To BAM or not to BAM?: A closer look at balloon-assisted maturation.

Background: Balloon assisted maturation (BAM) is a recent, innovative, yet controversial method for developing autogenous arterio-venous fistulae (AVF), with little supportive data. Few retrospective studies have addressed the efficacy of BAM and cofactors affecting successful maturation. We conducted a retrospective analysis of our vascular access database to compare possible factors associated with a successful BAM, as determined by increase in volume flow of the fistulae.

Methods: Between 2009 and 2010, data was prospectively collected on patients undergoing BAM of their AVF under ultrasound guidance at our institution. 30 of these patients, consisting of 143 BAMs, were retrospectively analyzed. Data collection included: past medical history, age, number of BAM procedures preformed, volume flow measurement (VFM) in mid-fistulae, size of balloon used, and presence of post procedural wall hematoma. VFM was determined with duplex within one month prior to and subsequent to each BAM performed.

Results: Of the 30 patients, consisting of 143 BAMs, the average age was 69 years old + 15 (range 38-92) with 20 males and 10 females. The most common risk factors were hypertension (n = 27) and diabetes mellitus (n = 16). The average BAM per patient was 4.8 (range 1-7). Of the 143 BAM procedures, 4 were excluded due to absence of preoperative or postoperative duplex. In 139 BAMs, 74 developed a post procedural hematoma as observed on duplex, and 76 showed an increase in VFM. In all BAMs analyzed, there was no correlation observed between the presence of a hematoma and increase in VFM (P = 0.87). Hematomas occurred most frequently during the second BAM procedure, with 24.3% of all hematomas observed. In 139 BAMs, 8 different balloon sizes were used, 3 mm-10 mm, with the 7mm balloon being the most frequently used (n = 34). No significant difference was noted between increase in VFM in 3 mm to 7 mm balloons. A 8 mm balloon was used in 31 BAMs with 22 developing hematomas. Of the 8mm balloon group, a statistical difference was noted between percent increase in VFM with presence of a hematoma and percent increase in VFM without presence of a hematoma (P = 0.027).

Conclusions: These preliminary data, suggest that a more aggressive approach to BAM, with use of larger balloons to create hematoma formation and minimizing excessive dilatation procedures, may have a significant impact on performing a successful maturation in respects to increase in VFM.