Considerations in Access Cannulation: Traditional and Evolving Approaches

3D printed hemodialysis access and subcutaneous volume model as a guide for cannulation: A proof of concept training tool

A 54-year-old underwent brachiocephalic arteriovenous fistula placement. Following maturation of the access, consistent cannulation for routine hemodialysis was challenging for clinical specialists. A three-dimensional intraluminal access model was generated, but clinical specialists adept at cannulation had difficulty orienting the model to the patient's anatomy without repeat supervision. When provided the model prima facie, 50% (4/8) clinical specialists were not able to spatially orient the model appropriately in the x-axis with respect to the coronal plane (2/8) or in the z-axis with respect to the transverse plane (2/8). Spatial renderings of the subcutaneous volume available for cannulation were then printed and physically applied to the vascular access model resulting in appropriate spatial orientation among all clinical specialists (n = 12) that were presented the models for the first time. Mean Kt/V increased during the 3-month period directly following model introduction. This case demonstrates the potential utility of 3D-modeling to readily visualize the subcutaneous volume of a hemodialysis vascular access and reduce cannulation error.

Skin pigmentation as landmark for arteriovenous fistula cannulation in hemodialysis

BACKGROUND

The cannulation of the arteriovenous fistula (AVF) for hemodialysis (HD) has traditionally depended on the nurse's tactile sensation, which has been associated with suboptimal needle placement and detrimental effects on vascular access (VA) longevity. While the introduction of ultrasound (US) has proven beneficial in mapping the AVF outflow vein and assisting in cannulation planning, aneurysmal deformations remain a common occurrence resulting from various factors, including inadequate cannulation techniques. Within this context, the utilization of skin pigmentation as a clinical landmark has emerged as a potential approach to enhance cannulation planning in HD.

METHODS

A prospective longitudinal study was undertaken to investigate the correlation between the occurrence of venous morphological deformations and the cannulation technique guided by skin pigmentation after a 2-month period of implementation.

RESULTS

Thirty patients were enrolled in the study with 433 cannulations being described within the first 2 months of AVF use. The overall rate of cannulation-related adverse events was 21.9%. Comparative analysis demonstrated a statistically significant relationship (p < 0.001) between aneurysmal deformation and non-compliance with the proposed cannulation technique, resulting in cannulation outside the designated points. Non-compliance was primarily attributed to nurse's decision (57.1%).

CONCLUSION

The integration of US mapping of the AVF outflow vein and the utilization of skin pigmentation as a guiding tool have shown promising results in enhancing cannulation planning over time. Consistent adherence to a cannulation technique other than the area technique has been found to reduce the risk of AVF morphological deformation. These findings underscore the potential benefits of incorporating skin pigmentation as a clinical landmark in cannulation practices, highlighting its ability to impact positively cannulation outcomes.

Ultrasound-Guided Dynamic Needle-Tip Positioning Method Is Superior to Conventional Palpation and Ultrasound Method in Arterial Catheterization

Background: Dynamic needle-tip positioning (DNTP) was shown to improve arterial cannulation efficiency with fewer complications than conventional palpation and ultrasound methods by some studies. However, this is still controversial, and we performed this meta-analysis to comprehensively assess its value in arterial cannulation. Methods: A literature search of randomized controlled trials was conducted, and 11 studies were finally included. Efficiency outcomes (first-attempt success, overall success, and total cannulation time) and complications (hematoma, thrombosis, posterior wall puncture, and vasospasm) were separately analyzed. Subgroup analyses in different populations under cannulation were also performed. Results: DNTP was associated with increased first-attempt success (pooled RR = 1.792, p < 0.001), overall success (pooled RR = 1.368, p = 0.001), and decreased cannulation time (pooled SMD = −1.758, p = 0.001) than palpation. DNTP gained even more advantage in small children and infants. No significant difference in these outcomes between DNTP and conventional ultrasound method was detected. Fewer hematoma occurred in DNTP than palpation (pooled RR = 0.265, p < 0.001) or traditional ultrasound (pooled RR = 0.348, p < 0.001). DNPT was also associated with fewer posterior wall punctures (pooled RR = 0.495, p = 0.001) and vasospasm (pooled RR = 0.267, p = 0.007) than traditional ultrasound. Conclusions: DNTP was a better choice in artery cannulation than conventional palpation and ultrasound method, especially in small children and infants.

A narrative systematic review of randomised controlled trials that compare cannulation techniques for haemodialysis

BACKGROUND

Cannulation of arteriovenous access for haemodialysis affects longevity of the access, associates with complications and affects patients' experiences of haemodialysis. Buttonhole and rope ladder techniques were developed to reduce complications. However, studies that compare these two techniques report disparate results. This systematic review performs an in-depth exploration of RCTs, with a specific focus on cannulation as a complex intervention.

METHODS

A PICO question and protocol was developed as per PRISMA-P guidance and registered on PROSPERO (CRD42018094656 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=112895). The systematic review included any RCT performed on adult patients with end-stage kidney disease undergoing cannulation of arteriovenous fistulae or grafts for in-centre haemodialysis, as performed by healthcare staff. Assessment of quality of RCTs and data extraction were performed by two co-authors independently. Data were extracted on the study design, intervention and comparator and outcomes, including patency, infection and patients' experiences.

RESULTS

The literature search identified 241 records. Ten records met inclusion criteria, which described five different RCTs that compared buttonhole to either rope ladder or usual practice. Results were disparate, with patency and infection results varying. Pain Visual Analogue scores were the only measure used to capture patients' experiences and results were inconclusive. All RCTs had differences and limitations in study design that could explain the disparity in results.

CONCLUSION

Current evidence does not allow definitive conclusions as to whether buttonhole or rope ladder needling technique is superior. Future RCTs should describe interventions and comparators with adequate detail, embed process evaluation, use standardised outcome measures and build on feasibility studies to produce definitive results.