The effect of early conversion from central venous catheter to arteriovenous fistula on hospitalization and mortality in incident haemodialysis patients

Effect of preoperative arterial diameter on hospitalization and mortality in patients undergoing hemodialysis with forearm arteriovenous fistula access

BACKGROUND

As pointed out by the recent Kidney Disease Outcomes Quality Initiative Clinical Practice Guideline for Vascular Access, the current quality of evidence supporting preoperative vascular anatomy and patient outcomes is suboptimal and insufficient to make recommendations. This study assessed arteriovenous fistulas (AVFs) created with different preoperative arterial diameters on hospitalization and mortality rates in patients undergoing hemodialysis at the authors' center.

METHODS

Data from 261 patients who underwent HD between 2017 and 2019 were retrospectively examined. Differences in mortality and hospitalization rates between patients with different preoperative arterial diameters were compared, and risk factors for mortality and hospitalization were analyzed.

RESULTS

Smaller preoperative artery diameter (<2 mm) was associated with all-cause mortality (risk ratio [RR] 1.61 [95% confidence interval (CI) 1.45-1.90]; p < 0.01), and access-related (RR 1.68 [95% CI 1.24-2.44]; p < 0.01), and congestive heart failure (CHF)-related (RR 0.67 [95% CI 0.38-1.01]; p = 0.04) hospitalization. Longer catheter-dependent duration (⩾60 days) was associated with access-related hospitalization (RR 1.48 [95% CI 1.07-2.11]; p = 0.03), and higher postoperative brachial artery blood flow (⩾1500 mL/min) was associated with CHF-related hospitalization (RR 1.58 [95% CI 1.02-2.29]; p < 0.01). Higher postoperative brachial artery blood flow (⩾1500 mL/min) was associated with all-cause mortality (hazard ratio [HR] 1.20 [95% CI 1.09-2.32]; p = 0.04), whereas preoperative artery diameter (HR 0.98 [95% CI 0.93-1.86]; p = 0.08) and catheter-dependent duration (HR 1.06 [95% CI 0.47-2.13]; p = 0.82) were not associated with all-cause mortality.

CONCLUSION

In this cohort, smaller preoperative artery diameter was associated with all-cause and access-related hospitalizations, while a larger preoperative artery and higher postoperative brachial blood flow were associated with CHF-related hospitalization. However, only higher postoperative brachial blood flow was associated with all-cause mortality.

Friction injury of the central vein caused by catheter for hemodialysis: an in vitro study

Vascular injury such as central venous stenosis (CVS) is a common complication in hemodialysis patients with central venous catheters (CVCs), yet the impact of the microstructure and partial physic characteristics of catheter surface on the chronic injury of central vein has not been elucidated. In this study, the microscopic morphology of tips and bodies of six different brands of polyurethane CVCs was observed and their roughness was assessed. Subsequently, an in vitro model was established to measure the coefficients of friction (COF) between CVCs (tips and bodies) and the vena cava intima of Japanese rabbits under the same condition in a linear reciprocating mode, and changes in the intima of vessels after friction were observed. The study found that there was a significant variation in surface roughness among different brands of CVCs (tips P < 0.001, bodies P = 0.02), and the COF was positively correlated with the catheter surface roughness (tips P = 0.005, R = 0.945, bodies P = 0.01, R = 0.909). Besides, the endovascular roughness increased after friction. These findings suggest that the high roughness surface of CVCs may cause chronic mechanical friction injury to the central venous intima, which is one of the potential factors leading to CVS or occlusion. This provides a breakthrough for reducing complications, improving patient prognosis, and advancing catheter surface lubrication technology.