole track because of closure and excessive bleeding from the needling sites remains to be answered by further studies. References 1. Canadian Society of Nephrology (CSN): Report of the canadian society of nephrology vascular access working group. Semin Dia 25: 22–25, 2012. 2. Fluck R, Kumwenda M: Renal association clinical practice guideline on vascular access for haemodialysis. Nephron Clin Pract 118 (suppl 1): c225–c240, 2011. 3. Kumbar L: Complications of arteriovenous fistulae: Beyond venous stenosis. Adv Chronic Kidney Dis 19: 195–201, 2012. 4. Twardowski ZJ: Constant site (button hole) method of needle insertion for haemodialysis. Dial Transplant 24: 559–560, 1995. 5. Twardowski Z, Kubara H: Different sites versus constant site of needle insertion into arteriovenous fistulas for treatment by repeated dialysis. Dial Transplant 8: 978–980, 1979. 6. Ward J, Shaw K, Davenport A: Patients’ perspectives of constant-site (buttonhole) cannulation for haemodialysis access. Nephron Clin Pract 116: c123–c127, 2010. 7. van Loon MM, Goovaerts T, Kessels AG, van der Sande FM, Tordoir JH: Buttonhole needling of haemodialysis arteriovenous fistulae results in less complications and interventions compared to the rope-ladder technique. Nephrol Dial Transplant 25: 225–230, 2010. 8. Verhallen AM, Kooistra MP, van Jaarsveld BC: Cannulating in haemodialysis: Rope-ladder or buttonhole technique? Nephrol Dial Transplant 22: 2601–2604, 2007. 9. Chow J, Rayment G, San Miguel S, Gilbert M: A randomised controlled trial of buttonhole cannulation for the prevention of fistula access complications. J Ren Care 37: 85–93, 2011. 10. MacRae JM, Ahmed SB, Atkar R, Hemmelgarn BR: A randomized trial comparing buttonhole with rope ladder needling in conventional hemodialysis patients. Clin J Am Soc Nephrol 7: 1632–1638, 2012. 11. Davenport A: Review article: Low-molecular-weight heparin as an alternative anticoagulant to unfractionated heparin for routine outpatient haemodialysis treatments. Nephrology (Carlton) 14: 455–461, 2009. 12. Vernon K, Peasegood J, Riddell A, Davenport A: Dialyzers designed to increase internal filtration do not result in significantly increased platelet activation and thrombin generation. Nephron Clin Pract 117: c403–c408, 2011.
13. Labriola L, Crott R, Desmet C, André G, Jadoul M: Infectious complications following conversion to buttonhole cannulation of native arteriovenous fistulas: A quality improvement report. Am J Kidney Dis 57: 442–448, 2011. 14. Nesrallah GE, Cuerden M, Wong JH, Pierratos A: Staphylococcus aureus bacteremia and buttonhole cannulation: Long-term safety and efficacy of mupirocin prophylaxis. Clin J Am Soc Nephrol 5: 1047–1053, 2010. 15. Crowley L, Wilson J, Guy R, Pitcher D, Fluck R: Chapter 12 epidemiology of Staphylococcus aureus bacteraemia amongst patients receiving dialysis for established renal failure in England in 2009 to 2011: A joint report from the health protection agency and the UK renal registry. Nephron Clin Pract 120 (suppl 1): c233–245, 2012. 16. Moran J, Sun S, Khababa I, Pedan A, Doss S, Schiller B: A randomized trial comparing gentamicin/citrate and heparin locks for central venous catheters in maintenance hemodialysis patients. Am J Kidney Dis 59: 102–107, 2012. 17. Ma A, Shroff R, Hothi D, et al: A comparison of arteriovenous fistulas and central venous lines for long-term chronic haemodialysis. Pediatr Nephrol 28: 321–326, 2013. 18. Gilad J, Eskira S, Schlaeffer F, et al: Surveillance of chronic haemodialysis-associated infections in southern Israel. Clin Microbiol Infect 11: 547–552, 2005. 19. Duncan HJ, Faris IB: Skin vascular resistance and skin perfusion pressure as predictors of healing of ischemic lesion of the lower limb: Influences of diabetes mellitus, hypertension, and age. Surgery 99: 432–438, 1986. 20. Niu Y, Cao X, Song F, et al: Reduced dermis thickness and AGE accumulation in diabetic abdominal skin. Int J Low Extrem Wounds 11: 224–230, 2012. 21. Vaux E, King J, Lloyd S, et al: Effect of buttonhole cannulation with a polycarbonate PEG on in-center hemodialysis fistula outcomes: A randomized controlled trial. Am J Kidney Dis 62: 81–88, 2013. 22. Renaud CJ, Pei JH, Lee EJ, Robless PA, Vathsala A: Comparative outcomes of primary autogenous fistulas in elderly, multiethnic Asian hemodialysis patients. J Vasc Surg 56: 433–439, 2012. 23. Schinstock CA, Albright RC, Williams AW, et al: Outcomes of arteriovenous fistula creation after the Fistula First Initiative. Clin J Am Soc Nephrol 6: 1996–2002, 2011. 24. Schild AF, Perez E, Gillaspie E, Seaver C, Livingstone J, Thibonnier A: Arteriovenous fistulae vs. arteriovenous grafts: A retrospective review of 1,700 consecutive vascular access cases. J Vasc Access 9: 231–235, 2008. 25. Murcutt G: Buttonhole cannulation: Should this become the default technique for dialysis patients with native fistulas? Summary of the EDTNA/ERCA Journal Club discussion Autumn 2007. J Ren Care 34: 101–108, 2008. 26. Pipkin M, Craft V, Spencer M, Lockridge RS Jr: Six years of experience with nightly home hemodialysis access. Hemodial Int 8: 349–353, 2004. 27. van Loon MM, Kessels AG, Kessel AG, van der Sande FM, Tordoir JH: Cannulation practice patterns in haemodialysis vascular access: Predictors for unsuccessful cannulation. J Ren Care 35: 82–89, 2009. 28. Marticorena RM, Hunter J, Cook R, et al: A simple method to create buttonhole cannulation tracks in a busy hemodialysis unit. Hemodial Int 13: 316–321, 2009. 29. Toma S, Shinzato T, Fukui H, et al: A timesaving method to create a fixed puncture route for the buttonhole technique. Nephrol Dial Transplant 18: 2118–2121, 2003.
Arteriovenous Fistula Survival with Buttonhole (Constant Site) Cannulation for Hemodialysis Access Hala Kandil,* Sophie Collier,* Enat Yewetu,* Jennifer Cross,† and Andrew Davenport†
Buttonhole needling for arteriovenous fistulae (AVF) has increased in popularity among dialysis centers. Concerns have been raised about the risks of infection, so we reviewed our experience of buttonhole needling in 227 adult patients on hemodialysis. The mean buttonhole AVF survival was 27.0 months, in 227 patients, 61.1% male, mean age 63.8 ± 15.5 years, 45.8% with diabetes mellitus, median dialysis vintage 19 months (6.5–42.8). Ninety-six patients transferred to rope ladder AVF cannulation, because of cannulation failure in 25%, persistent bleeding at the needling site in 24%, fistula thrombosis in 14%, and infections in 15%. Because of persistent methicillin-sensitive Staphylococcus aureus (MSSA) or methicillin-resistant S. aureus (MRSA) colonization, 18.8% discontinued buttonhole needling. Transfer from buttonhole needling was more common for people with diabetes (X2 = 6.57; p = 0.035), older patients (odds ratio, 0.985; p = 0.007), and persistent MSSA/MRSA colonization (odds ratio, 0.88; p = 0.037). Eleven episodes of suspected buttonhole S. aureus bacteremia occurred giving a bacteremia rate of 2.94 per 100 patient years, and 15 local infections giving an infection rate of 4.01 per 100 patient years. In this large series of buttonhole AVF access, although infection rates were increased, more patients discontinued buttonhole needling because of technical cannulation problems and persistent bleeding from needle tracks. ASAIO Journal 2014; 60:95–98.
illness. Some patients, particularly children, may be needle phobic. The recent introduction of less sharp or “blunt” needles led to a resurgence in constant site or buttonhole needling4,5 compared with the standard rope ladder technique, in which the fistula is needled at different sites along the superficial course of the draining vein from the fistula, with reports of less pain and shorter times for needle puncture sites to stop bleeding at the end of the dialysis session.6 After an initial series of studies advocating the advantages of buttonhole technique,7,8 there have been subsequent reports not only failing to show an advantage for buttonhole access9,10 but also reporting an increased infection risk10 with the technique, because each time the fistula is needled, a scab from the previous venipuncture must be removed. Despite the recent enthusiasm for the buttonhole or constant needling-site technique, there are very little data in the literature on fistula survival using this technique, as such we audited our buttonhole needling experience to determine whether the increased use of this technique was associated with an increased complication rate. Methods Technique and Patients After the introduction of the buttonhole needling technique into one of our satellite dialysis centers, the procedure was extended to all satellite dialysis units under the care of the Royal Free Hospital, between November 2007 and March 2012 with buttonhole fistulae access created in 227 adult patients, out of a prevalent hemodialysis population of approximately 650 patients with a 60% fistula access rate. As this technique was rolled out to centers, buttonhole cannulation was developed in both incident and prevalent hemodialysis patients. However, buttonhole cannulation was not attempted in patients being worked up for living donor transplantation. Data on buttonhole access were recorded prospectively, with all dialysis sessions and technical problems with access recorded. All patients underwent dialysis thrice weekly using bolus lowmolecular-weight heparin, tinzaparin median dose 2,500 IU, range 0–5,000 IU (Leo Laboratories, Copenhagen, Denmark) for anticoagulation,11 using high-flux dialyzers (Nipro Corporation, Osaka, Japan).12 To create the buttonhole track, one experienced dialysis nurse, the named tracker, needled the fistula, with sharp 25 or 20 mm steel alloy needles (Nipro Corporation). A tourniquet was used to locate and stabilize the vein as necessary. The needling angle and depth were determined and recorded pictorially for reference by the principal tracker. During track development, a maximum of two trackers were used. If the tracker was unavailable, or there was any difficulty accessing
Key Words: hemodialysis, arteriovenous fistula, cannulation, buttonhole, bacteremia
A
rteriovenous fistulae are recommended by several clinical guidelines committees as the vascular access of choice for routine outpatient hemodialysis.1,2 However, arteriovenous fistulae are not without their own complications, ranging from infection, aneurysm formation, anastomotic or more proximal stenoses, thrombosis, vascular steal and increased risk of carpal tunnel syndrome, and even high-output cardiac failure.3 Patients are sometimes reluctant to consider fistulae, as from a psychological view they are a visible sign of their
From the *Department of Microbiology, Royal Free Hospital, London, United Kingdom; and †UCL Centre for Nephrology, Royal Free Hospital, London, United Kingdom. Submitted for consideration August 2013; accepted for publication in revised form September 2013. Disclosure: The authors have no conflicts of interest to report. Supported by Royal Free Hospital, London, United Kingdom. Reprint Requests: Andrew Davenport, UCL Centre for Nephrology, Royal Free Hospital, Rowland Hill Street, London NW3 2PF, United Kingdom. Email: [email protected]. Copyright © 2013 by the American Society for Artificial Internal Organs DOI: 10.1097/MAT.0000000000000018
95
96 KANDIL et al. the track, an alternative sharp needle site was used at least 3 cm from the site. Before any cannulation, the arm and cannulation area were washed using soap and water and then 2% chlorhexidine in 70% alcohol wipes (Clinell wipes; Gamma Healthcare Ltd., London, United Kingdom). Scabs were routinely removed from the previous dialysis session cannulation site, and if not removed by simple cleaning were removed using an 18 gauge blunt red fill needle (1.2 mm × 40 mm). Once the scab had been removed, the area was again cleaned with chlorhexidine and alcohol wipes. Topical antibiotics were not prescribed. The buttonhole site was cannulated with a blunt needle (Kimal, Uxbridge, Middlesex, United Kingdom). If there was resistance to the blunt needle, then it was withdrawn and a sharp needle used instead at an alternative site. Blunt needles would then be tried again at the following hemodialysis session. Once blunt needle cannulation could easily be achieved by the tracker, other members of the dialysis nursing team performed cannulation by using blunt needles. Typically eight to 10 cannulations were required to create the blunt needle tracts. As all methicillin-sensitive Staphyloccus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) bacteremias are reportable to the UK Department of Health as a mandatory requirement, patients were regularly screened thrice monthly for nasal carriage of MSSA and MRSA. Our decolonization policy combined 5 days of skin and hair washing with chlorhexidine with nasal mupirocin, or hibitane if mupirocin resistant. Approval was granted under the UK National Health Service (NHS) audit and clinical service development program for this retrospective audit of clinical practice. Statistical Analysis Results are expressed as mean ± standard error, or median and interquartile range, or percentages. Statistical analysis was performed by Student’s paired t-test for parametric and the Wilcoxon rank sum pair test for nonparametric data, with Bonferroni correction where appropriate, and backward Cox covariate regression model performed after log transformation of nonparametric data, using the original center which created the buttonhole fistula, final dialysis center, age, sex, racial origin, diabetic status, dialysis vintage in months, cardiovascular comorbidity, MSSA and MRSA carriage and number of positive nasal swabs, and episodes of bacteremia. In addition, the chi-square test, with Yate’s correction, was also used. Statistical analysis used Prism (GraphPad version 5; GraphPad Software, San Diego, CA) and SPSS (version 14.0; University of Chicago, Chicago, IL), statistical significance was taken at or below the 5% level.
Figure 1. Buttonhole arteriovenous fistula survival curve.
with a working fistula, the mean buttonhole fistula survival time was 27.0 months (Figure 1). The commonest cause of patients switching back to sharp needles and rope ladder needling technique was the inability to cannulate the buttonhole tract, followed by persistent bleeding at one of the buttonhole needling sites (Figure 2). On at least one occasion, 53.1% of patients were carriers of MSSA or MRSA, range one to 25 positive results. Buttonhole fistula survival was not affected by sex, ethnicity, or dialysis vintage, but was lower for patients on diabetes (X2 = 6.57; p = 0.035) and those with fistula failure were older 67.0 ± 13.7 years versus 60.6 ± 16.2 years; p < 0.05. A single episode of MSSA and MRSA carriage was not associated with fistula failure (X2 = 0.67; p = 0.25). Most buttonhole fistulae were created in three centers, 29%, 30.8%, and 30.4%, respectively, and although some patients did move centers, there was no effect in terms of fistula failure and either center where the buttonhole was created, or center in which failure occurred. Cox regression analysis was performed to identify
Results Buttonhole access was developed in 227 adult patients, 61.1% male, mean age 63.8 ± 15.5 years, 45.8% with diabetes, and according to the self-reported UK NHS medical ethnicity records, 44.9% Caucasoid, 22.5% African or Afro-Caribbean, 26.4% South Asian, 4.4% Far Asian, and 1.8% other races who attended for thrice weekly outpatient dialysis, median dialysis vintage 19 months (6.5–42.8). Patients were followed up for a median of 16.8 months (9.8–29.4). After censoring for 10 patients who were transplanted and one patient who died
Figure 2. Causes of buttonhole arteriovenous fistula failure. SA, Staphylococcus aureus.
SURVIVAL OF BUTTONHOLE FISTULAE Table 1. Results of Cox Covariate Regression Analysis to Determine Causes of Buttonhole Fistula Survival
Variable Age Staphylococcus aureus swabs
Odds Ratio
95% Confidence Limits
p
0.826 0.968
0.736–0.928 0.944–0.988
0.001 0.002
Number of positive swabs for Staphylococcus aureus (both methicillin sensitive and resistant swabs).
causes of buttonhole fistula failure, adjusting for age, sex, dialysis vintage, diabetes, number of positive MSSA or MRSA swabs, and dialysis center (Table 1). Eleven episodes of S. aureus bacteremia (SAB) that could not be accounted for by a primary infection elsewhere occurred during 4487 buttonhole months, giving a bacteremia rate of 2.94 bacteremias per 100 patient treatment years. The source attributable to each episode of SAB was made after regular clinical assessment of the patient and a multidisciplinary team meeting discussion. In addition, there were an additional 15 local infections treated, giving an infection rate of 4.01 infections per 100 patient treatment years. Discussion These data confirm a number of other reports of increased infection associated with buttonhole fistulae.3,10 Other studies have shown that infection rates associated with buttonhole fistulae can be reduced by additional staff and patient education and training.13,14 Compared with other studies, our observed buttonhole technique–associated infection rates are lower. This may reflect different cleaning practices during fistula preparation and scab removal. Despite this, the observed infection rates remain significantly lower than those reported for central venous access catheters15 and central venous dialysis catheters with antibiotic catheter locks.16 Previous reports have suggested a bacteremia rate of 3.0 per 100 patient treatment years for children using a rope ladder needling technique,17 and varying rates in adults from 1.92 to 6.0 for in-center patients on dialysis ,18 with reports of up to 11.0/100 patient years for home hemodialysis patients.14 In addition to bacteremias, local soft-tissue infection rates around the buttonhole fistula site have been reported to range between 0.6 and 6.72 per 100 patient treatment years. Although the potential risk of infection is of course of great concern, we could not demonstrate any association between MSSA or MRSA nasal carriage and subsequent local fistula infections or bacteremic episodes, as approximately 50% of patients had a single positive nasal swab at some time during follow-up. However, for patients who were persistently MSSA or MRSA swab positive despite repeated decolonization, buttonhole access was switched to rope ladder with sharp needles to prevent possible infections. Other groups have suggested the use of topical antibiotics to the buttonhole sites such as mupirocin to reduce the risk of bacteremias, down from 11.0 to 1.1 per 100 patient years.14 In addition to the increased risk of infection with buttonhole access, we also noted a relatively high rate of technical failures and excessive bleeding from one of the needling sites. Factor reported to be important in developing and maintaining
97
buttonhole fistulae includes the number of trackers used to establish the initial tract, with lesser success associated with the greater number of trackers used.10 We relied on two experienced dialysis nurses in each dialysis center, with one of these nurses acting as the “tracker” for an individual patient, and only once the track had been fully developed, so that the “blunt” needle would readily pass through the track without difficulty and cannulate the fistula vein, were other dialysis trained nurses then allowed to cannulate the fistula using “blunt” needles. In cases of difficulties using a “blunt” needle, an alternative site was cannulated using a sharp needle. Although successful buttonhole access has been reported in studies of frequent dialysis and nocturnal dialysis,14 there have been concerns about tissue healing with the use of a constant needling site. We found that technical complications with buttonholing were more likely to occur with older patients and also patients with diabetes, and this may reflect differences in underlying dermal collagen matrix and wound healing.19,20 The major technical problems encountered were on the one hand the inability to needle the buttonhole track, most commonly because of intimal hyperplasia as a consequence over overzealous intimal repair and on other hand because of excessive bleeding, which typically results from high pressure developing secondary to an area of stenosis just downstream to the buttonhole site (personal communication, C. Forman, August 29, 2013), developing secondary to repeated trauma, presumably secondary to poor needling technique by different nurses despite development of the buttonhole track. In addition, excessive bleeding can also arise because of some buttonholes being made larger than necessary. Vaux et al.21 have recently reported improved buttonhole cannulation success using a preformed polycarbonate peg, and as such this may limit the size of the cannulation track and potentially reduce the risk of excessive bleeding. Despite the technical failures, our fistula survival was more than 50% after 2 years, which compares favorably with reports of native arteriovenous fistulae patency in similar age groups using standard needling techniques, with 2 year patency rates of 25–45%,22,23 and others with a median fistula patency rate of 10 months.24 A recent controlled trial reported 100% 12 month success for buttonhole cannulation developed with a preformed peg technique compared with 83%, compared with standard needling techniques.21 However, the standard needling group had suffered more technical access failures before trial entry. Reliable vascular access remains the Achilles’ heel of hemodialysis, and repeated needling of fistulae can lead to the development of stenoses, aneurysm formation, and thrombosis.3 The risk of developing these complications has been reported to be greater with the standard rope ladder technique rather than buttonhole,7,8 and although buttonholing is not without its own technical problems, our study suggests that buttonhole fistulae in our center have a longer survival than reported for standard rope ladder needling in other centers.18–20 The question of why buttonholing has not become more popular arises,25 as patient reported experiences are favorable, particularly in terms of less cannulation pain with needles.6 This probably relates to the time it takes a single experienced tracker to develop a reliable site in a busy dialysis unit. Although the buttonhole technique has been successfully used for many years for home hemodialysis patients,26 centers
98 KANDIL et al. that have used multiple trackers, or sharp needles when it has been difficult to place blunt needles, typically report inferior outcomes compared with rope ladder needling.10,27 Intuitively, a buttonhole track created by a patient inserting their own needles is less likely to suffer traumatic damage when tracks are made by a limited number of skilled nurses, and then needled by general dialysis staff. This has led to the development of different techniques designed to improve the initial development of the track with recent reports of using plastic inserts placed into the needle track after needle removal, or polyurethane catheters left in situ after one dialysis session until the start of the subsequent dialysis to speed up development of the needle track.21,28,29 The question arises as to whether these developments will improve not only the increased risk of infection but also the technical problems we encountered of inability to cannulate the buttonhole track because of closure and excessive bleeding from the needling sites remains to be answered by further studies. References 1. Canadian Society of Nephrology (CSN): Report of the canadian society of nephrology vascular access working group. Semin Dia 25: 22–25, 2012. 2. Fluck R, Kumwenda M: Renal association clinical practice guideline on vascular access for haemodialysis. Nephron Clin Pract 118 (suppl 1): c225–c240, 2011. 3. Kumbar L: Complications of arteriovenous fistulae: Beyond venous stenosis. Adv Chronic Kidney Dis 19: 195–201, 2012. 4. Twardowski ZJ: Constant site (button hole) method of needle insertion for haemodialysis. Dial Transplant 24: 559–560, 1995. 5. Twardowski Z, Kubara H: Different sites versus constant site of needle insertion into arteriovenous fistulas for treatment by repeated dialysis. Dial Transplant 8: 978–980, 1979. 6. Ward J, Shaw K, Davenport A: Patients’ perspectives of constant-site (buttonhole) cannulation for haemodialysis access. Nephron Clin Pract 116: c123–c127, 2010. 7. van Loon MM, Goovaerts T, Kessels AG, van der Sande FM, Tordoir JH: Buttonhole needling of haemodialysis arteriovenous fistulae results in less complications and interventions compared to the rope-ladder technique. Nephrol Dial Transplant 25: 225–230, 2010. 8. Verhallen AM, Kooistra MP, van Jaarsveld BC: Cannulating in haemodialysis: Rope-ladder or buttonhole technique? Nephrol Dial Transplant 22: 2601–2604, 2007. 9. Chow J, Rayment G, San Miguel S, Gilbert M: A randomised controlled trial of buttonhole cannulation for the prevention of fistula access complications. J Ren Care 37: 85–93, 2011. 10. MacRae JM, Ahmed SB, Atkar R, Hemmelgarn BR: A randomized trial comparing buttonhole with rope ladder needling in conventional hemodialysis patients. Clin J Am Soc Nephrol 7: 1632–1638, 2012. 11. Davenport A: Review article: Low-molecular-weight heparin as an alternative anticoagulant to unfractionated heparin for routine outpatient haemodialysis treatments. Nephrology (Carlton) 14: 455–461, 2009. 12. Vernon K, Peasegood J, Riddell A, Davenport A: Dialyzers designed to increase internal filtration do not result in significantly increased platelet activation and thrombin generation. Nephron Clin Pract 117: c403–c408, 2011.
13. Labriola L, Crott R, Desmet C, André G, Jadoul M: Infectious complications following conversion to buttonhole cannulation of native arteriovenous fistulas: A quality improvement report. Am J Kidney Dis 57: 442–448, 2011. 14. Nesrallah GE, Cuerden M, Wong JH, Pierratos A: Staphylococcus aureus bacteremia and buttonhole cannulation: Long-term safety and efficacy of mupirocin prophylaxis. Clin J Am Soc Nephrol 5: 1047–1053, 2010. 15. Crowley L, Wilson J, Guy R, Pitcher D, Fluck R: Chapter 12 epidemiology of Staphylococcus aureus bacteraemia amongst patients receiving dialysis for established renal failure in England in 2009 to 2011: A joint report from the health protection agency and the UK renal registry. Nephron Clin Pract 120 (suppl 1): c233–245, 2012. 16. Moran J, Sun S, Khababa I, Pedan A, Doss S, Schiller B: A randomized trial comparing gentamicin/citrate and heparin locks for central venous catheters in maintenance hemodialysis patients. Am J Kidney Dis 59: 102–107, 2012. 17. Ma A, Shroff R, Hothi D, et al: A comparison of arteriovenous fistulas and central venous lines for long-term chronic haemodialysis. Pediatr Nephrol 28: 321–326, 2013. 18. Gilad J, Eskira S, Schlaeffer F, et al: Surveillance of chronic haemodialysis-associated infections in southern Israel. Clin Microbiol Infect 11: 547–552, 2005. 19. Duncan HJ, Faris IB: Skin vascular resistance and skin perfusion pressure as predictors of healing of ischemic lesion of the lower limb: Influences of diabetes mellitus, hypertension, and age. Surgery 99: 432–438, 1986. 20. Niu Y, Cao X, Song F, et al: Reduced dermis thickness and AGE accumulation in diabetic abdominal skin. Int J Low Extrem Wounds 11: 224–230, 2012. 21. Vaux E, King J, Lloyd S, et al: Effect of buttonhole cannulation with a polycarbonate PEG on in-center hemodialysis fistula outcomes: A randomized controlled trial. Am J Kidney Dis 62: 81–88, 2013. 22. Renaud CJ, Pei JH, Lee EJ, Robless PA, Vathsala A: Comparative outcomes of primary autogenous fistulas in elderly, multiethnic Asian hemodialysis patients. J Vasc Surg 56: 433–439, 2012. 23. Schinstock CA, Albright RC, Williams AW, et al: Outcomes of arteriovenous fistula creation after the Fistula First Initiative. Clin J Am Soc Nephrol 6: 1996–2002, 2011. 24. Schild AF, Perez E, Gillaspie E, Seaver C, Livingstone J, Thibonnier A: Arteriovenous fistulae vs. arteriovenous grafts: A retrospective review of 1,700 consecutive vascular access cases. J Vasc Access 9: 231–235, 2008. 25. Murcutt G: Buttonhole cannulation: Should this become the default technique for dialysis patients with native fistulas? Summary of the EDTNA/ERCA Journal Club discussion Autumn 2007. J Ren Care 34: 101–108, 2008. 26. Pipkin M, Craft V, Spencer M, Lockridge RS Jr: Six years of experience with nightly home hemodialysis access. Hemodial Int 8: 349–353, 2004. 27. van Loon MM, Kessels AG, Kessel AG, van der Sande FM, Tordoir JH: Cannulation practice patterns in haemodialysis vascular access: Predictors for unsuccessful cannulation. J Ren Care 35: 82–89, 2009. 28. Marticorena RM, Hunter J, Cook R, et al: A simple method to create buttonhole cannulation tracks in a busy hemodialysis unit. Hemodial Int 13: 316–321, 2009. 29. Toma S, Shinzato T, Fukui H, et al: A timesaving method to create a fixed puncture route for the buttonhole technique. Nephrol Dial Transplant 18: 2118–2121, 2003.
