Find the full CMO Initiative series

Three years ago, the chief medical officers from 13 dialysis providers met to share common issues about patient outcomes, both successes and area for improvement. A commitment to share clinical and facility level approaches to issues, protocols and policies, even data, grew out of this initial meeting. Since that time there have been two national meetings attended by the CMOs and their operational teams and enormous collaboration to improve patient satisfaction and quality of dialysis. With almost monthly calls, including separate calls by operations teams, these CMOs are making strides to enhance the experience of the patient undergoing dialytic therapy.

This is not about the business of the dialysis provider. It is about the quality of patient care.

There is a commitment to address issues such as the catheter rate, hospitalizations and rehospitalizations, the quality of the intradialytic experience, infection prevention, morbidity and mortality, and which quality measures and processes really make a difference in the welfare of patients.

Additionally, the CMO group has had several meetings with various agencies within the Centers for Medicare & Medicaid Services and has acted as a resource to the Kidney Care Council and Kidney Care Partners. But the primary purpose has been to have an informal collaboration among colleagues who have agreed that acting together can have a unique impact on patient outcomes.

The NN&I series

In 2013, NN&I published a series of papers prepared by the CMOs on topics ranging from nutrition to sodium modeling to moving more patients to home dialysis therapies. The series continues this month with a review by the CMO group of the buttonhole technique for vascular access. We will cover two more topics in the February and March issues of NN&I––he optimal use of antibiotics and physician participation in infection control––representing agreements by the undersigned CMOs and their providers to address change that will impact key clinical conditions of patients within their respective dialysis facilities.

We believe that we cannot always wait for an evidence-based process to act on important issues. When the preponderance of evidence suggests that action must be taken, then we are prepared to respond.

Working together, we believe that we can make a change in our patients’ dialysis experience and, most importantly, their survival.


Tom Parker III, MD

The role of buttonhole cannulation

Buttonhole (BH) cannulation technique, also known as constant-site cannulation, involves the insertion of dialysis needles at the same spot, angle, and depth when initiating a treatment. It has been variably recommended over rope-ladder (RL) cannulation as a preferred means of fistula cannulation. It has been perceived to be associated with decreased pain, easier cannulation, faster hemostasis, and a lower incidence of hematoma and aneurysm formation.

A growing body of evidence, however, suggests that the problems offset the advantages. It is the consensus of the CMOs that, even for home dialysis, BH should be discouraged and patients should be very aware of the increased morbidity.

What we know

The most comprehensive literature review to date comparing BH and RL cannulation was published by Wong et al. 1 Out of over 1,000 citations referencing BH in the literature, this paper identified 23 studies of adult dialysis patients using BH cannulation that compared clinically meaningful outcomes with a RL control group. Five studies were randomized controlled trials and 18 were observational. Outcome measures compared between the two techniques included cannulation pain, incidence of infection, need for access intervention, access survival, time to achieve hemostasis, and incidence of hematoma and aneurysm formation. Most studies (17 of 23) were restricted to in-center patients, involved single dialysis units, and were relatively small in sample size (range, n=14-447) with short median or mean follow-up (< 14 months in 15 of 23 studies).

The review highlighted a consistent finding in the literature of increased infection associated with BH use. Of the ten available studies, four of which are randomized controlled trials, all reported an increase in infectious complications associated with BH cannulation, with rates up to 3-fold higher. 2  Most infections were Staphylococcus aureus bacteremia, with complications including endocarditis, discitis, septic arthritis, septic emboli and death. Suggested variables that may affect rates of BH infections include local site care, scab removal techniques, sterile cannulation technique, as well as the use of antibiotic cream at the BH site to reduce infection. 3 There is some evidence that strict attention to proper technique, or the use of mupirocin prophylaxis, may reduce the risk of infection. 4

The review also made clear the absence of apparent benefit of BH cannulation with respect to other clinical outcomes, including cannulation pain. This was compared in 14 studies, and there was no consistent trend towards pain reduction with either cannulation technique. Of the 9 observational studies that compared pain between the cannulation techniques, 4 studies reported a decrease in pain associated with BH use, 4 found no difference, and one study reported an increase in pain with BH cannulation. Of the five randomized controlled trials that compared cannulation pain, three found no difference, one reported an increase in pain and only one a decrease in pain with BH use. Study limitations included incomplete reporting of the use of local anesthesia prior to needle placement.

Does the buttonhole extend the life of the access?

Additionally, BH cannulation does not offer any clear advantage over RL cannulation with respect to need for access intervention, access survival, or hemostasis. Seven studies evaluated the association between need for access intervention and cannulation technique. Five studies found no difference. The two studies that found benefit were confounded by a more favorable access history at baseline in the BH group, or by a comparison RL group from a different dialysis unit. Similarly, there is no clear difference in access survival afforded by BH cannulation, and the only study that has shown benefit again had a more favorable access history at baseline in the BH group.

Finally, BH cannulation does not consistently improve hemostasis time. Time to achieve hemostasis was improved with the BH approach in four of five observational studies, but not different in the four randomized controlled trials that looked at this endpoint. In one randomized controlled trial, the time to achieve hemostasis was longer with the BH technique. 5 In favor of the BH cannulation is a reported decrease risk of aneurysm. 1



1.         Wong, B. et al. Buttonhole versus rope-ladder cannulation of arteriovenous fistulas for hemodialysis: A systematic review. Am J Kidney Dis, 2014.

2.         Muir, CA, et al. Buttonhole cannulation and clinical outcomes in a home hemodialysis cohort and systematic review. Clin J Am Soc Nephrol, 2014. 9 (1): p. 110-9.

3.         Moist, LM, Nesrallah GE. Should buttonhole cannulation be discontinued? Clin J Am Soc Nephrol, 2014. 9(1): p. 3-5.

4.         Labriola L. et al. Infectious complications following conversion to buttonhole cannulation of native arteriovenous fistulas: a quality improvement report. Am J Kidney Dis, 57(3): p. 442-8, 2011.

5.         Chan MR, et al. The effect of buttonhole cannulation vs. rope-ladder technique on hemodialysis access patency. Semin Dial, 27(2): p. 210-6, 2014.