Significance of Blunted Venous Waveforms Seen on Upper Extremity Ultrasound.

BACKGROUND

Current guidelines recommend vascular mapping ultrasound (US) prior to arteriovenous fistula creation. Blunted venous waveforms (BVWs) suggest central venous stenosis; however, this relationship and one between BVWs and the presence of a central venous catheter (CVC) remain unclear.

METHODS

All patients who received upper extremity vascular mapping US between January 2013 and October 2014 at a single institution were retrospectively reviewed. Patient demographics, comorbidities, US results, pacemaker history, and CVC status were collected. Waveforms were assessed at the proximal subclavian vein/distal axillary vein and interpreted by radiologists. Patients were determined to have central venous stenosis (CVS) if detected by venography within 6 months of US.

RESULTS

There were 342 patients, of which 165 (48%) had a current CVC and 29 (8.5%) had BVW of at least 1 arm. Right-sided BVW were associated with a history of a prior ipsilateral CVC (odds ratio [OR] = 4.5, 95% confidence interval [CI] = 1.6-12.6, P = 0.009). Of the 342 patients, 69 (20%) had a venogram within 6 months. Seventeen (25%) of the 69 patients had CVS, with 7 involving the left subclavian vein, 8 the right subclavian vein, and 3 the superior vena cava (one patient had tandem stenoses). A BVW on the left side was not associated with any CVS. A BVW on the right side was associated with an ipsilateral CVS (OR = 5.8, 95% CI = 1.2-27.4, P = 0.04). This association persisted in the setting of a prior CVC (relative risk = 1.3, 95% CI = 0.9-2, P = 0.01).

CONCLUSIONS

There are associations between right-sided BVW and an ipsilateral subclavian vein stenosis. We recommend that hemodialysis access planning includes venography to rule out central vein stenosis in patients with BVW, especially if right-sided and in the setting of a prior CVC.