Carbon-dioxide-guided vascular interventions: technique and pitfalls.

PURPOSE: To evaluate the usefulness of carbon dioxide (CO2) angiography to guide vascular interventions. METHODS: A prospective study was carried out of 50 procedures (angioplasty, stenting, stent-grafting and embolization) using CO2 angiography. Indications for using CO2 were renal impairment, cardiac failure, previous reaction to conventional iodinated contrast, or likelihood of needing high doses of conventional contrast. CO2 was intended to be the sole contrast agent. The use of additional conventional contrast or gadolinium was recorded, as were procedural complications. Radiation dose was compared with similar procedures using conventional contrast. RESULTS: Angiographic quality was satisfactory in 44 (88%) procedures and CO2 guidance was all that was required; in 6 (12%) cases adjunctive use of conventional contrast or gadolinium was necessary. Contrast doses were significantly reduced and there was a trend toward decreased radiation doses with CO2. There were two significant complications but only one related to the use of CO2. CONCLUSION: CO2 angiography is well tolerated and can be successfully used to guide even complex vascular interventions. High-risk patients can be spared the risks of conventional contrast agents.

Routine chest radiography following imaging-guided placement of tunneled central lines: a waste of time, money, and radiation.

BACKGROUND: This study sought to evaluate routine chest radiography following placement of tunneled central lines using combined ultrasound and fluoroscopic guidance. MATERIALS AND METHODS: A prospective study of 150 consecutive patients who underwent placement of tunneled central lines in the vascular radiology suite. Ultrasound-guided vein puncture was performed with an 18-gauge needle in each case, and the access site was noted. Line position was confirmed by fluoroscopy. Following the procedure, 50 patients had both an on-table digital chest radiograph and a conventional chest radiograph. Subsequent patients had a digital radiograph and a fluoroscopic image grab. Final line tip position was scored, and complications were recorded. RESULTS: Line placement was optimal (95%) or acceptable (5%) in all patients. Line tip position could be satisfactorily evaluated on supine fluoroscopy. Mean fluoroscopic x-ray dose was 0.5 cGy/cm2. Digital chest x-ray dose was 9.0 cGy/cm2, and formal chest radiography dose was 12.0 cGy/cm2. The only complications were 2 carotid artery punctures without clinical sequelae. CONCLUSION: When lines are placed under imaging guidance with ultrasound to direct the venous puncture, complications are rare and are not likely to be clinically important. Conventional and digital chest radiographs do not contribute clinically relevant information but do add to the radiation dose, time, and expense of the procedure.