Role of Preoperative Duplex Ultrasonography to Predict Functional Maturation of Wrist Radiocephalic Arteriovenous Fistula: A Study on Indian Population

International survey of radiocephalic arteriovenous fistula: ISRAF survey

AIMS

The objective of this survey was to encompass the full scope of international practice, entailing all technical, non-technical, preoperative stratification and functional maturation (FM) of RCAVF.

METHODS

The survey contained n = 19 questionnaires with n = 46 variables completed by n = 85 providers from n = 21 nations across n = 5 continents. The numerical values were subjected to mean with standard error whereas the nominal data to a non-parametric (Kruskal-Wallis & Spearman correlation test) and analysis of variance (ANOVA). The test of homogeneity, & probability was reported 95% confidence intervals (CI) alongside error plots. Furthermore, a decision and higher attribute tree model was constructed based on current survey for higher FM in RCAVF.

RESULTS

FM is independently associated with volume of surgeon per year (procedures performed) (p < 0.01) [High Volume: 73% (95% CI, 68-77%) versus Average volume: 63% (95% CI, 59-66%) vs Low volume: 56% (95% CI, 51-61%)]. FM increased by 8% with every 20 more procedures per group of surgeons on end point of FM. Amongst continents: Australia, America, Asia and South America demonstrated higher FM to Africa & Europe (p < 0.05). UK possessed a lower FM 58% (95% CI, 48-68%) in comparison to the world & Europe respectively [65% (95% CI, 61-70%) vs 61% (95% CI, 58--65%)]. There was a positive causal link between angle of anastomosis at 30-76° (p < 0.01), longitudinal & S-shaped incision & arteriotomy length of 3 & 4 mm to higher FM (p < 0.05).

CONCLUSION

FM in RCAVF is independently & incrementally associated with the volume of surgeon per year. There is a diverse inclusion, exclusion and technical approach in RCAVF creation. This survey advocates the importance of international collaboration and/or registry in assimilation, consolidate and development of consensus.

The Role of Ultrasound Examination in the Assessment of Suitability of Calcified Arteries for Vascular Access Creation-Mini Review

Arterial calcifications are present in 20-40% of patients with end-stage kidney disease and are more frequent among the elderly and diabetics. They reduce the possibility of arterio-venous fistula (AVF) formation and maturation and increase the likelihood of complications, especially distal ischemia. This review focuses on methods for detecting arterial calcifications and assessing the suitability of calcified arteries for providing inflow before the construction of an AVF. The importance of a clinical examination is stressed. A grading system is proposed for quantifying the severity of calcifications in the arteries of the arm with B-mode and Doppler ultrasound exams. Functional tests to assess the suitability of the artery to provide adequate inflow to the AVF are discussed, including Doppler indices (peak systolic velocity and resistive index during reactive hyperemia). Possible predictors of the development of distal ischemia are discussed (finger pressure, digital brachial index, acceleration and acceleration time), as well as the outcomes of AVFs placed on calcified arteries. It is concluded that a noninvasive ultrasound examination is probably the best tool for a morphologic and functional assessment of the arteries. An arterial assessment is of utmost importance if we are to create distal radiocephalic AVFs in our elderly patients whenever possible without burdening them with futile surgical attempts.

Patency Rates and Outcomes of Renal Access Arteriovenous Fistulas for Hemodialysis in Patients with Chronic Kidney Disease

Hemodialysis remains the most popular modality of renal replacement therapy for end-stage renal disease patients with chronic kidney disease. Various factors such as a radial artery, cephalic vein diameter, age, hypertension, and diabetes mellitus can affect the fistula maturation. This study was carried out to know the patency rates and factors affecting fistula maturation in the Indian population. This is a prospective observational study which aimed to study the patency rate of arteriovenous (AV) fistulas. On the day of surgery, patients were shifted inside the operation theater. Under all aseptic precautions, an AV fistula was formed using the radial artery and cephalic vein. All patients were followed up for 6 months. The data were analyzed using IBM SPSS version 22. To see the change over a period of time, McNemar test for categorical data and repeated measure for continuous data followed by post hoc comparison by Bonferroni method were used. The mean age of the patients was 46.98 ± 13.33 years. The mean diameter of the cephalic vein, ulnar artery, and radial artery at the wrist was 1.733 ± 0.528, 1.700 ± 0.364, and 1.908 ± 0.420, respectively, whereas the mean diameter of the cephalic vein, ulnar artery, and radial artery at the forearm was 1.952 ± 0.488, 1.910 ± 0.421, and 2.058 ± 0.458, respectively. Immediate thrill after the surgery was present in 36/52 (69.2%) of the patients. The radial artery diameter at the wrist was significantly less in the patients with primary failure in whom immediate thrill was not present (P = 0.016). At 1-month follow-up, 30/49 (61.2%) and, at 6 months, 29/48 (60.4%) fistulas were functional. Radiocephalic AV fistulas have a reasonable success rate and minimal morbidity, and radial artery diameter is a good predictor of the outcome.

Role of color Doppler assessment in predicting outcomes of wrist Brescia-Cimino arteriovenous fistula creation: A single-center prospective study

Introduction

The most common reason for constructing an arteriovenous fistula (AVF) is chronic kidney disease. Various factors are associated with nonmaturation or failure of AVF, which can be evaluated using color Doppler/duplex ultrasound (DUS). We carried out this study to evaluate the role of pre- and postoperative DUS for the prediction of outcomes of wrist radiocephalic (RC) AVF.

Methods

In our prospective observational study, dialysis-dependent patients between 20 and 70 years of age undergoing primary RC-AVF from May 2019 to July 2020 were included. All patients underwent pre- and postoperative DUS examination after obtaining consent.

Results

Among 104 participants, 87 (83.7%) were male and 17 (16.3%) were female. Successful maturation was seen in 68 (65.4%) participants, whereas 90 (86.53%) had functional maturation. Radial artery diameter (RAD) ≥1.6 mm, cephalic vein diameter (CVD) ≥2.0 mm, vein distensibility (VD) ≥0.5 mm, and peak systolic velocity (PSV) RAD ≥30 cm/s were associated with higher successful maturation of AVF with statistically significant results (P < 0.05). RAD ≥1.6 mm, CVD ≥2.0 mm, VD ≥0.5 mm, and PSV RAD ≥30 cm/s were related to a greater probability of RC-AVF maturation. Among them, VD and PSV-RA were the most influencing factors predicting RC-AVF successful maturation.

Conclusions

If we consider the rule of six for AVF maturation, then the results will be much less than the actual fistulas which are dialyzable with adequate blood flow as per functional maturation criteria. Thus, more randomized studies are needed to define maturation criteria for the Indian population and to identify the effect of papaverine on successful AVF maturation.

Venous distensibility is more important than venous diameter in primary survival of autogenous radiocephalic arteriovenous fistulas

BACKGROUND

Many studies suggested that the optimal cephalic vein diameter for wrist radio-cephalic arteriovenous fistula construction should be at least 2 mm to predict successful maturation and primary patency. However, our experience has shown that many patients with smaller cephalic vein diameter (≤2 mm) in the neutral state (without a tourniquet) also have good clinical outcomes. The aim of this study was to identify predictors that affect primary survival of new wrist radio-cephalic arteriovenous fistula in patients with cephalic vein diameter ≤2 mm.

METHODS

We performed a retrospective review of 50 patients with preoperative cephalic vein diameters ≤2 mm in the neutral state who underwent wrist radio-cephalic arteriovenous fistula construction between September 2016 and October 2019. Internal diameters of the cephalic vein and radial artery, venous distensibility, peak systolic velocity, and resistance index of the radial artery were determined by ultrasound examination before wrist radio-cephalic arteriovenous fistula placement. Patients were divided into two groups: failure and survival.

RESULTS

The radio-cephalic arteriovenous fistula survival rate was 68% from the time of radio-cephalic arteriovenous fistula creation until the end of the study. Univariate analysis showed that larger venous distensibility (p < 0.001), non-diabetic kidney disease (p = 0.009), and slower peak systolic velocity of the radial artery (p = 0.033) were predictive factors for primary radio-cephalic arteriovenous fistula survival. Multivariate regression analysis revealed good venous distensibility (odds ratio = 9.637, 95% confidence interval = 1.893-49.050, p = 0.006) and non-diabetic kidney disease (odds ratio = 0.148, 95% confidence interval = 0.033-0.660, p = 0.012) to be independent predictors for primary radio-cephalic arteriovenous fistula survival. Receiver operating characteristic analysis showed that venous distensibility >0.52 mm (sensitivity: 70.6%, specificity: 68.8%) was the best cut-off value to predict primary radio-cephalic arteriovenous fistula survival.

CONCLUSION

When cephalic veins with diameter ≤2 mm are found, venous distensibility should be used to aid in the surgery decision-making process. The outcome of wrist radio-cephalic arteriovenous fistula survival would be significantly improved through the use of cephalic vein with venous distensibility >0.52 mm.

Preoperative cephalic vein diameter and diabetes do not limit the choice of wrist radio-cephalic arteriovenous fistula

Aim:

To identify predictors that affect initial maturation of new wrist radio-cephalic arteriovenous fistula and evaluate the clinical effects of the ipsilateral mid-forearm radio-cephalic arteriovenous fistulas creation in the event of first wrist radio-cephalic arteriovenous fistula failure.

Methods:

We performed a retrospective review of all patients who underwent first wrist radio-cephalic arteriovenous fistula creation between September 2016 and May 2018. Currently, we prefer to re-create an ipsilateral mid-forearm radio-cephalic arteriovenous fistula when the first wrist radio-cephalic arteriovenous fistula fails. Predictors of successful radio-cephalic arteriovenous fistulas were identified using univariate and multivariate analyses. Kaplan–Meier survival analysis and log-rank test were used to calculate successful radio-cephalic arteriovenous fistula rates.

Results:

Univariate analysis showed that predictive factors for successful wrist radio-cephalic arteriovenous fistula include larger preoperative cephalic vein diameter ( p = 0.001) and non-diabetic kidney disease ( p = 0.007). Multivariate binary logistic regression analysis revealed cephalic vein diameter ⩾2 mm (odds ratio = 4.55, 95% confidence interval = (1.49–13.92), p = 0.008) and non-diabetic kidney disease (odds ratio = 4.22, 95% confidence interval = (1.38–12.88), p = 0.011) to be independent predictors for successful radio-cephalic arteriovenous fistula. We re-created ipsilateral mid-forearm radio-cephalic arteriovenous fistulas in 15 patients among the 21 failed wrist radio-cephalic arteriovenous fistulas; all these arteriovenous fistulas maintained clinical maturation following up for 1–2 years.

Conclusion:

Small cephalic vein diameter (<2 mm) and diabetes were independent risk factors for failed wrist radio-cephalic arteriovenous fistulas, but this risk could be overcome by aggressive ipsilateral mid-forearm radio-cephalic arteriovenous fistula to address a failed first attempt. Cephalic vein diameter is more important during the maturation stage, and once maturation has occurred, diabetes has an additive role in determining the patency of wrist radio-cephalic arteriovenous fistula. The “wrist RCAVF first, ipsilateral mid-forearm RCAVF second” strategy is the most clinically significant message of our study.