The impact of pre-existing radial artery pathology by histological assessment on the maturation, function and patency of the radiocephalic fistula for hemodialysis.

BACKGROUND: We prospectively analyzed the effect of preexisting structural changes of the radial artery (RA) wall by histological examination on the wrist radiocephalic fistula (RCF) outcomes. METHODS: During RCF creation, one segment of the RA wall was collected and its histomorphometric analysis was performed. The RCF function was evaluated by measuring blood flow rate. RESULTS: At the end of follow-up, 75.7% of the thirty-seven patients enrolled were performing hemodialysis by using their successful RCF and 24.3% of them showed early RCF failure. Compared to patients with a healthy RA, the RCF of those with medial RA microcalcification reached up a lower flow and a shorter primary patency (P=0.005 and P=0.040, respectively). The RA microcalcification was predictive of the RCF function (coefficient -614.9, 95% CI: -994.7 to -235.1, P=0.003). Compared to patients with successful RCF, those with failed RCF had a greater frequency of weak RCF thrill after releasing the clamps (P=0.045). Dependence on hemodialysis during RCF placement was predictive of its early failure (OR: 23.2, 95% CI: 1.76 to 306.9, P=0.017). Both having at least one cardiovascular comorbidity (HR 4.30, 95% CI: 1.29 to 14.39, P=0.018) and a thicker media layer of the RA (HR 1.60, 95% CI: 1.87 to 2.15, P=0.002) were predictive of primary RCF patency. CONCLUSIONS: The function and survival of the successful RCF were related to preoperative RA abnormalities such as microcalcification and media layer thickness. Both dependence on hemodialysis during RCF placement and an attenuated RCF thrill were associated with early RCF failure.

Five years of vascular access stenosis surveillance by blood flow rate measurements during hemodialysis using the Delta-H method.

PURPOSE: To report experience over five years of vascular access (VA) stenosis surveillance. METHODS: We prospectively monitored the blood flow rate (QA) of 145 VA in 131 ESRD (age 62.6 ±13.5 y) patients (pts). QA measurement: within the first hour of the hemodialysis (HD) session by the Delta-H method using the Crit Line III Monitor. All VA with baseline QA < 700 mL/min or decreased > 20% from baseline over time met the positive evaluation (PE) criteria and were referred for angiography (AG) plus elective intervention if stenosis = 50%. RESULTS: We found 54 cases of PE in 47 VA; the AG was performed in 87% (47/54) cases of PE and most of them (43/47, positive predictive value: 91.5%) showed significant stenosis (mean degree 80.5 ±12.9%). Mean QA increased from 554.7±107.6 mL/min to 977.9 ± 359.9 mL/min just before versus after preventive intervention (P<.001). Without difference when comparing the highest QA reported before stenosis development (889.8 ± 409.5 mL/min) and the QA recorded just post-intervention (P=.18). Kt/V index: improved from 1.43 ± 0.22 to 1.49 ± 0.21 just before versus after intervention (P=.006). CONCLUSIONS: 1) The Delta-H technique is an accurate method for early diagnosis of VA stenosis and is useful in monitoring the hemodynamic effect of elective VA treatment. 2) After preventive intervention for stenosis, functional VA status is restored and HD delivery is improved.