Buttonhole cannulation and clinical outcomes in a home hemodialysis cohort and systematic review

Abstract

Background and objectives: The relative merits of buttonhole (or blunt needle) versus rope ladder (or sharp needle) cannulation for hemodialysis vascular access are unclear.

Design, setting, participants, & measurements: Clinical outcomes by cannulation method were reviewed in 90 consecutive home hemodialysis patients. Initially, patients were trained in rope ladder cannulation. From 2004 on, all incident patients were started on buttonhole cannulation, and prevalent patients were converted to this cannulation method. Coprimary outcomes were arteriovenous fistula-attributable systemic infections and a composite of arteriovenous fistula loss or requirement for surgical intervention. Secondary outcomes were total arteriovenous fistula-related infections and staff time requirements. Additionally, a systematic review evaluating infections by cannulation method was performed.

Results: Seventeen systemic arteriovenous fistula-attributable infections were documented in 90 patients who were followed for 3765 arteriovenous fistula-months. Compared with rope ladder, buttonhole was not associated with a significantly higher rate of systemic arteriovenous fistula-attributable infections (incidence rate ratio, 2.71; 95% confidence interval, 0.66 to 11.09; P=0.17). However, use of buttonhole was associated with a significantly higher rate of total arteriovenous fistula infections (incidence rate ratio, 3.85; 95% confidence interval, 1.66 to 12.77; P=0.03). Initial and ongoing staff time requirements were significantly higher with buttonhole cannulation. Arteriovenous fistula loss or requirement for surgical intervention was not different between cannulation methods. A systematic review found increased arteriovenous fistula-related infections with buttonhole compared with rope ladder in four randomized trials (relative risk, 3.34; 95% confidence interval, 0.91 to 12.20), seven observational studies comparing before with after changes (relative risk, 3.15; 95% confidence interval, 1.90 to 5.21), and three observational studies comparing units with different cannulation methods (relative risk, 3.27; 95% confidence interval, 1.44 to 7.43).

Conclusion: Buttonhole cannulation was associated with higher rates of infectious events, increased staff support requirements, and no reduction in surgical arteriovenous fistula interventions compared with rope ladder in home hemodialysis patients. A systematic review of the published literature found that buttonhole is associated with higher risk of arteriovenous fistula-related infections.

Figure 1.

Rate of AVF-attributable infections per 1000 AVF-days by cannulation technique in a single home hemodialysis unit. The lines represent the 95% confidence intervals around the infection rate. *Significant difference in total infection rate between the BH and RL techniques (P≤0.05). AVF, arteriovenous fistula; BH, buttonhole; RL, rope ladder.

Figure 2.

Initial training time and overall service requirements by cannulation technique in a single home hemodialysis unit. (A) Length of initial home training (days) by cannulation technique in a single home hemodialysis unit. The error bars indicate the interquartile range in days (P<0.01). (B) Ongoing support requirements (in encounters [including training, home visits, and dialysis sessions in the home training center] per 1000 AVF-days) by cannulation technique in a single home hemodialysis unit (P<0.01). AVF, arteriovenous fistula.

Figure 3.

Forest plot of systematic review for total arteriovenous fistula-attributable infections.^∼We used reported odds ratios and relative risks when reported. ^{^}We compared period 1 (rope ladder cannulation only) with period 4 (buttonhole cannulation only after the education session). ^%This study did not report the numbers of patients but only the number of occasions that the arteriovenous fistula was accessed. 95% CI, 95% confidence interval; RR, relative risk.