Chronic kidney disease (CKD) represents a growing global health burden, with increasing numbers of patients requiring renal replacement therapy in the form of hemodialysis [1]. Vascular access is a critical determinant of successful hemodialysis, and among the available options, autogenous arteriovenous fistula (AVF) is considered the gold standard due to its superior long-term patency and lower rates of infection and thrombosis compared to grafts and central venous catheters [2,3]. Despite its advantages, AVF maturation failure remains a significant concern, with reported primary failure rates ranging from 20% to 50% [4]. Maturation is defined as the ability of the fistula to provide adequate blood flow for dialysis, typically requiring vessel dilation and wall remodeling following surgical creation [5]. Several patient-related and procedure-related factors influence this process, including age, vascular quality, comorbid conditions such as diabetes mellitus, and the timing of AVF creation [6]. The location of the fistula also plays a pivotal role in determining maturation success. Radiocephalic AVFs, created at the wrist, are preferred as the first-line option due to preservation of proximal sites; however, they may have variable success depending on vessel caliber and quality [7]. In contrast, brachiocephalic AVFs offer higher flow rates but may be associated with higher complication rates [8]. Early referral and timely creation of AVF before the initiation of maintenance hemodialysis have been strongly advocated to improve outcomes. Delayed AVF creation often results in prolonged catheter dependence, increasing the risk of infection and central venous stenosis [9]. Furthermore, advancing age and vascular comorbidities have been shown to adversely affect vascular remodeling and fistula maturation [10]. Given these considerations, identifying the key determinants of AVF maturation is essential for optimizing patient outcomes. This study aims to evaluate the clinical and procedural factors influencing AVF maturation in a large cohort of hemodialysis patients in a single tertiary care center.

This prospective observational study was conducted at a tertiary vascular care center in Hyderabad over a period of 11 months in 2020. A total of 1500 patients with end-stage renal disease (ESRD) undergoing AVF creation for hemodialysis access were included. Ethical approval was obtained from the institutional review board, and informed consent was secured from all participants. Patients were evaluated preoperatively using clinical examination and Doppler ultrasonography to assess arterial and venous anatomy. Inclusion criteria comprised patients aged ≥18 years undergoing first-time AVF creation. Patients with previous vascular access surgery, severe peripheral arterial disease, or coagulopathies were excluded. AVFs were categorized based on anatomical location into radiocephalic and brachiocephalic fistulas. Timing of AVF creation was classified as early (before initiation of maintenance hemodialysis) and late (after initiation). Demographic variables such as age, sex, and comorbid conditions including diabetes mellitus and hypertension were recorded. AVF maturation was assessed at 6 weeks postoperatively using clinical parameters and Doppler evaluation. Successful maturation was defined as adequate blood flow (>600 mL/min), vein diameter ≥6 mm, and suitability for cannulation. Statistical analysis was performed using SPSS version 25. Continuous variables were expressed as mean ± standard deviation, and categorical variables as percentages. Associations between variables and AVF maturation were analyzed using Chi-square test and independent t-test. A p-value <0.05 was considered statistically significant.

Overall Findings Out of 1500 patients included in the study, successful AVF maturation was observed in 1239 cases, yielding an overall maturation rate of 82.6%. The mean age of the study population was 52.4 ± 13.6 years, with males constituting 62% of the cohort. Radiocephalic AVFs accounted for 58% of cases, while brachiocephalic AVFs comprised 42%. Early AVF creation was performed in 61% of patients. Younger age, early creation, and distal fistula location were significantly associated with improved maturation outcomes (p<0.001). Table 1 Table 1 demonstrates the distribution of AVF maturation based on age groups. Patients younger than 50 years showed a significantly higher maturation rate (86.5%) compared to those aged 50 years and above (76.2%). The difference was statistically significant (p<0.001), indicating that advancing age adversely affects vascular remodeling and fistula maturation. These findings are consistent with the known impact of age-related vascular stiffness and endothelial dysfunction on AVF outcomes. Table 1: Age vs AVF Maturation Age Group Total (n) Matured (n) Failed (n) Maturation Rate (%) <50 years 720 623 97 86.5 ≥50 years 780 616 164 76.2 Table 2 Table 2 compares maturation rates between radiocephalic and brachiocephalic AVFs. Radiocephalic AVFs demonstrated a higher maturation rate of 85.2% compared to 78.4% in brachiocephalic AVFs (p<0.001). This suggests that distal fistulas, when anatomically feasible, may offer better maturation outcomes. Preservation of proximal vessels and favorable hemodynamics likely contribute to improved results in radiocephalic AVFs. Table 2: Type of AVF vs Maturation AVF Type Total (n) Matured (n) Failed (n) Maturation Rate (%) Radiocephalic 870 741 129 85.2 Brachiocephalic 630 498 132 78.4 Table 3 Table 3 evaluates the impact of timing of AVF creation on maturation. Early AVF creation resulted in significantly higher maturation rates (88.1%) compared to late creation (74.3%) (p<0.001). Patients undergoing early fistula creation had better vascular adaptation and reduced exposure to catheter-related complications, emphasizing the importance of timely referral and pre-dialysis planning. Table 3: Timing of AVF Creation vs Maturation Timing Total (n) Matured (n) Failed (n) Maturation Rate (%) Early 915 806 109 88.1 Late 585 433 152 74.3 Table 4 Table 4 highlights the influence of diabetes mellitus on AVF maturation. Diabetic patients had a lower maturation rate (74.8%) compared to non-diabetics (86.9%) (p<0.001). This reflects the impact of microvascular disease, endothelial dysfunction, and impaired vascular remodeling associated with diabetes, contributing to higher rates of AVF failure. Table 4: Diabetes vs AVF Maturation Diabetes Status Total (n) Matured (n) Failed (n) Maturation Rate (%) Diabetic 620 464 156 74.8 Non-diabetic 880 775 105 86.9

The present study evaluated the determinants of AVF maturation in a large cohort of 1500 patients and demonstrated an overall maturation rate of 82.6%, which is comparable to previously reported rates in literature [11]. The findings reaffirm that multiple patient-related and procedural factors significantly influence AVF outcomes. Age emerged as a critical determinant, with younger patients exhibiting significantly better maturation rates compared to older individuals. This observation aligns with studies by Allon et al. and Lok et al., which reported reduced AVF success in elderly populations due to vascular calcification and reduced compliance [11,12]. Age-related endothelial dysfunction and arterial stiffness impair the adaptive remodeling necessary for fistula maturation. The type of AVF also played a significant role, with radiocephalic AVFs demonstrating superior maturation rates compared to brachiocephalic AVFs. Although proximal fistulas typically provide higher flow rates, distal fistulas preserve vascular anatomy and may offer better long-term outcomes when feasible [13]. Similar findings have been reported in the Dialysis Outcomes and Practice Patterns Study, emphasizing the benefits of distal access creation [14]. Timing of AVF creation was one of the most influential factors in this study. Early creation before the initiation of hemodialysis resulted in significantly higher maturation rates. This supports the “Fistula First” initiative, which advocates early planning and access creation to reduce catheter dependence and improve outcomes [15]. Delayed AVF creation often leads to prolonged catheter use, increasing the risk of infection and central venous complications. Diabetes mellitus was associated with significantly lower maturation rates, consistent with previous studies demonstrating the adverse impact of diabetes on vascular integrity [16]. Diabetic vasculopathy, characterized by intimal hyperplasia and endothelial dysfunction, contributes to increased rates of AVF failure. Other studies have also highlighted the importance of preoperative vessel mapping and surgical expertise in improving outcomes [17]. Adequate vessel diameter and flow dynamics are essential prerequisites for successful maturation. The strengths of this study include its large sample size and comprehensive evaluation of multiple variables. However, limitations include its single-center design and lack of long-term follow-up data on patency and complications. Overall, the study underscores the importance of early intervention, appropriate patient selection, and optimization of modifiable risk factors to enhance AVF maturation outcomes.

This study demonstrates that AVF maturation is influenced by multiple interrelated factors, including patient age, fistula type, timing of creation, and comorbid conditions such as diabetes mellitus. Radiocephalic AVFs showed superior maturation outcomes compared to brachiocephalic AVFs, supporting their preferential use when anatomically feasible. Early creation of AVF prior to initiation of maintenance hemodialysis significantly improves maturation rates and reduces failure. Younger patients exhibited better outcomes, highlighting the impact of vascular health on fistula success. These findings emphasize the need for early referral, careful preoperative assessment, and individualized planning of vascular access. Strategies aimed at optimizing patient condition and timely AVF creation can substantially improve hemodialysis outcomes and reduce complications associated with vascular access failure.

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