Back to 2025 Abstracts
Massive Aneurysmal Arteriovenous Fistulae And Challenges With Diagnostic Tools
Andrew Huang, MD, Justin Rodriguez, BA, Christopher Audu, MD PhD, Peter Henke, MD.
University of Michigan, Ann Arbor, MI, USA.
Demographics: Our patient is a 26 year old male with end stage renal disease on hemodialysis secondary to IgA nephropathy. He is a current 0.5 packs per day smoker. He had his initial dialysis created via a left brachiocephalic fistula at an outside hospital in November 2020.
History: Since his index fistula creation, he has required multiple interventions to maintain fistula patency due to high venous pressures and tortuosity. Interventions included multiple fistulograms, operative straightening of tortuosity, cephalic stenosis resection, and left infraclavicular first rib resection for possible venous thoracic outlet syndrome. He presented to our institution for management of a 53 mm tortuous, aneurysmal fistula (Figure 1A). He did not demonstrate skin changes, pain, or difficulty with dialysis access. An ultrasound demonstrated flow at 1.7-25.5 L/min (Figure 1B, 1C). The patient denied symptoms of heart failure with an ejection fraction of 65%.
Plan: Given the large aneurysm and concern for the future development of high output heart failure, we decided to proceed with surgical repair. We began with an incision overlying the aneurysmal fistula, carefully isolating the fistula and ligating branches to the axilla where it appeared non-aneurysmal (Figure 1D). Due to recurrent tortuosity despite surgical management, we decided to proceed with an interposition 6 mm PTFE Gore Acuseal graft instead of segmental resection or vessel plication (Figure 1E).
Discussion: Flow measurements in large, aneurysmal AVF should be taken with a dose of skepticism. The widely discordant ultrasound flow measurements in this case gave us pause, as a tube should have consistent flow along its course and no major collaterals were seen. Aneurysmal fistulae are prone to erroneous flow measurements. Flow is a function of velocity and vessel area, for which our ultrasound system assumes is a circle. Eccentric vessels (Figure 1B) can introduce significant error (12% in this case). Doppler angle can be a source of error in aneurysmal vessels, as true axis of blood flow can be challenging to ascertain. Error increases exponentially as the insonation angle increases past 60 degrees. Inadequately capturing vessel borders can artificially elevate flow by excluding the low flow borders of the artery.
Back to 2025 Abstracts
