Abstract
Background and Aims: Background Arterio-venous fistulae (AVF) are the primary access in considerable number of patients on hemodialysis or approaching hemodialysis. A distally created AVF are preferred over proximal approach, as recommended by the guidelines. Non maturation of AVF fistulae remains a major caveat as compared to arteriovenous grafts. A consensus definition of non-maturation is not well defined; however characteristics of non-maturation include inadequate blood flow. Female gender and forearm location have been identified by previous analysis as predisposing factors for non-maturation. Patients with radiocepalic arterio-venous fistula experience the highest rate of non-maturation rates. One important cause of failed AVF maturation is the presence of collateral or veins or tributaries; this may or may not be associated with stenosis. These tributaries may reduce blood in the primary outflow vein, consequently, leading to delayed maturation of the AVF. Options to overcome this problem include coiling or embolization of the collaterals with variable success rate.
Aim To examine the efficacy of a novel non-invasive technique to manage maturation failure in radio- cephalic arteriovenous fistulae, through ultrasound guided compression obliteration of the collaterals (accessory cephalic) as identified cause of maturation failure to augment flow in the primary cephalic vein.
Method The application of this maneuver to patients according to selected criteria was approved by the institutional Ethical Review Board.
Patients’ selection
Non maturation was defined by the Rule of Sixes criteria by endorsed by as follows
Flow in the fistula should be greater than 600 mL/min, 6 mm caliber, not more than 6 mm depth, discernible margins and ready for use within six weeks
Assessing non-maturation in absence of stenosis
Ultrasound and Doppler evaluation of main cephalic and accessory cephalic veins to confirm insufficient flow volume at main cephalic vein used in radio-cephalic AVF due to distributed flow to one or more accessory cephalic veins missed by vascular surgeons during surgical radiocephalic AVF creation. To be eligible for this technique, a downstream stenosis should be ruled out by ultrasound, as in such case angioplasty will offer the ideal treatment.
13 patients with failing to mature AVF were consented to this technique. The consent stated that the techniques is totally non-invasive and that, in case of failure of the technique, an endovascular management by coiling for example or a vascular surgical opinion will be sought without delay.
Technique summary: using high frequency probe linear ultrasound to perform long term compression for at least 20 minutes in short axis view over the accessory cephalic vein to obtain complete thrombosis and then examine the main cephalic vein to measure post procedure improving flow volume rate
Results
Patients’ characteristics
13 patients underwent the procedure. Baseline characteristics are shown below:
The technique was successful in 9 (5 males and 4 females) out of 13 patients
Not referred to interventional radiologist or vascular surgeons
Baseline patient’s characteristics
Age(years)Means63±9
SexMale5Female8
Conclusion
The novel technique as described may provide a safe non-invasive solution to patient with failing to mature radiocephalic arteriovenous fistula and may be referred for a trial of noninvasive ultrasound guided accessory cephalic vein compression obliteration to avoid invasive interventional radiology techniques or surgical repair.
A surgical option remains the ultimate solution in case of failure of this ultrasound guided maneuver.
