How much guidewire is too much? Direct measurement of the distance from subclavian and internal jugular vein access sites to the superior vena cava-atrial junction during central venous catheter placement.

OBJECTIVE: The introduction of excessive lengths of guidewire during placement of central venous catheters from the internal jugular vein (IJV) or the subclavian vein (SCV) can result in rare but significant complications. To identify a "safe" guidewire insertion length, the authors performed direct intravascular measurement of the distance from these venous access sites to the superior vena cava-atrial junction (CAJ), and evaluated these distances relative to the patients' height, weight, sex, and chest radiographs.

DESIGN: Prospective, nonrandomized observation.

SETTING: The Interventional Radiology Department of a tertiary care referral hospital.

PATIENTS: 100 adults (45 women, 55 men) evaluated during fluoroscopically directed central venous catheter placement.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: The distance from the IJV or SCV access site was directly measured using fluoroscopy and an intravascular guidewire. 40 right IJVs, 31 right SCVs, 16 left SCVs, and 13 left IJVs were studied. Comparative measurements from the postprocedure radiograph were made in 20 of these cases. All measurements were correlated with patient sex, height, and weight. The mean distance from all access sites to the superior vena cava-atrial junction was 18.0 cm. The right IJV distance was the shortest, averaging 16 cm. The left SCV distance was the longest, averaging 21.2 cm. Right SCV and left IJV distances were 18.4 and 19.1 cm, respectively, but this difference was not statistically significant. Weight and radiographic measurements did not correlate with the measured vascular distance, although there was a trend toward longer distances in taller patients and males.

CONCLUSIONS: Patient height, weight, and measurements from previous chest radiographs are less reliable in predicting a safe wire length than is the access site selected. In most cases, 18 cm should be considered the upper limit of guidewire introduced during central catheter placement in adults. The guidewires supplied in catheter kits should have lengths correlated to those of the catheters, and should have distance markings printed upon them.