Nerve Conduction Study in the Extremity Carrying Fistula in Hemodialysis Patients

Arteriovenous fistulas (AVF) make chronic hemodialysis easy, but the complications are unpredictable. Ischemic neuropathy due to arterial insufficiency is one of the most important complications of AVF. This study was designed to evaluate ischemic neuropathy using electro diagnostic method in the extremity carrying fistula.

In this cross-sectional study, 37 hemodialysis patients at the hemodialysis center of Shahid-Mohammadi hospital (Bandar-Abbas) were enrolled. All of the patients had only one AVF in one extremity. NCV of median and ulnar nerves of both upper extremities were evaluated and the intact extremity of all patients served as the control group.

In patients with distal AVF, ulnar motor conduction velocities were significantly increased (p: 0.034). Distal and proximal amplitudes of ulnar nerve were decreased only in non-diabetic and hypertensive patients (p<0.05). Median sensory nerve action potential was increased, distal amplitude decreased (p: 0.04) and sensory latency was increased (p: 0.02). In patients with proximal AVF, ulnar proximal amplitude and median motor conduction velocities were decreased (p: 0.05). There was a negative correlation between the age of AVF and development of neuropathy. In most patients with neuropathy, AVF age was less than one year.

Ulnar nerve is more sensitive to ischemia than median nerve and sensory fibers are more sensitive than motor fibers. The site of fistula had no affect on the rate of development of ischemic neuropathy. We recommend using electrodiagnostic study for screening of ischemic neuropathy every 6 months in hemodialysis patients.