Repeated Endovascular Interventions Are Worthwhile, Even After Thrombosis, to Maintain Long-Term Use of Autogenous Dialysis Fistulas

Comparing post-maturation outcomes of arteriovenous grafts and fistulae

BACKGROUND

Though arteriovenous grafts (AVG) mature more reliably than arteriovenous fistulae (AVF) and require fewer maturation procedures (MP) to obtain functional patency, AVG are thought to have worse function after maturation. We explored differences in post-maturation outcomes between the following groups: AVF patients who did (AS-AVF) and did not (unAS-AVF) require assisted maturation and AVG patients who did (AS-AVG) and did not (unAS-AVG) require assisted maturation.

METHODS

Using the US Renal Data System (2012-2017), we retrospectively identified patients who initiated dialysis with a central venous catheter, underwent AVF or AVG placement and achieved successful two-needle cannulation. Primary patency and access abandonment after maturation were compared across groups using competing risks regression methods, generating sub-hazards ratios (sHR).

RESULTS

We identified 42,664 AVF and 12,335 AVG that met inclusion criteria. A larger proportion of AVFs required interventions: 18,408 AVF (43.2%) versus 2594 AVG (21.0%; p < 0.01). Both AS-AVG and AS-AVF patients experienced patency loss at 1 year more frequently compared with unAS-AVG (67.5% & 57.5% vs 55.2% respectively). Patency loss was lowest in unAS-AVF (38.9%). These trends were robust on adjusted analysis (unAS-AVG reference, AS-AVG sHR = 1.44, p < 0.01; AS-AVF sHR = 1.08, p < 0.01, unAS-AVF sHR = 0.67, p < 0.01). AS-AVGs were more likely to be abandoned than unAS-AVGs (11.7% unAS-AVG vs 17.2% AS-AVG). Fistulae, assisted or not, had lower unadjusted rates of 1-year abandonment than grafts (8.9% AS-AVF vs 7.3% unAS-AVF). On adjusted analysis, AVF usage was protective against abandonment (unAS-AVG, reference; AS-AVF sHR = 0.67, p < 0.01; unAS-AVF sHR = 0.59, p < 0.01) while AS-AVG was not (AS-AVG sHR = 1.32, p < 0.01).

CONCLUSIONS

unAS-AVF have the best long-term outcomes. AS-AVF lose primary patency at a higher rate than unAS-AVG. AVGs may be a better choice than AVFs if veins are marginal and likely to require assisted maturation. Further research is needed to identify anatomic and physiologic factors that affect long-term performance and influence conduit choice.

A Retrospective Case-Control Study on Late Failure of Arteriovenous Fistula in Hemodialysis Patients and Prediction of Risk Factors

Objective

A retrospective case-control study was conducted to explore the risk factors of late failure of arteriovenous fistula in hemodialysis patients.

Methods

A total of 95 hemodialysis patients treated in our hospital from January 2018 to January 2021 were included. The HE staining results of late failure of arteriovenous fistula in hemodialysis patients were observed. The general data and laboratory indexes of the patients were recorded by using a questionnaire survey, hospital case system, and hemodialysis record. According to the functional status of internal fistula, the patients were divided into two groups: failure group (n = 35) and patency group (n = 60). SPSS22.0 software was employed for statistical analysis, and the relevant data of the two groups were compared. The independent sample t-test was employed for the comparison of variance between groups, and the χ 2 test was employed for counting data. Logistic multivariate regression was employed to analyze the risk factors of late loss of power in autologous arteriovenous fistula (AVF).

Results

(1) Late failure of arteriovenous fistula in hemodialysis patients: the results of HE staining showed the following: (1) histological changes of venous intima: 100% of the patients had varying degrees of intimal hyperplasia, mainly eccentric hyperplasia, resulting in luminal stenosis, and annular uniform intimal hyperplasia in some patients, and (2) histological changes of venous media: 81.6% of the patients had venous media lesions, which were mainly in two cases; one was media smooth muscle hyperplasia with fibrous tissue hyperplasia, and the other was smooth muscle compression when intimal hyperplasia was serious, resulting in smooth muscle fiber rupture, disarrangement, focal necrosis, atrophy, and thinning, and some smooth muscle stroma showed vitreous degeneration and myxoid degeneration. A few cases showed multifocal neutrophil, lymphocyte, and plasma cell infiltration. (2) First of all, we surveyed the general data, and there were significant differences in age, history of diabetes, history of hypertension, and uric acid nephropathy (P < 0.05). There was no significant difference in sex, body mass index, smoking history, polycystic kidney disease, chronic glomerulonephritis, and obstructive nephropathy between the two groups (P > 0.05). Secondly, we compared the levels of hemoglobin, eosinophils, platelet count, and hematocrit. The levels of hemoglobin, eosinophils, and hematocrit in the failure group were higher, and the platelet count was lower compared to that of the unobstructed group (P < 0.05). Furthermore, the calcium and phosphorus product and the level of C-reactive protein (CRP) in the failure group were higher, while the levels of fibrinogen and INR in the unobstructed group were lower. The levels of plasma protein, alkaline phosphatase, and cholesterol were higher in the failure group, while the level of triglyceride was lower in the failure group (P < 0.05). Finally, logistic regression analysis showed that age, hemoglobin, hematocrit, and calcium-phosphorus product were the risk factors for late failure of arteriovenous fistula in hemodialysis patients (P < 0.05). There exhibited no significant correlation between diabetes, hypertension, uric acid nephropathy, eosinophil, CRP, fibrinogen, INR, plasma protein, alkaline phosphatase, cholesterol, triglyceride, and late failure of arteriovenous fistula in hemodialysis patients.

Conclusion

Age, hemoglobin, hematocrit, and calcium-phosphorus product are independent risk factors for late failure of arteriovenous fistula in hemodialysis patients. The hemoglobin, eosinophil, platelet count, and hematocele in hemodialysis patients with late failure of arteriovenous fistula were higher. The indexes related to biochemistry, blood coagulation, and nutrition were significantly different from those without late failure of arteriovenous fistula. Thus, the risk of late failure of arteriovenous fistula can be predicted.