Update on Cannulation Techniques

There are two methods of fistula cannulation for hemodialysis. The first, different site or rope-ladder cannulation method, established by originators of the arteriovenous fistula as a blood access for hemodialysis in 1966, relies on changing the puncture sites for each dialysis. The second, constant site or buttonhole method, developed several years later, recommends using the same puncture sites for consecutive dialyses. The first method is prevailing at present, but the second method is becoming more and more popular. The major advantage of this buttonhole method is lower cannulation pain, fewer fistula complications, with the exception of fistula infection, which is more common in some studies. This method is more difficult and requires experienced single cannulator to establish good puncture sites. Home hemodialysis patients using single cannulator, the patient or helper, have better results with this method. Busy dialysis centers with high rotation of cannulators do not have as good results and prefer the rope-ladder method.

Arterio-venous fistula buttonhole cannulation technique: a retrospective analysis of infectious complications

BACKGROUND

There are two main methods of accessing arterio-venous fistulas (AVFs); the 'buttonhole' and the 'rope-ladder' cannulation technique. Several small studies have hypothesized that the buttonhole technique is associated with increased rates of fistula-associated infection. This study addresses this hypothesis.

METHODS

A retrospective review of all patients attending a large outpatient haemodialysis clinic was performed. Data were collected on the method of cannulation, infection rates, implicated microorganisms, complications of infection and time on haemodialysis.

RESULTS

A total of 127 patients had received haemodialysis via an AVF: 53 via the rope-ladder technique and 74 via the buttonhole technique. Nine episodes of clinically significant bacteraemia were recorded in the buttonhole group. This equated to a rate of 0.073 bacteraemia events per 1000 AVF days. There were no episodes of bacteraemia in the rope-ladder group. Eight infections were due to methicillin-sensitive Staphylococcus aureus (MSSA); one was due to Staphylococcus epidermidis. Three patients with MSSA bacteraemia subsequently developed infective endocarditis. Five patients who developed bacteraemia events had been undergoing home haemodialysis.

CONCLUSIONS

This study highlights the infectious complications associated with buttonhole cannulation techniques. All organisms isolated in our cohort were known skin colonizers. The reason for the increased rates of infection is unclear. Given this high rate of often life-threatening infection, we recommend regular audit of infection rates. We currently do not recommend this technique to our patients receiving haemodialysis.